drm/vkms: Use dma-buf mapping from shadow-plane state for composing

Store the shadow-buffer mapping's address in struct vkms_composer and
use the value when composing the output. It's the same value as stored
in the GEM SHMEM BO, but frees the composer code from its dependency
on GEM SHMEM.

Using struct dma_buf_map is how framebuffer access is supposed to be.
The long-term plan is to perform all framebuffer access via struct
dma_buf_map and avoid the details of accessing I/O and system memory.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Melissa Wen <melissa.srw@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210705074633.9425-5-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c
index 3ade0df173d25efb4aef6d5b232f00ea1470c99c..ead8fff81f30362ca7b3c05a96d5f4f686628188 100644 (file)
--- a/drivers/gpu/drm/vkms/vkms_composer.c
+++ b/drivers/gpu/drm/vkms/vkms_composer.c
@@ -6,7 +6,6 @@
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_gem_framebuffer_helper.h>
-#include <drm/drm_gem_shmem_helper.h>
 #include <drm/drm_vblank.h>
 
 #include "vkms_drv.h"
@@ -154,24 +153,21 @@ static void compose_plane(struct vkms_composer *primary_composer,
                          struct vkms_composer *plane_composer,
                          void *vaddr_out)
 {
-       struct drm_gem_object *plane_obj;
-       struct drm_gem_shmem_object *plane_shmem_obj;
        struct drm_framebuffer *fb = &plane_composer->fb;
+       void *vaddr;
        void (*pixel_blend)(const u8 *p_src, u8 *p_dst);
 
-       plane_obj = drm_gem_fb_get_obj(&plane_composer->fb, 0);
-       plane_shmem_obj = to_drm_gem_shmem_obj(plane_obj);
-
-       if (WARN_ON(!plane_shmem_obj->vaddr))
+       if (WARN_ON(dma_buf_map_is_null(&primary_composer->map[0])))
                return;
 
+       vaddr = plane_composer->map[0].vaddr;
+
        if (fb->format->format == DRM_FORMAT_ARGB8888)
                pixel_blend = &alpha_blend;
        else
                pixel_blend = &x_blend;
 
-       blend(vaddr_out, plane_shmem_obj->vaddr, primary_composer,
-             plane_composer, pixel_blend);
+       blend(vaddr_out, vaddr, primary_composer, plane_composer, pixel_blend);
 }
 
 static int compose_active_planes(void **vaddr_out,
@@ -180,21 +176,23 @@ static int compose_active_planes(void **vaddr_out,
 {
        struct drm_framebuffer *fb = &primary_composer->fb;
        struct drm_gem_object *gem_obj = drm_gem_fb_get_obj(fb, 0);
-       struct drm_gem_shmem_object *shmem_obj = to_drm_gem_shmem_obj(gem_obj);
+       const void *vaddr;
        int i;
 
        if (!*vaddr_out) {
-               *vaddr_out = kzalloc(shmem_obj->base.size, GFP_KERNEL);
+               *vaddr_out = kzalloc(gem_obj->size, GFP_KERNEL);
                if (!*vaddr_out) {
                        DRM_ERROR("Cannot allocate memory for output frame.");
                        return -ENOMEM;
                }
        }
 
-       if (WARN_ON(!shmem_obj->vaddr))
+       if (WARN_ON(dma_buf_map_is_null(&primary_composer->map[0])))
                return -EINVAL;
 
-       memcpy(*vaddr_out, shmem_obj->vaddr, shmem_obj->base.size);
+       vaddr = primary_composer->map[0].vaddr;
+
+       memcpy(*vaddr_out, vaddr, gem_obj->size);
 
        /* If there are other planes besides primary, we consider the active
         * planes should be in z-order and compose them associatively:

diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
index 7a76dccd7316bdfe3185454f1f0a430bd48ef388..8c731b6dcba711101cfbcda9c85ec07d5ee0ca3b 100644 (file)
--- a/drivers/gpu/drm/vkms/vkms_drv.h
+++ b/drivers/gpu/drm/vkms/vkms_drv.h
@@ -23,6 +23,7 @@
 struct vkms_composer {
        struct drm_framebuffer fb;
        struct drm_rect src, dst;
+       struct dma_buf_map map[4];
        unsigned int offset;
        unsigned int pitch;
        unsigned int cpp;

diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
index 8fbbd148163df3c9cdad709f4db5ae70897ee685..8a56fbf572b0c4f59c3c27b901dea4eac734328e 100644 (file)
--- a/drivers/gpu/drm/vkms/vkms_plane.c
+++ b/drivers/gpu/drm/vkms/vkms_plane.c
@@ -97,6 +97,7 @@ static void vkms_plane_atomic_update(struct drm_plane *plane,
        struct drm_plane_state *new_state = drm_atomic_get_new_plane_state(state,
                                                                           plane);
        struct vkms_plane_state *vkms_plane_state;
+       struct drm_shadow_plane_state *shadow_plane_state;
        struct drm_framebuffer *fb = new_state->fb;
        struct vkms_composer *composer;
 
@@ -104,11 +105,13 @@ static void vkms_plane_atomic_update(struct drm_plane *plane,
                return;
 
        vkms_plane_state = to_vkms_plane_state(new_state);
+       shadow_plane_state = &vkms_plane_state->base;
 
        composer = vkms_plane_state->composer;
        memcpy(&composer->src, &new_state->src, sizeof(struct drm_rect));
        memcpy(&composer->dst, &new_state->dst, sizeof(struct drm_rect));
        memcpy(&composer->fb, fb, sizeof(struct drm_framebuffer));
+       memcpy(&composer->map, &shadow_plane_state->map, sizeof(composer->map));
        drm_framebuffer_get(&composer->fb);
        composer->offset = fb->offsets[0];
        composer->pitch = fb->pitches[0];