From: Alex Deucher alexander.deucher@amd.com
Document the VM functions in radeon_gart.c
v2: adjust per Christian's suggestions v3: adjust to Christians's latest changes
Signed-off-by: Alex Deucher alexander.deucher@amd.com Reviewed-by: Christian König christian.koenig@amd.com --- drivers/gpu/drm/radeon/radeon_gart.c | 142 ++++++++++++++++++++++++++++++++++ 1 files changed, 142 insertions(+), 0 deletions(-)
diff --git a/drivers/gpu/drm/radeon/radeon_gart.c b/drivers/gpu/drm/radeon/radeon_gart.c index 12135ec..9727ea1 100644 --- a/drivers/gpu/drm/radeon/radeon_gart.c +++ b/drivers/gpu/drm/radeon/radeon_gart.c @@ -397,11 +397,39 @@ void radeon_gart_fini(struct radeon_device *rdev) }
/* + * GPUVM + * GPUVM is similar to the legacy gart on older asics, however + * rather than there being a single global gart table + * for the entire GPU, there are multiple VM page tables active + * at any given time. The VM page tables can contain a mix + * vram pages and system memory pages and system memory pages + * can be mapped as snooped (cached system pages) or unsnooped + * (uncached system pages). + * Each VM has an ID associated with it and there is a page table + * associated with each VMID. When execting a command buffer, + * the kernel tells the the ring what VMID to use for that command + * buffer. VMIDs are allocated dynamically as commands are submitted. + * The userspace drivers maintain their own address space and the kernel + * sets up their pages tables accordingly when they submit their + * command buffers and a VMID is assigned. + * Cayman/Trinity support up to 8 active VMs at any given time; + * SI supports 16. + */ + +/* * vm helpers * * TODO bind a default page at vm initialization for default address */
+/** + * radeon_vm_manager_init - init the vm manager + * + * @rdev: radeon_device pointer + * + * Init the vm manager (cayman+). + * Returns 0 for success, error for failure. + */ int radeon_vm_manager_init(struct radeon_device *rdev) { struct radeon_vm *vm; @@ -456,6 +484,16 @@ int radeon_vm_manager_init(struct radeon_device *rdev) }
/* global mutex must be lock */ +/** + * radeon_vm_unbind_locked - unbind a specific vm + * + * @rdev: radeon_device pointer + * @vm: vm to unbind + * + * Unbind the requested vm (cayman+). + * Wait for use of the VM to finish, then unbind the page table, + * and free the page table memory. + */ static void radeon_vm_unbind_locked(struct radeon_device *rdev, struct radeon_vm *vm) { @@ -495,6 +533,13 @@ static void radeon_vm_unbind_locked(struct radeon_device *rdev, } }
+/** + * radeon_vm_manager_fini - tear down the vm manager + * + * @rdev: radeon_device pointer + * + * Tear down the VM manager (cayman+). + */ void radeon_vm_manager_fini(struct radeon_device *rdev) { struct radeon_vm *vm, *tmp; @@ -516,6 +561,14 @@ void radeon_vm_manager_fini(struct radeon_device *rdev) }
/* global mutex must be locked */ +/** + * radeon_vm_unbind - locked version of unbind + * + * @rdev: radeon_device pointer + * @vm: vm to unbind + * + * Locked version that wraps radeon_vm_unbind_locked (cayman+). + */ void radeon_vm_unbind(struct radeon_device *rdev, struct radeon_vm *vm) { mutex_lock(&vm->mutex); @@ -524,6 +577,18 @@ void radeon_vm_unbind(struct radeon_device *rdev, struct radeon_vm *vm) }
/* global and local mutex must be locked */ +/** + * radeon_vm_bind - bind a page table to a VMID + * + * @rdev: radeon_device pointer + * @vm: vm to bind + * + * Bind the requested vm (cayman+). + * Suballocate memory for the page table, allocate a VMID + * and bind the page table to it, and finally start to populate + * the page table. + * Returns 0 for success, error for failure. + */ int radeon_vm_bind(struct radeon_device *rdev, struct radeon_vm *vm) { struct radeon_vm *vm_evict; @@ -586,6 +651,20 @@ retry_id: }
