Re: [PATCH] drm/rockchip: Add AFBC support

[Brian Starkey]

Hi Andrzej,

Thanks for the patch, it's nice to see another AFBC implementation
coming in.

For future versions, could you please Cc ayan.halder@xxxxxxx? It would
have been nice to have someone @arm.com on patches which use/impact
Arm modifiers. Sadly I don't know how to make get_maintainer.pl help
with that.

Some more comments below.

On Mon, Sep 23, 2019 at 02:20:13PM +0200, Andrzej Pietrasiewicz wrote:
> From: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
> 
> AFBC is a proprietary lossless image compression protocol and format.
> It helps reduce memory bandwidth of the graphics pipeline operations.
> This, in turn, improves power efficiency.
> 
> Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
> [locking improvements]
> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>
> [squashing the above, commit message and Rockchip AFBC modifier]
> Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/rockchip/rockchip_drm_fb.c  | 27 ++++++
>  drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 94 ++++++++++++++++++++-
>  drivers/gpu/drm/rockchip/rockchip_drm_vop.h | 12 +++
>  drivers/gpu/drm/rockchip/rockchip_vop_reg.c | 18 ++++
>  include/uapi/drm/drm_fourcc.h               |  3 +
>  5 files changed, 151 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
> index 64ca87cf6d50..5178939a9c29 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
> @@ -24,6 +24,27 @@ static const struct drm_framebuffer_funcs rockchip_drm_fb_funcs = {
>  	.dirty	       = drm_atomic_helper_dirtyfb,
>  };
>  
> +static int
> +rockchip_verify_afbc_mod(struct drm_device *dev,
> +			 const struct drm_mode_fb_cmd2 *mode_cmd)
> +{
> +	if (mode_cmd->modifier[0] &
> +	    ~DRM_FORMAT_MOD_ARM_AFBC(AFBC_FORMAT_MOD_ROCKCHIP)) {
> +		DRM_DEV_ERROR(dev->dev,
> +			      "Unsupported format modifier 0x%llx\n",
> +			      mode_cmd->modifier[0]);
> +		return -EINVAL;
> +	}
> +
> +	if (mode_cmd->width > 2560) {
> +		DRM_DEV_ERROR(dev->dev,
> +			      "Unsupported width %d\n", mode_cmd->width);
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
>  static struct drm_framebuffer *
>  rockchip_fb_alloc(struct drm_device *dev, const struct drm_mode_fb_cmd2 *mode_cmd,
>  		  struct drm_gem_object **obj, unsigned int num_planes)
> @@ -32,6 +53,12 @@ rockchip_fb_alloc(struct drm_device *dev, const struct drm_mode_fb_cmd2 *mode_cm
>  	int ret;
>  	int i;
>  
> +	if (mode_cmd->modifier[0]) {
> +		ret = rockchip_verify_afbc_mod(dev, mode_cmd);
> +		if (ret)
> +			return ERR_PTR(ret);
> +	}
> +
>  	fb = kzalloc(sizeof(*fb), GFP_KERNEL);
>  	if (!fb)
>  		return ERR_PTR(-ENOMEM);
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> index 21b68eea46cc..50bf214d21da 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> @@ -46,6 +46,13 @@
>  		vop_reg_set(vop, &win->phy->scl->ext->name, \
>  			    win->base, ~0, v, #name)
>  
> +#define VOP_AFBC_SET(x, name, v) \
> +	do { \
> +		if (vop->data->afbc) \
> +			vop_reg_set(vop, &vop->data->afbc->name, \
> +				0, ~0, v, #name); \
> +	} while (0)
> +
>  #define VOP_WIN_YUV2YUV_SET(vop, win_yuv2yuv, name, v) \
>  	do { \
>  		if (win_yuv2yuv && win_yuv2yuv->name.mask) \
> @@ -123,6 +130,8 @@ struct vop {
>  	struct drm_device *drm_dev;
>  	bool is_enabled;
>  
> +	struct vop_win *afbc_win;
> +
>  	struct completion dsp_hold_completion;
>  
>  	/* protected by dev->event_lock */
> @@ -245,6 +254,30 @@ static bool has_rb_swapped(uint32_t format)
>  	}
>  }
>  
> +#define AFBC_FMT_RGB565        0x0
> +#define AFBC_FMT_U8U8U8U8      0x5
> +#define AFBC_FMT_U8U8U8        0x4
> +
> +static int vop_convert_afbc_format(uint32_t format)
> +{

It would be great if you are able to follow the guidance Arm published
here: https://www.kernel.org/doc/html/latest/gpu/afbc.html, which will
help ensure interoperability and compatibility between different
devices/drivers. Hopefully it doesn't limit some use-cases for you -
if it does, let's discuss them.

