drm/radeon: update comments to clarify VM setup (v2)

The actual set up and assignment of VM page tables
is done on the fly in radeon_gart.c.

v2: update vm size comments

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>

diff --git a/drivers/gpu/drm/radeon/ni.c b/drivers/gpu/drm/radeon/ni.c
index 8bcb554..83dc085 100644 (file)
--- a/drivers/gpu/drm/radeon/ni.c
+++ b/drivers/gpu/drm/radeon/ni.c
@@ -770,6 +770,10 @@ static int cayman_pcie_gart_enable(struct radeon_device *rdev)
        WREG32(0x15DC, 0);
 
        /* empty context1-7 */
+       /* Assign the pt base to something valid for now; the pts used for
+        * the VMs are determined by the application and setup and assigned
+        * on the fly in the vm part of radeon_gart.c
+        */
        for (i = 1; i < 8; i++) {
                WREG32(VM_CONTEXT0_PAGE_TABLE_START_ADDR + (i << 2), 0);
                WREG32(VM_CONTEXT0_PAGE_TABLE_END_ADDR + (i << 2), 0);

diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index 64a4264..bd13ca0 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -1018,6 +1018,10 @@ int radeon_device_init(struct radeon_device *rdev,
                return r;
        /* initialize vm here */
        mutex_init(&rdev->vm_manager.lock);
+       /* Adjust VM size here.
+        * Currently set to 4GB ((1 << 20) 4k pages).
+        * Max GPUVM size for cayman and SI is 40 bits.
+        */
        rdev->vm_manager.max_pfn = 1 << 20;
        INIT_LIST_HEAD(&rdev->vm_manager.lru_vm);
 

diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c
index f79633a..df8dd77 100644 (file)
--- a/drivers/gpu/drm/radeon/si.c
+++ b/drivers/gpu/drm/radeon/si.c
@@ -2407,12 +2407,13 @@ static int si_pcie_gart_enable(struct radeon_device *rdev)
        WREG32(0x15DC, 0);
 
        /* empty context1-15 */
-       /* FIXME start with 4G, once using 2 level pt switch to full
-        * vm size space
-        */
        /* set vm size, must be a multiple of 4 */
        WREG32(VM_CONTEXT1_PAGE_TABLE_START_ADDR, 0);
        WREG32(VM_CONTEXT1_PAGE_TABLE_END_ADDR, rdev->vm_manager.max_pfn);
+       /* Assign the pt base to something valid for now; the pts used for
+        * the VMs are determined by the application and setup and assigned
+        * on the fly in the vm part of radeon_gart.c
+        */
        for (i = 1; i < 16; i++) {
                if (i < 8)
                        WREG32(VM_CONTEXT0_PAGE_TABLE_BASE_ADDR + (i << 2),