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Diffstat (limited to 'linux/src/drivers/scsi/NCR5380.c')
| -rw-r--r-- | linux/src/drivers/scsi/NCR5380.c | 3247 |
1 files changed, 3247 insertions, 0 deletions
diff --git a/linux/src/drivers/scsi/NCR5380.c b/linux/src/drivers/scsi/NCR5380.c new file mode 100644 index 0000000..e6fc75c --- /dev/null +++ b/linux/src/drivers/scsi/NCR5380.c @@ -0,0 +1,3247 @@ +#ifndef NDEBUG +#define NDEBUG (NDEBUG_RESTART_SELECT | NDEBUG_ABORT) +#endif +/* + * NCR 5380 generic driver routines. These should make it *trivial* + * to implement 5380 SCSI drivers under Linux with a non-trantor + * architecture. + * + * Note that these routines also work with NR53c400 family chips. + * + * Copyright 1993, Drew Eckhardt + * Visionary Computing + * (Unix and Linux consulting and custom programming) + * drew@colorado.edu + * +1 (303) 666-5836 + * + * DISTRIBUTION RELEASE 6. + * + * For more information, please consult + * + * NCR 5380 Family + * SCSI Protocol Controller + * Databook + * + * NCR Microelectronics + * 1635 Aeroplaza Drive + * Colorado Springs, CO 80916 + * 1+ (719) 578-3400 + * 1+ (800) 334-5454 + */ + +/* + * $Log: NCR5380.c,v $ + * Revision 1.7 1996/3/2 Ray Van Tassle (rayvt@comm.mot.com) + * added proc_info + * added support needed for DTC 3180/3280 + * fixed a couple of bugs + * + + * Revision 1.5 1994/01/19 09:14:57 drew + * Fixed udelay() hack that was being used on DATAOUT phases + * instead of a proper wait for the final handshake. + * + * Revision 1.4 1994/01/19 06:44:25 drew + * *** empty log message *** + * + * Revision 1.3 1994/01/19 05:24:40 drew + * Added support for TCR LAST_BYTE_SENT bit. + * + * Revision 1.2 1994/01/15 06:14:11 drew + * REAL DMA support, bug fixes. + * + * Revision 1.1 1994/01/15 06:00:54 drew + * Initial revision + * + */ + +/* + * Further development / testing that should be done : + * 1. Cleanup the NCR5380_transfer_dma function and DMA operation complete + * code so that everything does the same thing that's done at the + * end of a pseudo-DMA read operation. + * + * 2. Fix REAL_DMA (interrupt driven, polled works fine) - + * basically, transfer size needs to be reduced by one + * and the last byte read as is done with PSEUDO_DMA. + * + * 3. Test USLEEP code + * + * 4. Test SCSI-II tagged queueing (I have no devices which support + * tagged queueing) + * + * 5. Test linked command handling code after Eric is ready with + * the high level code. + */ + +#if (NDEBUG & NDEBUG_LISTS) +#define LIST(x,y) {printk("LINE:%d Adding %p to %p\n", __LINE__, (void*)(x), (void*)(y)); if ((x)==(y)) udelay(5); } +#define REMOVE(w,x,y,z) {printk("LINE:%d Removing: %p->%p %p->%p \n", __LINE__, (void*)(w), (void*)(x), (void*)(y), (void*)(z)); if ((x)==(y)) udelay(5); } +#else +#define LIST(x,y) +#define REMOVE(w,x,y,z) +#endif + +#ifndef notyet +#undef LINKED +#undef USLEEP +#undef REAL_DMA +#endif + +#ifdef REAL_DMA_POLL +#undef READ_OVERRUNS +#define READ_OVERRUNS +#endif + +/* + * Design + * Issues : + * + * The other Linux SCSI drivers were written when Linux was Intel PC-only, + * and specifically for each board rather than each chip. This makes their + * adaptation to platforms like the Mac (Some of which use NCR5380's) + * more difficult than it has to be. + * + * Also, many of the SCSI drivers were written before the command queuing + * routines were implemented, meaning their implementations of queued + * commands were hacked on rather than designed in from the start. + * + * When I designed the Linux SCSI drivers I figured that + * while having two different SCSI boards in a system might be useful + * for debugging things, two of the same type wouldn't be used. + * Well, I was wrong and a number of users have mailed me about running + * multiple high-performance SCSI boards in a server. + * + * Finally, when I get questions from users, I have no idea what + * revision of my driver they are running. + * + * This driver attempts to address these problems : + * This is a generic 5380 driver. To use it on a different platform, + * one simply writes appropriate system specific macros (ie, data + * transfer - some PC's will use the I/O bus, 68K's must use + * memory mapped) and drops this file in their 'C' wrapper. + * + * As far as command queueing, two queues are maintained for + * each 5380 in the system - commands that haven't been issued yet, + * and commands that are currently executing. This means that an + * unlimited number of commands may be queued, letting + * more commands propagate from the higher driver levels giving higher + * throughput. Note that both I_T_L and I_T_L_Q nexuses are supported, + * allowing multiple commands to propagate all the way to a SCSI-II device + * while a command is already executing. + * + * To solve the multiple-boards-in-the-same-system problem, + * there is a separate instance structure for each instance + * of a 5380 in the system. So, multiple NCR5380 drivers will + * be able to coexist with appropriate changes to the high level + * SCSI code. + * + * A NCR5380_PUBLIC_REVISION macro is provided, with the release + * number (updated for each public release) printed by the + * NCR5380_print_options command, which should be called from the + * wrapper detect function, so that I know what release of the driver + * users are using. + * + * Issues specific to the NCR5380 : + * + * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead + * piece of hardware that requires you to sit in a loop polling for + * the REQ signal as long as you are connected. Some devices are + * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect + * while doing long seek operations. + * + * The workaround for this is to keep track of devices that have + * disconnected. If the device hasn't disconnected, for commands that + * should disconnect, we do something like + * + * while (!REQ is asserted) { sleep for N usecs; poll for M usecs } + * + * Some tweaking of N and M needs to be done. An algorithm based + * on "time to data" would give the best results as long as short time + * to datas (ie, on the same track) were considered, however these + * broken devices are the exception rather than the rule and I'd rather + * spend my time optimizing for the normal case. + * + * Architecture : + * + * At the heart of the design is a coroutine, NCR5380_main, + * which is started when not running by the interrupt handler, + * timer, and queue command function. It attempts to establish + * I_T_L or I_T_L_Q nexuses by removing the commands from the + * issue queue and calling NCR5380_select() if a nexus + * is not established. + * + * Once a nexus is established, the NCR5380_information_transfer() + * phase goes through the various phases as instructed by the target. + * if the target goes into MSG IN and sends a DISCONNECT message, + * the command structure is placed into the per instance disconnected + * queue, and NCR5380_main tries to find more work. If USLEEP + * was defined, and the target is idle for too long, the system + * will try to sleep. + * + * If a command has disconnected, eventually an interrupt will trigger, + * calling NCR5380_intr() which will in turn call NCR5380_reselect + * to reestablish a nexus. This will run main if necessary. + * + * On command termination, the done function will be called as + * appropriate. + * + * SCSI pointers are maintained in the SCp field of SCSI command + * structures, being initialized after the command is connected + * in NCR5380_select, and set as appropriate in NCR5380_information_transfer. + * Note that in violation of the standard, an implicit SAVE POINTERS operation + * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS. + */ + +/* + * Using this file : + * This file a skeleton Linux SCSI driver for the NCR 5380 series + * of chips. To use it, you write a architecture specific functions + * and macros and include this file in your driver. + * + * These macros control options : + * AUTOPROBE_IRQ - if defined, the NCR5380_probe_irq() function will be + * defined. + * + * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically + * for commands that return with a CHECK CONDITION status. + * + * DIFFERENTIAL - if defined, NCR53c81 chips will use external differential + * transceivers. + * + * DONT_USE_INTR - if defined, never use interrupts, even if we probe or + * override-configure an IRQ. + * + * LIMIT_TRANSFERSIZE - if defined, limit the pseudo-dma transfers to 512 + * bytes at a time. Since interrupts are disabled by default during + * these transfers, we might need this to give reasonable interrupt + * service time if the transfer size gets too large. + * + * LINKED - if defined, linked commands are supported. + * + * PSEUDO_DMA - if defined, PSEUDO DMA is used during the data transfer phases. + * + * REAL_DMA - if defined, REAL DMA is used during the data transfer phases. + * + * REAL_DMA_POLL - if defined, REAL DMA is used but the driver doesn't + * rely on phase mismatch and EOP interrupts to determine end + * of phase. + * + * SCSI2 - if defined, SCSI-2 tagged queuing is used where possible + * + * UNSAFE - leave interrupts enabled during pseudo-DMA transfers. You + * only really want to use this if you're having a problem with + * dropped characters during high speed communications, and even + * then, you're going to be better off twiddling with transfersize + * in the high level code. + * + * USLEEP - if defined, on devices that aren't disconnecting from the + * bus, we will go to sleep so that the CPU can get real work done + * when we run a command that won't complete immediately. + * + * Note that if USLEEP is defined, NCR5380_TIMER *must* also be + * defined. + * + * Defaults for these will be provided if USLEEP is defined, although + * the user may want to adjust these to allocate CPU resources to + * the SCSI driver or "real" code. + * + * USLEEP_SLEEP - amount of time, in jiffies, to sleep + * + * USLEEP_POLL - amount of time, in jiffies, to poll + * + * These macros MUST be defined : + * NCR5380_local_declare() - declare any local variables needed for your + * transfer routines. + * + * NCR5380_setup(instance) - initialize any local variables needed from a given + * instance of the host adapter for NCR5380_{read,write,pread,pwrite} + * + * NCR5380_read(register) - read from the specified register + * + * NCR5380_write(register, value) - write to the specific register + * + * NCR5380_implementation_fields - additional fields needed for this + * specific implementation of the NCR5380 + * + * Either real DMA *or* pseudo DMA may be implemented + * REAL functions : + * NCR5380_REAL_DMA should be defined if real DMA is to be used. + * Note that the DMA setup functions should return the number of bytes + * that they were able to program the controller for. + * + * Also note that generic i386/PC versions of these macros are + * available as NCR5380_i386_dma_write_setup, + * NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual. + * + * NCR5380_dma_write_setup(instance, src, count) - initialize + * NCR5380_dma_read_setup(instance, dst, count) - initialize + * NCR5380_dma_residual(instance); - residual count + * + * PSEUDO functions : + * NCR5380_pwrite(instance, src, count) + * NCR5380_pread(instance, dst, count); + * + * If nothing specific to this implementation needs doing (ie, with external + * hardware), you must also define + * + * NCR5380_queue_command + * NCR5380_reset + * NCR5380_abort + * NCR5380_proc_info + * + * to be the global entry points into the specific driver, ie + * #define NCR5380_queue_command t128_queue_command. + * + * If this is not done, the routines will be defined as static functions + * with the NCR5380* names and the user must provide a globally + * accessible wrapper function. + * + * The generic driver is initialized by calling NCR5380_init(instance), + * after setting the appropriate host specific fields and ID. If the + * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance, + * possible) function may be used. Before the specific driver initialization + * code finishes, NCR5380_print_options should be called. + */ + +static int do_abort (struct Scsi_Host *host); +static void do_reset (struct Scsi_Host *host); +static struct Scsi_Host *first_instance = NULL; +static Scsi_Host_Template *the_template = NULL; + +/* + * Function : void initialize_SCp(Scsi_Cmnd *cmd) + * + * Purpose : initialize the saved data pointers for cmd to point to the + * start of the buffer. + * + * Inputs : cmd - Scsi_Cmnd structure to have pointers reset. + */ + +static __inline__ void initialize_SCp(Scsi_Cmnd *cmd) { + /* + * Initialize the Scsi Pointer field so that all of the commands in the + * various queues are valid. + */ + + if (cmd->use_sg) { + cmd->SCp.buffer = (struct scatterlist *) cmd->buffer; + cmd->SCp.buffers_residual = cmd->use_sg - 1; + cmd->SCp.ptr = (char *) cmd->SCp.buffer->address; + cmd->SCp.this_residual = cmd->SCp.buffer->length; + } else { + cmd->SCp.buffer = NULL; + cmd->SCp.buffers_residual = 0; + cmd->SCp.ptr = (char *) cmd->request_buffer; + cmd->SCp.this_residual = cmd->request_bufflen; + } +} + +#include <linux/delay.h> + +#ifdef NDEBUG +static struct { + unsigned char mask; + const char * name;} +signals[] = {{ SR_DBP, "PARITY"}, { SR_RST, "RST" }, { SR_BSY, "BSY" }, + { SR_REQ, "REQ" }, { SR_MSG, "MSG" }, { SR_CD, "CD" }, { SR_IO, "IO" }, + { SR_SEL, "SEL" }, {0, NULL}}, +basrs[] = {{BASR_ATN, "ATN"}, {BASR_ACK, "ACK"}, {0, NULL}}, +icrs[] = {{ICR_ASSERT_RST, "ASSERT RST"},{ICR_ASSERT_ACK, "ASSERT ACK"}, + {ICR_ASSERT_BSY, "ASSERT BSY"}, {ICR_ASSERT_SEL, "ASSERT SEL"}, + {ICR_ASSERT_ATN, "ASSERT ATN"}, {ICR_ASSERT_DATA, "ASSERT DATA"}, + {0, NULL}}, +mrs[] = {{MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"}, {MR_TARGET, "MODE TARGET"}, + {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"}, {MR_ENABLE_PAR_INTR, + "MODE PARITY INTR"}, {MR_MONITOR_BSY, "MODE MONITOR BSY"}, + {MR_DMA_MODE, "MODE DMA"}, {MR_ARBITRATE, "MODE ARBITRATION"}, + {0, NULL}}; + +/* + * Function : void NCR5380_print(struct Scsi_Host *instance) + * + * Purpose : print the SCSI bus signals for debugging purposes + * + * Input : instance - which NCR5380 + */ + +static void NCR5380_print(struct Scsi_Host *instance) { + NCR5380_local_declare(); + unsigned char status, data, basr, mr, icr, i; + NCR5380_setup(instance); + cli(); + data = NCR5380_read(CURRENT_SCSI_DATA_REG); + status = NCR5380_read(STATUS_REG); + mr = NCR5380_read(MODE_REG); + icr = NCR5380_read(INITIATOR_COMMAND_REG); + basr = NCR5380_read(BUS_AND_STATUS_REG); + sti(); + printk("STATUS_REG: %02x ", status); + for (i = 0; signals[i].mask ; ++i) + if (status & signals[i].mask) + printk(",%s", signals[i].name); + printk("\nBASR: %02x ", basr); + for (i = 0; basrs[i].mask ; ++i) + if (basr & basrs[i].mask) + printk(",%s", basrs[i].name); + printk("\nICR: %02x ", icr); + for (i = 0; icrs[i].mask; ++i) + if (icr & icrs[i].mask) + printk(",%s", icrs[i].name); + printk("\nMODE: %02x ", mr); + for (i = 0; mrs[i].mask; ++i) + if (mr & mrs[i].mask) + printk(",%s", mrs[i].name); + printk("\n"); +} + +static struct { + unsigned char value; + const char *name; +} phases[] = { +{PHASE_DATAOUT, "DATAOUT"}, {PHASE_DATAIN, "DATAIN"}, {PHASE_CMDOUT, "CMDOUT"}, +{PHASE_STATIN, "STATIN"}, {PHASE_MSGOUT, "MSGOUT"}, {PHASE_MSGIN, "MSGIN"}, +{PHASE_UNKNOWN, "UNKNOWN"}}; + +/* + * Function : void NCR5380_print_phase(struct Scsi_Host *instance) + * + * Purpose : print the current SCSI phase for debugging purposes + * + * Input : instance - which NCR5380 + */ + +static void NCR5380_print_phase(struct Scsi_Host *instance) { + NCR5380_local_declare(); + unsigned char status; + int i; + NCR5380_setup(instance); + + status = NCR5380_read(STATUS_REG); + if (!(status & SR_REQ)) + printk("scsi%d : REQ not asserted, phase unknown.\n", + instance->host_no); + else { + for (i = 0; (phases[i].value != PHASE_UNKNOWN) && + (phases[i].value != (status & PHASE_MASK)); ++i); + printk("scsi%d : phase %s\n", instance->host_no, phases[i].name); + } +} +#endif + +/* + * We need to have our coroutine active given these constraints : + * 1. The mutex flag, main_running, can only be set when the main + * routine can actually process data, otherwise SCSI commands + * will never get issued. + * + * 2. NCR5380_main() shouldn't be called before it has exited, because + * other drivers have had kernel stack overflows in similar + * situations. + * + * 3. We don't want to inline NCR5380_main() because of space concerns, + * even though it is only called in two places. + * + * So, the solution is to set the mutex in an inline wrapper for the + * main coroutine, and have the main coroutine exit with interrupts + * disabled after the final search through the queues so that no race + * conditions are possible. + */ + +static volatile int main_running = 0; + +/* + * Function : run_main(void) + * + * Purpose : insure that the coroutine is running and will process our + * request. main_running is checked/set here (in an inline function) + * rather than in NCR5380_main itself to reduce the chances of stack + * overflow. + * + */ + +static __inline__ void run_main(void) { + cli(); + if (!main_running) { + main_running = 1; + NCR5380_main(); + /* + * main_running is cleared in NCR5380_main once it can't do + * more work, and NCR5380_main exits with interrupts disabled. + */ + sti(); + } else + sti(); +} + +#ifdef USLEEP +#ifndef NCR5380_TIMER +#error "NCR5380_TIMER must be defined so that this type of NCR5380 driver gets a unique timer." +#endif + +/* + * These need tweaking, and would probably work best as per-device + * flags initialized differently for disk, tape, cd, etc devices. + * People with broken devices are free to experiment as to what gives + * the best results for them. + * + * USLEEP_SLEEP should be a minimum seek time. + * + * USLEEP_POLL should be a maximum rotational latency. + */ +#ifndef USLEEP_SLEEP +/* 20 ms (reasonable hard disk speed) */ +#define USLEEP_SLEEP (20*HZ/1000) +#endif +/* 300 RPM (floppy speed) */ +#ifndef USLEEP_POLL +#define USLEEP_POLL (200*HZ/1000) +#endif + +static struct Scsi_Host * expires_first = NULL; + +/* + * Function : int should_disconnect (unsigned char cmd) + * + * Purpose : decide weather a command would normally disconnect or + * not, since if it won't disconnect we should go to sleep. + * + * Input : cmd - opcode of SCSI command + * + * Returns : DISCONNECT_LONG if we should disconnect for a really long + * time (ie always, sleep, look for REQ active, sleep), + * DISCONNECT_TIME_TO_DATA if we would only disconnect for a normal + * time-to-data delay, DISCONNECT_NONE if this command would return + * immediately. + * + * Future sleep algorithms based on time to data can exploit + * something like this so they can differentiate between "normal" + * (ie, read, write, seek) and unusual commands (ie, * format). + * + * Note : We don't deal with commands that handle an immediate disconnect, + * + */ + +static int should_disconnect (unsigned char cmd) { + switch (cmd) { + case READ_6: + case WRITE_6: + case SEEK_6: + case READ_10: + case WRITE_10: + case SEEK_10: + return DISCONNECT_TIME_TO_DATA; + case FORMAT_UNIT: + case SEARCH_HIGH: + case SEARCH_LOW: + case SEARCH_EQUAL: + return DISCONNECT_LONG; + default: + return DISCONNECT_NONE; + } +} + +/* + * Assumes instance->time_expires has been set in higher level code. + */ + +static int NCR5380_set_timer (struct Scsi_Host *instance) { + struct Scsi_Host *tmp, **prev; + + cli(); + if (((struct NCR5380_hostdata *) (instance->host_data))->next_timer) { + sti(); + return -1; + } + + for (prev = &expires_first, tmp = expires_first; tmp; + prev = &(((struct NCR5380_hostdata *) tmp->host_data)->next_timer), + tmp = ((struct NCR5380_hostdata *) tmp->host_data)->next_timer) + if (instance->time_expires < tmp->time_expires) + break; + + instance->next_timer = tmp; + *prev = instance; + timer_table[NCR5380_TIMER].expires = expires_first->time_expires; + timer_active |= 1 << NCR5380_TIMER; + sti(); + return 0; +} + +/* Doing something about unwanted reentrancy here might be useful */ +void NCR5380_timer_fn(void) { + struct Scsi_Host *instance; + cli(); + for (; expires_first && expires_first->time_expires >= jiffies; ) { + instance = ((NCR5380_hostdata *) expires_first->host_data)-> + expires_next; + ((NCR5380_hostdata *) expires_first->host_data)->expires_next = + NULL; + ((NCR5380_hostdata *) expires_first->host_data)->time_expires = + 0; + expires_first = instance; + } + + if (expires_first) { + timer_table[NCR5380_TIMER].expires = ((NCR5380_hostdata *) + expires_first->host_data)->time_expires; + timer_active |= (1 << NCR5380_TIMER); + } else { + timer_table[NCR5380_TIMER].expires = 0; + timer_active &= ~(1 << MCR5380_TIMER); + } + sti(); + + run_main(); +} +#endif /* def USLEEP */ + +static void NCR5380_all_init (void) { + static int done = 0; + if (!done) { +#if (NDEBUG & NDEBUG_INIT) + printk("scsi : NCR5380_all_init()\n"); +#endif + done = 1; +#ifdef USLEEP + timer_table[NCR5380_TIMER].expires = 0; + timer_table[NCR5380_TIMER].fn = NCR5380_timer_fn; +#endif + } +} + +#ifdef AUTOPROBE_IRQ +/* + * Function : int NCR5380_probe_irq (struct Scsi_Host *instance, int possible) + * + * Purpose : autoprobe for the IRQ line used by the NCR5380. + * + * Inputs : instance - pointer to this instance of the NCR5380 driver, + * possible - bitmask of permissible interrupts. + * + * Returns : number of the IRQ selected, IRQ_NONE if no interrupt fired. + * + * XXX no effort is made to deal with spurious interrupts. + */ + + +static int probe_irq; +static void probe_intr (int irq, void *dev_id, struct pt_regs * regs) { + probe_irq = irq; +}; + +static int NCR5380_probe_irq (struct Scsi_Host *instance, int possible) { + NCR5380_local_declare(); + struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) + instance->hostdata; + unsigned long timeout; + int trying_irqs, i, mask; + NCR5380_setup(instance); + + for (trying_irqs = i = 0, mask = 1; i < 16; ++i, mask <<= 1) + if ((mask & possible) && (request_irq(i, &probe_intr, SA_INTERRUPT, "NCR-probe", NULL) + == 0)) + trying_irqs |= mask; + + timeout = jiffies + 250*HZ/1000; + probe_irq = IRQ_NONE; + +/* + * A interrupt is triggered whenever BSY = false, SEL = true + * and a bit set in the SELECT_ENABLE_REG is asserted on the + * SCSI bus. + * + * Note that the bus is only driven when the phase control signals + * (I/O, C/D, and MSG) match those in the TCR, so we must reset that + * to zero. + */ + + NCR5380_write(TARGET_COMMAND_REG, 0); + NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); + NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask); + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | + ICR_ASSERT_SEL); + + while (probe_irq == IRQ_NONE && jiffies < timeout) + barrier(); + + NCR5380_write(SELECT_ENABLE_REG, 0); + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + + for (i = 0, mask = 1; i < 16; ++i, mask <<= 1) + if (trying_irqs & mask) + free_irq(i, NULL); + + return probe_irq; +} +#endif /* AUTOPROBE_IRQ */ + +/* + * Function : void NCR58380_print_options (struct Scsi_Host *instance) + * + * Purpose : called by probe code indicating the NCR5380 driver + * options that were selected. + * + * Inputs : instance, pointer to this instance. Unused. + */ + +static void NCR5380_print_options (struct Scsi_Host *instance) { + printk(" generic options" +#ifdef AUTOPROBE_IRQ + " AUTOPROBE_IRQ" +#endif +#ifdef AUTOSENSE + " AUTOSENSE" +#endif +#ifdef DIFFERENTIAL + " DIFFERENTIAL" +#endif +#ifdef REAL_DMA + " REAL DMA" +#endif +#ifdef REAL_DMA_POLL + " REAL DMA POLL" +#endif +#ifdef PARITY + " PARITY" +#endif +#ifdef PSEUDO_DMA + " PSEUDO DMA" +#endif +#ifdef SCSI2 + " SCSI-2" +#endif +#ifdef UNSAFE + " UNSAFE " +#endif + ); +#ifdef USLEEP + printk(" USLEEP, USLEEP_POLL=%d USLEEP_SLEEP=%d", USLEEP_POLL, USLEEP_SLEEP); +#endif + printk(" generic release=%d", NCR5380_PUBLIC_RELEASE); + if (((struct NCR5380_hostdata *)instance->hostdata)->flags & FLAG_NCR53C400) { + printk(" ncr53c400 release=%d", NCR53C400_PUBLIC_RELEASE); + } +} + +/* + * Function : void NCR5380_print_status (struct Scsi_Host *instance) + * + * Purpose : print commands in the various queues, called from + * NCR5380_abort and NCR5380_debug to aid debugging. + * + * Inputs : instance, pointer to this instance. + */ + +static void NCR5380_print_status (struct Scsi_Host *instance) { + static char pr_bfr[512]; + char *start; + int len; + + printk("NCR5380 : coroutine is%s running.