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linux-zen-desktop/drivers/target/target_core_user.c

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Initial commit
2023-08-30 17:31:07 +02:00
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2013 Shaohua Li <shli@kernel.org>
* Copyright (C) 2014 Red Hat, Inc.
* Copyright (C) 2015 Arrikto, Inc.
* Copyright (C) 2017 Chinamobile, Inc.
*/
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/parser.h>
#include <linux/vmalloc.h>
#include <linux/uio_driver.h>
#include <linux/xarray.h>
#include <linux/stringify.h>
#include <linux/bitops.h>
#include <linux/highmem.h>
#include <linux/configfs.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <linux/pagemap.h>
#include <net/genetlink.h>
#include <scsi/scsi_common.h>
#include <scsi/scsi_proto.h>
#include <target/target_core_base.h>
#include <target/target_core_fabric.h>
#include <target/target_core_backend.h>
#include <linux/target_core_user.h>
/**
* DOC: Userspace I/O
* Userspace I/O
* -------------
*
* Define a shared-memory interface for LIO to pass SCSI commands and
* data to userspace for processing. This is to allow backends that
* are too complex for in-kernel support to be possible.
*
* It uses the UIO framework to do a lot of the device-creation and
* introspection work for us.
*
* See the .h file for how the ring is laid out. Note that while the
* command ring is defined, the particulars of the data area are
* not. Offset values in the command entry point to other locations
* internal to the mmap-ed area. There is separate space outside the
* command ring for data buffers. This leaves maximum flexibility for
* moving buffer allocations, or even page flipping or other
* allocation techniques, without altering the command ring layout.
*
* SECURITY:
* The user process must be assumed to be malicious. There's no way to
* prevent it breaking the command ring protocol if it wants, but in
* order to prevent other issues we must only ever read *data* from
* the shared memory area, not offsets or sizes. This applies to
* command ring entries as well as the mailbox. Extra code needed for
* this may have a 'UAM' comment.
*/
#define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
/* For mailbox plus cmd ring, the size is fixed 8MB */
#define MB_CMDR_SIZE_DEF (8 * 1024 * 1024)
/* Offset of cmd ring is size of mailbox */
#define CMDR_OFF ((__u32)sizeof(struct tcmu_mailbox))
#define CMDR_SIZE_DEF (MB_CMDR_SIZE_DEF - CMDR_OFF)
/*
* For data area, the default block size is PAGE_SIZE and
* the default total size is 256K * PAGE_SIZE.
*/
#define DATA_PAGES_PER_BLK_DEF 1
#define DATA_AREA_PAGES_DEF (256 * 1024)
#define TCMU_MBS_TO_PAGES(_mbs) ((size_t)_mbs << (20 - PAGE_SHIFT))
#define TCMU_PAGES_TO_MBS(_pages) (_pages >> (20 - PAGE_SHIFT))
/*
* Default number of global data blocks(512K * PAGE_SIZE)
* when the unmap thread will be started.
*/
#define TCMU_GLOBAL_MAX_PAGES_DEF (512 * 1024)
static u8 tcmu_kern_cmd_reply_supported;
static u8 tcmu_netlink_blocked;
static struct device *tcmu_root_device;
struct tcmu_hba {
u32 host_id;
};
#define TCMU_CONFIG_LEN 256
static DEFINE_MUTEX(tcmu_nl_cmd_mutex);
static LIST_HEAD(tcmu_nl_cmd_list);
struct tcmu_dev;
struct tcmu_nl_cmd {
/* wake up thread waiting for reply */
struct completion complete;
struct list_head nl_list;
struct tcmu_dev *udev;
int cmd;
int status;
};
struct tcmu_dev {
struct list_head node;
struct kref kref;
struct se_device se_dev;
struct se_dev_plug se_plug;
char *name;
struct se_hba *hba;
#define TCMU_DEV_BIT_OPEN 0
#define TCMU_DEV_BIT_BROKEN 1
#define TCMU_DEV_BIT_BLOCKED 2
#define TCMU_DEV_BIT_TMR_NOTIFY 3
#define TCMU_DEV_BIT_PLUGGED 4
unsigned long flags;
struct uio_info uio_info;
struct inode *inode;
uint64_t dev_size;
struct tcmu_mailbox *mb_addr;
void *cmdr;
u32 cmdr_size;
u32 cmdr_last_cleaned;
/* Offset of data area from start of mb */
/* Must add data_off and mb_addr to get the address */
size_t data_off;
int data_area_mb;
uint32_t max_blocks;
size_t mmap_pages;
struct mutex cmdr_lock;
struct list_head qfull_queue;
struct list_head tmr_queue;
uint32_t dbi_max;
uint32_t dbi_thresh;
unsigned long *data_bitmap;
struct xarray data_pages;
uint32_t data_pages_per_blk;
uint32_t data_blk_size;
struct xarray commands;
struct timer_list cmd_timer;
unsigned int cmd_time_out;
struct list_head inflight_queue;
struct timer_list qfull_timer;
int qfull_time_out;
struct list_head timedout_entry;
struct tcmu_nl_cmd curr_nl_cmd;
char dev_config[TCMU_CONFIG_LEN];
int nl_reply_supported;
};
#define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
struct tcmu_cmd {
struct se_cmd *se_cmd;
struct tcmu_dev *tcmu_dev;
struct list_head queue_entry;
uint16_t cmd_id;
/* Can't use se_cmd when cleaning up expired cmds, because if
cmd has been completed then accessing se_cmd is off limits */
uint32_t dbi_cnt;
uint32_t dbi_bidi_cnt;
uint32_t dbi_cur;
uint32_t *dbi;
uint32_t data_len_bidi;
unsigned long deadline;
#define TCMU_CMD_BIT_EXPIRED 0
#define TCMU_CMD_BIT_KEEP_BUF 1
unsigned long flags;
};
struct tcmu_tmr {
struct list_head queue_entry;
uint8_t tmr_type;
uint32_t tmr_cmd_cnt;
int16_t tmr_cmd_ids[];
};
/*
* To avoid dead lock the mutex lock order should always be:
*
* mutex_lock(&root_udev_mutex);
* ...
* mutex_lock(&tcmu_dev->cmdr_lock);
* mutex_unlock(&tcmu_dev->cmdr_lock);
* ...
* mutex_unlock(&root_udev_mutex);
*/
static DEFINE_MUTEX(root_udev_mutex);
static LIST_HEAD(root_udev);
static DEFINE_SPINLOCK(timed_out_udevs_lock);
static LIST_HEAD(timed_out_udevs);
static struct kmem_cache *tcmu_cmd_cache;
static atomic_t global_page_count = ATOMIC_INIT(0);
static struct delayed_work tcmu_unmap_work;
static int tcmu_global_max_pages = TCMU_GLOBAL_MAX_PAGES_DEF;
static int tcmu_set_global_max_data_area(const char *str,
const struct kernel_param *kp)
{
int ret, max_area_mb;
ret = kstrtoint(str, 10, &max_area_mb);
if (ret)
return -EINVAL;
if (max_area_mb <= 0) {
pr_err("global_max_data_area must be larger than 0.\n");
return -EINVAL;
}
tcmu_global_max_pages = TCMU_MBS_TO_PAGES(max_area_mb);
if (atomic_read(&global_page_count) > tcmu_global_max_pages)
schedule_delayed_work(&tcmu_unmap_work, 0);
else
cancel_delayed_work_sync(&tcmu_unmap_work);
return 0;
}
static int tcmu_get_global_max_data_area(char *buffer,
const struct kernel_param *kp)
{
return sprintf(buffer, "%d\n", TCMU_PAGES_TO_MBS(tcmu_global_max_pages));
}
static const struct kernel_param_ops tcmu_global_max_data_area_op = {
.set = tcmu_set_global_max_data_area,
.get = tcmu_get_global_max_data_area,
};
module_param_cb(global_max_data_area_mb, &tcmu_global_max_data_area_op, NULL,
S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(global_max_data_area_mb,
"Max MBs allowed to be allocated to all the tcmu device's "
"data areas.");
static int tcmu_get_block_netlink(char *buffer,
const struct kernel_param *kp)
{
return sprintf(buffer, "%s\n", tcmu_netlink_blocked ?
"blocked" : "unblocked");
}
static int tcmu_set_block_netlink(const char *str,
const struct kernel_param *kp)
{
int ret;
u8 val;
ret = kstrtou8(str, 0, &val);
if (ret < 0)
return ret;
if (val > 1) {
pr_err("Invalid block netlink value %u\n", val);
return -EINVAL;
}
tcmu_netlink_blocked = val;
return 0;
}
static const struct kernel_param_ops tcmu_block_netlink_op = {
.set = tcmu_set_block_netlink,
.get = tcmu_get_block_netlink,
};
module_param_cb(block_netlink, &tcmu_block_netlink_op, NULL, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(block_netlink, "Block new netlink commands.");
static int tcmu_fail_netlink_cmd(struct tcmu_nl_cmd *nl_cmd)
{
struct tcmu_dev *udev = nl_cmd->udev;
if (!tcmu_netlink_blocked) {
pr_err("Could not reset device's netlink interface. Netlink is not blocked.\n");
return -EBUSY;
}
if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
pr_debug("Aborting nl cmd %d on %s\n", nl_cmd->cmd, udev->name);
nl_cmd->status = -EINTR;
list_del(&nl_cmd->nl_list);
complete(&nl_cmd->complete);
}
return 0;
}
static int tcmu_set_reset_netlink(const char *str,
const struct kernel_param *kp)
{
struct tcmu_nl_cmd *nl_cmd, *tmp_cmd;
int ret;
u8 val;
ret = kstrtou8(str, 0, &val);
if (ret < 0)
return ret;
if (val != 1) {
pr_err("Invalid reset netlink value %u\n", val);
return -EINVAL;
}
mutex_lock(&tcmu_nl_cmd_mutex);
list_for_each_entry_safe(nl_cmd, tmp_cmd, &tcmu_nl_cmd_list, nl_list) {
ret = tcmu_fail_netlink_cmd(nl_cmd);
if (ret)
break;
}
mutex_unlock(&tcmu_nl_cmd_mutex);
return ret;
}
static const struct kernel_param_ops tcmu_reset_netlink_op = {
.set = tcmu_set_reset_netlink,
};
module_param_cb(reset_netlink, &tcmu_reset_netlink_op, NULL, S_IWUSR);
MODULE_PARM_DESC(reset_netlink, "Reset netlink commands.");
/* multicast group */
enum tcmu_multicast_groups {
TCMU_MCGRP_CONFIG,
};
static const struct genl_multicast_group tcmu_mcgrps[] = {
[TCMU_MCGRP_CONFIG] = { .name = "config", },
};
static struct nla_policy tcmu_attr_policy[TCMU_ATTR_MAX+1] = {
[TCMU_ATTR_DEVICE] = { .type = NLA_STRING },
[TCMU_ATTR_MINOR] = { .type = NLA_U32 },
[TCMU_ATTR_CMD_STATUS] = { .type = NLA_S32 },
[TCMU_ATTR_DEVICE_ID] = { .type = NLA_U32 },
[TCMU_ATTR_SUPP_KERN_CMD_REPLY] = { .type = NLA_U8 },
};
static int tcmu_genl_cmd_done(struct genl_info *info, int completed_cmd)
{
struct tcmu_dev *udev = NULL;
struct tcmu_nl_cmd *nl_cmd;
int dev_id, rc, ret = 0;
if (!info->attrs[TCMU_ATTR_CMD_STATUS] ||
!info->attrs[TCMU_ATTR_DEVICE_ID]) {
printk(KERN_ERR "TCMU_ATTR_CMD_STATUS or TCMU_ATTR_DEVICE_ID not set, doing nothing\n");
return -EINVAL;
}
dev_id = nla_get_u32(info->attrs[TCMU_ATTR_DEVICE_ID]);
rc = nla_get_s32(info->attrs[TCMU_ATTR_CMD_STATUS]);
mutex_lock(&tcmu_nl_cmd_mutex);
list_for_each_entry(nl_cmd, &tcmu_nl_cmd_list, nl_list) {
if (nl_cmd->udev->se_dev.dev_index == dev_id) {
udev = nl_cmd->udev;
break;
}
}
if (!udev) {
pr_err("tcmu nl cmd %u/%d completion could not find device with dev id %u.\n",
completed_cmd, rc, dev_id);
ret = -ENODEV;
goto unlock;
}
list_del(&nl_cmd->nl_list);
pr_debug("%s genl cmd done got id %d curr %d done %d rc %d stat %d\n",
