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linux-zen-server/drivers/scsi/vhba/vhba.c

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2023-08-30 17:53:23 +02:00
/*
* vhba.c
*
* Copyright (C) 2007-2012 Chia-I Wu <olvaffe AT gmail DOT com>
*
* 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) "vhba: " fmt
#include <linux/version.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/highmem.h>
#include <linux/fs.h>
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
#include <linux/sched/signal.h>
#else
#include <linux/sched.h>
#endif
#include <linux/platform_device.h>
#include <linux/miscdevice.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/scatterlist.h>
#ifdef CONFIG_COMPAT
#include <linux/compat.h>
#endif
#include <asm/uaccess.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_tcq.h>
MODULE_AUTHOR("Chia-I Wu");
MODULE_VERSION(VHBA_VERSION);
MODULE_DESCRIPTION("Virtual SCSI HBA");
MODULE_LICENSE("GPL");
#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 15, 0)
#define sdev_dbg(sdev, fmt, a...) \
dev_dbg(&(sdev)->sdev_gendev, fmt, ##a)
#define scmd_dbg(scmd, fmt, a...) \
dev_dbg(&(scmd)->device->sdev_gendev, fmt, ##a)
#endif
#define VHBA_MAX_SECTORS_PER_IO 256
#define VHBA_MAX_BUS 16
#define VHBA_MAX_ID 16
#define VHBA_MAX_DEVICES (VHBA_MAX_BUS * (VHBA_MAX_ID-1))
#define VHBA_KBUF_SIZE PAGE_SIZE
#define DATA_TO_DEVICE(dir) ((dir) == DMA_TO_DEVICE || (dir) == DMA_BIDIRECTIONAL)
#define DATA_FROM_DEVICE(dir) ((dir) == DMA_FROM_DEVICE || (dir) == DMA_BIDIRECTIONAL)
static int vhba_can_queue = 32;
module_param_named(can_queue, vhba_can_queue, int, 0);
enum vhba_req_state {
VHBA_REQ_FREE,
VHBA_REQ_PENDING,
VHBA_REQ_READING,
VHBA_REQ_SENT,
VHBA_REQ_WRITING,
};
struct vhba_command {
struct scsi_cmnd *cmd;
/* metatags are per-host. not to be confused with
queue tags that are usually per-lun */
unsigned long metatag;
int status;
struct list_head entry;
};
struct vhba_device {
unsigned int num;
spinlock_t cmd_lock;
struct list_head cmd_list;
wait_queue_head_t cmd_wq;
atomic_t refcnt;
unsigned char *kbuf;
size_t kbuf_size;
};
struct vhba_host {
struct Scsi_Host *shost;
spinlock_t cmd_lock;
int cmd_next;
struct vhba_command *commands;
spinlock_t dev_lock;
struct vhba_device *devices[VHBA_MAX_DEVICES];
int num_devices;
DECLARE_BITMAP(chgmap, VHBA_MAX_DEVICES);
int chgtype[VHBA_MAX_DEVICES];
struct work_struct scan_devices;
};
#define MAX_COMMAND_SIZE 16
struct vhba_request {
__u32 metatag;
__u32 lun;
__u8 cdb[MAX_COMMAND_SIZE];
__u8 cdb_len;
__u32 data_len;
};
struct vhba_response {
__u32 metatag;
__u32 status;
__u32 data_len;
};
struct vhba_command *vhba_alloc_command (void);
void vhba_free_command (struct vhba_command *vcmd);
static struct platform_device vhba_platform_device;
/* These functions define a symmetric 1:1 mapping between device numbers and
the bus and id. We have reserved the last id per bus for the host itself. */
void devnum_to_bus_and_id(unsigned int devnum, unsigned int *bus, unsigned int *id)
{