\n", + main_running ? "" : "n't"); + +#ifdef NDEBUG + NCR5380_print (instance); + NCR5380_print_phase (instance); +#endif + + len = NCR5380_proc_info(pr_bfr, &start, 0, sizeof(pr_bfr), + instance->host_no, 0); + pr_bfr[len] = 0; + printk("\n%s\n", pr_bfr); + } + +/******************************************/ +/* + * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED] + * + * *buffer: I/O buffer + * **start: if inout == FALSE pointer into buffer where user read should start + * offset: current offset + * length: length of buffer + * hostno: Scsi_Host host_no + * inout: TRUE - user is writing; FALSE - user is reading + * + * Return the number of bytes read from or written +*/ + +#undef SPRINTF +#define SPRINTF(args...) do { if(pos < buffer + length-80) pos += sprintf(pos, ## args); } while(0) +static +char *lprint_Scsi_Cmnd (Scsi_Cmnd *cmd, char *pos, char *buffer, int length); +static +char *lprint_command (unsigned char *cmd, char *pos, char *buffer, int len); +static +char *lprint_opcode(int opcode, char *pos, char *buffer, int length); + +#ifndef NCR5380_proc_info +static +#endif +int NCR5380_proc_info ( + char *buffer, char **start,off_t offset, + int length,int hostno,int inout) +{ + char *pos = buffer; + struct Scsi_Host *instance; + struct NCR5380_hostdata *hostdata; + Scsi_Cmnd *ptr; + + for (instance = first_instance; instance && + instance->host_no != hostno; instance=instance->next) + ; + if (!instance) + return(-ESRCH); + hostdata = (struct NCR5380_hostdata *)instance->hostdata; + + if (inout) { /* Has data been written to the file ? */ +#ifdef DTC_PUBLIC_RELEASE + dtc_wmaxi = dtc_maxi = 0; +#endif +#ifdef PAS16_PUBLIC_RELEASE + pas_wmaxi = pas_maxi = 0; +#endif + return(-ENOSYS); /* Currently this is a no-op */ + } + SPRINTF("NCR5380 core release=%d. ", NCR5380_PUBLIC_RELEASE); + if (((struct NCR5380_hostdata *)instance->hostdata)->flags & FLAG_NCR53C400) + SPRINTF("ncr53c400 release=%d. ", NCR53C400_PUBLIC_RELEASE); +#ifdef DTC_PUBLIC_RELEASE + SPRINTF("DTC 3180/3280 release %d", DTC_PUBLIC_RELEASE); +#endif +#ifdef T128_PUBLIC_RELEASE + SPRINTF("T128 release %d", T128_PUBLIC_RELEASE); +#endif +#ifdef GENERIC_NCR5380_PUBLIC_RELEASE + SPRINTF("Generic5380 release %d", GENERIC_NCR5380_PUBLIC_RELEASE); +#endif +#ifdef PAS16_PUBLIC_RELEASE +SPRINTF("PAS16 release=%d", PAS16_PUBLIC_RELEASE); +#endif + + SPRINTF("\nBase Addr: 0x%05lX ", (long)instance->base); + SPRINTF("io_port: %04x ", (int)instance->io_port); + if (instance->irq == IRQ_NONE) + SPRINTF("IRQ: None.\n"); + else + SPRINTF("IRQ: %d.\n", instance->irq); + +#ifdef DTC_PUBLIC_RELEASE + SPRINTF("Highwater I/O busy_spin_counts -- write: %d read: %d\n", + dtc_wmaxi, dtc_maxi); +#endif +#ifdef PAS16_PUBLIC_RELEASE + SPRINTF("Highwater I/O busy_spin_counts -- write: %d read: %d\n", + pas_wmaxi, pas_maxi); +#endif + cli(); + SPRINTF("NCR5380 : coroutine is%s running.\n", main_running ? "" : "n't"); + if (!hostdata->connected) + SPRINTF("scsi%d: no currently connected command\n", instance->host_no); + else + pos = lprint_Scsi_Cmnd ((Scsi_Cmnd *) hostdata->connected, + pos, buffer, length); + SPRINTF("scsi%d: issue_queue\n", instance->host_no); + for (ptr = (Scsi_Cmnd *) hostdata->issue_queue; ptr; + ptr = (Scsi_Cmnd *) ptr->host_scribble) + pos = lprint_Scsi_Cmnd (ptr, pos, buffer, length); + + SPRINTF("scsi%d: disconnected_queue\n", instance->host_no); + for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr; + ptr = (Scsi_Cmnd *) ptr->host_scribble) + pos = lprint_Scsi_Cmnd (ptr, pos, buffer, length); + + sti(); + *start=buffer; + if (pos - buffer < offset) + return 0; + else if (pos - buffer - offset < length) + return pos - buffer - offset; + return length; +} + +static +char *lprint_Scsi_Cmnd (Scsi_Cmnd *cmd, char *pos, char *buffer, int length) { + SPRINTF("scsi%d : destination target %d, lun %d\n", + cmd->host->host_no, cmd->target, cmd->lun); + SPRINTF(" command = "); + pos = lprint_command (cmd->cmnd, pos, buffer, length); + return (pos); +} + +static +char *lprint_command (unsigned char *command, + char *pos, char *buffer, int length) { + int i, s; + pos = lprint_opcode(command[0], pos, buffer, length); + for ( i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i) + SPRINTF("%02x ", command[i]); + SPRINTF("\n"); + return(pos); +} + +static +char *lprint_opcode(int opcode, char *pos, char *buffer, int length) { + SPRINTF("%2d (0x%02x)", opcode, opcode); + return(pos); +} + + +/* + * Function : void NCR5380_init (struct Scsi_Host *instance, flags) + * + * Purpose : initializes *instance and corresponding 5380 chip, + * with flags OR'd into the initial flags value. + * + * Inputs : instance - instantiation of the 5380 driver. + * + * Notes : I assume that the host, hostno, and id bits have been + * set correctly. I don't care about the irq and other fields. + * + */ + +static void NCR5380_init (struct Scsi_Host *instance, int flags) { + NCR5380_local_declare(); + int i, pass; + unsigned long timeout; + struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) + instance->hostdata; + + /* + * On NCR53C400 boards, NCR5380 registers are mapped 8 past + * the base address. + */ + +#ifdef NCR53C400 + if (flags & FLAG_NCR53C400) + instance->NCR5380_instance_name += NCR53C400_address_adjust; +#endif + + NCR5380_setup(instance); + + NCR5380_all_init(); + + hostdata->aborted = 0; + hostdata->id_mask = 1 << instance->this_id; + for (i = hostdata->id_mask; i <= 0x80; i <<= 1) + if (i > hostdata->id_mask) + hostdata->id_higher_mask |= i; + for (i = 0; i < 8; ++i) + hostdata->busy[i] = 0; +#ifdef REAL_DMA + hostdata->dmalen = 0; +#endif + hostdata->targets_present = 0; + hostdata->connected = NULL; + hostdata->issue_queue = NULL; + hostdata->disconnected_queue = NULL; +#ifdef NCR5380_STATS + for (i = 0; i < 8; ++i) { + hostdata->time_read[i] = 0; + hostdata->time_write[i] = 0; + hostdata->bytes_read[i] = 0; + hostdata->bytes_write[i] = 0; + } + hostdata->timebase = 0; + hostdata->pendingw = 0; + hostdata->pendingr = 0; +#endif + + /* The CHECK code seems to break the 53C400. Will check it later maybe */ + if (flags & FLAG_NCR53C400) + hostdata->flags = FLAG_HAS_LAST_BYTE_SENT | flags; + else + hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT | flags; + + if (!the_template) { + the_template = instance->hostt; + first_instance = instance; + } + + +#ifdef USLEEP + hostdata->time_expires = 0; + hostdata->next_timer = NULL; +#endif + +#ifndef AUTOSENSE + if ((instance->cmd_per_lun > 1) || instance->can_queue > 1)) + printk("scsi%d : WARNING : support for multiple outstanding commands enabled\n" + " without AUTOSENSE option, contingent allegiance conditions may\n" + " be incorrectly cleared.\n", instance->host_no); +#endif /* def AUTOSENSE */ + + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + NCR5380_write(MODE_REG, MR_BASE); + NCR5380_write(TARGET_COMMAND_REG, 0); + NCR5380_write(SELECT_ENABLE_REG, 0); + +#ifdef NCR53C400 + if (hostdata->flags & FLAG_NCR53C400) { + NCR5380_write(C400_CONTROL_STATUS_REG, CSR_BASE); + } +#endif + + /* + * Detect and correct bus wedge problems. + * + * If the system crashed, it may have crashed in a state + * where a SCSI command was still executing, and the + * SCSI bus is not in a BUS FREE STATE. + * + * If this is the case, we'll try to abort the currently + * established nexus which we know nothing about, and that + * failing, do a hard reset of the SCSI bus + */ + + for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && + pass <= 6 ; ++pass) { + switch (pass) { + case 1: + case 3: + case 5: + printk("scsi%d: SCSI bus busy, waiting up to five seconds\n", + instance->host_no); + timeout = jiffies + 5*HZ; + while (jiffies < timeout && (NCR5380_read(STATUS_REG) & SR_BSY)); + break; + case 2: + printk("scsi%d: bus busy, attempting abort\n", + instance->host_no); + do_abort (instance); + break; + case 4: + printk("scsi%d: bus busy, attempting reset\n", + instance->host_no); + do_reset (instance); + break; + case 6: + printk("scsi%d: bus locked solid or invalid override\n", + instance->host_no); + } + } +} + +/* + * Function : int NCR5380_queue_command (Scsi_Cmnd *cmd, + * void (*done)(Scsi_Cmnd *)) + * + * Purpose : enqueues a SCSI command + * + * Inputs : cmd - SCSI command, done - function called on completion, with + * a pointer to the command descriptor. + * + * Returns : 0 + * + * Side effects : + * cmd is added to the per instance issue_queue, with minor + * twiddling done to the host specific fields of cmd. If the + * main coroutine is not running, it is restarted. + * + */ + +/* Only make static if a wrapper function is used */ +#ifndef NCR5380_queue_command +static +#endif +int NCR5380_queue_command (Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *)) { + struct Scsi_Host *instance = cmd->host; + struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) + instance->hostdata; + Scsi_Cmnd *tmp; + +#if (NDEBUG & NDEBUG_NO_WRITE) + switch (cmd->cmnd[0]) { + case WRITE_6: + case WRITE_10: + printk("scsi%d : WRITE attempted with NO_WRITE debugging flag set\n", + instance->host_no); + cmd->result = (DID_ERROR << 16); + done(cmd); + return 0; + } +#endif /* (NDEBUG & NDEBUG_NO_WRITE) */ + +#ifdef NCR5380_STATS +# if 0 + if (!hostdata->connected && !hostdata->issue_queue && + !hostdata->disconnected_queue) { + hostdata->timebase = jiffies; + } +# endif +# ifdef NCR5380_STAT_LIMIT + if (cmd->request_bufflen > NCR5380_STAT_LIMIT) +# endif + switch (cmd->cmnd[0]) + { + case WRITE: + case WRITE_6: + case WRITE_10: + hostdata->time_write[cmd->target] -= (jiffies - hostdata->timebase); + hostdata->bytes_write[cmd->target] += cmd->request_bufflen; + hostdata->pendingw++; + break; + case READ: + case READ_6: + case READ_10: + hostdata->time_read[cmd->target] -= (jiffies - hostdata->timebase); + hostdata->bytes_read[cmd->target] += cmd->request_bufflen; + hostdata->pendingr++; + break; + } +#endif + + /* + * We use the host_scribble field as a pointer to the next command + * in a queue + */ + + cmd->host_scribble = NULL; + cmd->scsi_done = done; + + cmd->result = 0; + + + /* + * Insert the cmd into the issue queue. Note that REQUEST SENSE + * commands are added to the head of the queue since any command will + * clear the contingent allegiance condition that exists and the + * sense data is only guaranteed to be valid while the condition exists. + */ + + cli(); + if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) { + LIST(cmd, hostdata->issue_queue); + cmd->host_scribble = (unsigned char *) hostdata->issue_queue; + hostdata->issue_queue = cmd; + } else { + for (tmp = (Scsi_Cmnd *) hostdata->issue_queue; tmp->host_scribble; + tmp = (Scsi_Cmnd *) tmp->host_scribble); + LIST(cmd, tmp); + tmp->host_scribble = (unsigned char *) cmd; + } +#if (NDEBUG & NDEBUG_QUEUES) + printk("scsi%d : command added to %s of queue\n", instance->host_no, + (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail"); +#endif + +/* Run the coroutine if it isn't already running. */ + run_main(); + return 0; +} + +/* + * Function : NCR5380_main (void) + * + * Purpose : NCR5380_main is a coroutine that runs as long as more work can + * be done on the NCR5380 host adapters in a system. Both + * NCR5380_queue_command() and NCR5380_intr() will try to start it + * in case it is not running. + * + * NOTE : NCR5380_main exits with interrupts *disabled*, the caller should + * reenable them. This prevents reentrancy and kernel stack overflow. + */ + +static void NCR5380_main (void) { + Scsi_Cmnd *tmp, *prev; + struct Scsi_Host *instance; + struct NCR5380_hostdata *hostdata; + int done; + + /* + * We run (with interrupts disabled) until we're sure that none of + * the host adapters have anything that can be done, at which point + * we set main_running to 0 and exit. + * + * Interrupts are enabled before doing various other internal + * instructions, after we've decided that we need to run through + * the loop again. + * + * this should prevent any race conditions. + */ + + do { + cli(); /* Freeze request queues */ + done = 1; + for (instance = first_instance; instance && + instance->hostt == the_template; instance=instance->next) { + hostdata = (struct NCR5380_hostdata *) instance->hostdata; + cli(); + if (!hostdata->connected) { +#if (NDEBUG & NDEBUG_MAIN) + printk("scsi%d : not connected\n", instance->host_no); +#endif + /* + * Search through the issue_queue for a command destined + * for a target that's not busy. + */ +#if (NDEBUG & NDEBUG_LISTS) + for (tmp= (Scsi_Cmnd *) hostdata->issue_queue, prev=NULL; tmp && (tmp != prev); prev=tmp, tmp=(Scsi_Cmnd*)tmp->host_scribble) + ; + /*printk("%p ", tmp);*/ + if ((tmp == prev) && tmp) printk(" LOOP\n");/* else printk("\n");*/ +#endif + for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, + prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) + tmp->host_scribble) { + +#if (NDEBUG & NDEBUG_LISTS) + if (prev != tmp) + printk("MAIN tmp=%p target=%d busy=%d lun=%d\n", tmp, tmp->target, hostdata->busy[tmp->target], tmp->lun); +#endif + /* When we find one, remove it from the issue queue. */ + if (!