udev->name, dev_id, nl_cmd->cmd, completed_cmd, rc,
nl_cmd->status);
if (nl_cmd->cmd != completed_cmd) {
pr_err("Mismatched commands on %s (Expecting reply for %d. Current %d).\n",
udev->name, completed_cmd, nl_cmd->cmd);
ret = -EINVAL;
goto unlock;
}
nl_cmd->status = rc;
complete(&nl_cmd->complete);
unlock:
mutex_unlock(&tcmu_nl_cmd_mutex);
return ret;
}
static int tcmu_genl_rm_dev_done(struct sk_buff *skb, struct genl_info *info)
{
return tcmu_genl_cmd_done(info, TCMU_CMD_REMOVED_DEVICE);
}
static int tcmu_genl_add_dev_done(struct sk_buff *skb, struct genl_info *info)
{
return tcmu_genl_cmd_done(info, TCMU_CMD_ADDED_DEVICE);
}
static int tcmu_genl_reconfig_dev_done(struct sk_buff *skb,
struct genl_info *info)
{
return tcmu_genl_cmd_done(info, TCMU_CMD_RECONFIG_DEVICE);
}
static int tcmu_genl_set_features(struct sk_buff *skb, struct genl_info *info)
{
if (info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]) {
tcmu_kern_cmd_reply_supported =
nla_get_u8(info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]);
printk(KERN_INFO "tcmu daemon: command reply support %u.\n",
tcmu_kern_cmd_reply_supported);
}
return 0;
}
static const struct genl_small_ops tcmu_genl_ops[] = {
{
.cmd = TCMU_CMD_SET_FEATURES,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.flags = GENL_ADMIN_PERM,
.doit = tcmu_genl_set_features,
},
{
.cmd = TCMU_CMD_ADDED_DEVICE_DONE,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.flags = GENL_ADMIN_PERM,
.doit = tcmu_genl_add_dev_done,
},
{
.cmd = TCMU_CMD_REMOVED_DEVICE_DONE,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.flags = GENL_ADMIN_PERM,
.doit = tcmu_genl_rm_dev_done,
},
{
.cmd = TCMU_CMD_RECONFIG_DEVICE_DONE,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.flags = GENL_ADMIN_PERM,
.doit = tcmu_genl_reconfig_dev_done,
},
};
/* Our generic netlink family */
static struct genl_family tcmu_genl_family __ro_after_init = {
.module = THIS_MODULE,
.hdrsize = 0,
.name = "TCM-USER",
.version = 2,
.maxattr = TCMU_ATTR_MAX,
.policy = tcmu_attr_policy,
.mcgrps = tcmu_mcgrps,
.n_mcgrps = ARRAY_SIZE(tcmu_mcgrps),
.netnsok = true,
.small_ops = tcmu_genl_ops,
.n_small_ops = ARRAY_SIZE(tcmu_genl_ops),
.resv_start_op = TCMU_CMD_SET_FEATURES + 1,
};
#define tcmu_cmd_set_dbi_cur(cmd, index) ((cmd)->dbi_cur = (index))
#define tcmu_cmd_reset_dbi_cur(cmd) tcmu_cmd_set_dbi_cur(cmd, 0)
#define tcmu_cmd_set_dbi(cmd, index) ((cmd)->dbi[(cmd)->dbi_cur++] = (index))
#define tcmu_cmd_get_dbi(cmd) ((cmd)->dbi[(cmd)->dbi_cur++])
static void tcmu_cmd_free_data(struct tcmu_cmd *tcmu_cmd, uint32_t len)
{
struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
uint32_t i;
for (i = 0; i < len; i++)
clear_bit(tcmu_cmd->dbi[i], udev->data_bitmap);
}
static inline int tcmu_get_empty_block(struct tcmu_dev *udev,
struct tcmu_cmd *tcmu_cmd,
int prev_dbi, int length, int *iov_cnt)
{
XA_STATE(xas, &udev->data_pages, 0);
struct page *page;
int i, cnt, dbi, dpi;
int page_cnt = DIV_ROUND_UP(length, PAGE_SIZE);
dbi = find_first_zero_bit(udev->data_bitmap, udev->dbi_thresh);
if (dbi == udev->dbi_thresh)
return -1;
dpi = dbi * udev->data_pages_per_blk;
/* Count the number of already allocated pages */
xas_set(&xas, dpi);
rcu_read_lock();
for (cnt = 0; xas_next(&xas) && cnt < page_cnt;)
cnt++;
rcu_read_unlock();
for (i = cnt; i < page_cnt; i++) {
/* try to get new zeroed page from the mm */
page = alloc_page(GFP_NOIO | __GFP_ZERO);
if (!page)
break;
if (xa_store(&udev->data_pages, dpi + i, page, GFP_NOIO)) {
__free_page(page);
break;
}
}
if (atomic_add_return(i - cnt, &global_page_count) >
tcmu_global_max_pages)
schedule_delayed_work(&tcmu_unmap_work, 0);
if (i && dbi > udev->dbi_max)
udev->dbi_max = dbi;
set_bit(dbi, udev->data_bitmap);
tcmu_cmd_set_dbi(tcmu_cmd, dbi);
if (dbi != prev_dbi + 1)
*iov_cnt += 1;
return i == page_cnt ? dbi : -1;
}
static int tcmu_get_empty_blocks(struct tcmu_dev *udev,
struct tcmu_cmd *tcmu_cmd, int length)
{
/* start value of dbi + 1 must not be a valid dbi */
int dbi = -2;
int blk_data_len, iov_cnt = 0;
uint32_t blk_size = udev->data_blk_size;
for (; length > 0; length -= blk_size) {
blk_data_len = min_t(uint32_t, length, blk_size);
dbi = tcmu_get_empty_block(udev, tcmu_cmd, dbi, blk_data_len,
&iov_cnt);
if (dbi < 0)
return -1;
}
return iov_cnt;
}
static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd)
{
kfree(tcmu_cmd->dbi);
kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
}
static inline void tcmu_cmd_set_block_cnts(struct tcmu_cmd *cmd)
{
int i, len;
struct se_cmd *se_cmd = cmd->se_cmd;
uint32_t blk_size = cmd->tcmu_dev->data_blk_size;
cmd->dbi_cnt = DIV_ROUND_UP(se_cmd->data_length, blk_size);
if (se_cmd->se_cmd_flags & SCF_BIDI) {
BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
for (i = 0, len = 0; i < se_cmd->t_bidi_data_nents; i++)
len += se_cmd->t_bidi_data_sg[i].length;
cmd->dbi_bidi_cnt = DIV_ROUND_UP(len, blk_size);
cmd->dbi_cnt += cmd->dbi_bidi_cnt;
cmd->data_len_bidi = len;
}
}
static int new_block_to_iov(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
struct iovec **iov, int prev_dbi, int len)
{
/* Get the next dbi */
int dbi = tcmu_cmd_get_dbi(cmd);
/* Do not add more than udev->data_blk_size to iov */
len = min_t(int, len, udev->data_blk_size);
/*
* The following code will gather and map the blocks to the same iovec
* when the blocks are all next to each other.
*/
if (dbi != prev_dbi + 1) {
/* dbi is not next to previous dbi, so start new iov */
if (prev_dbi >= 0)
(*iov)++;
/* write offset relative to mb_addr */
(*iov)->iov_base = (void __user *)
(udev->data_off + dbi * udev->data_blk_size);
}
(*iov)->iov_len += len;
return dbi;
}
static void tcmu_setup_iovs(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
struct iovec **iov, int data_length)
{
/* start value of dbi + 1 must not be a valid dbi */
int dbi = -2;
/* We prepare the IOVs for DMA_FROM_DEVICE transfer direction */
for (; data_length > 0; data_length -= udev->data_blk_size)
dbi = new_block_to_iov(udev, cmd, iov, dbi, data_length);
}
static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
{
struct se_device *se_dev = se_cmd->se_dev;
struct tcmu_dev *udev = TCMU_DEV(se_dev);
struct tcmu_cmd *tcmu_cmd;
tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_NOIO);
if (!tcmu_cmd)
return NULL;
INIT_LIST_HEAD(&tcmu_cmd->queue_entry);
tcmu_cmd->se_cmd = se_cmd;
tcmu_cmd->tcmu_dev = udev;
tcmu_cmd_set_block_cnts(tcmu_cmd);
tcmu_cmd->dbi = kcalloc(tcmu_cmd->dbi_cnt, sizeof(uint32_t),
GFP_NOIO);
if (!tcmu_cmd->dbi) {
kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
return NULL;
}
return tcmu_cmd;
}
static inline void tcmu_flush_dcache_range(void *vaddr, size_t size)
{
unsigned long offset = offset_in_page(vaddr);
void *start = vaddr - offset;
size = round_up(size+offset, PAGE_SIZE);
while (size) {
flush_dcache_page(vmalloc_to_page(start));
start += PAGE_SIZE;
size -= PAGE_SIZE;
}
}
/*
* Some ring helper functions. We don't assume size is a power of 2 so
* we can't use circ_buf.h.
*/
static inline size_t spc_used(size_t head, size_t tail, size_t size)
{
int diff = head - tail;
if (diff >= 0)
return diff;
else
return size + diff;
}
static inline size_t spc_free(size_t head, size_t tail, size_t size)
{
/* Keep 1 byte unused or we can't tell full from empty */
return (size - spc_used(head, tail, size) - 1);
}
static inline size_t head_to_end(size_t head, size_t size)
{
return size - head;
}
#define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
#define TCMU_SG_TO_DATA_AREA 1
#define TCMU_DATA_AREA_TO_SG 2
static inline void tcmu_copy_data(struct tcmu_dev *udev,
struct tcmu_cmd *tcmu_cmd, uint32_t direction,
struct scatterlist *sg, unsigned int sg_nents,
struct iovec **iov, size_t data_len)
{
/* start value of dbi + 1 must not be a valid dbi */
int dbi = -2;
size_t page_remaining, cp_len;
int page_cnt, page_inx, dpi;
struct sg_mapping_iter sg_iter;
unsigned int sg_flags;
struct page *page;
void *data_page_start, *data_addr;
if (direction == TCMU_SG_TO_DATA_AREA)
sg_flags = SG_MITER_ATOMIC | SG_MITER_FROM_SG;
else
sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
sg_miter_start(&sg_iter, sg, sg_nents, sg_flags);
while (data_len) {
if (direction == TCMU_SG_TO_DATA_AREA)
dbi = new_block_to_iov(udev, tcmu_cmd, iov, dbi,
data_len);
else
dbi = tcmu_cmd_get_dbi(tcmu_cmd);
page_cnt = DIV_ROUND_UP(data_len, PAGE_SIZE);
if (page_cnt > udev->data_pages_per_blk)
page_cnt = udev->data_pages_per_blk;
dpi = dbi * udev->data_pages_per_blk;
for (page_inx = 0; page_inx < page_cnt && data_len;
page_inx++, dpi++) {
page = xa_load(&udev->data_pages, dpi);
if (direction == TCMU_DATA_AREA_TO_SG)
flush_dcache_page(page);
data_page_start = kmap_atomic(page);
page_remaining = PAGE_SIZE;
while (page_remaining && data_len) {
if (!sg_miter_next(&sg_iter)) {
/* set length to 0 to abort outer loop */
data_len = 0;
pr_debug("%s: aborting data copy due to exhausted sg_list\n",
__func__);
break;
}
cp_len = min3(sg_iter.length, page_remaining,
data_len);
data_addr = data_page_start +
PAGE_SIZE - page_remaining;
if (direction == TCMU_SG_TO_DATA_AREA)
memcpy(data_addr, sg_iter.addr, cp_len);
else
memcpy(sg_iter.addr, data_addr, cp_len);
data_len -= cp_len;
page_remaining -= cp_len;
sg_iter.consumed = cp_len;
}
sg_miter_stop(&sg_iter);
kunmap_atomic(data_page_start);
if (direction == TCMU_SG_TO_DATA_AREA)
flush_dcache_page(page);
}
}
}
static void scatter_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
struct iovec **iov)
{
struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
tcmu_copy_data(udev, tcmu_cmd, TCMU_SG_TO_DATA_AREA, se_cmd->t_data_sg,
se_cmd->t_data_nents, iov, se_cmd->data_length);
}
static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
bool bidi, uint32_t read_len)
{
struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
struct scatterlist *data_sg;
unsigned int data_nents;
if (!bidi) {
data_sg = se_cmd->t_data_sg;
data_nents = se_cmd->t_data_nents;
} else {
/*
* For bidi case, the first count blocks are for Data-Out
* buffer blocks, and before gathering the Data-In buffer
* the Data-Out buffer blocks should be skipped.
