swh:1:snp:3c665ee4f67729f27f2e40193ab88e7298cf0fef
Tip revision: c3b92c8787367a8bb53d57d9789b558f1295cc96 authored by Linus Torvalds on 24 October 2011, 07:10:05 UTC
Linux 3.1
Linux 3.1
Tip revision: c3b92c8
scsiglue.c
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_devinfo.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_eh.h>
#include "usb.h"
#include "scsiglue.h"
#include "transport.h"
/* Host functions */
/*
* host_info()
*/
static const char *host_info(struct Scsi_Host *host)
{
/* pr_info("scsiglue --- host_info\n"); */
return "SCSI emulation for USB Mass Storage devices";
}
/*
* slave_alloc()
*/
static int slave_alloc(struct scsi_device *sdev)
{
struct us_data *us = host_to_us(sdev->host);
/* pr_info("scsiglue --- slave_alloc\n"); */
sdev->inquiry_len = 36;
blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
if (us->subclass == USB_SC_UFI)
sdev->sdev_target->pdt_1f_for_no_lun = 1;
return 0;
}
/*
* slave_configure()
*/
static int slave_configure(struct scsi_device *sdev)
{
struct us_data *us = host_to_us(sdev->host);
/* pr_info("scsiglue --- slave_configure\n"); */
if (us->fflags & (US_FL_MAX_SECTORS_64 | US_FL_MAX_SECTORS_MIN)) {
unsigned int max_sectors = 64;
if (us->fflags & US_FL_MAX_SECTORS_MIN)
max_sectors = PAGE_CACHE_SIZE >> 9;
if (queue_max_sectors(sdev->request_queue) > max_sectors)
blk_queue_max_hw_sectors(sdev->request_queue,
max_sectors);
}
if (sdev->type == TYPE_DISK) {
if (us->subclass != USB_SC_SCSI &&
us->subclass != USB_SC_CYP_ATACB)
sdev->use_10_for_ms = 1;
sdev->use_192_bytes_for_3f = 1;
if (us->fflags & US_FL_NO_WP_DETECT)
sdev->skip_ms_page_3f = 1;
sdev->skip_ms_page_8 = 1;
if (us->fflags & US_FL_FIX_CAPACITY)
sdev->fix_capacity = 1;
if (us->fflags & US_FL_CAPACITY_HEURISTICS)
sdev->guess_capacity = 1;
if (sdev->scsi_level > SCSI_2)
sdev->sdev_target->scsi_level = sdev->scsi_level = SCSI_2;
sdev->retry_hwerror = 1;
sdev->allow_restart = 1;
sdev->last_sector_bug = 1;
} else {
sdev->use_10_for_ms = 1;
}
if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_CBI) &&
sdev->scsi_level == SCSI_UNKNOWN)
us->max_lun = 0;
if (us->fflags & US_FL_NOT_LOCKABLE)
sdev->lockable = 0;
return 0;
}
/* This is always called with scsi_lock(host) held */
/*
* queuecommand()
*/
static int queuecommand_lck(struct scsi_cmnd *srb,
void (*done)(struct scsi_cmnd *))
{
struct us_data *us = host_to_us(srb->device->host);
/* pr_info("scsiglue --- queuecommand\n"); */
/* check for state-transition errors */
if (us->srb != NULL) {
/* pr_info("Error in %s: us->srb = %p\n"
__FUNCTION__, us->srb); */
return SCSI_MLQUEUE_HOST_BUSY;
}
/* fail the command if we are disconnecting */
if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
pr_info("Fail command during disconnect\n");
srb->result = DID_NO_CONNECT << 16;
done(srb);
return 0;
}
/* enqueue the command and wake up the control thread */
srb->scsi_done = done;
us->srb = srb;
complete(&us->cmnd_ready);
return 0;
}
static DEF_SCSI_QCMD(queuecommand)
/***********************************************************************
* Error handling functions
***********************************************************************/
/* Command timeout and abort */
/*
* command_abort()
*/
static int command_abort(struct scsi_cmnd *srb)
{
struct us_data *us = host_to_us(srb->device->host);
/* pr_info("scsiglue --- command_abort\n"); */
scsi_lock(us_to_host(us));
if (us->srb != srb) {
scsi_unlock(us_to_host(us));
printk ("-- nothing to abort\n");
return FAILED;
}
set_bit(US_FLIDX_TIMED_OUT, &us->dflags);
if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) {
set_bit(US_FLIDX_ABORTING, &us->dflags);
usb_stor_stop_transport(us);
}
scsi_unlock(us_to_host(us));
/* Wait for the aborted command to finish */
wait_for_completion(&us->notify);
return SUCCESS;
}
/* This invokes the transport reset mechanism to reset the state of the
* device.
