Messages in this thread | | | Date | Thu, 11 Mar 2021 12:10:42 +0000 | From | Paul Cercueil <> | Subject | Re: [PATCH v2 5/5] drm/ingenic: Add option to alloc cached GEM buffers |
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Le jeu. 11 mars 2021 à 10:27, Hillf Danton <hdanton@sina.com> a écrit : > On Wed, 10 Mar 2021 19:01:01 +0000 Paul Cercueil wrote: >> Le lun. 8 mars 2021 11:47, Hillf Danton <hdanton@sina.com> a crit : >>> On Sun, 7 Mar 2021 20:28:35 +0000 Paul Cercueil wrote: >>>> With the module parameter ingenic-drm.cached_gem_buffers, it is >>>> possible >>>> to specify that we want GEM buffers backed by non-coherent >>>> memory. >>>> >>>> This dramatically speeds up software rendering on Ingenic SoCs, >>>> even for >>>> tasks where write-combine memory should in theory be faster (e.g. >>>> simple >>>> blits). >>> >>> Wondering if it is due to the tricks at [1]. >>> >>> If so, is dma_alloc_noncoherent() necessary in this patchset? >> >> You confuse non-contiguous with non-coherent, which are two different >> things. > > You misunderstood me. From [1] we know coherent caching is arch thing, > so your proposal is not mandatory on ARM IMHO - what baffles me is > noncoherent back memory can speed up device, coherent ot not, > regardless > of arch. Can you point me to the reasons behind your speedup?
Well, I did write in the cover letter that it would help *some* SoCs, so it is not meant to be a default setting. As you can see in the last patch, it is opt-in. Ingenic SoCs are MIPS SoCs, btw.
One thing I should add is that this speeds up *software* rendering (vs. write-combine). It makes perfect sense that it speeds up things like alpha-blending, but I can't explain why it speeds up standard blits. My guess is that cache line invalidation is just extremely fast on this SoC.
-Paul
>> >> Cheers, >> -Paul >> >>> Christoph can you give us a concise lesson on noncoherency covering >>> at least >>> noncoherent device, noncoherent memory(used in this work), no >>> coherent >>> caching(in [1]), their links to speedup, and the thumb rule to >>> handle >>> noncoherency in workdays. It feels toe curling every time I see >>> noncoherence >>> going downtown with speedup hand in hand. >>> >>> [1] Subject: [PATCH 6/6] media: uvcvideo: Use >>> dma_alloc_noncontiguos >>> API >>> https://lore.kernel.org/lkml/20210301085236.947011-7-hch@lst.de/#t >>> >>>> >>>> Leave it disabled by default, since it is specific to one >>>> use-case >>>> (software rendering). >>>> >>>> v2: Rework code to work with new DRM APIs regarding plane states >>>> >>>> Signed-off-by: Paul Cercueil <paul@crapouillou.net> >>>> --- >>>> drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 49 >>>> ++++++++++++++++++++++- >>>> drivers/gpu/drm/ingenic/ingenic-drm.h | 4 ++ >>>> drivers/gpu/drm/ingenic/ingenic-ipu.c | 14 ++++++- >>>> 3 files changed, 63 insertions(+), 4 deletions(-) >>>> >>>> diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c >>>> b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c >>>> index d60e1eefc9d1..ba1ac0fcda74 100644 >>>> --- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c >>>> +++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c >>>> @@ -9,6 +9,7 @@ >>>> #include <linux/component.h> >>>> #include <linux/clk.h> >>>> #include <linux/dma-mapping.h> >>>> +#include <linux/io.h> >>>> #include <linux/module.h> >>>> #include <linux/mutex.h> >>>> #include <linux/of_device.h> >>>> @@ -23,6 +24,7 @@ >>>> #include <drm/drm_color_mgmt.h> >>>> #include <drm/drm_crtc.h> >>>> #include <drm/drm_crtc_helper.h> >>>> +#include <drm/drm_damage_helper.h> >>>> #include <drm/drm_drv.h> >>>> #include <drm/drm_gem_cma_helper.h> >>>> #include <drm/drm_fb_cma_helper.h> >>>> @@ -99,6 +101,11 @@ struct ingenic_drm { >>>> struct notifier_block clock_nb; >>>> }; >>>> >>>> +static