Specifically, please take a look at the format list there. Some of
your formats below are not on the preferred interop list:

> +	switch (format) {
> +	case DRM_FORMAT_XRGB8888:

XRGB8888: Not preferred, as encoding the X channel is a waste of bits

> +	case DRM_FORMAT_ARGB8888:

ARGB8888: Not preferred as the channel order prevents YTR

> +	case DRM_FORMAT_XBGR8888:

XBGR8888: Not preferred, as encoding the X channel is a waste of bits

> +	case DRM_FORMAT_ABGR8888:
> +		return AFBC_FMT_U8U8U8U8;
> +	case DRM_FORMAT_RGB888:

RGB888: Not preferred as the channel order prevents YTR

> +	case DRM_FORMAT_BGR888:
> +		return AFBC_FMT_U8U8U8;
> +	case DRM_FORMAT_RGB565:

RGB565: Not preferred as the channel order prevents YTR

> +	case DRM_FORMAT_BGR565:
> +		return AFBC_FMT_RGB565;
> +	default:
> +		DRM_ERROR("unsupported afbc format[%08x]\n", format);
> +		return -EINVAL;
> +	}
> +}
> +
>  static enum vop_data_format vop_convert_format(uint32_t format)
>  {
>  	switch (format) {
> @@ -587,10 +620,16 @@ static int vop_enable(struct drm_crtc *crtc)
>  
>  		vop_win_disable(vop, win);
>  	}
> -	spin_unlock(&vop->reg_lock);
> +
> +	if (vop->data->afbc) {
> +		VOP_AFBC_SET(vop, enable, 0);
> +		vop->afbc_win = NULL;
> +	}
>  
>  	vop_cfg_done(vop);
>  
> +	spin_unlock(&vop->reg_lock);
> +
>  	/*
>  	 * At here, vop clock & iommu is enable, R/W vop regs would be safe.
>  	 */
> @@ -719,6 +758,32 @@ static int vop_plane_atomic_check(struct drm_plane *plane,
>  		return -EINVAL;
>  	}
>  
> +	if (fb->modifier & DRM_FORMAT_MOD_ARM_AFBC(AFBC_FORMAT_MOD_ROCKCHIP)) {
> +		struct vop *vop = to_vop(crtc);
> +
> +		if (!vop->data->afbc) {
> +			DRM_ERROR("VOP does not support AFBC\n");
> +			return -EINVAL;
> +		}
> +
> +		ret = vop_convert_afbc_format(fb->format->format);
> +		if (ret < 0)
> +			return ret;
> +
> +		if (state->src.x1 || state->src.y1) {
> +			DRM_ERROR("AFBC does not support offset display\n");
> +			DRM_ERROR("xpos=%d, ypos=%d, offset=%d\n",
> +				state->src.x1, state->src.y1, fb->offsets[0]);
> +			return -EINVAL;
> +		}
> +
> +		if (state->rotation && state->rotation != DRM_MODE_ROTATE_0) {
> +			DRM_ERROR("AFBC does not support rotation\n");
> +			DRM_ERROR("rotation=%d\n", state->rotation);
> +			return -EINVAL;
> +		}

It may be a good idea to check your framebuffer size, as the required
framebuffer size is different for AFBC. You can refer to mali-dp for
the calculations - perhaps even share the code.

