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Diffstat (limited to '')
| -rw-r--r-- | drivers/target/target_core_user.c | 3393 |
1 files changed, 3393 insertions, 0 deletions
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c new file mode 100644 index 000000000..2940559c3 --- /dev/null +++ b/drivers/target/target_core_user.c @@ -0,0 +1,3393 @@ +// 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); + + vma->vm_flags |= 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); |