*/
#define NVME_AQ_BLKMQ_DEPTH (NVME_AQ_DEPTH - NVME_NR_AERS)
+#define SGES_PER_PAGE (PAGE_SIZE / sizeof(struct nvme_sgl_desc))
+
static int use_threaded_interrupts;
module_param(use_threaded_interrupts, int, 0);
MODULE_PARM_DESC(max_host_mem_size_mb,
"Maximum Host Memory Buffer (HMB) size per controller (in MiB)");
+static unsigned int sgl_threshold = SZ_32K;
+module_param(sgl_threshold, uint, 0644);
+MODULE_PARM_DESC(sgl_threshold,
+ "Use SGLs when average request segment size is larger or equal to "
+ "this size. Use 0 to disable SGLs.");
+
static int io_queue_depth_set(const char *val, const struct kernel_param *kp);
static const struct kernel_param_ops io_queue_depth_ops = {
.set = io_queue_depth_set,
struct nvme_iod {
struct nvme_request req;
struct nvme_queue *nvmeq;
+ bool use_sgl;
int aborted;
int npages; /* In the PRP list. 0 means small pool in use */
int nents; /* Used in scatterlist */
return DIV_ROUND_UP(8 * nprps, PAGE_SIZE - 8);
}
-static unsigned int nvme_iod_alloc_size(struct nvme_dev *dev,
- unsigned int size, unsigned int nseg)
+/*
+ * Calculates the number of pages needed for the SGL segments. For example a 4k
+ * page can accommodate 256 SGL descriptors.
+ */
+static int nvme_pci_npages_sgl(unsigned int num_seg)
+{
+ return DIV_ROUND_UP(num_seg * sizeof(struct nvme_sgl_desc), PAGE_SIZE);
+}
+
+static unsigned int nvme_pci_iod_alloc_size(struct nvme_dev *dev,
+ unsigned int size, unsigned int nseg, bool use_sgl)
{
- return sizeof(__le64 *) * nvme_npages(size, dev) +
- sizeof(struct scatterlist) * nseg;
+ size_t alloc_size;
+
+ if (use_sgl)
+ alloc_size = sizeof(__le64 *) * nvme_pci_npages_sgl(nseg);
+ else
+ alloc_size = sizeof(__le64 *) * nvme_npages(size, dev);
+
+ return alloc_size + sizeof(struct scatterlist) * nseg;
}
-static unsigned int nvme_cmd_size(struct nvme_dev *dev)
+static unsigned int nvme_pci_cmd_size(struct nvme_dev *dev, bool use_sgl)
{
- return sizeof(struct nvme_iod) +
- nvme_iod_alloc_size(dev, NVME_INT_BYTES(dev), NVME_INT_PAGES);
+ unsigned int alloc_size = nvme_pci_iod_alloc_size(dev,
+ NVME_INT_BYTES(dev), NVME_INT_PAGES,
+ use_sgl);
+
+ return sizeof(struct nvme_iod) + alloc_size;
}
static int nvme_admin_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
nvmeq->sq_tail = tail;
}
-static __le64 **iod_list(struct request *req)
+static void **nvme_pci_iod_list(struct request *req)
{
struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
- return (__le64 **)(iod->sg + blk_rq_nr_phys_segments(req));
+ return (void **)(iod->sg + blk_rq_nr_phys_segments(req));
}
static blk_status_t nvme_init_iod(struct request *rq, struct nvme_dev *dev)
unsigned int size = blk_rq_payload_bytes(rq);
if (nseg > NVME_INT_PAGES || size > NVME_INT_BYTES(dev)) {
- iod->sg = kmalloc(nvme_iod_alloc_size(dev, size, nseg), GFP_ATOMIC);
+ size_t alloc_size = nvme_pci_iod_alloc_size(dev, size, nseg,
+ iod->use_sgl);
+
+ iod->sg = kmalloc(alloc_size, GFP_ATOMIC);
if (!iod->sg)
return BLK_STS_RESOURCE;
} else {
static void nvme_free_iod(struct nvme_dev *dev, struct request *req)
