struct dc has grown large over time (most of it the two inlined
dc_scratch_space copies) and now sits close to the page allocator's 4 MiB
contiguous allocation limit. Its actual size is not fixed by the source
alone, it also depends on the compiler and the .config, so it can easily
cross 4 MiB, e.g. with a newer GCC or a config change.
dc_create() allocates it with kzalloc(). Once struct dc exceeds 4 MiB the
request is rounded up to order 11 (8 MiB), which is above MAX_PAGE_ORDER,
so the page allocator warns and returns NULL. dc_create() then fails, DM
init fails and amdgpu probe aborts with -EINVAL:
WARNING: mm/page_alloc.c:5197 at __alloc_frozen_pages_noprof+0x2f9/0x380
dc_create+0x38/0x660 [amdgpu]
amdgpu_dm_init+0x2d9/0x510 [amdgpu]
dm_hw_init+0x1b/0x90 [amdgpu]
amdgpu_device_init.cold+0x150d/0x1e13 [amdgpu]
amdgpu_driver_load_kms+0x19/0x80 [amdgpu]
amdgpu_pci_probe+0x1e2/0x4c0 [amdgpu]
dc_create() then returns NULL and DM init fails, which aborts the whole
GPU init and makes amdgpu probe fail with -EINVAL ("hw_init of IP block
<dm> failed -22"), leaving the display unusable. The subsequent
amdgpu_irq_put() warnings during teardown are just fallout of unwinding
a half-initialized device.
struct dc is a software-only bookkeeping structure that is never handed
to hardware DMA and is only ever kept as an opaque pointer, so it does
not require physically contiguous memory. Allocate it with kvzalloc()
(and free it with kvfree()) so that the allocator can fall back to
vmalloc() when a contiguous allocation of that size is not available,
which also avoids the MAX_PAGE_ORDER warning entirely.
v2:
- Rebase to amd-staging-drm-next.
Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/5406
Cc: [email protected]
Reviewed-by: Mario Limonciello (AMD) <[email protected]>
Signed-off-by: Honglei Huang <[email protected]>
---
drivers/gpu/drm/amd/display/dc/core/dc.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c
b/drivers/gpu/drm/amd/display/dc/core/dc.c
index ae776519e6e..99d08bfad53 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -1509,7 +1509,7 @@ static void disable_vbios_mode_if_required(
struct dc *dc_create(const struct dc_init_data *init_params)
{
- struct dc *dc = kzalloc(sizeof(*dc), GFP_KERNEL);
+ struct dc *dc = kvzalloc(sizeof(*dc), GFP_KERNEL);
unsigned int full_pipe_count;
if (!dc)
@@ -1557,7 +1557,7 @@ struct dc *dc_create(const struct dc_init_data
*init_params)
destruct_dc:
dc_destruct(dc);
- kfree(dc);
+ kvfree(dc);
return NULL;
}
@@ -1606,7 +1606,7 @@ void dc_deinit_callbacks(struct dc *dc)
void dc_destroy(struct dc **dc)
{
dc_destruct(*dc);
- kfree(*dc);
+ kvfree(*dc);
*dc = NULL;
}
--
2.34.1
