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linux-next/drivers/cdrom/gdrom.c
Maurizio Lombardi 2bbea6e117 cdrom: do not call check_disk_change() inside cdrom_open()
when mounting an ISO filesystem sometimes (very rarely)
the system hangs because of a race condition between two tasks.

PID: 6766   TASK: ffff88007b2a6dd0  CPU: 0   COMMAND: "mount"
 #0 [ffff880078447ae0] __schedule at ffffffff8168d605
 #1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
 #2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
 #3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
 #4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
 #5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
 #6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
 #7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
 #8 [ffff880078447da8] mount_bdev at ffffffff81202570
 #9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
#10 [ffff880078447e28] mount_fs at ffffffff81202d09
#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
#12 [ffff880078447ea8] do_mount at ffffffff81220fee
#13 [ffff880078447f28] sys_mount at ffffffff812218d6
#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007fd9ea914e9a  RSP: 00007ffd5d9bf648  RFLAGS: 00010246
    RAX: 00000000000000a5  RBX: ffffffff81698c49  RCX: 0000000000000010
    RDX: 00007fd9ec2bc210  RSI: 00007fd9ec2bc290  RDI: 00007fd9ec2bcf30
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000010
    R10: 00000000c0ed0001  R11: 0000000000000206  R12: 00007fd9ec2bc040
    R13: 00007fd9eb6b2380  R14: 00007fd9ec2bc210  R15: 00007fd9ec2bcf30
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

This task was trying to mount the cdrom.  It allocated and configured a
super_block struct and owned the write-lock for the super_block->s_umount
rwsem. While exclusively owning the s_umount lock, it called
sr_block_ioctl and waited to acquire the global sr_mutex lock.

PID: 6785   TASK: ffff880078720fb0  CPU: 0   COMMAND: "systemd-udevd"
 #0 [ffff880078417898] __schedule at ffffffff8168d605
 #1 [ffff880078417900] schedule at ffffffff8168dc59
 #2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
 #3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
 #4 [ffff8800784179d0] down_read at ffffffff8168cde0
 #5 [ffff8800784179e8] get_super at ffffffff81201cc7
 #6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
 #7 [ffff880078417a40] flush_disk at ffffffff8123a94b
 #8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
 #9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
#16 [ffff880078417d00] do_last at ffffffff8120d53d
#17 [ffff880078417db0] path_openat at ffffffff8120e6b2
#18 [ffff880078417e48] do_filp_open at ffffffff8121082b
#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
#20 [ffff880078417f70] sys_open at ffffffff811fde4e
#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007f29438b0c20  RSP: 00007ffc76624b78  RFLAGS: 00010246
    RAX: 0000000000000002  RBX: ffffffff81698c49  RCX: 0000000000000000
    RDX: 00007f2944a5fa70  RSI: 00000000000a0800  RDI: 00007f2944a5fa70
    RBP: 00007f2944a5f540   R8: 0000000000000000   R9: 0000000000000020
    R10: 00007f2943614c40  R11: 0000000000000246  R12: ffffffff811fde4e
    R13: ffff880078417f78  R14: 000000000000000c  R15: 00007f2944a4b010
    ORIG_RAX: 0000000000000002  CS: 0033  SS: 002b

This task tried to open the cdrom device, the sr_block_open function
acquired the global sr_mutex lock. The call to check_disk_change()
then saw an event flag indicating a possible media change and tried
to flush any cached data for the device.
As part of the flush, it tried to acquire the super_block->s_umount
lock associated with the cdrom device.
This was the same super_block as created and locked by the previous task.

The first task acquires the s_umount lock and then the sr_mutex_lock;
the second task acquires the sr_mutex_lock and then the s_umount lock.

