gallium: add user_stride parameter to pipe_context::transfer_map

Allow callers to prescribe a desired stride for a transfer. Drivers
are free to ignore this new parameter.

There is no new capability because it's unclear how strict requirements
on this feature should be expressed.

33 files changed, 53 insertions, 12 deletions

diff --git a/src/gallium/auxiliary/util/u_inlines.h b/src/gallium/auxiliary/util/u_inlines.h
index a71580cc53..0f4e30b5f1 100644
--- a/src/gallium/auxiliary/util/u_inlines.h
+++ b/src/gallium/auxiliary/util/u_inlines.h
@@ -308,7 +308,7 @@ pipe_buffer_map_range(struct pipe_context *pipe,
 
    u_box_1d(offset, length, &box);
 
-   map = pipe->transfer_map(pipe, buffer, 0, access, &box, transfer);
+   map = pipe->transfer_map(pipe, buffer, 0, access, &box, 0, transfer);
    if (!map) {
       return NULL;
    }
@@ -445,7 +445,7 @@ pipe_transfer_map_box(struct pipe_context *context,
                       const struct pipe_box *box,
                       struct pipe_transfer **out_transfer)
 {
-   return context->transfer_map(context, resource, level, usage, box,
+   return context->transfer_map(context, resource, level, usage, box, 0,
                                 out_transfer);
 }
 
@@ -469,7 +469,7 @@ pipe_transfer_map(struct pipe_context *context,
                                 resource,
                                 level,
                                 access,
-                                &box, transfer);
+                                &box, 0, transfer);
 }
 
 
@@ -492,7 +492,7 @@ pipe_transfer_map_3d(struct pipe_context *context,
                                 resource,
                                 level,
                                 access,
-                                &box, transfer);
+                                &box, 0, transfer);
 }
 
 static inline void
diff --git a/src/gallium/auxiliary/util/u_threaded_context.c b/src/gallium/auxiliary/util/u_threaded_context.c
index ffa824744e..35efefcc83 100644
--- a/src/gallium/auxiliary/util/u_threaded_context.c
+++ b/src/gallium/auxiliary/util/u_threaded_context.c
@@ -1436,6 +1436,7 @@ static void *
 tc_transfer_map(struct pipe_context *_pipe,
                 struct pipe_resource *resource, unsigned level,
                 unsigned usage, const struct pipe_box *box,
+                unsigned user_stride,
                 struct pipe_transfer **transfer)
 {
    struct threaded_context *tc = threaded_context(_pipe);
@@ -1480,7 +1481,7 @@ tc_transfer_map(struct pipe_context *_pipe,
                       usage & PIPE_TRANSFER_READ ? "  read" : "  ??");
 
    return pipe->transfer_map(pipe, tres->latest ? tres->latest : resource,
-                             level, usage, box, transfer);
+                             level, usage, box, user_stride, transfer);
 }
 
 struct tc_transfer_flush_region {
@@ -1641,7 +1642,7 @@ tc_buffer_subdata(struct pipe_context *_pipe,
 
       u_box_1d(offset, size, &box);
 
-      map = tc_transfer_map(_pipe, resource, 0, usage, &box, &transfer);
+      map = tc_transfer_map(_pipe, resource, 0, usage, &box, 0, &transfer);
       if (map) {
          memcpy(map, data, size);
          tc_transfer_unmap(_pipe, transfer);
diff --git a/src/gallium/auxiliary/util/u_transfer.c b/src/gallium/auxiliary/util/u_transfer.c
index 0e0c4cc91c..5f07ea067f 100644
--- a/src/gallium/auxiliary/util/u_transfer.c
+++ b/src/gallium/auxiliary/util/u_transfer.c
@@ -132,11 +132,12 @@ void *u_transfer_map_vtbl(struct pipe_context *context,
                           unsigned level,
                           unsigned usage,
                           const struct pipe_box *box,
+                          unsigned user_stride,
                           struct pipe_transfer **transfer)
 {
    struct u_resource *ur = u_resource(resource);
    return ur->vtbl->transfer_map(context, resource, level, usage, box,
-                                 transfer);
+                                 user_stride, transfer);
 }
 