*bus = devnum / (VHBA_MAX_ID-1);
*id = devnum % (VHBA_MAX_ID-1);
}
unsigned int bus_and_id_to_devnum(unsigned int bus, unsigned int id)
{
return (bus * (VHBA_MAX_ID-1)) + id;
}
struct vhba_device *vhba_device_alloc (void)
{
struct vhba_device *vdev;
vdev = kzalloc(sizeof(struct vhba_device), GFP_KERNEL);
if (!vdev) {
return NULL;
}
spin_lock_init(&vdev->cmd_lock);
INIT_LIST_HEAD(&vdev->cmd_list);
init_waitqueue_head(&vdev->cmd_wq);
atomic_set(&vdev->refcnt, 1);
vdev->kbuf = NULL;
vdev->kbuf_size = 0;
return vdev;
}
void vhba_device_put (struct vhba_device *vdev)
{
if (atomic_dec_and_test(&vdev->refcnt)) {
kfree(vdev);
}
}
struct vhba_device *vhba_device_get (struct vhba_device *vdev)
{
atomic_inc(&vdev->refcnt);
return vdev;
}
int vhba_device_queue (struct vhba_device *vdev, struct scsi_cmnd *cmd)
{
struct vhba_host *vhost;
struct vhba_command *vcmd;
unsigned long flags;
vhost = platform_get_drvdata(&vhba_platform_device);
vcmd = vhba_alloc_command();
if (!vcmd) {
return SCSI_MLQUEUE_HOST_BUSY;
}
vcmd->cmd = cmd;
spin_lock_irqsave(&vdev->cmd_lock, flags);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 15, 0)
vcmd->metatag = scsi_cmd_to_rq(vcmd->cmd)->tag;
#else
vcmd->metatag = vcmd->cmd->request->tag;
#endif
list_add_tail(&vcmd->entry, &vdev->cmd_list);
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
wake_up_interruptible(&vdev->cmd_wq);
return 0;
}
int vhba_device_dequeue (struct vhba_device *vdev, struct scsi_cmnd *cmd)
{
struct vhba_command *vcmd;
int retval;
unsigned long flags;
spin_lock_irqsave(&vdev->cmd_lock, flags);
list_for_each_entry(vcmd, &vdev->cmd_list, entry) {
if (vcmd->cmd == cmd) {
list_del_init(&vcmd->entry);
break;
}
}
/* command not found */
if (&vcmd->entry == &vdev->cmd_list) {
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
return SUCCESS;
}
while (vcmd->status == VHBA_REQ_READING || vcmd->status == VHBA_REQ_WRITING) {
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
scmd_dbg(cmd, "wait for I/O before aborting\n");
schedule_timeout(1);
spin_lock_irqsave(&vdev->cmd_lock, flags);
}
retval = (vcmd->status == VHBA_REQ_SENT) ? FAILED : SUCCESS;
vhba_free_command(vcmd);
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
return retval;
}
#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 19, 0)
int vhba_slave_alloc(struct scsi_device *sdev)
{
struct Scsi_Host *shost = sdev->host;
sdev_dbg(sdev, "enabling tagging (queue depth: %i).\n", sdev->queue_depth);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 17, 0)
if (!shost_use_blk_mq(shost) && shost->bqt) {
#else
if (shost->bqt) {
#endif
blk_queue_init_tags(sdev->request_queue, sdev->queue_depth, shost->bqt);
}
scsi_adjust_queue_depth(sdev, 0, sdev->queue_depth);
return 0;
}
#endif
void vhba_scan_devices_add (struct vhba_host *vhost, int bus, int id)
{
struct scsi_device *sdev;
sdev = scsi_device_lookup(vhost->shost, bus, id, 0);
if (!sdev) {
scsi_add_device(vhost->shost, bus, id, 0);
} else {
dev_warn(&vhost->shost->shost_gendev, "tried to add an already-existing device %d:%d:0!\n", bus, id);