This patch fixes the issue by moving check_disk_change() out of
cdrom_open() and let the caller take care of it.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-03-09 08:06:35 -07:00

899 lines
23 KiB
C

/* GD ROM driver for the SEGA Dreamcast
* copyright Adrian McMenamin, 2007
* With thanks to Marcus Comstedt and Nathan Keynes
* for work in reversing PIO and DMA
*
* 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 of the License, 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>
#include <linux/cdrom.h>
#include <linux/genhd.h>
#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
#include <linux/platform_device.h>
#include <scsi/scsi.h>
#include <asm/io.h>
#include <asm/dma.h>
#include <asm/delay.h>
#include <mach/dma.h>
#include <mach/sysasic.h>
#define GDROM_DEV_NAME "gdrom"
#define GD_SESSION_OFFSET 150
/* GD Rom commands */
#define GDROM_COM_SOFTRESET 0x08
#define GDROM_COM_EXECDIAG 0x90
#define GDROM_COM_PACKET 0xA0
#define GDROM_COM_IDDEV 0xA1
/* GD Rom registers */
#define GDROM_BASE_REG 0xA05F7000
#define GDROM_ALTSTATUS_REG (GDROM_BASE_REG + 0x18)
#define GDROM_DATA_REG (GDROM_BASE_REG + 0x80)
#define GDROM_ERROR_REG (GDROM_BASE_REG + 0x84)
#define GDROM_INTSEC_REG (GDROM_BASE_REG + 0x88)
#define GDROM_SECNUM_REG (GDROM_BASE_REG + 0x8C)
#define GDROM_BCL_REG (GDROM_BASE_REG + 0x90)
#define GDROM_BCH_REG (GDROM_BASE_REG + 0x94)
#define GDROM_DSEL_REG (GDROM_BASE_REG + 0x98)
#define GDROM_STATUSCOMMAND_REG (GDROM_BASE_REG + 0x9C)
#define GDROM_RESET_REG (GDROM_BASE_REG + 0x4E4)
#define GDROM_DMA_STARTADDR_REG (GDROM_BASE_REG + 0x404)
#define GDROM_DMA_LENGTH_REG (GDROM_BASE_REG + 0x408)
#define GDROM_DMA_DIRECTION_REG (GDROM_BASE_REG + 0x40C)
#define GDROM_DMA_ENABLE_REG (GDROM_BASE_REG + 0x414)
#define GDROM_DMA_STATUS_REG (GDROM_BASE_REG + 0x418)
#define GDROM_DMA_WAIT_REG (GDROM_BASE_REG + 0x4A0)
#define GDROM_DMA_ACCESS_CTRL_REG (GDROM_BASE_REG + 0x4B8)
#define GDROM_HARD_SECTOR 2048
#define BLOCK_LAYER_SECTOR 512
#define GD_TO_BLK 4
#define GDROM_DEFAULT_TIMEOUT (HZ * 7)
static DEFINE_MUTEX(gdrom_mutex);
static const struct {
int sense_key;
const char * const text;
} sense_texts[] = {
{NO_SENSE, "OK"},
{RECOVERED_ERROR, "Recovered from error"},
{NOT_READY, "Device not ready"},
{MEDIUM_ERROR, "Disk not ready"},
{HARDWARE_ERROR, "Hardware error"},
{ILLEGAL_REQUEST, "Command has failed"},
{UNIT_ATTENTION, "Device needs attention - disk may have been changed"},
{DATA_PROTECT, "Data protection error"},
{ABORTED_COMMAND, "Command aborted"},
};
static struct platform_device *pd;
static int gdrom_major;
static DECLARE_WAIT_QUEUE_HEAD(command_queue);
static DECLARE_WAIT_QUEUE_HEAD(request_queue);
static DEFINE_SPINLOCK(gdrom_lock);
static void gdrom_readdisk_dma(struct work_struct *work);
static DECLARE_WORK(work, gdrom_readdisk_dma);
static LIST_HEAD(gdrom_deferred);
struct gdromtoc {
unsigned int entry[99];
unsigned int first, last;
unsigned int leadout;
};
static struct gdrom_unit {
struct gendisk *disk;
struct cdrom_device_info *cd_info;
int status;
int pending;
int transfer;
char disk_type;
struct gdromtoc *toc;
struct request_queue *gdrom_rq;
} gd;
struct gdrom_id {
char mid;
char modid;
char verid;
char padA[13];