 void u_transfer_flush_region_vtbl( struct pipe_context *pipe,
diff --git a/src/gallium/auxiliary/util/u_transfer.h b/src/gallium/auxiliary/util/u_transfer.h
index 14084983da..9f1fcb626f 100644
--- a/src/gallium/auxiliary/util/u_transfer.h
+++ b/src/gallium/auxiliary/util/u_transfer.h
@@ -58,6 +58,7 @@ struct u_resource_vtbl {
                          unsigned level,
                          unsigned usage,
                          const struct pipe_box *,
+                         unsigned user_stride,
                          struct pipe_transfer **);
 
 
@@ -90,6 +91,7 @@ void *u_transfer_map_vtbl(struct pipe_context *context,
                           unsigned level,
                           unsigned usage,
                           const struct pipe_box *box,
+                          unsigned user_stride,
                           struct pipe_transfer **transfer);
 
 void u_transfer_flush_region_vtbl( struct pipe_context *pipe,
diff --git a/src/gallium/auxiliary/util/u_transfer_helper.c b/src/gallium/auxiliary/util/u_transfer_helper.c
index f69015af51..b5ad30c522 100644
--- a/src/gallium/auxiliary/util/u_transfer_helper.c
+++ b/src/gallium/auxiliary/util/u_transfer_helper.c
@@ -224,6 +224,7 @@ u_transfer_helper_transfer_map(struct pipe_context *pctx,
                                struct pipe_resource *prsc,
                                unsigned level, unsigned usage,
                                const struct pipe_box *box,
+                               unsigned user_stride,
                                struct pipe_transfer **pptrans)
 {
    struct u_transfer_helper *helper = pctx->screen->transfer_helper;
diff --git a/src/gallium/auxiliary/util/u_transfer_helper.h b/src/gallium/auxiliary/util/u_transfer_helper.h
index b13a1ec06c..351efa894d 100644
--- a/src/gallium/auxiliary/util/u_transfer_helper.h
+++ b/src/gallium/auxiliary/util/u_transfer_helper.h
@@ -109,6 +109,7 @@ void *u_transfer_helper_transfer_map(struct pipe_context *pctx,
                                      unsigned level,
                                      unsigned usage,
                                      const struct pipe_box *box,
+                                     unsigned user_stride,
                                      struct pipe_transfer **pptrans);
 
 
diff --git a/src/gallium/drivers/ddebug/dd_draw.c b/src/gallium/drivers/ddebug/dd_draw.c
index c404ea0607..aa98f357b9 100644
--- a/src/gallium/drivers/ddebug/dd_draw.c
+++ b/src/gallium/drivers/ddebug/dd_draw.c
@@ -1480,6 +1480,7 @@ static void *
 dd_context_transfer_map(struct pipe_context *_pipe,
                         struct pipe_resource *resource, unsigned level,
                         unsigned usage, const struct pipe_box *box,
+                        unsigned user_stride,
                         struct pipe_transfer **transfer)
 {
    struct dd_context *dctx = dd_context(_pipe);
@@ -1492,7 +1493,7 @@ dd_context_transfer_map(struct pipe_context *_pipe,
 
