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authorThomas Bushnell <thomas@gnu.org>1999-04-26 05:58:44 +0000
committerThomas Bushnell <thomas@gnu.org>1999-04-26 05:58:44 +0000
commit86297c41a26f18d924e64fc93321c59cbc4c48dd (patch)
tree376954c6b95b735d361875319a1a2a9db6a27527 /linux/src/drivers/scsi/scsicam.c
parent851137902d3e7ad87af177487df3eea53e940a1c (diff)
1998-11-30 OKUJI Yoshinori <okuji@kuicr.kyoto-u.ac.jp>
Clean up linux emulation code to make it architecture-independent as much as possible. * linux: Renamed from linuxdev. * Makefile.in (objfiles): Add linux.o instead of linuxdev.o. (MAKE): New variable. Used for the linux.o target. * configure.in: Add AC_CHECK_TOOL(MAKE, make). * i386/i386/spl.h: Include <i386/ipl.h>, for compatibility with OSF Mach 3.0. Suggested by Elgin Lee <ehl@funghi.com>. * linux/src: Renamed from linux/linux. * linux/dev: Renamed from linux/mach. * linux/Drivers.in (AC_INIT): Use dev/include/linux/autoconf.h, instead of mach/include/linux/autoconf.h. * Makefile.in (all): Target ../linux.o instead of ../linuxdev.o. * linux/dev/drivers/block/genhd.c: Include <machine/spl.h> instead of <i386/ipl.h>. * linux/dev/drivers/net/auto_irq.c: Remove unneeded header files, <i386/ipl.h> and <i386/pic.h>. * linux/dev/init/main.c: Many i386-dependent codes moved to ... * linux/dev/arch/i386/irq.c: ... here. * linux/dev/arch/i386/setup.c: New file. * linux/dev/arch/i386/linux_emul.h: Likewise. * linux/dev/arch/i386/glue/timer.c: Merged into sched.c. * linux/dev/arch/i386/glue/sched.c: Include <machine/spl.h> instead of <i386/ipl.h>, and moved to ... * linux/dev/kernel/sched.c: ... here. * linux/dev/arch/i386/glue/block.c: Include <machine/spl.h> and <linux_emul.h>, instead of i386-dependent header files, and moved to ... * linux/dev/glue/blocl.c: ... here. * linux/dev/arch/i386/glue/net.c: Include <machine/spl.h> and <linux_emul.h>, instead of i386-dependent header files, and moved to ... * linux/dev/glue/net.c: ... here. * linux/dev/arch/i386/glue/misc.c: Remove `x86' and moved to ... * linux/dev/glue/misc.c: ... here. * linux/dev/arch/i386/glue/kmem.c: Moved to ... * linux/dev/glue/kmem.c: ... here.
Diffstat (limited to 'linux/src/drivers/scsi/scsicam.c')
-rw-r--r--linux/src/drivers/scsi/scsicam.c230
1 files changed, 230 insertions, 0 deletions
diff --git a/linux/src/drivers/scsi/scsicam.c b/linux/src/drivers/scsi/scsicam.c
new file mode 100644
index 0000000..2c6f637
--- /dev/null
+++ b/linux/src/drivers/scsi/scsicam.c
@@ -0,0 +1,230 @@
+/*
+ * scsicam.c - SCSI CAM support functions, use for HDIO_GETGEO, etc.
+ *
+ * Copyright 1993, 1994 Drew Eckhardt
+ * Visionary Computing
+ * (Unix and Linux consulting and custom programming)
+ * drew@Colorado.EDU
+ * +1 (303) 786-7975
+ *
+ * For more information, please consult the SCSI-CAM draft.
+ */
+
+/*
+ * Don't import our own symbols, as this would severely mess up our
+ * symbol tables.