char mname[16];
char modname[16];
char firmver[16];
char padB[16];
};
static int gdrom_getsense(short *bufstring);
static int gdrom_packetcommand(struct cdrom_device_info *cd_info,
struct packet_command *command);
static int gdrom_hardreset(struct cdrom_device_info *cd_info);
static bool gdrom_is_busy(void)
{
return (__raw_readb(GDROM_ALTSTATUS_REG) & 0x80) != 0;
}
static bool gdrom_data_request(void)
{
return (__raw_readb(GDROM_ALTSTATUS_REG) & 0x88) == 8;
}
static bool gdrom_wait_clrbusy(void)
{
unsigned long timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
while ((__raw_readb(GDROM_ALTSTATUS_REG) & 0x80) &&
(time_before(jiffies, timeout)))
cpu_relax();
return time_before(jiffies, timeout + 1);
}
static bool gdrom_wait_busy_sleeps(void)
{
unsigned long timeout;
/* Wait to get busy first */
timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
while (!gdrom_is_busy() && time_before(jiffies, timeout))
cpu_relax();
/* Now wait for busy to clear */
return gdrom_wait_clrbusy();
}
static void gdrom_identifydevice(void *buf)
{
int c;
short *data = buf;
/* If the device won't clear it has probably
* been hit by a serious failure - but we'll
* try to return a sense key even so */
if (!gdrom_wait_clrbusy()) {
gdrom_getsense(NULL);
return;
}
__raw_writeb(GDROM_COM_IDDEV, GDROM_STATUSCOMMAND_REG);
if (!gdrom_wait_busy_sleeps()) {
gdrom_getsense(NULL);
return;
}
/* now read in the data */
for (c = 0; c < 40; c++)
data[c] = __raw_readw(GDROM_DATA_REG);
}
static void gdrom_spicommand(void *spi_string, int buflen)
{
short *cmd = spi_string;
unsigned long timeout;
/* ensure IRQ_WAIT is set */
__raw_writeb(0x08, GDROM_ALTSTATUS_REG);
/* specify how many bytes we expect back */
__raw_writeb(buflen & 0xFF, GDROM_BCL_REG);
__raw_writeb((buflen >> 8) & 0xFF, GDROM_BCH_REG);
/* other parameters */
__raw_writeb(0, GDROM_INTSEC_REG);
__raw_writeb(0, GDROM_SECNUM_REG);
__raw_writeb(0, GDROM_ERROR_REG);
/* Wait until we can go */
if (!gdrom_wait_clrbusy()) {
gdrom_getsense(NULL);
return;
}
timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
__raw_writeb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
while (!gdrom_data_request() && time_before(jiffies, timeout))
cpu_relax();
if (!time_before(jiffies, timeout + 1)) {
gdrom_getsense(NULL);
return;
}
outsw(GDROM_DATA_REG, cmd, 6);
}
/* gdrom_command_executediagnostic:
* Used to probe for presence of working GDROM
* Restarts GDROM device and then applies standard ATA 3
* Execute Diagnostic Command: a return of '1' indicates device 0
* present and device 1 absent
*/
static char gdrom_execute_diagnostic(void)
{
gdrom_hardreset(gd.cd_info);
if (!gdrom_wait_clrbusy())
return 0;
__raw_writeb(GDROM_COM_EXECDIAG, GDROM_STATUSCOMMAND_REG);
if (!gdrom_wait_busy_sleeps())
return 0;
return __raw_readb(GDROM_ERROR_REG);
}
/*
* Prepare disk command
* byte 0 = 0x70
* byte 1 = 0x1f
*/
static int gdrom_preparedisk_cmd(void)
{
struct packet_command *spin_command;
spin_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
if (!spin_command)
return -ENOMEM;
spin_command->cmd[0] = 0x70;
spin_command->cmd[2] = 0x1f;
spin_command->buflen = 0;
gd.pending = 1;
gdrom_packetcommand(gd.cd_info, spin_command);
/* 60 second timeout */
