[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/drivers/block/null_blk.c b/src/kernel/linux/v4.14/drivers/block/null_blk.c
new file mode 100644
index 0000000..b499e72
--- /dev/null
+++ b/src/kernel/linux/v4.14/drivers/block/null_blk.c
@@ -0,0 +1,2062 @@
+/*
+ * Add configfs and memory store: Kyungchan Koh <kkc6196@fb.com> and
+ * Shaohua Li <shli@fb.com>
+ */
+#include <linux/module.h>
+
+#include <linux/moduleparam.h>
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/blkdev.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/blk-mq.h>
+#include <linux/hrtimer.h>
+#include <linux/lightnvm.h>
+#include <linux/configfs.h>
+#include <linux/badblocks.h>
+
+#define PAGE_SECTORS_SHIFT (PAGE_SHIFT - SECTOR_SHIFT)
+#define PAGE_SECTORS (1 << PAGE_SECTORS_SHIFT)
+#define SECTOR_MASK (PAGE_SECTORS - 1)
+
+#define FREE_BATCH 16
+
+#define TICKS_PER_SEC 50ULL
+#define TIMER_INTERVAL (NSEC_PER_SEC / TICKS_PER_SEC)
+
+static inline u64 mb_per_tick(int mbps)
+{
+ return (1 << 20) / TICKS_PER_SEC * ((u64) mbps);
+}
+
+struct nullb_cmd {
+ struct list_head list;
+ struct llist_node ll_list;
+ call_single_data_t csd;
+ struct request *rq;
+ struct bio *bio;
+ unsigned int tag;
+ struct nullb_queue *nq;
+ struct hrtimer timer;
+ blk_status_t error;
+};
+
+struct nullb_queue {
+ unsigned long *tag_map;
+ wait_queue_head_t wait;
+ unsigned int queue_depth;
+ struct nullb_device *dev;
+
+ struct nullb_cmd *cmds;
+};
+
+/*
+ * Status flags for nullb_device.
+ *
+ * CONFIGURED: Device has been configured and turned on. Cannot reconfigure.
+ * UP: Device is currently on and visible in userspace.
+ * THROTTLED: Device is being throttled.
+ * CACHE: Device is using a write-back cache.
+ */
+enum nullb_device_flags {
+ NULLB_DEV_FL_CONFIGURED = 0,
+ NULLB_DEV_FL_UP = 1,
+ NULLB_DEV_FL_THROTTLED = 2,
+ NULLB_DEV_FL_CACHE = 3,
+};
+
+#define MAP_SZ ((PAGE_SIZE >> SECTOR_SHIFT) + 2)
+/*
+ * nullb_page is a page in memory for nullb devices.
+ *
+ * @page: The page holding the data.
+ * @bitmap: The bitmap represents which sector in the page has data.
+ * Each bit represents one block size. For example, sector 8
+ * will use the 7th bit
+ * The highest 2 bits of bitmap are for special purpose. LOCK means the cache
+ * page is being flushing to storage. FREE means the cache page is freed and
+ * should be skipped from flushing to storage. Please see
+ * null_make_cache_space
+ */
+struct nullb_page {
+ struct page *page;
+ DECLARE_BITMAP(bitmap, MAP_SZ);
+};
+#define NULLB_PAGE_LOCK (MAP_SZ - 1)
+#define NULLB_PAGE_FREE (MAP_SZ - 2)
+
+struct nullb_device {
+ struct nullb *nullb;
+ struct config_item item;
+ struct radix_tree_root data; /* data stored in the disk */
+ struct radix_tree_root cache; /* disk cache data */
+ unsigned long flags; /* device flags */
+ unsigned int curr_cache;
+ struct badblocks badblocks;
+
+ unsigned long size; /* device size in MB */
+ unsigned long completion_nsec; /* time in ns to complete a request */
+ unsigned long cache_size; /* disk cache size in MB */
+ unsigned int submit_queues; /* number of submission queues */
+ unsigned int home_node; /* home node for the device */
+ unsigned int queue_mode; /* block interface */
+ unsigned int blocksize; /* block size */
+ unsigned int irqmode; /* IRQ completion handler */
+ unsigned int hw_queue_depth; /* queue depth */
+ unsigned int index; /* index of the disk, only valid with a disk */
+ unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
+ bool use_lightnvm; /* register as a LightNVM device */
+ bool blocking; /* blocking blk-mq device */
+ bool use_per_node_hctx; /* use per-node allocation for hardware context */
+ bool power; /* power on/off the device */
+ bool memory_backed; /* if data is stored in memory */
+ bool discard; /* if support discard */
+};
+
+struct nullb {
+ struct nullb_device *dev;
+ struct list_head list;
+ unsigned int index;
+ struct request_queue *q;
+ struct gendisk *disk;
+ struct nvm_dev *ndev;
+ struct blk_mq_tag_set *tag_set;
+ struct blk_mq_tag_set __tag_set;
+ unsigned int queue_depth;
+ atomic_long_t cur_bytes;
+ struct hrtimer bw_timer;
+ unsigned long cache_flush_pos;
+ spinlock_t lock;
+
+ struct nullb_queue *queues;
+ unsigned int nr_queues;
+ char disk_name[DISK_NAME_LEN];
+};
+
+static LIST_HEAD(nullb_list);
+static struct mutex lock;
+static int null_major;
+static DEFINE_IDA(nullb_indexes);
+static struct kmem_cache *ppa_cache;
+static struct blk_mq_tag_set tag_set;
+
+enum {
+ NULL_IRQ_NONE = 0,
+ NULL_IRQ_SOFTIRQ = 1,
+ NULL_IRQ_TIMER = 2,
+};
+
+enum {
+ NULL_Q_BIO = 0,
+ NULL_Q_RQ = 1,
+ NULL_Q_MQ = 2,
+};
+
+static int g_submit_queues = 1;
+module_param_named(submit_queues, g_submit_queues, int, S_IRUGO);
+MODULE_PARM_DESC(submit_queues, "Number of submission queues");
+
+static int g_home_node = NUMA_NO_NODE;
+module_param_named(home_node, g_home_node, int, S_IRUGO);
+MODULE_PARM_DESC(home_node, "Home node for the device");
+
+static int g_queue_mode = NULL_Q_MQ;
+
+static int null_param_store_val(const char *str, int *val, int min, int max)
+{
+ int ret, new_val;
+
+ ret = kstrtoint(str, 10, &new_val);
+ if (ret)
+ return -EINVAL;
+
+ if (new_val < min || new_val > max)
+ return -EINVAL;
+
+ *val = new_val;
+ return 0;
+}
+
+static int null_set_queue_mode(const char *str, const struct kernel_param *kp)
+{
+ return null_param_store_val(str, &g_queue_mode, NULL_Q_BIO, NULL_Q_MQ);
+}
+
+static const struct kernel_param_ops null_queue_mode_param_ops = {
+ .set = null_set_queue_mode,
+ .get = param_get_int,
+};
+
+device_param_cb(queue_mode, &null_queue_mode_param_ops, &g_queue_mode, S_IRUGO);
+MODULE_PARM_DESC(queue_mode, "Block interface to use (0=bio,1=rq,2=multiqueue)");
+
+static int g_gb = 250;
+module_param_named(gb, g_gb, int, S_IRUGO);
+MODULE_PARM_DESC(gb, "Size in GB");
+
+static int g_bs = 512;
+module_param_named(bs, g_bs, int, S_IRUGO);
+MODULE_PARM_DESC(bs, "Block size (in bytes)");
+
+static int nr_devices = 1;
+module_param(nr_devices, int, S_IRUGO);
+MODULE_PARM_DESC(nr_devices, "Number of devices to register");
+
+static bool g_use_lightnvm;
+module_param_named(use_lightnvm, g_use_lightnvm, bool, S_IRUGO);
+MODULE_PARM_DESC(use_lightnvm, "Register as a LightNVM device");
+
+static bool g_blocking;
+module_param_named(blocking, g_blocking, bool, S_IRUGO);
+MODULE_PARM_DESC(blocking, "Register as a blocking blk-mq driver device");
+
+static bool shared_tags;
+module_param(shared_tags, bool, S_IRUGO);