(hostdata->busy[tmp->target] & (1 << tmp->lun))) { + if (prev) { + REMOVE(prev,prev->host_scribble,tmp,tmp->host_scribble); + prev->host_scribble = tmp->host_scribble; + } else { + REMOVE(-1,hostdata->issue_queue,tmp,tmp->host_scribble); + hostdata->issue_queue = (Scsi_Cmnd *) tmp->host_scribble; + } + tmp->host_scribble = NULL; + + /* reenable interrupts after finding one */ + sti(); + + /* + * Attempt to establish an I_T_L nexus here. + * On success, instance->hostdata->connected is set. + * On failure, we must add the command back to the + * issue queue so we can keep trying. + */ +#if (NDEBUG & (NDEBUG_MAIN | NDEBUG_QUEUES)) + printk("scsi%d : main() : command for target %d lun %d removed from issue_queue\n", + instance->host_no, tmp->target, tmp->lun); +#endif + + /* + * A successful selection is defined as one that + * leaves us with the command connected and + * in hostdata->connected, OR has terminated the + * command. + * + * With successful commands, we fall through + * and see if we can do an information transfer, + * with failures we will restart. + */ + + if (!NCR5380_select(instance, tmp, + /* + * REQUEST SENSE commands are issued without tagged + * queueing, even on SCSI-II devices because the + * contingent allegiance condition exists for the + * entire unit. + */ + (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : + TAG_NEXT)) { + break; + } else { + cli(); + LIST(tmp, hostdata->issue_queue); + tmp->host_scribble = (unsigned char *) + hostdata->issue_queue; + hostdata->issue_queue = tmp; + done = 0; + sti(); +#if (NDEBUG & (NDEBUG_MAIN | NDEBUG_QUEUES)) + printk("scsi%d : main(): select() failed, returned to issue_queue\n", + instance->host_no); +#endif + } + } /* if target/lun is not busy */ + } /* for */ + } /* if (!hostdata->connected) */ + + if (hostdata->connected +#ifdef REAL_DMA + && !hostdata->dmalen +#endif +#ifdef USLEEP + && (!hostdata->time_expires || hostdata->time_expires >= jiffies) +#endif + ) { + sti(); +#if (NDEBUG & NDEBUG_MAIN) + printk("scsi%d : main() : performing information transfer\n", + instance->host_no); +#endif + NCR5380_information_transfer(instance); +#if (NDEBUG & NDEBUG_MAIN) + printk("scsi%d : main() : done set false\n", instance->host_no); +#endif + done = 0; + } else + break; + } /* for instance */ + } while (!done); + main_running = 0; +} + +#ifndef DONT_USE_INTR +/* + * Function : void NCR5380_intr (int irq) + * + * Purpose : handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses + * from the disconnected queue, and restarting NCR5380_main() + * as required. + * + * Inputs : int irq, irq that caused this interrupt. + * + */ + +static void NCR5380_intr (int irq, void *dev_id, struct pt_regs * regs) { + NCR5380_local_declare(); + struct Scsi_Host *instance; + int done; + unsigned char basr; +#if (NDEBUG & NDEBUG_INTR) + printk("scsi : NCR5380 irq %d triggered\n", irq); +#endif + do { + done = 1; + for (instance = first_instance; instance && (instance->hostt == + the_template); instance = instance->next) + if (instance->irq == irq) { + + /* Look for pending interrupts */ + NCR5380_setup(instance); + basr = NCR5380_read(BUS_AND_STATUS_REG); + /* XXX dispatch to appropriate routine if found and done=0 */ + if (basr & BASR_IRQ) { +#if (NDEBUG & NDEBUG_INTR) + NCR5380_print(instance); +#endif + if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == + (SR_SEL | SR_IO)) { + done = 0; + sti(); +#if (NDEBUG & NDEBUG_INTR) + printk("scsi%d : SEL interrupt\n", instance->host_no); +#endif + NCR5380_reselect(instance); + (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG); + } else if (basr & BASR_PARITY_ERROR) { +#if (NDEBUG & NDEBUG_INTR) + printk("scsi%d : PARITY interrupt\n", instance->host_no); +#endif + (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG); + } else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) { +#if (NDEBUG & NDEBUG_INTR) + printk("scsi%d : RESET interrupt\n", instance->host_no); +#endif + (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG); + } else { +/* + * XXX the rest of the interrupt conditions should *only* occur during a + * DMA transfer, which I haven't gotten around to fixing yet. + */ + +#if defined(REAL_DMA) + /* + * We should only get PHASE MISMATCH and EOP interrupts + * if we have DMA enabled, so do a sanity check based on + * the current setting of the MODE register. + */ + + if ((NCR5380_read(MODE_REG) & MR_DMA) && ((basr & + BASR_END_DMA_TRANSFER) || + !(basr & BASR_PHASE_MATCH))) { + int transfered; + + if (!hostdata->connected) + panic("scsi%d : received end of DMA interrupt with no connected cmd\n", + instance->hostno); + + transfered = (hostdata->dmalen - NCR5380_dma_residual(instance)); + hostdata->connected->SCp.this_residual -= transferred; + hostdata->connected->SCp.ptr += transferred; + hostdata->dmalen = 0; + + (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG); +#if NCR_TIMEOUT + { + unsigned long timeout = jiffies + NCR_TIMEOUT; + + while (NCR5380_read(BUS_AND_STATUS_REG) & BASR_ACK + && jiffies < timeout) + ; + if (jiffies >= timeout) + printk("scsi%d: timeout at NCR5380.c:%d\n", + host->host_no, __LINE__); + } +#else /* NCR_TIMEOUT */ + while (NCR5380_read(BUS_AND_STATUS_REG) & BASR_ACK); +#endif + + NCR5380_write(MODE_REG, MR_BASE); + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + } +#else +#if (NDEBUG & NDEBUG_INTR) + printk("scsi : unknown interrupt, BASR 0x%X, MR 0x%X, SR 0x%x\n", basr, NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG)); +#endif + (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG); +#endif + } + } /* if BASR_IRQ */ + if (!done) + run_main(); + } /* if (instance->irq == irq) */ + } while (!done); +} +#endif + +#ifdef NCR5380_STATS +static void collect_stats(struct NCR5380_hostdata* hostdata, Scsi_Cmnd* cmd) +{ +# ifdef NCR5380_STAT_LIMIT + if (cmd->request_bufflen > NCR5380_STAT_LIMIT) +# endif + switch (cmd->cmnd[0]) + { + case WRITE: + case WRITE_6: + case WRITE_10: + hostdata->time_write[cmd->target] += (jiffies - hostdata->timebase); + /*hostdata->bytes_write[cmd->target] += cmd->request_bufflen;*/ + hostdata->pendingw--; + break; + case READ: + case READ_6: + case READ_10: + hostdata->time_read[cmd->target] += (jiffies - hostdata->timebase); + /*hostdata->bytes_read[cmd->target] += cmd->request_bufflen;*/ + hostdata->pendingr--; + break; + } +} +#endif + +/* + * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd, + * int tag); + * + * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command, + * including ARBITRATION, SELECTION, and initial message out for + * IDENTIFY and queue messages. + * + * Inputs : instance - instantiation of the 5380 driver on which this + * target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for + * new tag, TAG_NONE for untagged queueing, otherwise set to the tag for + * the command that is presently connected. + * + * Returns : -1 if selection could not execute for some reason, + * 0 if selection succeeded or failed because the target + * did not respond. + * + * Side effects : + * If bus busy, arbitration failed, etc, NCR5380_select() will exit + * with registers as they should have been on entry - ie + * SELECT_ENABLE will be set appropriately, the NCR5380 + * will cease to drive any SCSI bus signals. + * + * If successful : I_T_L or I_T_L_Q nexus will be established, + * instance->connected will be set to cmd. + * SELECT interrupt will be disabled. + * + * If failed (no target) : cmd->scsi_done() will be called, and the + * cmd->result host byte set to DID_BAD_TARGET. + */ + +static int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd, + int tag) { + NCR5380_local_declare(); + struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata*) + instance->hostdata; + unsigned char tmp[3], phase; + unsigned char *data; + int len; + unsigned long timeout; + NCR5380_setup(instance); + + hostdata->restart_select = 0; +#if defined (NDEBUG) && (NDEBUG & NDEBUG_ARBITRATION) + NCR5380_print(instance); + printk("scsi%d : starting arbitration, id = %d\n", instance->host_no, + instance->this_id); +#endif + cli(); + + /* + * Set the phase bits to 0, otherwise the NCR5380 won't drive the + * data bus during SELECTION. + */ + + NCR5380_write(TARGET_COMMAND_REG, 0); + + + /* + * Start arbitration. + */ + + NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask); + NCR5380_write(MODE_REG, MR_ARBITRATE); + + sti(); + + /* Wait for arbitration logic to complete */ +#if NCR_TIMEOUT + { + unsigned long timeout = jiffies + 2*NCR_TIMEOUT; + + while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) + && jiffies < timeout) + ; + if (jiffies >= timeout) + { + printk("scsi: arbitration timeout at %d\n", __LINE__); + NCR5380_write(MODE_REG, MR_BASE); + NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); + return -1; + } + } +#else /* NCR_TIMEOUT */ + while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS)); +#endif + +#if (NDEBUG & NDEBUG_ARBITRATION) + printk("scsi%d : arbitration complete\n", instance->host_no); +/* Avoid GCC 2.4.5 asm needs to many reloads error */ + __asm__("nop"); +#endif + + /* + * The arbitration delay is 2.2us, but this is a minimum and there is + * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate + * the integral nature of udelay(). + * + */ + + udelay(3); + + /* Check for lost arbitration */ + if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) || + (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) || + (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) { + NCR5380_write(MODE_REG, MR_BASE); +#if (NDEBUG & NDEBUG_ARBITRATION) + printk("scsi%d : lost arbitration, deasserting MR_ARBITRATE\n", + instance->host_no); +#endif + return -1; + } + + + + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_SEL); + + if (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) { + NCR5380_write(MODE_REG, MR_BASE); + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); +#if (NDEBUG & NDEBUG_ARBITRATION) + printk("scsi%d : lost arbitration, deasserting ICR_ASSERT_SEL\n", + instance->host_no); +#endif + return -1; + } + + /* + * Again, bus clear + bus settle time is 1.2us, however, this is + * a minimum so we'll udelay ceil(1.2) + */ + + udelay(2); + +#if (NDEBUG & NDEBUG_ARBITRATION) + printk("scsi%d : won arbitration\n", instance->host_no); +#endif + + + /* + * Now that we have won arbitration, start Selection process, asserting + * the host and target ID's on the SCSI bus. + */ + + NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << cmd->target))); + + /* + * Raise ATN while SEL is true before BSY goes false from arbitration, + * since this is the only way to guarantee that we'll get a MESSAGE OUT + * phase immediately after selection. + */ + + NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY | + ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL )); + NCR5380_write(MODE_REG, MR_BASE); + + /* + * Reselect interrupts must be turned off prior to the dropping of BSY, + * otherwise we will trigger an interrupt. + */ + NCR5380_write(SELECT_ENABLE_REG, 0); + + /* + * The initiator shall then wait at least two deskew delays and release + * the BSY signal. + */ + udelay(1); /* wingel -- wait two bus deskew delay >2*45ns */ + + /* Reset BSY */ + NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA | + ICR_ASSERT_ATN | ICR_ASSERT_SEL)); + + /* + * Something weird happens when we cease to drive BSY - looks + * like the board/chip is letting us do another read before the + * appropriate propagation delay has expired, and we're confusing + * a BSY signal from ourselves as the target's response to SELECTION. + * + * A small delay (the 'C++' frontend breaks the pipeline with an + * unnecessary jump, making it work on my 386-33/Trantor T128, the + * tighter 'C' code breaks and requires this) solves the problem - + * the 1 us delay is arbitrary, and only used because this delay will + * be the same on other platforms and since it works here, it should + * work there. + * + * wingel suggests that this could be due to failing to wait + * one deskew delay. + */ + + udelay(1); + +#if (NDEBUG & NDEBUG_SELECTION) + printk("scsi%d : selecting target %d\n", instance->host_no, cmd->target); +#endif + + /* + * The SCSI specification calls for a 250 ms timeout for the actual + * selection. + */ + + timeout = jiffies + 250*HZ/1000; + + /* + * XXX very interesting - we're seeing a bounce where the BSY we + * asserted is being reflected / still asserted (propagation delay?) + * and it's detecting as true. Sigh. + */ + + while ((jiffies < timeout) && !