[PATCH 1/1] drm/amdgpu: convert gtt_window_lock to a spinlock

[Nirmoy Das]

amdgpu_device_gpu_recover() will eventually call
gmc_v10_0_flush_gpu_tlb() with holding a spinlock, which
puts the process in atomic context. Sleeping in atomic context
is not allowed so convert gtt_window_lock into a spinlock.

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:935
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2662, name: cat
Call Trace:
 dump_stack+0x8b/0xb0
 ___might_sleep.cold+0xb6/0xc6
 ? gmc_v10_0_flush_gpu_tlb+0x72/0x2c0 [amdgpu]
 __mutex_lock+0x45/0x820
 ? amdgpu_device_skip_hw_access+0x3e/0x70 [amdgpu]
 gmc_v10_0_flush_gpu_tlb+0x72/0x2c0 [amdgpu]
 ? amdgpu_device_skip_hw_access+0x3e/0x70 [amdgpu]
 amdgpu_gart_bind+0x7a/0xc0 [amdgpu]
 amdgpu_ttm_gart_bind+0x7d/0xd0 [amdgpu]
 ? amdgpu_ttm_recover_gart+0x2e/0x70 [amdgpu]
 amdgpu_gtt_mgr_recover+0x4e/0x70 [amdgpu]
 amdgpu_do_asic_reset.cold+0x90/0x1c4 [amdgpu]
 ? amdgpu_device_pre_asic_reset+0xa8/0x250 [amdgpu]
 amdgpu_device_gpu_recover.cold+0x7bd/0xa23 [amdgpu]
 ? lock_acquired+0x210/0x390
 gpu_recover_get+0x29/0x60 [amdgpu]
 simple_attr_read+0x69/0xf0
 debugfs_attr_read+0x40/0x60
 full_proxy_read+0x56/0x80
 vfs_read+0xd1/0x1d0
 ksys_read+0x68/0xe0
 do_syscall_64+0x33/0x80
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Signed-off-by: Nirmoy Das <nirmoy.das at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c  |  6 +++---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h  |  2 +-
 drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c   | 10 +++++-----
 drivers/gpu/drm/amd/amdkfd/kfd_migrate.c |  4 ++--
 4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index c0aef327292a..4cb8fd193b6c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -333,7 +333,7 @@ int amdgpu_ttm_copy_mem_to_mem(struct amdgpu_device *adev,
 	amdgpu_res_first(src->mem, src->offset, size, &src_mm);
 	amdgpu_res_first(dst->mem, dst->offset, size, &dst_mm);
 
-	mutex_lock(&adev->mman.gtt_window_lock);
+	spin_lock(&adev->mman.gtt_window_lock);
 	while (src_mm.remaining) {
 		uint32_t src_page_offset = src_mm.start & ~PAGE_MASK;
 		uint32_t dst_page_offset = dst_mm.start & ~PAGE_MASK;
@@ -373,7 +373,7 @@ int amdgpu_ttm_copy_mem_to_mem(struct amdgpu_device *adev,
 		amdgpu_res_next(&dst_mm, cur_size);
 	}
 error:
-	mutex_unlock(&adev->mman.gtt_window_lock);
+	spin_unlock(&adev->mman.gtt_window_lock);
 	if (f)
 		*f = dma_fence_get(fence);
 	dma_fence_put(fence);
@@ -1661,7 +1661,7 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
 	int r;
 	u64 vis_vram_limit;
 
-	mutex_init(&adev->mman.gtt_window_lock);
+	spin_lock_init(&adev->mman.gtt_window_lock);
 
 	/* No others user of address space so set it to 0 */
 	r = ttm_device_init(&adev->mman.bdev, &amdgpu_bo_driver, adev->dev,
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
index 2877a924086f..afd905dc337b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
@@ -70,7 +70,7 @@ struct amdgpu_mman {
 	struct amdgpu_ring			*buffer_funcs_ring;
 	bool					buffer_funcs_enabled;
 
-	struct mutex				gtt_window_lock;
+	spinlock_t				gtt_window_lock;
 	/* Scheduler entity for buffer moves */
 	struct drm_sched_entity			entity;
 
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c
index ceab5ef50790..f4ce3eb4d7e4 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c
@@ -341,11 +341,11 @@ static void gmc_v10_0_flush_gpu_tlb(struct amdgpu_device *adev, uint32_t vmid,
 		return;
 	}
 
-	mutex_lock(&adev->mman.gtt_window_lock);
+	spin_lock(&adev->mman.gtt_window_lock);
 
 	if (vmhub == AMDGPU_MMHUB_0) {
 		gmc_v10_0_flush_vm_hub(adev, vmid, AMDGPU_MMHUB_0, 0);
-		mutex_unlock(&adev->mman.gtt_window_lock);
+		spin_unlock(&adev->mman.gtt_window_lock);
 		return;
 	}
 
@@ -356,7 +356,7 @@ static void gmc_v10_0_flush_gpu_tlb(struct amdgpu_device *adev, uint32_t vmid,
 	    amdgpu_in_reset(adev) ||
 	    ring->sched.ready == false) {
 		gmc_v10_0_flush_vm_hub(adev, vmid, AMDGPU_GFXHUB_0, 0);
-		mutex_unlock(&adev->mman.gtt_window_lock);
+		spin_unlock(&adev->mman.gtt_window_lock);
 		return;
 	}
 
@@ -379,7 +379,7 @@ static void gmc_v10_0_flush_gpu_tlb(struct amdgpu_device *adev, uint32_t vmid,
 	if (r)
 		goto error_submit;
 
-	mutex_unlock(&adev->mman.gtt_window_lock);
+	spin_unlock(&adev->mman.gtt_window_lock);
 
 	dma_fence_wait(fence, false);
 	dma_fence_put(fence);
@@ -390,7 +390,7 @@ static void gmc_v10_0_flush_gpu_tlb(struct amdgpu_device *adev, uint32_t vmid,
 	amdgpu_job_free(job);
 
 error_alloc:
-	mutex_unlock(&adev->mman.gtt_window_lock);
+	spin_unlock(&adev->mman.gtt_window_lock);
 	DRM_ERROR("Error flushing GPU TLB using the SDMA (%d)!\n", r);
 }
 
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
index fd8f544f0de2..e1dad02d400b 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
@@ -135,7 +135,7 @@ svm_migrate_copy_memory_gart(struct amdgpu_device *adev, dma_addr_t *sys,
 	uint64_t size;
 	int r;
 
-	mutex_lock(&adev->mman.gtt_window_lock);
+	spin_lock(&adev->mman.gtt_window_lock);
 
 	while (npages) {
 		size = min(GTT_MAX_PAGES, npages);
@@ -171,7 +171,7 @@ svm_migrate_copy_memory_gart(struct amdgpu_device *adev, dma_addr_t *sys,
 	}
 
 out_unlock:
-	mutex_unlock(&adev->mman.gtt_window_lock);
+	spin_unlock(&adev->mman.gtt_window_lock);
 
 	return r;
 }
-- 
2.31.1