[PATCH V2 1/2] drm/amdgpu: Acquire ttm locks for dmaunmap

[David Francis]

dmaunmap can call ttm_bo_validate, which expects the
ttm dma_resv to be held.

Acquire the locks in amdgpu_amdkfd_gpuvm_dmaunmap_mem.

Because the dmaunmap step can now fail, the unmap ioctl UAPI
needs two new arguments. n_dmaunmap_success tracks the number
of devices that have completed dmaunmap. If a device fails
to dmaunmap due to a signal interrupt, n_dmaunmap_bos tracks
the number of bos on that device that were successfully
dmaunmapped.

This failure can also cause the sync_memory step of the ioctl
to be repeated; it is idempotent, so this should not cause any issues.

Signed-off-by: David Francis <David.Francis at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h    |  2 +-
 .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c  | 23 +++++++++++++++----
 drivers/gpu/drm/amd/amdkfd/kfd_chardev.c      | 14 +++++++++--
 include/uapi/linux/kfd_ioctl.h                |  2 ++
 4 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
index 3ad8dc523b42..781642871900 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
@@ -302,7 +302,7 @@ int amdgpu_amdkfd_gpuvm_map_memory_to_gpu(struct amdgpu_device *adev,
 					  struct kgd_mem *mem, void *drm_priv);
 int amdgpu_amdkfd_gpuvm_unmap_memory_from_gpu(
 		struct amdgpu_device *adev, struct kgd_mem *mem, void *drm_priv);
-void amdgpu_amdkfd_gpuvm_dmaunmap_mem(struct kgd_mem *mem, void *drm_priv);
+int amdgpu_amdkfd_gpuvm_dmaunmap_mem(struct kgd_mem *mem, void *drm_priv, uint32_t *num_bos);
 int amdgpu_amdkfd_gpuvm_sync_memory(
 		struct amdgpu_device *adev, struct kgd_mem *mem, bool intr);
 int amdgpu_amdkfd_gpuvm_map_gtt_bo_to_kernel(struct kgd_mem *mem,
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index a15e59abe70a..cbd6032f3d39 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -2094,21 +2094,36 @@ int amdgpu_amdkfd_gpuvm_map_memory_to_gpu(
 	return ret;
 }
 
-void amdgpu_amdkfd_gpuvm_dmaunmap_mem(struct kgd_mem *mem, void *drm_priv)
+int amdgpu_amdkfd_gpuvm_dmaunmap_mem(struct kgd_mem *mem, void *drm_priv, uint32_t *num_bos)
 {
 	struct kfd_mem_attachment *entry;
 	struct amdgpu_vm *vm;
+	int ret;
+	int i = 0;
 
 	vm = drm_priv_to_vm(drm_priv);
 
 	mutex_lock(&mem->lock);
 
 	list_for_each_entry(entry, &mem->attachments, list) {
-		if (entry->bo_va->base.vm == vm)
-			kfd_mem_dmaunmap_attachment(mem, entry);
-	}
+		if (i >= *num_bos) {
+			ret = amdgpu_bo_reserve(entry->bo_va->base.bo, false);
+			if (ret) {
+				*num_bos = i;
+				goto out;
+			}
+
+			if (entry->bo_va->base.vm == vm)
+				kfd_mem_dmaunmap_attachment(mem, entry);
 
+			amdgpu_bo_unreserve(entry->bo_va->base.bo);
+		}
+		i++;
+	}
+	*num_bos = 0;
+out:
 	mutex_unlock(&mem->lock);
+	return ret;
 }
 
 int amdgpu_amdkfd_gpuvm_unmap_memory_from_gpu(
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index 06988cf1db51..a944e255de4a 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -1379,6 +1379,10 @@ static int kfd_ioctl_unmap_memory_from_gpu(struct file *filep,
 		pr_debug("n_success exceeds n_devices\n");
 		return -EINVAL;
 	}
+	if (args->n_dmaunmap_success > args->n_devices) {
+		pr_debug("n_dmaunmap_success exceeds n_devices\n");
+		return -EINVAL;
+	}
 
 	devices_arr = kmalloc_array(args->n_devices, sizeof(*devices_arr),
 				    GFP_KERNEL);
@@ -1434,7 +1438,7 @@ static int kfd_ioctl_unmap_memory_from_gpu(struct file *filep,
 	}
 
 	/* Flush TLBs after waiting for the page table updates to complete */
-	for (i = 0; i < args->n_devices; i++) {
+	for (i = args->n_dmaunmap_success; i < args->n_devices; i++) {
 		peer_pdd = kfd_process_device_data_by_id(p, devices_arr[i]);
 		if (WARN_ON_ONCE(!peer_pdd))
 			continue;
@@ -1442,7 +1446,12 @@ static int kfd_ioctl_unmap_memory_from_gpu(struct file *filep,
 			kfd_flush_tlb(peer_pdd, TLB_FLUSH_HEAVYWEIGHT);
 
 		/* Remove dma mapping after tlb flush to avoid IO_PAGE_FAULT */
-		amdgpu_amdkfd_gpuvm_dmaunmap_mem(mem, peer_pdd->drm_priv);
+		err = amdgpu_amdkfd_gpuvm_dmaunmap_mem(mem, peer_pdd->drm_priv, &args->n_dmaunmap_bos);
+		if (err) {
+			pr_debug("DMA unmapping failed, acquire interrupted by user signal\n");
+			goto dmaunmap_failed;
+		}
+		args->n_dmaunmap_success = i+1;
 	}
 
 	mutex_unlock(&p->mutex);
@@ -1455,6 +1464,7 @@ static int kfd_ioctl_unmap_memory_from_gpu(struct file *filep,
 get_mem_obj_from_handle_failed:
 unmap_memory_from_gpu_failed:
 sync_memory_failed:
+dmaunmap_failed:
 	mutex_unlock(&p->mutex);
 copy_from_user_failed:
 	kfree(devices_arr);
diff --git a/include/uapi/linux/kfd_ioctl.h b/include/uapi/linux/kfd_ioctl.h
index f0ed68974c54..edeeac370201 100644
--- a/include/uapi/linux/kfd_ioctl.h
+++ b/include/uapi/linux/kfd_ioctl.h
@@ -467,6 +467,8 @@ struct kfd_ioctl_unmap_memory_from_gpu_args {
 	__u64 device_ids_array_ptr;	/* to KFD */
 	__u32 n_devices;		/* to KFD */
 	__u32 n_success;		/* to/from KFD */
+	__u32 n_dmaunmap_success;	/* to/from KFD */
+	__u32 n_dmaunmap_bos;		/* to/from KFD */
 };
 
 /* Allocate GWS for specific queue
-- 
2.34.1