On Wed, Oct 28, 2020 at 3:36 PM Patrik Jakobsson
<patrik.r.jakobsson@xxxxxxxxx> wrote:
>
> GTT roll support was used to accelerate fb panning on some machines.
> Unfortunately this never worked properly with multiple monitors and
> caused issues on others where the framebuffer wouldn't fit in stolen
> memory. Let's remove it!
Acked-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
btw I tried to figure out whether the accel code is of any use too,
and we don't set FBINFO_HWACCEL_COPYAREA, despite that we have an
accelerated copyarea. So I think we could delete all that code too,
since essentially unused. And aside of fbcon no one is using these
acceleration functions anyway.
-Daniel
>
> Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@xxxxxxxxx>
> ---
> drivers/gpu/drm/gma500/framebuffer.c | 96 ++++------------------------
> drivers/gpu/drm/gma500/gtt.c | 52 +--------------
> drivers/gpu/drm/gma500/gtt.h | 3 -
> 3 files changed, 14 insertions(+), 137 deletions(-)
>
> diff --git a/drivers/gpu/drm/gma500/framebuffer.c b/drivers/gpu/drm/gma500/framebuffer.c
> index 5ede24fb44ae..2d64c58607f5 100644
> --- a/drivers/gpu/drm/gma500/framebuffer.c
> +++ b/drivers/gpu/drm/gma500/framebuffer.c
> @@ -76,27 +76,6 @@ static int psbfb_setcolreg(unsigned regno, unsigned red, unsigned green,
> return 0;
> }
>
> -static int psbfb_pan(struct fb_var_screeninfo *var, struct fb_info *info)
> -{
> - struct drm_fb_helper *fb_helper = info->par;
> - struct drm_framebuffer *fb = fb_helper->fb;
> - struct drm_device *dev = fb->dev;
> - struct gtt_range *gtt = to_gtt_range(fb->obj[0]);
> -
> - /*
> - * We have to poke our nose in here. The core fb code assumes
> - * panning is part of the hardware that can be invoked before
> - * the actual fb is mapped. In our case that isn't quite true.
> - */
> - if (gtt->npage) {
> - /* GTT roll shifts in 4K pages, we need to shift the right
> - number of pages */
> - int pages = info->fix.line_length >> 12;
> - psb_gtt_roll(dev, gtt, var->yoffset * pages);
> - }
> - return 0;
> -}
> -
> static vm_fault_t psbfb_vm_fault(struct vm_fault *vmf)
> {
> struct vm_area_struct *vma = vmf->vma;
> @@ -176,17 +155,6 @@ static const struct fb_ops psbfb_ops = {
> .fb_sync = psbfb_sync,
> };
>
> -static const struct fb_ops psbfb_roll_ops = {
> - .owner = THIS_MODULE,
> - DRM_FB_HELPER_DEFAULT_OPS,
> - .fb_setcolreg = psbfb_setcolreg,
> - .fb_fillrect = drm_fb_helper_cfb_fillrect,
> - .fb_copyarea = drm_fb_helper_cfb_copyarea,
> - .fb_imageblit = drm_fb_helper_cfb_imageblit,
> - .fb_pan_display = psbfb_pan,
> - .fb_mmap = psbfb_mmap,
> -};
> -
> static const struct fb_ops psbfb_unaccel_ops = {
> .owner = THIS_MODULE,
> DRM_FB_HELPER_DEFAULT_OPS,
> @@ -312,8 +280,6 @@ static int psbfb_create(struct drm_fb_helper *fb_helper,
> int ret;
> struct gtt_range *backing;
> u32 bpp, depth;
> - int gtt_roll = 0;
> - int pitch_lines = 0;
>
> mode_cmd.width = sizes->surface_width;
> mode_cmd.height = sizes->surface_height;
> @@ -324,50 +290,15 @@ static int psbfb_create(struct drm_fb_helper *fb_helper,
> if (bpp == 24)
> bpp = 32;
>
> - do {
> - /*
> - * Acceleration via the GTT requires pitch to be
> - * power of two aligned. Preferably page but less
> - * is ok with some fonts
> - */
> - mode_cmd.pitches[0] = ALIGN(mode_cmd.width * ((bpp + 7) / 8), 4096 >> pitch_lines);