+MODULE_PARM_DESC(shared_tags, "Share tag set between devices for blk-mq");
+
+static int g_irqmode = NULL_IRQ_SOFTIRQ;
+
+static int null_set_irqmode(const char *str, const struct kernel_param *kp)
+{
+ return null_param_store_val(str, &g_irqmode, NULL_IRQ_NONE,
+ NULL_IRQ_TIMER);
+}
+
+static const struct kernel_param_ops null_irqmode_param_ops = {
+ .set = null_set_irqmode,
+ .get = param_get_int,
+};
+
+device_param_cb(irqmode, &null_irqmode_param_ops, &g_irqmode, S_IRUGO);
+MODULE_PARM_DESC(irqmode, "IRQ completion handler. 0-none, 1-softirq, 2-timer");
+
+static unsigned long g_completion_nsec = 10000;
+module_param_named(completion_nsec, g_completion_nsec, ulong, S_IRUGO);
+MODULE_PARM_DESC(completion_nsec, "Time in ns to complete a request in hardware. Default: 10,000ns");
+
+static int g_hw_queue_depth = 64;
+module_param_named(hw_queue_depth, g_hw_queue_depth, int, S_IRUGO);
+MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: 64");
+
+static bool g_use_per_node_hctx;
+module_param_named(use_per_node_hctx, g_use_per_node_hctx, bool, S_IRUGO);
+MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false");
+
+static struct nullb_device *null_alloc_dev(void);
+static void null_free_dev(struct nullb_device *dev);
+static void null_del_dev(struct nullb *nullb);
+static int null_add_dev(struct nullb_device *dev);
+static void null_free_device_storage(struct nullb_device *dev, bool is_cache);
+
+static inline struct nullb_device *to_nullb_device(struct config_item *item)
+{
+ return item ? container_of(item, struct nullb_device, item) : NULL;
+}
+
+static inline ssize_t nullb_device_uint_attr_show(unsigned int val, char *page)
+{
+ return snprintf(page, PAGE_SIZE, "%u\n", val);
+}
+
+static inline ssize_t nullb_device_ulong_attr_show(unsigned long val,
+ char *page)
+{
+ return snprintf(page, PAGE_SIZE, "%lu\n", val);
+}
+
+static inline ssize_t nullb_device_bool_attr_show(bool val, char *page)
+{
+ return snprintf(page, PAGE_SIZE, "%u\n", val);
+}
+
+static ssize_t nullb_device_uint_attr_store(unsigned int *val,
+ const char *page, size_t count)
+{
+ unsigned int tmp;
+ int result;
+
+ result = kstrtouint(page, 0, &tmp);
+ if (result)
+ return result;
+
+ *val = tmp;
+ return count;
+}
+
+static ssize_t nullb_device_ulong_attr_store(unsigned long *val,
+ const char *page, size_t count)
+{
+ int result;
+ unsigned long tmp;
+
+ result = kstrtoul(page, 0, &tmp);
+ if (result)
+ return result;
+
+ *val = tmp;
+ return count;
+}
+
+static ssize_t nullb_device_bool_attr_store(bool *val, const char *page,
+ size_t count)
+{
+ bool tmp;
+ int result;
+
+ result = kstrtobool(page, &tmp);
+ if (result)
+ return result;
+
+ *val = tmp;
+ return count;
+}
+
+/* The following macro should only be used with TYPE = {uint, ulong, bool}. */
+#define NULLB_DEVICE_ATTR(NAME, TYPE) \
+static ssize_t \
+nullb_device_##NAME##_show(struct config_item *item, char *page) \
+{ \
+ return nullb_device_##TYPE##_attr_show( \
+ to_nullb_device(item)->NAME, page); \
+} \
+static ssize_t \
+nullb_device_##NAME##_store(struct config_item *item, const char *page, \
+ size_t count) \
+{ \
+ if (test_bit(NULLB_DEV_FL_CONFIGURED, &to_nullb_device(item)->flags)) \
+ return -EBUSY; \
+ return nullb_device_##TYPE##_attr_store( \
+ &to_nullb_device(item)->NAME, page, count); \
+} \
+CONFIGFS_ATTR(nullb_device_, NAME);
+
+NULLB_DEVICE_ATTR(size, ulong);
+NULLB_DEVICE_ATTR(completion_nsec, ulong);
+NULLB_DEVICE_ATTR(submit_queues, uint);
+NULLB_DEVICE_ATTR(home_node, uint);
+NULLB_DEVICE_ATTR(queue_mode, uint);
+NULLB_DEVICE_ATTR(blocksize, uint);
+NULLB_DEVICE_ATTR(irqmode, uint);
+NULLB_DEVICE_ATTR(hw_queue_depth, uint);
+NULLB_DEVICE_ATTR(index, uint);
+NULLB_DEVICE_ATTR(use_lightnvm, bool);
+NULLB_DEVICE_ATTR(blocking, bool);
+NULLB_DEVICE_ATTR(use_per_node_hctx, bool);
+NULLB_DEVICE_ATTR(memory_backed, bool);
+NULLB_DEVICE_ATTR(discard, bool);
+NULLB_DEVICE_ATTR(mbps, uint);
+NULLB_DEVICE_ATTR(cache_size, ulong);
+
+static ssize_t nullb_device_power_show(struct config_item *item, char *page)
+{
+ return nullb_device_bool_attr_show(to_nullb_device(item)->power, page);
+}
+
+static ssize_t nullb_device_power_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ struct nullb_device *dev = to_nullb_device(item);
+ bool newp = false;
+ ssize_t ret;
+
+ ret = nullb_device_bool_attr_store(&newp, page, count);
+ if (ret < 0)
+ return ret;
+
+ if (!dev->power && newp) {
+ if (test_and_set_bit(NULLB_DEV_FL_UP, &dev->flags))
+ return count;
+ if (null_add_dev(dev)) {
+ clear_bit(NULLB_DEV_FL_UP, &dev->flags);
+ return -ENOMEM;
+ }
+
+ set_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags);
+ dev->power = newp;
+ } else if (dev->power && !newp) {
+ mutex_lock(&lock);
+ dev->power = newp;
+ null_del_dev(dev->nullb);
+ mutex_unlock(&lock);
+ clear_bit(NULLB_DEV_FL_UP, &dev->flags);
+ }
+
+ return count;
+}
+
+CONFIGFS_ATTR(nullb_device_, power);
+
+static ssize_t nullb_device_badblocks_show(struct config_item *item, char *page)
+{
+ struct nullb_device *t_dev = to_nullb_device(item);
+
+ return badblocks_show(&t_dev->badblocks, page, 0);
+}
+
+static ssize_t nullb_device_badblocks_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ struct nullb_device *t_dev = to_nullb_device(item);
+ char *orig, *buf, *tmp;
+ u64 start, end;
+ int ret;
+
+ orig = kstrndup(page, count, GFP_KERNEL);
+ if (!orig)
+ return -ENOMEM;
+
+ buf = strstrip(orig);
+
+ ret = -EINVAL;
+ if (buf[0] != '+' && buf[0] != '-')
+ goto out;
+ tmp = strchr(&buf[1], '-');
+ if (!tmp)
+ goto out;
+ *tmp = '\0';
+ ret = kstrtoull(buf + 1, 0, &start);
+ if (ret)
+ goto out;
+ ret = kstrtoull(tmp + 1, 0, &end);
+ if (ret)
+ goto out;
+ ret = -EINVAL;
+ if (start > end)
+ goto out;
+ /* enable badblocks */
+ cmpxchg(&t_dev->badblocks.shift, -1, 0);
+ if (buf[0] == '+')
+ ret = badblocks_set(&t_dev->badblocks, start,
+ end - start + 1, 1);
+ else
+ ret = badblocks_clear(&t_dev->badblocks, start,
+ end - start + 1);
+ if (ret == 0)
+ ret = count;
+out:
+ kfree(orig);
+ return ret;
+}
+CONFIGFS_ATTR(nullb_device_, badblocks);
+
+static struct configfs_attribute *nullb_device_attrs[] = {
+ &nullb_device_attr_size,
+ &nullb_device_attr_completion_nsec,
+ &nullb_device_attr_submit_queues,
+ &nullb_device_attr_home_node,
+ &nullb_device_attr_queue_mode,
+ &nullb_device_attr_blocksize,
+ &nullb_device_attr_irqmode,
+ &nullb_device_attr_hw_queue_depth,
+ &nullb_device_attr_index,
+ &nullb_device_attr_use_lightnvm,
+ &nullb_device_attr_blocking,
+ &nullb_device_attr_use_per_node_hctx,
