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Diffstat (limited to 'linux/src/drivers/scsi/hosts.h')
| -rw-r--r-- | linux/src/drivers/scsi/hosts.h | 405 |
1 files changed, 405 insertions, 0 deletions
diff --git a/linux/src/drivers/scsi/hosts.h b/linux/src/drivers/scsi/hosts.h new file mode 100644 index 0000000..8f3f4e0 --- /dev/null +++ b/linux/src/drivers/scsi/hosts.h @@ -0,0 +1,405 @@ +/* + * hosts.h Copyright (C) 1992 Drew Eckhardt + * Copyright (C) 1993, 1994, 1995 Eric Youngdale + * + * mid to low-level SCSI driver interface header + * Initial versions: Drew Eckhardt + * Subsequent revisions: Eric Youngdale + * + * <drew@colorado.edu> + * + * Modified by Eric Youngdale eric@aib.com to + * add scatter-gather, multiple outstanding request, and other + * enhancements. + * + * Further modified by Eric Youngdale to support multiple host adapters + * of the same type. + */ + +#ifndef _HOSTS_H +#define _HOSTS_H + +/* + $Header: cvs/gnumach/linux/src/drivers/scsi/Attic/hosts.h,v 1.1 1999/04/26 05:54:41 tb Exp $ +*/ + +#include <linux/proc_fs.h> + +/* It is senseless to set SG_ALL any higher than this - the performance + * does not get any better, and it wastes memory + */ +#define SG_NONE 0 +#define SG_ALL 0xff + +#define DISABLE_CLUSTERING 0 +#define ENABLE_CLUSTERING 1 + +/* The various choices mean: + * NONE: Self evident. Host adapter is not capable of scatter-gather. + * ALL: Means that the host adapter module can do scatter-gather, + * and that there is no limit to the size of the table to which + * we scatter/gather data. + * Anything else: Indicates the maximum number of chains that can be + * used in one scatter-gather request. + */ + +/* + * The Scsi_Host_Template type has all that is needed to interface with a SCSI + * host in a device independent matter. There is one entry for each different + * type of host adapter that is supported on the system. + */ + +typedef struct scsi_disk Disk; + +typedef struct SHT +{ + + /* Used with loadable modules so we can construct a linked list. */ + struct SHT * next; + + /* Used with loadable modules so that we know when it is safe to unload */ + long * usage_count; + + /* The pointer to the /proc/scsi directory entry */ + struct proc_dir_entry *proc_dir; + + /* proc-fs info function. + * Can be used to export driver statistics and other infos to the world + * outside the kernel ie. userspace and it also provides an interface + * to feed the driver with information. Check eata_dma_proc.c for reference + */ + int (*proc_info)(char *, char **, off_t, int, int, int); + + /* + * The name pointer is a pointer to the name of the SCSI + * device detected. + */ + const char *name; + + /* + * The detect function shall return non zero on detection, + * indicating the number of host adapters of this particular + * type were found. It should also + * initialize all data necessary for this particular + * SCSI driver. It is passed the host number, so this host + * knows where the first entry is in the scsi_hosts[] array. + * + * Note that the detect routine MUST not call any of the mid level + * functions to queue commands because things are not guaranteed + * to be set up yet. The detect routine can send commands to + * the host adapter as long as the program control will not be + * passed to scsi.c in the processing of the command. Note + * especially that scsi_malloc/scsi_free must not be called. + */ + int (* detect)(struct SHT *); + + /* Used with loadable modules to unload the host structures. Note: + * there is a default action built into the modules code which may + * be sufficient for most host adapters. Thus you may not have to supply + * this at all. + */ + int (*release)(struct Scsi_Host *); + + /* + * The info function will return whatever useful + * information the developer sees fit. If not provided, then + * the name field will be used instead. + */ + const char *(* info)(struct Scsi_Host *); + + /* + * The command function takes a target, a command (this is a SCSI + * command formatted as per the SCSI spec, nothing strange), a + * data buffer pointer, and data buffer length pointer. The return + * is a status int, bit fielded as follows : + * Byte What + * 0 SCSI status code + * 1 SCSI 1 byte message + * 2 host error return. + * 3 mid level error return + */ + int (* command)(Scsi_Cmnd *); + + /* + * The QueueCommand function works in a similar manner + * to the command function. It takes an additional parameter, + * void (* done)(int host, int code) which is passed the host + * # and exit result when the command is complete. + * Host