[PATCH 1/2] drm/amdgpu: increase the reserved VM size to 2MB

[Chauhan, Madhav]

[AMD Public Use]

-----Original Message-----
From: Christian König <ckoenig.leichtzumerken at gmail.com> 
Sent: Tuesday, October 13, 2020 10:38 PM
To: amd-gfx at lists.freedesktop.org
Cc: Chauhan, Madhav <Madhav.Chauhan at amd.com>; Pan, Xinhui <Xinhui.Pan at amd.com>
Subject: [PATCH 1/2] drm/amdgpu: increase the reserved VM size to 2MB

Ideally this should be a multiple of the VM block size.
2MB should at least fit for Vega/Navi.

Signed-off-by: Christian König <christian.koenig at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
index 7c46937c1c0e..81ccd0a0c3db 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
@@ -112,8 +112,8 @@ struct amdgpu_bo_list_entry;
 #define AMDGPU_MMHUB_0				1
 #define AMDGPU_MMHUB_1				2
 
-/* hardcode that limit for now */
-#define AMDGPU_VA_RESERVED_SIZE			(1ULL << 20)
+/* Reserve 2MB at top/bottom of address space for kernel use */
+#define AMDGPU_VA_RESERVED_SIZE			(2ULL << 20)

Looks fine to me: Reviewed-by: Madhav Chauhan <madhav.chauhan at amd.com>
Clarification on comment:
We check va_address < AMDGPU_VA_RESERVED_SIZE for invalid reservations, shouldn’t this be "bottom"instead of "top/bottom" of address space??

Regards,
Madhav
 
 /* max vmids dedicated for process */
 #define AMDGPU_VM_MAX_RESERVED_VMID	1
-- 
2.17.1