+ &nullb_device_attr_power,
+ &nullb_device_attr_memory_backed,
+ &nullb_device_attr_discard,
+ &nullb_device_attr_mbps,
+ &nullb_device_attr_cache_size,
+ &nullb_device_attr_badblocks,
+ NULL,
+};
+
+static void nullb_device_release(struct config_item *item)
+{
+ struct nullb_device *dev = to_nullb_device(item);
+
+ null_free_device_storage(dev, false);
+ null_free_dev(dev);
+}
+
+static struct configfs_item_operations nullb_device_ops = {
+ .release = nullb_device_release,
+};
+
+static struct config_item_type nullb_device_type = {
+ .ct_item_ops = &nullb_device_ops,
+ .ct_attrs = nullb_device_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct
+config_item *nullb_group_make_item(struct config_group *group, const char *name)
+{
+ struct nullb_device *dev;
+
+ dev = null_alloc_dev();
+ if (!dev)
+ return ERR_PTR(-ENOMEM);
+
+ config_item_init_type_name(&dev->item, name, &nullb_device_type);
+
+ return &dev->item;
+}
+
+static void
+nullb_group_drop_item(struct config_group *group, struct config_item *item)
+{
+ struct nullb_device *dev = to_nullb_device(item);
+
+ if (test_and_clear_bit(NULLB_DEV_FL_UP, &dev->flags)) {
+ mutex_lock(&lock);
+ dev->power = false;
+ null_del_dev(dev->nullb);
+ mutex_unlock(&lock);
+ }
+
+ config_item_put(item);
+}
+
+static ssize_t memb_group_features_show(struct config_item *item, char *page)
+{
+ return snprintf(page, PAGE_SIZE, "memory_backed,discard,bandwidth,cache,badblocks\n");
+}
+
+CONFIGFS_ATTR_RO(memb_group_, features);
+
+static struct configfs_attribute *nullb_group_attrs[] = {
+ &memb_group_attr_features,
+ NULL,
+};
+
+static struct configfs_group_operations nullb_group_ops = {
+ .make_item = nullb_group_make_item,
+ .drop_item = nullb_group_drop_item,
+};
+
+static struct config_item_type nullb_group_type = {
+ .ct_group_ops = &nullb_group_ops,
+ .ct_attrs = nullb_group_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct configfs_subsystem nullb_subsys = {
+ .su_group = {
+ .cg_item = {
+ .ci_namebuf = "nullb",
+ .ci_type = &nullb_group_type,
+ },
+ },
+};
+
+static inline int null_cache_active(struct nullb *nullb)
+{
+ return test_bit(NULLB_DEV_FL_CACHE, &nullb->dev->flags);
+}
+
+static struct nullb_device *null_alloc_dev(void)
+{
+ struct nullb_device *dev;
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return NULL;
+ INIT_RADIX_TREE(&dev->data, GFP_ATOMIC);
+ INIT_RADIX_TREE(&dev->cache, GFP_ATOMIC);
+ if (badblocks_init(&dev->badblocks, 0)) {
+ kfree(dev);
+ return NULL;
+ }
+
+ dev->size = g_gb * 1024;
+ dev->completion_nsec = g_completion_nsec;
+ dev->submit_queues = g_submit_queues;
+ dev->home_node = g_home_node;
+ dev->queue_mode = g_queue_mode;
+ dev->blocksize = g_bs;
+ dev->irqmode = g_irqmode;
+ dev->hw_queue_depth = g_hw_queue_depth;
+ dev->use_lightnvm = g_use_lightnvm;
+ dev->blocking = g_blocking;
+ dev->use_per_node_hctx = g_use_per_node_hctx;
+ return dev;
+}
+
+static void null_free_dev(struct nullb_device *dev)
+{
+ if (!dev)
+ return;
+
+ badblocks_exit(&dev->badblocks);
+ kfree(dev);
+}
+
+static void put_tag(struct nullb_queue *nq, unsigned int tag)
+{
+ clear_bit_unlock(tag, nq->tag_map);
+
+ if (waitqueue_active(&nq->wait))
+ wake_up(&nq->wait);
+}
+
+static unsigned int get_tag(struct nullb_queue *nq)
+{
+ unsigned int tag;
+
+ do {
+ tag = find_first_zero_bit(nq->tag_map, nq->queue_depth);
+ if (tag >= nq->queue_depth)
+ return -1U;
+ } while (test_and_set_bit_lock(tag, nq->tag_map));
+
+ return tag;
+}
+
+static void free_cmd(struct nullb_cmd *cmd)
+{
+ put_tag(cmd->nq, cmd->tag);
+}
+
+static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer);
+
+static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq)
+{
+ struct nullb_cmd *cmd;
+ unsigned int tag;
+
+ tag = get_tag(nq);
+ if (tag != -1U) {
+ cmd = &nq->cmds[tag];
+ cmd->tag = tag;
+ cmd->error = BLK_STS_OK;
+ cmd->nq = nq;
+ if (nq->dev->irqmode == NULL_IRQ_TIMER) {
+ hrtimer_init(&cmd->timer, CLOCK_MONOTONIC,
+ HRTIMER_MODE_REL);
+ cmd->timer.function = null_cmd_timer_expired;
+ }
+ return cmd;
+ }
+
+ return NULL;
+}
+
+static struct nullb_cmd *alloc_cmd(struct nullb_queue *nq, int can_wait)
+{
+ struct nullb_cmd *cmd;
+ DEFINE_WAIT(wait);
+
+ cmd = __alloc_cmd(nq);
+ if (cmd || !can_wait)
+ return cmd;
+
+ do {
+ prepare_to_wait(&nq->wait, &wait, TASK_UNINTERRUPTIBLE);
+ cmd = __alloc_cmd(nq);
+ if (cmd)
+ break;
+
+ io_schedule();
+ } while (1);
+
+ finish_wait(&nq->wait, &wait);
+ return cmd;
+}
+
+static void end_cmd(struct nullb_cmd *cmd)
+{
+ struct request_queue *q = NULL;
+ int queue_mode = cmd->nq->dev->queue_mode;
+
+ if (cmd->rq)
+ q = cmd->rq->q;
+
+ switch (queue_mode) {
+ case NULL_Q_MQ:
+ blk_mq_end_request(cmd->rq, cmd->error);
+ return;
+ case NULL_Q_RQ:
+ INIT_LIST_HEAD(&cmd->rq->queuelist);
+ blk_end_request_all(cmd->rq, cmd->error);
+ break;
+ case NULL_Q_BIO:
+ cmd->bio->bi_status = cmd->error;
+ bio_endio(cmd->bio);
+ break;
+ }
+
+ free_cmd(cmd);
+
+ /* Restart queue if needed, as we are freeing a tag */
+ if (queue_mode == NULL_Q_RQ && blk_queue_stopped(q)) {
+ unsigned long flags;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ blk_start_queue_async(q);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+ }
+}
+
+static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer)
+{
+ end_cmd(container_of(timer, struct nullb_cmd, timer));
+
+ return HRTIMER_NORESTART;
+}
+
+static void null_cmd_end_timer(struct nullb_cmd *cmd)
+{
+ ktime_t kt = cmd->nq->dev->completion_nsec;
+
+ hrtimer_start(&cmd->timer, kt, HRTIMER_MODE_REL);
+}
+
+static void null_softirq_done_fn(struct request *rq)
+{
+ struct nullb *nullb = rq->q->queuedata;
+
+ if (nullb->dev->queue_mode == NULL_Q_MQ)
+ end_cmd(blk_mq_rq_to_pdu(rq));
+ else
+ end_cmd(rq->special);
+}
+
+static struct nullb_page *null_alloc_page(gfp_t gfp_flags)
+{
+ struct nullb_page *t_page;
+
+ t_page = kmalloc(sizeof(struct nullb_page), gfp_flags);
+ if (!t_page)
+ goto out;
+
+ t_page->page = alloc_pages(gfp_flags, 0);
+ if (!t_page->page)
+ goto out_freepage;
+
+ memset(t_page->bitmap, 0, sizeof(t_page->bitmap));
+ return t_page;
+out_freepage:
+ kfree(t_page);
+out:
+ return NULL;
+}
+
+static void null_free_page(struct nullb_page *t_page)
+{
+ __set_bit(NULLB_PAGE_FREE, t_page->bitmap);
+ if (test_bit(NULLB_PAGE_LOCK, t_page->bitmap))
+ return;
+ __free_page(t_page->page);
+ kfree(t_page);
+}
+
+static bool null_page_empty(struct nullb_page *page)
+{
+ int size = MAP_SZ - 2;
+
+ return find_first_bit(page->bitmap, size) == size;
+}
