isci: Remove SCIC_SWAP_DWORD()

Use Linux native swab32() call instead of SCIC_SWAP_DWORD().

We need to swab() because the hardware munges the data into a
"big-endian dword" stream which is byte-swapped from the sas definition
regardless of host endian.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

5 files changed, 60 insertions, 91 deletions

diff --git a/drivers/scsi/isci/core/sci_util.c b/drivers/scsi/isci/core/sci_util.c
index ebf0ed919a9..0c75d14240a 100644
--- a/drivers/scsi/isci/core/sci_util.c
+++ b/drivers/scsi/isci/core/sci_util.c
@@ -57,19 +57,6 @@
 #include "sci_util.h"
 #include "sci_environment.h"
 
-void scic_word_copy_with_swap(
-	u32 *destination,
-	u32 *source,
-	u32 word_count)
-{
-	while (word_count--) {
-		*destination = SCIC_SWAP_DWORD(*source);
-
-		source++;
-		destination++;
-	}
-}
-
 void *scic_request_get_virt_addr(struct scic_sds_request *sci_req, dma_addr_t phys_addr)
 {
 	struct isci_request *ireq = sci_req->ireq;
diff --git a/drivers/scsi/isci/core/sci_util.h b/drivers/scsi/isci/core/sci_util.h
index b6f43e27c61..4e9c3189cf9 100644
--- a/drivers/scsi/isci/core/sci_util.h
+++ b/drivers/scsi/isci/core/sci_util.h
@@ -56,22 +56,8 @@
 #ifndef _SCI_UTIL_H_
 #define _SCI_UTIL_H_
 
-#include <linux/string.h>
 #include "scic_sds_request.h"
 
-/**
- * SCIC_SWAP_DWORD() -
- *
- * Normal byte swap macro
- */
-#define SCIC_SWAP_DWORD(x) \
-	(\
-		(((x) >> 24) & 0x000000FF) \
-		| (((x) >>  8) & 0x0000FF00) \
-		| (((x) <<  8) & 0x00FF0000) \
-		| (((x) << 24) & 0xFF000000) \
-	)
-
 #define SCIC_BUILD_DWORD(char_buffer) \
 	(\
 		((char_buffer)[0] << 24) \
@@ -87,17 +73,23 @@
 	((physical_addr) = (addr_lower) | ((u64)addr_upper) << 32)
 
 /**
- * scic_word_copy_with_swap() - Copy the data from source to destination and
- *    swap the bytes during the copy.
- * @destination: This parameter specifies the destination address to which the
- *    data is to be copied.
- * @source: This parameter specifies the source address from which data is to
- *    be copied.
- * @word_count: This parameter specifies the number of 32-bit words to copy and
- *    byte swap.
+ * sci_swab32_cpy - convert between scsi and scu-hardware byte format
+ * @dest: receive the 4-byte endian swapped version of src
+ * @src: word aligned source buffer
  *
+ * scu hardware handles SSP/SMP control, response, and unidentified
+ * frames in "big endian dword" order.  Regardless of host endian this
+ * is always a swab32()-per-dword conversion of the standard definition,
+ * i.e. single byte fields swapped and multi-byte fields in little-
+ * endian
  */
-void scic_word_copy_with_swap(u32 *destination, u32 *source, u32 word_count);
+static inline void sci_swab32_cpy(void *_dest, void *_src, ssize_t word_cnt)
+{
+	u32 *dest = _dest, *src = _src;
+
+	while (--word_cnt >= 0)
+		dest[word_cnt] = swab32(src[word_cnt]);
+}
 
 void *scic_request_get_virt_addr(struct scic_sds_request *sds_request,
 				 dma_addr_t phys_addr);
diff --git a/drivers/scsi/isci/core/scic_sds_phy.c b/drivers/scsi/isci/core/scic_sds_phy.c
index b9d6fc7e8ae..18dc14a8f0b 100644
--- a/drivers/scsi/isci/core/scic_sds_phy.c
+++ b/drivers/scsi/isci/core/scic_sds_phy.c
@@ -1098,7 +1098,7 @@ static enum sci_status scic_sds_phy_starting_substate_await_iaf_uf_frame_handler
 {
 	enum sci_status result;
 	u32 *frame_words;
-	struct sas_identify_frame *identify_frame;
+	struct sas_identify_frame iaf;
 	struct isci_phy *iphy = sci_phy->iphy;
 
 	result = scic_sds_unsolicited_frame_control_get_header(
@@ -1106,38 +1106,29 @@ static enum sci_status scic_sds_phy_starting_substate_await_iaf_uf_frame_handler
 		frame_index,
 		(void **)&frame_words);
 