wait_event_interruptible_timeout(command_queue, gd.pending == 0,
GDROM_DEFAULT_TIMEOUT);
gd.pending = 0;
kfree(spin_command);
if (gd.status & 0x01) {
/* log an error */
gdrom_getsense(NULL);
return -EIO;
}
return 0;
}
/*
* Read TOC command
* byte 0 = 0x14
* byte 1 = session
* byte 3 = sizeof TOC >> 8 ie upper byte
* byte 4 = sizeof TOC & 0xff ie lower byte
*/
static int gdrom_readtoc_cmd(struct gdromtoc *toc, int session)
{
int tocsize;
struct packet_command *toc_command;
int err = 0;
toc_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
if (!toc_command)
return -ENOMEM;
tocsize = sizeof(struct gdromtoc);
toc_command->cmd[0] = 0x14;
toc_command->cmd[1] = session;
toc_command->cmd[3] = tocsize >> 8;
toc_command->cmd[4] = tocsize & 0xff;
toc_command->buflen = tocsize;
if (gd.pending) {
err = -EBUSY;
goto cleanup_readtoc_final;
}
gd.pending = 1;
gdrom_packetcommand(gd.cd_info, toc_command);
wait_event_interruptible_timeout(command_queue, gd.pending == 0,
GDROM_DEFAULT_TIMEOUT);
if (gd.pending) {
err = -EINVAL;
goto cleanup_readtoc;
}
insw(GDROM_DATA_REG, toc, tocsize/2);
if (gd.status & 0x01)
err = -EINVAL;
cleanup_readtoc:
gd.pending = 0;
cleanup_readtoc_final:
kfree(toc_command);
return err;
}
/* TOC helpers */
static int get_entry_lba(int track)
{
return (cpu_to_be32(track & 0xffffff00) - GD_SESSION_OFFSET);
}
static int get_entry_q_ctrl(int track)
{
return (track & 0x000000f0) >> 4;
}
static int get_entry_track(int track)
{
return (track & 0x0000ff00) >> 8;
}
static int gdrom_get_last_session(struct cdrom_device_info *cd_info,
struct cdrom_multisession *ms_info)
{
int fentry, lentry, track, data, tocuse, err;
if (!gd.toc)
return -ENOMEM;
tocuse = 1;
/* Check if GD-ROM */
err = gdrom_readtoc_cmd(gd.toc, 1);
/* Not a GD-ROM so check if standard CD-ROM */
if (err) {
tocuse = 0;
err = gdrom_readtoc_cmd(gd.toc, 0);
if (err) {
pr_info("Could not get CD table of contents\n");
return -ENXIO;
}
}
fentry = get_entry_track(gd.toc->first);
lentry = get_entry_track(gd.toc->last);
/* Find the first data track */
track = get_entry_track(gd.toc->last);
do {
data = gd.toc->entry[track - 1];
if (get_entry_q_ctrl(data))
break; /* ie a real data track */
track--;
} while (track >= fentry);
if ((track > 100) || (track < get_entry_track(gd.toc->first))) {
pr_info("No data on the last session of the CD\n");
gdrom_getsense(NULL);
return -ENXIO;
}
ms_info->addr_format = CDROM_LBA;
ms_info->addr.lba = get_entry_lba(data);
ms_info->xa_flag = 1;
return 0;
}
static int gdrom_open(struct cdrom_device_info *cd_info, int purpose)
{
/* spin up the disk */
return gdrom_preparedisk_cmd();
}
/* this function is required even if empty */
static void gdrom_release(struct cdrom_device_info *cd_info)
{
}
static int gdrom_drivestatus(struct cdrom_device_info *cd_info, int ignore)
{
/* read the sense key */
char sense = __raw_readb(GDROM_ERROR_REG);
sense &= 0xF0;
if (sense == 0)
return CDS_DISC_OK;
if (sense == 0x20)
return CDS_DRIVE_NOT_READY;
/* default */
return CDS_NO_INFO;
}
static unsigned int gdrom_check_events(struct cdrom_device_info *cd_info,
unsigned int clearing, int ignore)
{
/* check the sense key */
return (__raw_readb(GDROM_ERROR_REG) & 0xF0) == 0x60 ?