bool ingenic_drm_cached_gem_buf; >>>> +module_param_named(cached_gem_buffers, >>>> ingenic_drm_cached_gem_buf, >>>> bool, 0400); >>>> +MODULE_PARM_DESC(cached_gem_buffers, >>>> + "Enable fully cached GEM buffers [default=false]"); >>>> + >>>> static bool ingenic_drm_writeable_reg(struct device *dev, >>>> unsigned >>>> int reg) >>>> { >>>> switch (reg) { >>>> @@ -410,6 +417,8 @@ static int >>>> ingenic_drm_plane_atomic_check(struct drm_plane *plane, >>>> old_plane_state->fb->format->format != >>>> new_plane_state->fb->format->format)) >>>> crtc_state->mode_changed = true; >>>> >>>> + drm_atomic_helper_check_plane_damage(state, new_plane_state); >>>> + >>>> return 0; >>>> } >>>> >>>> @@ -541,10 +550,20 @@ static void >>>> ingenic_drm_update_palette(struct >>>> ingenic_drm *priv, >>>> } >>>> } >>>> >>>> +void ingenic_drm_sync_data(struct device *dev, >>>> + struct drm_plane_state *old_state, >>>> + struct drm_plane_state *state) >>>> +{ >>>> + if (ingenic_drm_cached_gem_buf) >>>> + drm_gem_cma_sync_data(dev, old_state, state); >>>> +} >>>> + >>>> static void ingenic_drm_plane_atomic_update(struct drm_plane >>>> *plane, >>>> struct drm_atomic_state *state) >>>> { >>>> struct ingenic_drm *priv = drm_device_get_priv(plane->dev); >>>> + struct drm_plane_state *oldstate = >>>> drm_atomic_get_old_plane_state(state, >>>> + plane); >>>> struct drm_plane_state *newstate = >>>> drm_atomic_get_new_plane_state(state, >>>> plane); >>>> struct drm_crtc_state *crtc_state; >>>> @@ -554,6 +573,8 @@ static void >>>> ingenic_drm_plane_atomic_update(struct drm_plane *plane, >>>> u32 fourcc; >>>> >>>> if (newstate && newstate->fb) { >>>> + ingenic_drm_sync_data(priv->dev, oldstate, newstate); >>>> + >>>> crtc_state = newstate->crtc->state; >>>> >>>> addr = drm_fb_cma_get_gem_addr(newstate->fb, newstate, 0); >>>> @@ -743,6 +764,26 @@ static void >>>> ingenic_drm_disable_vblank(struct >>>> drm_crtc *crtc) >>>> regmap_update_bits(priv->map, JZ_REG_LCD_CTRL, >>>> JZ_LCD_CTRL_EOF_IRQ, 0); >>>> } >>>> >>>> +static struct drm_framebuffer * >>>> +ingenic_drm_gem_fb_create(struct drm_device *dev, struct >>>> drm_file >>>> *file, >>>> + const struct drm_mode_fb_cmd2 *mode_cmd) >>>> +{ >>>> + if (ingenic_drm_cached_gem_buf) >>>> + return drm_gem_fb_create_with_dirty(dev, file, mode_cmd); >>>> + >>>> + return drm_gem_fb_create(dev, file, mode_cmd); >>>> +} >>>> + >>>> +static int ingenic_drm_gem_cma_dumb_create(struct drm_file >>>> *file_priv, >>>> + struct drm_device *drm, >>>> + struct drm_mode_create_dumb *args) >>>> +{ >>>> + if (ingenic_drm_cached_gem_buf) >>>> + return drm_gem_cma_dumb_create_noncoherent(file_priv, drm, >>>> args); >>>> + >>>> + return drm_gem_cma_dumb_create(file_priv, drm, args); >>>> +} >>>> + >>>> DEFINE_DRM_GEM_CMA_FOPS(ingenic_drm_fops); >>>> >>>> static const struct drm_driver ingenic_drm_driver_data = { >>>> @@ -755,7 +796,7 @@ static const struct drm_driver >>>> ingenic_drm_driver_data = { >>>> .patchlevel = 0, >>>> >>>> .fops = &ingenic_drm_fops, >>>> - DRM_GEM_CMA_DRIVER_OPS, >>>> >>>> >>>> + DRM_GEM_CMA_DRIVER_OPS_WITH_DUMB_CREATE(ingenic_drm_gem_cma_dumb_create), >>>> >>>> .irq_handler = ingenic_drm_irq_handler, >>>> }; >>>> @@ -805,7 +846,7 @@ static const struct drm_encoder_helper_funcs >>>> ingenic_drm_encoder_helper_funcs = >>>> }; >>>> >>>> static const struct drm_mode_config_funcs >>>> ingenic_drm_mode_config_funcs = { >>>> - .fb_create = drm_gem_fb_create, >>>> + .fb_create = ingenic_drm_gem_fb_create, >>>> .output_poll_changed = drm_fb_helper_output_poll_changed, >>>> .atomic_check = drm_atomic_helper_check, >>>> .atomic_commit = drm_atomic_helper_commit, >>>> @@ -962,6 +1003,8 @@ static int ingenic_drm_bind(struct device >>>> *dev, bool has_components) >>>> return