[PATCH] isci: T10 DIF support

[Dan Williams <dan.j.williams@intel.com>]

From: Dave Jiang <dave.jiang@intel.com>

This allows the controller to do WRITE_INSERT and READ_STRIP for SAS
disks that support protection information. SAS disks must be formatted
with protection information to use this feature via sg_format.

  sg3_utils-1.32 -- sg_format version 1.19 20110730
  sg_format usage:
  sg_format --format --verbose --pinfo /dev/sda

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---

for scsi-misc / 3.4

 drivers/scsi/isci/init.c             |    7 ++
 drivers/scsi/isci/request.c          |  148 ++++++++++++++++++++++++++++++++++
 drivers/scsi/isci/scu_task_context.h |   55 +++++++++----
 3 files changed, 194 insertions(+), 16 deletions(-)

diff --git a/drivers/scsi/isci/init.c b/drivers/scsi/isci/init.c
index 437f76b..2a63027 100644
--- a/drivers/scsi/isci/init.c
+++ b/drivers/scsi/isci/init.c
@@ -506,6 +506,13 @@ static int __devinit isci_pci_probe(struct pci_dev *pdev, const struct pci_devic
 			goto err_host_alloc;
 		}
 		pci_info->hosts[i] = h;
+
+		/* turn on DIF support */
+		scsi_host_set_prot(h->shost,
+				   SHOST_DIF_TYPE1_PROTECTION |
+				   SHOST_DIF_TYPE2_PROTECTION |
+				   SHOST_DIF_TYPE3_PROTECTION);
+		scsi_host_set_guard(h->shost, SHOST_DIX_GUARD_CRC);
 	}
 
 	err = isci_setup_interrupts(pdev);
diff --git a/drivers/scsi/isci/request.c b/drivers/scsi/isci/request.c
index 0e43efd..06e0541 100644
--- a/drivers/scsi/isci/request.c
+++ b/drivers/scsi/isci/request.c
@@ -53,6 +53,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <scsi/scsi_cmnd.h>
 #include "isci.h"
 #include "task.h"
 #include "request.h"
@@ -264,6 +265,142 @@ static void scu_ssp_reqeust_construct_task_context(
 	task_context->response_iu_lower = lower_32_bits(dma_addr);
 }
 
