drm/amdgpu: Add PASID management

Allows assigning a PASID to a VM for identifying VMs involved in page
faults. The global PASID manager is also exported in the KFD
interface so that AMDGPU and KFD can share the PASID space.

PASIDs of different sizes can be requested. On APUs, the PASID size
is deterined by the capabilities of the IOMMU. So KFD must be able
to allocate PASIDs in a smaller range.

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
index 48c58ae4bb3a..7873dfa8c0f9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
@@ -25,6 +25,7 @@
 #define __AMDGPU_VM_H__
 
 #include <linux/rbtree.h>
+#include <linux/idr.h>
 
 #include "gpu_scheduler.h"
 #include "amdgpu_sync.h"
@@ -148,8 +149,9 @@ struct amdgpu_vm {
         /* Scheduler entity for page table updates */
         struct amd_sched_entity entity;
 
-        /* client id */
+        /* client id and PASID (TODO: replace client_id with PASID) */
         u64                     client_id;
+        unsigned int            pasid;
         /* dedicated to vm */
         struct amdgpu_vm_id     *reserved_vmid[AMDGPU_MAX_VMHUBS];
 
@@ -220,12 +222,20 @@ struct amdgpu_vm_manager {
          * BIT1[= 0] Compute updated by SDMA [= 1] by CPU
          */
         int                                     vm_update_mode;
+
+        /* PASID to VM mapping, will be used in interrupt context to
+         * look up VM of a page fault
+         */
+        struct idr                              pasid_idr;
+        spinlock_t                              pasid_lock;
 };
 
+int amdgpu_vm_alloc_pasid(unsigned int bits);
+void amdgpu_vm_free_pasid(unsigned int pasid);
 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);
+                   int vm_context, unsigned int pasid);
 void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm);
 void amdgpu_vm_get_pd_bo(struct amdgpu_vm *vm,
                          struct list_head *validated,