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linux/drivers/usb/storage/jumpshot.c
Julia Lawall 64aebe7315 USB: storage: Drop an unneeded a NULL test 
In each case, the NULL test is not necessary because the function is static
and at the only places where it is called, the us argument has already been
dereferenced.

The semantic patch that finds the problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
type T;
expression E,E1;
identifier i,fld;
statement S;
@@

- T i = E->fld;
+ T i;
  ... when != E=E1
      when != i
  if (E == NULL||...) S
+ i = E->fld;
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23 06:46:29 -07:00

694 lines
18 KiB
C
Raw Blame History

/* Driver for Lexar "Jumpshot" Compact Flash reader
*
* jumpshot driver v0.1:
*
* First release
*
* Current development and maintenance by:
* (c) 2000 Jimmie Mayfield (mayfield+usb@sackheads.org)
*
* Many thanks to Robert Baruch for the SanDisk SmartMedia reader driver
* which I used as a template for this driver.
*
* Some bugfixes and scatter-gather code by Gregory P. Smith
* (greg-usb@electricrain.com)
*
* Fix for media change by Joerg Schneider (js@joergschneider.com)
*
* Developed with the assistance of:
*
* (C) 2002 Alan Stern <stern@rowland.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
* This driver attempts to support the Lexar Jumpshot USB CompactFlash
* reader. Like many other USB CompactFlash readers, the Jumpshot contains
* a USB-to-ATA chip.
*
* This driver supports reading and writing. If you're truly paranoid,
* however, you can force the driver into a write-protected state by setting
* the WP enable bits in jumpshot_handle_mode_sense. See the comments
* in that routine.
*/
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include "usb.h"
#include "transport.h"
#include "protocol.h"
#include "debug.h"
MODULE_DESCRIPTION("Driver for Lexar \"Jumpshot\" Compact Flash reader");
MODULE_AUTHOR("Jimmie Mayfield <mayfield+usb@sackheads.org>");
MODULE_LICENSE("GPL");
/*
* The table of devices
*/
#define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
vendorName, productName, useProtocol, useTransport, \
initFunction, flags) \
{ USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
.driver_info = (flags)|(USB_US_TYPE_STOR<<24) }
struct usb_device_id jumpshot_usb_ids[] = {
# include "unusual_jumpshot.h"
{ } /* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, jumpshot_usb_ids);
#undef UNUSUAL_DEV
/*
* The flags table
*/
#define UNUSUAL_DEV(idVendor, idProduct, bcdDeviceMin, bcdDeviceMax, \
vendor_name, product_name, use_protocol, use_transport, \
init_function, Flags) \
{ \
.vendorName = vendor_name, \
.productName = product_name, \
.useProtocol = use_protocol, \
.useTransport = use_transport, \
.initFunction = init_function, \
}
static struct us_unusual_dev jumpshot_unusual_dev_list[] = {
# include "unusual_jumpshot.h"
{ } /* Terminating entry */
};
#undef UNUSUAL_DEV
struct jumpshot_info {
unsigned long sectors; /* total sector count */
unsigned long ssize; /* sector size in bytes */
/* the following aren't used yet */
unsigned char sense_key;
unsigned long sense_asc; /* additional sense code */
unsigned long sense_ascq; /* additional sense code qualifier */
};
static inline int jumpshot_bulk_read(struct us_data *us,
unsigned char *data,
unsigned int len)
{
if (len == 0)
return USB_STOR_XFER_GOOD;
US_DEBUGP("jumpshot_bulk_read: len = %d\n", len);
return usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
data, len, NULL);
}
static inline int jumpshot_bulk_write(struct us_data *us,
unsigned char *data,
unsigned int len)
{
if (len == 0)
return USB_STOR_XFER_GOOD;
US_DEBUGP("jumpshot_bulk_write: len = %d\n", len);
return usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
data, len, NULL);
}
static int jumpshot_get_status(struct us_data *us)
{
int rc;
if (!us)
return USB_STOR_TRANSPORT_ERROR;
// send the setup
rc = usb_stor_ctrl_transfer(us, us->recv_ctrl_pipe,
0, 0xA0, 0, 7, us->iobuf, 1);
if (rc != USB_STOR_XFER_GOOD)
return USB_STOR_TRANSPORT_ERROR;
if (us->iobuf[0] != 0x50) {
US_DEBUGP("jumpshot_get_status: 0x%2x\n",
us->iobuf[0]);
return USB_STOR_TRANSPORT_ERROR;
}
return USB_STOR_TRANSPORT_GOOD;
}
static int jumpshot_read_data(struct us_data *us,
struct jumpshot_info *info,
u32 sector,
u32 sectors)
{
unsigned char *command = us->iobuf;
unsigned char *buffer;
unsigned char thistime;
unsigned int totallen, alloclen;
int len, result;
unsigned int sg_offset = 0;
struct scatterlist *sg = NULL;
// we're working in LBA mode. according to the ATA spec,
// we can support up to 28-bit addressing. I don't know if Jumpshot
// supports beyond 24-bit addressing. It's kind of hard to test
// since it requires > 8GB CF card.