+static u8 scu_bg_blk_size(struct scsi_device *sdp)
+{
+	switch (sdp->sector_size) {
+		case 512:
+			return 0;
+		case 1024:
+			return 1;
+		case 4096:
+			return 3;
+		default:
+			return 0xff;
+	}
+}
+
+static u32 scu_dif_bytes(u32 len, u32 sector_size)
+{
+	return (len >> ilog2(sector_size)) * 8;
+}
+
+static void scu_ssp_ireq_dif_insert(struct isci_request *ireq, u8 type, u8 op)
+{
+	struct scu_task_context *tc = ireq->tc;
+	struct scsi_cmnd *scmd = ireq->ttype_ptr.io_task_ptr->uldd_task;
+	u8 blk_sz = scu_bg_blk_size(scmd->device);
+
+	tc->block_guard_enable = 1;
+	tc->blk_prot_en = 1;
+	tc->blk_sz = blk_sz;
+	/* DIF write insert */
+	tc->blk_prot_func = 0x2;
+
+	tc->transfer_length_bytes += scu_dif_bytes(tc->transfer_length_bytes,
+						   scmd->device->sector_size);
+
+	/* always init to 0, used by hw */
+	tc->interm_crc_val = 0;
+
+	tc->init_crc_seed = 0;
+	tc->app_tag_verify = 0;
+	tc->app_tag_gen = 0;
+	tc->ref_tag_seed_verify = 0;
+
+	/* always init to same as bg_blk_sz */
+	tc->UD_bytes_immed_val = scmd->device->sector_size;
+
+	tc->reserved_DC_0 = 0;
+
+	/* always init to 8 */
+	tc->DIF_bytes_immed_val = 8;
+
+	tc->reserved_DC_1 = 0;
+	tc->bgc_blk_sz = scmd->device->sector_size;
+	tc->reserved_E0_0 = 0;
+	tc->app_tag_gen_mask = 0;
+
+	/** setup block guard control **/
+	tc->bgctl = 0;
+
+	/* DIF write insert */
+	tc->bgctl_f.op = 0x2;
+
+	tc->app_tag_verify_mask = 0;
+
+	/* must init to 0 for hw */
+	tc->blk_guard_err = 0;
+
+	tc->reserved_E8_0 = 0;
+
+	if ((type & SCSI_PROT_DIF_TYPE1) || (type & SCSI_PROT_DIF_TYPE2)) {
+		tc->ref_tag_seed_gen = scsi_get_lba(scmd) & 0xffffffff;
+	} else if (type & SCSI_PROT_DIF_TYPE3)
+		tc->ref_tag_seed_gen = 0;
+
+}
+
+static void scu_ssp_ireq_dif_strip(struct isci_request *ireq, u8 type, u8 op)
+{
+	struct scu_task_context *tc = ireq->tc;
+	struct scsi_cmnd *scmd = ireq->ttype_ptr.io_task_ptr->uldd_task;
+	u8 blk_sz = scu_bg_blk_size(scmd->device);
+
+	tc->block_guard_enable = 1;
+	tc->blk_prot_en = 1;
+	tc->blk_sz = blk_sz;
+	/* DIF read strip */
+	tc->blk_prot_func = 0x1;
+
+	tc->transfer_length_bytes += scu_dif_bytes(tc->transfer_length_bytes,
+						   scmd->device->sector_size);
+
+	/* always init to 0, used by hw */
+	tc->interm_crc_val = 0;
+
+	tc->init_crc_seed = 0;
+	tc->app_tag_verify = 0;
+	tc->app_tag_gen = 0;
+
+	if ((type & SCSI_PROT_DIF_TYPE1) || (type & SCSI_PROT_DIF_TYPE2)) {
+		tc->ref_tag_seed_verify = scsi_get_lba(scmd) & 0xffffffff;
+	} else if (type & SCSI_PROT_DIF_TYPE3)
+		tc->ref_tag_seed_verify = 0;
+
+	/* always init to same as bg_blk_sz */
+	tc->UD_bytes_immed_val = scmd->device->sector_size;
+
+	tc->reserved_DC_0 = 0;
+
+	/* always init to 8 */
+	tc->DIF_bytes_immed_val = 8;
+
+	tc->reserved_DC_1 = 0;
+	tc->bgc_blk_sz = scmd->device->sector_size;
+	tc->reserved_E0_0 = 0;
+	tc->app_tag_gen_mask = 0;
+
+	/** setup block guard control **/
+	tc->bgctl = 0;
+
+	/* DIF read strip */
+	tc->bgctl_f.crc_verify = 1;
+	tc->bgctl_f.op = 0x1;
+	if ((type & SCSI_PROT_DIF_TYPE1) || (type & SCSI_PROT_DIF_TYPE2)) {
+		tc->bgctl_f.ref_tag_chk = 1;
+		tc->bgctl_f.app_f_detect = 1;
+	} else if (type & SCSI_PROT_DIF_TYPE3)
+		tc->bgctl_f.app_ref_f_detect = 1;
+
+	tc->app_tag_verify_mask = 0;
+
+	/* must init to 0 for hw */
+	tc->blk_guard_err = 0;
+
+	tc->reserved_E8_0 = 0;
+	tc->ref_tag_seed_gen = 0;
+}
+
 /**
  * This method is will fill in the SCU Task Context for a SSP IO request.
  * @sci_req:
@@ -274,6 +411,10 @@ static void scu_ssp_io_request_construct_task_context(struct isci_request *ireq,
 						      u32 len)
 {
 	struct scu_task_context *task_context = ireq->tc;
+	struct sas_task *sas_task = ireq->ttype_ptr.io_task_ptr;
+	struct scsi_cmnd *scmd = sas_task->uldd_task;
+	u8 prot_type = scsi_get_prot_type(scmd);
+	u8 prot_op = scsi_get_prot_op(scmd);
 
 	scu_ssp_reqeust_construct_task_context(ireq, task_context);
 
