drm/amdgpu: add function to check tmz capability (v4)

Add a function to check tmz capability with kernel parameter and ASIC type.

v2: use a per device tmz variable instead of global amdgpu_tmz.
v3: refine the comments for the function. (Luben)
v4: add amdgpu_tmz.c/h for future use.

Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/Makefile

@@ -55,7 +55,7 @@ amdgpu-y += amdgpu_device.o amdgpu_kms.o \
 	amdgpu_vf_error.o amdgpu_sched.o amdgpu_debugfs.o amdgpu_ids.o \
 	amdgpu_gmc.o amdgpu_mmhub.o amdgpu_xgmi.o amdgpu_csa.o amdgpu_ras.o amdgpu_vm_cpu.o \
 	amdgpu_vm_sdma.o amdgpu_discovery.o amdgpu_ras_eeprom.o amdgpu_nbio.o \
-	amdgpu_umc.o smu_v11_0_i2c.o amdgpu_fru_eeprom.o
+	amdgpu_umc.o smu_v11_0_i2c.o amdgpu_fru_eeprom.o amdgpu_tmz.o
 
 amdgpu-$(CONFIG_PERF_EVENTS) += amdgpu_pmu.o
 

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -65,6 +65,7 @@
 #include "amdgpu_ras.h"
 #include "amdgpu_pmu.h"
 #include "amdgpu_fru_eeprom.h"
+#include "amdgpu_tmz.h"
 
 #include <linux/suspend.h>
 #include <drm/task_barrier.h>
@@ -1140,6 +1141,8 @@ static int amdgpu_device_check_arguments(struct amdgpu_device *adev)
 
 	adev->firmware.load_type = amdgpu_ucode_get_load_type(adev, amdgpu_fw_load_type);
 
+	adev->tmz.enabled = amdgpu_is_tmz(adev);
+
 	return 0;
 }
 

drivers/gpu/drm/amd/amdgpu/amdgpu_tmz.c

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2019 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <drm/drmP.h>
+#include "amdgpu.h"
+#include "amdgpu_tmz.h"
+
+
+/**
+ * amdgpu_is_tmz - validate trust memory zone
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * Return true if @dev supports trusted memory zones (TMZ), and return false if
+ * @dev does not support TMZ.
+ */
+bool amdgpu_is_tmz(struct amdgpu_device *adev)
+{
+	if (!amdgpu_tmz)
+		return false;
+
+	if (adev->asic_type < CHIP_RAVEN || adev->asic_type == CHIP_ARCTURUS) {
+		dev_warn(adev->dev, "doesn't support trusted memory zones (TMZ)\n");
+		return false;
+	}
+
+	dev_info(adev->dev, "TMZ feature is enabled\n");
+
+	return true;
+}

drivers/gpu/drm/amd/amdgpu/amdgpu_tmz.h

@@ -33,4 +33,7 @@ struct amdgpu_tmz {
 	bool	enabled;
 };
 
+
+extern bool amdgpu_is_tmz(struct amdgpu_device *adev);
+
 #endif