[PATCH 3/5] drm/msm: use the right pgprot when mapping BOs in the kernel

Jonathan Marek
2021-04-23T19:12:21Z

Use the same logic as the userspace mapping.

This fixes msm_rd with cached BOs.

Signed-off-by: Jonathan Marek <jonathan@marek.ca>
---
drivers/gpu/drm/msm/msm_gem.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 09abda42d764..0f58937be0a9 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -199,6 +199,15 @@ void msm_gem_put_pages(struct drm_gem_object *obj)
/* when we start tracking the pin count, then do something here */
}

+static pgprot_t msm_gem_pgprot(struct msm_gem_object *msm_obj, pgprot_t prot)
+{
+ if (msm_obj->flags & MSM_BO_WC)
+ return pgprot_writecombine(prot);
+ if (msm_obj->flags & MSM_BO_UNCACHED)
+ return pgprot_noncached(prot);
+ return prot;
+}
+
int msm_gem_mmap_obj(struct drm_gem_object *obj,
struct vm_area_struct *vma)
{
@@ -206,13 +215,7 @@ int msm_gem_mmap_obj(struct drm_gem_object *obj,

vma->vm_flags &= ~VM_PFNMAP;
vma->vm_flags |= VM_MIXEDMAP;
-
- if (msm_obj->flags & MSM_BO_WC)
- vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
- else if (msm_obj->flags & MSM_BO_UNCACHED)
- vma->vm_page_prot = pgprot_noncached(vm_get_page_prot(vma->vm_flags));
- else
- vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
+ vma->vm_page_prot = msm_gem_pgprot(msm_obj, vm_get_page_prot(vma->vm_flags));

return 0;
}
@@ -632,7 +635,7 @@ static void *get_vaddr(struct drm_gem_object *obj, unsigned madv)
goto fail;
}
msm_obj->vaddr = vmap(pages, obj->size >> PAGE_SHIFT,
- VM_MAP, pgprot_writecombine(PAGE_KERNEL));
+ VM_MAP, msm_gem_pgprot(msm_obj, PAGE_KERNEL));
if (msm_obj->vaddr == NULL) {
ret = -ENOMEM;
goto fail;
--
2.26.1