[PATCH] drm/ast: Support both SHMEM helper and VRAM helper

Thomas Zimmermann tzimmermann at suse.de
Wed Mar 5 09:04:52 UTC 2025


Hi

Am 04.03.25 um 12:55 schrieb Huacai Chen:
> On Tue, Mar 4, 2025 at 5:39 PM Thomas Zimmermann <tzimmermann at suse.de> wrote:
>> Hi
>>
>> Am 04.03.25 um 10:19 schrieb Huacai Chen:
>>> On Tue, Mar 4, 2025 at 4:41 PM Thomas Zimmermann <tzimmermann at suse.de> wrote:
>>>> Hi
>>>>
>>>> Am 04.03.25 um 07:33 schrieb Huacai Chen:
>>>>> Commit f2fa5a99ca81ce105653 ("drm/ast: Convert ast to SHMEM") converts
>>>>> ast from VRAM helper to SHMEM helper. The convertion makesast support
>>>>> higher display resolutions, but the performance decreases significantly
>>>>> on platforms which don't support writecombine (fallback to uncached).
>>>>>
>>>>> This patch implements both SHMEM helper and VRAM helper for ast driver
>>>>> at the same time. A module parameter ast.shmem is added, 1 means SHMEM
>>>>> hepler, 0 means VRAM helper, and the default (-1) means auto selection
>>>>> according to drm_arch_can_wc_memory().
>>>> Sorry won't happen. There's one memory manager and that's it.
>>>>
>>>> The question is why there is a difference between the two. Because
>>>> conceptually, it's both software rendering that copies the final image
>>>> into video ram. Why is that much faster with VRAM helpers?
>>> Correct me if I'm wrong.
>>>
>>> SHMEM helper means "copy damage data to a fixed VRAM buffer", VRAM
>>> helper means "double buffers and swapping the two". So if WC is not
>>> supported, SHMEM helper is slower from visible effect.
>> First of all, which component is slow? The kernel console, the desktop,
>> something else?
> "Slow" here means the desktop ui is not smooth, not kernel console,
> and not data copy rate.

For a simple test you can set

   mode_config.prefer_shadow = false

(It's somewhere in your patch). This will disable Xorg's shadow buffer 
and make it operate directly on I/O memory. This should be much slower then.


>
>> On your question. This is all software rendering. In the case of
>> GEM-SHMEM, we mmap shmem pages to user-space compositors and let them
>> draw the UI. That should be fast because these SHMEM pages should be
>> mapped with full caching. The WC caching is the exception here. This
>> could be the problem. Maybe these pages are uncached for some reason.
>> But so far, we've not touched VRAM at all. After rendering to the
>> provided pages, the compositor instructs the DRM driver to flush the
>> changes to VRAM. That involves a vmap of the I/O range and a
>> memcpy_toio(). Without WC caching, this will be slow. It is optimized by
>> using damage information; only the updated part of the screen will be
>> copied.
>>
>> With GEM-VRAM, the kernel mmap's the VRAM's I/O range to the compositor.
>> The compositor renders into a malloc'ed memory buffer and then copies
>> the result over to the mmap'ed range fom the driver. (And essentially
>> into the VRAM). If your platform does not have WC caching, this would be
>> uncached and fairly slow.  The compositor then instructs the driver to
>> swap buffers, which is always fast because we've already done he copying
>> in user space.
>>
>> Now the question is why the GEM-SHMEM code is slower than the GEM-VRAM
>> path. In principle, they both do the same work.
> Yes, they do the same work, so the data copy rate may be the same. But
> GEM-SHMEM is an in-place update while GEM-VRAM is an off-screen
> update, so the desktop effect is different.

Oh, so you see tearing.

Years ago, we had a bug report about ast's lack of performance on x86. 
Back then, we had a VRAM-based memory manager. It turned out that ast 
was misconfigured to use uncached framebuffer access, just like on your 
system. See [1][2]. Hence, returning to this memory manager would just 
paper over the fact that framebuffer access is too slow. And it would 
bring disadvantages to other users.

Ast hardware provides a vretrace interrupt AFAIK. Getting this to work 
would allow for the copying to take place during the display's vblank 
interval. This might be a solution that benefits everyone.