number is the POSITION IN THE hosts array of THIS + * host adapter. + */ + int (* queuecommand)(Scsi_Cmnd *, void (*done)(Scsi_Cmnd *)); + + /* + * Since the mid level driver handles time outs, etc, we want to + * be able to abort the current command. Abort returns 0 if the + * abortion was successful. The field SCpnt->abort reason + * can be filled in with the appropriate reason why we wanted + * the abort in the first place, and this will be used + * in the mid-level code instead of the host_byte(). + * If non-zero, the code passed to it + * will be used as the return code, otherwise + * DID_ABORT should be returned. + * + * Note that the scsi driver should "clean up" after itself, + * resetting the bus, etc. if necessary. + */ + int (* abort)(Scsi_Cmnd *); + + /* + * The reset function will reset the SCSI bus. Any executing + * commands should fail with a DID_RESET in the host byte. + * The Scsi_Cmnd is passed so that the reset routine can figure + * out which host adapter should be reset, and also which command + * within the command block was responsible for the reset in + * the first place. Some hosts do not implement a reset function, + * and these hosts must call scsi_request_sense(SCpnt) to keep + * the command alive. + */ + int (* reset)(Scsi_Cmnd *, unsigned int); + + /* + * This function is used to select synchronous communications, + * which will result in a higher data throughput. Not implemented + * yet. + */ + int (* slave_attach)(int, int); + + /* + * This function determines the bios parameters for a given + * harddisk. These tend to be numbers that are made up by + * the host adapter. Parameters: + * size, device number, list (heads, sectors, cylinders) + */ + int (* bios_param)(Disk *, kdev_t, int []); + + /* + * This determines if we will use a non-interrupt driven + * or an interrupt driven scheme, It is set to the maximum number + * of simultaneous commands a given host adapter will accept. + */ + int can_queue; + + /* + * In many instances, especially where disconnect / reconnect are + * supported, our host also has an ID on the SCSI bus. If this is + * the case, then it must be reserved. Please set this_id to -1 if + * your setup is in single initiator mode, and the host lacks an + * ID. + */ + int this_id; + + /* + * This determines the degree to which the host adapter is capable + * of scatter-gather. + */ + short unsigned int sg_tablesize; + + /* + * True if this host adapter can make good use of linked commands. + * This will allow more than one command to be queued to a given + * unit on a given host. Set this to the maximum number of command + * blocks to be provided for each device. Set this to 1 for one + * command block per lun, 2 for two, etc. Do not set this to 0. + * You should make sure that the host adapter will do the right thing + * before you try setting this above 1. + */ + short cmd_per_lun; + + /* + * present contains counter indicating how many boards of this + * type were found when we did the scan. + */ + unsigned char present; + + /* + * true if this host adapter uses unchecked DMA onto an ISA bus. + */ + unsigned unchecked_isa_dma:1; + + /* + * true if this host adapter can make good use of clustering. + * I originally thought that if the tablesize was large that it + * was a waste of CPU cycles to prepare a cluster list, but + * it works out that the Buslogic is faster if you use a smaller + * number of segments (i.e. use clustering). I guess it is + * inefficient. + */ + unsigned use_clustering:1; + +} Scsi_Host_Template; + +/* + * The scsi_hosts array is the array containing the data for all + * possible <supported> scsi hosts. This is similar to the + * Scsi_Host_Template, except that we have one entry for each + * actual physical host adapter on the system, stored as a linked + * list. Note that if there are 2 aha1542 boards, then there will + * be two Scsi_Host entries, but only 1 Scsi_Host_Template entry. + */ + +struct Scsi_Host +{ + struct Scsi_Host * next; + unsigned short extra_bytes; + volatile unsigned char host_busy; + char host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */ + unsigned long last_reset; + struct wait_queue *host_wait; + Scsi_Cmnd *host_queue; + Scsi_Host_Template * hostt; + + /* + * These three parameters can be used to allow for wide scsi, + * and for host adapters that support multiple busses + * The first two should be set to 1 more than the actual max id + * or lun (i.e. 8 for normal systems). + */ + unsigned int max_id; + unsigned int max_lun; + unsigned int max_channel; + + /* + * Pointer to a circularly