patch-2.4.23 linux-2.4.23/arch/ia64/drivers/simscsi.c

• Lines: 397
• Date: 2003-11-28 10:26:19.000000000 -0800
• Orig file: linux-2.4.22/arch/ia64/drivers/simscsi.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.22/arch/ia64/drivers/simscsi.c linux-2.4.23/arch/ia64/drivers/simscsi.c
@@ -0,0 +1,396 @@
+/*
+ * Simulated SCSI driver.
+ *
+ * Copyright (C) 1999, 2001-2003 Hewlett-Packard Co
+ *	David Mosberger-Tang <davidm@hpl.hp.com>
+ *	Stephane Eranian <eranian@hpl.hp.com>
+ *
+ * 02/01/15 David Mosberger	Updated for v2.5.1
+ * 99/12/18 David Mosberger	Added support for READ10/WRITE10 needed by linux v2.3.33
+ */
+#include <linux/config.h>
+#include <linux/blk.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/timer.h>
+
+#include <scsi/scsi.h>
+
+#include <asm/irq.h>
+
+#include "../drivers/scsi/scsi.h"
+#include "../drivers/scsi/sd.h"
+#include "../drivers/scsi/hosts.h"
+#include "simscsi.h"
+
+#define DEBUG_SIMSCSI	1
+
+/* Simulator system calls: */
+
+#define SSC_OPEN			50
+#define SSC_CLOSE			51
+#define SSC_READ			52
+#define SSC_WRITE			53
+#define SSC_GET_COMPLETION		54
+#define SSC_WAIT_COMPLETION		55
+
+#define SSC_WRITE_ACCESS		2
+#define SSC_READ_ACCESS			1
+
+#if DEBUG_SIMSCSI
+  int simscsi_debug;
+# define DBG	simscsi_debug
+#else
+# define DBG	0
+#endif
+
+static void simscsi_interrupt (unsigned long val);
+DECLARE_TASKLET(simscsi_tasklet, simscsi_interrupt, 0);
+
+struct disk_req {
+	unsigned long addr;
+	unsigned len;
+};
+
+struct disk_stat {
+	int fd;
+	unsigned count;
+};
+
+extern long ia64_ssc (long arg0, long arg1, long arg2, long arg3, int nr);
+
+static int desc[16] = {
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
+};
+
+static struct queue_entry {
+	Scsi_Cmnd *sc;
+} queue[SIMSCSI_REQ_QUEUE_LEN];
+
+static int rd, wr;
+static atomic_t num_reqs = ATOMIC_INIT(0);
+
+/* base name for default disks */
+static char *simscsi_root = DEFAULT_SIMSCSI_ROOT;
+
+#define MAX_ROOT_LEN	128
+
+/*
+ * used to setup a new base for disk images
+ * to use /foo/bar/disk[a-z] as disk images
+ * you have to specify simscsi=/foo/bar/disk on the command line
+ */
+static int __init
+simscsi_setup (char *s)
+{
+	/* XXX Fix me we may need to strcpy() ? */
+	if (strlen(s) > MAX_ROOT_LEN) {
+		printk(KERN_ERR "simscsi_setup: prefix too long---using default %s\n",
+		       simscsi_root);
+	}
+	simscsi_root = s;
+	return 1;
+}
+
+__setup("simscsi=", simscsi_setup);
+
+static void
+simscsi_interrupt (unsigned long val)
+{
+	unsigned long flags;
+	Scsi_Cmnd *sc;
+
+	spin_lock_irqsave(&io_request_lock, flags);
+	{
+		while ((sc = queue[rd].sc) != 0) {
+			atomic_dec(&num_reqs);
+			queue[rd].sc = 0;
+			if (DBG)
+				printk("simscsi_interrupt: done with %ld\n", sc->serial_number);
+			(*sc->scsi_done)(sc);
+			rd = (rd + 1) % SIMSCSI_REQ_QUEUE_LEN;
+		}
+	}
+	spin_unlock_irqrestore(&io_request_lock, flags);
+}
+
+int
+simscsi_detect (Scsi_Host_Template *templ)
+{
+	templ->proc_name = "simscsi";
+	return 1;	/* fake one SCSI host adapter */
+}
+
+int
+simscsi_release (struct Scsi_Host *host)
+{
+	return 0;	/* this is easy...  */
+}
+
+const char *
+simscsi_info (struct Scsi_Host *host)
+{
+	return "simulated SCSI host adapter";
+}
+
+int
+simscsi_biosparam (Disk *disk, kdev_t n, int ip[])
+{