+
+static void null_free_sector(struct nullb *nullb, sector_t sector,
+ bool is_cache)
+{
+ unsigned int sector_bit;
+ u64 idx;
+ struct nullb_page *t_page, *ret;
+ struct radix_tree_root *root;
+
+ root = is_cache ? &nullb->dev->cache : &nullb->dev->data;
+ idx = sector >> PAGE_SECTORS_SHIFT;
+ sector_bit = (sector & SECTOR_MASK);
+
+ t_page = radix_tree_lookup(root, idx);
+ if (t_page) {
+ __clear_bit(sector_bit, t_page->bitmap);
+
+ if (null_page_empty(t_page)) {
+ ret = radix_tree_delete_item(root, idx, t_page);
+ WARN_ON(ret != t_page);
+ null_free_page(ret);
+ if (is_cache)
+ nullb->dev->curr_cache -= PAGE_SIZE;
+ }
+ }
+}
+
+static struct nullb_page *null_radix_tree_insert(struct nullb *nullb, u64 idx,
+ struct nullb_page *t_page, bool is_cache)
+{
+ struct radix_tree_root *root;
+
+ root = is_cache ? &nullb->dev->cache : &nullb->dev->data;
+
+ if (radix_tree_insert(root, idx, t_page)) {
+ null_free_page(t_page);
+ t_page = radix_tree_lookup(root, idx);
+ WARN_ON(!t_page || t_page->page->index != idx);
+ } else if (is_cache)
+ nullb->dev->curr_cache += PAGE_SIZE;
+
+ return t_page;
+}
+
+static void null_free_device_storage(struct nullb_device *dev, bool is_cache)
+{
+ unsigned long pos = 0;
+ int nr_pages;
+ struct nullb_page *ret, *t_pages[FREE_BATCH];
+ struct radix_tree_root *root;
+
+ root = is_cache ? &dev->cache : &dev->data;
+
+ do {
+ int i;
+
+ nr_pages = radix_tree_gang_lookup(root,
+ (void **)t_pages, pos, FREE_BATCH);
+
+ for (i = 0; i < nr_pages; i++) {
+ pos = t_pages[i]->page->index;
+ ret = radix_tree_delete_item(root, pos, t_pages[i]);
+ WARN_ON(ret != t_pages[i]);
+ null_free_page(ret);
+ }
+
+ pos++;
+ } while (nr_pages == FREE_BATCH);
+
+ if (is_cache)
+ dev->curr_cache = 0;
+}
+
+static struct nullb_page *__null_lookup_page(struct nullb *nullb,
+ sector_t sector, bool for_write, bool is_cache)
+{
+ unsigned int sector_bit;
+ u64 idx;
+ struct nullb_page *t_page;
+ struct radix_tree_root *root;
+
+ idx = sector >> PAGE_SECTORS_SHIFT;
+ sector_bit = (sector & SECTOR_MASK);
+
+ root = is_cache ? &nullb->dev->cache : &nullb->dev->data;
+ t_page = radix_tree_lookup(root, idx);
+ WARN_ON(t_page && t_page->page->index != idx);
+
+ if (t_page && (for_write || test_bit(sector_bit, t_page->bitmap)))
+ return t_page;
+
+ return NULL;
+}
+
+static struct nullb_page *null_lookup_page(struct nullb *nullb,
+ sector_t sector, bool for_write, bool ignore_cache)
+{
+ struct nullb_page *page = NULL;
+
+ if (!ignore_cache)
+ page = __null_lookup_page(nullb, sector, for_write, true);
+ if (page)
+ return page;
+ return __null_lookup_page(nullb, sector, for_write, false);
+}
+
+static struct nullb_page *null_insert_page(struct nullb *nullb,
+ sector_t sector, bool ignore_cache)
+{
+ u64 idx;
+ struct nullb_page *t_page;
+
+ t_page = null_lookup_page(nullb, sector, true, ignore_cache);
+ if (t_page)
+ return t_page;
+
+ spin_unlock_irq(&nullb->lock);
+
+ t_page = null_alloc_page(GFP_NOIO);
+ if (!t_page)
+ goto out_lock;
+
+ if (radix_tree_preload(GFP_NOIO))
+ goto out_freepage;
+
+ spin_lock_irq(&nullb->lock);
+ idx = sector >> PAGE_SECTORS_SHIFT;
+ t_page->page->index = idx;
+ t_page = null_radix_tree_insert(nullb, idx, t_page, !ignore_cache);
+ radix_tree_preload_end();
+
+ return t_page;
+out_freepage:
+ null_free_page(t_page);
+out_lock:
+ spin_lock_irq(&nullb->lock);
+ return null_lookup_page(nullb, sector, true, ignore_cache);
+}
+
+static int null_flush_cache_page(struct nullb *nullb, struct nullb_page *c_page)
+{
+ int i;
+ unsigned int offset;
+ u64 idx;
+ struct nullb_page *t_page, *ret;
+ void *dst, *src;
+
+ idx = c_page->page->index;
+
+ t_page = null_insert_page(nullb, idx << PAGE_SECTORS_SHIFT, true);
+
+ __clear_bit(NULLB_PAGE_LOCK, c_page->bitmap);
+ if (test_bit(NULLB_PAGE_FREE, c_page->bitmap)) {
+ null_free_page(c_page);
+ if (t_page && null_page_empty(t_page)) {
+ ret = radix_tree_delete_item(&nullb->dev->data,
+ idx, t_page);
+ null_free_page(t_page);
+ }
+ return 0;
+ }
+
+ if (!t_page)
+ return -ENOMEM;
+
+ src = kmap_atomic(c_page->page);
+ dst = kmap_atomic(t_page->page);
+
+ for (i = 0; i < PAGE_SECTORS;
+ i += (nullb->dev->blocksize >> SECTOR_SHIFT)) {
+ if (test_bit(i, c_page->bitmap)) {
+ offset = (i << SECTOR_SHIFT);
+ memcpy(dst + offset, src + offset,
+ nullb->dev->blocksize);
+ __set_bit(i, t_page->bitmap);
+ }
+ }
+
+ kunmap_atomic(dst);
+ kunmap_atomic(src);
+
+ ret = radix_tree_delete_item(&nullb->dev->cache, idx, c_page);
+ null_free_page(ret);
+ nullb->dev->curr_cache -= PAGE_SIZE;
+
+ return 0;
+}
+
+static int null_make_cache_space(struct nullb *nullb, unsigned long n)
+{
+ int i, err, nr_pages;
+ struct nullb_page *c_pages[FREE_BATCH];
+ unsigned long flushed = 0, one_round;
+
+again:
+ if ((nullb->dev->cache_size * 1024 * 1024) >
+ nullb->dev->curr_cache + n || nullb->dev->curr_cache == 0)
+ return 0;
+
+ nr_pages = radix_tree_gang_lookup(&nullb->dev->cache,
+ (void **)c_pages, nullb->cache_flush_pos, FREE_BATCH);
+ /*
+ * nullb_flush_cache_page could unlock before using the c_pages. To
+ * avoid race, we don't allow page free
+ */
+ for (i = 0; i < nr_pages; i++) {
+ nullb->cache_flush_pos = c_pages[i]->page->index;
+ /*
+ * We found the page which is being flushed to disk by other
+ * threads
+ */
+ if (test_bit(NULLB_PAGE_LOCK, c_pages[i]->bitmap))
+ c_pages[i] = NULL;
+ else
+ __set_bit(NULLB_PAGE_LOCK, c_pages[i]->bitmap);
+ }
+
+ one_round = 0;
+ for (i = 0; i < nr_pages; i++) {
+ if (c_pages[i] == NULL)
+ continue;
+ err = null_flush_cache_page(nullb, c_pages[i]);
+ if (err)
+ return err;
+ one_round++;
+ }
+ flushed += one_round << PAGE_SHIFT;
+
+ if (n > flushed) {
+ if (nr_pages == 0)
+ nullb->cache_flush_pos = 0;
+ if (one_round == 0) {
+ /* give other threads a chance */
+ spin_unlock_irq(&nullb->lock);
+ spin_lock_irq(&nullb->lock);
+ }
+ goto again;
+ }
+ return 0;
+}
+
+static int copy_to_nullb(struct nullb *nullb, struct page *source,
+ unsigned int off, sector_t sector, size_t n, bool is_fua)
+{
+ size_t temp, count = 0;
+ unsigned int offset;
+ struct nullb_page *t_page;
+ void *dst, *src;
+
+ while (count < n) {
+ temp = min_t(size_t, nullb->dev->blocksize, n - count);
+
+ if (null_cache_active(nullb) && !is_fua)
+ null_make_cache_space(nullb, PAGE_SIZE);
+
+ offset = (sector & SECTOR_MASK) << SECTOR_SHIFT;
+ t_page = null_insert_page(nullb, sector,
+ !null_cache_active(nullb) || is_fua);
+ if (!t_page)
+ return -ENOSPC;
+
+ src = kmap_atomic(source);
+ dst = kmap_atomic(t_page->page);