{
struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
- const int last_prp = dev->ctrl.page_size / 8 - 1;
+ const int last_prp = dev->ctrl.page_size / sizeof(__le64) - 1;
+ dma_addr_t dma_addr = iod->first_dma, next_dma_addr;
+
int i;
- __le64 **list = iod_list(req);
- dma_addr_t prp_dma = iod->first_dma;
if (iod->npages == 0)
- dma_pool_free(dev->prp_small_pool, list[0], prp_dma);
+ dma_pool_free(dev->prp_small_pool, nvme_pci_iod_list(req)[0],
+ dma_addr);
+
for (i = 0; i < iod->npages; i++) {
- __le64 *prp_list = list[i];
- dma_addr_t next_prp_dma = le64_to_cpu(prp_list[last_prp]);
- dma_pool_free(dev->prp_page_pool, prp_list, prp_dma);
- prp_dma = next_prp_dma;
+ void *addr = nvme_pci_iod_list(req)[i];
+
+ if (iod->use_sgl) {
+ struct nvme_sgl_desc *sg_list = addr;
+
+ next_dma_addr =
+ le64_to_cpu((sg_list[SGES_PER_PAGE - 1]).addr);
+ } else {
+ __le64 *prp_list = addr;
+
+ next_dma_addr = le64_to_cpu(prp_list[last_prp]);
+ }
+
+ dma_pool_free(dev->prp_page_pool, addr, dma_addr);
+ dma_addr = next_dma_addr;
}
if (iod->sg != iod->inline_sg)
}
}
-static blk_status_t nvme_setup_prps(struct nvme_dev *dev, struct request *req)
+static blk_status_t nvme_pci_setup_prps(struct nvme_dev *dev,
+ struct request *req, struct nvme_rw_command *cmnd)
{
struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
struct dma_pool *pool;
u32 page_size = dev->ctrl.page_size;
int offset = dma_addr & (page_size - 1);
__le64 *prp_list;
- __le64 **list = iod_list(req);
+ void **list = nvme_pci_iod_list(req);
dma_addr_t prp_dma;
int nprps, i;
+ iod->use_sgl = false;
+
length -= (page_size - offset);
if (length <= 0) {
iod->first_dma = 0;
- return BLK_STS_OK;
+ goto done;
}
dma_len -= (page_size - offset);
if (length <= page_size) {
iod->first_dma = dma_addr;
- return BLK_STS_OK;
+ goto done;
}
nprps = DIV_ROUND_UP(length, page_size);
dma_len = sg_dma_len(sg);
}
+done:
+ cmnd->dptr.prp1 = cpu_to_le64(sg_dma_address(iod->sg));
+ cmnd->dptr.prp2 = cpu_to_le64(iod->first_dma);
+
return BLK_STS_OK;
bad_sgl:
return BLK_STS_IOERR;
}
+static void nvme_pci_sgl_set_data(struct nvme_sgl_desc *sge,
+ struct scatterlist *sg)
+{
+ sge->addr = cpu_to_le64(sg_dma_address(sg));
+ sge->length = cpu_to_le32(sg_dma_len(sg));
+ sge->type = NVME_SGL_FMT_DATA_DESC << 4;
+}
+
+static void nvme_pci_sgl_set_seg(struct nvme_sgl_desc *sge,
+ dma_addr_t dma_addr, int entries)
+{
+ sge->addr = cpu_to_le64(dma_addr);
+ if (entries < SGES_PER_PAGE) {
+ sge->length = cpu_to_le32(entries * sizeof(*sge));
+ sge->type = NVME_SGL_FMT_LAST_SEG_DESC << 4;
+ } else {
+ sge->length = cpu_to_le32(PAGE_SIZE);
+ sge->type = NVME_SGL_FMT_SEG_DESC << 4;
+ }
+}
+
+static blk_status_t nvme_pci_setup_sgls(struct nvme_dev *dev,
+ struct request *req, struct nvme_rw_command *cmd)
+{
+ struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
+ int length = blk_rq_payload_bytes(req);
+ struct dma_pool *pool;
+ struct nvme_sgl_desc *sg_list;
+ struct scatterlist *sg = iod->sg;
+ int entries = iod->nents, i = 0;
+ dma_addr_t sgl_dma;
+