scsi_device_put(sdev);
}
}
void vhba_scan_devices_remove (struct vhba_host *vhost, int bus, int id)
{
struct scsi_device *sdev;
sdev = scsi_device_lookup(vhost->shost, bus, id, 0);
if (sdev) {
scsi_remove_device(sdev);
scsi_device_put(sdev);
} else {
dev_warn(&vhost->shost->shost_gendev, "tried to remove non-existing device %d:%d:0!\n", bus, id);
}
}
void vhba_scan_devices (struct work_struct *work)
{
struct vhba_host *vhost = container_of(work, struct vhba_host, scan_devices);
unsigned long flags;
int change, exists;
unsigned int devnum;
unsigned int bus, id;
for (;;) {
spin_lock_irqsave(&vhost->dev_lock, flags);
devnum = find_first_bit(vhost->chgmap, VHBA_MAX_DEVICES);
if (devnum >= VHBA_MAX_DEVICES) {
spin_unlock_irqrestore(&vhost->dev_lock, flags);
break;
}
change = vhost->chgtype[devnum];
exists = vhost->devices[devnum] != NULL;
vhost->chgtype[devnum] = 0;
clear_bit(devnum, vhost->chgmap);
spin_unlock_irqrestore(&vhost->dev_lock, flags);
devnum_to_bus_and_id(devnum, &bus, &id);
if (change < 0) {
dev_dbg(&vhost->shost->shost_gendev, "trying to remove target %d:%d:0\n", bus, id);
vhba_scan_devices_remove(vhost, bus, id);
} else if (change > 0) {
dev_dbg(&vhost->shost->shost_gendev, "trying to add target %d:%d:0\n", bus, id);
vhba_scan_devices_add(vhost, bus, id);
} else {
/* quick sequence of add/remove or remove/add; we determine
which one it was by checking if device structure exists */
if (exists) {
/* remove followed by add: remove and (re)add */
dev_dbg(&vhost->shost->shost_gendev, "trying to (re)add target %d:%d:0\n", bus, id);
vhba_scan_devices_remove(vhost, bus, id);
vhba_scan_devices_add(vhost, bus, id);
} else {
/* add followed by remove: no-op */
dev_dbg(&vhost->shost->shost_gendev, "no-op for target %d:%d:0\n", bus, id);
}
}
}
}
int vhba_add_device (struct vhba_device *vdev)
{
struct vhba_host *vhost;
unsigned int devnum;
unsigned long flags;
vhost = platform_get_drvdata(&vhba_platform_device);
vhba_device_get(vdev);
spin_lock_irqsave(&vhost->dev_lock, flags);
if (vhost->num_devices >= VHBA_MAX_DEVICES) {
spin_unlock_irqrestore(&vhost->dev_lock, flags);
vhba_device_put(vdev);
return -EBUSY;
}
for (devnum = 0; devnum < VHBA_MAX_DEVICES; devnum++) {
if (vhost->devices[devnum] == NULL) {
vdev->num = devnum;
vhost->devices[devnum] = vdev;
vhost->num_devices++;
set_bit(devnum, vhost->chgmap);
vhost->chgtype[devnum]++;
break;
}
}
spin_unlock_irqrestore(&vhost->dev_lock, flags);
schedule_work(&vhost->scan_devices);
return 0;
}
int vhba_remove_device (struct vhba_device *vdev)
{
struct vhba_host *vhost;
unsigned long flags;
vhost = platform_get_drvdata(&vhba_platform_device);
spin_lock_irqsave(&vhost->dev_lock, flags);
set_bit(vdev->num, vhost->chgmap);
vhost->chgtype[vdev->num]--;
vhost->devices[vdev->num] = NULL;
vhost->num_devices--;
spin_unlock_irqrestore(&vhost->dev_lock, flags);
vhba_device_put(vdev);
schedule_work(&vhost->scan_devices);
return 0;
}
struct vhba_device *vhba_lookup_device (int devnum)