*/
/*
* device_reset()
*/
static int device_reset(struct scsi_cmnd *srb)
{
struct us_data *us = host_to_us(srb->device->host);
int result;
/* pr_info("scsiglue --- device_reset\n"); */
/* lock the device pointers and do the reset */
mutex_lock(&(us->dev_mutex));
result = us->transport_reset(us);
mutex_unlock(&us->dev_mutex);
return result < 0 ? FAILED : SUCCESS;
}
/*
* bus_reset()
*/
static int bus_reset(struct scsi_cmnd *srb)
{
struct us_data *us = host_to_us(srb->device->host);
int result;
/* pr_info("scsiglue --- bus_reset\n"); */
result = usb_stor_port_reset(us);
return result < 0 ? FAILED : SUCCESS;
}
/*
* usb_stor_report_device_reset()
*/
void usb_stor_report_device_reset(struct us_data *us)
{
int i;
struct Scsi_Host *host = us_to_host(us);
/* pr_info("scsiglue --- usb_stor_report_device_reset\n"); */
scsi_report_device_reset(host, 0, 0);
if (us->fflags & US_FL_SCM_MULT_TARG) {
for (i = 1; i < host->max_id; ++i)
scsi_report_device_reset(host, 0, i);
}
}
/*
* usb_stor_report_bus_reset()
*/
void usb_stor_report_bus_reset(struct us_data *us)
{
struct Scsi_Host *host = us_to_host(us);
/* pr_info("scsiglue --- usb_stor_report_bus_reset\n"); */
scsi_lock(host);
scsi_report_bus_reset(host, 0);
scsi_unlock(host);
}
/***********************************************************************
* /proc/scsi/ functions
***********************************************************************/
/* we use this macro to help us write into the buffer */
#undef SPRINTF
#define SPRINTF(args...) \
do { if (pos < buffer+length) pos += sprintf(pos, ## args); } while (0)
/*
* proc_info()
*/
static int proc_info(struct Scsi_Host *host, char *buffer, char **start,
off_t offset, int length, int inout)
{
struct us_data *us = host_to_us(host);
char *pos = buffer;
const char *string;
/* pr_info("scsiglue --- proc_info\n"); */
if (inout)
return length;
/* print the controller name */
SPRINTF(" Host scsi%d: usb-storage\n", host->host_no);
/* print product, vendor, and serial number strings */
if (us->pusb_dev->manufacturer)
string = us->pusb_dev->manufacturer;
else if (us->unusual_dev->vendorName)
string = us->unusual_dev->vendorName;
else
string = "Unknown";
SPRINTF(" Vendor: %s\n", string);
if (us->pusb_dev->product)
string = us->pusb_dev->product;
else if (us->unusual_dev->productName)
string = us->unusual_dev->productName;
else
string = "Unknown";
SPRINTF(" Product: %s\n", string);
if (us->pusb_dev->serial)
string = us->pusb_dev->serial;
else
string = "None";
SPRINTF("Serial Number: %s\n", string);
/* show the protocol and transport */
SPRINTF(" Protocol: %s\n", us->protocol_name);
SPRINTF(" Transport: %s\n", us->transport_name);
/* show the device flags */
if (pos < buffer + length) {
pos += sprintf(pos, " Quirks:");
#define US_FLAG(name, value) \
if (us->fflags & value) pos += sprintf(pos, " " #name);
US_DO_ALL_FLAGS
#undef US_FLAG
*(pos++) = '\n';
}
/* Calculate start of next buffer, and return value. */
*start = buffer + offset;
if ((pos - buffer) < offset)
return 0;
else if ((pos - buffer - offset) < length)
return pos - buffer - offset;
else
return length;
}
/***********************************************************************
* Sysfs interface
***********************************************************************/
/* Output routine for the sysfs max_sectors file */
/*
* show_max_sectors()
*/
static ssize_t show_max_sectors(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct scsi_device *sdev = to_scsi_device(dev);
/* pr_info("scsiglue --- ssize_t show_max_sectors\n"); */
return sprintf(buf, "%u\n", queue_max_sectors(sdev->request_queue));
}
/* Input routine for the sysfs max_sectors file */
/*
* store_max_sectors()
*/
static ssize_t store_max_sectors(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct scsi_device *sdev = to_scsi_device(dev);
unsigned short ms;
/* pr_info("scsiglue --- ssize_t store_max_sectors\n"); */