> +	}
> +
>  	return 0;
>  }
>  
> @@ -732,6 +797,9 @@ static void vop_plane_atomic_disable(struct drm_plane *plane,
>  	if (!old_state->crtc)
>  		return;
>  
> +	if (vop->afbc_win == vop_win)
> +		vop->afbc_win = NULL;
> +
>  	spin_lock(&vop->reg_lock);
>  
>  	vop_win_disable(vop, win);
> @@ -774,6 +842,9 @@ static void vop_plane_atomic_update(struct drm_plane *plane,
>  	if (WARN_ON(!vop->is_enabled))
>  		return;
>  
> +	if (vop->afbc_win == vop_win)
> +		vop->afbc_win = NULL;
> +
>  	if (!state->visible) {
>  		vop_plane_atomic_disable(plane, old_state);
>  		return;
> @@ -808,6 +879,20 @@ static void vop_plane_atomic_update(struct drm_plane *plane,
>  
>  	spin_lock(&vop->reg_lock);
>  
> +	if (fb->modifier & DRM_FORMAT_MOD_ARM_AFBC(AFBC_FORMAT_MOD_ROCKCHIP)) {
> +		int afbc_format = vop_convert_afbc_format(fb->format->format);
> +
> +		VOP_AFBC_SET(vop, format, afbc_format | 1 << 4);
> +		VOP_AFBC_SET(vop, hreg_block_split, 0);
> +		VOP_AFBC_SET(vop, win_sel, win_index);
> +		VOP_AFBC_SET(vop, hdr_ptr, dma_addr);
> +		VOP_AFBC_SET(vop, pic_size, act_info);
> +
> +		vop->afbc_win = vop_win;
> +
> +		pr_info("AFBC on plane %s\n", plane->name);
> +	}
> +
>  	VOP_WIN_SET(vop, win, format, format);
>  	VOP_WIN_SET(vop, win, yrgb_vir, DIV_ROUND_UP(fb->pitches[0], 4));
>  	VOP_WIN_SET(vop, win, yrgb_mst, dma_addr);
> @@ -1163,6 +1248,7 @@ static void vop_crtc_atomic_flush(struct drm_crtc *crtc,
>  
>  	spin_lock(&vop->reg_lock);
>  
> +	VOP_AFBC_SET(vop, enable, vop->afbc_win ? 0x1 : 0);
>  	vop_cfg_done(vop);
>  
>  	spin_unlock(&vop->reg_lock);
> @@ -1471,7 +1557,8 @@ static int vop_create_crtc(struct vop *vop)
>  					       0, &vop_plane_funcs,
>  					       win_data->phy->data_formats,
>  					       win_data->phy->nformats,
> -					       NULL, win_data->type, NULL);
> +					       win_data->phy->format_modifiers,
> +					       win_data->type, NULL);
>  		if (ret) {
>  			DRM_DEV_ERROR(vop->dev, "failed to init plane %d\n",
>  				      ret);
> @@ -1511,7 +1598,8 @@ static int vop_create_crtc(struct vop *vop)
>  					       &vop_plane_funcs,
>  					       win_data->phy->data_formats,
>  					       win_data->phy->nformats,
> -					       NULL, win_data->type, NULL);
> +					       win_data->phy->format_modifiers,
> +					       win_data->type, NULL);
>  		if (ret) {
>  			DRM_DEV_ERROR(vop->dev, "failed to init overlay %d\n",
>  				      ret);
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.h b/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
> index 2149a889c29d..dc8b12025269 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
> @@ -77,6 +77,16 @@ struct vop_misc {
>  	struct vop_reg global_regdone_en;
>  };
>  
> +struct vop_afbc {
> +	struct vop_reg enable;
> +	struct vop_reg win_sel;
> +	struct vop_reg format;
> +	struct vop_reg hreg_block_split;
> +	struct vop_reg pic_size;
> +	struct vop_reg hdr_ptr;
> +	struct vop_reg rstn;
> +};
> +
>  struct vop_intr {
>  	const int *intrs;
>  	uint32_t nintrs;
> @@ -128,6 +138,7 @@ struct vop_win_phy {
>  	const struct vop_scl_regs *scl;
>  	const uint32_t *data_formats;
>  	uint32_t nformats;
> +	const uint64_t *format_modifiers;
>  
>  	struct vop_reg enable;
>  	struct vop_reg gate;
> @@ -169,6 +180,7 @@ struct vop_data {
>  	const struct vop_output *output;
>  	const struct vop_win_yuv2yuv_data *win_yuv2yuv;
>  	const struct vop_win_data *win;
> +	const struct vop_afbc *afbc;
>  	unsigned int win_size;
>  
>  #define VOP_FEATURE_OUTPUT_RGB10	BIT(0)
> diff --git a/drivers/gpu/drm/rockchip/rockchip_vop_reg.c b/drivers/gpu/drm/rockchip/rockchip_vop_reg.c
> index 7b9c74750f6d..e9ff0c43c396 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_vop_reg.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_vop_reg.c
> @@ -30,6 +30,12 @@
>  #define VOP_REG_MASK_SYNC(off, _mask, _shift) \
>  		_VOP_REG(off, _mask, _shift, true, false)
>  
> +static const uint64_t format_modifiers_afbc[] = {
> +	DRM_FORMAT_MOD_ARM_AFBC(AFBC_FORMAT_MOD_ROCKCHIP),
> +	DRM_FORMAT_MOD_LINEAR,
> +	DRM_FORMAT_MOD_INVALID
> +};
> +
>  static const uint32_t formats_win_full[] = {
>  	DRM_FORMAT_XRGB8888,
>  	DRM_FORMAT_ARGB8888,
> @@ -667,6 +673,7 @@ static const struct vop_win_phy rk3368_win01_data = {
>  	.scl = &rk3288_win_full_scl,
>  	.data_formats = formats_win_full,
>  	.nformats = ARRAY_SIZE(formats_win_full),
> +	.format_modifiers = format_modifiers_afbc,