if (sector > 0x0FFFFFFF)
return USB_STOR_TRANSPORT_ERROR;
totallen = sectors * info->ssize;
// Since we don't read more than 64 KB at a time, we have to create
// a bounce buffer and move the data a piece at a time between the
// bounce buffer and the actual transfer buffer.
alloclen = min(totallen, 65536u);
buffer = kmalloc(alloclen, GFP_NOIO);
if (buffer == NULL)
return USB_STOR_TRANSPORT_ERROR;
do {
// loop, never allocate or transfer more than 64k at once
// (min(128k, 255*info->ssize) is the real limit)
len = min(totallen, alloclen);
thistime = (len / info->ssize) & 0xff;
command[0] = 0;
command[1] = thistime;
command[2] = sector & 0xFF;
command[3] = (sector >> 8) & 0xFF;
command[4] = (sector >> 16) & 0xFF;
command[5] = 0xE0 | ((sector >> 24) & 0x0F);
command[6] = 0x20;
// send the setup + command
result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
0, 0x20, 0, 1, command, 7);
if (result != USB_STOR_XFER_GOOD)
goto leave;
// read the result
result = jumpshot_bulk_read(us, buffer, len);
if (result != USB_STOR_XFER_GOOD)
goto leave;
US_DEBUGP("jumpshot_read_data: %d bytes\n", len);
// Store the data in the transfer buffer
usb_stor_access_xfer_buf(buffer, len, us->srb,
&sg, &sg_offset, TO_XFER_BUF);
sector += thistime;
totallen -= len;
} while (totallen > 0);
kfree(buffer);
return USB_STOR_TRANSPORT_GOOD;
leave:
kfree(buffer);
return USB_STOR_TRANSPORT_ERROR;
}
static int jumpshot_write_data(struct us_data *us,
struct jumpshot_info *info,
u32 sector,
u32 sectors)
{
unsigned char *command = us->iobuf;
unsigned char *buffer;
unsigned char thistime;
unsigned int totallen, alloclen;
int len, result, waitcount;
unsigned int sg_offset = 0;
struct scatterlist *sg = NULL;
// we're working in LBA mode. according to the ATA spec,
// we can support up to 28-bit addressing. I don't know if Jumpshot
// supports beyond 24-bit addressing. It's kind of hard to test
// since it requires > 8GB CF card.
//
if (sector > 0x0FFFFFFF)
return USB_STOR_TRANSPORT_ERROR;
totallen = sectors * info->ssize;
// Since we don't write more than 64 KB at a time, we have to create
// a bounce buffer and move the data a piece at a time between the
// bounce buffer and the actual transfer buffer.
alloclen = min(totallen, 65536u);
buffer = kmalloc(alloclen, GFP_NOIO);
if (buffer == NULL)
return USB_STOR_TRANSPORT_ERROR;
do {
// loop, never allocate or transfer more than 64k at once
// (min(128k, 255*info->ssize) is the real limit)
len = min(totallen, alloclen);
thistime = (len / info->ssize) & 0xff;
// Get the data from the transfer buffer
usb_stor_access_xfer_buf(buffer, len, us->srb,
&sg, &sg_offset, FROM_XFER_BUF);
command[0] = 0;
command[1] = thistime;
command[2] = sector & 0xFF;
command[3] = (sector >> 8) & 0xFF;
command[4] = (sector >> 16) & 0xFF;
command[5] = 0xE0 | ((sector >> 24) & 0x0F);
command[6] = 0x30;
// send the setup + command
result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
0, 0x20, 0, 1, command, 7);
if (result != USB_STOR_XFER_GOOD)
goto leave;
// send the data
result = jumpshot_bulk_write(us, buffer, len);
if (result != USB_STOR_XFER_GOOD)
goto leave;
// read the result. apparently the bulk write can complete
// before the jumpshot drive is finished writing. so we loop
// here until we get a good return code
waitcount = 0;
do {
result = jumpshot_get_status(us);
if (result != USB_STOR_TRANSPORT_GOOD) {
// I have not experimented to find the smallest value.