Best regards
Thomas

[1] https://bugzilla.opensuse.org/show_bug.cgi?id=1112963
[2] 
https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5478ad10e7850ce3d8b7056db05ddfa3c9ddad9a

>
> Huacai
>
>> Best regard
>> Thomas
>>
>>>
>>> Huacai
>>>
>>>> Best regards
>>>> Thomas
>>>>
>>>>> Signed-off-by: Huacai Chen <chenhuacai at loongson.cn>
>>>>> ---
>>>>>     drivers/gpu/drm/ast/Kconfig    |   3 +
>>>>>     drivers/gpu/drm/ast/ast_drv.c  |  31 ++++++++--
>>>>>     drivers/gpu/drm/ast/ast_drv.h  |   6 +-
>>>>>     drivers/gpu/drm/ast/ast_mm.c   |  11 +++-
>>>>>     drivers/gpu/drm/ast/ast_mode.c | 105 +++++++++++++++++++++++++--------
>>>>>     5 files changed, 124 insertions(+), 32 deletions(-)
>>>>>
>>>>> diff --git a/drivers/gpu/drm/ast/Kconfig b/drivers/gpu/drm/ast/Kconfig
>>>>> index da0663542e8a..ed07ef70072f 100644
>>>>> --- a/drivers/gpu/drm/ast/Kconfig
>>>>> +++ b/drivers/gpu/drm/ast/Kconfig
>>>>> @@ -5,6 +5,9 @@ config DRM_AST
>>>>>         select DRM_CLIENT_SELECTION
>>>>>         select DRM_GEM_SHMEM_HELPER
>>>>>         select DRM_KMS_HELPER
>>>>> +     select DRM_TTM
>>>>> +     select DRM_TTM_HELPER
>>>>> +     select DRM_VRAM_HELPER
>>>>>         select I2C
>>>>>         select I2C_ALGOBIT
>>>>>         help
>>>>> diff --git a/drivers/gpu/drm/ast/ast_drv.c b/drivers/gpu/drm/ast/ast_drv.c
>>>>> index ff3bcdd1cff2..a0c693844f1e 100644
>>>>> --- a/drivers/gpu/drm/ast/ast_drv.c
>>>>> +++ b/drivers/gpu/drm/ast/ast_drv.c
>>>>> @@ -33,9 +33,12 @@
>>>>>
>>>>>     #include <drm/clients/drm_client_setup.h>
>>>>>     #include <drm/drm_atomic_helper.h>
>>>>> +#include <drm/drm_cache.h>
>>>>>     #include <drm/drm_drv.h>
>>>>>     #include <drm/drm_fbdev_shmem.h>
>>>>> +#include <drm/drm_fbdev_ttm.h>
>>>>>     #include <drm/drm_gem_shmem_helper.h>
>>>>> +#include <drm/drm_gem_vram_helper.h>
>>>>>     #include <drm/drm_module.h>
>>>>>     #include <drm/drm_probe_helper.h>
>>>>>
>>>>> @@ -46,13 +49,18 @@ static int ast_modeset = -1;
>>>>>     MODULE_PARM_DESC(modeset, "Disable/Enable modesetting");
>>>>>     module_param_named(modeset, ast_modeset, int, 0400);
>>>>>
>>>>> +int ast_shmem = -1;
>>>>> +
>>>>> +MODULE_PARM_DESC(shmem, "1 = SHMEM helper, 0 = VRAM helper, -1 = Auto");
>>>>> +module_param_named(shmem, ast_shmem, int, 0400);
>>>>> +
>>>>>     /*
>>>>>      * DRM driver
>>>>>      */
>>>>>
>>>>>     DEFINE_DRM_GEM_FOPS(ast_fops);
>>>>>
>>>>> -static const struct drm_driver ast_driver = {
>>>>> +static struct drm_driver ast_driver = {
>>>>>         .driver_features = DRIVER_ATOMIC |
>>>>>                            DRIVER_GEM |
>>>>>                            DRIVER_MODESET,
>>>>> @@ -63,9 +71,6 @@ static const struct drm_driver ast_driver = {
>>>>>         .major = DRIVER_MAJOR,
>>>>>         .minor = DRIVER_MINOR,
>>>>>         .patchlevel = DRIVER_PATCHLEVEL,
>>>>> -
>>>>> -     DRM_GEM_SHMEM_DRIVER_OPS,
>>>>> -     DRM_FBDEV_SHMEM_DRIVER_OPS,
>>>>>     };
>>>>>
>>>>>     /*
>>>>> @@ -280,6 +285,24 @@ static int ast_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>>>>>         struct drm_device *drm;
>>>>>         bool need_post = false;
>>>>>
>>>>> +     if (ast_shmem == -1)
>>>>> +             ast_shmem = drm_arch_can_wc_memory() ? 1 : 0;
>>>>> +
>>>>> +     if (ast_shmem) {