*/
tcmu_cmd_set_dbi_cur(tcmu_cmd,
tcmu_cmd->dbi_cnt - tcmu_cmd->dbi_bidi_cnt);
data_sg = se_cmd->t_bidi_data_sg;
data_nents = se_cmd->t_bidi_data_nents;
}
tcmu_copy_data(udev, tcmu_cmd, TCMU_DATA_AREA_TO_SG, data_sg,
data_nents, NULL, read_len);
}
static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh)
{
return thresh - bitmap_weight(bitmap, thresh);
}
/*
* We can't queue a command until we have space available on the cmd ring.
*
* Called with ring lock held.
*/
static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size)
{
struct tcmu_mailbox *mb = udev->mb_addr;
size_t space, cmd_needed;
u32 cmd_head;
tcmu_flush_dcache_range(mb, sizeof(*mb));
cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
/*
* If cmd end-of-ring space is too small then we need space for a NOP plus
* original cmd - cmds are internally contiguous.
*/
if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
cmd_needed = cmd_size;
else
cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
if (space < cmd_needed) {
pr_debug("no cmd space: %u %u %u\n", cmd_head,
udev->cmdr_last_cleaned, udev->cmdr_size);
return false;
}
return true;
}
/*
* We have to allocate data buffers before we can queue a command.
* Returns -1 on error (not enough space) or number of needed iovs on success
*
* Called with ring lock held.
*/
static int tcmu_alloc_data_space(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
int *iov_bidi_cnt)
{
int space, iov_cnt = 0, ret = 0;
if (!cmd->dbi_cnt)
goto wr_iov_cnts;
/* try to check and get the data blocks as needed */
space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh);
if (space < cmd->dbi_cnt) {
unsigned long blocks_left =
(udev->max_blocks - udev->dbi_thresh) + space;
if (blocks_left < cmd->dbi_cnt) {
pr_debug("no data space: only %lu available, but ask for %u\n",
blocks_left * udev->data_blk_size,
cmd->dbi_cnt * udev->data_blk_size);
return -1;
}
udev->dbi_thresh += cmd->dbi_cnt;
if (udev->dbi_thresh > udev->max_blocks)
udev->dbi_thresh = udev->max_blocks;
}
iov_cnt = tcmu_get_empty_blocks(udev, cmd, cmd->se_cmd->data_length);
if (iov_cnt < 0)
return -1;
if (cmd->dbi_bidi_cnt) {
ret = tcmu_get_empty_blocks(udev, cmd, cmd->data_len_bidi);
if (ret < 0)
return -1;
}
wr_iov_cnts:
*iov_bidi_cnt = ret;
return iov_cnt + ret;
}
static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt)
{
return max(offsetof(struct tcmu_cmd_entry, req.iov[iov_cnt]),
sizeof(struct tcmu_cmd_entry));
}
static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd,
size_t base_command_size)
{
struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
size_t command_size;
command_size = base_command_size +
round_up(scsi_command_size(se_cmd->t_task_cdb),
TCMU_OP_ALIGN_SIZE);
WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
return command_size;
}
static void tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo,
struct timer_list *timer)
{
if (!tmo)
return;
tcmu_cmd->deadline = round_jiffies_up(jiffies + msecs_to_jiffies(tmo));
if (!timer_pending(timer))
mod_timer(timer, tcmu_cmd->deadline);
pr_debug("Timeout set up for cmd %p, dev = %s, tmo = %lu\n", tcmu_cmd,
tcmu_cmd->tcmu_dev->name, tmo / MSEC_PER_SEC);
}
static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd)
{
struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
unsigned int tmo;
/*
* For backwards compat if qfull_time_out is not set use
* cmd_time_out and if that's not set use the default time out.
*/
if (!udev->qfull_time_out)
return -ETIMEDOUT;
else if (udev->qfull_time_out > 0)
tmo = udev->qfull_time_out;
else if (udev->cmd_time_out)
tmo = udev->cmd_time_out;
else
tmo = TCMU_TIME_OUT;
tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer);
list_add_tail(&tcmu_cmd->queue_entry, &udev->qfull_queue);
pr_debug("adding cmd %p on dev %s to ring space wait queue\n",
tcmu_cmd, udev->name);
return 0;
}
static uint32_t ring_insert_padding(struct tcmu_dev *udev, size_t cmd_size)
{
struct tcmu_cmd_entry_hdr *hdr;
struct tcmu_mailbox *mb = udev->mb_addr;
uint32_t cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
/* Insert a PAD if end-of-ring space is too small */
if (head_to_end(cmd_head, udev->cmdr_size) < cmd_size) {
size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
hdr = udev->cmdr + cmd_head;
tcmu_hdr_set_op(&hdr->len_op, TCMU_OP_PAD);
tcmu_hdr_set_len(&hdr->len_op, pad_size);
hdr->cmd_id = 0; /* not used for PAD */
hdr->kflags = 0;
hdr->uflags = 0;
tcmu_flush_dcache_range(hdr, sizeof(*hdr));
UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
tcmu_flush_dcache_range(mb, sizeof(*mb));
cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
WARN_ON(cmd_head != 0);
}
return cmd_head;
}
static void tcmu_unplug_device(struct se_dev_plug *se_plug)
{
struct se_device *se_dev = se_plug->se_dev;
struct tcmu_dev *udev = TCMU_DEV(se_dev);
clear_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags);
uio_event_notify(&udev->uio_info);
}
static struct se_dev_plug *tcmu_plug_device(struct se_device *se_dev)
{
struct tcmu_dev *udev = TCMU_DEV(se_dev);
if (!test_and_set_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags))
return &udev->se_plug;
return NULL;
}
/**
* queue_cmd_ring - queue cmd to ring or internally
* @tcmu_cmd: cmd to queue
* @scsi_err: TCM error code if failure (-1) returned.
*
* Returns:
* -1 we cannot queue internally or to the ring.
* 0 success
* 1 internally queued to wait for ring memory to free.
*/
static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
{
struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
size_t base_command_size, command_size;
struct tcmu_mailbox *mb = udev->mb_addr;
struct tcmu_cmd_entry *entry;
struct iovec *iov;
int iov_cnt, iov_bidi_cnt;
uint32_t cmd_id, cmd_head;
uint64_t cdb_off;
uint32_t blk_size = udev->data_blk_size;
/* size of data buffer needed */
size_t data_length = (size_t)tcmu_cmd->dbi_cnt * blk_size;
*scsi_err = TCM_NO_SENSE;
if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) {
*scsi_err = TCM_LUN_BUSY;
return -1;
}
if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
*scsi_err = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
return -1;
}
if (!list_empty(&udev->qfull_queue))
goto queue;
if (data_length > (size_t)udev->max_blocks * blk_size) {
pr_warn("TCMU: Request of size %zu is too big for %zu data area\n",
data_length, (size_t)udev->max_blocks * blk_size);
*scsi_err = TCM_INVALID_CDB_FIELD;
return -1;
}
iov_cnt = tcmu_alloc_data_space(udev, tcmu_cmd, &iov_bidi_cnt);
if (iov_cnt < 0)
goto free_and_queue;
/*
* Must be a certain minimum size for response sense info, but
* also may be larger if the iov array is large.
*/
base_command_size = tcmu_cmd_get_base_cmd_size(iov_cnt);
command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
if (command_size > (udev->cmdr_size / 2)) {
pr_warn("TCMU: Request of size %zu is too big for %u cmd ring\n",
command_size, udev->cmdr_size);
tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
*scsi_err = TCM_INVALID_CDB_FIELD;
return -1;
}
if (!is_ring_space_avail(udev, command_size))
/*
* Don't leave commands partially setup because the unmap
* thread might need the blocks to make forward progress.
*/
goto free_and_queue;
if (xa_alloc(&udev->commands, &cmd_id, tcmu_cmd, XA_LIMIT(1, 0xffff),
GFP_NOWAIT) < 0) {
pr_err("tcmu: Could not allocate cmd id.\n");
tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt);
*scsi_err = TCM_OUT_OF_RESOURCES;
return -1;
}
tcmu_cmd->cmd_id = cmd_id;
pr_debug("allocated cmd id %u for cmd %p dev %s\n", tcmu_cmd->cmd_id,
tcmu_cmd, udev->name);
cmd_head = ring_insert_padding(udev, command_size);
entry = udev->cmdr + cmd_head;
memset(entry, 0, command_size);
tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
/* prepare iov list and copy data to data area if necessary */
tcmu_cmd_reset_dbi_cur(tcmu_cmd);
iov = &entry->req.iov[0];
if (se_cmd->data_direction == DMA_TO_DEVICE ||
se_cmd->se_cmd_flags & SCF_BIDI)
scatter_data_area(udev, tcmu_cmd, &iov);
else
tcmu_setup_iovs(udev, tcmu_cmd, &iov, se_cmd->data_length);
entry->req.iov_cnt = iov_cnt - iov_bidi_cnt;
/* Handle BIDI commands */
if (se_cmd->se_cmd_flags & SCF_BIDI) {
iov++;
tcmu_setup_iovs(udev, tcmu_cmd, &iov, tcmu_cmd->data_len_bidi);
entry->req.iov_bidi_cnt = iov_bidi_cnt;
}
tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out, &udev->cmd_timer);
entry->hdr.cmd_id = tcmu_cmd->cmd_id;
tcmu_hdr_set_len(&entry->hdr.len_op, command_size);
/* All offsets relative to mb_addr, not start of entry! */
cdb_off = CMDR_OFF + cmd_head + base_command_size;
memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
entry->req.cdb_off = cdb_off;
tcmu_flush_dcache_range(entry, command_size);
UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
tcmu_flush_dcache_range(mb, sizeof(*mb));
list_add_tail(&tcmu_cmd->queue_entry, &udev->inflight_queue);
if (!test_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags))
uio_event_notify(&udev->uio_info);
return 0;
free_and_queue:
tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
tcmu_cmd_reset_dbi_cur(tcmu_cmd);
queue:
if (add_to_qfull_queue(tcmu_cmd)) {
*scsi_err = TCM_OUT_OF_RESOURCES;
return -1;
}
return 1;
}
/**
* queue_tmr_ring - queue tmr info to ring or internally
* @udev: related tcmu_dev
* @tmr: tcmu_tmr containing tmr info to queue
*
* Returns:
* 0 success
* 1 internally queued to wait for ring memory to free.