//
msleep(50);
}
} while ((result != USB_STOR_TRANSPORT_GOOD) && (waitcount < 10));
if (result != USB_STOR_TRANSPORT_GOOD)
US_DEBUGP("jumpshot_write_data: Gah! Waitcount = 10. Bad write!?\n");
sector += thistime;
totallen -= len;
} while (totallen > 0);
kfree(buffer);
return result;
leave:
kfree(buffer);
return USB_STOR_TRANSPORT_ERROR;
}
static int jumpshot_id_device(struct us_data *us,
struct jumpshot_info *info)
{
unsigned char *command = us->iobuf;
unsigned char *reply;
int rc;
if (!info)
return USB_STOR_TRANSPORT_ERROR;
command[0] = 0xE0;
command[1] = 0xEC;
reply = kmalloc(512, GFP_NOIO);
if (!reply)
return USB_STOR_TRANSPORT_ERROR;
// send the setup
rc = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
0, 0x20, 0, 6, command, 2);
if (rc != USB_STOR_XFER_GOOD) {
US_DEBUGP("jumpshot_id_device: Gah! "
"send_control for read_capacity failed\n");
rc = USB_STOR_TRANSPORT_ERROR;
goto leave;
}
// read the reply
rc = jumpshot_bulk_read(us, reply, 512);
if (rc != USB_STOR_XFER_GOOD) {
rc = USB_STOR_TRANSPORT_ERROR;
goto leave;
}
info->sectors = ((u32)(reply[117]) << 24) |
((u32)(reply[116]) << 16) |
((u32)(reply[115]) << 8) |
((u32)(reply[114]) );
rc = USB_STOR_TRANSPORT_GOOD;
leave:
kfree(reply);
return rc;
}
static int jumpshot_handle_mode_sense(struct us_data *us,
struct scsi_cmnd * srb,
int sense_6)
{
static unsigned char rw_err_page[12] = {
0x1, 0xA, 0x21, 1, 0, 0, 0, 0, 1, 0, 0, 0
};
static unsigned char cache_page[12] = {
0x8, 0xA, 0x1, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
static unsigned char rbac_page[12] = {
0x1B, 0xA, 0, 0x81, 0, 0, 0, 0, 0, 0, 0, 0
};
static unsigned char timer_page[8] = {
0x1C, 0x6, 0, 0, 0, 0
};
unsigned char pc, page_code;
unsigned int i = 0;
struct jumpshot_info *info = (struct jumpshot_info *) (us->extra);
unsigned char *ptr = us->iobuf;
pc = srb->cmnd[2] >> 6;
page_code = srb->cmnd[2] & 0x3F;
switch (pc) {
case 0x0:
US_DEBUGP("jumpshot_handle_mode_sense: Current values\n");
break;
case 0x1:
US_DEBUGP("jumpshot_handle_mode_sense: Changeable values\n");
break;
case 0x2:
US_DEBUGP("jumpshot_handle_mode_sense: Default values\n");
break;
case 0x3:
US_DEBUGP("jumpshot_handle_mode_sense: Saves values\n");
break;
}
memset(ptr, 0, 8);
if (sense_6) {
ptr[2] = 0x00; // WP enable: 0x80
i = 4;
} else {
ptr[3] = 0x00; // WP enable: 0x80
i = 8;
}
switch (page_code) {
case 0x0:
// vendor-specific mode
info->sense_key = 0x05;
info->sense_asc = 0x24;
info->sense_ascq = 0x00;
return USB_STOR_TRANSPORT_FAILED;
case 0x1:
memcpy(ptr + i, rw_err_page, sizeof(rw_err_page));
i += sizeof(rw_err_page);
break;
case 0x8:
memcpy(ptr + i, cache_page, sizeof(cache_page));
i += sizeof(cache_page);
break;
case 0x1B:
memcpy(ptr + i, rbac_page, sizeof(rbac_page));
i += sizeof(rbac_page);
break;
case 0x1C:
memcpy(ptr + i, timer_page, sizeof(timer_page));
i += sizeof(timer_page);
break;
case 0x3F:
memcpy(ptr + i, timer_page, sizeof(timer_page));
i += sizeof(timer_page);
memcpy(ptr + i, rbac_page, sizeof(rbac_page));
i += sizeof(rbac_page);
memcpy(ptr + i, cache_page, sizeof(cache_page));
i += sizeof(cache_page);
memcpy(ptr + i, rw_err_page, sizeof(rw_err_page));
i += sizeof(rw_err_page);
break;
}
if (sense_6)
ptr[0] = i - 1;
else
((__be16 *) ptr)[0] = cpu_to_be16(i - 2);
usb_stor_set_xfer_buf(ptr, i, srb);
return USB_STOR_TRANSPORT_GOOD;
}
static void jumpshot_info_destructor(void *extra)
{
// this routine is a placeholder...
