[PATCHv3/RFC 1/4] drm/arm: Factor out generic afbc helpers
Daniel Vetter
daniel at ffwll.ch
Mon Nov 25 08:55:06 UTC 2019
On Thu, Nov 21, 2019 at 06:22:44PM +0100, Andrzej Pietrasiewicz wrote:
> These are useful for other users of afbc, e.g. rockchip.
>
> Signed-off-by: Andrzej Pietrasiewicz <andrzej.p at collabora.com>
> ---
> drivers/gpu/drm/Makefile | 2 +-
> drivers/gpu/drm/drm_afbc.c | 84 +++++++++++++++++++++++++++++++
> drivers/gpu/drm/drm_fourcc.c | 11 +++-
> drivers/gpu/drm/drm_framebuffer.c | 71 +++++++++++++++++++++++++-
> include/drm/drm_afbc.h | 35 +++++++++++++
> 5 files changed, 199 insertions(+), 4 deletions(-)
> create mode 100644 drivers/gpu/drm/drm_afbc.c
> create mode 100644 include/drm/drm_afbc.h
>
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index d9bcc9f2a0a4..3a58f30b83a6 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -44,7 +44,7 @@ drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_dsc.o drm_probe_helper
> drm_simple_kms_helper.o drm_modeset_helper.o \
> drm_scdc_helper.o drm_gem_framebuffer_helper.o \
> drm_atomic_state_helper.o drm_damage_helper.o \
> - drm_format_helper.o drm_self_refresh_helper.o
> + drm_format_helper.o drm_self_refresh_helper.o drm_afbc.o
Just a quick drive-by:
- you can't put this into helpers and call from core code. This should be
core code. Also, I'd have just stuffed it into drm_format.c.
- If you want to keep your separate file, please include it in the doc
template, next to the format handling functions.
>
> drm_kms_helper-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o
> drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o
> diff --git a/drivers/gpu/drm/drm_afbc.c b/drivers/gpu/drm/drm_afbc.c
> new file mode 100644
> index 000000000000..f308c4719546
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_afbc.c
> @@ -0,0 +1,84 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * (C) 2019 Collabora Ltd.
> + *
> + * author: Andrzej Pietrasiewicz <andrzej.p at collabora.com>
> + *
> + */
> +#include <linux/module.h>
> +
> +#include <drm/drm_afbc.h>
> +#include <drm/drm_device.h>
> +#include <drm/drm_fourcc.h>
> +#include <drm/drm_gem.h>
> +#include <drm/drm_mode.h>
> +#include <drm/drm_print.h>
> +
> +/**
> + * drm_afbc_get_superblk_wh - extract afbc block width/height from modifier
> + * @modifier: the modifier to be looked at
> + * @w: address of a place to store the block width
> + * @h: address of a place to store the block height
> + *
> + * Returns: true if the modifier describes a supported block size
> + */
> +bool drm_afbc_get_superblk_wh(u64 modifier, u32 *w, u32 *h)
> +{
> + switch (modifier & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK) {
> + case AFBC_FORMAT_MOD_BLOCK_SIZE_16x16:
> + *w = 16;
> + *h = 16;
> + break;
> + case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8:
> + *w = 32;
> + *h = 8;
> + break;
> + case AFBC_FORMAT_MOD_BLOCK_SIZE_64x4:
> + /* fall through */
> + case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8_64x4:
> + /* fall through */
> + default:
> + DRM_DEBUG_KMS("Invalid AFBC_FORMAT_MOD_BLOCK_SIZE: %lld.\n",
> + modifier & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK);
> + return false;
> + }
> + return true;
> +}
> +EXPORT_SYMBOL_GPL(drm_afbc_get_superblk_wh);
> +
> +/**
> + * drm_afbc_get_parameters - extract afbc parameters from mode command
> + * @mode_cmd: mode command to be looked at
> + * @afbc: address of a struct to be filled in
> + */
> +void drm_afbc_get_parameters(const struct drm_mode_fb_cmd2 *mode_cmd,
> + struct drm_afbc *afbc)
> +{
