Re: [PATCH] drm/amdgpu: Delay unmapping MMIO VRAM to amdgpu_ttm_fini() in GPU initialization failure

[Andrey Grodzovsky]

On 2022-01-03 9:30 p.m., Leslie Shi wrote:
If the driver loads failed during hw_init(), delay unmapping MMIO VRAM to 
amdgpu_ttm_fini().
Its prevents accessing invalid memory address in vcn_v3_0_sw_fini().
Signed-off-by: Leslie Shi <yuliang....@amd.com>
---
  drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 16 +++++++++-------
  drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c    |  4 ++++
  2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index ce93a304292c..d6006de57af5 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -3830,7 +3830,7 @@ int amdgpu_device_init(struct amdgpu_device *adev,
        return r;
  }
  
-static void amdgpu_device_unmap_mmio(struct amdgpu_device *adev)
+static void amdgpu_device_unmap_mmio(struct amdgpu_device *adev, bool 
unmap_mmio_vram)
  {
        /* Clear all CPU mappings pointing to this device */
        unmap_mapping_range(adev->ddev.anon_inode->i_mapping, 0, 0, 1);
@@ -3840,9 +3840,12 @@ static void amdgpu_device_unmap_mmio(struct 
amdgpu_device *adev)
  
  	iounmap(adev->rmmio);
        adev->rmmio = NULL;
-       if (adev->mman.aper_base_kaddr)
-               iounmap(adev->mman.aper_base_kaddr);
-       adev->mman.aper_base_kaddr = NULL;


Why only VRAM ? Why not register BAR above ? In general I don't see why 
not just follow
what i suggested here https://www.spinics.net/lists/amd-gfx/msg72217.html

Andrey


+
+       if (unmap_mmio_vram) {
+               if (adev->mman.aper_base_kaddr)
+                       iounmap(adev->mman.aper_base_kaddr);
+               adev->mman.aper_base_kaddr = NULL;
+       }
  
  	/* Memory manager related */
        if (!adev->gmc.xgmi.connected_to_cpu) {
@@ -3905,8 +3908,7 @@ void amdgpu_device_fini_hw(struct amdgpu_device *adev)
  
  	amdgpu_gart_dummy_page_fini(adev);
  
-	if (drm_dev_is_unplugged(adev_to_drm(adev)))
-               amdgpu_device_unmap_mmio(adev);
+       amdgpu_device_unmap_mmio(adev, drm_dev_is_unplugged(adev_to_drm(adev)));
  
  }
  
@@ -5727,7 +5729,7 @@ void amdgpu_device_halt(struct amdgpu_device *adev)
  
  	adev->no_hw_access = true;
  
-	amdgpu_device_unmap_mmio(adev);
+       amdgpu_device_unmap_mmio(adev, true);
  
  	pci_disable_device(pdev);
        pci_wait_for_pending_transaction(pdev);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 367abed1d6e6..67cd12caf019 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1815,6 +1815,10 @@ void amdgpu_ttm_fini(struct amdgpu_device *adev)
                                      NULL, NULL);
        amdgpu_ttm_fw_reserve_vram_fini(adev);
  
+        if (adev->mman.aper_base_kaddr)
+                iounmap(adev->mman.aper_base_kaddr);
+        adev->mman.aper_base_kaddr = NULL;
+
        amdgpu_vram_mgr_fini(adev);
        amdgpu_gtt_mgr_fini(adev);
        amdgpu_preempt_mgr_fini(adev);