// currently, we don't allocate any extra blocks so we're okay
}
// Transport for the Lexar 'Jumpshot'
//
static int jumpshot_transport(struct scsi_cmnd *srb, struct us_data *us)
{
struct jumpshot_info *info;
int rc;
unsigned long block, blocks;
unsigned char *ptr = us->iobuf;
static unsigned char inquiry_response[8] = {
0x00, 0x80, 0x00, 0x01, 0x1F, 0x00, 0x00, 0x00
};
if (!us->extra) {
us->extra = kzalloc(sizeof(struct jumpshot_info), GFP_NOIO);
if (!us->extra) {
US_DEBUGP("jumpshot_transport: Gah! Can't allocate storage for jumpshot info struct!\n");
return USB_STOR_TRANSPORT_ERROR;
}
us->extra_destructor = jumpshot_info_destructor;
}
info = (struct jumpshot_info *) (us->extra);
if (srb->cmnd[0] == INQUIRY) {
US_DEBUGP("jumpshot_transport: INQUIRY. Returning bogus response.\n");
memcpy(ptr, inquiry_response, sizeof(inquiry_response));
fill_inquiry_response(us, ptr, 36);
return USB_STOR_TRANSPORT_GOOD;
}
if (srb->cmnd[0] == READ_CAPACITY) {
info->ssize = 0x200; // hard coded 512 byte sectors as per ATA spec
rc = jumpshot_get_status(us);
if (rc != USB_STOR_TRANSPORT_GOOD)
return rc;
rc = jumpshot_id_device(us, info);
if (rc != USB_STOR_TRANSPORT_GOOD)
return rc;
US_DEBUGP("jumpshot_transport: READ_CAPACITY: %ld sectors, %ld bytes per sector\n",
info->sectors, info->ssize);
// build the reply
//
((__be32 *) ptr)[0] = cpu_to_be32(info->sectors - 1);
((__be32 *) ptr)[1] = cpu_to_be32(info->ssize);
usb_stor_set_xfer_buf(ptr, 8, srb);
return USB_STOR_TRANSPORT_GOOD;
}
if (srb->cmnd[0] == MODE_SELECT_10) {
US_DEBUGP("jumpshot_transport: Gah! MODE_SELECT_10.\n");
return USB_STOR_TRANSPORT_ERROR;
}
if (srb->cmnd[0] == READ_10) {
block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
((u32)(srb->cmnd[4]) << 8) | ((u32)(srb->cmnd[5]));
blocks = ((u32)(srb->cmnd[7]) << 8) | ((u32)(srb->cmnd[8]));
US_DEBUGP("jumpshot_transport: READ_10: read block 0x%04lx count %ld\n", block, blocks);
return jumpshot_read_data(us, info, block, blocks);
}
if (srb->cmnd[0] == READ_12) {
// I don't think we'll ever see a READ_12 but support it anyway...
//
block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
((u32)(srb->cmnd[4]) << 8) | ((u32)(srb->cmnd[5]));
blocks = ((u32)(srb->cmnd[6]) << 24) | ((u32)(srb->cmnd[7]) << 16) |
((u32)(srb->cmnd[8]) << 8) | ((u32)(srb->cmnd[9]));
US_DEBUGP("jumpshot_transport: READ_12: read block 0x%04lx count %ld\n", block, blocks);
return jumpshot_read_data(us, info, block, blocks);
}
if (srb->cmnd[0] == WRITE_10) {
block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
((u32)(srb->cmnd[4]) << 8) | ((u32)(srb->cmnd[5]));
blocks = ((u32)(srb->cmnd[7]) << 8) | ((u32)(srb->cmnd[8]));
US_DEBUGP("jumpshot_transport: WRITE_10: write block 0x%04lx count %ld\n", block, blocks);
return jumpshot_write_data(us, info, block, blocks);
}
if (srb->cmnd[0] == WRITE_12) {
// I don't think we'll ever see a WRITE_12 but support it anyway...
