nvme: simplify and cleanup the READ/WRITE SCSI CDB parsing code

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/drivers/block/nvme-scsi.c b/drivers/block/nvme-scsi.c
index 9fe0a2c5a9bedf3898d4ab6e6a201615e3078246..b119143e4433698456d9c0c548e7bd3a7bf997e5 100644 (file)
--- a/drivers/block/nvme-scsi.c
+++ b/drivers/block/nvme-scsi.c
@@ -107,12 +107,6 @@ static int sg_version_num = 30534; /* 2 digits for each component */
 #define EXTENDED_INQUIRY_DATA_PAGE_LENGTH              0x3C
 #define RESERVED_FIELD                                 0
 
-/* SCSI READ/WRITE Defines */
-#define IO_CDB_WP_MASK                                 0xE0
-#define IO_CDB_WP_SHIFT                                        5
-#define IO_CDB_FUA_MASK                                        0x8
-#define IO_6_CDB_LBA_MASK                              0x001FFFFF
-
 /* Mode Sense/Select defines */
 #define MODE_PAGE_INFO_EXCEP                           0x1C
 #define MODE_PAGE_CACHING                              0x08
@@ -1763,48 +1757,6 @@ static int nvme_trans_fmt_send_cmd(struct nvme_ns *ns, struct sg_io_hdr *hdr,
        return res;
 }
 
-/* Read/Write Helper Functions */
-
-static inline void nvme_trans_get_io_cdb6(u8 *cmd,
-                                       struct nvme_trans_io_cdb *cdb_info)
-{
-       cdb_info->fua = 0;
-       cdb_info->prot_info = 0;
-       cdb_info->lba = get_unaligned_be32(&cmd[0]) & IO_6_CDB_LBA_MASK;
-       cdb_info->xfer_len = cmd[4];
-
-       /* sbc3r27 sec 5.32 - TRANSFER LEN of 0 implies a 256 Block transfer */
-       if (cdb_info->xfer_len == 0)
-               cdb_info->xfer_len = 256;
-}
-
-static inline void nvme_trans_get_io_cdb10(u8 *cmd,
-                                       struct nvme_trans_io_cdb *cdb_info)
-{
-       cdb_info->fua = cmd[1] & IO_CDB_FUA_MASK;
-       cdb_info->prot_info = cmd[1] & IO_CDB_WP_MASK >> IO_CDB_WP_SHIFT;
-       cdb_info->lba = get_unaligned_be32(&cmd[2]);
-       cdb_info->xfer_len = get_unaligned_be16(&cmd[7]);
-}
-
-static inline void nvme_trans_get_io_cdb12(u8 *cmd,
-                                       struct nvme_trans_io_cdb *cdb_info)
-{
-       cdb_info->fua = cmd[1] & IO_CDB_FUA_MASK;
-       cdb_info->prot_info = cmd[1] & IO_CDB_WP_MASK >> IO_CDB_WP_SHIFT;
-       cdb_info->lba = get_unaligned_be32(&cmd[2]);
-       cdb_info->xfer_len = get_unaligned_be32(&cmd[6]);
-}
-
-static inline void nvme_trans_get_io_cdb16(u8 *cmd,
-                                       struct nvme_trans_io_cdb *cdb_info)
-{
-       cdb_info->fua = cmd[1] & IO_CDB_FUA_MASK;
-       cdb_info->prot_info = cmd[1] & IO_CDB_WP_MASK >> IO_CDB_WP_SHIFT;
-       cdb_info->lba = get_unaligned_be64(&cmd[2]);
-       cdb_info->xfer_len = get_unaligned_be32(&cmd[10]);
-}
-
 static inline u32 nvme_trans_io_get_num_cmds(struct sg_io_hdr *hdr,
                                        struct nvme_trans_io_cdb *cdb_info,
                                        u32 max_blocks)
@@ -1929,7 +1881,7 @@ static int nvme_trans_io(struct nvme_ns *ns, struct sg_io_hdr *hdr, u8 is_write,
                                                        u8 *cmd)
 {
        int res = 0;
-       struct nvme_trans_io_cdb cdb_info;
+       struct nvme_trans_io_cdb cdb_info = { 0, };
        u8 opcode = cmd[0];
        u64 xfer_bytes;
        u64 sum_iov_len = 0;
@@ -1937,23 +1889,41 @@ static int nvme_trans_io(struct nvme_ns *ns, struct sg_io_hdr *hdr, u8 is_write,
        int i;
        size_t not_copied;
 
-       /* Extract Fields from CDB */
+       /*
+        * The FUA and WPROTECT fields are not supported in 6-byte CDBs,
+        * but always in the same place for all others.
+        */
+       switch (opcode) {
+       case WRITE_6:
+       case READ_6:
+               break;
+       default:
+               cdb_info.fua = cmd[1] & 0x8;
+               cdb_info.prot_info = (cmd[1] & 0xe0) >> 5;
+       }
+
        switch (opcode) {
        case WRITE_6:
        case READ_6:
-               nvme_trans_get_io_cdb6(cmd, &cdb_info);
+               cdb_info.lba = get_unaligned_be24(&cmd[1]);
+               cdb_info.xfer_len = cmd[4];
+               if (cdb_info.xfer_len == 0)
+                       cdb_info.xfer_len = 256;
                break;
        case WRITE_10:
        case READ_10:
-               nvme_trans_get_io_cdb10(cmd, &cdb_info);
+               cdb_info.lba = get_unaligned_be32(&cmd[2]);
+               cdb_info.xfer_len = get_unaligned_be16(&cmd[7]);
                break;
        case WRITE_12:
        case READ_12:
-               nvme_trans_get_io_cdb12(cmd, &cdb_info);
+               cdb_info.lba = get_unaligned_be32(&cmd[2]);
+               cdb_info.xfer_len = get_unaligned_be32(&cmd[6]);
                break;
        case WRITE_16:
        case READ_16:
-               nvme_trans_get_io_cdb16(cmd, &cdb_info);
+               cdb_info.lba = get_unaligned_be64(&cmd[2]);
+               cdb_info.xfer_len = get_unaligned_be32(&cmd[10]);
                break;
        default:
                /* Will never really reach here */