-	if (result != SCI_SUCCESS) {
+	if (result != SCI_SUCCESS)
 		return result;
-	}
-
-	frame_words[0] = SCIC_SWAP_DWORD(frame_words[0]);
-	identify_frame = (struct sas_identify_frame *)frame_words;
 
-	if (identify_frame->frame_type == 0) {
+	sci_swab32_cpy(&iaf, frame_words, sizeof(iaf) / sizeof(u32));
+	if (iaf.frame_type == 0) {
 		u32 state;
 
-		/* Byte swap the rest of the frame so we can make
-		 * a copy of the buffer
-		 */
-		frame_words[1] = SCIC_SWAP_DWORD(frame_words[1]);
-		frame_words[2] = SCIC_SWAP_DWORD(frame_words[2]);
-		frame_words[3] = SCIC_SWAP_DWORD(frame_words[3]);
-		frame_words[4] = SCIC_SWAP_DWORD(frame_words[4]);
-		frame_words[5] = SCIC_SWAP_DWORD(frame_words[5]);
-
-		memcpy(&iphy->frame_rcvd.iaf, identify_frame, sizeof(*identify_frame));
-
-		if (identify_frame->smp_tport) {
-			/* We got the IAF for an expander PHY go to the final state since
-			 * there are no power requirements for expander phys.
+		memcpy(&iphy->frame_rcvd.iaf, &iaf, sizeof(iaf));
+		if (iaf.smp_tport) {
+			/* We got the IAF for an expander PHY go to the final
+			 * state since there are no power requirements for
+			 * expander phys.
 			 */
 			state = SCIC_SDS_PHY_STARTING_SUBSTATE_FINAL;
 		} else {
-			/* We got the IAF we can now go to the await spinup semaphore state */
+			/* We got the IAF we can now go to the await spinup
+			 * semaphore state
+			 */
 			state = SCIC_SDS_PHY_STARTING_SUBSTATE_AWAIT_SAS_POWER;
 		}
-		sci_base_state_machine_change_state(&sci_phy->starting_substate_machine,
-						    state);
+		sci_base_state_machine_change_state(
+				&sci_phy->starting_substate_machine,
+				state);
 		result = SCI_SUCCESS;
 	} else
 		dev_warn(sciphy_to_dev(sci_phy),
@@ -1146,7 +1137,6 @@ static enum sci_status scic_sds_phy_starting_substate_await_iaf_uf_frame_handler
 			__func__,
 			frame_index);
 
-	/* Regardless of the result release this frame since we are done with it */
 	scic_sds_controller_release_frame(scic_sds_phy_get_controller(sci_phy),
 					  frame_index);
 
diff --git a/drivers/scsi/isci/core/scic_sds_request.c b/drivers/scsi/isci/core/scic_sds_request.c
index 8eb3c7e59ec..e9c69d451f4 100644
--- a/drivers/scsi/isci/core/scic_sds_request.c
+++ b/drivers/scsi/isci/core/scic_sds_request.c
@@ -362,10 +362,8 @@ static void scic_sds_io_request_build_ssp_command_iu(struct scic_sds_request *sc
 	cmd_iu->task_attr = task->ssp_task.task_attr;
 	cmd_iu->_r_c = 0;
 
-	scic_word_copy_with_swap(
-		(u32 *)(&cmd_iu->cdb),
-		(u32 *)task->ssp_task.cdb,
-		sizeof(task->ssp_task.cdb) / sizeof(u32));
+	sci_swab32_cpy(&cmd_iu->cdb, task->ssp_task.cdb,
+		       sizeof(task->ssp_task.cdb) / sizeof(u32));
 }
 
 static void scic_sds_task_request_build_ssp_task_iu(struct scic_sds_request *sci_req)
@@ -1120,10 +1118,11 @@ scic_sds_request_started_state_tc_completion_handler(
 		 * completed early.
 		 */
 		struct ssp_response_iu *resp = sci_req->response_buffer;
-		scic_word_copy_with_swap(
-			sci_req->response_buffer,
-			sci_req->response_buffer,
-			SSP_RESP_IU_MAX_SIZE / sizeof(u32));
+		ssize_t word_cnt = SSP_RESP_IU_MAX_SIZE / sizeof(u32);
+
+		sci_swab32_cpy(sci_req->response_buffer,
+			       sci_req->response_buffer,
+			       word_cnt);
 
 		if (resp->status == 0) {
 			scic_sds_request_set_status(
@@ -1140,16 +1139,18 @@ scic_sds_request_started_state_tc_completion_handler(
 	break;
 