//
block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
((u32)(srb->cmnd[4]) << 8) | ((u32)(srb->cmnd[5]));
blocks = ((u32)(srb->cmnd[6]) << 24) | ((u32)(srb->cmnd[7]) << 16) |
((u32)(srb->cmnd[8]) << 8) | ((u32)(srb->cmnd[9]));
US_DEBUGP("jumpshot_transport: WRITE_12: write block 0x%04lx count %ld\n", block, blocks);
return jumpshot_write_data(us, info, block, blocks);
}
if (srb->cmnd[0] == TEST_UNIT_READY) {
US_DEBUGP("jumpshot_transport: TEST_UNIT_READY.\n");
return jumpshot_get_status(us);
}
if (srb->cmnd[0] == REQUEST_SENSE) {
US_DEBUGP("jumpshot_transport: REQUEST_SENSE.\n");
memset(ptr, 0, 18);
ptr[0] = 0xF0;
ptr[2] = info->sense_key;
ptr[7] = 11;
ptr[12] = info->sense_asc;
ptr[13] = info->sense_ascq;
usb_stor_set_xfer_buf(ptr, 18, srb);
return USB_STOR_TRANSPORT_GOOD;
}
if (srb->cmnd[0] == MODE_SENSE) {
US_DEBUGP("jumpshot_transport: MODE_SENSE_6 detected\n");
return jumpshot_handle_mode_sense(us, srb, 1);
}
if (srb->cmnd[0] == MODE_SENSE_10) {
US_DEBUGP("jumpshot_transport: MODE_SENSE_10 detected\n");
return jumpshot_handle_mode_sense(us, srb, 0);
}
if (srb->cmnd[0] == ALLOW_MEDIUM_REMOVAL) {
// sure. whatever. not like we can stop the user from popping
// the media out of the device (no locking doors, etc)
//
return USB_STOR_TRANSPORT_GOOD;
}
if (srb->cmnd[0] == START_STOP) {
/* this is used by sd.c'check_scsidisk_media_change to detect
media change */
US_DEBUGP("jumpshot_transport: START_STOP.\n");
/* the first jumpshot_id_device after a media change returns
an error (determined experimentally) */
rc = jumpshot_id_device(us, info);
if (rc == USB_STOR_TRANSPORT_GOOD) {
info->sense_key = NO_SENSE;
srb->result = SUCCESS;
} else {
info->sense_key = UNIT_ATTENTION;
srb->result = SAM_STAT_CHECK_CONDITION;
}
return rc;
}
US_DEBUGP("jumpshot_transport: Gah! Unknown command: %d (0x%x)\n",
srb->cmnd[0], srb->cmnd[0]);
info->sense_key = 0x05;
info->sense_asc = 0x20;
info->sense_ascq = 0x00;
return USB_STOR_TRANSPORT_FAILED;
}
static int jumpshot_probe(struct usb_interface *intf,
const struct usb_device_id *id)
{
struct us_data *us;
int result;
result = usb_stor_probe1(&us, intf, id,
(id - jumpshot_usb_ids) + jumpshot_unusual_dev_list);
if (result)
return result;
us->transport_name = "Lexar Jumpshot Control/Bulk";
us->transport = jumpshot_transport;
us->transport_reset = usb_stor_Bulk_reset;
us->max_lun = 1;
result = usb_stor_probe2(us);
return result;
}
static struct usb_driver jumpshot_driver = {
.name = "ums-jumpshot",
.probe = jumpshot_probe,
.disconnect = usb_stor_disconnect,
.suspend = usb_stor_suspend,
.resume = usb_stor_resume,
.reset_resume = usb_stor_reset_resume,
.pre_reset = usb_stor_pre_reset,
.post_reset = usb_stor_post_reset,
.id_table = jumpshot_usb_ids,
.soft_unbind = 1,
};
static int __init jumpshot_init(void)
{
return usb_register(&jumpshot_driver);
}
static void __exit jumpshot_exit(void)
{
usb_deregister(&jumpshot_driver);
}
module_init(jumpshot_init);
module_exit(jumpshot_exit);
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