> + drm_afbc_get_superblk_wh(mode_cmd->modifier[0],
> + &afbc->tile_w, &afbc->tile_h);
> + afbc->width = mode_cmd->pitches[0];
> + afbc->height =
> + DIV_ROUND_UP(mode_cmd->height, afbc->tile_h) * afbc->tile_h;
> + afbc->offset = mode_cmd->offsets[0];
> +}
> +EXPORT_SYMBOL(drm_afbc_get_parameters);
> +
> +/**
> + * drm_is_afbc - test if the modifier describes an afbc buffer
> + * @modifier - modifier to be tested
> + *
> + * Returns: true if the modifier describes an afbc buffer
> + */
> +bool drm_is_afbc(u64 modifier)
> +{
> + /* is it ARM AFBC? */
> + if ((modifier & DRM_FORMAT_MOD_ARM_AFBC(0)) == 0)
> + return false;
> +
> + /* Block size must be known */
> + if ((modifier & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK) == 0)
> + return false;
> +
> + return true;
> +}
> +EXPORT_SYMBOL_GPL(drm_is_afbc);
> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> index c630064ccf41..8d9f197cc0ab 100644
> --- a/drivers/gpu/drm/drm_fourcc.c
> +++ b/drivers/gpu/drm/drm_fourcc.c
> @@ -27,6 +27,7 @@
> #include <linux/export.h>
> #include <linux/kernel.h>
>
> +#include <drm/drm_afbc.h>
> #include <drm/drm_device.h>
> #include <drm/drm_fourcc.h>
>
> @@ -322,8 +323,14 @@ drm_get_format_info(struct drm_device *dev,
> {
> const struct drm_format_info *info = NULL;
>
> - if (dev->mode_config.funcs->get_format_info)
> - info = dev->mode_config.funcs->get_format_info(mode_cmd);
> + /* bypass driver callback if afbc */
> + if (!drm_is_afbc(mode_cmd->modifier[0]))
> + if (dev->mode_config.funcs->get_format_info) {
> + const struct drm_mode_config_funcs *funcs;
> +
> + funcs = dev->mode_config.funcs;
> + info = funcs->get_format_info(mode_cmd);
> + }
>
> if (!info)
> info = drm_format_info(mode_cmd->pixel_format);
> diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
> index 57564318ceea..303eea624a02 100644
> --- a/drivers/gpu/drm/drm_framebuffer.c
> +++ b/drivers/gpu/drm/drm_framebuffer.c
> @@ -23,6 +23,7 @@
> #include <linux/export.h>
> #include <linux/uaccess.h>
>
> +#include <drm/drm_afbc.h>
> #include <drm/drm_atomic.h>
> #include <drm/drm_atomic_uapi.h>
> #include <drm/drm_auth.h>
> @@ -31,6 +32,7 @@
> #include <drm/drm_file.h>
> #include <drm/drm_fourcc.h>
> #include <drm/drm_framebuffer.h>
> +#include <drm/drm_gem.h>
> #include <drm/drm_print.h>
> #include <drm/drm_util.h>
>
> @@ -168,7 +170,69 @@ static int fb_plane_height(int height,
> return DIV_ROUND_UP(height, format->vsub);
> }
>
> +static int afbc_check(struct drm_file *file_priv,
> + const struct drm_mode_fb_cmd2 *r, int i,
> + const struct drm_format_info *info)
> +{
> + struct drm_gem_object *obj;
> + int bpp = info->cpp[0] * 8;
> + int tiles;
> + u32 w, h, height, tile_sz, afbc_size;
> + int result = 0;
> +
> + if (i) {
> + DRM_DEBUG_KMS("AFBC supported only for plane 0\n");
> +
> + return 1;
> + }
> +
> + /* get tile w/h */
> + if (!drm_afbc_get_superblk_wh(r->modifier[0], &w, &h))
> + return 1;
> +
> + /* pitch must be divisible by tile width */
> + if (r->pitches[0] % w) {
> + DRM_DEBUG_KMS("Invalid pitch for plane %d\n", i);
> +
> + return 1;
> + }
> +
> + obj = drm_gem_object_lookup(file_priv, r->handles[0]);
I think this is a bit ugly ... I'd split this into a new
framebuffer_check_post() function which is called after fb_create, at that
point you do have the objects already looked up.
Also I suggested that this could be done as a helper implementation for
fb_create, wrapping it around the default gem implementation. That way you
could keep all the afbc stuff in helpers entirely (but drivers could screw
things up, so there's a tradeoff).
