drm/amdgpu: Add helper to turn an existing VM into a compute VM

v2: Removed updating and checking of vm->vm_context
v3: Enable amdgpu_vm_clear_bo in amdgpu_vm_make_compute

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 24474294c92a05fb5e7e9c8908a05c8d1c8a4441..ea39ccf288eda8db1884e2fed4b8b4897696afba 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2461,6 +2461,73 @@ error_free_sched_entity:
        return r;
 }
 
+/**
+ * amdgpu_vm_make_compute - Turn a GFX VM into a compute VM
+ *
+ * This only works on GFX VMs that don't have any BOs added and no
+ * page tables allocated yet.
+ *
+ * Changes the following VM parameters:
+ * - use_cpu_for_update
+ * - pte_supports_ats
+ * - pasid (old PASID is released, because compute manages its own PASIDs)
+ *
+ * Reinitializes the page directory to reflect the changed ATS
+ * setting. May leave behind an unused shadow BO for the page
+ * directory when switching from SDMA updates to CPU updates.
+ *
+ * Returns 0 for success, -errno for errors.
+ */
+int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm)
+{
+       bool pte_support_ats = (adev->asic_type == CHIP_RAVEN);
+       int r;
+
+       r = amdgpu_bo_reserve(vm->root.base.bo, true);
+       if (r)
+               return r;
+
+       /* Sanity checks */
+       if (!RB_EMPTY_ROOT(&vm->va.rb_root) || vm->root.entries) {
+               r = -EINVAL;
+               goto error;
+       }
+
+       /* Check if PD needs to be reinitialized and do it before
+        * changing any other state, in case it fails.
+        */
+       if (pte_support_ats != vm->pte_support_ats) {
+               r = amdgpu_vm_clear_bo(adev, vm, vm->root.base.bo,
+                              adev->vm_manager.root_level,
+                              pte_support_ats);
+               if (r)
+                       goto error;
+       }
+
+       /* Update VM state */
+       vm->use_cpu_for_update = !!(adev->vm_manager.vm_update_mode &
+                                   AMDGPU_VM_USE_CPU_FOR_COMPUTE);
+       vm->pte_support_ats = pte_support_ats;
+       DRM_DEBUG_DRIVER("VM update mode is %s\n",
+                        vm->use_cpu_for_update ? "CPU" : "SDMA");
+       WARN_ONCE((vm->use_cpu_for_update & !amdgpu_vm_is_large_bar(adev)),
+                 "CPU update of VM recommended only for large BAR system\n");
+
+       if (vm->pasid) {
+               unsigned long flags;
+
+               spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
+               idr_remove(&adev->vm_manager.pasid_idr, vm->pasid);
+               spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
+
+               vm->pasid = 0;
+       }
+
+error:
+       amdgpu_bo_unreserve(vm->root.base.bo);
+       return r;
+}
+
 /**
  * amdgpu_vm_free_levels - free PD/PT levels
  *

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
index 4dfdefb7de1fefd96d486f303a65a1a6756310c8..30f080364c97b5109785419e98151262cf687848 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
@@ -260,6 +260,7 @@ void amdgpu_vm_manager_init(struct amdgpu_device *adev);
 void amdgpu_vm_manager_fini(struct amdgpu_device *adev);
 int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
                   int vm_context, unsigned int pasid);
+int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm);
 void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm);
 bool amdgpu_vm_pasid_fault_credit(struct amdgpu_device *adev,
                                  unsigned int pasid);