scsi: smartpqi: Refactor scatterlist code

Factor out code common to all scatter-gather list building to prepare for
new AIO functionality. AIO (Accelerated I/O) requests go directly to disk

No functional changes.

Link: https://lore.kernel.org/r/161549372147.25025.9706613054649682229.stgit@brunhilda
Reviewed-by: Scott Benesh <scott.benesh@microchip.com>
Reviewed-by: Mike McGowen <mike.mcgowen@microchip.com>
Reviewed-by: Scott Teel <scott.teel@microchip.com>
Reviewed-by: Kevin Barnett <kevin.barnett@microchip.com>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Don Brace <don.brace@microchip.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c
index c895d32952c18b88157472afc05f3082846cff28..0eb8d4744e3d225231e326429d91abd4b40894c7 100644 (file)
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -4857,16 +4857,52 @@ static inline void pqi_set_sg_descriptor(
        put_unaligned_le32(0, &sg_descriptor->flags);
 }
 
+static unsigned int pqi_build_sg_list(struct pqi_sg_descriptor *sg_descriptor,
+       struct scatterlist *sg, int sg_count, struct pqi_io_request *io_request,
+       int max_sg_per_iu, bool *chained)
+{
+       int i;
+       unsigned int num_sg_in_iu;
+
+       *chained = false;
+       i = 0;
+       num_sg_in_iu = 0;
+       max_sg_per_iu--;        /* Subtract 1 to leave room for chain marker. */
+
+       while (1) {
+               pqi_set_sg_descriptor(sg_descriptor, sg);
+               if (!*chained)
+                       num_sg_in_iu++;
+               i++;
+               if (i == sg_count)
+                       break;
+               sg_descriptor++;
+               if (i == max_sg_per_iu) {
+                       put_unaligned_le64((u64)io_request->sg_chain_buffer_dma_handle,
+                               &sg_descriptor->address);
+                       put_unaligned_le32((sg_count - num_sg_in_iu) * sizeof(*sg_descriptor),
+                               &sg_descriptor->length);
+                       put_unaligned_le32(CISS_SG_CHAIN, &sg_descriptor->flags);
+                       *chained = true;
+                       num_sg_in_iu++;
+                       sg_descriptor = io_request->sg_chain_buffer;
+               }
+               sg = sg_next(sg);
+       }
+
+       put_unaligned_le32(CISS_SG_LAST, &sg_descriptor->flags);
+
+       return num_sg_in_iu;
+}
+
 static int pqi_build_raid_sg_list(struct pqi_ctrl_info *ctrl_info,
        struct pqi_raid_path_request *request, struct scsi_cmnd *scmd,
        struct pqi_io_request *io_request)
 {
-       int i;
        u16 iu_length;
        int sg_count;
        bool chained;
        unsigned int num_sg_in_iu;
-       unsigned int max_sg_per_iu;
        struct scatterlist *sg;
        struct pqi_sg_descriptor *sg_descriptor;
 
@@ -4882,36 +4918,10 @@ static int pqi_build_raid_sg_list(struct pqi_ctrl_info *ctrl_info,
 
        sg = scsi_sglist(scmd);
        sg_descriptor = request->sg_descriptors;
-       max_sg_per_iu = ctrl_info->max_sg_per_iu - 1;
-       chained = false;
-       num_sg_in_iu = 0;
-       i = 0;
 
-       while (1) {
-               pqi_set_sg_descriptor(sg_descriptor, sg);
-               if (!chained)
-                       num_sg_in_iu++;
-               i++;
-               if (i == sg_count)
-                       break;
-               sg_descriptor++;
-               if (i == max_sg_per_iu) {
-                       put_unaligned_le64(
-                               (u64)io_request->sg_chain_buffer_dma_handle,
-                               &sg_descriptor->address);
-                       put_unaligned_le32((sg_count - num_sg_in_iu)
-                               * sizeof(*sg_descriptor),
-                               &sg_descriptor->length);
-                       put_unaligned_le32(CISS_SG_CHAIN,
-                               &sg_descriptor->flags);
-                       chained = true;
-                       num_sg_in_iu++;
-                       sg_descriptor = io_request->sg_chain_buffer;
-               }
-               sg = sg_next(sg);
-       }
+       num_sg_in_iu = pqi_build_sg_list(sg_descriptor, sg, sg_count, io_request,
+               ctrl_info->max_sg_per_iu, &chained);
 
-       put_unaligned_le32(CISS_SG_LAST, &sg_descriptor->flags);
        request->partial = chained;
        iu_length += num_sg_in_iu * sizeof(*sg_descriptor);
 
@@ -4925,12 +4935,10 @@ static int pqi_build_aio_sg_list(struct pqi_ctrl_info *ctrl_info,
        struct pqi_aio_path_request *request, struct scsi_cmnd *scmd,
        struct pqi_io_request *io_request)
 {
-       int i;
        u16 iu_length;
        int sg_count;
        bool chained;
        unsigned int num_sg_in_iu;
-       unsigned int max_sg_per_iu;
        struct scatterlist *sg;
        struct pqi_sg_descriptor *sg_descriptor;
 
@@ -4947,35 +4955,10 @@ static int pqi_build_aio_sg_list(struct pqi_ctrl_info *ctrl_info,
 
        sg = scsi_sglist(scmd);
        sg_descriptor = request->sg_descriptors;
-       max_sg_per_iu = ctrl_info->max_sg_per_iu - 1;
-       chained = false;
-       i = 0;
 
-       while (1) {
-               pqi_set_sg_descriptor(sg_descriptor, sg);
-               if (!chained)
-                       num_sg_in_iu++;
-               i++;
-               if (i == sg_count)
-                       break;
-               sg_descriptor++;
-               if (i == max_sg_per_iu) {
-                       put_unaligned_le64(
-                               (u64)io_request->sg_chain_buffer_dma_handle,
-                               &sg_descriptor->address);
-                       put_unaligned_le32((sg_count - num_sg_in_iu)
-                               * sizeof(*sg_descriptor),
-                               &sg_descriptor->length);
-                       put_unaligned_le32(CISS_SG_CHAIN,
-                               &sg_descriptor->flags);
-                       chained = true;
-                       num_sg_in_iu++;
-                       sg_descriptor = io_request->sg_chain_buffer;
-               }
-               sg = sg_next(sg);
-       }
+       num_sg_in_iu = pqi_build_sg_list(sg_descriptor, sg, sg_count, io_request,
+               ctrl_info->max_sg_per_iu, &chained);
 
-       put_unaligned_le32(CISS_SG_LAST, &sg_descriptor->flags);
        request->partial = chained;
        iu_length += num_sg_in_iu * sizeof(*sg_descriptor);