+	unsigned capacity = disk->capacity;
+
+	ip[0] = 64;		/* heads */
+	ip[1] = 32;		/* sectors */
+	ip[2] = capacity >> 11;	/* cylinders */
+	return 0;
+}
+
+static void
+simscsi_readwrite (Scsi_Cmnd *sc, int mode, unsigned long offset, unsigned long len)
+{
+	struct disk_stat stat;
+	struct disk_req req;
+
+	req.addr = __pa(sc->request_buffer);
+	req.len  = len;			/* # of bytes to transfer */
+
+	if (sc->request_bufflen < req.len)
+		return;
+
+	stat.fd = desc[sc->target];
+	if (DBG)
+		printk("simscsi_%s @ %lx (off %lx)\n",
+		       mode == SSC_READ ? "read":"write", req.addr, offset);
+	ia64_ssc(stat.fd, 1, __pa(&req), offset, mode);
+	ia64_ssc(__pa(&stat), 0, 0, 0, SSC_WAIT_COMPLETION);
+
+	if (stat.count == req.len) {
+		sc->result = GOOD;
+	} else {
+		sc->result = DID_ERROR << 16;
+	}
+}
+
+static void
+simscsi_sg_readwrite (Scsi_Cmnd *sc, int mode, unsigned long offset)
+{
+	int list_len = sc->use_sg;
+	struct scatterlist *sl = (struct scatterlist *)sc->buffer;
+	struct disk_stat stat;
+	struct disk_req req;
+
+	stat.fd = desc[sc->target];
+
+	while (list_len) {
+		req.addr = __pa(sl->address);
+		req.len  = sl->length;
+		if (DBG)
+			printk("simscsi_sg_%s @ %lx (off %lx) use_sg=%d len=%d\n",
+			       mode == SSC_READ ? "read":"write", req.addr, offset,
+			       list_len, sl->length);
+		ia64_ssc(stat.fd, 1, __pa(&req), offset, mode);
+		ia64_ssc(__pa(&stat), 0, 0, 0, SSC_WAIT_COMPLETION);
+
+		/* should not happen in our case */
+		if (stat.count != req.len) {
+			sc->result = DID_ERROR << 16;
+			return;
+		}
+		offset +=  sl->length;
+		sl++;
+		list_len--;
+	}
+	sc->result = GOOD;
+}
+
+/*
+ * function handling both READ_6/WRITE_6 (non-scatter/gather mode)
+ * commands.
+ * Added 02/26/99 S.Eranian
+ */
+static void
+simscsi_readwrite6 (Scsi_Cmnd *sc, int mode)
+{
+	unsigned long offset;
+
+	offset = (((sc->cmnd[1] & 0x1f) << 16) | (sc->cmnd[2] << 8) | sc->cmnd[3])*512;
+	if (sc->use_sg > 0)
+		simscsi_sg_readwrite(sc, mode, offset);
+	else
+		simscsi_readwrite(sc, mode, offset, sc->cmnd[4]*512);
+}
+
+static size_t
+simscsi_get_disk_size (int fd)
+{
+	struct disk_stat stat;
+	size_t bit, sectors = 0;
+	struct disk_req req;
+	char buf[512];
+
+	/*
+	 * This is a bit kludgey: the simulator doesn't provide a direct way of determining
+	 * the disk size, so we do a binary search, assuming a maximum disk size of 4GB.
+	 */
+	for (bit = (4UL << 30)/512; bit != 0; bit >>= 1) {
+		req.addr = __pa(&buf);
+		req.len = sizeof(buf);
+		ia64_ssc(fd, 1, __pa(&req), ((sectors | bit) - 1)*512, SSC_READ);
+		stat.fd = fd;
+		ia64_ssc(__pa(&stat), 0, 0, 0, SSC_WAIT_COMPLETION);
+		if (stat.count == sizeof(buf))
+			sectors |= bit;
+	}
+	return sectors - 1;	/* return last valid sector number */
+}
+
+static void
+simscsi_readwrite10 (Scsi_Cmnd *sc, int mode)
+{
+	unsigned long offset;
+
+	offset = (  (sc->cmnd[2] << 24) | (sc->cmnd[3] << 16)
+		  | (sc->cmnd[4] <<  8) | (sc->cmnd[5] <<  0))*512;
+	if (sc->use_sg > 0)
+		simscsi_sg_readwrite(sc, mode, offset);
+	else
+		simscsi_readwrite(sc, mode, offset, ((sc->cmnd[7] << 8) | sc->cmnd[8])*512);
+}
+
+int
+simscsi_queuecommand (Scsi_Cmnd *sc, void (*done)(Scsi_Cmnd *))
+{
+	char fname[MAX_ROOT_LEN+16];
+	size_t disk_size;
+	char *buf;
+#if DEBUG_SIMSCSI