>>>>> +             ast_driver.dumb_create = drm_gem_shmem_dumb_create;
>>>>> +             ast_driver.gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table;
>>>>> +#ifdef CONFIG_DRM_FBDEV_EMULATION
>>>>> +             ast_driver.fbdev_probe = drm_fbdev_shmem_driver_fbdev_probe;
>>>>> +#endif
>>>>> +     } else {
>>>>> +             ast_driver.dumb_create = drm_gem_vram_driver_dumb_create;
>>>>> +             ast_driver.dumb_map_offset = drm_gem_ttm_dumb_map_offset;
>>>>> +             ast_driver.debugfs_init = drm_vram_mm_debugfs_init;
>>>>> +#ifdef CONFIG_DRM_FBDEV_EMULATION
>>>>> +             ast_driver.fbdev_probe = drm_fbdev_ttm_driver_fbdev_probe;
>>>>> +#endif
>>>>> +     }
>>>>> +
>>>>>         ret = aperture_remove_conflicting_pci_devices(pdev, ast_driver.name);
>>>>>         if (ret)
>>>>>                 return ret;
>>>>> diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
>>>>> index 6b4305ac07d4..3fcf6717ad8a 100644
>>>>> --- a/drivers/gpu/drm/ast/ast_drv.h
>>>>> +++ b/drivers/gpu/drm/ast/ast_drv.h
>>>>> @@ -29,6 +29,7 @@
>>>>>     #define __AST_DRV_H__
>>>>>
>>>>>     #include <linux/io.h>
>>>>> +#include <linux/iosys-map.h>
>>>>>     #include <linux/types.h>
>>>>>
>>>>>     #include <drm/drm_connector.h>
>>>>> @@ -53,6 +54,8 @@
>>>>>
>>>>>     #define __AST_CHIP(__gen, __index)  ((__gen) << 16 | (__index))
>>>>>
>>>>> +extern int ast_shmem;
>>>>> +
>>>>>     enum ast_chip {
>>>>>         /* 1st gen */
>>>>>         AST1000 = __AST_CHIP(1, 0), // unused
>>>>> @@ -130,7 +133,8 @@ enum ast_config_mode {
>>>>>     struct ast_plane {
>>>>>         struct drm_plane base;
>>>>>
>>>>> -     void __iomem *vaddr;
>>>>> +     struct drm_gem_vram_object *gbo;
>>>>> +     struct iosys_map map;
>>>>>         u64 offset;
>>>>>         unsigned long size;
>>>>>     };
>>>>> diff --git a/drivers/gpu/drm/ast/ast_mm.c b/drivers/gpu/drm/ast/ast_mm.c
>>>>> index 6dfe6d9777d4..588326b7d53e 100644
>>>>> --- a/drivers/gpu/drm/ast/ast_mm.c
>>>>> +++ b/drivers/gpu/drm/ast/ast_mm.c
>>>>> @@ -28,6 +28,7 @@
>>>>>
>>>>>     #include <linux/pci.h>
>>>>>
>>>>> +#include <drm/drm_gem_vram_helper.h>
>>>>>     #include <drm/drm_managed.h>
>>>>>     #include <drm/drm_print.h>
>>>>>
>>>>> @@ -87,9 +88,13 @@ int ast_mm_init(struct ast_device *ast)
>>>>>
>>>>>         vram_size = ast_get_vram_size(ast);
>>>>>
>>>>> -     ast->vram = devm_ioremap_wc(dev->dev, base, vram_size);
>>>>> -     if (!ast->vram)
>>>>> -             return -ENOMEM;
>>>>> +     if (!ast_shmem)
>>>>> +             drmm_vram_helper_init(dev, base, vram_size);
>>>>> +     else {
>>>>> +             ast->vram = devm_ioremap_wc(dev->dev, base, vram_size);
>>>>> +             if (!ast->vram)
>>>>> +                     return -ENOMEM;
>>>>> +     }
>>>>>
>>>>>         ast->vram_base = base;
>>>>>         ast->vram_size = vram_size;
>>>>> diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
>>>>> index 9d5321c81e68..0744d1ac5dfb 100644
>>>>> --- a/drivers/gpu/drm/ast/ast_mode.c
>>>>> +++ b/drivers/gpu/drm/ast/ast_mode.c
>>>>> @@ -41,6 +41,7 @@
>>>>>     #include <drm/drm_gem_atomic_helper.h>
>>>>>     #include <drm/drm_gem_framebuffer_helper.h>
>>>>>     #include <drm/drm_gem_shmem_helper.h>
>>>>> +#include <drm/drm_gem_vram_helper.h>