ret; >>>> } >>>> >>>> + drm_plane_enable_fb_damage_clips(&priv->f1); >>>> + >>>> drm_crtc_helper_add(&priv->crtc, >>>> &ingenic_drm_crtc_helper_funcs); >>>> >>>> ret = drm_crtc_init_with_planes(drm, &priv->crtc, primary, >>>> @@ -990,6 +1033,8 @@ static int ingenic_drm_bind(struct device >>>> *dev, bool has_components) >>>> return ret; >>>> } >>>> >>>> + drm_plane_enable_fb_damage_clips(&priv->f0); >>>> + >>>> if (IS_ENABLED(CONFIG_DRM_INGENIC_IPU) && has_components) { >>>> ret = component_bind_all(dev, drm); >>>> if (ret) { >>>> diff --git a/drivers/gpu/drm/ingenic/ingenic-drm.h >>>> b/drivers/gpu/drm/ingenic/ingenic-drm.h >>>> index 1b4347f7f084..b6bca356e024 100644 >>>> --- a/drivers/gpu/drm/ingenic/ingenic-drm.h >>>> +++ b/drivers/gpu/drm/ingenic/ingenic-drm.h >>>> @@ -185,6 +185,10 @@ void ingenic_drm_plane_config(struct device >>>> *dev, >>>> struct drm_plane *plane, u32 fourcc); >>>> void ingenic_drm_plane_disable(struct device *dev, struct >>>> drm_plane *plane); >>>> >>>> +void ingenic_drm_sync_data(struct device *dev, >>>> + struct drm_plane_state *old_state, >>>> + struct drm_plane_state *state); >>>> + >>>> extern struct platform_driver *ingenic_ipu_driver_ptr; >>>> >>>> #endif /* DRIVERS_GPU_DRM_INGENIC_INGENIC_DRM_H */ >>>> diff --git a/drivers/gpu/drm/ingenic/ingenic-ipu.c >>>> b/drivers/gpu/drm/ingenic/ingenic-ipu.c >>>> index 5ae6adab8306..7826eab044ba 100644 >>>> --- a/drivers/gpu/drm/ingenic/ingenic-ipu.c >>>> +++ b/drivers/gpu/drm/ingenic/ingenic-ipu.c >>>> @@ -20,6 +20,7 @@ >>>> >>>> #include <drm/drm_atomic.h> >>>> #include <drm/drm_atomic_helper.h> >>>> +#include <drm/drm_damage_helper.h> >>>> #include <drm/drm_drv.h> >>>> #include <drm/drm_fb_cma_helper.h> >>>> #include <drm/drm_fourcc.h> >>>> @@ -285,6 +286,8 @@ static void >>>> ingenic_ipu_plane_atomic_update(struct drm_plane *plane, >>>> struct drm_atomic_state *state) >>>> { >>>> struct ingenic_ipu *ipu = plane_to_ingenic_ipu(plane); >>>> + struct drm_plane_state *oldstate = >>>> drm_atomic_get_old_plane_state(state, >>>> + plane); >>>> struct drm_plane_state *newstate = >>>> drm_atomic_get_new_plane_state(state, >>>> plane); >>>> const struct drm_format_info *finfo; >>>> @@ -317,6 +320,8 @@ static void >>>> ingenic_ipu_plane_atomic_update(struct drm_plane *plane, >>>> JZ_IPU_CTRL_CHIP_EN | JZ_IPU_CTRL_LCDC_SEL); >>>> } >>>> >>>> + ingenic_drm_sync_data(ipu->master, oldstate, newstate); >>>> + >>>> /* New addresses will be committed in vblank handler... */ >>>> ipu->addr_y = drm_fb_cma_get_gem_addr(newstate->fb, newstate, >>>> 0); >>>> if (finfo->num_planes > 1) >>>> @@ -541,7 +546,7 @@ static int >>>> ingenic_ipu_plane_atomic_check(struct drm_plane *plane, >>>> >>>> if (!new_plane_state->crtc || >>>> !crtc_state->mode.hdisplay || !crtc_state->mode.vdisplay) >>>> - return 0; >>>> + goto out_check_damage; >>>> >>>> /* Plane must be fully visible */ >>>> if (new_plane_state->crtc_x < 0 || new_plane_state->crtc_y < 0 >>>> || >>>> @@ -558,7 +563,7 @@ static int >>>> ingenic_ipu_plane_atomic_check(struct drm_plane *plane, >>>> return -EINVAL; >>>> >>>> if (!osd_changed(new_plane_state, old_plane_state)) >>>> - return 0; >>>> + goto out_check_damage; >>>> >>>> crtc_state->mode_changed = true; >>>> >>>> @@ -592,6 +597,9 @@ static int >>>> ingenic_ipu_plane_atomic_check(struct drm_plane *plane, >>>> ipu->denom_w = denom_w; >>>> ipu->denom_h = denom_h; >>>> >>>> +out_check_damage: >>>> + drm_atomic_helper_check_plane_damage(state, new_plane_state); >>>> + >>>> return 0; >>>> } >>>> >>>> @@ -773,6 +781,8 @@ static int ingenic_ipu_bind(struct device >>>> *dev, >>>> struct device *master, void *d) >>>> return err; >>>> } >>>> >>>> + drm_plane_enable_fb_damage_clips(plane); >>>> + >>>> /* >>>> * Sharpness settings range is [0,32] >>>> * 0 : nearest-neighbor >>>> -- >>>> 2.30.1
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