*/
static int
queue_tmr_ring(struct tcmu_dev *udev, struct tcmu_tmr *tmr)
{
struct tcmu_tmr_entry *entry;
int cmd_size;
int id_list_sz;
struct tcmu_mailbox *mb = udev->mb_addr;
uint32_t cmd_head;
if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags))
goto out_free;
id_list_sz = sizeof(tmr->tmr_cmd_ids[0]) * tmr->tmr_cmd_cnt;
cmd_size = round_up(sizeof(*entry) + id_list_sz, TCMU_OP_ALIGN_SIZE);
if (!list_empty(&udev->tmr_queue) ||
!is_ring_space_avail(udev, cmd_size)) {
list_add_tail(&tmr->queue_entry, &udev->tmr_queue);
pr_debug("adding tmr %p on dev %s to TMR ring space wait queue\n",
tmr, udev->name);
return 1;
}
cmd_head = ring_insert_padding(udev, cmd_size);
entry = udev->cmdr + cmd_head;
memset(entry, 0, cmd_size);
tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_TMR);
tcmu_hdr_set_len(&entry->hdr.len_op, cmd_size);
entry->tmr_type = tmr->tmr_type;
entry->cmd_cnt = tmr->tmr_cmd_cnt;
memcpy(&entry->cmd_ids[0], &tmr->tmr_cmd_ids[0], id_list_sz);
tcmu_flush_dcache_range(entry, cmd_size);
UPDATE_HEAD(mb->cmd_head, cmd_size, udev->cmdr_size);
tcmu_flush_dcache_range(mb, sizeof(*mb));
uio_event_notify(&udev->uio_info);
out_free:
kfree(tmr);
return 0;
}
static sense_reason_t
tcmu_queue_cmd(struct se_cmd *se_cmd)
{
struct se_device *se_dev = se_cmd->se_dev;
struct tcmu_dev *udev = TCMU_DEV(se_dev);
struct tcmu_cmd *tcmu_cmd;
sense_reason_t scsi_ret = TCM_CHECK_CONDITION_ABORT_CMD;
int ret = -1;
tcmu_cmd = tcmu_alloc_cmd(se_cmd);
if (!tcmu_cmd)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
mutex_lock(&udev->cmdr_lock);
if (!(se_cmd->transport_state & CMD_T_ABORTED))
ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
if (ret < 0)
tcmu_free_cmd(tcmu_cmd);
else
se_cmd->priv = tcmu_cmd;
mutex_unlock(&udev->cmdr_lock);
return scsi_ret;
}
static void tcmu_set_next_deadline(struct list_head *queue,
struct timer_list *timer)
{
struct tcmu_cmd *cmd;
if (!list_empty(queue)) {
cmd = list_first_entry(queue, struct tcmu_cmd, queue_entry);
mod_timer(timer, cmd->deadline);
} else
del_timer(timer);
}
static int
tcmu_tmr_type(enum tcm_tmreq_table tmf)
{
switch (tmf) {
case TMR_ABORT_TASK: return TCMU_TMR_ABORT_TASK;
case TMR_ABORT_TASK_SET: return TCMU_TMR_ABORT_TASK_SET;
case TMR_CLEAR_ACA: return TCMU_TMR_CLEAR_ACA;
case TMR_CLEAR_TASK_SET: return TCMU_TMR_CLEAR_TASK_SET;
case TMR_LUN_RESET: return TCMU_TMR_LUN_RESET;
case TMR_TARGET_WARM_RESET: return TCMU_TMR_TARGET_WARM_RESET;
case TMR_TARGET_COLD_RESET: return TCMU_TMR_TARGET_COLD_RESET;
case TMR_LUN_RESET_PRO: return TCMU_TMR_LUN_RESET_PRO;
default: return TCMU_TMR_UNKNOWN;
}
}
static void
tcmu_tmr_notify(struct se_device *se_dev, enum tcm_tmreq_table tmf,
struct list_head *cmd_list)
{
int i = 0, cmd_cnt = 0;
bool unqueued = false;
struct tcmu_cmd *cmd;
struct se_cmd *se_cmd;
struct tcmu_tmr *tmr;
struct tcmu_dev *udev = TCMU_DEV(se_dev);
mutex_lock(&udev->cmdr_lock);
/* First we check for aborted commands in qfull_queue */
list_for_each_entry(se_cmd, cmd_list, state_list) {
i++;
if (!se_cmd->priv)
continue;
cmd = se_cmd->priv;
/* Commands on qfull queue have no id yet */
if (cmd->cmd_id) {
cmd_cnt++;
continue;
}
pr_debug("Removing aborted command %p from queue on dev %s.\n",
cmd, udev->name);
list_del_init(&cmd->queue_entry);
tcmu_free_cmd(cmd);
se_cmd->priv = NULL;
target_complete_cmd(se_cmd, SAM_STAT_TASK_ABORTED);
unqueued = true;
}
if (unqueued)
tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
if (!test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags))
goto unlock;
pr_debug("TMR event %d on dev %s, aborted cmds %d, afflicted cmd_ids %d\n",
tcmu_tmr_type(tmf), udev->name, i, cmd_cnt);
tmr = kmalloc(struct_size(tmr, tmr_cmd_ids, cmd_cnt), GFP_NOIO);
if (!tmr)
goto unlock;
tmr->tmr_type = tcmu_tmr_type(tmf);
tmr->tmr_cmd_cnt = cmd_cnt;
if (cmd_cnt != 0) {
cmd_cnt = 0;
list_for_each_entry(se_cmd, cmd_list, state_list) {
if (!se_cmd->priv)
continue;
cmd = se_cmd->priv;
if (cmd->cmd_id)
tmr->tmr_cmd_ids[cmd_cnt++] = cmd->cmd_id;
}
}
queue_tmr_ring(udev, tmr);
unlock:
mutex_unlock(&udev->cmdr_lock);
}
static bool tcmu_handle_completion(struct tcmu_cmd *cmd,
struct tcmu_cmd_entry *entry, bool keep_buf)
{
struct se_cmd *se_cmd = cmd->se_cmd;
struct tcmu_dev *udev = cmd->tcmu_dev;
bool read_len_valid = false;
bool ret = true;
uint32_t read_len;
/*
* cmd has been completed already from timeout, just reclaim
* data area space and free cmd
*/
if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
WARN_ON_ONCE(se_cmd);
goto out;
}
if (test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
pr_err("cmd_id %u already completed with KEEP_BUF, ring is broken\n",
entry->hdr.cmd_id);
set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
ret = false;
goto out;
}
list_del_init(&cmd->queue_entry);
tcmu_cmd_reset_dbi_cur(cmd);
if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) {
pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
cmd->se_cmd);
entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION;
goto done;
}
read_len = se_cmd->data_length;
if (se_cmd->data_direction == DMA_FROM_DEVICE &&
(entry->hdr.uflags & TCMU_UFLAG_READ_LEN) && entry->rsp.read_len) {
read_len_valid = true;
if (entry->rsp.read_len < read_len)
read_len = entry->rsp.read_len;
}
if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
transport_copy_sense_to_cmd(se_cmd, entry->rsp.sense_buffer);
if (!read_len_valid )
goto done;
else
se_cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
}
if (se_cmd->se_cmd_flags & SCF_BIDI) {
/* Get Data-In buffer before clean up */
gather_data_area(udev, cmd, true, read_len);
} else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
gather_data_area(udev, cmd, false, read_len);
} else if (se_cmd->data_direction == DMA_TO_DEVICE) {
/* TODO: */
} else if (se_cmd->data_direction != DMA_NONE) {
pr_warn("TCMU: data direction was %d!\n",
se_cmd->data_direction);
}
done:
se_cmd->priv = NULL;
if (read_len_valid) {
pr_debug("read_len = %d\n", read_len);
target_complete_cmd_with_length(cmd->se_cmd,
entry->rsp.scsi_status, read_len);
} else
target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
out:
if (!keep_buf) {
tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
tcmu_free_cmd(cmd);
} else {
/*
* Keep this command after completion, since userspace still
* needs the data buffer. Mark it with TCMU_CMD_BIT_KEEP_BUF
* and reset potential TCMU_CMD_BIT_EXPIRED, so we don't accept
* a second completion later.
* Userspace can free the buffer later by writing the cmd_id
* to new action attribute free_kept_buf.
*/
clear_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
set_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags);
}
return ret;
}
static int tcmu_run_tmr_queue(struct tcmu_dev *udev)
{
struct tcmu_tmr *tmr, *tmp;
LIST_HEAD(tmrs);
if (list_empty(&udev->tmr_queue))
return 1;
pr_debug("running %s's tmr queue\n", udev->name);
list_splice_init(&udev->tmr_queue, &tmrs);
list_for_each_entry_safe(tmr, tmp, &tmrs, queue_entry) {
list_del_init(&tmr->queue_entry);
pr_debug("removing tmr %p on dev %s from queue\n",
tmr, udev->name);
if (queue_tmr_ring(udev, tmr)) {
pr_debug("ran out of space during tmr queue run\n");
/*
* tmr was requeued, so just put all tmrs back in
* the queue
*/
list_splice_tail(&tmrs, &udev->tmr_queue);
return 0;
}
}
return 1;
}
static bool tcmu_handle_completions(struct tcmu_dev *udev)
{
struct tcmu_mailbox *mb;
struct tcmu_cmd *cmd;
bool free_space = false;
if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
pr_err("ring broken, not handling completions\n");
return false;
}
mb = udev->mb_addr;
tcmu_flush_dcache_range(mb, sizeof(*mb));
while (udev->cmdr_last_cleaned != READ_ONCE(mb->cmd_tail)) {
struct tcmu_cmd_entry *entry = udev->cmdr + udev->cmdr_last_cleaned;
bool keep_buf;
/*
* Flush max. up to end of cmd ring since current entry might
* be a padding that is shorter than sizeof(*entry)
*/
size_t ring_left = head_to_end(udev->cmdr_last_cleaned,
udev->cmdr_size);
tcmu_flush_dcache_range(entry, ring_left < sizeof(*entry) ?
ring_left : sizeof(*entry));
free_space = true;
if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD ||
tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_TMR) {
UPDATE_HEAD(udev->cmdr_last_cleaned,
tcmu_hdr_get_len(entry->hdr.len_op),
udev->cmdr_size);
continue;
}
WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD);
keep_buf = !!(entry->hdr.uflags & TCMU_UFLAG_KEEP_BUF);
if (keep_buf)
cmd = xa_load(&udev->commands, entry->hdr.cmd_id);
else
cmd = xa_erase(&udev->commands, entry->hdr.cmd_id);
if (!cmd) {
pr_err("cmd_id %u not found, ring is broken\n",
entry->hdr.cmd_id);
set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
return false;
}
if (!tcmu_handle_completion(cmd, entry, keep_buf))
break;
UPDATE_HEAD(udev->cmdr_last_cleaned,
tcmu_hdr_get_len(entry->hdr.len_op),
udev->cmdr_size);
}
if (free_space)
free_space = tcmu_run_tmr_queue(udev);
if (atomic_read(&global_page_count) > tcmu_global_max_pages &&
xa_empty(&udev->commands) && list_empty(&udev->qfull_queue)) {
/*
* Allocated blocks exceeded global block limit, currently no
* more pending or waiting commands so try to reclaim blocks.
