diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c index e09ad6cc6dec5f689f4ad5175b5ed91d3813e263..82b4ffb6eefa7bc5f2690f31d40fb10c2c0e3993 100644 --- a/drivers/block/nvme-core.c +++ b/drivers/block/nvme-core.c @@ -72,6 +72,10 @@ module_param(nvme_char_major, int, 0); static int use_threaded_interrupts; module_param(use_threaded_interrupts, int, 0); +static bool use_cmb_sqes = true; +module_param(use_cmb_sqes, bool, 0644); +MODULE_PARM_DESC(use_cmb_sqes, "use controller's memory buffer for I/O SQes"); + static DEFINE_SPINLOCK(dev_list_lock); static LIST_HEAD(dev_list); static struct task_struct *nvme_thread; @@ -103,6 +107,7 @@ struct nvme_queue { char irqname[24]; /* nvme4294967295-65535\0 */ spinlock_t q_lock; struct nvme_command *sq_cmds; + struct nvme_command __iomem *sq_cmds_io; volatile struct nvme_completion *cqes; struct blk_mq_tags **tags; dma_addr_t sq_dma_addr; @@ -383,7 +388,11 @@ static int __nvme_submit_cmd(struct nvme_queue *nvmeq, struct nvme_command *cmd) { u16 tail = nvmeq->sq_tail; - memcpy(&nvmeq->sq_cmds[tail], cmd, sizeof(*cmd)); + if (nvmeq->sq_cmds_io) + memcpy_toio(&nvmeq->sq_cmds_io[tail], cmd, sizeof(*cmd)); + else + memcpy(&nvmeq->sq_cmds[tail], cmd, sizeof(*cmd)); + if (++tail == nvmeq->q_depth) tail = 0; writel(tail, nvmeq->q_db); @@ -1364,7 +1373,8 @@ static void nvme_free_queue(struct nvme_queue *nvmeq) { dma_free_coherent(nvmeq->q_dmadev, CQ_SIZE(nvmeq->q_depth), (void *)nvmeq->cqes, nvmeq->cq_dma_addr); - dma_free_coherent(nvmeq->q_dmadev, SQ_SIZE(nvmeq->q_depth), + if (nvmeq->sq_cmds) + dma_free_coherent(nvmeq->q_dmadev, SQ_SIZE(nvmeq->q_depth), nvmeq->sq_cmds, nvmeq->sq_dma_addr); kfree(nvmeq); } @@ -1437,6 +1447,46 @@ static void nvme_disable_queue(struct nvme_dev *dev, int qid) spin_unlock_irq(&nvmeq->q_lock); } +static int nvme_cmb_qdepth(struct nvme_dev *dev, int nr_io_queues, + int entry_size) +{ + int q_depth = dev->q_depth; + unsigned q_size_aligned = roundup(q_depth * entry_size, dev->page_size); + + if (q_size_aligned * nr_io_queues > dev->cmb_size) { + q_depth = rounddown(dev->cmb_size / nr_io_queues, + dev->page_size) / entry_size; + + /* + * Ensure the reduced q_depth is above some threshold where it + * would be better to map queues in system memory with the + * original depth + */ + if (q_depth < 64) + return -ENOMEM; + } + + return q_depth; +} + +static int nvme_alloc_sq_cmds(struct nvme_dev *dev, struct nvme_queue *nvmeq, + int qid, int depth) +{ + if (qid && dev->cmb && use_cmb_sqes && NVME_CMB_SQS(dev->cmbsz)) { + unsigned offset = (qid - 1) * + roundup(SQ_SIZE(depth), dev->page_size); + nvmeq->sq_dma_addr = dev->cmb_dma_addr + offset; + nvmeq->sq_cmds_io = dev->cmb + offset; + } else { + nvmeq->sq_cmds = dma_alloc_coherent(dev->dev, SQ_SIZE(depth), + &nvmeq->sq_dma_addr, GFP_KERNEL); + if (!nvmeq->sq_cmds) + return -ENOMEM; + } + + return 0; +} + static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid, int depth) { @@ -1449,9 +1499,7 @@ static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid, if (!nvmeq->cqes) goto free_nvmeq; - nvmeq->sq_cmds = dma_alloc_coherent(dev->dev, SQ_SIZE(depth), - &nvmeq->sq_dma_addr, GFP_KERNEL); - if (!nvmeq->sq_cmds) + if (nvme_alloc_sq_cmds(dev, nvmeq, qid, depth)) goto free_cqdma; nvmeq->q_dmadev = dev->dev; @@ -2149,6 +2197,58 @@ static int set_queue_count(struct nvme_dev *dev, int count) return min(result & 0xffff, result >> 16) + 1; } +static void __iomem *nvme_map_cmb(struct nvme_dev *dev) +{ + u64 szu, size, offset; + u32 cmbloc; + resource_size_t bar_size; + struct pci_dev *pdev = to_pci_dev(dev->dev); + void __iomem *cmb; + dma_addr_t dma_addr; + + if (!use_cmb_sqes) + return NULL; + + dev->cmbsz = readl(&dev->bar->cmbsz); + if (!