NVMe: Set block queue max sectors

Set the max hw sectors in a namespace's request queue if the nvme device
has a max data transfer size.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>

diff --git a/drivers/block/nvme.c b/drivers/block/nvme.c
index 7bcd882..11951fa 100644 (file)
--- a/drivers/block/nvme.c
+++ b/drivers/block/nvme.c
@@ -78,6 +78,7 @@ struct nvme_dev {
        char serial[20];
        char model[40];
        char firmware_rev[8];
+       u32 max_hw_sectors;
 };
 
 /*
@@ -1344,6 +1345,8 @@ static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, int nsid,
        lbaf = id->flbas & 0xf;
        ns->lba_shift = id->lbaf[lbaf].ds;
        blk_queue_logical_block_size(ns->queue, 1 << ns->lba_shift);
+       if (dev->max_hw_sectors)
+               blk_queue_max_hw_sectors(ns->queue, dev->max_hw_sectors);
 
        disk->major = nvme_major;
        disk->minors = NVME_MINORS;
@@ -1485,6 +1488,10 @@ static int __devinit nvme_dev_add(struct nvme_dev *dev)
        memcpy(dev->serial, ctrl->sn, sizeof(ctrl->sn));
        memcpy(dev->model, ctrl->mn, sizeof(ctrl->mn));
        memcpy(dev->firmware_rev, ctrl->fr, sizeof(ctrl->fr));
+       if (ctrl->mdts) {
+               int shift = NVME_CAP_MPSMIN(readq(&dev->bar->cap)) + 12;
+               dev->max_hw_sectors = 1 << (ctrl->mdts + shift - 9);
+       }
 
        id_ns = mem;
        for (i = 1; i <= nn; i++) {

diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index 9490a00..8c71d20 100644 (file)
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -37,6 +37,7 @@ struct nvme_bar {
 
 #define NVME_CAP_TIMEOUT(cap)  (((cap) >> 24) & 0xff)
 #define NVME_CAP_STRIDE(cap)   (((cap) >> 32) & 0xf)
+#define NVME_CAP_MPSMIN(cap)   (((cap) >> 48) & 0xf)
 
 enum {
        NVME_CC_ENABLE          = 1 << 0,