*/
schedule_delayed_work(&tcmu_unmap_work, 0);
}
if (udev->cmd_time_out)
tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer);
return free_space;
}
static void tcmu_check_expired_ring_cmd(struct tcmu_cmd *cmd)
{
struct se_cmd *se_cmd;
if (!time_after_eq(jiffies, cmd->deadline))
return;
set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
list_del_init(&cmd->queue_entry);
se_cmd = cmd->se_cmd;
se_cmd->priv = NULL;
cmd->se_cmd = NULL;
pr_debug("Timing out inflight cmd %u on dev %s.\n",
cmd->cmd_id, cmd->tcmu_dev->name);
target_complete_cmd(se_cmd, SAM_STAT_CHECK_CONDITION);
}
static void tcmu_check_expired_queue_cmd(struct tcmu_cmd *cmd)
{
struct se_cmd *se_cmd;
if (!time_after_eq(jiffies, cmd->deadline))
return;
pr_debug("Timing out queued cmd %p on dev %s.\n",
cmd, cmd->tcmu_dev->name);
list_del_init(&cmd->queue_entry);
se_cmd = cmd->se_cmd;
tcmu_free_cmd(cmd);
se_cmd->priv = NULL;
target_complete_cmd(se_cmd, SAM_STAT_TASK_SET_FULL);
}
static void tcmu_device_timedout(struct tcmu_dev *udev)
{
spin_lock(&timed_out_udevs_lock);
if (list_empty(&udev->timedout_entry))
list_add_tail(&udev->timedout_entry, &timed_out_udevs);
spin_unlock(&timed_out_udevs_lock);
schedule_delayed_work(&tcmu_unmap_work, 0);
}
static void tcmu_cmd_timedout(struct timer_list *t)
{
struct tcmu_dev *udev = from_timer(udev, t, cmd_timer);
pr_debug("%s cmd timeout has expired\n", udev->name);
tcmu_device_timedout(udev);
}
static void tcmu_qfull_timedout(struct timer_list *t)
{
struct tcmu_dev *udev = from_timer(udev, t, qfull_timer);
pr_debug("%s qfull timeout has expired\n", udev->name);
tcmu_device_timedout(udev);
}
static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
{
struct tcmu_hba *tcmu_hba;
tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL);
if (!tcmu_hba)
return -ENOMEM;
tcmu_hba->host_id = host_id;
hba->hba_ptr = tcmu_hba;
return 0;
}
static void tcmu_detach_hba(struct se_hba *hba)
{
kfree(hba->hba_ptr);
hba->hba_ptr = NULL;
}
static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
{
struct tcmu_dev *udev;
udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL);
if (!udev)
return NULL;
kref_init(&udev->kref);
udev->name = kstrdup(name, GFP_KERNEL);
if (!udev->name) {
kfree(udev);
return NULL;
}
udev->hba = hba;
udev->cmd_time_out = TCMU_TIME_OUT;
udev->qfull_time_out = -1;
udev->data_pages_per_blk = DATA_PAGES_PER_BLK_DEF;
udev->max_blocks = DATA_AREA_PAGES_DEF / udev->data_pages_per_blk;
udev->cmdr_size = CMDR_SIZE_DEF;
udev->data_area_mb = TCMU_PAGES_TO_MBS(DATA_AREA_PAGES_DEF);
mutex_init(&udev->cmdr_lock);
INIT_LIST_HEAD(&udev->node);
INIT_LIST_HEAD(&udev->timedout_entry);
INIT_LIST_HEAD(&udev->qfull_queue);
INIT_LIST_HEAD(&udev->tmr_queue);
INIT_LIST_HEAD(&udev->inflight_queue);
xa_init_flags(&udev->commands, XA_FLAGS_ALLOC1);
timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0);
timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0);
xa_init(&udev->data_pages);
return &udev->se_dev;
}
static void tcmu_dev_call_rcu(struct rcu_head *p)
{
struct se_device *dev = container_of(p, struct se_device, rcu_head);
struct tcmu_dev *udev = TCMU_DEV(dev);
kfree(udev->uio_info.name);
kfree(udev->name);
kfree(udev);
}
static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd)
{
if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) ||
test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
kmem_cache_free(tcmu_cmd_cache, cmd);
return 0;
}
return -EINVAL;
}
static u32 tcmu_blocks_release(struct tcmu_dev *udev, unsigned long first,
unsigned long last)
{
struct page *page;
unsigned long dpi;
u32 pages_freed = 0;
first = first * udev->data_pages_per_blk;
last = (last + 1) * udev->data_pages_per_blk - 1;
xa_for_each_range(&udev->data_pages, dpi, page, first, last) {
xa_erase(&udev->data_pages, dpi);
/*
* While reaching here there may be page faults occurring on
* the to-be-released pages. A race condition may occur if
* unmap_mapping_range() is called before page faults on these
* pages have completed; a valid but stale map is created.
*
* If another command subsequently runs and needs to extend
* dbi_thresh, it may reuse the slot corresponding to the
* previous page in data_bitmap. Though we will allocate a new
* page for the slot in data_area, no page fault will happen
* because we have a valid map. Therefore the command's data
* will be lost.
*
* We lock and unlock pages that are to be released to ensure
* all page faults have completed. This way
* unmap_mapping_range() can ensure stale maps are cleanly
* removed.
*/
lock_page(page);
unlock_page(page);
__free_page(page);
pages_freed++;
}
atomic_sub(pages_freed, &global_page_count);
return pages_freed;
}
static void tcmu_remove_all_queued_tmr(struct tcmu_dev *udev)
{
struct tcmu_tmr *tmr, *tmp;
list_for_each_entry_safe(tmr, tmp, &udev->tmr_queue, queue_entry) {
list_del_init(&tmr->queue_entry);
kfree(tmr);
}
}
static void tcmu_dev_kref_release(struct kref *kref)
{
struct tcmu_dev *udev = container_of(kref, struct tcmu_dev, kref);
struct se_device *dev = &udev->se_dev;
struct tcmu_cmd *cmd;
bool all_expired = true;
unsigned long i;
vfree(udev->mb_addr);
udev->mb_addr = NULL;
spin_lock_bh(&timed_out_udevs_lock);
if (!list_empty(&udev->timedout_entry))
list_del(&udev->timedout_entry);
spin_unlock_bh(&timed_out_udevs_lock);
/* Upper layer should drain all requests before calling this */
mutex_lock(&udev->cmdr_lock);
xa_for_each(&udev->commands, i, cmd) {
if (tcmu_check_and_free_pending_cmd(cmd) != 0)
all_expired = false;
}
/* There can be left over TMR cmds. Remove them. */
tcmu_remove_all_queued_tmr(udev);
if (!list_empty(&udev->qfull_queue))
all_expired = false;
xa_destroy(&udev->commands);
WARN_ON(!all_expired);
tcmu_blocks_release(udev, 0, udev->dbi_max);
bitmap_free(udev->data_bitmap);
mutex_unlock(&udev->cmdr_lock);
pr_debug("dev_kref_release\n");
call_rcu(&dev->rcu_head, tcmu_dev_call_rcu);
}
static void run_qfull_queue(struct tcmu_dev *udev, bool fail)
{
struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
LIST_HEAD(cmds);
sense_reason_t scsi_ret;
int ret;
if (list_empty(&udev->qfull_queue))
return;
pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail);
list_splice_init(&udev->qfull_queue, &cmds);
list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) {
list_del_init(&tcmu_cmd->queue_entry);
pr_debug("removing cmd %p on dev %s from queue\n",
tcmu_cmd, udev->name);
if (fail) {
/*
* We were not able to even start the command, so
* fail with busy to allow a retry in case runner
* was only temporarily down. If the device is being
* removed then LIO core will do the right thing and
* fail the retry.
*/
tcmu_cmd->se_cmd->priv = NULL;
target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_BUSY);
tcmu_free_cmd(tcmu_cmd);
continue;
}
ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
if (ret < 0) {
pr_debug("cmd %p on dev %s failed with %u\n",
tcmu_cmd, udev->name, scsi_ret);
/*
* Ignore scsi_ret for now. target_complete_cmd
* drops it.
*/
tcmu_cmd->se_cmd->priv = NULL;
target_complete_cmd(tcmu_cmd->se_cmd,
SAM_STAT_CHECK_CONDITION);
tcmu_free_cmd(tcmu_cmd);
} else if (ret > 0) {
pr_debug("ran out of space during cmdr queue run\n");
/*
* cmd was requeued, so just put all cmds back in
* the queue
*/
list_splice_tail(&cmds, &udev->qfull_queue);
break;
}
}
tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
}
static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
{
struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
mutex_lock(&udev->cmdr_lock);
if (tcmu_handle_completions(udev))
run_qfull_queue(udev, false);
mutex_unlock(&udev->cmdr_lock);
return 0;
}
/*
* mmap code from uio.c. Copied here because we want to hook mmap()
* and this stuff must come along.
*/
static int tcmu_find_mem_index(struct vm_area_struct *vma)
{
struct tcmu_dev *udev = vma->vm_private_data;
struct uio_info *info = &udev->uio_info;
if (vma->vm_pgoff < MAX_UIO_MAPS) {
if (info->mem[vma->vm_pgoff].size == 0)
return -1;
return (int)vma->vm_pgoff;
}
return -1;
}
static struct page *tcmu_try_get_data_page(struct tcmu_dev *udev, uint32_t dpi)
{
struct page *page;
mutex_lock(&udev->cmdr_lock);
page = xa_load(&udev->data_pages, dpi);
if (likely(page)) {
get_page(page);
lock_page(page);
mutex_unlock(&udev->cmdr_lock);
return page;
}
/*
* Userspace messed up and passed in a address not in the
* data iov passed to it.
*/
pr_err("Invalid addr to data page mapping (dpi %u) on device %s\n",
dpi, udev->name);
mutex_unlock(&udev->cmdr_lock);
return NULL;
}
static void tcmu_vma_open(struct vm_area_struct *vma)
{
struct tcmu_dev *udev = vma->vm_private_data;
pr_debug("vma_open\n");
kref_get(&udev->kref);
}
static void tcmu_vma_close(struct vm_area_struct *vma)
{
struct tcmu_dev *udev = vma->vm_private_data;
pr_debug("vma_close\n");
/* release ref from tcmu_vma_open */
kref_put(&udev->kref, tcmu_dev_kref_release);
}
static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf)
{
struct tcmu_dev *udev = vmf->vma->vm_private_data;
struct uio_info *info = &udev->uio_info;
struct page *page;
unsigned long offset;
void *addr;
vm_fault_t ret = 0;
int mi = tcmu_find_mem_index(vmf->vma);
if (mi < 0)
return VM_FAULT_SIGBUS;
/*
* We need to subtract mi because userspace uses offset = N*PAGE_SIZE
* to use mem[N].
*/
offset = (vmf->pgoff - mi) << PAGE_SHIFT;
if (offset < udev->data_off) {
/* For the vmalloc()ed cmd area pages */
addr = (void *)(unsigned long)info->mem[mi].addr + offset;
page = vmalloc_to_page(addr);
get_page(page);
} else {
uint32_t dpi;
/* For the dynamically growing data area pages */
dpi = (offset - udev->data_off) / PAGE_SIZE;
page = tcmu_try_get_data_page(udev, dpi);
if (!page)
return VM_FAULT_SIGBUS;
ret = VM_FAULT_LOCKED;
}
vmf->page = page;
return ret;
}
static const struct vm_operations_struct tcmu_vm_ops = {
.open = tcmu_vma_open,
.close = tcmu_vma_close,
.fault = tcmu_vma_fault,
};
static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
{
struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP);
vma->vm_ops = &tcmu_vm_ops;
vma->vm_private_data = udev;
/* Ensure the mmap is exactly the right size */
if (vma_pages(vma) != udev->mmap_pages)
return -EINVAL;
tcmu_vma_open(vma);
return 0;
}
static int tcmu_open(struct uio_info *info, struct inode *inode)
{
struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
/* O_EXCL not supported for char devs, so fake it? */
if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags))
return -EBUSY;
udev->inode = inode;
pr_debug("open\n");
return 0;
}
static int tcmu_release(struct uio_info *info, struct inode *inode)
{
struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
struct tcmu_cmd *cmd;
unsigned long i;
bool freed = false;
mutex_lock(&udev->cmdr_lock);
xa_for_each(&udev->commands, i, cmd) {
/* Cmds with KEEP_BUF set are no longer on the ring, but
* userspace still holds the data buffer. If userspace closes
* we implicitly free these cmds and buffers, since after new
* open the (new ?) userspace cannot find the cmd in the ring
* and thus never will release the buffer by writing cmd_id to
* free_kept_buf action attribute.
*/
if (!test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags))
continue;
pr_debug("removing KEEP_BUF cmd %u on dev %s from ring\n",
cmd->cmd_id, udev->name);
freed = true;
xa_erase(&udev->commands, i);
tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
tcmu_free_cmd(cmd);
}
/*
* We only freed data space, not ring space. Therefore we dont call
* run_tmr_queue, but call run_qfull_queue if tmr_list is empty.
