Hi Thomas.
>
> #include "hibmc_drm_drv.h"
> @@ -100,28 +102,41 @@ static int hibmc_plane_atomic_check(struct drm_plane
> *plane,
> static void hibmc_plane_atomic_update(struct drm_plane *plane,
> struct drm_atomic_commit *state)
> {
> + struct hibmc_drm_private *priv = to_hibmc_drm_private(plane->dev);
> struct drm_plane_state *new_state =
> drm_atomic_get_new_plane_state(state, plane);
> + struct drm_shadow_plane_state *shadow_plane_state =
> to_drm_shadow_plane_state(new_state);
> struct drm_framebuffer *fb = new_state->fb;
> + struct drm_plane_state *old_state =
> drm_atomic_get_old_plane_state(state, plane);
> + u32 gpu_addr = 0;
> u32 reg;
> - s64 gpu_addr = 0;
> u32 line_l;
> - struct hibmc_drm_private *priv = to_hibmc_drm_private(plane->dev);
> - struct drm_gem_vram_object *gbo;
>
> - if (!new_state->fb)
> + if (!fb)
> return;
>
> - gbo = drm_gem_vram_of_gem(new_state->fb->obj[0]);
> + if (drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE) == 0) {
> + struct drm_rect damage;
> + struct drm_atomic_helper_damage_iter iter;
> +
> + drm_atomic_helper_damage_iter_init(&iter, old_state, new_state);
> + drm_atomic_for_each_plane_damage(&iter, &damage) {
> + struct iosys_map dst[DRM_FORMAT_MAX_PLANES] = {
> + IOSYS_MAP_INIT_VADDR_IOMEM(priv->vram +
> gpu_addr),
> + };
>
> - gpu_addr = drm_gem_vram_offset(gbo);
> - if (WARN_ON_ONCE(gpu_addr < 0))
> - return; /* Bug: we didn't pin the BO to VRAM in prepare_fb. */
> + iosys_map_incr(&dst[0],
> + drm_fb_clip_offset(fb->pitches[0],
> fb->format, &damage));
> + drm_fb_memcpy(dst, fb->pitches,
> shadow_plane_state->data, fb, &damage);
> + }
> +
> + drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
> + }
This implementation uses shadow planes for damage rect updates. If the entire
plane is updated frequently, could this
lead to a performance drop or frame drops?
Originally, the window system(X11/Wayland) drew directly to the hardware
framebuffer, but now there is an extra copy in
`atomic_update`.
>
> writel(gpu_addr, priv->mmio + HIBMC_CRT_FB_ADDRESS);
>
> reg = drm_format_info_min_pitch(fb->format, 0, fb->width);
>
> - line_l = new_state->fb->pitches[0];
> + line_l = fb->pitches[0];
> writel(HIBMC_FIELD(HIBMC_CRT_FB_WIDTH_WIDTH, reg) |
> HIBMC_FIELD(HIBMC_CRT_FB_WIDTH_OFFS, line_l),
> priv->mmio + HIBMC_CRT_FB_WIDTH);
> @@ -149,13 +164,11 @@ static const struct drm_plane_funcs hibmc_plane_funcs =
> {
> .update_plane = drm_atomic_helper_update_plane,
> .disable_plane = drm_atomic_helper_disable_plane,
> .destroy = drm_plane_cleanup,
> - .reset = drm_atomic_helper_plane_reset,
> - .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
> - .atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
> + DRM_GEM_SHADOW_PLANE_FUNCS,
> };
>
> static const struct drm_plane_helper_funcs hibmc_plane_helper_funcs = {
> - DRM_GEM_VRAM_PLANE_HELPER_FUNCS,
> + DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,
> .atomic_check = hibmc_plane_atomic_check,
> .atomic_update = hibmc_plane_atomic_update,
> };
> @@ -515,6 +528,7 @@ int hibmc_de_init(struct hibmc_drm_private *priv)
> }
>
> drm_plane_helper_add(plane, &hibmc_plane_helper_funcs);
> + drm_plane_enable_fb_damage_clips(plane);
>
> ret = drm_crtc_init_with_planes(dev, crtc, plane,
> NULL, &hibmc_crtc_funcs, NULL);
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> index 99b36de1fe13..19d3193e2f76 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> @@ -18,9 +18,10 @@
> #include <drm/clients/drm_client_setup.h>
> #include <drm/drm_atomic_helper.h>
> #include <drm/drm_drv.h>
> -#include <drm/drm_fbdev_ttm.h>
> +#include <drm/drm_dumb_buffers.h>
> +#include <drm/drm_fbdev_shmem.h>
> #include <drm/drm_gem_framebuffer_helper.h>
> -#include <drm/drm_gem_vram_helper.h>
> +#include <drm/drm_gem_shmem_helper.h>
> #include <drm/drm_managed.h>
> #include <drm/drm_module.h>
> #include <drm/drm_vblank.h>
> @@ -71,7 +72,13 @@ static irqreturn_t hibmc_dp_interrupt(int irq, void *arg)
> static int hibmc_dumb_create(struct drm_file *file, struct drm_device *dev,
> struct drm_mode_create_dumb *args)
> {
> - return drm_gem_vram_fill_create_dumb(file, dev, 0, 128, args);
> + int ret;
> +
> + ret = drm_mode_size_dumb(dev, args, SZ_128, 0);
> + if (ret)
> + return ret;
> +
> + return drm_gem_shmem_create_with_handle(file, dev, args->size,
> &args->handle);
> }
>
> static const struct drm_driver hibmc_driver = {
> @@ -81,10 +88,9 @@ static const struct drm_driver hibmc_driver = {
> .desc = "hibmc drm driver",
> .major = 1,