>>>>>     #include <drm/drm_managed.h>
>>>>>     #include <drm/drm_panic.h>
>>>>>     #include <drm/drm_probe_helper.h>
>>>>> @@ -566,8 +567,7 @@ static void ast_wait_for_vretrace(struct ast_device *ast)
>>>>>      */
>>>>>
>>>>>     static int ast_plane_init(struct drm_device *dev, struct ast_plane *ast_plane,
>>>>> -                       void __iomem *vaddr, u64 offset, unsigned long size,
>>>>> -                       uint32_t possible_crtcs,
>>>>> +                       u64 offset, unsigned long size, uint32_t possible_crtcs,
>>>>>                           const struct drm_plane_funcs *funcs,
>>>>>                           const uint32_t *formats, unsigned int format_count,
>>>>>                           const uint64_t *format_modifiers,
>>>>> @@ -575,7 +575,6 @@ static int ast_plane_init(struct drm_device *dev, struct ast_plane *ast_plane,
>>>>>     {
>>>>>         struct drm_plane *plane = &ast_plane->base;
>>>>>
>>>>> -     ast_plane->vaddr = vaddr;
>>>>>         ast_plane->offset = offset;
>>>>>         ast_plane->size = size;
>>>>>
>>>>> @@ -630,7 +629,7 @@ static void ast_handle_damage(struct ast_plane *ast_plane, struct iosys_map *src
>>>>>                               struct drm_framebuffer *fb,
>>>>>                               const struct drm_rect *clip)
>>>>>     {
>>>>> -     struct iosys_map dst = IOSYS_MAP_INIT_VADDR_IOMEM(ast_plane->vaddr);
>>>>> +     struct iosys_map dst = ast_plane->map;
>>>>>
>>>>>         iosys_map_incr(&dst, drm_fb_clip_offset(fb->pitches[0], fb->format, clip));
>>>>>         drm_fb_memcpy(&dst, fb->pitches, src, fb, clip);
>>>>> @@ -650,6 +649,7 @@ static void ast_primary_plane_helper_atomic_update(struct drm_plane *plane,
>>>>>         struct drm_crtc *crtc = plane_state->crtc;
>>>>>         struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
>>>>>         struct drm_rect damage;
>>>>> +     struct drm_gem_vram_object *gbo;
>>>>>         struct drm_atomic_helper_damage_iter iter;
>>>>>
>>>>>         if (!old_fb || (fb->format != old_fb->format) || crtc_state->mode_changed) {
>>>>> @@ -660,9 +660,15 @@ static void ast_primary_plane_helper_atomic_update(struct drm_plane *plane,
>>>>>                 ast_set_vbios_color_reg(ast, fb->format, vbios_mode_info);
>>>>>         }
>>>>>
>>>>> -     drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);
>>>>> -     drm_atomic_for_each_plane_damage(&iter, &damage) {
>>>>> -             ast_handle_damage(ast_plane, shadow_plane_state->data, fb, &damage);
>>>>> +     if (!ast_shmem) {
>>>>> +             gbo = drm_gem_vram_of_gem(fb->obj[0]);
>>>>> +             ast_plane->offset = drm_gem_vram_offset(gbo);
>>>>> +             ast_set_start_address_crt1(ast, (u32)ast_plane->offset);
>>>>> +     } else {
>>>>> +             drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);
>>>>> +             drm_atomic_for_each_plane_damage(&iter, &damage) {
>>>>> +                     ast_handle_damage(ast_plane, shadow_plane_state->data, fb, &damage);
>>>>> +             }
>>>>>         }
>>>>>
>>>>>         /*
>>>>> @@ -704,19 +710,18 @@ static int ast_primary_plane_helper_get_scanout_buffer(struct drm_plane *plane,
>>>>>     {
>>>>>         struct ast_plane *ast_plane = to_ast_plane(plane);
>>>>>
