target/linux/bcm27xx/patches-6.1/950-0905-drm-v3d-Improve-MMU-support-for-larger-pages.patch

   1 From 12c7ea43b930976f35ce75d11fd3f55438868e13 Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.com>
   3 Date: Fri, 4 Aug 2023 11:26:10 +0100
   4 Subject: [PATCH] drm/v3d: Improve MMU support for larger pages
   5
   6 The built-in MMU driver went most of the way towards supporting larger
   7 kernel pages, but dropped the ball when it comes to calculating indexes
   8 into the page table. Fix it.
   9
  10 Signed-off-by: Phil Elwell <phil@raspberrypi.com>
  11 ---
  12  drivers/gpu/drm/v3d/v3d_mmu.c | 15 ++++++++-------
  13  1 file changed, 8 insertions(+), 7 deletions(-)
  14
  15 --- a/drivers/gpu/drm/v3d/v3d_mmu.c
  16 +++ b/drivers/gpu/drm/v3d/v3d_mmu.c
  17 @@ -22,6 +22,7 @@
  18  #include "v3d_regs.h"
  19
  20  #define V3D_MMU_PAGE_SHIFT 12
  21 +#define V3D_PAGE_FACTOR (PAGE_SIZE >> V3D_MMU_PAGE_SHIFT)
  22
  23  /* Note: All PTEs for the 1MB superpage must be filled with the
  24   * superpage bit set.
  25 @@ -88,7 +89,7 @@ void v3d_mmu_insert_ptes(struct v3d_bo *
  26  {
  27         struct drm_gem_shmem_object *shmem_obj = &bo->base;
  28         struct v3d_dev *v3d = to_v3d_dev(shmem_obj->base.dev);
  29 -       u32 page = bo->node.start;
  30 +       u32 page = bo->node.start * V3D_PAGE_FACTOR;
  31         u32 page_prot = V3D_PTE_WRITEABLE | V3D_PTE_VALID;
  32         struct sg_dma_page_iter dma_iter;
  33
  34 @@ -98,13 +99,13 @@ void v3d_mmu_insert_ptes(struct v3d_bo *
  35                 u32 pte = page_prot | page_address;
  36                 u32 i;
  37
  38 -               BUG_ON(page_address + (PAGE_SIZE >> V3D_MMU_PAGE_SHIFT) >=
  39 +               BUG_ON(page_address + V3D_PAGE_FACTOR >=
  40                        BIT(24));
  41 -               for (i = 0; i < PAGE_SIZE >> V3D_MMU_PAGE_SHIFT; i++)
  42 +               for (i = 0; i < V3D_PAGE_FACTOR; i++)
  43                         v3d->pt[page++] = pte + i;
  44         }
  45
  46 -       WARN_ON_ONCE(page - bo->node.start !=
  47 +       WARN_ON_ONCE(page - (bo->node.start * V3D_PAGE_FACTOR) !=
  48                      shmem_obj->base.size >> V3D_MMU_PAGE_SHIFT);
  49
  50         if (v3d_mmu_flush_all(v3d))
  51 @@ -115,10 +116,10 @@ void v3d_mmu_remove_ptes(struct v3d_bo *
  52  {
  53         struct v3d_dev *v3d = to_v3d_dev(bo->base.base.dev);
  54         u32 npages = bo->base.base.size >> V3D_MMU_PAGE_SHIFT;
  55 -       u32 page;
  56 +       u32 page = bo->node.start * V3D_PAGE_FACTOR;
  57
  58 -       for (page = bo->node.start; page < bo->node.start + npages; page++)
  59 -               v3d->pt[page] = 0;
  60 +       while (npages--)
  61 +               v3d->pt[page++] = 0;
  62
  63         if (v3d_mmu_flush_all(v3d))
  64                 dev_err(v3d->drm.dev, "MMU flush timeout\n");