(NCR5380_read(STATUS_REG) & + (SR_BSY | SR_IO))); + + if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == + (SR_SEL | SR_IO)) { + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + NCR5380_reselect(instance); + printk ("scsi%d : reselection after won arbitration?\n", + instance->host_no); + NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); + return -1; + } + + /* + * No less than two deskew delays after the initiator detects the + * BSY signal is true, it shall release the SEL signal and may + * change the DATA BUS. -wingel + */ + + udelay(1); + + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN); + + if (!(NCR5380_read(STATUS_REG) & SR_BSY)) { + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + if (hostdata->targets_present & (1 << cmd->target)) { + printk("scsi%d : weirdness\n", instance->host_no); + if (hostdata->restart_select) + printk("\trestart select\n"); +#ifdef NDEBUG + NCR5380_print (instance); +#endif + NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); + return -1; + } + cmd->result = DID_BAD_TARGET << 16; +#ifdef NCR5380_STATS + collect_stats(hostdata, cmd); +#endif + cmd->scsi_done(cmd); + NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); +#if (NDEBUG & NDEBUG_SELECTION) + printk("scsi%d : target did not respond within 250ms\n", + instance->host_no); +#endif + NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); + return 0; + } + + hostdata->targets_present |= (1 << cmd->target); + + /* + * Since we followed the SCSI spec, and raised ATN while SEL + * was true but before BSY was false during selection, the information + * transfer phase should be a MESSAGE OUT phase so that we can send the + * IDENTIFY message. + * + * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG + * message (2 bytes) with a tag ID that we increment with every command + * until it wraps back to 0. + * + * XXX - it turns out that there are some broken SCSI-II devices, + * which claim to support tagged queuing but fail when more than + * some number of commands are issued at once. + */ + + /* Wait for start of REQ/ACK handshake */ +#ifdef NCR_TIMEOUT + { + unsigned long timeout = jiffies + NCR_TIMEOUT; + + while (!(NCR5380_read(STATUS_REG) & SR_REQ) && jiffies < timeout); + + if (jiffies >= timeout) { + printk("scsi%d: timeout at NCR5380.c:%d\n", __LINE__); + NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); + return -1; + } + } +#else /* NCR_TIMEOUT */ + while (!(NCR5380_read(STATUS_REG) & SR_REQ)); +#endif /* def NCR_TIMEOUT */ + +#if (NDEBUG & NDEBUG_SELECTION) + printk("scsi%d : target %d selected, going into MESSAGE OUT phase.\n", + instance->host_no, cmd->target); +#endif + tmp[0] = IDENTIFY(((instance->irq == IRQ_NONE) ? 0 : 1), cmd->lun); +#ifdef SCSI2 + if (cmd->device->tagged_queue && (tag != TAG_NONE)) { + tmp[1] = SIMPLE_QUEUE_TAG; + if (tag == TAG_NEXT) { + /* 0 is TAG_NONE, used to imply no tag for this command */ + if (cmd->device->current_tag == 0) + cmd->device->current_tag = 1; + + cmd->tag = cmd->device->current_tag; + cmd->device->current_tag++; + } else + cmd->tag = (unsigned char) tag; + + tmp[2] = cmd->tag; + hostdata->last_message = SIMPLE_QUEUE_TAG; + len = 3; + } else +#endif /* def SCSI2 */ + { + len = 1; + cmd->tag=0; + } + + /* Send message(s) */ + data = tmp; + phase = PHASE_MSGOUT; + NCR5380_transfer_pio(instance, &phase, &len, &data); +#if (NDEBUG & NDEBUG_SELECTION) + printk("scsi%d : nexus established.\n", instance->host_no); +#endif + /* XXX need to handle errors here */ + hostdata->connected = cmd; +#ifdef SCSI2 + if (!cmd->device->tagged_queue) +#endif + hostdata->busy[cmd->target] |= (1 << cmd->lun); + + initialize_SCp(cmd); + + + return 0; +} + +/* + * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance, + * unsigned char *phase, int *count, unsigned char **data) + * + * Purpose : transfers data in given phase using polled I/O + * + * Inputs : instance - instance of driver, *phase - pointer to + * what phase is expected, *count - pointer to number of + * bytes to transfer, **data - pointer to data pointer. + * + * Returns : -1 when different phase is entered without transferring + * maximum number of bytes, 0 if all bytes or transfered or exit + * is in same phase. + * + * Also, *phase, *count, *data are modified in place. + * + * XXX Note : handling for bus free may be useful. + */ + +/* + * Note : this code is not as quick as it could be, however it + * IS 100% reliable, and for the actual data transfer where speed + * counts, we will always do a pseudo DMA or DMA transfer. + */ + +static int NCR5380_transfer_pio (struct Scsi_Host *instance, + unsigned char *phase, int *count, unsigned char **data) { + NCR5380_local_declare(); + register unsigned char p = *phase, tmp; + register int c = *count; + register unsigned char *d = *data; + NCR5380_setup(instance); + +#if (NDEBUG & NDEBUG_PIO) + if (!(p & SR_IO)) + printk("scsi%d : pio write %d bytes\n", instance->host_no, c); + else + printk("scsi%d : pio read %d bytes\n", instance->host_no, c); +#endif + + /* + * The NCR5380 chip will only drive the SCSI bus when the + * phase specified in the appropriate bits of the TARGET COMMAND + * REGISTER match the STATUS REGISTER + */ + + NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p)); + + do { + /* + * Wait for assertion of REQ, after which the phase bits will be + * valid + */ + while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ)); + +#if (NDEBUG & NDEBUG_HANDSHAKE) + printk("scsi%d : REQ detected\n", instance->host_no); +#endif + + /* Check for phase mismatch */ + if ((tmp & PHASE_MASK) != p) { +#if (NDEBUG & NDEBUG_PIO) + printk("scsi%d : phase mismatch\n", instance->host_no); + NCR5380_print_phase(instance); +#endif + break; + } + + /* Do actual transfer from SCSI bus to / from memory */ + if (!(p & SR_IO)) + NCR5380_write(OUTPUT_DATA_REG, *d); + else + *d = NCR5380_read(CURRENT_SCSI_DATA_REG); + + ++d; + + /* + * The SCSI standard suggests that in MSGOUT phase, the initiator + * should drop ATN on the last byte of the message phase + * after REQ has been asserted for the handshake but before + * the initiator raises ACK. + */ + + if (!(p & SR_IO)) { + if (!((p & SR_MSG) && c > 1)) { + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | + ICR_ASSERT_DATA); +#if (NDEBUG & NDEBUG_PIO) + NCR5380_print(instance); +#endif + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | + ICR_ASSERT_DATA | ICR_ASSERT_ACK); + } else { + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | + ICR_ASSERT_DATA | ICR_ASSERT_ATN); +#if (NDEBUG & NDEBUG_PIO) + NCR5380_print(instance); +#endif + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | + ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK); + } + } else { +#if (NDEBUG & NDEBUG_PIO) + NCR5380_print(instance); +#endif + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK); + } + + while (NCR5380_read(STATUS_REG) & SR_REQ); + +#if (NDEBUG & NDEBUG_HANDSHAKE) + printk("scsi%d : req false, handshake complete\n", instance->host_no); +#endif + +/* + * We have several special cases to consider during REQ/ACK handshaking : + * 1. We were in MSGOUT phase, and we are on the last byte of the + * message. ATN must be dropped as ACK is dropped. + * + * 2. We are in a MSGIN phase, and we are on the last byte of the + * message. We must exit with ACK asserted, so that the calling + * code may raise ATN before dropping ACK to reject the message. + * + * 3. ACK and ATN are clear and the target may proceed as normal. + */ + if (!(p == PHASE_MSGIN && c == 1)) { + if (p == PHASE_MSGOUT && c > 1) + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN); + else + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + } + } while (--c); + +#if (NDEBUG & NDEBUG_PIO) + printk("scsi%d : residual %d\n", instance->host_no, c); +#endif + + *count = c; + *data = d; + tmp = NCR5380_read(STATUS_REG); + if (tmp & SR_REQ) + *phase = tmp & PHASE_MASK; + else + *phase = PHASE_UNKNOWN; + + if (!c || (*phase == p)) + return 0; + else + return -1; +} + +static void do_reset (struct Scsi_Host *host) { + NCR5380_local_declare(); + NCR5380_setup(host); + + cli(); + NCR5380_write(TARGET_COMMAND_REG, + PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK)); + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST); + udelay(25); + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + sti(); +} + +/* + * Function : do_abort (Scsi_Host *host) + * + * Purpose : abort the currently established nexus. Should only be + * called from a routine which can drop into a + * + * Returns : 0 on success, -1 on failure. + */ + +static int do_abort (struct Scsi_Host *host) { + NCR5380_local_declare(); + unsigned char tmp, *msgptr, phase; + int len; + NCR5380_setup(host); + + + /* Request message out phase */ + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN); + + /* + * Wait for the target to indicate a valid phase by asserting + * REQ. Once this happens, we'll have either a MSGOUT phase + * and can immediately send the ABORT message, or we'll have some + * other phase and will have to source/sink data. + * + * We really don't care what value was on the bus or what value + * the target sees, so we just handshake. + */ + + while (!