*/
if (freed && list_empty(&udev->tmr_queue))
run_qfull_queue(udev, false);
mutex_unlock(&udev->cmdr_lock);
clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags);
pr_debug("close\n");
return 0;
}
static int tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd)
{
struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
if (!tcmu_kern_cmd_reply_supported)
return 0;
if (udev->nl_reply_supported <= 0)
return 0;
mutex_lock(&tcmu_nl_cmd_mutex);
if (tcmu_netlink_blocked) {
mutex_unlock(&tcmu_nl_cmd_mutex);
pr_warn("Failing nl cmd %d on %s. Interface is blocked.\n", cmd,
udev->name);
return -EAGAIN;
}
if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
mutex_unlock(&tcmu_nl_cmd_mutex);
pr_warn("netlink cmd %d already executing on %s\n",
nl_cmd->cmd, udev->name);
return -EBUSY;
}
memset(nl_cmd, 0, sizeof(*nl_cmd));
nl_cmd->cmd = cmd;
nl_cmd->udev = udev;
init_completion(&nl_cmd->complete);
INIT_LIST_HEAD(&nl_cmd->nl_list);
list_add_tail(&nl_cmd->nl_list, &tcmu_nl_cmd_list);
mutex_unlock(&tcmu_nl_cmd_mutex);
return 0;
}
static void tcmu_destroy_genl_cmd_reply(struct tcmu_dev *udev)
{
struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
if (!tcmu_kern_cmd_reply_supported)
return;
if (udev->nl_reply_supported <= 0)
return;
mutex_lock(&tcmu_nl_cmd_mutex);
list_del(&nl_cmd->nl_list);
memset(nl_cmd, 0, sizeof(*nl_cmd));
mutex_unlock(&tcmu_nl_cmd_mutex);
}
static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev)
{
struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
int ret;
if (!tcmu_kern_cmd_reply_supported)
return 0;
if (udev->nl_reply_supported <= 0)
return 0;
pr_debug("sleeping for nl reply\n");
wait_for_completion(&nl_cmd->complete);
mutex_lock(&tcmu_nl_cmd_mutex);
nl_cmd->cmd = TCMU_CMD_UNSPEC;
ret = nl_cmd->status;
mutex_unlock(&tcmu_nl_cmd_mutex);
return ret;
}
static int tcmu_netlink_event_init(struct tcmu_dev *udev,
enum tcmu_genl_cmd cmd,
struct sk_buff **buf, void **hdr)
{
struct sk_buff *skb;
void *msg_header;
int ret = -ENOMEM;
skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return ret;
msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd);
if (!msg_header)
goto free_skb;
ret = nla_put_string(skb, TCMU_ATTR_DEVICE, udev->uio_info.name);
if (ret < 0)
goto free_skb;
ret = nla_put_u32(skb, TCMU_ATTR_MINOR, udev->uio_info.uio_dev->minor);
if (ret < 0)
goto free_skb;
ret = nla_put_u32(skb, TCMU_ATTR_DEVICE_ID, udev->se_dev.dev_index);
if (ret < 0)
goto free_skb;
*buf = skb;
*hdr = msg_header;
return ret;
free_skb:
nlmsg_free(skb);
return ret;
}
static int tcmu_netlink_event_send(struct tcmu_dev *udev,
enum tcmu_genl_cmd cmd,
struct sk_buff *skb, void *msg_header)
{
int ret;
genlmsg_end(skb, msg_header);
ret = tcmu_init_genl_cmd_reply(udev, cmd);
if (ret) {
nlmsg_free(skb);
return ret;
}
ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
TCMU_MCGRP_CONFIG, GFP_KERNEL);
/* Wait during an add as the listener may not be up yet */
if (ret == 0 ||
(ret == -ESRCH && cmd == TCMU_CMD_ADDED_DEVICE))
return tcmu_wait_genl_cmd_reply(udev);
else
tcmu_destroy_genl_cmd_reply(udev);
return ret;
}
static int tcmu_send_dev_add_event(struct tcmu_dev *udev)
{
struct sk_buff *skb = NULL;
void *msg_header = NULL;
int ret = 0;
ret = tcmu_netlink_event_init(udev, TCMU_CMD_ADDED_DEVICE, &skb,
&msg_header);
if (ret < 0)
return ret;
return tcmu_netlink_event_send(udev, TCMU_CMD_ADDED_DEVICE, skb,
msg_header);
}
static int tcmu_send_dev_remove_event(struct tcmu_dev *udev)
{
struct sk_buff *skb = NULL;
void *msg_header = NULL;
int ret = 0;
ret = tcmu_netlink_event_init(udev, TCMU_CMD_REMOVED_DEVICE,
&skb, &msg_header);
if (ret < 0)
return ret;
return tcmu_netlink_event_send(udev, TCMU_CMD_REMOVED_DEVICE,
skb, msg_header);
}
static int tcmu_update_uio_info(struct tcmu_dev *udev)
{
struct tcmu_hba *hba = udev->hba->hba_ptr;
struct uio_info *info;
char *str;
info = &udev->uio_info;
if (udev->dev_config[0])
str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s/%s", hba->host_id,
udev->name, udev->dev_config);
else
str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s", hba->host_id,
udev->name);
if (!str)
return -ENOMEM;
/* If the old string exists, free it */
kfree(info->name);
info->name = str;
return 0;
}
static int tcmu_configure_device(struct se_device *dev)
{
struct tcmu_dev *udev = TCMU_DEV(dev);
struct uio_info *info;
struct tcmu_mailbox *mb;
size_t data_size;
int ret = 0;
ret = tcmu_update_uio_info(udev);
if (ret)
return ret;
info = &udev->uio_info;
mutex_lock(&udev->cmdr_lock);
udev->data_bitmap = bitmap_zalloc(udev->max_blocks, GFP_KERNEL);
mutex_unlock(&udev->cmdr_lock);
if (!udev->data_bitmap) {
ret = -ENOMEM;
goto err_bitmap_alloc;
}
mb = vzalloc(udev->cmdr_size + CMDR_OFF);
if (!mb) {
ret = -ENOMEM;
goto err_vzalloc;
}
/* mailbox fits in first part of CMDR space */
udev->mb_addr = mb;
udev->cmdr = (void *)mb + CMDR_OFF;
udev->data_off = udev->cmdr_size + CMDR_OFF;
data_size = TCMU_MBS_TO_PAGES(udev->data_area_mb) << PAGE_SHIFT;
udev->mmap_pages = (data_size + udev->cmdr_size + CMDR_OFF) >> PAGE_SHIFT;
udev->data_blk_size = udev->data_pages_per_blk * PAGE_SIZE;
udev->dbi_thresh = 0; /* Default in Idle state */
/* Initialise the mailbox of the ring buffer */
mb->version = TCMU_MAILBOX_VERSION;
mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC |
TCMU_MAILBOX_FLAG_CAP_READ_LEN |
TCMU_MAILBOX_FLAG_CAP_TMR |
TCMU_MAILBOX_FLAG_CAP_KEEP_BUF;
mb->cmdr_off = CMDR_OFF;
mb->cmdr_size = udev->cmdr_size;
WARN_ON(!PAGE_ALIGNED(udev->data_off));
WARN_ON(data_size % PAGE_SIZE);
info->version = __stringify(TCMU_MAILBOX_VERSION);
info->mem[0].name = "tcm-user command & data buffer";
info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr;
info->mem[0].size = data_size + udev->cmdr_size + CMDR_OFF;
info->mem[0].memtype = UIO_MEM_NONE;
info->irqcontrol = tcmu_irqcontrol;
info->irq = UIO_IRQ_CUSTOM;
info->mmap = tcmu_mmap;
info->open = tcmu_open;
info->release = tcmu_release;
ret = uio_register_device(tcmu_root_device, info);
if (ret)
goto err_register;
/* User can set hw_block_size before enable the device */
if (dev->dev_attrib.hw_block_size == 0)
dev->dev_attrib.hw_block_size = 512;
/* Other attributes can be configured in userspace */
if (!dev->dev_attrib.hw_max_sectors)
dev->dev_attrib.hw_max_sectors = 128;
if (!dev->dev_attrib.emulate_write_cache)
dev->dev_attrib.emulate_write_cache = 0;
dev->dev_attrib.hw_queue_depth = 128;
/* If user didn't explicitly disable netlink reply support, use
* module scope setting.
*/
if (udev->nl_reply_supported >= 0)
udev->nl_reply_supported = tcmu_kern_cmd_reply_supported;
/*
* Get a ref incase userspace does a close on the uio device before
* LIO has initiated tcmu_free_device.
*/
kref_get(&udev->kref);
ret = tcmu_send_dev_add_event(udev);
if (ret)
goto err_netlink;
mutex_lock(&root_udev_mutex);
list_add(&udev->node, &root_udev);
mutex_unlock(&root_udev_mutex);
return 0;
err_netlink:
kref_put(&udev->kref, tcmu_dev_kref_release);
uio_unregister_device(&udev->uio_info);
err_register:
vfree(udev->mb_addr);
udev->mb_addr = NULL;
err_vzalloc:
bitmap_free(udev->data_bitmap);
udev->data_bitmap = NULL;
err_bitmap_alloc:
kfree(info->name);
info->name = NULL;
return ret;
}
static void tcmu_free_device(struct se_device *dev)
{
struct tcmu_dev *udev = TCMU_DEV(dev);
/* release ref from init */
kref_put(&udev->kref, tcmu_dev_kref_release);
}
static void tcmu_destroy_device(struct se_device *dev)
{
struct tcmu_dev *udev = TCMU_DEV(dev);
del_timer_sync(&udev->cmd_timer);
del_timer_sync(&udev->qfull_timer);
mutex_lock(&root_udev_mutex);
list_del(&udev->node);
mutex_unlock(&root_udev_mutex);
tcmu_send_dev_remove_event(udev);
uio_unregister_device(&udev->uio_info);
/* release ref from configure */
kref_put(&udev->kref, tcmu_dev_kref_release);
}
static void tcmu_unblock_dev(struct tcmu_dev *udev)
{
mutex_lock(&udev->cmdr_lock);
clear_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags);
mutex_unlock(&udev->cmdr_lock);
}
static void tcmu_block_dev(struct tcmu_dev *udev)
{
mutex_lock(&udev->cmdr_lock);
if (test_and_set_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
goto unlock;
/* complete IO that has executed successfully */
tcmu_handle_completions(udev);
/* fail IO waiting to be queued */
run_qfull_queue(udev, true);
unlock:
mutex_unlock(&udev->cmdr_lock);
}
static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
{
struct tcmu_mailbox *mb;
struct tcmu_cmd *cmd;
unsigned long i;
mutex_lock(&udev->cmdr_lock);
xa_for_each(&udev->commands, i, cmd) {
pr_debug("removing cmd %u on dev %s from ring %s\n",
cmd->cmd_id, udev->name,
test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) ?
"(is expired)" :
(test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags) ?
"(is keep buffer)" : ""));
xa_erase(&udev->commands, i);
if (!test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) &&
!test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
WARN_ON(!cmd->se_cmd);
list_del_init(&cmd->queue_entry);
cmd->se_cmd->priv = NULL;
if (err_level == 1) {
/*
* Userspace was not able to start the
* command or it is retryable.
*/
target_complete_cmd(cmd->se_cmd, SAM_STAT_BUSY);
} else {
/* hard failure */
target_complete_cmd(cmd->se_cmd,
SAM_STAT_CHECK_CONDITION);
}
}
tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
tcmu_free_cmd(cmd);
}
mb = udev->mb_addr;
tcmu_flush_dcache_range(mb, sizeof(*mb));
pr_debug("mb last %u head %u tail %u\n", udev->cmdr_last_cleaned,
mb->cmd_tail, mb->cmd_head);
udev->cmdr_last_cleaned = 0;
mb->cmd_tail = 0;
mb->cmd_head = 0;
tcmu_flush_dcache_range(mb, sizeof(*mb));
clear_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
del_timer(&udev->cmd_timer);
/*
* ring is empty and qfull queue never contains aborted commands.
* So TMRs in tmr queue do not contain relevant cmd_ids.
* After a ring reset userspace should do a fresh start, so
* even LUN RESET message is no longer relevant.
