scsi: storvsc: Set the tablesize based on the information given by the host

Set the tablesize based on the information given by the host.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Tested-by: Long Li <longli@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

1 files changed, 64 insertions, 25 deletions

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 4156e297ea64..d9dad90344d5 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -351,7 +351,10 @@ struct storvsc_cmd_request {
         /* Synchronize the request/response if needed */
         struct completion wait_event;
 
-        struct hv_multipage_buffer data_buffer;
+        struct vmbus_channel_packet_multipage_buffer mpb;
+        struct vmbus_packet_mpb_array *payload;
+        u32 payload_sz;
+
         struct vstor_packet vstor_packet;
 };
 
@@ -1103,6 +1106,8 @@ static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
         struct Scsi_Host *host;
         struct storvsc_device *stor_dev;
         struct hv_device *dev = host_dev->dev;
+        u32 payload_sz = cmd_request->payload_sz;
+        void *payload = cmd_request->payload;
 
         stor_dev = get_in_stor_device(dev);
         host = stor_dev->host;
@@ -1132,10 +1137,14 @@ static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
                                          sense_hdr.ascq);
 
         scsi_set_resid(scmnd,
-                cmd_request->data_buffer.len -
+                cmd_request->payload->range.len -
                 vm_srb->data_transfer_length);
 
         scmnd->scsi_done(scmnd);
+
+        if (payload_sz >
+                sizeof(struct vmbus_channel_packet_multipage_buffer))
+                kfree(payload);
 }
 
 static void storvsc_on_io_completion(struct hv_device *device,
@@ -1337,7 +1346,7 @@ static int storvsc_dev_remove(struct hv_device *device)
 }
 
 static int storvsc_do_io(struct hv_device *device,
-                              struct storvsc_cmd_request *request)
+                         struct storvsc_cmd_request *request)
 {
         struct storvsc_device *stor_device;
         struct vstor_packet *vstor_packet;
@@ -1369,13 +1378,14 @@ static int storvsc_do_io(struct hv_device *device,
 
 
         vstor_packet->vm_srb.data_transfer_length =
-        request->data_buffer.len;
+        request->payload->range.len;
 
         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
 
-        if (request->data_buffer.len) {
-                ret = vmbus_sendpacket_multipagebuffer(outgoing_channel,
-                                &request->data_buffer,
+        if (request->payload->range.len) {
+
+                ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
+                                request->payload, request->payload_sz,
                                 vstor_packet,
                                 (sizeof(struct vstor_packet) -
                                 vmscsi_size_delta),
@@ -1549,6 +1559,9 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
         unsigned int sg_count = 0;
         struct vmscsi_request *vm_srb;
         struct scatterlist *cur_sgl;
+        struct vmbus_packet_mpb_array  *payload;
+        u32 payload_sz;
+        u32 length;
 
         if (vmstor_current_major <= VMSTOR_WIN8_MAJOR) {
                 /*
@@ -1602,48 +1615,71 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
 
         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
 
-        cmd_request->data_buffer.len = scsi_bufflen(scmnd);
-        if (scsi_sg_count(scmnd)) {
-                sgl = (struct scatterlist *)scsi_sglist(scmnd);
-                sg_count = scsi_sg_count(scmnd);
+        sgl = (struct scatterlist *)scsi_sglist(scmnd);
+        sg_count = scsi_sg_count(scmnd);
 
+        length = scsi_bufflen(scmnd);
+        payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
+        payload_sz = sizeof(cmd_request->mpb);
+
+        if (sg_count) {
                 /* check if we need to bounce the sgl */
                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
                         cmd_request->bounce_sgl =
-                                create_bounce_buffer(sgl, scsi_sg_count(scmnd),
-                                                     scsi_bufflen(scmnd),
+                                create_bounce_buffer(sgl, sg_count,
+                                                     length,
                                                      vm_srb->data_in);
                         if (!cmd_request->bounce_sgl)
                                 return SCSI_MLQUEUE_HOST_BUSY;
 
                         cmd_request->bounce_sgl_count =
-                                ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
-                                        PAGE_SHIFT;
+                                ALIGN(length, PAGE_SIZE) >> PAGE_SHIFT;
 
                         if (vm_srb->data_in == WRITE_TYPE)
                                 copy_to_bounce_buffer(sgl,
-                                        cmd_request->bounce_sgl,
-                                        scsi_sg_count(scmnd));
+                                        cmd_request->bounce_sgl, sg_count);
 
                         sgl = cmd_request->bounce_sgl;
                         sg_count = cmd_request->bounce_sgl_count;
                 }
 
-                cmd_request->data_buffer.offset = sgl[0].offset;
+
+                if (sg_count > MAX_PAGE_BUFFER_COUNT) {
+
+                        payload_sz = (sg_count * sizeof(void *) +
+                                      sizeof(struct vmbus_packet_mpb_array));
+                        payload = kmalloc(payload_sz, GFP_ATOMIC);
+                        if (!payload) {
+                                if (cmd_request->bounce_sgl_count)
+                                        destroy_bounce_buffer(
+                                        cmd_request->bounce_sgl,
+                                        cmd_request->bounce_sgl_count);
+
+                                        return SCSI_MLQUEUE_DEVICE_BUSY;
+                        }
+                }
+
+                payload->range.len = length;
+                payload->range.offset = sgl[0].offset;
+
                 cur_sgl = sgl;
                 for (i = 0; i < sg_count; i++) {
-                        cmd_request->data_buffer.pfn_array[i] =
+                        payload->range.pfn_array[i] =
                                 page_to_pfn(sg_page((cur_sgl)));
                         cur_sgl = sg_next(cur_sgl);
                 }
 
         } else if (scsi_sglist(scmnd)) {
-                cmd_request->data_buffer.offset =
+                payload->range.len = length;
+                payload->range.offset =
                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
-                cmd_request->data_buffer.pfn_array[0] =
+                payload->range.pfn_array[0] =
                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
         }
 
+        cmd_request->payload = payload;
+        cmd_request->payload_sz = payload_sz;
+
         /* Invokes the vsc to start an IO */
         ret = storvsc_do_io(dev, cmd_request);
 
@@ -1672,10 +1708,7 @@ static struct scsi_host_template scsi_driver = {
         .slave_configure =      storvsc_device_configure,
         .cmd_per_lun =          255,
         .this_id =              -1,
-        /* no use setting to 0 since ll_blk_rw reset it to 1 */
-        /* currently 32 */
-        .sg_tablesize =         MAX_MULTIPAGE_BUFFER_COUNT,
-        .use_clustering =       DISABLE_CLUSTERING,
+        .use_clustering =       ENABLE_CLUSTERING,
         /* Make sure we dont get a sg segment crosses a page boundary */
         .dma_boundary =         PAGE_SIZE-1,
         .no_write_same =        1,
@@ -1812,6 +1845,12 @@ static int storvsc_probe(struct hv_device *device,
         /* max cmd length */
         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
 
+        /*
+         * set the table size based on the info we got
+         * from the host.
+         */
+        host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
+
         /* Register the HBA and start the scsi bus scan */
         ret = scsi_add_host(host, &device->device);
         if (ret != 0)