+ memcpy(dst + offset, src + off + count, temp);
+ kunmap_atomic(dst);
+ kunmap_atomic(src);
+
+ __set_bit(sector & SECTOR_MASK, t_page->bitmap);
+
+ if (is_fua)
+ null_free_sector(nullb, sector, true);
+
+ count += temp;
+ sector += temp >> SECTOR_SHIFT;
+ }
+ return 0;
+}
+
+static int copy_from_nullb(struct nullb *nullb, struct page *dest,
+ unsigned int off, sector_t sector, size_t n)
+{
+ size_t temp, count = 0;
+ unsigned int offset;
+ struct nullb_page *t_page;
+ void *dst, *src;
+
+ while (count < n) {
+ temp = min_t(size_t, nullb->dev->blocksize, n - count);
+
+ offset = (sector & SECTOR_MASK) << SECTOR_SHIFT;
+ t_page = null_lookup_page(nullb, sector, false,
+ !null_cache_active(nullb));
+
+ dst = kmap_atomic(dest);
+ if (!t_page) {
+ memset(dst + off + count, 0, temp);
+ goto next;
+ }
+ src = kmap_atomic(t_page->page);
+ memcpy(dst + off + count, src + offset, temp);
+ kunmap_atomic(src);
+next:
+ kunmap_atomic(dst);
+
+ count += temp;
+ sector += temp >> SECTOR_SHIFT;
+ }
+ return 0;
+}
+
+static void null_handle_discard(struct nullb *nullb, sector_t sector, size_t n)
+{
+ size_t temp;
+
+ spin_lock_irq(&nullb->lock);
+ while (n > 0) {
+ temp = min_t(size_t, n, nullb->dev->blocksize);
+ null_free_sector(nullb, sector, false);
+ if (null_cache_active(nullb))
+ null_free_sector(nullb, sector, true);
+ sector += temp >> SECTOR_SHIFT;
+ n -= temp;
+ }
+ spin_unlock_irq(&nullb->lock);
+}
+
+static int null_handle_flush(struct nullb *nullb)
+{
+ int err;
+
+ if (!null_cache_active(nullb))
+ return 0;
+
+ spin_lock_irq(&nullb->lock);
+ while (true) {
+ err = null_make_cache_space(nullb,
+ nullb->dev->cache_size * 1024 * 1024);
+ if (err || nullb->dev->curr_cache == 0)
+ break;
+ }
+
+ WARN_ON(!radix_tree_empty(&nullb->dev->cache));
+ spin_unlock_irq(&nullb->lock);
+ return err;
+}
+
+static int null_transfer(struct nullb *nullb, struct page *page,
+ unsigned int len, unsigned int off, bool is_write, sector_t sector,
+ bool is_fua)
+{
+ int err = 0;
+
+ if (!is_write) {
+ err = copy_from_nullb(nullb, page, off, sector, len);
+ flush_dcache_page(page);
+ } else {
+ flush_dcache_page(page);
+ err = copy_to_nullb(nullb, page, off, sector, len, is_fua);
+ }
+
+ return err;
+}
+
+static int null_handle_rq(struct nullb_cmd *cmd)
+{
+ struct request *rq = cmd->rq;
+ struct nullb *nullb = cmd->nq->dev->nullb;
+ int err;
+ unsigned int len;
+ sector_t sector;
+ struct req_iterator iter;
+ struct bio_vec bvec;
+
+ sector = blk_rq_pos(rq);
+
+ if (req_op(rq) == REQ_OP_DISCARD) {
+ null_handle_discard(nullb, sector, blk_rq_bytes(rq));
+ return 0;
+ }
+
+ spin_lock_irq(&nullb->lock);
+ rq_for_each_segment(bvec, rq, iter) {
+ len = bvec.bv_len;
+ err = null_transfer(nullb, bvec.bv_page, len, bvec.bv_offset,
+ op_is_write(req_op(rq)), sector,
+ rq->cmd_flags & REQ_FUA);
+ if (err) {
+ spin_unlock_irq(&nullb->lock);
+ return err;
+ }
+ sector += len >> SECTOR_SHIFT;
+ }
+ spin_unlock_irq(&nullb->lock);
+
+ return 0;
+}
+
+static int null_handle_bio(struct nullb_cmd *cmd)
+{
+ struct bio *bio = cmd->bio;
+ struct nullb *nullb = cmd->nq->dev->nullb;
+ int err;
+ unsigned int len;
+ sector_t sector;
+ struct bio_vec bvec;
+ struct bvec_iter iter;
+
+ sector = bio->bi_iter.bi_sector;
+
+ if (bio_op(bio) == REQ_OP_DISCARD) {
+ null_handle_discard(nullb, sector,
+ bio_sectors(bio) << SECTOR_SHIFT);
+ return 0;
+ }
+
+ spin_lock_irq(&nullb->lock);
+ bio_for_each_segment(bvec, bio, iter) {
+ len = bvec.bv_len;
+ err = null_transfer(nullb, bvec.bv_page, len, bvec.bv_offset,
+ op_is_write(bio_op(bio)), sector,
+ bio_op(bio) & REQ_FUA);
+ if (err) {
+ spin_unlock_irq(&nullb->lock);
+ return err;
+ }
+ sector += len >> SECTOR_SHIFT;
+ }
+ spin_unlock_irq(&nullb->lock);
+ return 0;
+}
+
+static void null_stop_queue(struct nullb *nullb)
+{
+ struct request_queue *q = nullb->q;
+
+ if (nullb->dev->queue_mode == NULL_Q_MQ)
+ blk_mq_stop_hw_queues(q);
+ else {
+ spin_lock_irq(q->queue_lock);
+ blk_stop_queue(q);
+ spin_unlock_irq(q->queue_lock);
+ }
+}
+
+static void null_restart_queue_async(struct nullb *nullb)
+{
+ struct request_queue *q = nullb->q;
+ unsigned long flags;
+
+ if (nullb->dev->queue_mode == NULL_Q_MQ)
+ blk_mq_start_stopped_hw_queues(q, true);
+ else {
+ spin_lock_irqsave(q->queue_lock, flags);
+ blk_start_queue_async(q);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+ }
+}
+
+static blk_status_t null_handle_cmd(struct nullb_cmd *cmd)
+{
+ struct nullb_device *dev = cmd->nq->dev;
+ struct nullb *nullb = dev->nullb;
+ int err = 0;
+
+ if (test_bit(NULLB_DEV_FL_THROTTLED, &dev->flags)) {
+ struct request *rq = cmd->rq;
+
+ if (!hrtimer_active(&nullb->bw_timer))
+ hrtimer_restart(&nullb->bw_timer);
+
+ if (atomic_long_sub_return(blk_rq_bytes(rq),
+ &nullb->cur_bytes) < 0) {
+ null_stop_queue(nullb);
+ /* race with timer */
+ if (atomic_long_read(&nullb->cur_bytes) > 0)
+ null_restart_queue_async(nullb);
+ if (dev->queue_mode == NULL_Q_RQ) {
+ struct request_queue *q = nullb->q;
+
+ spin_lock_irq(q->queue_lock);
+ rq->rq_flags |= RQF_DONTPREP;
+ blk_requeue_request(q, rq);
+ spin_unlock_irq(q->queue_lock);
+ return BLK_STS_OK;
+ } else
+ /* requeue request */
+ return BLK_STS_RESOURCE;
+ }
+ }
+
+ if (nullb->dev->badblocks.shift != -1) {
+ int bad_sectors;
+ sector_t sector, size, first_bad;
+ bool is_flush = true;
+
+ if (dev->queue_mode == NULL_Q_BIO &&
+ bio_op(cmd->bio) != REQ_OP_FLUSH) {
+ is_flush = false;
+ sector = cmd->bio->bi_iter.bi_sector;
+ size = bio_sectors(cmd->bio);
+ }
+ if (dev->queue_mode != NULL_Q_BIO &&
+ req_op(cmd->rq) != REQ_OP_FLUSH) {
+ is_flush = false;
+ sector = blk_rq_pos(cmd->rq);
+ size = blk_rq_sectors(cmd->rq);
+ }
+ if (!is_flush && badblocks_check(&nullb->dev->badblocks, sector,
+ size, &first_bad, &bad_sectors)) {
+ cmd->error = BLK_STS_IOERR;
+ goto out;
+ }
+ }
+
+ if (dev->memory_backed) {
+ if (dev->queue_mode == NULL_Q_BIO) {
+ if (bio_op(cmd->bio) == REQ_OP_FLUSH)
+ err = null_handle_flush(nullb);
+ else
+ err = null_handle_bio(cmd);
+ } else {
+ if (req_op(cmd->rq) == REQ_OP_FLUSH)
+ err = null_handle_flush(nullb);
+ else
+ err = null_handle_rq(cmd);
+ }
+ }
+ cmd->error = errno_to_blk_status(err);
+out:
+ /* Complete IO by inline, softirq or timer */
+ switch (dev->irqmode) {
+ case NULL_IRQ_SOFTIRQ:
+ switch (dev->queue_mode) {
+ case NULL_Q_MQ:
+ blk_mq_complete_request(cmd->rq);
+ break;
+ case NULL_Q_RQ:
+ blk_complete_request(cmd->rq);
+ break;
+ case NULL_Q_BIO:
+ /*
+ * XXX: no proper submitting cpu information available.