>>>>> -     if (plane->state && plane->state->fb && ast_plane->vaddr) {
>>>>> +     if (plane->state && plane->state->fb && ast_plane->map.vaddr_iomem) {
>>>>>                 sb->format = plane->state->fb->format;
>>>>>                 sb->width = plane->state->fb->width;
>>>>>                 sb->height = plane->state->fb->height;
>>>>>                 sb->pitch[0] = plane->state->fb->pitches[0];
>>>>> -             iosys_map_set_vaddr_iomem(&sb->map[0], ast_plane->vaddr);
>>>>> +             iosys_map_set_vaddr_iomem(&sb->map[0], ast_plane->map.vaddr_iomem);
>>>>>                 return 0;
>>>>>         }
>>>>>         return -ENODEV;
>>>>>     }
>>>>>
>>>>> -static const struct drm_plane_helper_funcs ast_primary_plane_helper_funcs = {
>>>>> -     DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,
>>>>> +static struct drm_plane_helper_funcs ast_primary_plane_helper_funcs = {
>>>>>         .atomic_check = ast_primary_plane_helper_atomic_check,
>>>>>         .atomic_update = ast_primary_plane_helper_atomic_update,
>>>>>         .atomic_enable = ast_primary_plane_helper_atomic_enable,
>>>>> @@ -724,11 +729,10 @@ static const struct drm_plane_helper_funcs ast_primary_plane_helper_funcs = {
>>>>>         .get_scanout_buffer = ast_primary_plane_helper_get_scanout_buffer,
>>>>>     };
>>>>>
>>>>> -static const struct drm_plane_funcs ast_primary_plane_funcs = {
>>>>> +static struct drm_plane_funcs ast_primary_plane_funcs = {
>>>>>         .update_plane = drm_atomic_helper_update_plane,
>>>>>         .disable_plane = drm_atomic_helper_disable_plane,
>>>>>         .destroy = drm_plane_cleanup,
>>>>> -     DRM_GEM_SHADOW_PLANE_FUNCS,
>>>>>     };
>>>>>
>>>>>     static int ast_primary_plane_init(struct ast_device *ast)
>>>>> @@ -737,12 +741,28 @@ static int ast_primary_plane_init(struct ast_device *ast)
>>>>>         struct ast_plane *ast_primary_plane = &ast->primary_plane;
>>>>>         struct drm_plane *primary_plane = &ast_primary_plane->base;
>>>>>         void __iomem *vaddr = ast->vram;
>>>>> -     u64 offset = 0; /* with shmem, the primary plane is always at offset 0 */
>>>>> +     u64 offset = 0; /* the primary plane is initially at offset 0 */
>>>>>         unsigned long cursor_size = roundup(AST_HWC_SIZE + AST_HWC_SIGNATURE_SIZE, PAGE_SIZE);
>>>>>         unsigned long size = ast->vram_fb_available - cursor_size;
>>>>>         int ret;
>>>>>
>>>>> -     ret = ast_plane_init(dev, ast_primary_plane, vaddr, offset, size,
>>>>> +     if (ast_shmem) {
>>>>> +             ast_primary_plane_funcs.reset = drm_gem_reset_shadow_plane;
>>>>> +             ast_primary_plane_funcs.atomic_duplicate_state = drm_gem_duplicate_shadow_plane_state;
>>>>> +             ast_primary_plane_funcs.atomic_destroy_state = drm_gem_destroy_shadow_plane_state;
>>>>> +             ast_primary_plane_helper_funcs.begin_fb_access = drm_gem_begin_shadow_fb_access;
>>>>> +             ast_primary_plane_helper_funcs.end_fb_access = drm_gem_end_shadow_fb_access;
>>>>> +     } else {
>>>>> +             ast_primary_plane_funcs.reset = drm_atomic_helper_plane_reset;
>>>>> +             ast_primary_plane_funcs.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state;
>>>>> +             ast_primary_plane_funcs.atomic_destroy_state = drm_atomic_helper_plane_destroy_state;