       dd_before_draw(dctx, record);
    }
-   void *ptr = pipe->transfer_map(pipe, resource, level, usage, box, transfer);
+   void *ptr = pipe->transfer_map(pipe, resource, level, usage, box, user_stride, transfer);
    if (record) {
       record->call.info.transfer_map.transfer_ptr = *transfer;
       record->call.info.transfer_map.ptr = ptr;
diff --git a/src/gallium/drivers/etnaviv/etnaviv_transfer.c b/src/gallium/drivers/etnaviv/etnaviv_transfer.c
index 30ae3bfc39..8d079ad4e2 100644
--- a/src/gallium/drivers/etnaviv/etnaviv_transfer.c
+++ b/src/gallium/drivers/etnaviv/etnaviv_transfer.c
@@ -138,6 +138,7 @@ etna_transfer_map(struct pipe_context *pctx, struct pipe_resource *prsc,
                   unsigned level,
                   unsigned usage,
                   const struct pipe_box *box,
+                  unsigned user_stride,
                   struct pipe_transfer **out_transfer)
 {
    struct etna_context *ctx = etna_context(pctx);
diff --git a/src/gallium/drivers/i915/i915_resource_buffer.c b/src/gallium/drivers/i915/i915_resource_buffer.c
index 2572fc40b2..88a3181ee6 100644
--- a/src/gallium/drivers/i915/i915_resource_buffer.c
+++ b/src/gallium/drivers/i915/i915_resource_buffer.c
@@ -66,6 +66,7 @@ i915_buffer_transfer_map(struct pipe_context *pipe,
                          unsigned level,
                          unsigned usage,
                          const struct pipe_box *box,
+                         unsigned user_stride,
                          struct pipe_transfer **ptransfer)
 {
    struct i915_context *i915 = i915_context(pipe);
diff --git a/src/gallium/drivers/i915/i915_resource_texture.c b/src/gallium/drivers/i915/i915_resource_texture.c
index 4ade04f223..fbf8362427 100644
--- a/src/gallium/drivers/i915/i915_resource_texture.c
+++ b/src/gallium/drivers/i915/i915_resource_texture.c
@@ -717,6 +717,7 @@ i915_texture_transfer_map(struct pipe_context *pipe,
                           unsigned level,
                           unsigned usage,
                           const struct pipe_box *box,
+                          unsigned user_stride,
                           struct pipe_transfer **ptransfer)
 {
    struct i915_context *i915 = i915_context(pipe);
diff --git a/src/gallium/drivers/llvmpipe/lp_texture.c b/src/gallium/drivers/llvmpipe/lp_texture.c
index 162c74ad7d..5424781d8e 100644
--- a/src/gallium/drivers/llvmpipe/lp_texture.c
+++ b/src/gallium/drivers/llvmpipe/lp_texture.c
@@ -510,6 +510,7 @@ llvmpipe_transfer_map( struct pipe_context *pipe,
                        unsigned level,
                        unsigned usage,
                        const struct pipe_box *box,
+                       unsigned user_stride,
                        struct pipe_transfer **transfer )
 {
    struct llvmpipe_context *llvmpipe = llvmpipe_context(pipe);
diff --git a/src/gallium/drivers/noop/noop_pipe.c b/src/gallium/drivers/noop/noop_pipe.c
index d1e795dab1..cc74fcbd5d 100644
--- a/src/gallium/drivers/noop/noop_pipe.c
+++ b/src/gallium/drivers/noop/noop_pipe.c
@@ -174,6 +174,7 @@ static void *noop_transfer_map(struct pipe_context *pipe,
                                unsigned level,
                                enum pipe_transfer_usage usage,
                                const struct pipe_box *box,
+                               unsigned user_stride,
                                struct pipe_transfer **ptransfer)
 {
    struct pipe_transfer *transfer;
diff --git a/src/gallium/drivers/nouveau/nouveau_buffer.c b/src/gallium/drivers/nouveau/nouveau_buffer.c
index 2c604419ce..c5be45cadb 100644
--- a/src/gallium/drivers/nouveau/nouveau_buffer.c
+++ b/src/gallium/drivers/nouveau/nouveau_buffer.c
@@ -377,6 +377,7 @@ nouveau_buffer_transfer_map(struct pipe_context *pipe,
                             struct pipe_resource *resource,
                             unsigned level, unsigned usage,
                             const struct pipe_box *box,
+                            unsigned user_stride,
                             struct pipe_transfer **ptransfer)
 {
    struct nouveau_context *nv = nouveau_context(pipe);
diff --git a/src/gallium/drivers/nouveau/nv30/nv30_miptree.c b/src/gallium/drivers/nouveau/nv30/nv30_miptree.c
index 165b8f29b4..b2a3f5626a 100644
--- a/src/gallium/drivers/nouveau/nv30/nv30_miptree.c
+++ b/src/gallium/drivers/nouveau/nv30/nv30_miptree.c
@@ -261,6 +261,7 @@ static void *
 nv30_miptree_transfer_map(struct pipe_context *pipe, struct pipe_resource *pt,
                           unsigned level, unsigned usage,
                           const struct pipe_box *box,
+                          unsigned user_stride,
                           struct pipe_transfer **ptransfer)
 {
    struct nv30_context *nv30 = nv30_context(pipe);
diff --git a/src/gallium/drivers/nouveau/nv50/nv50_transfer.c b/src/gallium/drivers/nouveau/nv50/nv50_transfer.c
index 8209f1f1e8..debc01e8fb 100644
--- a/src/gallium/drivers/nouveau/nv50/nv50_transfer.c
+++ b/src/gallium/drivers/nouveau/nv50/nv50_transfer.c
@@ -247,6 +247,7 @@ nv50_miptree_transfer_map(struct pipe_context *pctx,
                           unsigned level,
                           unsigned usage,
                           const struct pipe_box *box,
+                          unsigned user_stride,
                           struct pipe_transfer **ptransfer)
 {
    struct nv50_screen *screen = nv50_screen(pctx->screen);
diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_transfer.c b/src/gallium/drivers/nouveau/nvc0/nvc0_transfer.c
index 225b894717..69a031a46f 100644
--- a/src/gallium/drivers/nouveau/nvc0/nvc0_transfer.c
+++ b/src/gallium/drivers/nouveau/nvc0/nvc0_transfer.c
@@ -372,6 +372,7 @@ nvc0_miptree_transfer_map(struct pipe_context *pctx,
                           unsigned level,
                           unsigned usage,
                           const struct pipe_box *box,
+                          unsigned user_stride,
                           struct pipe_transfer **ptransfer)
 {
    struct nvc0_context *nvc0 = nvc0_context(pctx);
diff --git a/src/gallium/drivers/r300/r300_screen_buffer.c b/src/gallium/drivers/r300/r300_screen_buffer.c
index 4af1c46856..5b761fdd5b 100644
--- a/src/gallium/drivers/r300/r300_screen_buffer.c
+++ b/src/gallium/drivers/r300/r300_screen_buffer.c
@@ -69,6 +69,7 @@ r300_buffer_transfer_map( struct pipe_context *context,
                           unsigned level,
                           unsigned usage,
                           const struct pipe_box *box,
+                          unsigned user_stride,
                           struct pipe_transfer **ptransfer )
 {
     struct r300_context *r300 = r300_context(context);
diff --git a/src/gallium/drivers/r300/r300_transfer.c b/src/gallium/drivers/r300/r300_transfer.c
index 9d00f4d937..35361b5b7b 100644
--- a/src/gallium/drivers/r300/r300_transfer.c
+++ b/src/gallium/drivers/r300/r300_transfer.c
@@ -105,6 +105,7 @@ r300_texture_transfer_map(struct pipe_context *ctx,
                           unsigned level,
                           unsigned usage,
                           const struct pipe_box *box,
+                          unsigned user_stride,
                           struct pipe_transfer **transfer)
 {
     struct r300_context *r300 = r300_context(ctx);
diff --git a/src/gallium/drivers/r300/r300_transfer.h b/src/gallium/drivers/r300/r300_transfer.h
index 45477ae6d0..54cc5aa704 100644
--- a/src/gallium/drivers/r300/r300_transfer.h
+++ b/src/gallium/drivers/r300/r300_transfer.h
@@ -34,6 +34,7 @@ r300_texture_transfer_map(struct pipe_context *ctx,
                           unsigned level,
                           unsigned usage,
                           const struct pipe_box *box,
+                          unsigned user_stride,
                           struct pipe_transfer **transfer);
 