+ */
+ end_cmd(cmd);
+ break;
+ }
+ break;
+ case NULL_IRQ_NONE:
+ end_cmd(cmd);
+ break;
+ case NULL_IRQ_TIMER:
+ null_cmd_end_timer(cmd);
+ break;
+ }
+ return BLK_STS_OK;
+}
+
+static enum hrtimer_restart nullb_bwtimer_fn(struct hrtimer *timer)
+{
+ struct nullb *nullb = container_of(timer, struct nullb, bw_timer);
+ ktime_t timer_interval = ktime_set(0, TIMER_INTERVAL);
+ unsigned int mbps = nullb->dev->mbps;
+
+ if (atomic_long_read(&nullb->cur_bytes) == mb_per_tick(mbps))
+ return HRTIMER_NORESTART;
+
+ atomic_long_set(&nullb->cur_bytes, mb_per_tick(mbps));
+ null_restart_queue_async(nullb);
+
+ hrtimer_forward_now(&nullb->bw_timer, timer_interval);
+
+ return HRTIMER_RESTART;
+}
+
+static void nullb_setup_bwtimer(struct nullb *nullb)
+{
+ ktime_t timer_interval = ktime_set(0, TIMER_INTERVAL);
+
+ hrtimer_init(&nullb->bw_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ nullb->bw_timer.function = nullb_bwtimer_fn;
+ atomic_long_set(&nullb->cur_bytes, mb_per_tick(nullb->dev->mbps));
+ hrtimer_start(&nullb->bw_timer, timer_interval, HRTIMER_MODE_REL);
+}
+
+static struct nullb_queue *nullb_to_queue(struct nullb *nullb)
+{
+ int index = 0;
+
+ if (nullb->nr_queues != 1)
+ index = raw_smp_processor_id() / ((nr_cpu_ids + nullb->nr_queues - 1) / nullb->nr_queues);
+
+ return &nullb->queues[index];
+}
+
+static blk_qc_t null_queue_bio(struct request_queue *q, struct bio *bio)
+{
+ struct nullb *nullb = q->queuedata;
+ struct nullb_queue *nq = nullb_to_queue(nullb);
+ struct nullb_cmd *cmd;
+
+ cmd = alloc_cmd(nq, 1);
+ cmd->bio = bio;
+
+ null_handle_cmd(cmd);
+ return BLK_QC_T_NONE;
+}
+
+static int null_rq_prep_fn(struct request_queue *q, struct request *req)
+{
+ struct nullb *nullb = q->queuedata;
+ struct nullb_queue *nq = nullb_to_queue(nullb);
+ struct nullb_cmd *cmd;
+
+ cmd = alloc_cmd(nq, 0);
+ if (cmd) {
+ cmd->rq = req;
+ req->special = cmd;
+ return BLKPREP_OK;
+ }
+ blk_stop_queue(q);
+
+ return BLKPREP_DEFER;
+}
+
+static void null_request_fn(struct request_queue *q)
+{
+ struct request *rq;
+
+ while ((rq = blk_fetch_request(q)) != NULL) {
+ struct nullb_cmd *cmd = rq->special;
+
+ spin_unlock_irq(q->queue_lock);
+ null_handle_cmd(cmd);
+ spin_lock_irq(q->queue_lock);
+ }
+}
+
+static blk_status_t null_queue_rq(struct blk_mq_hw_ctx *hctx,
+ const struct blk_mq_queue_data *bd)
+{
+ struct nullb_cmd *cmd = blk_mq_rq_to_pdu(bd->rq);
+ struct nullb_queue *nq = hctx->driver_data;
+
+ might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING);
+
+ if (nq->dev->irqmode == NULL_IRQ_TIMER) {
+ hrtimer_init(&cmd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ cmd->timer.function = null_cmd_timer_expired;
+ }
+ cmd->rq = bd->rq;
+ cmd->error = BLK_STS_OK;
+ cmd->nq = nq;
+
+ blk_mq_start_request(bd->rq);
+
+ return null_handle_cmd(cmd);
+}
+
+static const struct blk_mq_ops null_mq_ops = {
+ .queue_rq = null_queue_rq,
+ .complete = null_softirq_done_fn,
+};
+
+static void cleanup_queue(struct nullb_queue *nq)
+{
+ kfree(nq->tag_map);
+ kfree(nq->cmds);
+}
+
+static void cleanup_queues(struct nullb *nullb)
+{
+ int i;
+
+ for (i = 0; i < nullb->nr_queues; i++)
+ cleanup_queue(&nullb->queues[i]);
+
+ kfree(nullb->queues);
+}
+
+#ifdef CONFIG_NVM
+
+static void null_lnvm_end_io(struct request *rq, blk_status_t status)
+{
+ struct nvm_rq *rqd = rq->end_io_data;
+
+ /* XXX: lighnvm core seems to expect NVM_RSP_* values here.. */
+ rqd->error = status ? -EIO : 0;
+ nvm_end_io(rqd);
+
+ blk_put_request(rq);
+}
+
+static int null_lnvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
+{
+ struct request_queue *q = dev->q;
+ struct request *rq;
+ struct bio *bio = rqd->bio;
+
+ rq = blk_mq_alloc_request(q,
+ op_is_write(bio_op(bio)) ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
+ if (IS_ERR(rq))
+ return -ENOMEM;
+
+ blk_init_request_from_bio(rq, bio);
+
+ rq->end_io_data = rqd;
+
+ blk_execute_rq_nowait(q, NULL, rq, 0, null_lnvm_end_io);
+
+ return 0;
+}
+
+static int null_lnvm_id(struct nvm_dev *dev, struct nvm_id *id)
+{
+ struct nullb *nullb = dev->q->queuedata;
+ sector_t size = (sector_t)nullb->dev->size * 1024 * 1024ULL;
+ sector_t blksize;
+ struct nvm_id_group *grp;
+
+ id->ver_id = 0x1;
+ id->vmnt = 0;
+ id->cap = 0x2;
+ id->dom = 0x1;
+
+ id->ppaf.blk_offset = 0;
+ id->ppaf.blk_len = 16;
+ id->ppaf.pg_offset = 16;
+ id->ppaf.pg_len = 16;
+ id->ppaf.sect_offset = 32;
+ id->ppaf.sect_len = 8;
+ id->ppaf.pln_offset = 40;
+ id->ppaf.pln_len = 8;
+ id->ppaf.lun_offset = 48;
+ id->ppaf.lun_len = 8;
+ id->ppaf.ch_offset = 56;
+ id->ppaf.ch_len = 8;
+
+ sector_div(size, nullb->dev->blocksize); /* convert size to pages */
+ size >>= 8; /* concert size to pgs pr blk */
+ grp = &id->grp;
+ grp->mtype = 0;
+ grp->fmtype = 0;
+ grp->num_ch = 1;
+ grp->num_pg = 256;
+ blksize = size;
+ size >>= 16;
+ grp->num_lun = size + 1;
+ sector_div(blksize, grp->num_lun);
+ grp->num_blk = blksize;
+ grp->num_pln = 1;
+
+ grp->fpg_sz = nullb->dev->blocksize;
+ grp->csecs = nullb->dev->blocksize;
+ grp->trdt = 25000;
+ grp->trdm = 25000;
+ grp->tprt = 500000;
+ grp->tprm = 500000;
+ grp->tbet = 1500000;
+ grp->tbem = 1500000;
+ grp->mpos = 0x010101; /* single plane rwe */
+ grp->cpar = nullb->dev->hw_queue_depth;
+
+ return 0;
+}
+
+static void *null_lnvm_create_dma_pool(struct nvm_dev *dev, char *name)
+{
+ mempool_t *virtmem_pool;
+
+ virtmem_pool = mempool_create_slab_pool(64, ppa_cache);
+ if (!virtmem_pool) {
+ pr_err("null_blk: Unable to create virtual memory pool\n");
+ return NULL;
+ }
+
+ return virtmem_pool;
+}
+
+static void null_lnvm_destroy_dma_pool(void *pool)
+{
+ mempool_destroy(pool);
+}
+
+static void *null_lnvm_dev_dma_alloc(struct nvm_dev *dev, void *pool,
+ gfp_t mem_flags, dma_addr_t *dma_handler)
+{
+ return mempool_alloc(pool, mem_flags);
+}
+
+static void null_lnvm_dev_dma_free(void *pool, void *entry,
+ dma_addr_t dma_handler)
+{
+ mempool_free(entry, pool);
+}
+
+static struct nvm_dev_ops null_lnvm_dev_ops = {
+ .identity = null_lnvm_id,
+ .submit_io = null_lnvm_submit_io,
+
+ .create_dma_pool = null_lnvm_create_dma_pool,
+ .destroy_dma_pool = null_lnvm_destroy_dma_pool,