* Therefore remove all TMRs from qfull queue
*/
tcmu_remove_all_queued_tmr(udev);
run_qfull_queue(udev, false);
mutex_unlock(&udev->cmdr_lock);
}
enum {
Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_data_pages_per_blk,
Opt_cmd_ring_size_mb, Opt_err,
};
static match_table_t tokens = {
{Opt_dev_config, "dev_config=%s"},
{Opt_dev_size, "dev_size=%s"},
{Opt_hw_block_size, "hw_block_size=%d"},
{Opt_hw_max_sectors, "hw_max_sectors=%d"},
{Opt_nl_reply_supported, "nl_reply_supported=%d"},
{Opt_max_data_area_mb, "max_data_area_mb=%d"},
{Opt_data_pages_per_blk, "data_pages_per_blk=%d"},
{Opt_cmd_ring_size_mb, "cmd_ring_size_mb=%d"},
{Opt_err, NULL}
};
static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)
{
int val, ret;
ret = match_int(arg, &val);
if (ret < 0) {
pr_err("match_int() failed for dev attrib. Error %d.\n",
ret);
return ret;
}
if (val <= 0) {
pr_err("Invalid dev attrib value %d. Must be greater than zero.\n",
val);
return -EINVAL;
}
*dev_attrib = val;
return 0;
}
static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
{
int val, ret;
uint32_t pages_per_blk = udev->data_pages_per_blk;
ret = match_int(arg, &val);
if (ret < 0) {
pr_err("match_int() failed for max_data_area_mb=. Error %d.\n",
ret);
return ret;
}
if (val <= 0) {
pr_err("Invalid max_data_area %d.\n", val);
return -EINVAL;
}
if (val > TCMU_PAGES_TO_MBS(tcmu_global_max_pages)) {
pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
val, TCMU_PAGES_TO_MBS(tcmu_global_max_pages));
val = TCMU_PAGES_TO_MBS(tcmu_global_max_pages);
}
if (TCMU_MBS_TO_PAGES(val) < pages_per_blk) {
pr_err("Invalid max_data_area %d (%zu pages): smaller than data_pages_per_blk (%u pages).\n",
val, TCMU_MBS_TO_PAGES(val), pages_per_blk);
return -EINVAL;
}
mutex_lock(&udev->cmdr_lock);
if (udev->data_bitmap) {
pr_err("Cannot set max_data_area_mb after it has been enabled.\n");
ret = -EINVAL;
goto unlock;
}
udev->data_area_mb = val;
udev->max_blocks = TCMU_MBS_TO_PAGES(val) / pages_per_blk;
unlock:
mutex_unlock(&udev->cmdr_lock);
return ret;
}
static int tcmu_set_data_pages_per_blk(struct tcmu_dev *udev, substring_t *arg)
{
int val, ret;
ret = match_int(arg, &val);
if (ret < 0) {
pr_err("match_int() failed for data_pages_per_blk=. Error %d.\n",
ret);
return ret;
}
if (val > TCMU_MBS_TO_PAGES(udev->data_area_mb)) {
pr_err("Invalid data_pages_per_blk %d: greater than max_data_area_mb %d -> %zd pages).\n",
val, udev->data_area_mb,
TCMU_MBS_TO_PAGES(udev->data_area_mb));
return -EINVAL;
}
mutex_lock(&udev->cmdr_lock);
if (udev->data_bitmap) {
pr_err("Cannot set data_pages_per_blk after it has been enabled.\n");
ret = -EINVAL;
goto unlock;
}
udev->data_pages_per_blk = val;
udev->max_blocks = TCMU_MBS_TO_PAGES(udev->data_area_mb) / val;
unlock:
mutex_unlock(&udev->cmdr_lock);
return ret;
}
static int tcmu_set_cmd_ring_size(struct tcmu_dev *udev, substring_t *arg)
{
int val, ret;
ret = match_int(arg, &val);
if (ret < 0) {
pr_err("match_int() failed for cmd_ring_size_mb=. Error %d.\n",
ret);
return ret;
}
if (val <= 0) {
pr_err("Invalid cmd_ring_size_mb %d.\n", val);
return -EINVAL;
}
mutex_lock(&udev->cmdr_lock);
if (udev->data_bitmap) {
pr_err("Cannot set cmd_ring_size_mb after it has been enabled.\n");
ret = -EINVAL;
goto unlock;
}
udev->cmdr_size = (val << 20) - CMDR_OFF;
if (val > (MB_CMDR_SIZE_DEF >> 20)) {
pr_err("%d is too large. Adjusting cmd_ring_size_mb to global limit of %u\n",
val, (MB_CMDR_SIZE_DEF >> 20));
udev->cmdr_size = CMDR_SIZE_DEF;
}
unlock:
mutex_unlock(&udev->cmdr_lock);
return ret;
}
static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
const char *page, ssize_t count)
{
struct tcmu_dev *udev = TCMU_DEV(dev);
char *orig, *ptr, *opts;
substring_t args[MAX_OPT_ARGS];
int ret = 0, token;
opts = kstrdup(page, GFP_KERNEL);
if (!opts)
return -ENOMEM;
orig = opts;
while ((ptr = strsep(&opts, ",\n")) != NULL) {
if (!*ptr)
continue;
token = match_token(ptr, tokens, args);
switch (token) {
case Opt_dev_config:
if (match_strlcpy(udev->dev_config, &args[0],
TCMU_CONFIG_LEN) == 0) {
ret = -EINVAL;
break;
}
pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config);
break;
case Opt_dev_size:
ret = match_u64(&args[0], &udev->dev_size);
if (ret < 0)
pr_err("match_u64() failed for dev_size=. Error %d.\n",
ret);
break;
case Opt_hw_block_size:
ret = tcmu_set_dev_attrib(&args[0],
&(dev->dev_attrib.hw_block_size));
break;
case Opt_hw_max_sectors:
ret = tcmu_set_dev_attrib(&args[0],
&(dev->dev_attrib.hw_max_sectors));
break;
case Opt_nl_reply_supported:
ret = match_int(&args[0], &udev->nl_reply_supported);
if (ret < 0)
pr_err("match_int() failed for nl_reply_supported=. Error %d.\n",
ret);
break;
case Opt_max_data_area_mb:
ret = tcmu_set_max_blocks_param(udev, &args[0]);
break;
case Opt_data_pages_per_blk:
ret = tcmu_set_data_pages_per_blk(udev, &args[0]);
break;
case Opt_cmd_ring_size_mb:
ret = tcmu_set_cmd_ring_size(udev, &args[0]);
break;
default:
break;
}
if (ret)
break;
}
kfree(orig);
return (!ret) ? count : ret;
}
static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
{
struct tcmu_dev *udev = TCMU_DEV(dev);
ssize_t bl = 0;
bl = sprintf(b + bl, "Config: %s ",
udev->dev_config[0] ? udev->dev_config : "NULL");
bl += sprintf(b + bl, "Size: %llu ", udev->dev_size);
bl += sprintf(b + bl, "MaxDataAreaMB: %u ", udev->data_area_mb);
bl += sprintf(b + bl, "DataPagesPerBlk: %u ", udev->data_pages_per_blk);
bl += sprintf(b + bl, "CmdRingSizeMB: %u\n",
(udev->cmdr_size + CMDR_OFF) >> 20);
return bl;
}
static sector_t tcmu_get_blocks(struct se_device *dev)
{
struct tcmu_dev *udev = TCMU_DEV(dev);
return div_u64(udev->dev_size - dev->dev_attrib.block_size,
dev->dev_attrib.block_size);
}
static sense_reason_t
tcmu_parse_cdb(struct se_cmd *cmd)
{
return passthrough_parse_cdb(cmd, tcmu_queue_cmd);
}
static ssize_t tcmu_cmd_time_out_show(struct config_item *item, char *page)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
return snprintf(page, PAGE_SIZE, "%lu\n", udev->cmd_time_out / MSEC_PER_SEC);
}
static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *page,
size_t count)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = container_of(da->da_dev,
struct tcmu_dev, se_dev);
u32 val;
int ret;
if (da->da_dev->export_count) {
pr_err("Unable to set tcmu cmd_time_out while exports exist\n");
return -EINVAL;
}
ret = kstrtou32(page, 0, &val);
if (ret < 0)
return ret;
udev->cmd_time_out = val * MSEC_PER_SEC;
return count;
}
CONFIGFS_ATTR(tcmu_, cmd_time_out);
static ssize_t tcmu_qfull_time_out_show(struct config_item *item, char *page)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
return snprintf(page, PAGE_SIZE, "%ld\n", udev->qfull_time_out <= 0 ?
udev->qfull_time_out :
udev->qfull_time_out / MSEC_PER_SEC);
}
static ssize_t tcmu_qfull_time_out_store(struct config_item *item,
const char *page, size_t count)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
s32 val;
int ret;
ret = kstrtos32(page, 0, &val);
if (ret < 0)
return ret;
if (val >= 0) {
udev->qfull_time_out = val * MSEC_PER_SEC;
} else if (val == -1) {
udev->qfull_time_out = val;
} else {
printk(KERN_ERR "Invalid qfull timeout value %d\n", val);
return -EINVAL;
}
return count;
}
CONFIGFS_ATTR(tcmu_, qfull_time_out);
static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
return snprintf(page, PAGE_SIZE, "%u\n", udev->data_area_mb);
}
CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb);
static ssize_t tcmu_data_pages_per_blk_show(struct config_item *item,
char *page)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
return snprintf(page, PAGE_SIZE, "%u\n", udev->data_pages_per_blk);
}
CONFIGFS_ATTR_RO(tcmu_, data_pages_per_blk);
static ssize_t tcmu_cmd_ring_size_mb_show(struct config_item *item, char *page)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
return snprintf(page, PAGE_SIZE, "%u\n",
(udev->cmdr_size + CMDR_OFF) >> 20);
}
CONFIGFS_ATTR_RO(tcmu_, cmd_ring_size_mb);
static ssize_t tcmu_dev_config_show(struct config_item *item, char *page)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
return snprintf(page, PAGE_SIZE, "%s\n", udev->dev_config);
}
static int tcmu_send_dev_config_event(struct tcmu_dev *udev,
const char *reconfig_data)
{
struct sk_buff *skb = NULL;
void *msg_header = NULL;
int ret = 0;
ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
&skb, &msg_header);
if (ret < 0)
return ret;
ret = nla_put_string(skb, TCMU_ATTR_DEV_CFG, reconfig_data);
if (ret < 0) {
nlmsg_free(skb);
return ret;
}
return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
skb, msg_header);
}
static ssize_t tcmu_dev_config_store(struct config_item *item, const char *page,
size_t count)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
int ret, len;
len = strlen(page);
if (!len || len > TCMU_CONFIG_LEN - 1)
return -EINVAL;
/* Check if device has been configured before */
if (target_dev_configured(&udev->se_dev)) {
ret = tcmu_send_dev_config_event(udev, page);
if (ret) {
pr_err("Unable to reconfigure device\n");
return ret;
}
strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
ret = tcmu_update_uio_info(udev);
if (ret)
return ret;
return count;
}
strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
return count;
}
CONFIGFS_ATTR(tcmu_, dev_config);
static ssize_t tcmu_dev_size_show(struct config_item *item, char *page)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
return snprintf(page, PAGE_SIZE, "%llu\n", udev->dev_size);
}
static int tcmu_send_dev_size_event(struct tcmu_dev *udev, u64 size)
{
struct sk_buff *skb = NULL;
void *msg_header = NULL;
int ret = 0;
ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
&skb, &msg_header);
if (ret < 0)
return ret;
ret = nla_put_u64_64bit(skb, TCMU_ATTR_DEV_SIZE,
size, TCMU_ATTR_PAD);
if (ret < 0) {
nlmsg_free(skb);
return ret;
}
return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
skb, msg_header);
}
static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page,
size_t count)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
u64 val;
int ret;
ret = kstrtou64(page, 0, &val);
if (ret < 0)
return ret;
/* Check if device has been configured before */
if (target_dev_configured(&udev->se_dev)) {
ret = tcmu_send_dev_size_event(udev, val);
if (ret) {
pr_err("Unable to reconfigure device\n");
return ret;
}
}
udev->dev_size = val;
return count;
}
CONFIGFS_ATTR(tcmu_, dev_size);
static ssize_t tcmu_nl_reply_supported_show(struct config_item *item,
char *page)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
return snprintf(page, PAGE_SIZE, "%d\n", udev->nl_reply_supported);
}
static ssize_t tcmu_nl_reply_supported_store(struct config_item *item,
const char *page, size_t count)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
s8 val;
int ret;
ret = kstrtos8(page, 0, &val);
if (ret < 0)
return ret;
udev->nl_reply_supported = val;
return count;
}
CONFIGFS_ATTR(tcmu_, nl_reply_supported);
static ssize_t tcmu_emulate_write_cache_show(struct config_item *item,
char *page)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
return snprintf(page, PAGE_SIZE, "%i\n", da->emulate_write_cache);