if (sscanf(buf, "%hu", &ms) > 0 && ms <= SCSI_DEFAULT_MAX_SECTORS) {
blk_queue_max_hw_sectors(sdev->request_queue, ms);
return strlen(buf);
}
return -EINVAL;
}
static DEVICE_ATTR(max_sectors, S_IRUGO | S_IWUSR, show_max_sectors, store_max_sectors);
static struct device_attribute *sysfs_device_attr_list[] = {&dev_attr_max_sectors, NULL, };
/* this defines our host template, with which we'll allocate hosts */
/*
* usb_stor_host_template()
*/
struct scsi_host_template usb_stor_host_template = {
/* basic userland interface stuff */
.name = "eucr-storage",
.proc_name = "eucr-storage",
.proc_info = proc_info,
.info = host_info,
/* command interface -- queued only */
.queuecommand = queuecommand,
/* error and abort handlers */
.eh_abort_handler = command_abort,
.eh_device_reset_handler = device_reset,
.eh_bus_reset_handler = bus_reset,
/* queue commands only, only one command per LUN */
.can_queue = 1,
.cmd_per_lun = 1,
/* unknown initiator id */
.this_id = -1,
.slave_alloc = slave_alloc,
.slave_configure = slave_configure,
/* lots of sg segments can be handled */
.sg_tablesize = SG_ALL,
/* limit the total size of a transfer to 120 KB */
.max_sectors = 240,
/* merge commands... this seems to help performance, but
* periodically someone should test to see which setting is more
* optimal.
*/
.use_clustering = 1,
/* emulated HBA */
.emulated = 1,
/* we do our own delay after a device or bus reset */
.skip_settle_delay = 1,
/* sysfs device attributes */
.sdev_attrs = sysfs_device_attr_list,
/* module management */
.module = THIS_MODULE
};
/* To Report "Illegal Request: Invalid Field in CDB */
unsigned char usb_stor_sense_invalidCDB[18] = {
[0] = 0x70, /* current error */
[2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */
[7] = 0x0a, /* additional length */
[12] = 0x24 /* Invalid Field in CDB */
};
/***********************************************************************
* Scatter-gather transfer buffer access routines
***********************************************************************/
/*
* usb_stor_access_xfer_buf()
*/
unsigned int usb_stor_access_xfer_buf(struct us_data *us, unsigned char *buffer,
unsigned int buflen, struct scsi_cmnd *srb, struct scatterlist **sgptr,
unsigned int *offset, enum xfer_buf_dir dir)
{
unsigned int cnt;
/* pr_info("transport --- usb_stor_access_xfer_buf\n"); */
struct scatterlist *sg = *sgptr;
if (!sg)
sg = scsi_sglist(srb);
cnt = 0;
while (cnt < buflen && sg) {
struct page *page = sg_page(sg) +
((sg->offset + *offset) >> PAGE_SHIFT);
unsigned int poff = (sg->offset + *offset) & (PAGE_SIZE-1);
unsigned int sglen = sg->length - *offset;
if (sglen > buflen - cnt) {
/* Transfer ends within this s-g entry */
sglen = buflen - cnt;
*offset += sglen;
} else {
/* Transfer continues to next s-g entry */
*offset = 0;
sg = sg_next(sg);
}
while (sglen > 0) {
unsigned int plen = min(sglen,
(unsigned int)PAGE_SIZE - poff);
unsigned char *ptr = kmap(page);
if (dir == TO_XFER_BUF)
memcpy(ptr + poff, buffer + cnt, plen);
else
memcpy(buffer + cnt, ptr + poff, plen);
kunmap(page);
/* Start at the beginning of the next page */
poff = 0;
++page;
cnt += plen;
sglen -= plen;
}
}
*sgptr = sg;
/* Return the amount actually transferred */
return cnt;
}
/*
* Store the contents of buffer into srb's transfer
* buffer and set the SCSI residue.
*/
/*
* usb_stor_set_xfer_buf()
*/
void usb_stor_set_xfer_buf(struct us_data *us, unsigned char *buffer,
unsigned int buflen, struct scsi_cmnd *srb, unsigned int dir)
{
unsigned int offset = 0;
struct scatterlist *sg = NULL;
/* pr_info("transport --- usb_stor_set_xfer_buf\n"); */
/* TO_XFER_BUF = 0, FROM_XFER_BUF = 1 */
buflen = min(buflen, scsi_bufflen(srb));
buflen = usb_stor_access_xfer_buf(us, buffer, buflen, srb,
&sg, &offset, dir);
if (buflen < scsi_bufflen(srb))
scsi_set_resid(srb, scsi_bufflen(srb) - buflen);
}