(NVME_CMB_SZ(dev->cmbsz))) + return NULL; + + cmbloc = readl(&dev->bar->cmbloc); + + szu = (u64)1 << (12 + 4 * NVME_CMB_SZU(dev->cmbsz)); + size = szu * NVME_CMB_SZ(dev->cmbsz); + offset = szu * NVME_CMB_OFST(cmbloc); + bar_size = pci_resource_len(pdev, NVME_CMB_BIR(cmbloc)); + + if (offset > bar_size) + return NULL; + + /* + * Controllers may support a CMB size larger than their BAR, + * for example, due to being behind a bridge. Reduce the CMB to + * the reported size of the BAR + */ + if (size > bar_size - offset) + size = bar_size - offset; + + dma_addr = pci_resource_start(pdev, NVME_CMB_BIR(cmbloc)) + offset; + cmb = ioremap_wc(dma_addr, size); + if (!cmb) + return NULL; + + dev->cmb_dma_addr = dma_addr; + dev->cmb_size = size; + return cmb; +} + +static inline void nvme_release_cmb(struct nvme_dev *dev) +{ + if (dev->cmb) { + iounmap(dev->cmb); + dev->cmb = NULL; + } +} + static size_t db_bar_size(struct nvme_dev *dev, unsigned nr_io_queues) { return 4096 + ((nr_io_queues + 1) * 8 * dev->db_stride); @@ -2167,6 +2267,15 @@ static int nvme_setup_io_queues(struct nvme_dev *dev) if (result < nr_io_queues) nr_io_queues = result; + if (dev->cmb && NVME_CMB_SQS(dev->cmbsz)) { + result = nvme_cmb_qdepth(dev, nr_io_queues, + sizeof(struct nvme_command)); + if (result > 0) + dev->q_depth = result; + else + nvme_release_cmb(dev); + } + size = db_bar_size(dev, nr_io_queues); if (size > 8192) { iounmap(dev->bar); @@ -2430,6 +2539,8 @@ static int nvme_dev_map(struct nvme_dev *dev) dev->q_depth = min_t(int, NVME_CAP_MQES(cap) + 1, NVME_Q_DEPTH); dev->db_stride = 1 << NVME_CAP_STRIDE(cap); dev->dbs = ((void __iomem *)dev->bar) + 4096; + if (readl(&dev->bar->vs) >= NVME_VS(1, 2)) + dev->cmb = nvme_map_cmb(dev); return 0; @@ -3135,6 +3246,7 @@ static void nvme_remove(struct pci_dev *pdev) nvme_dev_remove_admin(dev); device_destroy(nvme_class, MKDEV(nvme_char_major, dev->instance)); nvme_free_queues(dev, 0); + nvme_release_cmb(dev); nvme_release_prp_pools(dev); kref_put(&dev->kref, nvme_free_dev); } diff --git a/include/linux/nvme.h b/include/linux/nvme.h index c0d94ed8ce9aabde3d5c140c93948ede3d462546..fa3fe160c6cbcd0b8bae05baf6488d03067d5e07 100644 --- a/include/linux/nvme.h +++ b/include/linux/nvme.h @@ -32,6 +32,8 @@ struct nvme_bar { __u32 aqa; /* Admin Queue Attributes */ __u64 asq; /* Admin SQ Base Address */ __u64 acq; /* Admin CQ Base Address */ + __u32 cmbloc; /* Controller Memory Buffer Location */ + __u32 cmbsz; /* Controller Memory Buffer Size */ }; #define NVME_CAP_MQES(cap) ((cap) & 0xffff) @@ -40,6 +42,17 @@ struct nvme_bar { #define NVME_CAP_MPSMIN(cap) (((cap) >> 48) & 0xf) #define NVME_CAP_MPSMAX(cap) (((cap) >> 52) & 0xf) +#define NVME_CMB_BIR(cmbloc) ((cmbloc) & 0x7) +#define NVME_CMB_OFST(cmbloc) (((cmbloc) >> 12) & 0xfffff) +#define NVME_CMB_SZ(cmbsz) (((cmbsz) >> 12) & 0xfffff) +#define NVME_CMB_SZU(cmbsz) (((cmbsz) >> 8) & 0xf) + +#define NVME_CMB_WDS(cmbsz) ((cmbsz) & 0x10) +#define NVME_CMB_RDS(cmbsz) ((cmbsz) & 0x8) +#define NVME_CMB_LISTS(cmbsz) ((cmbsz) & 0x4) +#define NVME_CMB_CQS(cmbsz) ((cmbsz) & 0x2) +#define NVME_CMB_SQS(cmbsz) ((cmbsz) & 0x1) + enum { NVME_CC_ENABLE = 1 << 0, NVME_CC_CSS_NVM = 0 << 4, @@ -100,6 +113,10 @@ struct nvme_dev { u32 max_hw_sectors; u32 stripe_size; u32 page_size; + void __iomem *cmb; + dma_addr_t cmb_dma_addr; + u64 cmb_size; + u32 cmbsz; u16 oncs; u16 abort_limit; u8 event_limit;