What's definitely not ok is calling drm_gem_object_lookup unconditionally
from core code here. For consistency I think the helper approach would be
good, since currently the size related checks are done in
drm_gem_fb_create() - i.e. in the helpers, not in core. Otoh having checks
split like this is also ugly, so maybe we should have a
framebuffer_check_post for everyone, and move all the size checks into
core (not just for afbc).
-Daniel
> + if (!obj) {
> + DRM_DEBUG_KMS("Failed to lookup GEM object\n");
> +
> + return 1;
> + }
> +
> + /* estimate height based on tile size and height from userspace */
> + height = DIV_ROUND_UP(r->height, h) * h;
> +
> + tiles = (r->pitches[0] / w) * (height / h);
> + afbc_size = ALIGN(tiles * AFBC_HEADER_SIZE, AFBC_SUPERBLK_ALIGNMENT);
> +
> + tile_sz = (bpp * w * h) / BITS_PER_BYTE;
> + afbc_size += tiles * ALIGN(tile_sz, AFBC_SUPERBLK_ALIGNMENT);
> +
> + result = obj->size < afbc_size;
> +
> + drm_gem_object_put_unlocked(obj);
> +
> + return result;
> +}
> +
> +static int modifier_check(struct drm_file *file_priv,
> + const struct drm_mode_fb_cmd2 *r, int i,
> + const struct drm_format_info *info)
> +{
> + /* non-afbc format */
> + if (!drm_is_afbc(r->modifier[i]))
> + return 0;
> +
> + return afbc_check(file_priv, r, i, info);
> +}
> +
> static int framebuffer_check(struct drm_device *dev,
> + struct drm_file *file_priv,
> const struct drm_mode_fb_cmd2 *r)
> {
> const struct drm_format_info *info;
> @@ -204,6 +268,9 @@ static int framebuffer_check(struct drm_device *dev,
> unsigned int block_size = info->char_per_block[i];
> u64 min_pitch = drm_format_info_min_pitch(info, i, width);
>
> + if (drm_is_afbc(r->modifier[i]))
> + block_size = 0;
> +
> if (!block_size && (r->modifier[i] == DRM_FORMAT_MOD_LINEAR)) {
> DRM_DEBUG_KMS("Format requires non-linear modifier for plane %d\n", i);
> return -EINVAL;
> @@ -253,6 +320,8 @@ static int framebuffer_check(struct drm_device *dev,
> break;
>
> default:
> + if (modifier_check(file_priv, r, i, info))
> + return -EINVAL;
> break;
> }
> }
> @@ -317,7 +386,7 @@ drm_internal_framebuffer_create(struct drm_device *dev,
> return ERR_PTR(-EINVAL);
> }
>
> - ret = framebuffer_check(dev, r);
> + ret = framebuffer_check(dev, file_priv, r);
> if (ret)
> return ERR_PTR(ret);
>
> diff --git a/include/drm/drm_afbc.h b/include/drm/drm_afbc.h
> new file mode 100644
> index 000000000000..fb4d4549f77e
> --- /dev/null
> +++ b/include/drm/drm_afbc.h
> @@ -0,0 +1,35 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * (C) 2019 Collabora Ltd.
> + *
> + * author: Andrzej Pietrasiewicz <andrzej.p at collabora.com>
> + *
> + */
> +#ifndef __DRM_AFBC_H__
> +#define __DRM_AFBC_H__
> +
> +#include <linux/types.h>
> +
> +struct drm_device;
> +struct drm_mode_fb_cmd2;
> +struct drm_gem_object;
> +
> +struct drm_afbc {
> + u32 tile_w;
> + u32 tile_h;
> + u32 width;
> + u32 height;
> + u32 offset;
> +};
> +
> +#define AFBC_HEADER_SIZE 16
> +#define AFBC_SUPERBLK_ALIGNMENT 128
> +
> +bool drm_afbc_get_superblk_wh(u64 modifier, u32 *w, u32 *h);
> +
> +void drm_afbc_get_parameters(const struct drm_mode_fb_cmd2 *mode_cmd,
> + struct drm_afbc *afbc);
> +
> +bool drm_is_afbc(u64 modifier);
> +
> +#endif /* __DRM_AFBC_H__ */
> --
> 2.17.1
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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