DISK_EVENT_MEDIA_CHANGE : 0;
}
/* reset the G1 bus */
static int gdrom_hardreset(struct cdrom_device_info *cd_info)
{
int count;
__raw_writel(0x1fffff, GDROM_RESET_REG);
for (count = 0xa0000000; count < 0xa0200000; count += 4)
__raw_readl(count);
return 0;
}
/* keep the function looking like the universal
* CD Rom specification - returning int */
static int gdrom_packetcommand(struct cdrom_device_info *cd_info,
struct packet_command *command)
{
gdrom_spicommand(&command->cmd, command->buflen);
return 0;
}
/* Get Sense SPI command
* From Marcus Comstedt
* cmd = 0x13
* cmd + 4 = length of returned buffer
* Returns 5 16 bit words
*/
static int gdrom_getsense(short *bufstring)
{
struct packet_command *sense_command;
short sense[5];
int sense_key;
int err = -EIO;
sense_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
if (!sense_command)
return -ENOMEM;
sense_command->cmd[0] = 0x13;
sense_command->cmd[4] = 10;
sense_command->buflen = 10;
/* even if something is pending try to get
* the sense key if possible */
if (gd.pending && !gdrom_wait_clrbusy()) {
err = -EBUSY;
goto cleanup_sense_final;
}
gd.pending = 1;
gdrom_packetcommand(gd.cd_info, sense_command);
wait_event_interruptible_timeout(command_queue, gd.pending == 0,
GDROM_DEFAULT_TIMEOUT);
if (gd.pending)
goto cleanup_sense;
insw(GDROM_DATA_REG, &sense, sense_command->buflen/2);
if (sense[1] & 40) {
pr_info("Drive not ready - command aborted\n");
goto cleanup_sense;
}
sense_key = sense[1] & 0x0F;
if (sense_key < ARRAY_SIZE(sense_texts))
pr_info("%s\n", sense_texts[sense_key].text);
else
pr_err("Unknown sense key: %d\n", sense_key);
if (bufstring) /* return addional sense data */
memcpy(bufstring, &sense[4], 2);
if (sense_key < 2)
err = 0;
cleanup_sense:
gd.pending = 0;
cleanup_sense_final:
kfree(sense_command);
return err;
}
static int gdrom_audio_ioctl(struct cdrom_device_info *cdi, unsigned int cmd,
void *arg)
{
return -EINVAL;
}
static const struct cdrom_device_ops gdrom_ops = {
.open = gdrom_open,
.release = gdrom_release,
.drive_status = gdrom_drivestatus,
.check_events = gdrom_check_events,
.get_last_session = gdrom_get_last_session,
.reset = gdrom_hardreset,
.audio_ioctl = gdrom_audio_ioctl,
.generic_packet = cdrom_dummy_generic_packet,
.capability = CDC_MULTI_SESSION | CDC_MEDIA_CHANGED |
CDC_RESET | CDC_DRIVE_STATUS | CDC_CD_R,
};
static int gdrom_bdops_open(struct block_device *bdev, fmode_t mode)
{
int ret;
check_disk_change(bdev);
mutex_lock(&gdrom_mutex);
ret = cdrom_open(gd.cd_info, bdev, mode);
mutex_unlock(&gdrom_mutex);
return ret;
}
static void gdrom_bdops_release(struct gendisk *disk, fmode_t mode)
{
mutex_lock(&gdrom_mutex);
cdrom_release(gd.cd_info, mode);
mutex_unlock(&gdrom_mutex);
}
static unsigned int gdrom_bdops_check_events(struct gendisk *disk,
unsigned int clearing)
{
return cdrom_check_events(gd.cd_info, clearing);
}
static int gdrom_bdops_ioctl(struct block_device *bdev, fmode_t mode,
unsigned cmd, unsigned long arg)
{
int ret;
mutex_lock(&gdrom_mutex);
ret = cdrom_ioctl(gd.cd_info, bdev, mode, cmd, arg);
mutex_unlock(&gdrom_mutex);
return ret;
}
static const struct block_device_operations gdrom_bdops = {
.owner = THIS_MODULE,
.open = gdrom_bdops_open,
.release = gdrom_bdops_release,
.check_events = gdrom_bdops_check_events,
.ioctl = gdrom_bdops_ioctl,
};
static irqreturn_t gdrom_command_interrupt(int irq, void *dev_id)
{
gd.status = __raw_readb(GDROM_STATUSCOMMAND_REG);
if (gd.pending != 1)
return IRQ_HANDLED;