{
struct vhba_host *vhost;
struct vhba_device *vdev = NULL;
unsigned long flags;
vhost = platform_get_drvdata(&vhba_platform_device);
if (likely(devnum < VHBA_MAX_DEVICES)) {
spin_lock_irqsave(&vhost->dev_lock, flags);
vdev = vhost->devices[devnum];
if (vdev) {
vdev = vhba_device_get(vdev);
}
spin_unlock_irqrestore(&vhost->dev_lock, flags);
}
return vdev;
}
struct vhba_command *vhba_alloc_command (void)
{
struct vhba_host *vhost;
struct vhba_command *vcmd;
unsigned long flags;
int i;
vhost = platform_get_drvdata(&vhba_platform_device);
spin_lock_irqsave(&vhost->cmd_lock, flags);
vcmd = vhost->commands + vhost->cmd_next++;
if (vcmd->status != VHBA_REQ_FREE) {
for (i = 0; i < vhba_can_queue; i++) {
vcmd = vhost->commands + i;
if (vcmd->status == VHBA_REQ_FREE) {
vhost->cmd_next = i + 1;
break;
}
}
if (i == vhba_can_queue) {
vcmd = NULL;
}
}
if (vcmd) {
vcmd->status = VHBA_REQ_PENDING;
}
vhost->cmd_next %= vhba_can_queue;
spin_unlock_irqrestore(&vhost->cmd_lock, flags);
return vcmd;
}
void vhba_free_command (struct vhba_command *vcmd)
{
struct vhba_host *vhost;
unsigned long flags;
vhost = platform_get_drvdata(&vhba_platform_device);
spin_lock_irqsave(&vhost->cmd_lock, flags);
vcmd->status = VHBA_REQ_FREE;
spin_unlock_irqrestore(&vhost->cmd_lock, flags);
}
int vhba_queuecommand (struct Scsi_Host *shost, struct scsi_cmnd *cmd)
{
struct vhba_device *vdev;
int retval;
unsigned int devnum;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 15, 0)
scmd_dbg(cmd, "queue %p tag %i\n", cmd, scsi_cmd_to_rq(cmd)->tag);
#else
scmd_dbg(cmd, "queue %p tag %i\n", cmd, cmd->request->tag);
#endif
devnum = bus_and_id_to_devnum(cmd->device->channel, cmd->device->id);
vdev = vhba_lookup_device(devnum);
if (!vdev) {
scmd_dbg(cmd, "no such device\n");
cmd->result = DID_NO_CONNECT << 16;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
scsi_done(cmd);
#else
cmd->scsi_done(cmd);
#endif
return 0;
}
retval = vhba_device_queue(vdev, cmd);
vhba_device_put(vdev);
return retval;
}
int vhba_abort (struct scsi_cmnd *cmd)
{
struct vhba_device *vdev;
int retval = SUCCESS;
unsigned int devnum;
scmd_dbg(cmd, "abort %p\n", cmd);
devnum = bus_and_id_to_devnum(cmd->device->channel, cmd->device->id);
vdev = vhba_lookup_device(devnum);
if (vdev) {
retval = vhba_device_dequeue(vdev, cmd);
vhba_device_put(vdev);
} else {
cmd->result = DID_NO_CONNECT << 16;
}
return retval;
}
static struct scsi_host_template vhba_template = {
.module = THIS_MODULE,
.name = "vhba",
.proc_name = "vhba",
.queuecommand = vhba_queuecommand,
.eh_abort_handler = vhba_abort,
.this_id = -1,
.max_sectors = VHBA_MAX_SECTORS_PER_IO,
.sg_tablesize = 256,
#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 19, 0)
.slave_alloc = vhba_slave_alloc,
#endif
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 0, 0)
.tag_alloc_policy = BLK_TAG_ALLOC_RR,
#endif
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 19, 0) && LINUX_VERSION_CODE < KERNEL_VERSION(4, 4, 0)
.use_blk_tags = 1,
#endif