 void
diff --git a/src/gallium/drivers/r600/evergreen_compute.c b/src/gallium/drivers/r600/evergreen_compute.c
index 6925d9e585..091f4939d9 100644
--- a/src/gallium/drivers/r600/evergreen_compute.c
+++ b/src/gallium/drivers/r600/evergreen_compute.c
@@ -1175,6 +1175,7 @@ static void *r600_compute_global_transfer_map(struct pipe_context *ctx,
 					      unsigned level,
 					      unsigned usage,
 					      const struct pipe_box *box,
+                                              unsigned user_stride,
 					      struct pipe_transfer **ptransfer)
 {
 	struct r600_context *rctx = (struct r600_context*)ctx;
diff --git a/src/gallium/drivers/r600/r600_buffer_common.c b/src/gallium/drivers/r600/r600_buffer_common.c
index 501b96fa0b..b09e0fa797 100644
--- a/src/gallium/drivers/r600/r600_buffer_common.c
+++ b/src/gallium/drivers/r600/r600_buffer_common.c
@@ -352,6 +352,7 @@ static void *r600_buffer_transfer_map(struct pipe_context *ctx,
                                       unsigned level,
                                       unsigned usage,
                                       const struct pipe_box *box,
+                                      unsigned user_stride,
                                       struct pipe_transfer **ptransfer)
 {
 	struct r600_common_context *rctx = (struct r600_common_context*)ctx;
@@ -558,7 +559,7 @@ void r600_buffer_subdata(struct pipe_context *ctx,
 				       PIPE_TRANSFER_WRITE |
 				       PIPE_TRANSFER_DISCARD_RANGE |
 				       usage,
-				       &box, &transfer);
+				       &box, 0, &transfer);
 	if (!map)
 		return;
 