+ .dev_dma_alloc = null_lnvm_dev_dma_alloc,
+ .dev_dma_free = null_lnvm_dev_dma_free,
+
+ /* Simulate nvme protocol restriction */
+ .max_phys_sect = 64,
+};
+
+static int null_nvm_register(struct nullb *nullb)
+{
+ struct nvm_dev *dev;
+ int rv;
+
+ dev = nvm_alloc_dev(0);
+ if (!dev)
+ return -ENOMEM;
+
+ dev->q = nullb->q;
+ memcpy(dev->name, nullb->disk_name, DISK_NAME_LEN);
+ dev->ops = &null_lnvm_dev_ops;
+
+ rv = nvm_register(dev);
+ if (rv) {
+ kfree(dev);
+ return rv;
+ }
+ nullb->ndev = dev;
+ return 0;
+}
+
+static void null_nvm_unregister(struct nullb *nullb)
+{
+ nvm_unregister(nullb->ndev);
+}
+#else
+static int null_nvm_register(struct nullb *nullb)
+{
+ pr_err("null_blk: CONFIG_NVM needs to be enabled for LightNVM\n");
+ return -EINVAL;
+}
+static void null_nvm_unregister(struct nullb *nullb) {}
+#endif /* CONFIG_NVM */
+
+static void null_del_dev(struct nullb *nullb)
+{
+ struct nullb_device *dev;
+
+ if (!nullb)
+ return;
+
+ dev = nullb->dev;
+
+ ida_simple_remove(&nullb_indexes, nullb->index);
+
+ list_del_init(&nullb->list);
+
+ if (dev->use_lightnvm)
+ null_nvm_unregister(nullb);
+ else
+ del_gendisk(nullb->disk);
+
+ if (test_bit(NULLB_DEV_FL_THROTTLED, &nullb->dev->flags)) {
+ hrtimer_cancel(&nullb->bw_timer);
+ atomic_long_set(&nullb->cur_bytes, LONG_MAX);
+ null_restart_queue_async(nullb);
+ }
+
+ blk_cleanup_queue(nullb->q);
+ if (dev->queue_mode == NULL_Q_MQ &&
+ nullb->tag_set == &nullb->__tag_set)
+ blk_mq_free_tag_set(nullb->tag_set);
+ if (!dev->use_lightnvm)
+ put_disk(nullb->disk);
+ cleanup_queues(nullb);
+ if (null_cache_active(nullb))
+ null_free_device_storage(nullb->dev, true);
+ kfree(nullb);
+ dev->nullb = NULL;
+}
+
+static void null_config_discard(struct nullb *nullb)
+{
+ if (nullb->dev->discard == false)
+ return;
+ nullb->q->limits.discard_granularity = nullb->dev->blocksize;
+ nullb->q->limits.discard_alignment = nullb->dev->blocksize;
+ blk_queue_max_discard_sectors(nullb->q, UINT_MAX >> 9);
+ queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, nullb->q);
+}
+
+static int null_open(struct block_device *bdev, fmode_t mode)
+{
+ return 0;
+}
+
+static void null_release(struct gendisk *disk, fmode_t mode)
+{
+}
+
+static const struct block_device_operations null_fops = {
+ .owner = THIS_MODULE,
+ .open = null_open,
+ .release = null_release,
+};
+
+static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq)
+{
+ BUG_ON(!nullb);
+ BUG_ON(!nq);
+
+ init_waitqueue_head(&nq->wait);
+ nq->queue_depth = nullb->queue_depth;
+ nq->dev = nullb->dev;
+}
+
+static void null_init_queues(struct nullb *nullb)
+{
+ struct request_queue *q = nullb->q;
+ struct blk_mq_hw_ctx *hctx;
+ struct nullb_queue *nq;
+ int i;
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ if (!hctx->nr_ctx || !hctx->tags)
+ continue;
+ nq = &nullb->queues[i];
+ hctx->driver_data = nq;
+ null_init_queue(nullb, nq);
+ nullb->nr_queues++;
+ }
+}
+
+static int setup_commands(struct nullb_queue *nq)
+{
+ struct nullb_cmd *cmd;
+ int i, tag_size;
+
+ nq->cmds = kzalloc(nq->queue_depth * sizeof(*cmd), GFP_KERNEL);
+ if (!nq->cmds)
+ return -ENOMEM;
+
+ tag_size = ALIGN(nq->queue_depth, BITS_PER_LONG) / BITS_PER_LONG;
+ nq->tag_map = kzalloc(tag_size * sizeof(unsigned long), GFP_KERNEL);
+ if (!nq->tag_map) {
+ kfree(nq->cmds);
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < nq->queue_depth; i++) {
+ cmd = &nq->cmds[i];
+ INIT_LIST_HEAD(&cmd->list);
+ cmd->ll_list.next = NULL;
+ cmd->tag = -1U;
+ }
+
+ return 0;
+}
+
+static int setup_queues(struct nullb *nullb)
+{
+ nullb->queues = kzalloc(nullb->dev->submit_queues *
+ sizeof(struct nullb_queue), GFP_KERNEL);
+ if (!nullb->queues)
+ return -ENOMEM;
+
+ nullb->nr_queues = 0;
+ nullb->queue_depth = nullb->dev->hw_queue_depth;
+
+ return 0;
+}
+
+static int init_driver_queues(struct nullb *nullb)
+{
+ struct nullb_queue *nq;
+ int i, ret = 0;
+
+ for (i = 0; i < nullb->dev->submit_queues; i++) {
+ nq = &nullb->queues[i];
+
+ null_init_queue(nullb, nq);
+
+ ret = setup_commands(nq);
+ if (ret)
+ return ret;
+ nullb->nr_queues++;
+ }
+ return 0;
+}
+
+static int null_gendisk_register(struct nullb *nullb)
+{
+ struct gendisk *disk;
+ sector_t size;
+
+ disk = nullb->disk = alloc_disk_node(1, nullb->dev->home_node);
+ if (!disk)
+ return -ENOMEM;
+ size = (sector_t)nullb->dev->size * 1024 * 1024ULL;
+ set_capacity(disk, size >> 9);
+
+ disk->flags |= GENHD_FL_EXT_DEVT | GENHD_FL_SUPPRESS_PARTITION_INFO;
+ disk->major = null_major;
+ disk->first_minor = nullb->index;
+ disk->fops = &null_fops;
+ disk->private_data = nullb;
+ disk->queue = nullb->q;
+ strncpy(disk->disk_name, nullb->disk_name, DISK_NAME_LEN);
+
+ add_disk(disk);
+ return 0;
+}
+
+static int null_init_tag_set(struct nullb *nullb, struct blk_mq_tag_set *set)
+{
+ set->ops = &null_mq_ops;
+ set->nr_hw_queues = nullb ? nullb->dev->submit_queues :
+ g_submit_queues;
+ set->queue_depth = nullb ? nullb->dev->hw_queue_depth :
+ g_hw_queue_depth;
+ set->numa_node = nullb ? nullb->dev->home_node : g_home_node;
+ set->cmd_size = sizeof(struct nullb_cmd);
+ set->flags = BLK_MQ_F_SHOULD_MERGE;
+ set->driver_data = NULL;
+
+ if ((nullb && nullb->dev->blocking) || g_blocking)
+ set->flags |= BLK_MQ_F_BLOCKING;
+
+ return blk_mq_alloc_tag_set(set);
+}
+
+static void null_validate_conf(struct nullb_device *dev)
+{
+ dev->blocksize = round_down(dev->blocksize, 512);
+ dev->blocksize = clamp_t(unsigned int, dev->blocksize, 512, 4096);
+ if (dev->use_lightnvm && dev->blocksize != 4096)
+ dev->blocksize = 4096;
+
+ if (dev->use_lightnvm && dev->queue_mode != NULL_Q_MQ)
+ dev->queue_mode = NULL_Q_MQ;
+
+ if (dev->queue_mode == NULL_Q_MQ && dev->use_per_node_hctx) {
+ if (dev->submit_queues != nr_online_nodes)
+ dev->submit_queues = nr_online_nodes;
+ } else if (dev->submit_queues > nr_cpu_ids)
+ dev->submit_queues = nr_cpu_ids;
+ else if (dev->submit_queues == 0)
+ dev->submit_queues = 1;
+
+ dev->queue_mode = min_t(unsigned int, dev->queue_mode, NULL_Q_MQ);
+ dev->irqmode = min_t(unsigned int, dev->irqmode, NULL_IRQ_TIMER);
+
+ /* Do memory allocation, so set blocking */