>>>>> +             ast_primary_plane_helper_funcs.prepare_fb = drm_gem_vram_plane_helper_prepare_fb;
>>>>> +             ast_primary_plane_helper_funcs.cleanup_fb = drm_gem_vram_plane_helper_cleanup_fb;
>>>>> +     }
>>>>> +
>>>>> +     iosys_map_set_vaddr_iomem(&ast_primary_plane->map, vaddr);
>>>>> +
>>>>> +     ret = ast_plane_init(dev, ast_primary_plane, offset, size,
>>>>>                              0x01, &ast_primary_plane_funcs,
>>>>>                              ast_primary_plane_formats, ARRAY_SIZE(ast_primary_plane_formats),
>>>>>                              NULL, DRM_PLANE_TYPE_PRIMARY);
>>>>> @@ -902,10 +922,11 @@ static void ast_cursor_plane_helper_atomic_update(struct drm_plane *plane,
>>>>>         struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane);
>>>>>         struct ast_device *ast = to_ast_device(plane->dev);
>>>>>         struct iosys_map src_map = shadow_plane_state->data[0];
>>>>> +     struct iosys_map dst_map = ast_plane->map;
>>>>>         struct drm_rect damage;
>>>>>         const u8 *src = src_map.vaddr; /* TODO: Use mapping abstraction properly */
>>>>>         u64 dst_off = ast_plane->offset;
>>>>> -     u8 __iomem *dst = ast_plane->vaddr; /* TODO: Use mapping abstraction properly */
>>>>> +     u8 __iomem *dst = dst_map.vaddr_iomem; /* TODO: Use mapping abstraction properly */
>>>>>         u8 __iomem *sig = dst + AST_HWC_SIZE; /* TODO: Use mapping abstraction properly */
>>>>>         unsigned int offset_x, offset_y;
>>>>>         u16 x, y;
>>>>> @@ -967,10 +988,22 @@ static const struct drm_plane_helper_funcs ast_cursor_plane_helper_funcs = {
>>>>>         .atomic_disable = ast_cursor_plane_helper_atomic_disable,
>>>>>     };
>>>>>
>>>>> -static const struct drm_plane_funcs ast_cursor_plane_funcs = {
>>>>> +static void ast_cursor_plane_destroy(struct drm_plane *plane)
>>>>> +{
>>>>> +     struct ast_plane *ast_plane = to_ast_plane(plane);
>>>>> +     struct drm_gem_vram_object *gbo = ast_plane->gbo;
>>>>> +     struct iosys_map map = ast_plane->map;
>>>>> +
>>>>> +     drm_gem_vram_vunmap(gbo, &map);
>>>>> +     drm_gem_vram_unpin(gbo);
>>>>> +     drm_gem_vram_put(gbo);
>>>>> +
>>>>> +     drm_plane_cleanup(plane);
>>>>> +}
>>>>> +
>>>>> +static struct drm_plane_funcs ast_cursor_plane_funcs = {
>>>>>         .update_plane = drm_atomic_helper_update_plane,
>>>>>         .disable_plane = drm_atomic_helper_disable_plane,
>>>>> -     .destroy = drm_plane_cleanup,
>>>>>         DRM_GEM_SHADOW_PLANE_FUNCS,
>>>>>     };
>>>>>
>>>>> @@ -979,6 +1012,8 @@ static int ast_cursor_plane_init(struct ast_device *ast)
>>>>>         struct drm_device *dev = &ast->base;
>>>>>         struct ast_plane *ast_cursor_plane = &ast->cursor_plane;
>>>>>         struct drm_plane *cursor_plane = &ast_cursor_plane->base;
>>>>> +     struct drm_gem_vram_object *gbo;
>>>>> +     struct iosys_map map;
>>>>>         size_t size;
>>>>>         void __iomem *vaddr;
>>>>>         u64 offset;
>>>>> @@ -994,10 +1029,25 @@ static int ast_cursor_plane_init(struct ast_device *ast)
>>>>>         if (ast->vram_fb_available < size)
>>>>>                 return -ENOMEM;
>>>>>
>>>>> -     vaddr = ast->vram + ast->vram_fb_available - size;
>>>>> -     offset = ast->vram_fb_available - size;