+ iod->use_sgl = true;
+
+ /* setting the transfer type as SGL */
+ cmd->flags = NVME_CMD_SGL_METABUF;
+
+ if (length == sg_dma_len(sg)) {
+ nvme_pci_sgl_set_data(&cmd->dptr.sgl, sg);
+ return BLK_STS_OK;
+ }
+
+ if (entries <= (256 / sizeof(struct nvme_sgl_desc))) {
+ pool = dev->prp_small_pool;
+ iod->npages = 0;
+ } else {
+ pool = dev->prp_page_pool;
+ iod->npages = 1;
+ }
+
+ sg_list = dma_pool_alloc(pool, GFP_ATOMIC, &sgl_dma);
+ if (!sg_list) {
+ iod->npages = -1;
+ return BLK_STS_RESOURCE;
+ }
+
+ nvme_pci_iod_list(req)[0] = sg_list;
+ iod->first_dma = sgl_dma;
+
+ nvme_pci_sgl_set_seg(&cmd->dptr.sgl, sgl_dma, entries);
+
+ do {
+ if (i == SGES_PER_PAGE) {
+ struct nvme_sgl_desc *old_sg_desc = sg_list;
+ struct nvme_sgl_desc *link = &old_sg_desc[i - 1];
+
+ sg_list = dma_pool_alloc(pool, GFP_ATOMIC, &sgl_dma);
+ if (!sg_list)
+ return BLK_STS_RESOURCE;
+
+ i = 0;
+ nvme_pci_iod_list(req)[iod->npages++] = sg_list;
+ sg_list[i++] = *link;
+ nvme_pci_sgl_set_seg(link, sgl_dma, entries);
+ }
+
+ nvme_pci_sgl_set_data(&sg_list[i++], sg);
+
+ length -= sg_dma_len(sg);
+ sg = sg_next(sg);
+ entries--;
+ } while (length > 0);
+
+ WARN_ON(entries > 0);
+ return BLK_STS_OK;
+}
+
+static inline bool nvme_pci_use_sgls(struct nvme_dev *dev, struct request *req)
+{
+ struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
+ unsigned int avg_seg_size;
+
+ avg_seg_size = DIV_ROUND_UP(blk_rq_payload_bytes(req),
+ blk_rq_nr_phys_segments(req));
+
+ if (!(dev->ctrl.sgls & ((1 << 0) | (1 << 1))))
+ return false;
+ if (!iod->nvmeq->qid)
+ return false;
+ if (!sgl_threshold || avg_seg_size < sgl_threshold)
+ return false;
+ return true;
+}
+
static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req,
struct nvme_command *cmnd)
{
DMA_ATTR_NO_WARN))
goto out;
- ret = nvme_setup_prps(dev, req);
+ if (nvme_pci_use_sgls(dev, req))
+ ret = nvme_pci_setup_sgls(dev, req, &cmnd->rw);
+ else
+ ret = nvme_pci_setup_prps(dev, req, &cmnd->rw);
+
if (ret != BLK_STS_OK)
goto out_unmap;
goto out_unmap;
}
- cmnd->rw.dptr.prp1 = cpu_to_le64(sg_dma_address(iod->sg));
- cmnd->rw.dptr.prp2 = cpu_to_le64(iod->first_dma);
if (blk_integrity_rq(req))
cmnd->rw.metadata = cpu_to_le64(sg_dma_address(&iod->meta_sg));
return BLK_STS_OK;
dev->admin_tagset.queue_depth = NVME_AQ_BLKMQ_DEPTH - 1;
dev->admin_tagset.timeout = ADMIN_TIMEOUT;
dev->admin_tagset.numa_node = dev_to_node(dev->dev);
- dev->admin_tagset.cmd_size = nvme_cmd_size(dev);
+ dev->admin_tagset.cmd_size = nvme_pci_cmd_size(dev, false);
dev->admin_tagset.flags = BLK_MQ_F_NO_SCHED;
dev->admin_tagset.driver_data = dev;
dev->tagset.numa_node = dev_to_node(dev->dev);
dev->tagset.queue_depth =
min_t(int, dev->q_depth, BLK_MQ_MAX_DEPTH) - 1;
- dev->tagset.cmd_size = nvme_cmd_size(dev);
+ dev->tagset.cmd_size = nvme_pci_cmd_size(dev, false);
+ if ((dev->ctrl.sgls & ((1 << 0) | (1 << 1))) && sgl_threshold) {
+ dev->tagset.cmd_size = max(dev->tagset.cmd_size,
+ nvme_pci_cmd_size(dev, true));
+ }
dev->tagset.flags = BLK_MQ_F_SHOULD_MERGE;
dev->tagset.driver_data = dev;