gd.pending = 0;
wake_up_interruptible(&command_queue);
return IRQ_HANDLED;
}
static irqreturn_t gdrom_dma_interrupt(int irq, void *dev_id)
{
gd.status = __raw_readb(GDROM_STATUSCOMMAND_REG);
if (gd.transfer != 1)
return IRQ_HANDLED;
gd.transfer = 0;
wake_up_interruptible(&request_queue);
return IRQ_HANDLED;
}
static int gdrom_set_interrupt_handlers(void)
{
int err;
err = request_irq(HW_EVENT_GDROM_CMD, gdrom_command_interrupt,
0, "gdrom_command", &gd);
if (err)
return err;
err = request_irq(HW_EVENT_GDROM_DMA, gdrom_dma_interrupt,
0, "gdrom_dma", &gd);
if (err)
free_irq(HW_EVENT_GDROM_CMD, &gd);
return err;
}
/* Implement DMA read using SPI command
* 0 -> 0x30
* 1 -> mode
* 2 -> block >> 16
* 3 -> block >> 8
* 4 -> block
* 8 -> sectors >> 16
* 9 -> sectors >> 8
* 10 -> sectors
*/
static void gdrom_readdisk_dma(struct work_struct *work)
{
int block, block_cnt;
blk_status_t err;
struct packet_command *read_command;
struct list_head *elem, *next;
struct request *req;
unsigned long timeout;
if (list_empty(&gdrom_deferred))
return;
read_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
if (!read_command)
return; /* get more memory later? */
read_command->cmd[0] = 0x30;
read_command->cmd[1] = 0x20;
spin_lock(&gdrom_lock);
list_for_each_safe(elem, next, &gdrom_deferred) {
req = list_entry(elem, struct request, queuelist);
spin_unlock(&gdrom_lock);
block = blk_rq_pos(req)/GD_TO_BLK + GD_SESSION_OFFSET;
block_cnt = blk_rq_sectors(req)/GD_TO_BLK;
__raw_writel(virt_to_phys(bio_data(req->bio)), GDROM_DMA_STARTADDR_REG);
__raw_writel(block_cnt * GDROM_HARD_SECTOR, GDROM_DMA_LENGTH_REG);
__raw_writel(1, GDROM_DMA_DIRECTION_REG);
__raw_writel(1, GDROM_DMA_ENABLE_REG);
read_command->cmd[2] = (block >> 16) & 0xFF;
read_command->cmd[3] = (block >> 8) & 0xFF;
read_command->cmd[4] = block & 0xFF;
read_command->cmd[8] = (block_cnt >> 16) & 0xFF;
read_command->cmd[9] = (block_cnt >> 8) & 0xFF;
read_command->cmd[10] = block_cnt & 0xFF;
/* set for DMA */
__raw_writeb(1, GDROM_ERROR_REG);
/* other registers */
__raw_writeb(0, GDROM_SECNUM_REG);
__raw_writeb(0, GDROM_BCL_REG);
__raw_writeb(0, GDROM_BCH_REG);
__raw_writeb(0, GDROM_DSEL_REG);
__raw_writeb(0, GDROM_INTSEC_REG);
/* Wait for registers to reset after any previous activity */
timeout = jiffies + HZ / 2;
while (gdrom_is_busy() && time_before(jiffies, timeout))
cpu_relax();
__raw_writeb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
timeout = jiffies + HZ / 2;
/* Wait for packet command to finish */
while (gdrom_is_busy() && time_before(jiffies, timeout))
cpu_relax();
gd.pending = 1;
gd.transfer = 1;
outsw(GDROM_DATA_REG, &read_command->cmd, 6);
timeout = jiffies + HZ / 2;
/* Wait for any pending DMA to finish */
while (__raw_readb(GDROM_DMA_STATUS_REG) &&
time_before(jiffies, timeout))
cpu_relax();
/* start transfer */
__raw_writeb(1, GDROM_DMA_STATUS_REG);
wait_event_interruptible_timeout(request_queue,
gd.transfer == 0, GDROM_DEFAULT_TIMEOUT);
err = gd.transfer ? BLK_STS_IOERR : BLK_STS_OK;
gd.transfer = 0;
gd.pending = 0;
/* now seek to take the request spinlock
* before handling ending the request */
spin_lock(&gdrom_lock);
list_del_init(&req->queuelist);
__blk_end_request_all(req, err);
}
spin_unlock(&gdrom_lock);
kfree(read_command);
}
static void gdrom_request(struct request_queue *rq)
{
struct request *req;
while ((req = blk_fetch_request(rq)) != NULL) {
switch (req_op(req)) {
case REQ_OP_READ:
/*
* Add to list of deferred work and then schedule
* workqueue.