> -
> - size = mode_cmd.pitches[0] * mode_cmd.height;
> - size = ALIGN(size, PAGE_SIZE);
> -
> - /* Allocate the fb in the GTT with stolen page backing */
> - backing = psbfb_alloc(dev, size);
> -
> - if (pitch_lines)
> - pitch_lines *= 2;
> - else
> - pitch_lines = 1;
> - gtt_roll++;
> - } while (backing == NULL && pitch_lines <= 16);
> -
> - /* The final pitch we accepted if we succeeded */
> - pitch_lines /= 2;
> -
> - if (backing == NULL) {
> - /*
> - * We couldn't get the space we wanted, fall back to the
> - * display engine requirement instead. The HW requires
> - * the pitch to be 64 byte aligned
> - */
> -
> - gtt_roll = 0; /* Don't use GTT accelerated scrolling */
> - pitch_lines = 64;
> -
> - mode_cmd.pitches[0] = ALIGN(mode_cmd.width * ((bpp + 7) / 8), 64);
> -
> - size = mode_cmd.pitches[0] * mode_cmd.height;
> - size = ALIGN(size, PAGE_SIZE);
> -
> - /* Allocate the framebuffer in the GTT with stolen page backing */
> - backing = psbfb_alloc(dev, size);
> - if (backing == NULL)
> - return -ENOMEM;
> - }
> + mode_cmd.pitches[0] = ALIGN(mode_cmd.width * DIV_ROUND_UP(bpp, 8), 64);
> +
> + size = mode_cmd.pitches[0] * mode_cmd.height;
> + size = ALIGN(size, PAGE_SIZE);
> +
> + /* Allocate the framebuffer in the GTT with stolen page backing */
> + backing = psbfb_alloc(dev, size);
> + if (backing == NULL)
> + return -ENOMEM;
>
> memset(dev_priv->vram_addr + backing->offset, 0, size);
>
> @@ -387,17 +318,14 @@ static int psbfb_create(struct drm_fb_helper *fb_helper,
>
> fb_helper->fb = fb;
>
> - if (dev_priv->ops->accel_2d && pitch_lines > 8) /* 2D engine */
> + if (dev_priv->ops->accel_2d) /* 2D engine */
> info->fbops = &psbfb_ops;
> - else if (gtt_roll) { /* GTT rolling seems best */
> - info->fbops = &psbfb_roll_ops;
> - info->flags |= FBINFO_HWACCEL_YPAN;
> - } else /* Software */
> + else /* Software */
> info->fbops = &psbfb_unaccel_ops;
>
> info->fix.smem_start = dev->mode_config.fb_base;
> info->fix.smem_len = size;
> - info->fix.ywrapstep = gtt_roll;
> + info->fix.ywrapstep = 0;
> info->fix.ypanstep = 0;
>
> /* Accessed stolen memory directly */
> diff --git a/drivers/gpu/drm/gma500/gtt.c b/drivers/gpu/drm/gma500/gtt.c
> index 9278bcfad1bf..d246b1f70366 100644
> --- a/drivers/gpu/drm/gma500/gtt.c
> +++ b/drivers/gpu/drm/gma500/gtt.c
> @@ -96,16 +96,12 @@ static int psb_gtt_insert(struct drm_device *dev, struct gtt_range *r,
> }
>
> /* Write our page entries into the GTT itself */
> - for (i = r->roll; i < r->npage; i++) {
> - pte = psb_gtt_mask_pte(page_to_pfn(r->pages[i]),
> - PSB_MMU_CACHED_MEMORY);
> - iowrite32(pte, gtt_slot++);
> - }
> - for (i = 0; i < r->roll; i++) {
> + for (i = 0; i < r->npage; i++) {
> pte = psb_gtt_mask_pte(page_to_pfn(r->pages[i]),
> PSB_MMU_CACHED_MEMORY);
> iowrite32(pte, gtt_slot++);
> }
> +
> /* Make sure all the entries are set before we return */
> ioread32(gtt_slot - 1);
>
> @@ -140,49 +136,6 @@ static void psb_gtt_remove(struct drm_device *dev, struct gtt_range *r)
> set_pages_array_wb(r->pages, r->npage);
> }
>
> -/**
> - * psb_gtt_roll - set scrolling position
> - * @dev: our DRM device
> - * @r: the gtt mapping we are using
> - * @roll: roll offset
> - *
> - * Roll an existing pinned mapping by moving the pages through the GTT.
