6 files changed, 97 insertions, 4 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c
index b9dbbf9cb8b0..dc7e25cce741 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c
@@ -169,6 +169,8 @@ static const struct kfd2kgd_calls kfd2kgd = {
         .get_vmem_size = get_vmem_size,
         .get_gpu_clock_counter = get_gpu_clock_counter,
         .get_max_engine_clock_in_mhz = get_max_engine_clock_in_mhz,
+        .alloc_pasid = amdgpu_vm_alloc_pasid,
+        .free_pasid = amdgpu_vm_free_pasid,
         .program_sh_mem_settings = kgd_program_sh_mem_settings,
         .set_pasid_vmid_mapping = kgd_set_pasid_vmid_mapping,
         .init_pipeline = kgd_init_pipeline,
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c
index 309f2419c6d8..c678c69936a0 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c
@@ -128,6 +128,8 @@ static const struct kfd2kgd_calls kfd2kgd = {
         .get_vmem_size = get_vmem_size,
         .get_gpu_clock_counter = get_gpu_clock_counter,
         .get_max_engine_clock_in_mhz = get_max_engine_clock_in_mhz,
+        .alloc_pasid = amdgpu_vm_alloc_pasid,
+        .free_pasid = amdgpu_vm_free_pasid,
         .program_sh_mem_settings = kgd_program_sh_mem_settings,
         .set_pasid_vmid_mapping = kgd_set_pasid_vmid_mapping,
         .init_pipeline = kgd_init_pipeline,
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
index e16229000a98..79d9ab43d42c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
@@ -825,7 +825,7 @@ int amdgpu_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv)
         }
 
         r = amdgpu_vm_init(adev, &fpriv->vm,
-                           AMDGPU_VM_CONTEXT_GFX);
+                           AMDGPU_VM_CONTEXT_GFX, 0);
         if (r) {
                 kfree(fpriv);
                 goto out_suspend;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 2196bca7331c..9b795915cab1 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -27,12 +27,59 @@
  */
 #include <linux/dma-fence-array.h>
 #include <linux/interval_tree_generic.h>
+#include <linux/idr.h>
 #include <drm/drmP.h>
 #include <drm/amdgpu_drm.h>
 #include "amdgpu.h"
 #include "amdgpu_trace.h"
 
 /*
+ * PASID manager
+ *
+ * PASIDs are global address space identifiers that can be shared
+ * between the GPU, an IOMMU and the driver. VMs on different devices
+ * may use the same PASID if they share the same address
+ * space. Therefore PASIDs are allocated using a global IDA. VMs are
+ * looked up from the PASID per amdgpu_device.
+ */
+static DEFINE_IDA(amdgpu_vm_pasid_ida);
+
+/**
+ * amdgpu_vm_alloc_pasid - Allocate a PASID
+ * @bits: Maximum width of the PASID in bits, must be at least 1
+ *
+ * Allocates a PASID of the given width while keeping smaller PASIDs
+ * available if possible.
+ *
+ * Returns a positive integer on success. Returns %-EINVAL if bits==0.
+ * Returns %-ENOSPC if no PASID was available. Returns %-ENOMEM on
+ * memory allocation failure.
+ */
+int amdgpu_vm_alloc_pasid(unsigned int bits)
+{
+        int pasid = -EINVAL;
+
+        for (bits = min(bits, 31U); bits > 0; bits--) {
+                pasid = ida_simple_get(&amdgpu_vm_pasid_ida,
+                                       1U << (bits - 1), 1U << bits,
+                                       GFP_KERNEL);
+                if (pasid != -ENOSPC)
+                        break;
+        }
+
+        return pasid;
+}
+
+/**
+ * amdgpu_vm_free_pasid - Free a PASID
+ * @pasid: PASID to free
+ */
+void amdgpu_vm_free_pasid(unsigned int pasid)
+{
+        ida_simple_remove(&amdgpu_vm_pasid_ida, pasid);
+}
+
+/*
  * GPUVM
  * GPUVM is similar to the legacy gart on older asics, however
  * rather than there being a single global gart table
@@ -2539,7 +2586,7 @@ void amdgpu_vm_adjust_size(struct amdgpu_device *adev, uint64_t vm_size, uint32_
  * Init @vm fields.
  */
 int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
-                   int vm_context)
+                   int vm_context, unsigned int pasid)
 {
         const unsigned align = min(AMDGPU_VM_PTB_ALIGN_SIZE,
                 AMDGPU_VM_PTE_COUNT(adev) * 8);
@@ -2620,6 +2667,19 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
                         goto error_free_root;
         }
 
+        if (pasid) {
+                unsigned long flags;
+
+                spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
+                r = idr_alloc(&adev->vm_manager.pasid_idr, vm, pasid, pasid + 1,
+                              GFP_ATOMIC);
+                spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
+                if (r < 0)
+                        goto error_free_root;
+
+                vm->pasid = pasid;
+        }
+
         return 0;
 
 error_free_root:
@@ -2673,6 +2733,14 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
         bool prt_fini_needed = !!adev->gart.gart_funcs->set_prt;
         int i;
 
+        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);
+        }
+
         amd_sched_entity_fini(vm->entity.sched, &vm->entity);
 
         if (!RB_EMPTY_ROOT(&vm->va)) {
@@ -2752,6 +2820,8 @@ void amdgpu_vm_manager_init(struct amdgpu_device *adev)
         adev->vm_manager.vm_update_mode = 0;
 #endif
 
+        idr_init(&adev->vm_manager.pasid_idr);
+        spin_lock_init(&adev->vm_manager.pasid_lock);
 }
 
 /**
@@ -2765,6 +2835,9 @@ void amdgpu_vm_manager_fini(struct amdgpu_device *adev)
 {
         unsigned i, j;
 
+        WARN_ON(!idr_is_empty(&adev->vm_manager.pasid_idr));
+        idr_destroy(&adev->vm_manager.pasid_idr);
+
         for (i = 0; i < AMDGPU_MAX_VMHUBS; ++i) {
                 struct amdgpu_vm_id_manager *id_mgr =
                         &adev->vm_manager.id_mgr[i];
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,
diff --git a/drivers/gpu/drm/amd/include/kgd_kfd_interface.h b/drivers/gpu/drm/amd/include/kgd_kfd_interface.h
index 94277cb734d2..f516fd10e6ba 100644
--- a/drivers/gpu/drm/amd/include/kgd_kfd_interface.h
+++ b/drivers/gpu/drm/amd/include/kgd_kfd_interface.h
@@ -112,6 +112,9 @@ struct tile_config {
  *
  * @get_max_engine_clock_in_mhz: Retrieves maximum GPU clock in MHz
  *
+ * @alloc_pasid: Allocate a PASID
+ * @free_pasid: Free a PASID
+ *
  * @program_sh_mem_settings: A function that should initiate the memory
  * properties such as main aperture memory type (cache / non cached) and
  * secondary aperture base address, size and memory type.
@@ -160,6 +163,9 @@ struct kfd2kgd_calls {
 
         uint32_t (*get_max_engine_clock_in_mhz)(struct kgd_dev *kgd);
 
+        int (*alloc_pasid)(unsigned int bits);
+        void (*free_pasid)(unsigned int pasid);
+
         /* Register access functions */
         void (*program_sh_mem_settings)(struct kgd_dev *kgd, uint32_t vmid,
                         uint32_t sh_mem_config, uint32_t sh_mem_ape1_base,