>>>>> +     if (ast_shmem) {
>>>>> +             vaddr = ast->vram + ast->vram_fb_available - size;
>>>>> +             offset = ast->vram_fb_available - size;
>>>>> +             iosys_map_set_vaddr_iomem(&ast_cursor_plane->map, vaddr);
>>>>> +             ast_cursor_plane_funcs.destroy = drm_plane_cleanup;
>>>>> +     } else {
>>>>> +             gbo = drm_gem_vram_create(dev, size, 0);
>>>>> +             if (IS_ERR(gbo))
>>>>> +                     return PTR_ERR(gbo);
>>>>> +
>>>>> +             drm_gem_vram_pin(gbo, DRM_GEM_VRAM_PL_FLAG_VRAM | DRM_GEM_VRAM_PL_FLAG_TOPDOWN);
>>>>> +             drm_gem_vram_vmap(gbo, &map);
>>>>> +             offset = drm_gem_vram_offset(gbo);
>>>>> +             ast_cursor_plane->gbo = gbo;
>>>>> +             ast_cursor_plane->map = map;
>>>>> +             ast_cursor_plane_funcs.destroy = ast_cursor_plane_destroy;
>>>>> +     }
>>>>>
>>>>> -     ret = ast_plane_init(dev, ast_cursor_plane, vaddr, offset, size,
>>>>> +     ret = ast_plane_init(dev, ast_cursor_plane, offset, size,
>>>>>                              0x01, &ast_cursor_plane_funcs,
>>>>>                              ast_cursor_plane_formats, ARRAY_SIZE(ast_cursor_plane_formats),
>>>>>                              NULL, DRM_PLANE_TYPE_CURSOR);
>>>>> @@ -1348,9 +1398,7 @@ static enum drm_mode_status ast_mode_config_mode_valid(struct drm_device *dev,
>>>>>         return MODE_OK;
>>>>>     }
>>>>>
>>>>> -static const struct drm_mode_config_funcs ast_mode_config_funcs = {
>>>>> -     .fb_create = drm_gem_fb_create_with_dirty,
>>>>> -     .mode_valid = ast_mode_config_mode_valid,
>>>>> +static struct drm_mode_config_funcs ast_mode_config_funcs = {
>>>>>         .atomic_check = drm_atomic_helper_check,
>>>>>         .atomic_commit = drm_atomic_helper_commit,
>>>>>     };
>>>>> @@ -1372,6 +1420,15 @@ int ast_mode_config_init(struct ast_device *ast)
>>>>>         dev->mode_config.min_width = 0;
>>>>>         dev->mode_config.min_height = 0;
>>>>>         dev->mode_config.preferred_depth = 24;
>>>>> +     dev->mode_config.prefer_shadow = !ast_shmem;
>>>>> +
>>>>> +     if (!ast_shmem) {
>>>>> +             ast_mode_config_funcs.fb_create = drm_gem_fb_create;
>>>>> +             ast_mode_config_funcs.mode_valid = drm_vram_helper_mode_valid;
>>>>> +     } else {
>>>>> +             ast_mode_config_funcs.fb_create = drm_gem_fb_create_with_dirty;
>>>>> +             ast_mode_config_funcs.mode_valid = ast_mode_config_mode_valid;
>>>>> +     }
>>>>>
>>>>>         if (ast->chip == AST2100 || // GEN2, but not AST1100 (?)
>>>>>             ast->chip == AST2200 || // GEN3, but not AST2150 (?)
>>>> --
>>>> --
>>>> Thomas Zimmermann
>>>> Graphics Driver Developer
>>>> SUSE Software Solutions Germany GmbH
>>>> Frankenstrasse 146, 90461 Nuernberg, Germany
>>>> GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
>>>> HRB 36809 (AG Nuernberg)
>>>>
>> --
>> --
>> Thomas Zimmermann
>> Graphics Driver Developer
>> SUSE Software Solutions Germany GmbH
>> Frankenstrasse 146, 90461 Nuernberg, Germany
>> GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
>> HRB 36809 (AG Nuernberg)
>>

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)



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