Adding blk-mq support to the pmem driver in addition to the direct bio
support. This allows for hardware offloading via DMA engines. By default
the bio method will be enabled. The blk-mq support can be turned on via
module parameter queue_mode=1.
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
---
drivers/nvdimm/pmem.c | 131 +++++++++++++++++++++++++++++++++++++++++++++----
drivers/nvdimm/pmem.h | 3 +
2 files changed, 122 insertions(+), 12 deletions(-)
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index c544d46..347835b 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -31,10 +31,24 @@
#include <linux/pmem.h>
#include <linux/dax.h>
#include <linux/nd.h>
+#include <linux/blk-mq.h>
#include "pmem.h"
#include "pfn.h"
#include "nd.h"
+enum {
+ PMEM_Q_BIO = 0,
+ PMEM_Q_MQ = 1,
+};
+
+static int queue_mode = PMEM_Q_BIO;
+module_param(queue_mode, int, 0444);
+MODULE_PARM_DESC(queue_mode, "Pmem Queue Mode");
+
+struct pmem_cmd {
+ struct request *rq;
+};
+
static struct device *to_dev(struct pmem_device *pmem)
{
/*
@@ -239,9 +253,12 @@ static const struct dax_operations pmem_dax_ops = {
.direct_access = pmem_dax_direct_access,
};
-static void pmem_release_queue(void *q)
+static void pmem_release_queue(void *pmem)
{
- blk_cleanup_queue(q);
+
+ blk_cleanup_queue(((struct pmem_device *)pmem)->q);
+ if (queue_mode == PMEM_Q_MQ)
+ blk_mq_free_tag_set(&((struct pmem_device *)pmem)->tag_set);
}
static void pmem_freeze_queue(void *q)
@@ -259,6 +276,65 @@ static void pmem_release_disk(void *__pmem)
put_disk(pmem->disk);
}
+static int pmem_handle_cmd(struct pmem_cmd *cmd)
+{
+ struct request *req = cmd->rq;
+ struct request_queue *q = req->q;
+ struct pmem_device *pmem = q->queuedata;
+ struct nd_region *nd_region = to_region(pmem);
+ struct bio_vec bvec;
+ struct req_iterator iter;
+ int rc = 0;
+
+ if (req->cmd_flags & REQ_FLUSH)
+ nvdimm_flush(nd_region);
+
+ rq_for_each_segment(bvec, req, iter) {
+ rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len,
+ bvec.bv_offset, op_is_write(req_op(req)),
+ iter.iter.bi_sector);
+ if (rc < 0)
+ break;
+ }
+
+ if (req->cmd_flags & REQ_FUA)
+ nvdimm_flush(nd_region);
+
+ blk_mq_end_request(cmd->rq, rc);
+
+ return 0;
+}
+
+static int pmem_queue_rq(struct blk_mq_hw_ctx *hctx,
+ const struct blk_mq_queue_data *bd)
+{
+ struct pmem_cmd *cmd = blk_mq_rq_to_pdu(bd->rq);
+ int rc;
+
+ cmd->rq = bd->rq;
+
+ blk_mq_start_request(bd->rq);
+
+ rc = pmem_handle_cmd(cmd);
+ if (rc < 0)
+ rc = BLK_MQ_RQ_QUEUE_ERROR;
+ else
+ rc = BLK_MQ_RQ_QUEUE_OK;
+
+ return rc;
+}
+
+static int pmem_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
+ unsigned int index)
+{
+ return 0;
+}
+
+static const struct blk_mq_ops pmem_mq_ops = {
+ .queue_rq = pmem_queue_rq,
+ .init_hctx = pmem_init_hctx,
+};
+
static int pmem_attach_disk(struct device *dev,
struct nd_namespace_common *ndns)
{
@@ -275,6 +351,7 @@ static int pmem_attach_disk(struct device *dev,
struct request_queue *q;
struct gendisk *disk;
void *addr;
+ int rc;
/* while nsio_rw_bytes is active, parse a pfn info block if present */
if (is_nd_pfn(dev)) {
@@ -303,17 +380,47 @@ static int pmem_attach_disk(struct device *dev,
return -EBUSY;
