[PATCH 7.1 226/271] Revert "drm/amdgpu: fix aperture mapping leak"

7.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Asad Kamal <[email protected]>

commit b96c529cd2551b78316a4afa3237b2ed96ba03c8 upstream.

devres teardown is LIFO. The aperture devres node was registered after
the DRM device node, so devres_release_all() unmaps the aperture before
the DRM device release callback fires amdgpu_device_fini_sw(). IP
sw_fini callbacks (e.g. vcn_v4_0_sw_fini) write to fw_shared through a
pointer derived from aper_base_kaddr, causing a kernel page fault on
probe failure / rollback:

  BUG: unable to handle page fault ... PMD 0
  RIP: vcn_v4_0_sw_fini+0x7b/0x170 [amdgpu]
  Call Trace:
    amdgpu_device_fini_sw
    amdgpu_driver_release_kms
    devm_drm_dev_init_release
    devres_release_all

This reverts commit d871e99879cb5fd1fa798b006b4888887e63a17a.

Fixes: d871e99879cb ("drm/amdgpu: fix aperture mapping leak")
Reported-by: Yuansheng Mao <[email protected]>
Signed-off-by: Asad Kamal <[email protected]>
Reviewed-by: Lijo Lazar <[email protected]>
Reviewed-by: Hawking Zhang <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
(cherry picked from commit 336e0cd576817ac64a4b394ca2b3680029f3e37f)
Cc: [email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c |    2 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c    |   35 +++++++++++++++--------------
 2 files changed, 21 insertions(+), 16 deletions(-)

--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -4169,6 +4169,8 @@ static void amdgpu_device_unmap_mmio(str
 
 	iounmap(adev->rmmio);
 	adev->rmmio = NULL;
+	if (adev->mman.aper_base_kaddr)
+		iounmap(adev->mman.aper_base_kaddr);
 	adev->mman.aper_base_kaddr = NULL;
 
 	/* Memory manager related */
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -2121,23 +2121,17 @@ int amdgpu_ttm_init(struct amdgpu_device
 	/* Change the size here instead of the init above so only lpfn is affected */
 	amdgpu_ttm_set_buffer_funcs_status(adev, false);
 #ifdef CONFIG_64BIT
-	if (adev->gmc.xgmi.connected_to_cpu) {
-		void *kaddr = devm_memremap(adev->dev, adev->gmc.aper_base,
-					    adev->gmc.visible_vram_size,
-					    MEMREMAP_WB);
-		if (IS_ERR(kaddr))
-			return PTR_ERR(kaddr);
-		adev->mman.aper_base_kaddr = (__force void __iomem *)kaddr;
-	} else if (adev->gmc.is_app_apu) {
+#ifdef CONFIG_X86
+	if (adev->gmc.xgmi.connected_to_cpu)
+		adev->mman.aper_base_kaddr = ioremap_cache(adev->gmc.aper_base,
+				adev->gmc.visible_vram_size);
+	else if (adev->gmc.is_app_apu)
 		DRM_DEBUG_DRIVER(
 			"No need to ioremap when real vram size is 0\n");
-	} else {
-		adev->mman.aper_base_kaddr = devm_ioremap_wc(adev->dev,
-							     adev->gmc.aper_base,
-							     adev->gmc.visible_vram_size);
-		if (!adev->mman.aper_base_kaddr)
-			return -ENOMEM;
-	}
+	else
+#endif
+		adev->mman.aper_base_kaddr = ioremap_wc(adev->gmc.aper_base,
+				adev->gmc.visible_vram_size);
 #endif
 
 	amdgpu_ttm_init_vram_resv_regions(adev);
@@ -2266,6 +2260,8 @@ int amdgpu_ttm_init(struct amdgpu_device
  */
 void amdgpu_ttm_fini(struct amdgpu_device *adev)
 {
+	int idx;
+
 	if (!adev->mman.initialized)
 		return;
 
@@ -2288,7 +2284,14 @@ void amdgpu_ttm_fini(struct amdgpu_devic
 	amdgpu_ttm_unmark_vram_reserved(adev, AMDGPU_RESV_FW_VRAM_USAGE);
 	amdgpu_ttm_unmark_vram_reserved(adev, AMDGPU_RESV_DRV_VRAM_USAGE);
 
-	adev->mman.aper_base_kaddr = NULL;
+	if (drm_dev_enter(adev_to_drm(adev), &idx)) {
+
+		if (adev->mman.aper_base_kaddr)
+			iounmap(adev->mman.aper_base_kaddr);
+		adev->mman.aper_base_kaddr = NULL;
+
+		drm_dev_exit(idx);
+	}
 
 	if (!adev->gmc.is_app_apu)
 		amdgpu_vram_mgr_fini(adev);