> - * This allows us to implement hardware scrolling on the consoles without
> - * a 2D engine
> - */
> -void psb_gtt_roll(struct drm_device *dev, struct gtt_range *r, int roll)
> -{
> - u32 __iomem *gtt_slot;
> - u32 pte;
> - int i;
> -
> - if (roll >= r->npage) {
> - WARN_ON(1);
> - return;
> - }
> -
> - r->roll = roll;
> -
> - /* Not currently in the GTT - no worry we will write the mapping at
> - the right position when it gets pinned */
> - if (!r->stolen && !r->in_gart)
> - return;
> -
> - gtt_slot = psb_gtt_entry(dev, r);
> -
> - for (i = r->roll; i < r->npage; i++) {
> - pte = psb_gtt_mask_pte(page_to_pfn(r->pages[i]),
> - PSB_MMU_CACHED_MEMORY);
> - iowrite32(pte, gtt_slot++);
> - }
> - for (i = 0; i < r->roll; i++) {
> - pte = psb_gtt_mask_pte(page_to_pfn(r->pages[i]),
> - PSB_MMU_CACHED_MEMORY);
> - iowrite32(pte, gtt_slot++);
> - }
> - ioread32(gtt_slot - 1);
> -}
> -
> /**
> * psb_gtt_attach_pages - attach and pin GEM pages
> * @gt: the gtt range
> @@ -346,7 +299,6 @@ struct gtt_range *psb_gtt_alloc_range(struct drm_device *dev, int len,
> gt->resource.name = name;
> gt->stolen = backed;
> gt->in_gart = backed;
> - gt->roll = 0;
> /* Ensure this is set for non GEM objects */
> gt->gem.dev = dev;
> ret = allocate_resource(dev_priv->gtt_mem, >->resource,
> diff --git a/drivers/gpu/drm/gma500/gtt.h b/drivers/gpu/drm/gma500/gtt.h
> index 3cf190295ad3..2bf165849ebe 100644
> --- a/drivers/gpu/drm/gma500/gtt.h
> +++ b/drivers/gpu/drm/gma500/gtt.h
> @@ -37,7 +37,6 @@ struct gtt_range {
> bool mmapping; /* Is mmappable */
> struct page **pages; /* Backing pages if present */
> int npage; /* Number of backing pages */
> - int roll; /* Roll applied to the GTT entries */
> };
>
> #define to_gtt_range(x) container_of(x, struct gtt_range, gem)
> @@ -49,7 +48,5 @@ extern void psb_gtt_kref_put(struct gtt_range *gt);
> extern void psb_gtt_free_range(struct drm_device *dev, struct gtt_range *gt);
> extern int psb_gtt_pin(struct gtt_range *gt);
> extern void psb_gtt_unpin(struct gtt_range *gt);
> -extern void psb_gtt_roll(struct drm_device *dev,
> - struct gtt_range *gt, int roll);
> extern int psb_gtt_restore(struct drm_device *dev);
> #endif
> --
> 2.28.0
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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