drm/amdkfd: Expose HDP registers to user space

Introduce a new memory type (KFD_IOC_ALLOC_MEM_FLAGS_MMIO_REMAP) and
expose mmio page of HDP registers to user space through this new
memory type.

v2: moved remapped hdp regs to adev struct
v3: rename the new memory type to ALLOC_MEM_FLAGS_MMIO_REMAP
v4: use more generic function name
v5: Fail remapped mmio allocation for asics before gfx9

Signed-off-by: Oak Zeng <Oak.Zeng@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

6 files changed, 20 insertions, 3 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
index aeead072fa79..401edb605fdd 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
@@ -519,6 +519,13 @@ uint64_t amdgpu_amdkfd_get_hive_id(struct kgd_dev *kgd)
         return adev->gmc.xgmi.hive_id;
 }
 
+uint64_t amdgpu_amdkfd_get_mmio_remap_phys_addr(struct kgd_dev *kgd)
+{
+        struct amdgpu_device *adev = (struct amdgpu_device *)kgd;
+
+        return adev->rmmio_remap.bus_addr;
+}
+
 int amdgpu_amdkfd_submit_ib(struct kgd_dev *kgd, enum kgd_engine_type engine,
                                 uint32_t vmid, uint64_t gpu_addr,
                                 uint32_t *ib_cmd, uint32_t ib_len)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
index 4e37fa7e85b1..ea1f141db3ff 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
@@ -169,6 +169,7 @@ int amdgpu_amdkfd_get_dmabuf_info(struct kgd_dev *kgd, int dma_buf_fd,
                                   uint32_t *flags);
 uint64_t amdgpu_amdkfd_get_vram_usage(struct kgd_dev *kgd);
 uint64_t amdgpu_amdkfd_get_hive_id(struct kgd_dev *kgd);
+uint64_t amdgpu_amdkfd_get_mmio_remap_phys_addr(struct kgd_dev *kgd);
 
 #define read_user_wptr(mmptr, wptr, dst)                                \
         ({                                                              \
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index a6e5184d436c..00e013581a70 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -1109,7 +1109,8 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
                 if (!offset || !*offset)
                         return -EINVAL;
                 user_addr = *offset;
-        } else if (flags & ALLOC_MEM_FLAGS_DOORBELL) {
+        } else if (flags & (ALLOC_MEM_FLAGS_DOORBELL |
+                        ALLOC_MEM_FLAGS_MMIO_REMAP)) {
                 domain = AMDGPU_GEM_DOMAIN_GTT;
                 alloc_domain = AMDGPU_GEM_DOMAIN_CPU;
                 bo_type = ttm_bo_type_sg;
@@ -1294,8 +1295,8 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu(
         /* Free the sync object */
         amdgpu_sync_free(&mem->sync);
 
-        /* If the SG is not NULL, it's one we created for a doorbell
-         * BO. We need to free it.
+        /* If the SG is not NULL, it's one we created for a doorbell or mmio
+         * remap BO. We need to free it.
          */
         if (mem->bo->tbo.sg) {
                 sg_free_table(mem->bo->tbo.sg);
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index 083bd8114db1..d795e5018270 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -1272,6 +1272,12 @@ static int kfd_ioctl_alloc_memory_of_gpu(struct file *filep,
                 if (args->size != kfd_doorbell_process_slice(dev))
                         return -EINVAL;
                 offset = kfd_get_process_doorbells(dev, p);
+        } else if (flags & KFD_IOC_ALLOC_MEM_FLAGS_MMIO_REMAP) {
+                if (args->size != PAGE_SIZE)
+                        return -EINVAL;
+                offset = amdgpu_amdkfd_get_mmio_remap_phys_addr(dev->kgd);
+                if (!offset)
+                        return -ENOMEM;
         }
 
         mutex_lock(&p->mutex);
diff --git a/drivers/gpu/drm/amd/include/kgd_kfd_interface.h b/drivers/gpu/drm/amd/include/kgd_kfd_interface.h
index b897aca9b4c9..98b9533e672b 100644
--- a/drivers/gpu/drm/amd/include/kgd_kfd_interface.h
+++ b/drivers/gpu/drm/amd/include/kgd_kfd_interface.h
@@ -174,6 +174,7 @@ struct tile_config {
 #define ALLOC_MEM_FLAGS_GTT             (1 << 1)
 #define ALLOC_MEM_FLAGS_USERPTR         (1 << 2)
 #define ALLOC_MEM_FLAGS_DOORBELL        (1 << 3)
+#define ALLOC_MEM_FLAGS_MMIO_REMAP      (1 << 4)
 
 /*
  * Allocation flags attributes/access options.
diff --git a/include/uapi/linux/kfd_ioctl.h b/include/uapi/linux/kfd_ioctl.h
index bb1b4280f53d..1e7d5f3376b0 100644
--- a/include/uapi/linux/kfd_ioctl.h
+++ b/include/uapi/linux/kfd_ioctl.h
@@ -338,6 +338,7 @@ struct kfd_ioctl_acquire_vm_args {
 #define KFD_IOC_ALLOC_MEM_FLAGS_GTT             (1 << 1)
 #define KFD_IOC_ALLOC_MEM_FLAGS_USERPTR         (1 << 2)
 #define KFD_IOC_ALLOC_MEM_FLAGS_DOORBELL        (1 << 3)
+#define KFD_IOC_ALLOC_MEM_FLAGS_MMIO_REMAP      (1 << 4)
 /* Allocation flags: attributes/access options */
 #define KFD_IOC_ALLOC_MEM_FLAGS_WRITABLE        (1 << 31)
 #define KFD_IOC_ALLOC_MEM_FLAGS_EXECUTABLE      (1 << 30)