diff --git a/src/gallium/drivers/r600/r600_texture.c b/src/gallium/drivers/r600/r600_texture.c
index 03cdcd22ee..f310853299 100644
--- a/src/gallium/drivers/r600/r600_texture.c
+++ b/src/gallium/drivers/r600/r600_texture.c
@@ -1274,6 +1274,7 @@ static void *r600_texture_transfer_map(struct pipe_context *ctx,
 				       unsigned level,
 				       unsigned usage,
 				       const struct pipe_box *box,
+                                       unsigned user_stride,
 				       struct pipe_transfer **ptransfer)
 {
 	struct r600_common_context *rctx = (struct r600_common_context*)ctx;
diff --git a/src/gallium/drivers/radeon/r600_buffer_common.c b/src/gallium/drivers/radeon/r600_buffer_common.c
index aca536d7fd..6c55182c8f 100644
--- a/src/gallium/drivers/radeon/r600_buffer_common.c
+++ b/src/gallium/drivers/radeon/r600_buffer_common.c
@@ -346,6 +346,7 @@ static void *r600_buffer_transfer_map(struct pipe_context *ctx,
                                       unsigned level,
                                       unsigned usage,
                                       const struct pipe_box *box,
+                                      unsigned user_stride,
                                       struct pipe_transfer **ptransfer)
 {
 	struct r600_common_context *rctx = (struct r600_common_context*)ctx;
@@ -566,7 +567,7 @@ static void si_buffer_subdata(struct pipe_context *ctx,
 				       PIPE_TRANSFER_WRITE |
 				       PIPE_TRANSFER_DISCARD_RANGE |
 				       usage,
-				       &box, &transfer);
+				       &box, 0, &transfer);
 	if (!map)
 		return;
 