 	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_CHECK_RESPONSE):
-		scic_word_copy_with_swap(
-			sci_req->response_buffer,
-			sci_req->response_buffer,
-			SSP_RESP_IU_MAX_SIZE / sizeof(u32));
+	{
+		ssize_t word_cnt = SSP_RESP_IU_MAX_SIZE / sizeof(u32);
 
-		scic_sds_request_set_status(
-			sci_req,
-			SCU_TASK_DONE_CHECK_RESPONSE,
-			SCI_FAILURE_IO_RESPONSE_VALID);
+		sci_swab32_cpy(sci_req->response_buffer,
+			       sci_req->response_buffer,
+			       word_cnt);
+
+		scic_sds_request_set_status(sci_req,
+					    SCU_TASK_DONE_CHECK_RESPONSE,
+					    SCI_FAILURE_IO_RESPONSE_VALID);
 		break;
+	}
 
 	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_RESP_LEN_ERR):
 		/*
@@ -1273,15 +1274,15 @@ scic_sds_request_started_state_frame_handler(struct scic_sds_request *sci_req,
 
 	if (frame_header->frame_type == SCI_SAS_RESPONSE_FRAME) {
 		struct ssp_response_iu *resp_iu;
+		ssize_t word_cnt = SSP_RESP_IU_MAX_SIZE / sizeof(u32);
 
 		status = scic_sds_unsolicited_frame_control_get_buffer(
 			&(scic_sds_request_get_controller(sci_req)->uf_control),
 			frame_index,
 			(void **)&resp_iu);
 
-		scic_word_copy_with_swap(sci_req->response_buffer,
-					 (u32 *)resp_iu,
-					 SSP_RESP_IU_MAX_SIZE);
+		sci_swab32_cpy(sci_req->response_buffer,
+			       resp_iu, word_cnt);
 
 		resp_iu = sci_req->response_buffer;
 
diff --git a/drivers/scsi/isci/core/scic_sds_smp_request.c b/drivers/scsi/isci/core/scic_sds_smp_request.c
index e6cfcbba9f9..bca51a72ee8 100644
--- a/drivers/scsi/isci/core/scic_sds_smp_request.c
+++ b/drivers/scsi/isci/core/scic_sds_smp_request.c
@@ -164,11 +164,11 @@ scu_smp_request_construct_task_context(struct scic_sds_request *sci_req,
 	struct scic_sds_remote_device *sci_dev;
 	struct scic_sds_port *sci_port;
 	struct scu_task_context *task_context;
+	ssize_t word_cnt = sizeof(struct smp_req) / sizeof(u32);
 
 	/* byte swap the smp request. */
-	scic_word_copy_with_swap(sci_req->command_buffer,
-				 (u32 *)smp_req,
-				 sizeof(struct smp_req) / sizeof(u32));
+	sci_swab32_cpy(sci_req->command_buffer, smp_req,
+		       word_cnt);
 
 	task_context = scic_sds_request_get_task_context(sci_req);
 
@@ -295,6 +295,7 @@ scic_sds_smp_request_await_response_frame_handler(
 	void *frame_header;
 	struct smp_resp *rsp_hdr;
 	u8 *usr_smp_buf = sci_req->response_buffer;
+	ssize_t word_cnt = SMP_RESP_HDR_SZ / sizeof(u32);
 
 	status = scic_sds_unsolicited_frame_control_get_header(
 		&(scic_sds_request_get_controller(sci_req)->uf_control),
@@ -302,9 +303,7 @@ scic_sds_smp_request_await_response_frame_handler(
 		&frame_header);
 
 	/* byte swap the header. */
-	scic_word_copy_with_swap((u32 *)usr_smp_buf,
-				 frame_header,
-				 SMP_RESP_HDR_SZ / sizeof(u32));
+	sci_swab32_cpy(usr_smp_buf, frame_header, word_cnt);
 
 	rsp_hdr = (struct smp_resp *)usr_smp_buf;
 
@@ -316,11 +315,11 @@ scic_sds_smp_request_await_response_frame_handler(
 			frame_index,
 			&smp_resp);
 
-		scic_word_copy_with_swap(
-			(u32 *)(usr_smp_buf + SMP_RESP_HDR_SZ),
-			smp_resp,
-			(sizeof(struct smp_req) - SMP_RESP_HDR_SZ) /
-			sizeof(u32));
+		word_cnt = (sizeof(struct smp_req) - SMP_RESP_HDR_SZ) /
+			sizeof(u32);
+
+		sci_swab32_cpy(usr_smp_buf + SMP_RESP_HDR_SZ,
+			       smp_resp, word_cnt);
 
 		scic_sds_request_set_status(
 			sci_req, SCU_TASK_DONE_GOOD, SCI_SUCCESS);