@@ -296,6 +437,13 @@ static void scu_ssp_io_request_construct_task_context(struct isci_request *ireq,
 
 	if (task_context->transfer_length_bytes > 0)
 		sci_request_build_sgl(ireq);
+
+	if (prot_type != SCSI_PROT_DIF_TYPE0) {
+		if (prot_op == SCSI_PROT_READ_STRIP)
+			scu_ssp_ireq_dif_strip(ireq, prot_type, prot_op);
+		else if (prot_op == SCSI_PROT_WRITE_INSERT)
+			scu_ssp_ireq_dif_insert(ireq, prot_type, prot_op);
+	}
 }
 
 /**
diff --git a/drivers/scsi/isci/scu_task_context.h b/drivers/scsi/isci/scu_task_context.h
index 7df87d9..869a979 100644
--- a/drivers/scsi/isci/scu_task_context.h
+++ b/drivers/scsi/isci/scu_task_context.h
@@ -866,9 +866,9 @@ struct scu_task_context {
 	struct transport_snapshot snapshot; /* read only set to 0 */
 
 	/* OFFSET 0x5C */
-	u32 block_protection_enable:1;
-	u32 block_size:2;
-	u32 block_protection_function:2;
+	u32 blk_prot_en:1;
+	u32 blk_sz:2;
+	u32 blk_prot_func:2;
 	u32 reserved_5C_0:9;
 	u32 active_sgl_element:2;  /* read only set to 0 */
 	u32 sgl_exhausted:1;  /* read only set to 0 */
@@ -896,33 +896,56 @@ struct scu_task_context {
 	u32 reserved_C4_CC[3];
 
 	/* OFFSET 0xD0 */
-	u32 intermediate_crc_value:16;
-	u32 initial_crc_seed:16;
+	u32 interm_crc_val:16;
+	u32 init_crc_seed:16;
 
 	/* OFFSET 0xD4 */
-	u32 application_tag_for_verify:16;
-	u32 application_tag_for_generate:16;
+	u32 app_tag_verify:16;
+	u32 app_tag_gen:16;
 
 	/* OFFSET 0xD8 */
-	u32 reference_tag_seed_for_verify_function;
+	u32 ref_tag_seed_verify;
 
 	/* OFFSET 0xDC */
-	u32 reserved_DC;
+	u32 UD_bytes_immed_val:13;
+	u32 reserved_DC_0:3;
+	u32 DIF_bytes_immed_val:4;
+	u32 reserved_DC_1:12;
 
 	/* OFFSET 0xE0 */
-	u32 reserved_E0_0:16;
-	u32 application_tag_mask_for_generate:16;
+	u32 bgc_blk_sz:13;
+	u32 reserved_E0_0:3;
+	u32 app_tag_gen_mask:16;
 
 	/* OFFSET 0xE4 */
-	u32 block_protection_control:16;
-	u32 application_tag_mask_for_verify:16;
+	union {
+		u16 bgctl;
+		struct {
+			u16 crc_verify:1;
+			u16 app_tag_chk:1;
+			u16 ref_tag_chk:1;
+			u16 op:2;
+			u16 legacy:1;
+			u16 invert_crc_seed:1;
+			u16 ref_tag_gen:1;
+			u16 fixed_ref_tag:1;
+			u16 invert_crc:1;
+			u16 app_ref_f_detect:1;
+			u16 uninit_dif_check_err:1;
+			u16 uninit_dif_bypass:1;
+			u16 app_f_detect:1;
+			u16 reserved_0:2;
+		} bgctl_f;
+	};
+
+	u16 app_tag_verify_mask;
 
 	/* OFFSET 0xE8 */
-	u32 block_protection_error:8;
+	u32 blk_guard_err:8;
 	u32 reserved_E8_0:24;
 
 	/* OFFSET 0xEC */
-	u32 reference_tag_seed_for_verify;
+	u32 ref_tag_seed_gen;
 
 	/* OFFSET 0xF0 */
 	u32 intermediate_crc_valid_snapshot:16;
@@ -937,6 +960,6 @@ struct scu_task_context {
 	/* OFFSET 0xFC */
 	u32 reference_tag_seed_for_generate_function_snapshot;
 
-};
+} __packed;
 
 #endif /* _SCU_TASK_CONTEXT_H_ */