target/linux/brcm2708/patches-4.4/0588-drm-vc4-Verify-at-boot-that-CMA-doesn-t-cross-a-256M.patch

   1 From bf4b7e8817115f839241e55add244cf60225e436 Mon Sep 17 00:00:00 2001
   2 From: Eric Anholt <eric@anholt.net>
   3 Date: Mon, 12 Oct 2015 08:58:08 -0700
   4 Subject: [PATCH] drm/vc4: Verify at boot that CMA doesn't cross a 256MB
   5  boundary.
   6
   7 I've seen lots of users cranking CMA up higher, so throw an error if
   8 they do.
   9
  10 Signed-off-by: Eric Anholt <eric@anholt.net>
  11 ---
  12  drivers/base/dma-contiguous.c |  1 +
  13  drivers/gpu/drm/vc4/vc4_v3d.c | 18 ++++++++++++++++++
  14  mm/cma.c                      |  2 ++
  15  3 files changed, 21 insertions(+)
  16
  17 diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
  18 index e167a1e1..60f5c25 100644
  19 --- a/drivers/base/dma-contiguous.c
  20 +++ b/drivers/base/dma-contiguous.c
  21 @@ -35,6 +35,7 @@
  22  #endif
  23
  24  struct cma *dma_contiguous_default_area;
  25 +EXPORT_SYMBOL(dma_contiguous_default_area);
  26
  27  /*
  28   * Default global CMA area size can be defined in kernel's .config.
  29 diff --git a/drivers/gpu/drm/vc4/vc4_v3d.c b/drivers/gpu/drm/vc4/vc4_v3d.c
  30 index 7cc346a..1d9e5a6 100644
  31 --- a/drivers/gpu/drm/vc4/vc4_v3d.c
  32 +++ b/drivers/gpu/drm/vc4/vc4_v3d.c
  33 @@ -16,7 +16,10 @@
  34   * this program.  If not, see <http://www.gnu.org/licenses/>.
  35   */
  36
  37 +#include "linux/init.h"
  38 +#include "linux/cma.h"
  39  #include "linux/component.h"
  40 +#include "linux/dma-contiguous.h"
  41  #include "linux/pm_runtime.h"
  42  #include "vc4_drv.h"
  43  #include "vc4_regs.h"
  44 @@ -185,8 +188,23 @@ static int vc4_v3d_bind(struct device *dev, struct device *master, void *data)
  45         struct drm_device *drm = dev_get_drvdata(master);
  46         struct vc4_dev *vc4 = to_vc4_dev(drm);
  47         struct vc4_v3d *v3d = NULL;
  48 +       struct cma *cma;
  49         int ret;
  50
  51 +       cma = dev_get_cma_area(dev);
  52 +       if (!cma)
  53 +               return -EINVAL;
  54 +
  55 +       if ((cma_get_base(cma) & 0xf0000000) !=
  56 +           ((cma_get_base(cma) + cma_get_size(cma) - 1) & 0xf0000000)) {
  57 +               DRM_ERROR("V3D requires that the CMA area (0x%08lx - 0x%08lx) "
  58 +                         "not span a 256MB boundary, or memory corruption "
  59 +                         "would happen.\n",
  60 +                         (long)cma_get_base(cma),
  61 +                         cma_get_base(cma) + cma_get_size(cma));
  62 +               return -EINVAL;
  63 +       }
  64 +
  65         v3d = devm_kzalloc(&pdev->dev, sizeof(*v3d), GFP_KERNEL);
  66         if (!v3d)
  67                 return -ENOMEM;
  68 diff --git a/mm/cma.c b/mm/cma.c
  69 index bd0e141..efac29b 100644
  70 --- a/mm/cma.c
  71 +++ b/mm/cma.c
  72 @@ -47,11 +47,13 @@ phys_addr_t cma_get_base(const struct cma *cma)
  73  {
  74         return PFN_PHYS(cma->base_pfn);
  75  }
  76 +EXPORT_SYMBOL(cma_get_base);
  77
  78  unsigned long cma_get_size(const struct cma *cma)
  79  {
  80         return cma->count << PAGE_SHIFT;
  81  }
  82 +EXPORT_SYMBOL(cma_get_size);
  83
  84  static unsigned long cma_bitmap_aligned_mask(const struct cma *cma,
  85                                              int align_order)
  86 --
  87 2.1.4
  88