/* object have to be reserved */ +/** + * radeon_vm_bo_add - add a bo to a specific vm + * + * @rdev: radeon_device pointer + * @vm: requested vm + * @bo: radeon buffer object + * @offset: requested offset of the buffer in the VM address space + * @flags: attributes of pages (read/write/valid/etc.) + * + * Add @bo into the requested vm (cayman+). + * Add @bo to the list of bos associated with the vm and validate + * the offset requested within the vm address space. + * Returns 0 for success, error for failure. + */ int radeon_vm_bo_add(struct radeon_device *rdev, struct radeon_vm *vm, struct radeon_bo *bo, @@ -663,6 +742,17 @@ int radeon_vm_bo_add(struct radeon_device *rdev, return 0; }
+/** + * radeon_vm_get_addr - get the physical address of the page + * + * @rdev: radeon_device pointer + * @mem: ttm mem + * @pfn: pfn + * + * Look up the physical address of the page that the pte resolves + * to (cayman+). + * Returns the physical address of the page. + */ static u64 radeon_vm_get_addr(struct radeon_device *rdev, struct ttm_mem_reg *mem, unsigned pfn) @@ -692,6 +782,17 @@ static u64 radeon_vm_get_addr(struct radeon_device *rdev, }
/* object have to be reserved & global and local mutex must be locked */ +/** + * radeon_vm_bo_update_pte - map a bo into the vm page table + * + * @rdev: radeon_device pointer + * @vm: requested vm + * @bo: radeon buffer object + * @mem: ttm mem + * + * Fill in the page table entries for @bo (cayman+). + * Returns 0 for success, -EINVAL for failure. + */ int radeon_vm_bo_update_pte(struct radeon_device *rdev, struct radeon_vm *vm, struct radeon_bo *bo, @@ -740,6 +841,18 @@ int radeon_vm_bo_update_pte(struct radeon_device *rdev, }
/* object have to be reserved */ +/** + * radeon_vm_bo_rmv - remove a bo to a specific vm + * + * @rdev: radeon_device pointer + * @vm: requested vm + * @bo: radeon buffer object + * + * Remove @bo from the requested vm (cayman+). + * Remove @bo from the list of bos associated with the vm and + * remove the ptes for @bo in the page table. + * Returns 0 for success. + */ int radeon_vm_bo_rmv(struct radeon_device *rdev, struct radeon_vm *vm, struct radeon_bo *bo) @@ -762,6 +875,15 @@ int radeon_vm_bo_rmv(struct radeon_device *rdev, return 0; }
+/** + * radeon_vm_bo_invalidate - mark the bo as invalid + * + * @rdev: radeon_device pointer + * @vm: requested vm + * @bo: radeon buffer object + * + * Mark @bo as invalid (cayman+). + */ void radeon_vm_bo_invalidate(struct radeon_device *rdev, struct radeon_bo *bo) { @@ -773,6 +895,17 @@ void radeon_vm_bo_invalidate(struct radeon_device *rdev, } }
+/** + * radeon_vm_init - initialize a vm instance + * + * @rdev: radeon_device pointer + * @vm: requested vm + * + * Init @vm (cayman+). + * Map the IB pool and any other shared objects into the VM + * by default as it's used by all VMs. + * Returns 0 for success, error for failure. + */ int radeon_vm_init(struct radeon_device *rdev, struct radeon_vm *vm) { int r; @@ -791,6 +924,15 @@ int radeon_vm_init(struct radeon_device *rdev, struct radeon_vm *vm) return r; }
+/** + * radeon_vm_init - tear down a vm instance + * + * @rdev: radeon_device pointer + * @vm: requested vm + * + * Tear down @vm (cayman+). + * Unbind the VM and remove all bos from the vm bo list + */ void radeon_vm_fini(struct radeon_device *rdev, struct radeon_vm *vm) { struct radeon_bo_va *bo_va, *tmp;