diff options
| author | Bart Van Assche <bvanassche@acm.org> | 2021-10-20 14:40:24 -0700 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2021-10-26 23:24:50 -0400 |
| commit | 1ea7d8026300f72344bb574a12667f9543f73348 (patch) | |
| tree | 5f67c6a24671ff0bf59d4a7d338b10f5ac7ae9b8 | |
| parent | 9a868c8ad3f467fe3487e3d96fc0e2f3c90f34f9 (diff) | |
scsi: ufs: core: Micro-optimize ufshcd_map_sg()
Replace two cpu_to_le32() calls by a single cpu_to_le64() call.
Additionally, issue a warning if the length of an scatter gather list
element exceeds what is allowed by the UFSHCI specification.
Link: https://lore.kernel.org/r/20211020214024.2007615-11-bvanassche@acm.org
Acked-by: Avri Altman <Avri.Altman@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
| -rw-r--r-- | drivers/scsi/ufs/ufshcd.c | 19 | ||||
| -rw-r--r-- | drivers/scsi/ufs/ufshci.h | 6 |
2 files changed, 15 insertions, 10 deletions
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index dde4d3f607f2..04cb67995750 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -2379,12 +2379,19 @@ static int ufshcd_map_sg(struct ufs_hba *hba, struct ufshcd_lrb *lrbp) prd_table = lrbp->ucd_prdt_ptr; scsi_for_each_sg(cmd, sg, sg_segments, i) { - prd_table[i].size = - cpu_to_le32(((u32) sg_dma_len(sg))-1); - prd_table[i].base_addr = - cpu_to_le32(lower_32_bits(sg->dma_address)); - prd_table[i].upper_addr = - cpu_to_le32(upper_32_bits(sg->dma_address)); + const unsigned int len = sg_dma_len(sg); + + /* + * From the UFSHCI spec: "Data Byte Count (DBC): A '0' + * based value that indicates the length, in bytes, of + * the data block. A maximum of length of 256KB may + * exist for any entry. Bits 1:0 of this field shall be + * 11b to indicate Dword granularity. A value of '3' + * indicates 4 bytes, '7' indicates 8 bytes, etc." + */ + WARN_ONCE(len > 256 * 1024, "len = %#x\n", len); + prd_table[i].size = cpu_to_le32(len - 1); + prd_table[i].addr = cpu_to_le64(sg->dma_address); prd_table[i].reserved = 0; } } else { diff --git a/drivers/scsi/ufs/ufshci.h b/drivers/scsi/ufs/ufshci.h index f66cf9e477cb..6a295c88d850 100644 --- a/drivers/scsi/ufs/ufshci.h +++ b/drivers/scsi/ufs/ufshci.h @@ -415,14 +415,12 @@ enum { /** * struct ufshcd_sg_entry - UFSHCI PRD Entry - * @base_addr: Lower 32bit physical address DW-0 - * @upper_addr: Upper 32bit physical address DW-1 + * @addr: Physical address; DW-0 and DW-1. * @reserved: Reserved for future use DW-2 * @size: size of physical segment DW-3 */ struct ufshcd_sg_entry { - __le32 base_addr; - __le32 upper_addr; + __le64 addr; __le32 reserved; __le32 size; }; |