diff --git a/src/gallium/drivers/radeon/r600_texture.c b/src/gallium/drivers/radeon/r600_texture.c
index 34b3ab0cde..ecc70280b4 100644
--- a/src/gallium/drivers/radeon/r600_texture.c
+++ b/src/gallium/drivers/radeon/r600_texture.c
@@ -1629,6 +1629,7 @@ static void *r600_texture_transfer_map(struct pipe_context *ctx,
 				       unsigned level,
 				       unsigned usage,
 				       const struct pipe_box *box,
+				       unsigned user_stride,
 				       struct pipe_transfer **ptransfer)
 {
 	struct r600_common_context *rctx = (struct r600_common_context*)ctx;
diff --git a/src/gallium/drivers/rbug/rbug_context.c b/src/gallium/drivers/rbug/rbug_context.c
index e1f3c4f284..a03f4a79b4 100644
--- a/src/gallium/drivers/rbug/rbug_context.c
+++ b/src/gallium/drivers/rbug/rbug_context.c
@@ -1072,6 +1072,7 @@ rbug_context_transfer_map(struct pipe_context *_context,
                           unsigned level,
                           unsigned usage,
                           const struct pipe_box *box,
+                          unsigned user_stride,
                           struct pipe_transfer **transfer)
 {
    struct rbug_context *rb_pipe = rbug_context(_context);
@@ -1086,7 +1087,9 @@ rbug_context_transfer_map(struct pipe_context *_context,
                                resource,
                                level,
                                usage,
-                               box, &result);
+                               box,
+                               user_stride,
+                               &result);
    mtx_unlock(&rb_pipe->call_mutex);
 
    *transfer = rbug_transfer_create(rb_pipe, rb_resource, result);
diff --git a/src/gallium/drivers/softpipe/sp_texture.c b/src/gallium/drivers/softpipe/sp_texture.c
index ea5e2c64b8..d099576ca9 100644
--- a/src/gallium/drivers/softpipe/sp_texture.c
+++ b/src/gallium/drivers/softpipe/sp_texture.c
@@ -357,6 +357,7 @@ softpipe_transfer_map(struct pipe_context *pipe,
                       unsigned level,
                       unsigned usage,
                       const struct pipe_box *box,
+                      unsigned user_stride,
                       struct pipe_transfer **transfer)
 {
    struct sw_winsys *winsys = softpipe_screen(pipe->screen)->winsys;
diff --git a/src/gallium/drivers/svga/svga_resource_buffer.c b/src/gallium/drivers/svga/svga_resource_buffer.c
index e9d31de616..dc706cccce 100644
--- a/src/gallium/drivers/svga/svga_resource_buffer.c
+++ b/src/gallium/drivers/svga/svga_resource_buffer.c
@@ -70,6 +70,7 @@ svga_buffer_transfer_map(struct pipe_context *pipe,
                          unsigned level,
                          unsigned usage,
                          const struct pipe_box *box,
+                         unsigned user_stride,
                          struct pipe_transfer **ptransfer)
 {
    struct svga_context *svga = svga_context(pipe);
diff --git a/src/gallium/drivers/svga/svga_resource_texture.c b/src/gallium/drivers/svga/svga_resource_texture.c
index 71b8ebe7d4..5a0141316b 100644
--- a/src/gallium/drivers/svga/svga_resource_texture.c
+++ b/src/gallium/drivers/svga/svga_resource_texture.c
@@ -540,6 +540,7 @@ svga_texture_transfer_map(struct pipe_context *pipe,
                           unsigned level,
                           unsigned usage,
                           const struct pipe_box *box,
+                          unsigned user_stride,
                           struct pipe_transfer **ptransfer)
 {
    struct svga_context *svga = svga_context(pipe);
diff --git a/src/gallium/drivers/trace/tr_context.c b/src/gallium/drivers/trace/tr_context.c
index 6d918d42a3..ff8b556b59 100644
--- a/src/gallium/drivers/trace/tr_context.c
+++ b/src/gallium/drivers/trace/tr_context.c
@@ -1375,6 +1375,7 @@ trace_context_transfer_map(struct pipe_context *_context,
                            unsigned level,
                            unsigned usage,
                            const struct pipe_box *box,
+                           unsigned user_stride,
                            struct pipe_transfer **transfer)
 {
    struct trace_context *tr_context = trace_context(_context);
@@ -1387,7 +1388,7 @@ trace_context_transfer_map(struct pipe_context *_context,
     * to texture/buffer_subdata and ignore read transfers.
     */
 