I may have missed something, but don't you need to implement the
format_mod_supported hook on the plane to expose the modifiers to
userspace?

>  	.enable = VOP_REG(RK3368_WIN0_CTRL0, 0x1, 0),
>  	.format = VOP_REG(RK3368_WIN0_CTRL0, 0x7, 1),
>  	.rb_swap = VOP_REG(RK3368_WIN0_CTRL0, 0x1, 12),
> @@ -758,6 +765,16 @@ static const struct vop_data rk3366_vop = {
>  	.win_size = ARRAY_SIZE(rk3368_vop_win_data),
>  };
>  
> +static const struct vop_afbc rk3399_afbc = {
> +	.rstn = VOP_REG(RK3399_AFBCD0_CTRL, 0x1, 3),
> +	.enable = VOP_REG(RK3399_AFBCD0_CTRL, 0x1, 0),
> +	.win_sel = VOP_REG(RK3399_AFBCD0_CTRL, 0x3, 1),
> +	.format = VOP_REG(RK3399_AFBCD0_CTRL, 0x1f, 16),
> +	.hreg_block_split = VOP_REG(RK3399_AFBCD0_CTRL, 0x1, 21),
> +	.hdr_ptr = VOP_REG(RK3399_AFBCD0_HDR_PTR, 0xffffffff, 0),
> +	.pic_size = VOP_REG(RK3399_AFBCD0_PIC_SIZE, 0xffffffff, 0),
> +};
> +
>  static const struct vop_output rk3399_output = {
>  	.dp_pin_pol = VOP_REG(RK3399_DSP_CTRL1, 0xf, 16),
>  	.rgb_pin_pol = VOP_REG(RK3368_DSP_CTRL1, 0xf, 16),
> @@ -808,6 +825,7 @@ static const struct vop_data rk3399_vop_big = {
>  	.modeset = &rk3288_modeset,
>  	.output = &rk3399_output,
>  	.misc = &rk3368_misc,
> +	.afbc = &rk3399_afbc,
>  	.win = rk3368_vop_win_data,
>  	.win_size = ARRAY_SIZE(rk3368_vop_win_data),
>  	.win_yuv2yuv = rk3399_vop_big_win_yuv2yuv_data,
> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
> index 3feeaa3f987a..ba6caf06c824 100644
> --- a/include/uapi/drm/drm_fourcc.h
> +++ b/include/uapi/drm/drm_fourcc.h
> @@ -742,6 +742,9 @@ extern "C" {
>   */
>  #define AFBC_FORMAT_MOD_BCH     (1ULL << 11)
>  
> +#define AFBC_FORMAT_MOD_ROCKCHIP \
> +	(AFBC_FORMAT_MOD_BLOCK_SIZE_16x16 | AFBC_FORMAT_MOD_SPARSE)
> +

As Neil said, this seems redundant. If you would like the convenience
macro, stick it in the Rockchip driver rather than UAPI.

Also, if your hardware is able to support YTR, I would recommend
enabling it.

Best regards,
-Brian

>  /*
>   * Allwinner tiled modifier
>   *
> -- 
> 2.17.1
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/dri-devel