[PATCH 1/2] Revert "drm/amdgpu: TA unload messages are not actually sent to psp when amdgpu is uninstalled"

[PATCH 1/2] Revert "drm/amdgpu: TA unload messages are not actually sent to psp when amdgpu is uninstalled"

[vitaly.prosyak]

From: Vitaly Prosyak <vitaly.prosyak@amd.com>

This reverts commit fac53471d0ea9693d314aa2df08d62b2e7e3a0f8.
The following change: move the drm_dev_unplug call after
amdgpu_driver_unload_kms in amdgpu_pci_remove. The reason is
the following: amdgpu_pci_remove calls drm_dev_unregister
and it should be called first to ensure userspace can't access the
device instance anymore. If we call drm_dev_unplug after
amdgpu_driver_unload_kms then we observe IGT PCI software unplug
test failure (kernel hung) for all ASICs. This is how this
regression was found.

After this revert, the following commands do work not, but it would
be fixed in the next commit:
 - sudo modprobe -r amdgpu
 - sudo modeprobe amdgpu

Signed-off-by: Vitaly Prosyak <vitaly.prosyak@amd.com>
Reviewed-by Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 3 ++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c    | 4 ++--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index efd4f8226120..58d445a0590f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -4019,7 +4019,8 @@ void amdgpu_device_fini_hw(struct amdgpu_device *adev)
 
 	amdgpu_gart_dummy_page_fini(adev);
 
-	amdgpu_device_unmap_mmio(adev);
+	if (drm_dev_is_unplugged(adev_to_drm(adev)))
+		amdgpu_device_unmap_mmio(adev);
 
 }
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index a75dba2caeca..7edbaa90fac9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -2227,6 +2227,8 @@ amdgpu_pci_remove(struct pci_dev *pdev)
 	struct drm_device *dev = pci_get_drvdata(pdev);
 	struct amdgpu_device *adev = drm_to_adev(dev);
 
+	drm_dev_unplug(dev);
+
 	if (adev->pm.rpm_mode != AMDGPU_RUNPM_NONE) {
 		pm_runtime_get_sync(dev->dev);
 		pm_runtime_forbid(dev->dev);
@@ -2266,8 +2268,6 @@ amdgpu_pci_remove(struct pci_dev *pdev)
 
 	amdgpu_driver_unload_kms(dev);
 
-	drm_dev_unplug(dev);
-
 	/*
 	 * Flush any in flight DMA operations from device.
 	 * Clear the Bus Master Enable bit and then wait on the PCIe Device
-- 
2.25.1

[PATCH 2/2] drm/amdgpu: always sending PSP messages LOAD_ASD and UNLOAD_TA

[vitaly.prosyak]

From: Vitaly Prosyak <vitaly.prosyak@amd.com>

We allow sending PSP messages LOAD_ASD and UNLOAD_TA without acquiring a lock
in drm_dev_enter during driver unload because we must call drm_dev_unplug as the
beginning  of unload driver sequence.
Added WARNING if other PSP messages are sent without a lock.
After this commit, the following commands would work
 -sudo modprobe -r amdgpu
 -sudo modeprobe amdgpu

Signed-off-by: Vitaly Prosyak <vitaly.prosyak@amd.com>
Reviewed-by Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
index a8391f269cd0..7ef18e062c0e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
@@ -606,12 +606,21 @@ psp_cmd_submit_buf(struct psp_context *psp,
 	int timeout = 20000;
 	bool ras_intr = false;
 	bool skip_unsupport = false;
+	bool dev_entered;
 
 	if (psp->adev->no_hw_access)
 		return 0;
 
-	if (!drm_dev_enter(adev_to_drm(psp->adev), &idx))
-		return 0;
+	dev_entered = drm_dev_enter(adev_to_drm(psp->adev), &idx);
+	/*
+	 * We allow sending PSP messages LOAD_ASD and UNLOAD_TA without acquiring
+	 * a lock in drm_dev_enter during driver unload because we must call
+	 * drm_dev_unplug as the beginning  of unload driver sequence . It is very
+	 * crucial that userspace can't access device instances anymore.
+	 */
+	if (!dev_entered)
+		WARN_ON(psp->cmd_buf_mem->cmd_id != GFX_CMD_ID_LOAD_ASD &&
+				psp->cmd_buf_mem->cmd_id != GFX_CMD_ID_UNLOAD_TA);
 
 	memset(psp->cmd_buf_mem, 0, PSP_CMD_BUFFER_SIZE);
 
@@ -676,7 +685,8 @@ psp_cmd_submit_buf(struct psp_context *psp,
 	}
 
 exit:
-	drm_dev_exit(idx);
+	if (dev_entered == true )
+		drm_dev_exit(idx);
 	return ret;
 }
 
-- 
2.25.1