*/
list_add_tail(&req->queuelist, &gdrom_deferred);
schedule_work(&work);
break;
case REQ_OP_WRITE:
pr_notice("Read only device - write request ignored\n");
__blk_end_request_all(req, BLK_STS_IOERR);
break;
default:
printk(KERN_DEBUG "gdrom: Non-fs request ignored\n");
__blk_end_request_all(req, BLK_STS_IOERR);
break;
}
}
}
/* Print string identifying GD ROM device */
static int gdrom_outputversion(void)
{
struct gdrom_id *id;
char *model_name, *manuf_name, *firmw_ver;
int err = -ENOMEM;
/* query device ID */
id = kzalloc(sizeof(struct gdrom_id), GFP_KERNEL);
if (!id)
return err;
gdrom_identifydevice(id);
model_name = kstrndup(id->modname, 16, GFP_KERNEL);
if (!model_name)
goto free_id;
manuf_name = kstrndup(id->mname, 16, GFP_KERNEL);
if (!manuf_name)
goto free_model_name;
firmw_ver = kstrndup(id->firmver, 16, GFP_KERNEL);
if (!firmw_ver)
goto free_manuf_name;
pr_info("%s from %s with firmware %s\n",
model_name, manuf_name, firmw_ver);
err = 0;
kfree(firmw_ver);
free_manuf_name:
kfree(manuf_name);
free_model_name:
kfree(model_name);
free_id:
kfree(id);
return err;
}
/* set the default mode for DMA transfer */
static int gdrom_init_dma_mode(void)
{
__raw_writeb(0x13, GDROM_ERROR_REG);
__raw_writeb(0x22, GDROM_INTSEC_REG);
if (!gdrom_wait_clrbusy())
return -EBUSY;
__raw_writeb(0xEF, GDROM_STATUSCOMMAND_REG);
if (!gdrom_wait_busy_sleeps())
return -EBUSY;
/* Memory protection setting for GDROM DMA
* Bits 31 - 16 security: 0x8843
* Bits 15 and 7 reserved (0)
* Bits 14 - 8 start of transfer range in 1 MB blocks OR'ed with 0x80
* Bits 6 - 0 end of transfer range in 1 MB blocks OR'ed with 0x80
* (0x40 | 0x80) = start range at 0x0C000000
* (0x7F | 0x80) = end range at 0x0FFFFFFF */
__raw_writel(0x8843407F, GDROM_DMA_ACCESS_CTRL_REG);
__raw_writel(9, GDROM_DMA_WAIT_REG); /* DMA word setting */
return 0;
}
static void probe_gdrom_setupcd(void)
{
gd.cd_info->ops = &gdrom_ops;
gd.cd_info->capacity = 1;
strcpy(gd.cd_info->name, GDROM_DEV_NAME);
gd.cd_info->mask = CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|
CDC_SELECT_DISC;
}
static void probe_gdrom_setupdisk(void)
{
gd.disk->major = gdrom_major;
gd.disk->first_minor = 1;
gd.disk->minors = 1;
strcpy(gd.disk->disk_name, GDROM_DEV_NAME);
}
static int probe_gdrom_setupqueue(void)
{
blk_queue_logical_block_size(gd.gdrom_rq, GDROM_HARD_SECTOR);
/* using DMA so memory will need to be contiguous */
blk_queue_max_segments(gd.gdrom_rq, 1);
/* set a large max size to get most from DMA */
blk_queue_max_segment_size(gd.gdrom_rq, 0x40000);
gd.disk->queue = gd.gdrom_rq;
return gdrom_init_dma_mode();
}
/*
* register this as a block device and as compliant with the
* universal CD Rom driver interface
*/
static int probe_gdrom(struct platform_device *devptr)
{