(tmp = NCR5380_read(STATUS_REG)) & SR_REQ); + + NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp)); + + if ((tmp & PHASE_MASK) != PHASE_MSGOUT) { + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | + ICR_ASSERT_ACK); + while (NCR5380_read(STATUS_REG) & SR_REQ); + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN); + } + + tmp = ABORT; + msgptr = &tmp; + len = 1; + phase = PHASE_MSGOUT; + NCR5380_transfer_pio (host, &phase, &len, &msgptr); + + /* + * If we got here, and the command completed successfully, + * we're about to go into bus free state. + */ + + return len ? -1 : 0; +} + +#if defined(REAL_DMA) || defined(PSEUDO_DMA) || defined (REAL_DMA_POLL) +/* + * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance, + * unsigned char *phase, int *count, unsigned char **data) + * + * Purpose : transfers data in given phase using either real + * or pseudo DMA. + * + * Inputs : instance - instance of driver, *phase - pointer to + * what phase is expected, *count - pointer to number of + * bytes to transfer, **data - pointer to data pointer. + * + * Returns : -1 when different phase is entered without transferring + * maximum number of bytes, 0 if all bytes or transfered or exit + * is in same phase. + * + * Also, *phase, *count, *data are modified in place. + * + */ + + +static int NCR5380_transfer_dma (struct Scsi_Host *instance, + unsigned char *phase, int *count, unsigned char **data) { + NCR5380_local_declare(); + register int c = *count; + register unsigned char p = *phase; + register unsigned char *d = *data; + unsigned char tmp; + int foo; +#if defined(REAL_DMA_POLL) + int cnt, toPIO; + unsigned char saved_data = 0, overrun = 0, residue; +#endif + + struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) + instance->hostdata; + + NCR5380_setup(instance); + + if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) { + *phase = tmp; + return -1; + } +#if defined(REAL_DMA) || defined(REAL_DMA_POLL) +#ifdef READ_OVERRUNS + if (p & SR_IO) { + c -= 2; + } +#endif +#if (NDEBUG & NDEBUG_DMA) + printk("scsi%d : initializing DMA channel %d for %s, %d bytes %s %0x\n", + instance->host_no, instance->dma_channel, (p & SR_IO) ? "reading" : + "writing", c, (p & SR_IO) ? "to" : "from", (unsigned) d); +#endif + hostdata->dma_len = (p & SR_IO) ? + NCR5380_dma_read_setup(instance, d, c) : + NCR5380_dma_write_setup(instance, d, c); +#endif + + NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p)); + +#ifdef REAL_DMA + NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY); +#elif defined(REAL_DMA_POLL) + NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE); +#else + /* + * Note : on my sample board, watch-dog timeouts occurred when interrupts + * were not disabled for the duration of a single DMA transfer, from + * before the setting of DMA mode to after transfer of the last byte. + */ + +#if defined(PSEUDO_DMA) && !defined(UNSAFE) + cli(); +#endif + /* KLL May need eop and parity in 53c400 */ + if (hostdata->flags & FLAG_NCR53C400) + NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_PAR_CHECK + | MR_ENABLE_PAR_INTR | MR_ENABLE_EOP_INTR | MR_DMA_MODE + | MR_MONITOR_BSY); + else + NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE); +#endif /* def REAL_DMA */ + +#if (NDEBUG & NDEBUG_DMA) & 0 + printk("scsi%d : mode reg = 0x%X\n", instance->host_no, NCR5380_read(MODE_REG)); +#endif + +/* + * FOO stuff. For some UNAPPARENT reason, I'm getting + * watchdog timers fired on bootup for NO APPARENT REASON, meaning it's + * probably a timing problem. + * + * Since this is the only place I have back-to-back writes, perhaps this + * is the problem? + */ + + if (p & SR_IO) { +#ifndef FOO + udelay(1); +#endif + NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0); + } else { +#ifndef FOO + udelay(1); +#endif + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA); +#ifndef FOO + udelay(1); +#endif + NCR5380_write(START_DMA_SEND_REG, 0); +#ifndef FOO + udelay(1); +#endif + } + +#if defined(REAL_DMA_POLL) + do { + tmp = NCR5380_read(BUS_AND_STATUS_REG); + } while ((tmp & BASR_PHASE_MATCH) && !(tmp & (BASR_BUSY_ERROR | + BASR_END_DMA_TRANSFER))); + +/* + At this point, either we've completed DMA, or we have a phase mismatch, + or we've unexpectedly lost BUSY (which is a real error). + + For write DMAs, we want to wait until the last byte has been + transferred out over the bus before we turn off DMA mode. Alas, there + seems to be no terribly good way of doing this on a 5380 under all + conditions. For non-scatter-gather operations, we can wait until REQ + and ACK both go false, or until a phase mismatch occurs. Gather-writes + are nastier, since the device will be expecting more data than we + are prepared to send it, and REQ will remain asserted. On a 53C8[01] we + could test LAST BIT SENT to assure transfer (I imagine this is precisely + why this signal was added to the newer chips) but on the older 538[01] + this signal does not exist. The workaround for this lack is a watchdog; + we bail out of the wait-loop after a modest amount of wait-time if + the usual exit conditions are not met. Not a terribly clean or + correct solution :-% + + Reads are equally tricky due to a nasty characteristic of the NCR5380. + If the chip is in DMA mode for an READ, it will respond to a target's + REQ by latching the SCSI data into the INPUT DATA register and asserting + ACK, even if it has _already_ been notified by the DMA controller that + the current DMA transfer has completed! If the NCR5380 is then taken + out of DMA mode, this already-acknowledged byte is lost. + + This is not a problem for "one DMA transfer per command" reads, because + the situation will never arise... either all of the data is DMA'ed + properly, or the target switches to MESSAGE IN phase to signal a + disconnection (either operation bringing the DMA to a clean halt). + However, in order to handle scatter-reads, we must work around the + problem. The chosen fix is to DMA N-2 bytes, then check for the + condition before taking the NCR5380 out of DMA mode. One or two extra + bytes are transferred via PIO as necessary to fill out the original + request. +*/ + + if (p & SR_IO) { +#ifdef READ_OVERRUNS + udelay(10); + if (((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH|BASR_ACK)) == + (BASR_PHASE_MATCH | BASR_ACK))) { + saved_data = NCR5380_read(INPUT_DATA_REGISTER); + overrun = 1; + } +#endif + } else { + int limit = 100; + while (((tmp = NCR5380_read(BUS_AND_STATUS_REG)) & BASR_ACK) || + (NCR5380_read(STATUS_REG) & SR_REQ)) { + if (!(tmp & BASR_PHASE_MATCH)) break; + if (--limit < 0) break; + } + } + + +#if (NDEBUG & NDEBUG_DMA) + printk("scsi%d : polled DMA transfer complete, basr 0x%X, sr 0x%X\n", + instance->host_no, tmp, NCR5380_read(STATUS_REG)); +#endif + + NCR5380_write(MODE_REG, MR_BASE); + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + + residue = NCR5380_dma_residual(instance); + c -= residue; + *count -= c; + *data += c; + *phase = NCR5380_read(STATUS_REG) & PHASE_MASK; + +#ifdef READ_OVERRUNS + if (*phase == p && (p & SR_IO) && residue == 0) { + if (overrun) { +#if (NDEBUG & NDEBUG_DMA) + printk("Got an input overrun, using saved byte\n"); +#endif + **data = saved_data; + *data += 1; + *count -= 1; + cnt = toPIO = 1; + } else { + printk("No overrun??\n"); + cnt = toPIO = 2; + } +#if (NDEBUG & NDEBUG_DMA) + printk("Doing %d-byte PIO to 0x%X\n", cnt, *data); +#endif + NCR5380_transfer_pio(instance, phase, &cnt, data); + *count -= toPIO - cnt; + } +#endif + +#if (NDEBUG & NDEBUG_DMA) + printk("Return with data ptr = 0x%X, count %d, last 0x%X, next 0x%X\n", + *data, *count, *(*data+*count-1), *(*data+*count)); +#endif + return 0; + +#elif defined(REAL_DMA) + return 0; +#else /* defined(REAL_DMA_POLL) */ + if (p & SR_IO) { +#ifdef DMA_WORKS_RIGHT + foo = NCR5380_pread(instance, d, c); +#else + int diff = 1; + if (hostdata->flags & FLAG_NCR53C400) { + diff=0; + } + + if (!(foo = NCR5380_pread(instance, d, c - diff))) { + /* + * We can't disable DMA mode after successfully transferring + * what we plan to be the last byte, since that would open up + * a race condition where if the target asserted REQ before + * we got the DMA mode reset, the NCR5380 would have latched + * an additional byte into the INPUT DATA register and we'd + * have dropped it. + * + * The workaround was to transfer one fewer bytes than we + * intended to with the pseudo-DMA read function, wait for + * the chip to latch the last byte, read it, and then disable + * pseudo-DMA mode. + * + * After REQ is asserted, the NCR5380 asserts DRQ and ACK. + * REQ is deasserted when ACK is asserted, and not reasserted + * until ACK goes false. Since the NCR5380 won't lower ACK + * until DACK is asserted, which won't happen unless we twiddle + * the DMA port or we take the NCR5380 out of DMA mode, we + * can guarantee that we won't handshake another extra + * byte. + */ + + if (!(hostdata->flags & FLAG_NCR53C400)) { + while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ)); + /* Wait for clean handshake */ + while (NCR5380_read(STATUS_REG) & SR_REQ); + d[c - 1] = NCR5380_read(INPUT_DATA_REG); + } + } +#endif + } else { +#ifdef DMA_WORKS_RIGHT + foo = NCR5380_pwrite(instance, d, c); +#else + int timeout; +#if (NDEBUG & NDEBUG_C400_PWRITE) + printk("About to pwrite %d bytes\n", c); +#endif + if (!(foo = NCR5380_pwrite(instance, d, c))) { + /* + * Wait for the last byte to be sent. If REQ is being asserted for + * the byte we're interested, we'll ACK it and it will go false. + */ + if (!(hostdata->flags & FLAG_HAS_LAST_BYTE_SENT)) { + timeout = 20000; +#if 1 +#if 1 + while (!(NCR5380_read(BUS_AND_STATUS_REG) & + BASR_DRQ) && (NCR5380_read(BUS_AND_STATUS_REG) & + BASR_PHASE_MATCH)); +#else + if (NCR5380_read(STATUS_REG) & SR_REQ) { + for (; timeout && + !(NCR5380_read(BUS_AND_STATUS_REG) & BASR_ACK); + --timeout); + for (; timeout && (NCR5380_read(STATUS_REG) & SR_REQ); + --timeout); + } +#endif + + +#if (NDEBUG & NDEBUG_LAST_BYTE_SENT) + if (!timeout) + printk("scsi%d : timed out on last byte\n", + instance->host_no); +#endif + + + if (hostdata->flags & FLAG_CHECK_LAST_BYTE_SENT) { + hostdata->flags &= ~FLAG_CHECK_LAST_BYTE_SENT; + if (NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT) { + hostdata->flags |= FLAG_HAS_LAST_BYTE_SENT; +#if (NDEBUG & NDEBUG_LAST_BYTE_SENT) + printk("scsi%d : last bit sent works\n", + instance->host_no); +#endif + } + } + } else { +#if (NDEBUG & NDEBUG_C400_PWRITE) + printk("Waiting for LASTBYTE\n"); +#endif + while (!(NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT)); +#if (NDEBUG & NDEBUG_C400_PWRITE) + printk("Got LASTBYTE\n"); +#endif + } +#else + udelay (5); +#endif + } +#endif + } + + NCR5380_write(MODE_REG, MR_BASE); + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + + if ((!(p & SR_IO)) && (hostdata->flags & FLAG_NCR53C400)) { +#if (NDEBUG & NDEBUG_C400_PWRITE) + printk("53C400w: Checking for IRQ\n"); +#endif + if (NCR5380_read(BUS_AND_STATUS_REG) & BASR_IRQ) { +#if (NDEBUG & NDEBUG_C400_PWRITE) + printk("53C400w: got it, reading reset interrupt reg\n"); +#endif + NCR5380_read(RESET_PARITY_INTERRUPT_REG); + } else { + printk("53C400w: IRQ NOT THERE!\n"); + } + } + + *data = d + c; + *count = 0; + *phase = NCR5380_read(STATUS_REG) & PHASE_MASK; +#if 0 + NCR5380_print_phase(instance); +#endif +#if defined(PSEUDO_DMA) && !defined(UNSAFE) + sti(); +#endif /* defined(REAL_DMA_POLL) */ + return foo; +#endif /* def REAL_DMA */ +} +#endif /* defined(REAL_DMA) | defined(PSEUDO_DMA) */ + +/* + * Function : NCR5380_information_transfer (struct Scsi_Host *instance) + * + * Purpose : run through the various SCSI phases and do as the target + * directs us to. Operates on the currently connected command, + * instance->connected. + * + * Inputs : instance, instance for which we are doing commands + * + * Side effects : SCSI things happen, the disconnected queue will be + * modified if a command disconnects, *instance->connected will + * change. + * + * XXX Note : we need to watch for bus free or a reset condition here + * to recover from an unexpected bus free condition. + */ + +static void NCR5380_information_transfer (struct Scsi_Host *instance) { + NCR5380_local_declare(); + struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) + instance->hostdata; + unsigned char msgout = NOP; + int sink = 0; + int len; +#if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL) + int transfersize; +#endif + unsigned char *data; + unsigned char phase, tmp, extended_msg[10], old_phase=0xff; + Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected; + NCR5380_setup(instance); + + while (1) { + tmp = NCR5380_read(STATUS_REG); + /* We only have a valid SCSI phase when REQ is asserted */ + if (tmp & SR_REQ) { + phase = (tmp & PHASE_MASK); + if (phase != old_phase) { + old_phase = phase; +#if (NDEBUG & NDEBUG_INFORMATION) + NCR5380_print_phase(instance); +#endif + } + + if (sink && (phase != PHASE_MSGOUT)) { + NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp)); + + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | + ICR_ASSERT_ACK); + while (NCR5380_read(STATUS_REG) & SR_REQ); + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | + ICR_ASSERT_ATN); + sink = 0; + continue; + } + + switch (phase) { + case PHASE_DATAIN: + case PHASE_DATAOUT: +#if (NDEBUG & NDEBUG_NO_DATAOUT) + printk("scsi%d : NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n", + instance->host_no); + sink = 1; + do_abort(instance); + cmd->result = DID_ERROR << 16; + cmd->done(cmd); + return; +#endif + /* + * If there is no room left in the current buffer in the + * scatter-gather list, move onto the next one. + */ + + if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) { + ++cmd->SCp.buffer; + --cmd->SCp.buffers_residual; + cmd->SCp.this_residual = cmd->SCp.buffer->length; + cmd->SCp.ptr = cmd->SCp.buffer->address; +#if (NDEBUG & NDEBUG_INFORMATION) + printk("scsi%d : %d bytes and %d buffers left\n", + instance->host_no, cmd->SCp.this_residual, + cmd->SCp.buffers_residual); +#endif + } + + /* + * The preferred transfer method is going to be + * PSEUDO-DMA for systems that are strictly PIO, + * since we can let the hardware do the handshaking. + * + * For this to work, we need to know the transfersize + * ahead of time, since the pseudo-DMA code will sit + * in an unconditional loop. + */ + +#if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL) + /* KLL + * PSEUDO_DMA is defined here. If this is the g_NCR5380 + * driver then it will always be defined, so the + * FLAG_NO_PSEUDO_DMA is used to inhibit PDMA in the base + * NCR5380 case. I think this is a fairly clean solution. + * We supplement these 2 if's with the flag. + */ +#ifdef NCR5380_dma_xfer_len + if (!cmd->device->borken && + !