[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>

4 files changed, 21 insertions, 35 deletions

diff --git a/drivers/scsi/isci/isci.h b/drivers/scsi/isci/isci.h
index d1de63312e7f..8efeb6b08321 100644
--- a/drivers/scsi/isci/isci.h
+++ b/drivers/scsi/isci/isci.h
@@ -97,7 +97,7 @@
 #define SCU_MAX_COMPLETION_QUEUE_SHIFT    (ilog2(SCU_MAX_COMPLETION_QUEUE_ENTRIES))
 
 #define SCU_ABSOLUTE_MAX_UNSOLICITED_FRAMES (4096)
-#define SCU_UNSOLICITED_FRAME_BUFFER_SIZE   (1024)
+#define SCU_UNSOLICITED_FRAME_BUFFER_SIZE   (1024U)
 #define SCU_INVALID_FRAME_INDEX             (0xFFFF)
 
 #define SCU_IO_REQUEST_MAX_SGE_SIZE         (0x00FFFFFF)
diff --git a/drivers/scsi/isci/request.c b/drivers/scsi/isci/request.c
index b5d3a8c4d329..225b196800a2 100644
--- a/drivers/scsi/isci/request.c
+++ b/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);
-
-                /* byte swap the header. */
-                word_cnt = SMP_RESP_HDR_SZ / sizeof(u32);
-                sci_swab32_cpy(rsp_hdr, frame_header, word_cnt);
+                                                         frame_index,
+                                                         &frame_header);
+                kaddr = kmap_atomic(sg_page(sg), KM_IRQ0);
+                rsp = kaddr + sg->offset;
+                sci_swab32_cpy(rsp, frame_header, 1);
 
-                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
diff --git a/drivers/scsi/isci/request.h b/drivers/scsi/isci/request.h
index 7a1d5a9778eb..58d70b6606ef 100644
--- a/drivers/scsi/isci/request.h
+++ b/drivers/scsi/isci/request.h
@@ -174,9 +174,6 @@ struct isci_request {
                         };
                 } ssp;
                 struct {
-                        struct smp_resp rsp;
-                } smp;
-                struct {
                         struct isci_stp_request req;
                         struct host_to_dev_fis cmd;
                         struct dev_to_host_fis rsp;
diff --git a/drivers/scsi/isci/sas.h b/drivers/scsi/isci/sas.h
index 462b15174d3f..dc26b4aea99e 100644
--- a/drivers/scsi/isci/sas.h
+++ b/drivers/scsi/isci/sas.h
@@ -204,8 +204,6 @@ struct smp_req {
         u8 req_data[0];
 }  __packed;
 
-#define SMP_RESP_HDR_SZ 4
-
 /*
  * struct sci_sas_address - This structure depicts how a SAS address is
  *    represented by SCI.