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 0, 0)
.max_segment_size = VHBA_KBUF_SIZE,
#endif
};
ssize_t do_request (struct vhba_device *vdev, unsigned long metatag, struct scsi_cmnd *cmd, char __user *buf, size_t buf_len)
{
struct vhba_request vreq;
ssize_t ret;
scmd_dbg(cmd, "request %lu (%p), cdb 0x%x, bufflen %d, sg count %d\n",
metatag, cmd, cmd->cmnd[0], scsi_bufflen(cmd), scsi_sg_count(cmd));
ret = sizeof(vreq);
if (DATA_TO_DEVICE(cmd->sc_data_direction)) {
ret += scsi_bufflen(cmd);
}
if (ret > buf_len) {
scmd_dbg(cmd, "buffer too small (%zd < %zd) for a request\n", buf_len, ret);
return -EIO;
}
vreq.metatag = metatag;
vreq.lun = cmd->device->lun;
memcpy(vreq.cdb, cmd->cmnd, MAX_COMMAND_SIZE);
vreq.cdb_len = cmd->cmd_len;
vreq.data_len = scsi_bufflen(cmd);
if (copy_to_user(buf, &vreq, sizeof(vreq))) {
return -EFAULT;
}
if (DATA_TO_DEVICE(cmd->sc_data_direction) && vreq.data_len) {
buf += sizeof(vreq);
if (scsi_sg_count(cmd)) {
unsigned char *kaddr, *uaddr;
struct scatterlist *sglist = scsi_sglist(cmd);
struct scatterlist *sg;
int i;
uaddr = (unsigned char *) buf;
for_each_sg(sglist, sg, scsi_sg_count(cmd), i) {
size_t len = sg->length;
if (len > vdev->kbuf_size) {
scmd_dbg(cmd, "segment size (%zu) exceeds kbuf size (%zu)!", len, vdev->kbuf_size);
len = vdev->kbuf_size;
}
kaddr = kmap_atomic(sg_page(sg));
memcpy(vdev->kbuf, kaddr + sg->offset, len);
kunmap_atomic(kaddr);
if (copy_to_user(uaddr, vdev->kbuf, len)) {
return -EFAULT;
}
uaddr += len;
}
} else {
if (copy_to_user(buf, scsi_sglist(cmd), vreq.data_len)) {
return -EFAULT;
}
}
}
return ret;
}
ssize_t do_response (struct vhba_device *vdev, unsigned long metatag, struct scsi_cmnd *cmd, const char __user *buf, size_t buf_len, struct vhba_response *res)
{
ssize_t ret = 0;
scmd_dbg(cmd, "response %lu (%p), status %x, data len %d, sg count %d\n",
metatag, cmd, res->status, res->data_len, scsi_sg_count(cmd));
if (res->status) {
if (res->data_len > SCSI_SENSE_BUFFERSIZE) {
scmd_dbg(cmd, "truncate sense (%d < %d)", SCSI_SENSE_BUFFERSIZE, res->data_len);
res->data_len = SCSI_SENSE_BUFFERSIZE;
}
if (copy_from_user(cmd->sense_buffer, buf, res->data_len)) {
return -EFAULT;
}
cmd->result = res->status;
ret += res->data_len;
} else if (DATA_FROM_DEVICE(cmd->sc_data_direction) && scsi_bufflen(cmd)) {
size_t to_read;
if (res->data_len > scsi_bufflen(cmd)) {
scmd_dbg(cmd, "truncate data (%d < %d)\n", scsi_bufflen(cmd), res->data_len);
res->data_len = scsi_bufflen(cmd);
}
to_read = res->data_len;
if (scsi_sg_count(cmd)) {
unsigned char *kaddr, *uaddr;
struct scatterlist *sglist = scsi_sglist(cmd);
struct scatterlist *sg;
int i;
uaddr = (unsigned char *)buf;
for_each_sg(sglist, sg, scsi_sg_count(cmd), i) {
size_t len = (sg->length < to_read) ? sg->length : to_read;
if (len > vdev->kbuf_size) {
scmd_dbg(cmd, "segment size (%zu) exceeds kbuf size (%zu)!", len, vdev->kbuf_size);
len = vdev->kbuf_size;
}
if (copy_from_user(vdev->kbuf, uaddr, len)) {
return -EFAULT;
}
uaddr += len;
