NVMe: Add discard support for capable devices

This adds discard support to block queues if the nvme device is capable of
deallocating blocks as indicated by the controller's optional command support.
A discard flagged bio request will submit an NVMe deallocate Data Set
Management command for the requested blocks.

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

1 files changed, 32 insertions, 0 deletions

diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index 4fa3b0b9b071..bde44c1fd213 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -107,6 +107,12 @@ struct nvme_id_ctrl {
         __u8                    vs[1024];
 };
 
+enum {
+        NVME_CTRL_ONCS_COMPARE                  = 1 << 0,
+        NVME_CTRL_ONCS_WRITE_UNCORRECTABLE      = 1 << 1,
+        NVME_CTRL_ONCS_DSM                      = 1 << 2,
+};
+
 struct nvme_lbaf {
         __le16                  ms;
         __u8                    ds;
@@ -246,6 +252,31 @@ enum {
         NVME_RW_DSM_COMPRESSED          = 1 << 7,
 };
 
+struct nvme_dsm_cmd {
+        __u8                    opcode;
+        __u8                    flags;
+        __u16                   command_id;
+        __le32                  nsid;
+        __u64                   rsvd2[2];
+        __le64                  prp1;
+        __le64                  prp2;
+        __le32                  nr;
+        __le32                  attributes;
+        __u32                   rsvd12[4];
+};
+
+enum {
+        NVME_DSMGMT_IDR         = 1 << 0,
+        NVME_DSMGMT_IDW         = 1 << 1,
+        NVME_DSMGMT_AD          = 1 << 2,
+};
+
+struct nvme_dsm_range {
+        __le32                  cattr;
+        __le32                  nlb;
+        __le64                  slba;
+};
+
 /* Admin commands */
 
 enum nvme_admin_opcode {
@@ -372,6 +403,7 @@ struct nvme_command {
                 struct nvme_create_sq create_sq;
                 struct nvme_delete_queue delete_queue;
                 struct nvme_download_firmware dlfw;
+                struct nvme_dsm_cmd dsm;
         };
 };