[PATCH 6.19 752/844] drm/amdgpu: Use 5-level paging if gmc support 57-bit VA

From: Sasha Levin

Date: Sat Feb 28 2026 - 15:58:36 EST


From: Philip Yang <Philip.Yang@xxxxxxx>

[ Upstream commit 3b948dd0366a0b64c02e4ed1aefdf7825942e803 ]

Regardless if CPU enable 5-level paging, GPU vm use 5-level paging if
gmc init with 57-bit address space support, because

ARM64 4-level paging support 48-bit VA, x86 and GPU 4-level paging
support 47-bit VA, require 5-level paging on GPU to support ARM64.

NPA address space 52-bit mapping on NPA GPU VM require 5-level paging.

Debugger trap get device snapshot expect LDS and Scratch base, limit
above 57-bit, which is set only for 5-level paging.

Signed-off-by: Philip Yang <Philip.Yang@xxxxxxx>
Reviewed-by: Christian König <christian.koenig@xxxxxxx>
Acked-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # 6.19.x
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 17 -----------------
1 file changed, 17 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 4d329454456bc..bd7f83efed187 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2360,26 +2360,9 @@ void amdgpu_vm_adjust_size(struct amdgpu_device *adev, uint32_t min_vm_size,
unsigned max_bits)
{
unsigned int max_size = 1 << (max_bits - 30);
- bool sys_5level_pgtable = false;
unsigned int vm_size;
uint64_t tmp;

-#ifdef CONFIG_X86_64
- /*
- * Refer to function configure_5level_paging() for details.
- */
- sys_5level_pgtable = (native_read_cr4() & X86_CR4_LA57);
-#endif
-
- /*
- * If GPU supports 5-level page table, but system uses 4-level page table,
- * then use 4-level page table on GPU
- */
- if (max_level == 4 && !sys_5level_pgtable) {
- min_vm_size = 256 * 1024;
- max_level = 3;
- }
-
/* adjust vm size first */
if (amdgpu_vm_size != -1) {
vm_size = amdgpu_vm_size;
--
2.51.0