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && + (transfersize = NCR5380_dma_xfer_len(instance, cmd)) != 0) { +#else + transfersize = cmd->transfersize; + +#ifdef LIMIT_TRANSFERSIZE /* If we have problems with interrupt service */ + if( transfersize > 512 ) + transfersize = 512; +#endif /* LIMIT_TRANSFERSIZE */ + + if (!cmd->device->borken && transfersize && + !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && + cmd->SCp.this_residual && !(cmd->SCp.this_residual % + transfersize)) { + /* Limit transfers to 32K, for xx400 & xx406 + * pseudoDMA that transfers in 128 bytes blocks. */ + if (transfersize > 32*1024) + transfersize = 32*1024; +#endif + len = transfersize; + if (NCR5380_transfer_dma(instance, &phase, + &len, (unsigned char **) &cmd->SCp.ptr)) { + /* + * If the watchdog timer fires, all future accesses to this + * device will use the polled-IO. + */ + printk("scsi%d : switching target %d lun %d to slow handshake\n", + instance->host_no, cmd->target, cmd->lun); + cmd->device->borken = 1; + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | + ICR_ASSERT_ATN); + sink = 1; + do_abort(instance); + cmd->result = DID_ERROR << 16; + cmd->done(cmd); + /* XXX - need to source or sink data here, as appropriate */ + } else + cmd->SCp.this_residual -= transfersize - len; + } else +#endif /* defined(PSEUDO_DMA) || defined(REAL_DMA_POLL) */ + NCR5380_transfer_pio(instance, &phase, + (int *) &cmd->SCp.this_residual, (unsigned char **) + &cmd->SCp.ptr); + break; + case PHASE_MSGIN: + len = 1; + data = &tmp; + NCR5380_transfer_pio(instance, &phase, &len, &data); + cmd->SCp.Message = tmp; + + switch (tmp) { + /* + * Linking lets us reduce the time required to get the + * next command out to the device, hopefully this will + * mean we don't waste another revolution due to the delays + * required by ARBITRATION and another SELECTION. + * + * In the current implementation proposal, low level drivers + * merely have to start the next command, pointed to by + * next_link, done() is called as with unlinked commands. + */ +#ifdef LINKED + case LINKED_CMD_COMPLETE: + case LINKED_FLG_CMD_COMPLETE: + /* Accept message by clearing ACK */ + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + +#if (NDEBUG & NDEBUG_LINKED) + printk("scsi%d : target %d lun %d linked command complete.\n", + instance->host_no, cmd->target, cmd->lun); +#endif + /* + * Sanity check : A linked command should only terminate with + * one of these messages if there are more linked commands + * available. + */ + + if (!cmd->next_link) { + printk("scsi%d : target %d lun %d linked command complete, no next_link\n" + instance->host_no, cmd->target, cmd->lun); + sink = 1; + do_abort (instance); + return; + } + + initialize_SCp(cmd->next_link); + /* The next command is still part of this process */ + cmd->next_link->tag = cmd->tag; + cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8); +#if (NDEBUG & NDEBUG_LINKED) + printk("scsi%d : target %d lun %d linked request done, calling scsi_done().\n", + instance->host_no, cmd->target, cmd->lun); +#endif +#ifdef NCR5380_STATS + collect_stats(hostdata, cmd); +#endif + cmd->scsi_done(cmd); + cmd = hostdata->connected; + break; +#endif /* def LINKED */ + case ABORT: + case COMMAND_COMPLETE: + /* Accept message by clearing ACK */ + sink = 1; + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + hostdata->connected = NULL; +#if (NDEBUG & NDEBUG_QUEUES) + printk("scsi%d : command for target %d, lun %d completed\n", + instance->host_no, cmd->target, cmd->lun); +#endif + hostdata->busy[cmd->target] &= ~(1 << cmd->lun); + + /* + * I'm not sure what the correct thing to do here is : + * + * If the command that just executed is NOT a request + * sense, the obvious thing to do is to set the result + * code to the values of the stored parameters. + * + * If it was a REQUEST SENSE command, we need some way + * to differentiate between the failure code of the original + * and the failure code of the REQUEST sense - the obvious + * case is success, where we fall through and leave the result + * code unchanged. + * + * The non-obvious place is where the REQUEST SENSE failed + */ + + if (cmd->cmnd[0] != REQUEST_SENSE) + cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8); + else if (cmd->SCp.Status != GOOD) + cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16); + +#ifdef AUTOSENSE + if ((cmd->cmnd[0] != REQUEST_SENSE) && + (cmd->SCp.Status == CHECK_CONDITION)) { +#if (NDEBUG & NDEBUG_AUTOSENSE) + printk("scsi%d : performing request sense\n", + instance->host_no); +#endif + cmd->cmnd[0] = REQUEST_SENSE; + cmd->cmnd[1] &= 0xe0; + cmd->cmnd[2] = 0; + cmd->cmnd[3] = 0; + cmd->cmnd[4] = sizeof(cmd->sense_buffer); + cmd->cmnd[5] = 0; + + cmd->SCp.buffer = NULL; + cmd->SCp.buffers_residual = 0; + cmd->SCp.ptr = (char *) cmd->sense_buffer; + cmd->SCp.this_residual = sizeof(cmd->sense_buffer); + + cli(); + LIST(cmd,hostdata->issue_queue); + cmd->host_scribble = (unsigned char *) + hostdata->issue_queue; + hostdata->issue_queue = (Scsi_Cmnd *) cmd; + sti(); +#if (NDEBUG & NDEBUG_QUEUES) + printk("scsi%d : REQUEST SENSE added to head of issue queue\n",instance->host_no); +#endif + } else { +#endif /* def AUTOSENSE */ +#ifdef NCR5380_STATS + collect_stats(hostdata, cmd); +#endif + cmd->scsi_done(cmd); + } + + NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); + /* + * Restore phase bits to 0 so an interrupted selection, + * arbitration can resume. + */ + NCR5380_write(TARGET_COMMAND_REG, 0); + + while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected) + barrier(); + return; + case MESSAGE_REJECT: + /* Accept message by clearing ACK */ + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + switch (hostdata->last_message) { + case HEAD_OF_QUEUE_TAG: + case ORDERED_QUEUE_TAG: + case SIMPLE_QUEUE_TAG: + cmd->device->tagged_queue = 0; + hostdata->busy[cmd->target] |= (1 << cmd->lun); + break; + default: + break; + } + case DISCONNECT: + /* Accept message by clearing ACK */ + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + cmd->device->disconnect = 1; + cli(); + LIST(cmd,hostdata->disconnected_queue); + cmd->host_scribble = (unsigned char *) + hostdata->disconnected_queue; + hostdata->connected = NULL; + hostdata->disconnected_queue = cmd; + sti(); +#if (NDEBUG & NDEBUG_QUEUES) + printk("scsi%d : command for target %d lun %d was moved from connected to" + " the disconnected_queue\n", instance->host_no, + cmd->target, cmd->lun); +#endif + /* + * Restore phase bits to 0 so an interrupted selection, + * arbitration can resume. + */ + NCR5380_write(TARGET_COMMAND_REG, 0); + + /* Enable reselect interrupts */ + NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); + /* Wait for bus free to avoid nasty timeouts */ + while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected) + barrier(); +#if 0 + NCR5380_print_status(instance); +#endif + return; + /* + * The SCSI data pointer is *IMPLICITLY* saved on a disconnect + * operation, in violation of the SCSI spec so we can safely + * ignore SAVE/RESTORE pointers calls. + * + * Unfortunately, some disks violate the SCSI spec and + * don't issue the required SAVE_POINTERS message before + * disconnecting, and we have to break spec to remain + * compatible. + */ + case SAVE_POINTERS: + case RESTORE_POINTERS: + /* Accept message by clearing ACK */ + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + break; + case EXTENDED_MESSAGE: +/* + * Extended messages are sent in the following format : + * Byte + * 0 EXTENDED_MESSAGE == 1 + * 1 length (includes one byte for code, doesn't + * include first two bytes) + * 2 code + * 3..length+1 arguments + * + * Start the extended message buffer with the EXTENDED_MESSAGE + * byte, since print_msg() wants the whole thing. + */ + extended_msg[0] = EXTENDED_MESSAGE; + /* Accept first byte by clearing ACK */ + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + +#if (NDEBUG & NDEBUG_EXTENDED) + printk("scsi%d : receiving extended message\n", + instance->host_no); +#endif + + len = 2; + data = extended_msg + 1; + phase = PHASE_MSGIN; + NCR5380_transfer_pio(instance, &phase, &len, &data); + +#if (NDEBUG & NDEBUG_EXTENDED) + printk("scsi%d : length=%d, code=0x%02x\n", + instance->host_no, (int) extended_msg[1], + (int) extended_msg[2]); +#endif + + if (!len && extended_msg[1] <= + (sizeof (extended_msg) - 1)) { + /* Accept third byte by clearing ACK */ + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + len = extended_msg[1] - 1; + data = extended_msg + 3; + phase = PHASE_MSGIN; + + NCR5380_transfer_pio(instance, &phase, &len, &data); + +#if (NDEBUG & NDEBUG_EXTENDED) + printk("scsi%d : message received, residual %d\n", + instance->host_no, len); +#endif + + switch (extended_msg[2]) { + case EXTENDED_SDTR: + case EXTENDED_WDTR: + case EXTENDED_MODIFY_DATA_POINTER: + case EXTENDED_EXTENDED_IDENTIFY: + tmp = 0; + } + } else if (len) { + printk("scsi%d: error receiving extended message\n", + instance->host_no); + tmp = 0; + } else { + printk("scsi%d: extended message code %02x length %d is too long\n", + instance->host_no, extended_msg[2], extended_msg[1]); + tmp = 0; + } + /* Fall through to reject message */ + + /* + * If we get something weird that we aren't expecting, + * reject it. + */ + default: + if (!tmp) { + printk("scsi%d: rejecting message ", instance->host_no); + print_msg (extended_msg); + printk("\n"); + } else if (tmp != EXTENDED_MESSAGE) + printk("scsi%d: rejecting unknown message %02x from target %d, lun %d\n", + instance->host_no, tmp, cmd->target, cmd->lun); + else + printk("scsi%d: rejecting unknown extended message code %02x, length %d from target %d, lun %d\n", + instance->host_no, extended_msg[1], extended_msg[0], cmd->target, cmd->lun); + + msgout = MESSAGE_REJECT; + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | + ICR_ASSERT_ATN); + break; + } /* switch (tmp) */ + break; + case PHASE_MSGOUT: + len = 1; + data = &msgout; + hostdata->last_message = msgout; + NCR5380_transfer_pio(instance, &phase, &len, &data); + if (msgout == ABORT) { + hostdata->busy[cmd->target] &= ~(1 << cmd->lun); + hostdata->connected = NULL; + cmd->result = DID_ERROR << 16; +#ifdef NCR5380_STATS + collect_stats(hostdata, cmd); +#endif + cmd->scsi_done(cmd); + NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); + return; + } + msgout = NOP; + break; + case PHASE_CMDOUT: + len = cmd->cmd_len; + data = cmd->cmnd; + /* + * XXX for performance reasons, on machines with a + * PSEUDO-DMA architecture we should probably + * use the dma transfer function. + */ + NCR5380_transfer_pio(instance, &phase, &len, + &data); +#ifdef USLEEP + if (!disconnect && should_disconnect(cmd->cmnd[0])) { + hostdata->time_expires = jiffies + USLEEP_SLEEP; +#if (NDEBUG & NDEBUG_USLEEP) + printk("scsi%d : issued command, sleeping until %ul\n", instance->host_no, + hostdata->time_expires); +#endif + NCR5380_set_timer (instance); + return; + } +#endif /* def USLEEP */ + break; + case PHASE_STATIN: + len = 1; + data = &tmp; + NCR5380_transfer_pio(instance, &phase, &len, &data); + cmd->SCp.Status = tmp; + break; + default: + printk("scsi%d : unknown phase\n", instance->host_no); +#ifdef NDEBUG + NCR5380_print(instance); +#endif + } /* switch(phase) */ + } /* if (tmp * SR_REQ) */ +#ifdef USLEEP + else { + if (!disconnect && hostdata->time_expires && jiffies > + hostdata->time_expires) { + hostdata->time_expires = jiffies + USLEEP_SLEEP; +#if (NDEBUG & NDEBUG_USLEEP) + printk("scsi%d : poll timed out, sleeping until %ul\n", instance->host_no, + hostdata->time_expires); +#endif + NCR5380_set_timer (instance); + return; + } + } +#endif + } /* while (1) */ +} + +/* + * Function : void NCR5380_reselect (struct Scsi_Host *instance) + * + * Purpose : does reselection, initializing the instance->connected + * field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q + * nexus has been reestablished, + * + * Inputs : instance - this instance of the NCR5380. + * + */ + + +static void NCR5380_reselect (struct Scsi_Host *instance) { + NCR5380_local_declare(); + struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) + instance->hostdata; + unsigned char target_mask; + unsigned char lun, phase; + int len; +#ifdef SCSI2 + unsigned char tag; +#endif + unsigned char msg[3]; + unsigned char *data; + Scsi_Cmnd *tmp = NULL, *prev; + int abort = 0; + NCR5380_setup(instance); + + /* + * Disable arbitration, etc. since the host adapter obviously + * lost, and tell an interrupted NCR5380_select() to restart. + */ + + NCR5380_write(MODE_REG, MR_BASE); + hostdata->restart_select = 1; + + target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask); + +#if (NDEBUG & NDEBUG_RESELECTION) + printk("scsi%d : reselect\n", instance->host_no); +#endif + + /* + * At this point, we have detected that our SCSI ID is on the bus, + * SEL is true and BSY was false for at least one bus settle delay + * (400 ns). + * + * We must assert BSY ourselves, until the target drops the SEL + * signal. + */ + + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY); + + while (NCR5380_read(STATUS_REG) & SR_SEL); + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + + /* + * Wait for target to go into MSGIN. + */ + + while (!(NCR5380_read(STATUS_REG) & SR_REQ)); + + len = 1; + data = msg; + phase = PHASE_MSGIN; + NCR5380_transfer_pio(instance, &phase, &len, &data); + + + if (!msg[0] & 0x80) { + printk("scsi%d : expecting IDENTIFY message, got ", + instance->host_no); + print_msg(msg); + abort = 1; + } else { + /* Accept message by clearing ACK */ + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + lun = (msg[0] & 0x07); + + /* + * We need to add code for SCSI-II to track which devices have + * I_T_L_Q nexuses established, and which have simple I_T_L + * nexuses so we can chose to do additional data transfer. + */ + +#ifdef SCSI2 +#error "SCSI-II tagged queueing is not supported yet" +#endif + + /* + * Find the command corresponding to the I_T_L or I_T_L_Q nexus we + * just reestablished, and remove it from the disconnected queue. + */ + + + for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL; + tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble) + if ((target_mask == (1 << tmp->target)) && (lun == tmp->lun) +#ifdef SCSI2 + && (tag == tmp->tag) +#endif +) { + if (prev) { + REMOVE(prev,prev->host_scribble,tmp,tmp->host_scribble); + prev->host_scribble = tmp->host_scribble; + } else { + REMOVE(-1,hostdata->disconnected_queue,tmp,tmp->host_scribble); + hostdata->disconnected_queue = (Scsi_Cmnd *) tmp->host_scribble; + } + tmp->host_scribble = NULL; + break; + } + + if (!tmp) { +#ifdef SCSI2 + printk("scsi%d : warning : target bitmask %02x lun %d tag %d not in disconnect_queue.\n", + instance->host_no, target_mask, lun, tag); +#else + printk("scsi%d : warning : target bitmask %02x lun %d not in disconnect_queue.\n", + instance->host_no, target_mask, lun); +#endif + /* + * Since we have an established nexus that we can't do anything with, + * we must abort it. + */ + abort = 1; + } + } + + if (abort) { + do_abort (instance); + } else { + hostdata->connected = tmp; +#if (NDEBUG & NDEBUG_RESELECTION) + printk("scsi%d : nexus established, target = %d, lun = %d, tag = %d\n", + instance->host_no, tmp->target, tmp->lun, tmp->tag); +#endif + } +} + +/* + * Function : void NCR5380_dma_complete (struct Scsi_Host *instance) + * + * Purpose : called by interrupt handler when DMA finishes or a phase + * mismatch occurs (which would finish the DMA transfer). + * + * Inputs : instance - this instance of the NCR5380. + * + * Returns : pointer to the Scsi_Cmnd structure for which the I_T_L + * nexus has been reestablished, on failure NULL is returned. + */ + +#ifdef REAL_DMA +static void NCR5380_dma_complete (NCR5380_instance *instance) { + NCR5380_local_declare(); + struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata * + instance->hostdata); + int transferred; + NCR5380_setup(instance); + + /* + * XXX this might not be right. + * + * Wait for final byte to transfer, ie wait for ACK to go false. + * + * We should use the Last Byte Sent bit, unfortunately this is + * not available on the 5380/5381 (only the various CMOS chips) + */ + + while (NCR5380_read(BUS_AND_STATUS_REG) & BASR_ACK); + + NCR5380_write(MODE_REG, MR_BASE); + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + + /* + * The only places we should see a phase mismatch and have to send + * data from the same set of pointers will be the data transfer + * phases. So, residual, requested length are only important here. + */ + + if (!(hostdata->connected->SCp.phase & SR_CD)) { + transferred = instance->dmalen - NCR5380_dma_residual(); + hostdata->connected->SCp.this_residual -= transferred; + hostdata->connected->SCp.ptr += transferred; + } +} +#endif /* def REAL_DMA */ + +/* + * Function : int NCR5380_abort (Scsi_Cmnd *cmd) + * + * Purpose : abort a command + * + * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the + * host byte of the result field to, if zero DID_ABORTED is + * used. + * + * Returns : 0 - success, -1 on failure. + * + * XXX - there is no way to abort the command that is currently + * connected, you have to wait for it to complete. If this is + * a problem, we could implement longjmp() / setjmp(), setjmp() + * called where the loop started in NCR5380_main(). + */ + +#ifndef NCR5380_abort +static +#endif +int NCR5380_abort (Scsi_Cmnd *cmd) { + NCR5380_local_declare(); + struct Scsi_Host *instance = cmd->host; + struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) + instance->hostdata; + Scsi_Cmnd *tmp, **prev; + + printk("scsi%d : aborting command\n", instance->host_no); + print_Scsi_Cmnd (cmd); + + NCR5380_print_status (instance); + + printk("scsi%d : aborting command\n", instance->host_no); + print_Scsi_Cmnd (cmd); + + NCR5380_print_status (instance); + + cli(); + NCR5380_setup(instance); + +#if (NDEBUG & NDEBUG_ABORT) + printk("scsi%d : abort called\n", instance->host_no); + printk(" basr 0x%X, sr 0x%X\n", + NCR5380_read(BUS_AND_STATUS_REG), NCR5380_read(STATUS_REG)); +#endif + +#if 0 +/* + * Case 1 : If the command is the currently executing command, + * we'll set the aborted flag and return control so that + * information transfer routine can exit cleanly. + */ + + if (hostdata->connected == cmd) { +#if (NDEBUG & NDEBUG_ABORT) + printk("scsi%d : aborting connected command\n", instance->host_no); +#endif + hostdata->aborted = 1; +/* + * We should perform BSY checking, and make sure we haven't slipped + * into BUS FREE. + */ + + NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN); +/* + * Since we can't change phases until we've completed the current + * handshake, we have to source or sink a byte of data if the current + * phase is not MSGOUT. + */ + +/* + * Return control to the executing NCR drive so we can clear the + * aborted flag and get back into our main loop. + */ + + return 0; + } +#endif + +/* + * Case 2 : If the command hasn't been issued yet, we simply remove it + * from the issue queue. + */ +#if (NDEBUG & NDEBUG_ABORT) + /* KLL */ + printk("scsi%d : abort going into loop.\n", instance->host_no); +#endif + for (prev = (Scsi_Cmnd **) &(hostdata->issue_queue), + tmp = (Scsi_Cmnd *) hostdata->issue_queue; + tmp; prev = (Scsi_Cmnd **) &(tmp->host_scribble), tmp = + (Scsi_Cmnd *) tmp->host_scribble) + if (cmd == tmp) { + REMOVE(5,*prev,tmp,tmp->host_scribble); + (*prev) = (Scsi_Cmnd *) tmp->host_scribble; + tmp->host_scribble = NULL; + tmp->result = DID_ABORT << 16; + sti(); +#if (NDEBUG & NDEBUG_ABORT) + printk("scsi%d : abort removed command from issue queue.\n", + instance->host_no); +#endif + tmp->done(tmp); + return SCSI_ABORT_SUCCESS; + } +#if (NDEBUG & NDEBUG_ABORT) + /* KLL */ + else if (prev == tmp) printk("scsi%d : LOOP\n", instance->host_no); +#endif + +/* + * Case 3 : If any commands are connected, we're going to fail the abort + * and let the high level SCSI driver retry at a later time or + * issue a reset. + * + * Timeouts, and therefore aborted commands, will be highly unlikely + * and handling them cleanly in this situation would make the common + * case of noresets less efficient, and would pollute our code. So, + * we fail. + */ + + if (hostdata->connected) { + sti(); +#if (NDEBUG & NDEBUG_ABORT) + printk("scsi%d : abort failed, command connected.\n", instance->host_no); +#endif + return SCSI_ABORT_NOT_RUNNING; + } + +/* + * Case 4: If the command is currently disconnected from the bus, and + * there are no connected commands, we reconnect the I_T_L or + * I_T_L_Q nexus associated with it, go into message out, and send + * an abort message. + * + * This case is especially ugly. In order to reestablish the nexus, we + * need to call NCR5380_select(). The easiest way to implement this + * function was to abort if the bus was busy, and let the interrupt + * handler triggered on the SEL for reselect take care of lost arbitrations + * where necessary, meaning interrupts need to be enabled. + * + * When interrupts are enabled, the queues may change - so we + * can't remove it from the disconnected queue before selecting it + * because that could cause a failure in hashing the nexus if that + * device reselected. + * + * Since the queues may change, we can't use the pointers from when we + * first locate it. + * + * So, we must first locate the command, and if NCR5380_select() + * succeeds, then issue the abort, relocate the command and remove + * it from the disconnected queue. + */ + + for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp; + tmp = (Scsi_Cmnd *) tmp->host_scribble) + if (cmd == tmp) { + sti(); +#if (NDEBUG & NDEBUG_ABORT) + printk("scsi%d : aborting disconnected command.\n", instance->host_no); +#endif + + if (NCR5380_select (instance, cmd, (int) cmd->tag)) + return SCSI_ABORT_BUSY; + +#if (NDEBUG & NDEBUG_ABORT) + printk("scsi%d : nexus reestablished.\n", instance->host_no); +#endif + + do_abort (instance); + + cli(); + for (prev = (Scsi_Cmnd **) &(hostdata->disconnected_queue), + tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; + tmp; prev = (Scsi_Cmnd **) &(tmp->host_scribble), tmp = + (Scsi_Cmnd *) tmp->host_scribble) + if (cmd == tmp) { + REMOVE(5,*prev,tmp,tmp->host_scribble); + *prev = (Scsi_Cmnd *) tmp->host_scribble; + tmp->host_scribble = NULL; + tmp->result = DID_ABORT << 16; + sti(); + tmp->done(tmp); + return SCSI_ABORT_SUCCESS; + } + } + +/* + * Case 5 : If we reached this point, the command was not found in any of + * the queues. + * + * We probably reached this point because of an unlikely race condition + * between the command completing successfully and the abortion code, + * so we won't panic, but we will notify the user in case something really + * broke. + */ + + sti(); + printk("scsi%d : warning : SCSI command probably completed successfully\n" + " before abortion\n", instance->host_no); + return SCSI_ABORT_NOT_RUNNING; +} + + +/* + * Function : int NCR5380_reset (Scsi_Cmnd *cmd, unsigned int reset_flags) + * + * Purpose : reset the SCSI bus. + * + * Returns : SCSI_RESET_WAKEUP + * + */ + +#ifndef NCR5380_reset +static +#endif +int NCR5380_reset (Scsi_Cmnd *cmd, unsigned int dummy) { + NCR5380_local_declare(); + NCR5380_setup(cmd->host); + + NCR5380_print_status (cmd->host); + do_reset (cmd->host); + + return SCSI_RESET_WAKEUP; +} + |