}
- q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev));
- if (!q)
- return -ENOMEM;
+ if (queue_mode == PMEM_Q_MQ) {
+ pmem->tag_set.ops = &pmem_mq_ops;
+ pmem->tag_set.nr_hw_queues = nr_online_nodes;
+ pmem->tag_set.queue_depth = 64;
+ pmem->tag_set.numa_node = dev_to_node(dev);
+ pmem->tag_set.cmd_size = sizeof(struct pmem_cmd);
+ pmem->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
+ pmem->tag_set.driver_data = pmem;
+
+ rc = blk_mq_alloc_tag_set(&pmem->tag_set);
+ if (rc < 0)
+ return rc;
+
+ pmem->q = blk_mq_init_queue(&pmem->tag_set);
+ if (IS_ERR(pmem->q)) {
+ blk_mq_free_tag_set(&pmem->tag_set);
+ return -ENOMEM;
+ }
- if (devm_add_action_or_reset(dev, pmem_release_queue, q))
- return -ENOMEM;
+ if (devm_add_action_or_reset(dev, pmem_release_queue, pmem)) {
+ blk_mq_free_tag_set(&pmem->tag_set);
+ return -ENOMEM;
+ }
+ } else if (queue_mode == PMEM_Q_BIO) {
+ pmem->q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev));
+ if (!pmem->q)
+ return -ENOMEM;
+
+ if (devm_add_action_or_reset(dev, pmem_release_queue, pmem))
+ return -ENOMEM;
+
+ blk_queue_make_request(pmem->q, pmem_make_request);
+ } else {
+ dev_warn(dev, "Invalid queue mode: %d\n", queue_mode);
+ return -EINVAL;
+ }
pmem->pfn_flags = PFN_DEV;
if (is_nd_pfn(dev)) {
- addr = devm_memremap_pages(dev, &pfn_res, &q->q_usage_counter,
- altmap);
+ addr = devm_memremap_pages(dev, &pfn_res,
+ &pmem->q->q_usage_counter, altmap);
pfn_sb = nd_pfn->pfn_sb;
pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
pmem->pfn_pad = resource_size(res) - resource_size(&pfn_res);
@@ -322,7 +429,7 @@ static int pmem_attach_disk(struct device *dev,
res->start += pmem->data_offset;
} else if (pmem_should_map_pages(dev)) {
addr = devm_memremap_pages(dev, &nsio->res,
- &q->q_usage_counter, NULL);
+ &pmem->q->q_usage_counter, NULL);
pmem->pfn_flags |= PFN_MAP;
} else
addr = devm_memremap(dev, pmem->phys_addr,
@@ -332,7 +439,7 @@ static int pmem_attach_disk(struct device *dev,
* At release time the queue must be frozen before
* devm_memremap_pages is unwound
*/
- if (devm_add_action_or_reset(dev, pmem_freeze_queue, q))
+ if (devm_add_action_or_reset(dev, pmem_freeze_queue, pmem->q))
return -ENOMEM;
if (IS_ERR(addr))
@@ -354,7 +461,7 @@ static int pmem_attach_disk(struct device *dev,
pmem->disk = disk;
disk->fops = &pmem_fops;
- disk->queue = q;
+ disk->queue = pmem->q;
disk->flags = GENHD_FL_EXT_DEVT;
nvdimm_namespace_disk_name(ndns, disk->disk_name);
set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
diff --git a/drivers/nvdimm/pmem.h b/drivers/nvdimm/pmem.h
index 7f4dbd7..1836c7b 100644
--- a/drivers/nvdimm/pmem.h
+++ b/drivers/nvdimm/pmem.h
@@ -4,6 +4,7 @@
#include <linux/types.h>
#include <linux/pfn_t.h>
#include <linux/fs.h>
+#include <linux/blk-mq.h>
/* this definition is in it's own header for tools/testing/nvdimm to consume */
struct pmem_device {
@@ -20,6 +21,8 @@ struct pmem_device {
struct badblocks bb;
struct dax_device *dax_dev;
struct gendisk *disk;
+ struct blk_mq_tag_set tag_set;
+ struct request_queue *q;
};
long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
--
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