[etnaviv-next v14 4/8] drm/etnaviv: Fix wrong cache property being used for vmap()

From: Sui Jingfeng
Date: Sun May 19 2024 - 12:55:27 EST


In the etnaviv_gem_vmap_impl() function, the driver vmap whatever buffers
with Write-Combine page property. This is unreasonable, as some platforms
are cached coherent. And cached buffers should be mapped with cached page
property.

Fixes: a0a5ab3e99b8 ("drm/etnaviv: call correct function when trying to vmap a DMABUF")
Signed-off-by: Sui Jingfeng <sui.jingfeng@xxxxxxxxx>
---
drivers/gpu/drm/etnaviv/etnaviv_gem.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
index aa95a5e98374..eed98bb9e446 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
@@ -342,6 +342,7 @@ void *etnaviv_gem_vmap(struct drm_gem_object *obj)
static void *etnaviv_gem_vmap_impl(struct etnaviv_gem_object *obj)
{
struct page **pages;
+ pgprot_t prot;

lockdep_assert_held(&obj->lock);

@@ -349,8 +350,19 @@ static void *etnaviv_gem_vmap_impl(struct etnaviv_gem_object *obj)
if (IS_ERR(pages))
return NULL;

- return vmap(pages, obj->base.size >> PAGE_SHIFT,
- VM_MAP, pgprot_writecombine(PAGE_KERNEL));
+ switch (obj->flags) {
+ case ETNA_BO_CACHED:
+ prot = PAGE_KERNEL;
+ break;
+ case ETNA_BO_UNCACHED:
+ prot = pgprot_noncached(PAGE_KERNEL);
+ break;
+ case ETNA_BO_WC:
+ default:
+ prot = pgprot_writecombine(PAGE_KERNEL);
+ }
+
+ return vmap(pages, obj->base.size >> PAGE_SHIFT, VM_MAP, prot);
}

static inline enum dma_data_direction etnaviv_op_to_dma_dir(u32 op)
--
2.34.1