kaddr = kmap_atomic(sg_page(sg));
memcpy(kaddr + sg->offset, vdev->kbuf, len);
kunmap_atomic(kaddr);
to_read -= len;
if (to_read == 0) {
break;
}
}
} else {
if (copy_from_user(scsi_sglist(cmd), buf, res->data_len)) {
return -EFAULT;
}
to_read -= res->data_len;
}
scsi_set_resid(cmd, to_read);
ret += res->data_len - to_read;
}
return ret;
}
struct vhba_command *next_command (struct vhba_device *vdev)
{
struct vhba_command *vcmd;
list_for_each_entry(vcmd, &vdev->cmd_list, entry) {
if (vcmd->status == VHBA_REQ_PENDING) {
break;
}
}
if (&vcmd->entry == &vdev->cmd_list) {
vcmd = NULL;
}
return vcmd;
}
struct vhba_command *match_command (struct vhba_device *vdev, __u32 metatag)
{
struct vhba_command *vcmd;
list_for_each_entry(vcmd, &vdev->cmd_list, entry) {
if (vcmd->metatag == metatag) {
break;
}
}
if (&vcmd->entry == &vdev->cmd_list) {
vcmd = NULL;
}
return vcmd;
}
struct vhba_command *wait_command (struct vhba_device *vdev, unsigned long flags)
{
struct vhba_command *vcmd;
DEFINE_WAIT(wait);
while (!(vcmd = next_command(vdev))) {
if (signal_pending(current)) {
break;
}
prepare_to_wait(&vdev->cmd_wq, &wait, TASK_INTERRUPTIBLE);
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
schedule();
spin_lock_irqsave(&vdev->cmd_lock, flags);
}
finish_wait(&vdev->cmd_wq, &wait);
if (vcmd) {
vcmd->status = VHBA_REQ_READING;
}
return vcmd;
}
ssize_t vhba_ctl_read (struct file *file, char __user *buf, size_t buf_len, loff_t *offset)
{
struct vhba_device *vdev;
struct vhba_command *vcmd;
ssize_t ret;
unsigned long flags;
vdev = file->private_data;
/* Get next command */
if (file->f_flags & O_NONBLOCK) {
/* Non-blocking variant */
spin_lock_irqsave(&vdev->cmd_lock, flags);
vcmd = next_command(vdev);
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
if (!vcmd) {
return -EWOULDBLOCK;
}
} else {
/* Blocking variant */
spin_lock_irqsave(&vdev->cmd_lock, flags);
vcmd = wait_command(vdev, flags);
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
if (!vcmd) {
return -ERESTARTSYS;
}
}
ret = do_request(vdev, vcmd->metatag, vcmd->cmd, buf, buf_len);
spin_lock_irqsave(&vdev->cmd_lock, flags);
if (ret >= 0) {
vcmd->status = VHBA_REQ_SENT;
*offset += ret;
} else {
vcmd->status = VHBA_REQ_PENDING;
}
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
return ret;
}
ssize_t vhba_ctl_write (struct file *file, const char __user *buf, size_t buf_len, loff_t *offset)
{
struct vhba_device *vdev;
struct vhba_command *vcmd;
struct vhba_response res;
ssize_t ret;
unsigned long flags;
if (buf_len < sizeof(res)) {
return -EIO;
}
if (copy_from_user(&res, buf, sizeof(res))) {
return -EFAULT;
}
vdev = file->private_data;
spin_lock_irqsave(&vdev->cmd_lock, flags);
vcmd = match_command(vdev, res.metatag);
if (!vcmd || vcmd->status != VHBA_REQ_SENT) {
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
pr_debug("ctl dev #%u not expecting response\n", vdev->num);
return -EIO;
}
vcmd->status = VHBA_REQ_WRITING;
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