int err;
/* Start the device */
if (gdrom_execute_diagnostic() != 1) {
pr_warning("ATA Probe for GDROM failed\n");
return -ENODEV;
}
/* Print out firmware ID */
if (gdrom_outputversion())
return -ENOMEM;
/* Register GDROM */
gdrom_major = register_blkdev(0, GDROM_DEV_NAME);
if (gdrom_major <= 0)
return gdrom_major;
pr_info("Registered with major number %d\n",
gdrom_major);
/* Specify basic properties of drive */
gd.cd_info = kzalloc(sizeof(struct cdrom_device_info), GFP_KERNEL);
if (!gd.cd_info) {
err = -ENOMEM;
goto probe_fail_no_mem;
}
probe_gdrom_setupcd();
gd.disk = alloc_disk(1);
if (!gd.disk) {
err = -ENODEV;
goto probe_fail_no_disk;
}
probe_gdrom_setupdisk();
if (register_cdrom(gd.cd_info)) {
err = -ENODEV;
goto probe_fail_cdrom_register;
}
gd.disk->fops = &gdrom_bdops;
/* latch on to the interrupt */
err = gdrom_set_interrupt_handlers();
if (err)
goto probe_fail_cmdirq_register;
gd.gdrom_rq = blk_init_queue(gdrom_request, &gdrom_lock);
if (!gd.gdrom_rq) {
err = -ENOMEM;
goto probe_fail_requestq;
}
blk_queue_bounce_limit(gd.gdrom_rq, BLK_BOUNCE_HIGH);
err = probe_gdrom_setupqueue();
if (err)
goto probe_fail_toc;
gd.toc = kzalloc(sizeof(struct gdromtoc), GFP_KERNEL);
if (!gd.toc) {
err = -ENOMEM;
goto probe_fail_toc;
}
add_disk(gd.disk);
return 0;
probe_fail_toc:
blk_cleanup_queue(gd.gdrom_rq);
probe_fail_requestq:
free_irq(HW_EVENT_GDROM_DMA, &gd);
free_irq(HW_EVENT_GDROM_CMD, &gd);
probe_fail_cmdirq_register:
probe_fail_cdrom_register:
del_gendisk(gd.disk);
probe_fail_no_disk:
kfree(gd.cd_info);
probe_fail_no_mem:
unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
gdrom_major = 0;
pr_warning("Probe failed - error is 0x%X\n", err);
return err;
}
static int remove_gdrom(struct platform_device *devptr)
{
flush_work(&work);
blk_cleanup_queue(gd.gdrom_rq);
free_irq(HW_EVENT_GDROM_CMD, &gd);
free_irq(HW_EVENT_GDROM_DMA, &gd);
del_gendisk(gd.disk);
if (gdrom_major)
unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
unregister_cdrom(gd.cd_info);
return 0;
}
static struct platform_driver gdrom_driver = {
.probe = probe_gdrom,
.remove = remove_gdrom,
.driver = {
.name = GDROM_DEV_NAME,
},
};
static int __init init_gdrom(void)
{
int rc;
gd.toc = NULL;
rc = platform_driver_register(&gdrom_driver);
if (rc)
return rc;
pd = platform_device_register_simple(GDROM_DEV_NAME, -1, NULL, 0);
if (IS_ERR(pd)) {
platform_driver_unregister(&gdrom_driver);
return PTR_ERR(pd);
}
return 0;
}
static void __exit exit_gdrom(void)
{
platform_device_unregister(pd);
platform_driver_unregister(&gdrom_driver);
kfree(gd.toc);
}
module_init(init_gdrom);
module_exit(exit_gdrom);
MODULE_AUTHOR("Adrian McMenamin <adrian@mcmen.demon.co.uk>");
MODULE_DESCRIPTION("SEGA Dreamcast GD-ROM Driver");
MODULE_LICENSE("GPL");