}
static int tcmu_send_emulate_write_cache(struct tcmu_dev *udev, u8 val)
{
struct sk_buff *skb = NULL;
void *msg_header = NULL;
int ret = 0;
ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
&skb, &msg_header);
if (ret < 0)
return ret;
ret = nla_put_u8(skb, TCMU_ATTR_WRITECACHE, val);
if (ret < 0) {
nlmsg_free(skb);
return ret;
}
return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
skb, msg_header);
}
static ssize_t tcmu_emulate_write_cache_store(struct config_item *item,
const char *page, size_t count)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
u8 val;
int ret;
ret = kstrtou8(page, 0, &val);
if (ret < 0)
return ret;
/* Check if device has been configured before */
if (target_dev_configured(&udev->se_dev)) {
ret = tcmu_send_emulate_write_cache(udev, val);
if (ret) {
pr_err("Unable to reconfigure device\n");
return ret;
}
}
da->emulate_write_cache = val;
return count;
}
CONFIGFS_ATTR(tcmu_, emulate_write_cache);
static ssize_t tcmu_tmr_notification_show(struct config_item *item, char *page)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
return snprintf(page, PAGE_SIZE, "%i\n",
test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags));
}
static ssize_t tcmu_tmr_notification_store(struct config_item *item,
const char *page, size_t count)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
u8 val;
int ret;
ret = kstrtou8(page, 0, &val);
if (ret < 0)
return ret;
if (val > 1)
return -EINVAL;
if (val)
set_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
else
clear_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
return count;
}
CONFIGFS_ATTR(tcmu_, tmr_notification);
static ssize_t tcmu_block_dev_show(struct config_item *item, char *page)
{
struct se_device *se_dev = container_of(to_config_group(item),
struct se_device,
dev_action_group);
struct tcmu_dev *udev = TCMU_DEV(se_dev);
if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
return snprintf(page, PAGE_SIZE, "%s\n", "blocked");
else
return snprintf(page, PAGE_SIZE, "%s\n", "unblocked");
}
static ssize_t tcmu_block_dev_store(struct config_item *item, const char *page,
size_t count)
{
struct se_device *se_dev = container_of(to_config_group(item),
struct se_device,
dev_action_group);
struct tcmu_dev *udev = TCMU_DEV(se_dev);
u8 val;
int ret;
if (!target_dev_configured(&udev->se_dev)) {
pr_err("Device is not configured.\n");
return -EINVAL;
}
ret = kstrtou8(page, 0, &val);
if (ret < 0)
return ret;
if (val > 1) {
pr_err("Invalid block value %d\n", val);
return -EINVAL;
}
if (!val)
tcmu_unblock_dev(udev);
else
tcmu_block_dev(udev);
return count;
}
CONFIGFS_ATTR(tcmu_, block_dev);
static ssize_t tcmu_reset_ring_store(struct config_item *item, const char *page,
size_t count)
{
struct se_device *se_dev = container_of(to_config_group(item),
struct se_device,
dev_action_group);
struct tcmu_dev *udev = TCMU_DEV(se_dev);
u8 val;
int ret;
if (!target_dev_configured(&udev->se_dev)) {
pr_err("Device is not configured.\n");
return -EINVAL;
}
ret = kstrtou8(page, 0, &val);
if (ret < 0)
return ret;
if (val != 1 && val != 2) {
pr_err("Invalid reset ring value %d\n", val);
return -EINVAL;
}
tcmu_reset_ring(udev, val);
return count;
}
CONFIGFS_ATTR_WO(tcmu_, reset_ring);
static ssize_t tcmu_free_kept_buf_store(struct config_item *item, const char *page,
size_t count)
{
struct se_device *se_dev = container_of(to_config_group(item),
struct se_device,
dev_action_group);
struct tcmu_dev *udev = TCMU_DEV(se_dev);
struct tcmu_cmd *cmd;
u16 cmd_id;
int ret;
if (!target_dev_configured(&udev->se_dev)) {
pr_err("Device is not configured.\n");
return -EINVAL;
}
ret = kstrtou16(page, 0, &cmd_id);
if (ret < 0)
return ret;
mutex_lock(&udev->cmdr_lock);
{
XA_STATE(xas, &udev->commands, cmd_id);
xas_lock(&xas);
cmd = xas_load(&xas);
if (!cmd) {
pr_err("free_kept_buf: cmd_id %d not found\n", cmd_id);
count = -EINVAL;
xas_unlock(&xas);
goto out_unlock;
}
if (!test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
pr_err("free_kept_buf: cmd_id %d was not completed with KEEP_BUF\n",
cmd_id);
count = -EINVAL;
xas_unlock(&xas);
goto out_unlock;
}
xas_store(&xas, NULL);
xas_unlock(&xas);
}
tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
tcmu_free_cmd(cmd);
/*
* We only freed data space, not ring space. Therefore we dont call
* run_tmr_queue, but call run_qfull_queue if tmr_list is empty.
*/
if (list_empty(&udev->tmr_queue))
run_qfull_queue(udev, false);
out_unlock:
mutex_unlock(&udev->cmdr_lock);
return count;
}
CONFIGFS_ATTR_WO(tcmu_, free_kept_buf);
static struct configfs_attribute *tcmu_attrib_attrs[] = {
&tcmu_attr_cmd_time_out,
&tcmu_attr_qfull_time_out,
&tcmu_attr_max_data_area_mb,
&tcmu_attr_data_pages_per_blk,
&tcmu_attr_cmd_ring_size_mb,
&tcmu_attr_dev_config,
&tcmu_attr_dev_size,
&tcmu_attr_emulate_write_cache,
&tcmu_attr_tmr_notification,
&tcmu_attr_nl_reply_supported,
NULL,
};
static struct configfs_attribute **tcmu_attrs;
static struct configfs_attribute *tcmu_action_attrs[] = {
&tcmu_attr_block_dev,
&tcmu_attr_reset_ring,
&tcmu_attr_free_kept_buf,
NULL,
};
static struct target_backend_ops tcmu_ops = {
.name = "user",
.owner = THIS_MODULE,
.transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH,
.transport_flags_changeable = TRANSPORT_FLAG_PASSTHROUGH_PGR |
TRANSPORT_FLAG_PASSTHROUGH_ALUA,
.attach_hba = tcmu_attach_hba,
.detach_hba = tcmu_detach_hba,
.alloc_device = tcmu_alloc_device,
.configure_device = tcmu_configure_device,
.destroy_device = tcmu_destroy_device,
.free_device = tcmu_free_device,
.unplug_device = tcmu_unplug_device,
.plug_device = tcmu_plug_device,
.parse_cdb = tcmu_parse_cdb,
.tmr_notify = tcmu_tmr_notify,
.set_configfs_dev_params = tcmu_set_configfs_dev_params,
.show_configfs_dev_params = tcmu_show_configfs_dev_params,
.get_device_type = sbc_get_device_type,
.get_blocks = tcmu_get_blocks,
.tb_dev_action_attrs = tcmu_action_attrs,
};
static void find_free_blocks(void)
{
struct tcmu_dev *udev;
loff_t off;
u32 pages_freed, total_pages_freed = 0;
u32 start, end, block, total_blocks_freed = 0;
if (atomic_read(&global_page_count) <= tcmu_global_max_pages)
return;
mutex_lock(&root_udev_mutex);
list_for_each_entry(udev, &root_udev, node) {
mutex_lock(&udev->cmdr_lock);
if (!target_dev_configured(&udev->se_dev)) {
mutex_unlock(&udev->cmdr_lock);
continue;
}
/* Try to complete the finished commands first */
if (tcmu_handle_completions(udev))
run_qfull_queue(udev, false);
/* Skip the udevs in idle */
if (!udev->dbi_thresh) {
mutex_unlock(&udev->cmdr_lock);
continue;
}
end = udev->dbi_max + 1;
block = find_last_bit(udev->data_bitmap, end);
if (block == udev->dbi_max) {
/*
* The last bit is dbi_max, so it is not possible
* reclaim any blocks.
*/
mutex_unlock(&udev->cmdr_lock);
continue;
} else if (block == end) {
/* The current udev will goto idle state */
udev->dbi_thresh = start = 0;
udev->dbi_max = 0;
} else {
udev->dbi_thresh = start = block + 1;
udev->dbi_max = block;
}
/*
* Release the block pages.
*
* Also note that since tcmu_vma_fault() gets an extra page
* refcount, tcmu_blocks_release() won't free pages if pages
* are mapped. This means it is safe to call
* tcmu_blocks_release() before unmap_mapping_range() which
* drops the refcount of any pages it unmaps and thus releases
* them.
*/
pages_freed = tcmu_blocks_release(udev, start, end - 1);
/* Here will truncate the data area from off */
off = udev->data_off + (loff_t)start * udev->data_blk_size;
unmap_mapping_range(udev->inode->i_mapping, off, 0, 1);
mutex_unlock(&udev->cmdr_lock);
total_pages_freed += pages_freed;
total_blocks_freed += end - start;
pr_debug("Freed %u pages (total %u) from %u blocks (total %u) from %s.\n",
pages_freed, total_pages_freed, end - start,
total_blocks_freed, udev->name);
}
mutex_unlock(&root_udev_mutex);
if (atomic_read(&global_page_count) > tcmu_global_max_pages)
schedule_delayed_work(&tcmu_unmap_work, msecs_to_jiffies(5000));
}
static void check_timedout_devices(void)
{
struct tcmu_dev *udev, *tmp_dev;
struct tcmu_cmd *cmd, *tmp_cmd;
LIST_HEAD(devs);
spin_lock_bh(&timed_out_udevs_lock);
list_splice_init(&timed_out_udevs, &devs);
list_for_each_entry_safe(udev, tmp_dev, &devs, timedout_entry) {
list_del_init(&udev->timedout_entry);
spin_unlock_bh(&timed_out_udevs_lock);
mutex_lock(&udev->cmdr_lock);
/*
* If cmd_time_out is disabled but qfull is set deadline
* will only reflect the qfull timeout. Ignore it.
*/
if (udev->cmd_time_out) {
list_for_each_entry_safe(cmd, tmp_cmd,
&udev->inflight_queue,
queue_entry) {
tcmu_check_expired_ring_cmd(cmd);
}
tcmu_set_next_deadline(&udev->inflight_queue,
&udev->cmd_timer);
}
list_for_each_entry_safe(cmd, tmp_cmd, &udev->qfull_queue,
queue_entry) {
tcmu_check_expired_queue_cmd(cmd);
}
tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
mutex_unlock(&udev->cmdr_lock);
spin_lock_bh(&timed_out_udevs_lock);
}
spin_unlock_bh(&timed_out_udevs_lock);
}
static void tcmu_unmap_work_fn(struct work_struct *work)
{
check_timedout_devices();
find_free_blocks();
}
static int __init tcmu_module_init(void)
{
int ret, i, k, len = 0;
BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn);
tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
sizeof(struct tcmu_cmd),
__alignof__(struct tcmu_cmd),
0, NULL);
if (!tcmu_cmd_cache)
return -ENOMEM;
tcmu_root_device = root_device_register("tcm_user");
if (IS_ERR(tcmu_root_device)) {
ret = PTR_ERR(tcmu_root_device);
goto out_free_cache;
}
ret = genl_register_family(&tcmu_genl_family);
if (ret < 0) {
goto out_unreg_device;
}
for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
len += sizeof(struct configfs_attribute *);
for (i = 0; passthrough_pr_attrib_attrs[i] != NULL; i++)
len += sizeof(struct configfs_attribute *);
for (i = 0; tcmu_attrib_attrs[i] != NULL; i++)
len += sizeof(struct configfs_attribute *);
len += sizeof(struct configfs_attribute *);
tcmu_attrs = kzalloc(len, GFP_KERNEL);
if (!tcmu_attrs) {
ret = -ENOMEM;
goto out_unreg_genl;
}
for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
tcmu_attrs[i] = passthrough_attrib_attrs[i];
for (k = 0; passthrough_pr_attrib_attrs[k] != NULL; k++)
tcmu_attrs[i++] = passthrough_pr_attrib_attrs[k];
for (k = 0; tcmu_attrib_attrs[k] != NULL; k++)
tcmu_attrs[i++] = tcmu_attrib_attrs[k];
tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
ret = transport_backend_register(&tcmu_ops);
if (ret)
goto out_attrs;
return 0;
out_attrs:
kfree(tcmu_attrs);
out_unreg_genl:
genl_unregister_family(&tcmu_genl_family);
out_unreg_device:
root_device_unregister(tcmu_root_device);
out_free_cache:
kmem_cache_destroy(tcmu_cmd_cache);
return ret;
}
static void __exit tcmu_module_exit(void)
{
cancel_delayed_work_sync(&tcmu_unmap_work);
target_backend_unregister(&tcmu_ops);
kfree(tcmu_attrs);
genl_unregister_family(&tcmu_genl_family);
root_device_unregister(tcmu_root_device);
kmem_cache_destroy(tcmu_cmd_cache);
}
MODULE_DESCRIPTION("TCM USER subsystem plugin");
MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
MODULE_LICENSE("GPL");
module_init(tcmu_module_init);
module_exit(tcmu_module_exit);