+ if (dev->memory_backed)
+ dev->blocking = true;
+ else /* cache is meaningless */
+ dev->cache_size = 0;
+ dev->cache_size = min_t(unsigned long, ULONG_MAX / 1024 / 1024,
+ dev->cache_size);
+ dev->mbps = min_t(unsigned int, 1024 * 40, dev->mbps);
+ /* can not stop a queue */
+ if (dev->queue_mode == NULL_Q_BIO)
+ dev->mbps = 0;
+}
+
+static int null_add_dev(struct nullb_device *dev)
+{
+ struct nullb *nullb;
+ int rv;
+
+ null_validate_conf(dev);
+
+ nullb = kzalloc_node(sizeof(*nullb), GFP_KERNEL, dev->home_node);
+ if (!nullb) {
+ rv = -ENOMEM;
+ goto out;
+ }
+ nullb->dev = dev;
+ dev->nullb = nullb;
+
+ spin_lock_init(&nullb->lock);
+
+ rv = setup_queues(nullb);
+ if (rv)
+ goto out_free_nullb;
+
+ if (dev->queue_mode == NULL_Q_MQ) {
+ if (shared_tags) {
+ nullb->tag_set = &tag_set;
+ rv = 0;
+ } else {
+ nullb->tag_set = &nullb->__tag_set;
+ rv = null_init_tag_set(nullb, nullb->tag_set);
+ }
+
+ if (rv)
+ goto out_cleanup_queues;
+
+ nullb->q = blk_mq_init_queue(nullb->tag_set);
+ if (IS_ERR(nullb->q)) {
+ rv = -ENOMEM;
+ goto out_cleanup_tags;
+ }
+ null_init_queues(nullb);
+ } else if (dev->queue_mode == NULL_Q_BIO) {
+ nullb->q = blk_alloc_queue_node(GFP_KERNEL, dev->home_node);
+ if (!nullb->q) {
+ rv = -ENOMEM;
+ goto out_cleanup_queues;
+ }
+ blk_queue_make_request(nullb->q, null_queue_bio);
+ rv = init_driver_queues(nullb);
+ if (rv)
+ goto out_cleanup_blk_queue;
+ } else {
+ nullb->q = blk_init_queue_node(null_request_fn, &nullb->lock,
+ dev->home_node);
+ if (!nullb->q) {
+ rv = -ENOMEM;
+ goto out_cleanup_queues;
+ }
+ blk_queue_prep_rq(nullb->q, null_rq_prep_fn);
+ blk_queue_softirq_done(nullb->q, null_softirq_done_fn);
+ rv = init_driver_queues(nullb);
+ if (rv)
+ goto out_cleanup_blk_queue;
+ }
+
+ if (dev->mbps) {
+ set_bit(NULLB_DEV_FL_THROTTLED, &dev->flags);
+ nullb_setup_bwtimer(nullb);
+ }
+
+ if (dev->cache_size > 0) {
+ set_bit(NULLB_DEV_FL_CACHE, &nullb->dev->flags);
+ blk_queue_write_cache(nullb->q, true, true);
+ blk_queue_flush_queueable(nullb->q, true);
+ }
+
+ nullb->q->queuedata = nullb;
+ queue_flag_set_unlocked(QUEUE_FLAG_NONROT, nullb->q);
+ queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, nullb->q);
+
+ mutex_lock(&lock);
+ nullb->index = ida_simple_get(&nullb_indexes, 0, 0, GFP_KERNEL);
+ dev->index = nullb->index;
+ mutex_unlock(&lock);
+
+ blk_queue_logical_block_size(nullb->q, dev->blocksize);
+ blk_queue_physical_block_size(nullb->q, dev->blocksize);
+
+ null_config_discard(nullb);
+
+ sprintf(nullb->disk_name, "nullb%d", nullb->index);
+
+ if (dev->use_lightnvm)
+ rv = null_nvm_register(nullb);
+ else
+ rv = null_gendisk_register(nullb);
+
+ if (rv)
+ goto out_cleanup_blk_queue;
+
+ mutex_lock(&lock);
+ list_add_tail(&nullb->list, &nullb_list);
+ mutex_unlock(&lock);
+
+ return 0;
+out_cleanup_blk_queue:
+ blk_cleanup_queue(nullb->q);
+out_cleanup_tags:
+ if (dev->queue_mode == NULL_Q_MQ && nullb->tag_set == &nullb->__tag_set)
+ blk_mq_free_tag_set(nullb->tag_set);
+out_cleanup_queues:
+ cleanup_queues(nullb);
+out_free_nullb:
+ kfree(nullb);
+ dev->nullb = NULL;
+out:
+ return rv;
+}
+
+static int __init null_init(void)
+{
+ int ret = 0;
+ unsigned int i;
+ struct nullb *nullb;
+ struct nullb_device *dev;
+
+ if (g_bs > PAGE_SIZE) {
+ pr_warn("null_blk: invalid block size\n");
+ pr_warn("null_blk: defaults block size to %lu\n", PAGE_SIZE);
+ g_bs = PAGE_SIZE;
+ }
+
+ if (g_use_lightnvm && g_bs != 4096) {
+ pr_warn("null_blk: LightNVM only supports 4k block size\n");
+ pr_warn("null_blk: defaults block size to 4k\n");
+ g_bs = 4096;
+ }
+
+ if (g_use_lightnvm && g_queue_mode != NULL_Q_MQ) {
+ pr_warn("null_blk: LightNVM only supported for blk-mq\n");
+ pr_warn("null_blk: defaults queue mode to blk-mq\n");
+ g_queue_mode = NULL_Q_MQ;
+ }
+
+ if (g_queue_mode == NULL_Q_MQ && g_use_per_node_hctx) {
+ if (g_submit_queues != nr_online_nodes) {
+ pr_warn("null_blk: submit_queues param is set to %u.\n",
+ nr_online_nodes);
+ g_submit_queues = nr_online_nodes;
+ }
+ } else if (g_submit_queues > nr_cpu_ids)
+ g_submit_queues = nr_cpu_ids;
+ else if (g_submit_queues <= 0)
+ g_submit_queues = 1;
+
+ if (g_queue_mode == NULL_Q_MQ && shared_tags) {
+ ret = null_init_tag_set(NULL, &tag_set);
+ if (ret)
+ return ret;
+ }
+
+ config_group_init(&nullb_subsys.su_group);
+ mutex_init(&nullb_subsys.su_mutex);
+
+ ret = configfs_register_subsystem(&nullb_subsys);
+ if (ret)
+ goto err_tagset;
+
+ mutex_init(&lock);
+
+ null_major = register_blkdev(0, "nullb");
+ if (null_major < 0) {
+ ret = null_major;
+ goto err_conf;
+ }
+
+ if (g_use_lightnvm) {
+ ppa_cache = kmem_cache_create("ppa_cache", 64 * sizeof(u64),
+ 0, 0, NULL);
+ if (!ppa_cache) {
+ pr_err("null_blk: unable to create ppa cache\n");
+ ret = -ENOMEM;
+ goto err_ppa;
+ }
+ }
+
+ for (i = 0; i < nr_devices; i++) {
+ dev = null_alloc_dev();
+ if (!dev) {
+ ret = -ENOMEM;
+ goto err_dev;
+ }
+ ret = null_add_dev(dev);
+ if (ret) {
+ null_free_dev(dev);
+ goto err_dev;
+ }
+ }
+
+ pr_info("null: module loaded\n");
+ return 0;
+
+err_dev:
+ while (!list_empty(&nullb_list)) {
+ nullb = list_entry(nullb_list.next, struct nullb, list);
+ dev = nullb->dev;
+ null_del_dev(nullb);
+ null_free_dev(dev);
+ }
+ kmem_cache_destroy(ppa_cache);
+err_ppa:
+ unregister_blkdev(null_major, "nullb");
+err_conf:
+ configfs_unregister_subsystem(&nullb_subsys);
+err_tagset:
+ if (g_queue_mode == NULL_Q_MQ && shared_tags)
+ blk_mq_free_tag_set(&tag_set);
+ return ret;
+}
+
+static void __exit null_exit(void)
+{
+ struct nullb *nullb;
+
+ configfs_unregister_subsystem(&nullb_subsys);
+
+ unregister_blkdev(null_major, "nullb");
+
+ mutex_lock(&lock);
+ while (!list_empty(&nullb_list)) {
+ struct nullb_device *dev;
+
+ nullb = list_entry(nullb_list.next, struct nullb, list);
+ dev = nullb->dev;
+ null_del_dev(nullb);
+ null_free_dev(dev);
+ }
+ mutex_unlock(&lock);
+
+ if (g_queue_mode == NULL_Q_MQ && shared_tags)
+ blk_mq_free_tag_set(&tag_set);
+
+ kmem_cache_destroy(ppa_cache);
+}
+
+module_init(null_init);
+module_exit(null_exit);
+
+MODULE_AUTHOR("Jens Axboe <axboe@kernel.dk>");
+MODULE_LICENSE("GPL");