hyperv: Add support for physically discontinuous receive buffer

This will allow us to use bigger receive buffer, and prevent allocation failure
due to fragmented memory.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 6 deletions

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index cea623c36ae2..69ea36f07b4d 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -209,7 +209,6 @@ static int create_gpadl_header(void *kbuffer, u32 size,
 {
         int i;
         int pagecount;
-        unsigned long long pfn;
         struct vmbus_channel_gpadl_header *gpadl_header;
         struct vmbus_channel_gpadl_body *gpadl_body;
         struct vmbus_channel_msginfo *msgheader;
@@ -219,7 +218,6 @@ static int create_gpadl_header(void *kbuffer, u32 size,
         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
 
         pagecount = size >> PAGE_SHIFT;
-        pfn = virt_to_phys(kbuffer) >> PAGE_SHIFT;
 
         /* do we need a gpadl body msg */
         pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
@@ -248,7 +246,8 @@ static int create_gpadl_header(void *kbuffer, u32 size,
                 gpadl_header->range[0].byte_offset = 0;
                 gpadl_header->range[0].byte_count = size;
                 for (i = 0; i < pfncount; i++)
-                        gpadl_header->range[0].pfn_array[i] = pfn+i;
+                        gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
+                                kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
                 *msginfo = msgheader;
                 *messagecount = 1;
 
@@ -301,7 +300,9 @@ static int create_gpadl_header(void *kbuffer, u32 size,
                          * so the hypervisor gurantees that this is ok.
                          */
                         for (i = 0; i < pfncurr; i++)
-                                gpadl_body->pfn[i] = pfn + pfnsum + i;
+                                gpadl_body->pfn[i] = slow_virt_to_phys(
+                                        kbuffer + PAGE_SIZE * (pfnsum + i)) >>
+                                        PAGE_SHIFT;
 
                         /* add to msg header */
                         list_add_tail(&msgbody->msglistentry,
@@ -327,7 +328,8 @@ static int create_gpadl_header(void *kbuffer, u32 size,
                 gpadl_header->range[0].byte_offset = 0;
                 gpadl_header->range[0].byte_count = size;
                 for (i = 0; i < pagecount; i++)
-                        gpadl_header->range[0].pfn_array[i] = pfn+i;
+                        gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
+                                kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 
                 *msginfo = msgheader;
                 *messagecount = 1;
@@ -344,7 +346,7 @@ nomem:
  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
  *
  * @channel: a channel
- * @kbuffer: from kmalloc
+ * @kbuffer: from kmalloc or vmalloc
  * @size: page-size multiple
  * @gpadl_handle: some funky thing
  */