+	register long sp asm ("sp");
+
+	if (DBG)
+		printk("simscsi_queuecommand: target=%d,cmnd=%u,sc=%lu,sp=%lx,done=%p\n",
+		       sc->target, sc->cmnd[0], sc->serial_number, sp, done);
+#endif
+
+	sc->result = DID_BAD_TARGET << 16;
+	sc->scsi_done = done;
+	if (sc->target <= 15 && sc->lun == 0) {
+		switch (sc->cmnd[0]) {
+		      case INQUIRY:
+			if (sc->request_bufflen < 35) {
+				break;
+			}
+			sprintf (fname, "%s%c", simscsi_root, 'a' + sc->target);
+			desc[sc->target] = ia64_ssc(__pa(fname), SSC_READ_ACCESS|SSC_WRITE_ACCESS,
+						    0, 0, SSC_OPEN);
+			if (desc[sc->target] < 0) {
+				/* disk doesn't exist... */
+				break;
+			}
+			buf = sc->request_buffer;
+			buf[0] = 0;	/* magnetic disk */
+			buf[1] = 0;	/* not a removable medium */
+			buf[2] = 2;	/* SCSI-2 compliant device */
+			buf[3] = 2;	/* SCSI-2 response data format */
+			buf[4] = 31;	/* additional length (bytes) */
+			buf[5] = 0;	/* reserved */
+			buf[6] = 0;	/* reserved */
+			buf[7] = 0;	/* various flags */
+			memcpy(buf + 8, "HP      SIMULATED DISK  0.00",  28);
+			sc->result = GOOD;
+			break;
+
+		      case TEST_UNIT_READY:
+			sc->result = GOOD;
+			break;
+
+		      case READ_6:
+			if (desc[sc->target] < 0 )
+				break;
+			simscsi_readwrite6(sc, SSC_READ);
+			break;
+
+		      case READ_10:
+			if (desc[sc->target] < 0 )
+				break;
+			simscsi_readwrite10(sc, SSC_READ);
+			break;
+
+		      case WRITE_6:
+			if (desc[sc->target] < 0)
+				break;
+			simscsi_readwrite6(sc, SSC_WRITE);
+			break;
+
+		      case WRITE_10:
+			if (desc[sc->target] < 0)
+				break;
+			simscsi_readwrite10(sc, SSC_WRITE);
+			break;
+
+
+		      case READ_CAPACITY:
+			if (desc[sc->target] < 0 || sc->request_bufflen < 8) {
+				break;
+			}
+			buf = sc->request_buffer;
+
+			disk_size = simscsi_get_disk_size(desc[sc->target]);
+			buf[0] = (disk_size >> 24) & 0xff;
+			buf[1] = (disk_size >> 16) & 0xff;
+			buf[2] = (disk_size >>  8) & 0xff;
+			buf[3] = (disk_size >>  0) & 0xff;
+			/* set block size of 512 bytes: */
+			buf[4] = 0;
+			buf[5] = 0;
+			buf[6] = 2;
+			buf[7] = 0;
+			sc->result = GOOD;
+			break;
+
+		      case MODE_SENSE:
+			/* sd.c uses this to determine whether disk does write-caching. */
+			memset(sc->request_buffer, 0, 128);
+			sc->result = GOOD;
+			break;
+
+		      case START_STOP:
+			printk(KERN_ERR "START_STOP\n");
+			break;
+
+		      default:
+			panic("simscsi: unknown SCSI command %u\n", sc->cmnd[0]);
+		}
+	}
+	if (sc->result == DID_BAD_TARGET) {
+		sc->result |= DRIVER_SENSE << 24;
+		sc->sense_buffer[0] = 0x70;
+		sc->sense_buffer[2] = 0x00;
+	}
+	if (atomic_read(&num_reqs) >= SIMSCSI_REQ_QUEUE_LEN) {
+		panic("Attempt to queue command while command is pending!!");
+	}
+	atomic_inc(&num_reqs);
+	queue[wr].sc = sc;
+	wr = (wr + 1) % SIMSCSI_REQ_QUEUE_LEN;
+
+	tasklet_schedule(&simscsi_tasklet);
+	return 0;
+}
+
+int
+simscsi_reset (Scsi_Cmnd *cmd, unsigned int reset_flags)
+{
+	printk(KERN_ERR "simscsi_reset: unimplemented\n");
+	return SCSI_RESET_SUCCESS;
+}
+
+int
+simscsi_abort (Scsi_Cmnd *cmd)
+{
+	printk(KERN_ERR "simscsi_abort: unimplemented\n");
+	return SCSI_ABORT_SUCCESS;
+}
+
+static Scsi_Host_Template driver_template = SIMSCSI;
+
+#include "../drivers/scsi/scsi_module.c"