ret = do_response(vdev, vcmd->metatag, vcmd->cmd, buf + sizeof(res), buf_len - sizeof(res), &res);
spin_lock_irqsave(&vdev->cmd_lock, flags);
if (ret >= 0) {
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
scsi_done(vcmd->cmd);
#else
vcmd->cmd->scsi_done(vcmd->cmd);
#endif
ret += sizeof(res);
/* don't compete with vhba_device_dequeue */
if (!list_empty(&vcmd->entry)) {
list_del_init(&vcmd->entry);
vhba_free_command(vcmd);
}
} else {
vcmd->status = VHBA_REQ_SENT;
}
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
return ret;
}
long vhba_ctl_ioctl (struct file *file, unsigned int cmd, unsigned long arg)
{
struct vhba_device *vdev = file->private_data;
struct vhba_host *vhost = platform_get_drvdata(&vhba_platform_device);
switch (cmd) {
case 0xBEEF001: {
unsigned int ident[4]; /* host, channel, id, lun */
ident[0] = vhost->shost->host_no;
devnum_to_bus_and_id(vdev->num, &ident[1], &ident[2]);
ident[3] = 0; /* lun */
if (copy_to_user((void *) arg, ident, sizeof(ident))) {
return -EFAULT;
}
return 0;
}
case 0xBEEF002: {
unsigned int devnum = vdev->num;
if (copy_to_user((void *) arg, &devnum, sizeof(devnum))) {
return -EFAULT;
}
return 0;
}
}
return -ENOTTY;
}
#ifdef CONFIG_COMPAT
long vhba_ctl_compat_ioctl (struct file *file, unsigned int cmd, unsigned long arg)
{
unsigned long compat_arg = (unsigned long)compat_ptr(arg);
return vhba_ctl_ioctl(file, cmd, compat_arg);
}
#endif
unsigned int vhba_ctl_poll (struct file *file, poll_table *wait)
{
struct vhba_device *vdev = file->private_data;
unsigned int mask = 0;
unsigned long flags;
poll_wait(file, &vdev->cmd_wq, wait);
spin_lock_irqsave(&vdev->cmd_lock, flags);
if (next_command(vdev)) {
mask |= POLLIN | POLLRDNORM;
}
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
return mask;
}
int vhba_ctl_open (struct inode *inode, struct file *file)
{
struct vhba_device *vdev;
int retval;
pr_debug("ctl dev open\n");
/* check if vhba is probed */
if (!platform_get_drvdata(&vhba_platform_device)) {
return -ENODEV;
}
vdev = vhba_device_alloc();
if (!vdev) {
return -ENOMEM;
}
vdev->kbuf_size = VHBA_KBUF_SIZE;
vdev->kbuf = kzalloc(vdev->kbuf_size, GFP_KERNEL);
if (!vdev->kbuf) {
return -ENOMEM;
}
if (!(retval = vhba_add_device(vdev))) {
file->private_data = vdev;
}
vhba_device_put(vdev);
return retval;
}
int vhba_ctl_release (struct inode *inode, struct file *file)
{
struct vhba_device *vdev;
struct vhba_command *vcmd;
unsigned long flags;
vdev = file->private_data;
pr_debug("ctl dev release\n");
vhba_device_get(vdev);
vhba_remove_device(vdev);
spin_lock_irqsave(&vdev->cmd_lock, flags);
list_for_each_entry(vcmd, &vdev->cmd_list, entry) {
WARN_ON(vcmd->status == VHBA_REQ_READING || vcmd->status == VHBA_REQ_WRITING);
scmd_dbg(vcmd->cmd, "device released with command %lu (%p)\n", vcmd->metatag, vcmd->cmd);
vcmd->cmd->result = DID_NO_CONNECT << 16;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
scsi_done(vcmd->cmd);
#else
vcmd->cmd->scsi_done(vcmd->cmd);
#endif
vhba_free_command(vcmd);
}
INIT_LIST_HEAD(&vdev->cmd_list);