linked list - this indicates the hosts + * that should be locked out of performing I/O while we have an active + * command on this host. + */ + struct Scsi_Host * block; + unsigned wish_block:1; + + /* These parameters should be set by the detect routine */ + unsigned char *base; + unsigned int io_port; + unsigned char n_io_port; + unsigned char irq; + unsigned char dma_channel; + + /* + * This is a unique identifier that must be assigned so that we + * have some way of identifying each detected host adapter properly + * and uniquely. For hosts that do not support more than one card + * in the system at one time, this does not need to be set. It is + * initialized to 0 in scsi_register. + */ + unsigned int unique_id; + + /* + * The rest can be copied from the template, or specifically + * initialized, as required. + */ + + int this_id; + int can_queue; + short cmd_per_lun; + short unsigned int sg_tablesize; + unsigned unchecked_isa_dma:1; + unsigned use_clustering:1; + /* + * True if this host was loaded as a loadable module + */ + unsigned loaded_as_module:1; + + void (*select_queue_depths)(struct Scsi_Host *, Scsi_Device *); + + unsigned long hostdata[0]; /* Used for storage of host specific stuff */ +}; + +extern struct Scsi_Host * scsi_hostlist; +extern struct Scsi_Device_Template * scsi_devicelist; + +extern Scsi_Host_Template * scsi_hosts; + +extern void build_proc_dir_entries(Scsi_Host_Template *); + + +/* + * scsi_init initializes the scsi hosts. + */ + +/* + * We use these goofy things because the MM is not set up when we init + * the scsi subsystem. By using these functions we can write code that + * looks normal. Also, it makes it possible to use the same code for a + * loadable module. + */ + +extern void * scsi_init_malloc(unsigned int size, int priority); +extern void scsi_init_free(char * ptr, unsigned int size); + +extern int next_scsi_host; + +extern int scsi_loadable_module_flag; +unsigned int scsi_init(void); +extern struct Scsi_Host * scsi_register(Scsi_Host_Template *, int j); +extern void scsi_unregister(struct Scsi_Host * i); + +#define BLANK_HOST {"", 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} + +struct Scsi_Device_Template +{ + struct Scsi_Device_Template * next; + const char * name; + const char * tag; + long * usage_count; /* Used for loadable modules */ + unsigned char scsi_type; + unsigned char major; + unsigned char nr_dev; /* Number currently attached */ + unsigned char dev_noticed; /* Number of devices detected. */ + unsigned char dev_max; /* Current size of arrays */ + unsigned blk:1; /* 0 if character device */ + int (*detect)(Scsi_Device *); /* Returns 1 if we can attach this device */ + int (*init)(void); /* Sizes arrays based upon number of devices + * detected */ + void (*finish)(void); /* Perform initialization after attachment */ + int (*attach)(Scsi_Device *); /* Attach devices to arrays */ + void (*detach)(Scsi_Device *); +}; + +extern struct Scsi_Device_Template sd_template; +extern struct Scsi_Device_Template st_template; +extern struct Scsi_Device_Template sr_template; +extern struct Scsi_Device_Template sg_template; + +int scsi_register_device(struct Scsi_Device_Template * sdpnt); + +/* These are used by loadable modules */ +extern int scsi_register_module(int, void *); +extern void scsi_unregister_module(int, void *); + +/* The different types of modules that we can load and unload */ +#define MODULE_SCSI_HA 1 +#define MODULE_SCSI_CONST 2 +#define MODULE_SCSI_IOCTL 3 +#define MODULE_SCSI_DEV 4 + + +/* + * This is an ugly hack. If we expect to be able to load devices at run time, + * we need to leave extra room in some of the data structures. Doing a + * realloc to enlarge the structures would be riddled with race conditions, + * so until a better solution is discovered, we use this crude approach + */ +#define SD_EXTRA_DEVS 2 +#define ST_EXTRA_DEVS 2 +#define SR_EXTRA_DEVS 2 +#define SG_EXTRA_DEVS (SD_EXTRA_DEVS + SR_EXTRA_DEVS + ST_EXTRA_DEVS) + +#endif +/* + * Overrides for Emacs so that we follow Linus's tabbing style. + * Emacs will notice this stuff at the end of the file and automatically + * adjust the settings for this buffer only. This must remain at the end + * of the file. + * --------------------------------------------------------------------------- + * Local variables: + * c-indent-level: 4 + * c-brace-imaginary-offset: 0 + * c-brace-offset: -4 + * c-argdecl-indent: 4 + * c-label-offset: -4 + * c-continued-statement-offset: 4 + * c-continued-brace-offset: 0 + * indent-tabs-mode: nil + * tab-width: 8 + * End: + */ |