+ */
+#define _SCSI_SYMS_VER_
+#define __NO_VERSION__
+#include <linux/module.h>
+
+#include <linux/fs.h>
+#include <linux/genhd.h>
+#include <linux/kernel.h>
+#include <linux/blk.h>
+#include <asm/unaligned.h>
+#include "scsi.h"
+#include "hosts.h"
+#include "sd.h"
+
+static int partsize(struct buffer_head *bh, unsigned long capacity,
+ unsigned int *cyls, unsigned int *hds, unsigned int *secs);
+static int setsize(unsigned long capacity,unsigned int *cyls,unsigned int *hds,
+ unsigned int *secs);
+
+/*
+ * Function : int scsicam_bios_param (Disk *disk, int dev, int *ip)
+ *
+ * Purpose : to determine the BIOS mapping used for a drive in a
+ * SCSI-CAM system, storing the results in ip as required
+ * by the HDIO_GETGEO ioctl().
+ *
+ * Returns : -1 on failure, 0 on success.
+ *
+ */
+
+int scsicam_bios_param (Disk *disk, /* SCSI disk */
+ kdev_t dev, /* Device major, minor */
+ int *ip /* Heads, sectors, cylinders in that order */) {
+
+ struct buffer_head *bh;
+ int ret_code;
+ int size = disk->capacity;
+ unsigned long temp_cyl;
+
+ if (!(bh = bread(MKDEV(MAJOR(dev), MINOR(dev)&~0xf), 0, 1024)))
+ return -1;
+
+ /* try to infer mapping from partition table */
+ ret_code = partsize (bh, (unsigned long) size, (unsigned int *) ip + 2,
+ (unsigned int *) ip + 0, (unsigned int *) ip + 1);
+ brelse (bh);
+
+ if (ret_code == -1) {
+ /* pick some standard mapping with at most 1024 cylinders,
+ and at most 62 sectors per track - this works up to
+ 7905 MB */
+ ret_code = setsize ((unsigned long) size, (unsigned int *) ip + 2,
+ (unsigned int *) ip + 0, (unsigned int *) ip + 1);
+ }
+
+ /* if something went wrong, then apparently we have to return
+ a geometry with more than 1024 cylinders */
+ if (ret_code || ip[0] > 255 || ip[1] > 63) {
+ ip[0] = 64;
+ ip[1] = 32;
+ temp_cyl = size / (ip[0] * ip[1]);
+ if (temp_cyl > 65534) {
+ ip[0] = 255;
+ ip[1] = 63;
+ }
+ ip[2] = size / (ip[0] * ip[1]);
+ }
+
+ return 0;
+}
+
+/*
+ * Function : static int partsize(struct buffer_head *bh, unsigned long
+ * capacity,unsigned int *cyls, unsigned int *hds, unsigned int *secs);
+ *
+ * Purpose : to determine the BIOS mapping used to create the partition
+ * table, storing the results in *cyls, *hds, and *secs
+ *
+ * Returns : -1 on failure, 0 on success.
+ *
+ */
+
+static int partsize(struct buffer_head *bh, unsigned long capacity,
+ unsigned int *cyls, unsigned int *hds, unsigned int *secs) {
+ struct partition *p, *largest = NULL;
+ int i, largest_cyl;
+ int cyl, ext_cyl, end_head, end_cyl, end_sector;
+ unsigned int logical_end, physical_end, ext_physical_end;
+
+
+ if (*(unsigned short *) (bh->b_data+510) == 0xAA55) {
+ for (largest_cyl = -1, p = (struct partition *)
+ (0x1BE + bh->b_data), i = 0; i < 4; ++i, ++p) {
+ if (!p->sys_ind)
+ continue;
+#ifdef DEBUG
+ printk ("scsicam_bios_param : partition %d has system \n",
+ i);
+#endif
+ cyl = p->cyl + ((p->sector & 0xc0) << 2);
+ if (cyl > largest_cyl) {
+ largest_cyl = cyl;
+ largest = p;
+ }
+ }
+ }
+
+ if (largest) {
+ end_cyl = largest->end_cyl + ((largest->end_sector & 0xc0) << 2);
+ end_head = largest->end_head;
+ end_sector = largest->end_sector & 0x3f;
+
+ if( end_head + 1 == 0 || end_sector == 0 ) return -1;
+
+#ifdef DEBUG
+ printk ("scsicam_bios_param : end at h = %d, c = %d, s = %d\n",