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
kfree(vdev->kbuf);
vdev->kbuf = NULL;
vhba_device_put(vdev);
return 0;
}
static struct file_operations vhba_ctl_fops = {
.owner = THIS_MODULE,
.open = vhba_ctl_open,
.release = vhba_ctl_release,
.read = vhba_ctl_read,
.write = vhba_ctl_write,
.poll = vhba_ctl_poll,
.unlocked_ioctl = vhba_ctl_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = vhba_ctl_compat_ioctl,
#endif
};
static struct miscdevice vhba_miscdev = {
.minor = MISC_DYNAMIC_MINOR,
.name = "vhba_ctl",
.fops = &vhba_ctl_fops,
};
int vhba_probe (struct platform_device *pdev)
{
struct Scsi_Host *shost;
struct vhba_host *vhost;
int i;
vhba_can_queue = clamp(vhba_can_queue, 1, 256);
shost = scsi_host_alloc(&vhba_template, sizeof(struct vhba_host));
if (!shost) {
return -ENOMEM;
}
shost->max_channel = VHBA_MAX_BUS-1;
shost->max_id = VHBA_MAX_ID;
/* we don't support lun > 0 */
shost->max_lun = 1;
shost->max_cmd_len = MAX_COMMAND_SIZE;
shost->can_queue = vhba_can_queue;
shost->cmd_per_lun = vhba_can_queue;
vhost = (struct vhba_host *)shost->hostdata;
memset(vhost, 0, sizeof(struct vhba_host));
vhost->shost = shost;
vhost->num_devices = 0;
spin_lock_init(&vhost->dev_lock);
spin_lock_init(&vhost->cmd_lock);
INIT_WORK(&vhost->scan_devices, vhba_scan_devices);
vhost->cmd_next = 0;
vhost->commands = kzalloc(vhba_can_queue * sizeof(struct vhba_command), GFP_KERNEL);
if (!vhost->commands) {
return -ENOMEM;
}
for (i = 0; i < vhba_can_queue; i++) {
vhost->commands[i].status = VHBA_REQ_FREE;
}
platform_set_drvdata(pdev, vhost);
#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 4, 0)
i = scsi_init_shared_tag_map(shost, vhba_can_queue);
if (i) return i;
#endif
if (scsi_add_host(shost, &pdev->dev)) {
scsi_host_put(shost);
return -ENOMEM;
}
return 0;
}
int vhba_remove (struct platform_device *pdev)
{
struct vhba_host *vhost;
struct Scsi_Host *shost;
vhost = platform_get_drvdata(pdev);
shost = vhost->shost;
scsi_remove_host(shost);
scsi_host_put(shost);
kfree(vhost->commands);
return 0;
}
void vhba_release (struct device * dev)
{
return;
}
static struct platform_device vhba_platform_device = {
.name = "vhba",
.id = -1,
.dev = {
.release = vhba_release,
},
};
static struct platform_driver vhba_platform_driver = {
.driver = {
.owner = THIS_MODULE,
.name = "vhba",
},
.probe = vhba_probe,
.remove = vhba_remove,
};
int __init vhba_init (void)
{
int ret;
ret = platform_device_register(&vhba_platform_device);
if (ret < 0) {
return ret;
}
ret = platform_driver_register(&vhba_platform_driver);
if (ret < 0) {
platform_device_unregister(&vhba_platform_device);
return ret;
}
ret = misc_register(&vhba_miscdev);
if (ret < 0) {
platform_driver_unregister(&vhba_platform_driver);
platform_device_unregister(&vhba_platform_device);
return ret;
}
return 0;
}
void __exit vhba_exit(void)
{
misc_deregister(&vhba_miscdev);
platform_driver_unregister(&vhba_platform_driver);
platform_device_unregister(&vhba_platform_device);
}
module_init(vhba_init);
module_exit(vhba_exit);