-   map = context->transfer_map(context, resource, level, usage, box, &result);
+   map = context->transfer_map(context, resource, level, usage, box, user_stride, &result);
    if (!map)
       return NULL;
 
diff --git a/src/gallium/drivers/vc4/vc4_resource.c b/src/gallium/drivers/vc4/vc4_resource.c
index cdcbcc917e..cb604cba75 100644
--- a/src/gallium/drivers/vc4/vc4_resource.c
+++ b/src/gallium/drivers/vc4/vc4_resource.c
@@ -150,6 +150,7 @@ vc4_resource_transfer_map(struct pipe_context *pctx,
                           struct pipe_resource *prsc,
                           unsigned level, unsigned usage,
                           const struct pipe_box *box,
+                          unsigned user_stride,
                           struct pipe_transfer **pptrans)
 {
         struct vc4_context *vc4 = vc4_context(pctx);
diff --git a/src/gallium/drivers/virgl/virgl_buffer.c b/src/gallium/drivers/virgl/virgl_buffer.c
index 2e63aebc72..d6af398b10 100644
--- a/src/gallium/drivers/virgl/virgl_buffer.c
+++ b/src/gallium/drivers/virgl/virgl_buffer.c
@@ -43,6 +43,7 @@ static void *virgl_buffer_transfer_map(struct pipe_context *ctx,
                                        unsigned level,
                                        unsigned usage,
                                        const struct pipe_box *box,
+                                       unsigned user_stride,
                                        struct pipe_transfer **transfer)
 {
    struct virgl_context *vctx = virgl_context(ctx);
diff --git a/src/gallium/drivers/virgl/virgl_texture.c b/src/gallium/drivers/virgl/virgl_texture.c
index 150a5ebd8c..903418f97a 100644
--- a/src/gallium/drivers/virgl/virgl_texture.c
+++ b/src/gallium/drivers/virgl/virgl_texture.c
@@ -124,6 +124,7 @@ static void *virgl_texture_transfer_map(struct pipe_context *ctx,
                                         unsigned level,
                                         unsigned usage,
                                         const struct pipe_box *box,
+                                        unsigned user_stride,
                                         struct pipe_transfer **transfer)
 {
    struct virgl_context *vctx = virgl_context(ctx);
diff --git a/src/gallium/include/pipe/p_context.h b/src/gallium/include/pipe/p_context.h
index b74e649219..2c7e1e7799 100644
--- a/src/gallium/include/pipe/p_context.h
+++ b/src/gallium/include/pipe/p_context.h
@@ -565,12 +565,19 @@ struct pipe_context {
     * out_transfer will contain the transfer object that must be passed
     * to all the other transfer functions. It also contains useful
     * information (like texture strides).
+    *
+    * If \p user_stride is non-zero, the driver should attempt to provide
+    * a transfer with stride == user_stride. However, the resulting stride
+    * may be different, e.g. if user_stride is not sufficiently aligned.
+    * The map may also fail if user_stride is insufficiently aligned or too
+    * large, and the behavior is undefined if user_stride is too small.
     */
    void *(*transfer_map)(struct pipe_context *,
                          struct pipe_resource *resource,
                          unsigned level,
                          unsigned usage,  /* a combination of PIPE_TRANSFER_x */
                          const struct pipe_box *,
+                         unsigned user_stride,
                          struct pipe_transfer **out_transfer);
 
    /* If transfer was created with WRITE|FLUSH_EXPLICIT, only the