[SCSI] isci: fix support for large smp requests

Kill the local smp response buffer.

Besides being unnecessary, it is too small (currently truncates
responses to 60 bytes).  The mid-layer will have already allocated a
sufficiently sized buffer, just kmap and copy into it directly.

Cc: <stable@kernel.org>
Reported-by: Derick Marks <derick.w.marks@intel.com>
Tested-by: Derick Marks <derick.w.marks@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/isci/request.c

@@ -1490,29 +1490,30 @@ sci_io_request_frame_handler(struct isci_request *ireq,
 		return SCI_SUCCESS;
 
 	case SCI_REQ_SMP_WAIT_RESP: {
-		struct smp_resp *rsp_hdr = &ireq->smp.rsp;
-		void *frame_header;
+		struct sas_task *task = isci_request_access_task(ireq);
+		struct scatterlist *sg = &task->smp_task.smp_resp;
+		void *frame_header, *kaddr;
+		u8 *rsp;
 
 		sci_unsolicited_frame_control_get_header(&ihost->uf_control,
-							      frame_index,
-							      &frame_header);
+							 frame_index,
+							 &frame_header);
+		kaddr = kmap_atomic(sg_page(sg), KM_IRQ0);
+		rsp = kaddr + sg->offset;
+		sci_swab32_cpy(rsp, frame_header, 1);
 
-		/* byte swap the header. */
-		word_cnt = SMP_RESP_HDR_SZ / sizeof(u32);
-		sci_swab32_cpy(rsp_hdr, frame_header, word_cnt);
-
-		if (rsp_hdr->frame_type == SMP_RESPONSE) {
+		if (rsp[0] == SMP_RESPONSE) {
 			void *smp_resp;
 
 			sci_unsolicited_frame_control_get_buffer(&ihost->uf_control,
-								      frame_index,
-								      &smp_resp);
+								 frame_index,
+								 &smp_resp);
 
-			word_cnt = (sizeof(struct smp_resp) - SMP_RESP_HDR_SZ) /
-				sizeof(u32);
-
-			sci_swab32_cpy(((u8 *) rsp_hdr) + SMP_RESP_HDR_SZ,
-				       smp_resp, word_cnt);
+			word_cnt = (sg->length/4)-1;
+			if (word_cnt > 0)
+				word_cnt = min_t(unsigned int, word_cnt,
+						 SCU_UNSOLICITED_FRAME_BUFFER_SIZE/4);
+			sci_swab32_cpy(rsp + 4, smp_resp, word_cnt);
 
 			ireq->scu_status = SCU_TASK_DONE_GOOD;
 			ireq->sci_status = SCI_SUCCESS;
@@ -1528,12 +1529,13 @@ sci_io_request_frame_handler(struct isci_request *ireq,
 				__func__,
 				ireq,
 				frame_index,
-				rsp_hdr->frame_type);
+				rsp[0]);
 
 			ireq->scu_status = SCU_TASK_DONE_SMP_FRM_TYPE_ERR;
 			ireq->sci_status = SCI_FAILURE_CONTROLLER_SPECIFIC_IO_ERR;
 			sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
 		}
+		kunmap_atomic(kaddr, KM_IRQ0);
 
 		sci_controller_release_frame(ihost, frame_index);
 
@@ -2603,18 +2605,7 @@ static void isci_request_io_request_complete(struct isci_host *ihost,
 			status   = SAM_STAT_GOOD;
 			set_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
 
-			if (task->task_proto == SAS_PROTOCOL_SMP) {
-				void *rsp = &request->smp.rsp;
-
-				dev_dbg(&ihost->pdev->dev,
-					"%s: SMP protocol completion\n",
-					__func__);
-
-				sg_copy_from_buffer(
-					&task->smp_task.smp_resp, 1,
-					rsp, sizeof(struct smp_resp));
-			} else if (completion_status
-				   == SCI_IO_SUCCESS_IO_DONE_EARLY) {
+			if (completion_status == SCI_IO_SUCCESS_IO_DONE_EARLY) {
 
 				/* This was an SSP / STP / SATA transfer.
 				 * There is a possibility that less data than