> .minor = 0,
> - .debugfs_init = drm_vram_mm_debugfs_init,
> - .dumb_create = hibmc_dumb_create,
> - .dumb_map_offset = drm_gem_ttm_dumb_map_offset,
> - DRM_FBDEV_TTM_DRIVER_OPS,
> + .gem_prime_import = drm_gem_shmem_prime_import_no_map,
> + .dumb_create = hibmc_dumb_create,
> + DRM_FBDEV_SHMEM_DRIVER_OPS,
> };
>
> static int __maybe_unused hibmc_pm_suspend(struct device *dev)
> @@ -106,11 +112,32 @@ static const struct dev_pm_ops hibmc_pm_ops = {
> hibmc_pm_resume)
> };
>
> +static enum drm_mode_status hibmc_mode_config_mode_valid(struct drm_device
> *dev,
> + const struct
> drm_display_mode *mode)
> +{
> + const struct drm_format_info *info =
> + drm_get_format_info(dev, DRM_FORMAT_XRGB8888,
> DRM_FORMAT_MOD_LINEAR);
> + struct hibmc_drm_private *priv = to_hibmc_drm_private(dev);
> + unsigned long max_fb_size = priv->vram_size;
> + u64 pitch;
> +
> + if (drm_WARN_ON_ONCE(dev, !info))
> + return MODE_ERROR; /* driver bug */
> +
> + pitch = drm_format_info_min_pitch(info, 0, mode->hdisplay);
> + if (!pitch)
> + return MODE_BAD_WIDTH;
> + else if (pitch > max_fb_size / mode->vdisplay)
> + return MODE_MEM;
> +
I reviewed the AST and Cirrus implementations, and they include checks for the
maximum size supported by the hardware.
The hardware FB width register has only 14 bits, and the
HIBMC_CRT_FB_WIDTH_WIDTH_MASK macro defines the maximum size as
0x3FFF. Would adding the following check make the code more rigorous?
Also, the pitch requires 128-byte alignment. Should we add a check here, or
does the buffer created by
`hibmc_dumb_create` already ensure that the FB start address is aligned to 128
bytes via `SZ_128`? I’m not entirely sure
about this.
Of course, the original code used `drm_vram_helper_mode_valid` without strictly
checking these hardware limitations.
Thank you for your modification.
Thanks,
Yongbang.
> + return MODE_OK;
> +}
> +
> static const struct drm_mode_config_funcs hibmc_mode_funcs = {
> - .mode_valid = drm_vram_helper_mode_valid,
> + .mode_valid = hibmc_mode_config_mode_valid,
> .atomic_check = drm_atomic_helper_check,
> .atomic_commit = drm_atomic_helper_commit,
> - .fb_create = drm_gem_fb_create,
> + .fb_create = drm_gem_fb_create_with_dirty,
> };
>
> static int hibmc_kms_init(struct hibmc_drm_private *priv)
> @@ -130,7 +157,6 @@ static int hibmc_kms_init(struct hibmc_drm_private *priv)
> dev->mode_config.max_height = 1200;
>
> dev->mode_config.preferred_depth = 24;
> - dev->mode_config.prefer_shadow = 1;
>
> dev->mode_config.funcs = (void *)&hibmc_mode_funcs;
>
> @@ -335,18 +361,22 @@ static int hibmc_load(struct drm_device *dev)
> {
> struct pci_dev *pdev = to_pci_dev(dev->dev);
> struct hibmc_drm_private *priv = to_hibmc_drm_private(dev);
> + resource_size_t vram_base, vram_size;
> int ret;
>
> ret = hibmc_hw_init(priv);
> if (ret)
> return ret;
>
> - ret = drmm_vram_helper_init(dev, pci_resource_start(pdev, 0),
> - pci_resource_len(pdev, 0));
> - if (ret) {
> - drm_err(dev, "Error initializing VRAM MM; %d\n", ret);
> - return ret;
> - }
> + vram_base = pci_resource_start(pdev, 0);
> + vram_size = pci_resource_len(pdev, 0);
> +
> + priv->vram = devm_ioremap_wc(dev->dev, vram_base, vram_size);
> + if (!priv->vram)
> + return -ENOMEM;
> +
> + priv->vram_base = vram_base;
> + priv->vram_size = vram_size;
>
> ret = hibmc_kms_init(priv);
> if (ret)
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
> b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
> index cd3a3fca1fe6..dce8572bf63e 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
> +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
> @@ -38,6 +38,11 @@ struct hibmc_drm_private {
> /* hw */
> void __iomem *mmio;
>
> + /* vram */
> + void __iomem *vram;
> + resource_size_t vram_base;
> + resource_size_t vram_size;
> +
> /* drm */
> struct drm_device dev;
> struct drm_plane primary_plane;
> diff --git a/include/drm/drm_gem_shmem_helper.h
> b/include/drm/drm_gem_shmem_helper.h
> index 5ccdae21b94a..86b967174b60 100644
> --- a/include/drm/drm_gem_shmem_helper.h
> +++ b/include/drm/drm_gem_shmem_helper.h
> @@ -141,6 +141,10 @@ struct sg_table *drm_gem_shmem_get_pages_sgt(struct
> drm_gem_shmem_object *shmem)
> void drm_gem_shmem_print_info(const struct drm_gem_shmem_object *shmem,
> struct drm_printer *p, unsigned int indent);
>
> +int drm_gem_shmem_create_with_handle(struct drm_file *file_priv,
> + struct drm_device *dev, size_t size,
> + uint32_t *handle);
> +
> extern const struct vm_operations_struct drm_gem_shmem_vm_ops;
>
> /*