+ end_head, end_cyl, end_sector);
+#endif
+
+ physical_end = end_cyl * (end_head + 1) * end_sector +
+ end_head * end_sector + end_sector;
+
+ /* This is the actual _sector_ number at the end */
+ logical_end = get_unaligned(&largest->start_sect)
+ + get_unaligned(&largest->nr_sects);
+
+ /* This is for >1023 cylinders */
+ ext_cyl= (logical_end-(end_head * end_sector + end_sector))
+ /(end_head + 1) / end_sector;
+ ext_physical_end = ext_cyl * (end_head + 1) * end_sector +
+ end_head * end_sector + end_sector;
+
+#ifdef DEBUG
+ printk("scsicam_bios_param : logical_end=%d physical_end=%d ext_physical_end=%d ext_cyl=%d\n"
+ ,logical_end,physical_end,ext_physical_end,ext_cyl);
+#endif
+
+ if ((logical_end == physical_end) ||
+ (end_cyl==1023 && ext_physical_end==logical_end)) {
+ *secs = end_sector;
+ *hds = end_head + 1;
+ *cyls = capacity / ((end_head + 1) * end_sector);
+ return 0;
+ }
+
+#ifdef DEBUG
+ printk ("scsicam_bios_param : logical (%u) != physical (%u)\n",
+ logical_end, physical_end);
+#endif
+ }
+ return -1;
+}
+
+/*
+ * Function : static int setsize(unsigned long capacity,unsigned int *cyls,
+ * unsigned int *hds, unsigned int *secs);
+ *
+ * Purpose : to determine a near-optimal int 0x13 mapping for a
+ * SCSI disk in terms of lost space of size capacity, storing
+ * the results in *cyls, *hds, and *secs.
+ *
+ * Returns : -1 on failure, 0 on success.
+ *
+ * Extracted from
+ *
+ * WORKING X3T9.2
+ * DRAFT 792D
+ *
+ *
+ * Revision 6
+ * 10-MAR-94
+ * Information technology -
+ * SCSI-2 Common access method
+ * transport and SCSI interface module
+ *
+ * ANNEX A :
+ *
+ * setsize() converts a read capacity value to int 13h
+ * head-cylinder-sector requirements. It minimizes the value for
+ * number of heads and maximizes the number of cylinders. This
+ * will support rather large disks before the number of heads
+ * will not fit in 4 bits (or 6 bits). This algorithm also
+ * minimizes the number of sectors that will be unused at the end
+ * of the disk while allowing for very large disks to be
+ * accommodated. This algorithm does not use physical geometry.
+ */
+
+static int setsize(unsigned long capacity,unsigned int *cyls,unsigned int *hds,
+ unsigned int *secs) {
+ unsigned int rv = 0;
+ unsigned long heads, sectors, cylinders, temp;
+
+ cylinders = 1024L; /* Set number of cylinders to max */
+ sectors = 62L; /* Maximize sectors per track */
+
+ temp = cylinders * sectors; /* Compute divisor for heads */
+ heads = capacity / temp; /* Compute value for number of heads */
+ if (capacity % temp) { /* If no remainder, done! */
+ heads++; /* Else, increment number of heads */
+ temp = cylinders * heads; /* Compute divisor for sectors */
+ sectors = capacity / temp; /* Compute value for sectors per
+ track */
+ if (capacity % temp) { /* If no remainder, done! */
+ sectors++; /* Else, increment number of sectors */
+ temp = heads * sectors; /* Compute divisor for cylinders */
+ cylinders = capacity / temp;/* Compute number of cylinders */
+ }
+ }
+ if (cylinders == 0) rv=(unsigned)-1;/* Give error if 0 cylinders */
+
+ *cyls = (unsigned int) cylinders; /* Stuff return values */
+ *secs = (unsigned int) sectors;
+ *hds = (unsigned int) heads;
+ return(rv);
+}