drm/amdgpu: Reserved vram for smu to save debug info.

v2: check reserved vram size before allocate.
Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -129,6 +129,7 @@ extern int amdgpu_lbpw;
 extern int amdgpu_compute_multipipe;
 extern int amdgpu_gpu_recovery;
 extern int amdgpu_emu_mode;
+extern uint amdgpu_smu_memory_pool_size;
 
 #ifdef CONFIG_DRM_AMDGPU_SI
 extern int amdgpu_si_support;

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

@@ -690,6 +690,8 @@ void amdgpu_device_gart_location(struct amdgpu_device *adev,
 {
 	u64 size_af, size_bf;
 
+	mc->gart_size += adev->pm.smu_prv_buffer_size;
+
 	size_af = adev->gmc.mc_mask - mc->vram_end;
 	size_bf = mc->vram_start;
 	if (size_bf > size_af) {
@@ -907,6 +909,46 @@ static void amdgpu_device_check_vm_size(struct amdgpu_device *adev)
 	}
 }
 
+static void amdgpu_device_check_smu_prv_buffer_size(struct amdgpu_device *adev)
+{
+	struct sysinfo si;
+	bool is_os_64 = (sizeof(void *) == 8) ? true : false;
+	uint64_t total_memory;
+	uint64_t dram_size_seven_GB = 0x1B8000000;
+	uint64_t dram_size_three_GB = 0xB8000000;
+
+	if (amdgpu_smu_memory_pool_size == 0)
+		return;
+
+	if (!is_os_64) {
+		DRM_WARN("Not 64-bit OS, feature not supported\n");
+		goto def_value;
+	}
+	si_meminfo(&si);
+	total_memory = (uint64_t)si.totalram * si.mem_unit;
+
+	if ((amdgpu_smu_memory_pool_size == 1) ||
+		(amdgpu_smu_memory_pool_size == 2)) {
+		if (total_memory < dram_size_three_GB)
+			goto def_value1;
+	} else if ((amdgpu_smu_memory_pool_size == 4) ||
+		(amdgpu_smu_memory_pool_size == 8)) {
+		if (total_memory < dram_size_seven_GB)
+			goto def_value1;
+	} else {
+		DRM_WARN("Smu memory pool size not supported\n");
+		goto def_value;
+	}
+	adev->pm.smu_prv_buffer_size = amdgpu_smu_memory_pool_size << 28;
+
+	return;
+
+def_value1:
+	DRM_WARN("No enough system memory\n");
+def_value:
+	adev->pm.smu_prv_buffer_size = 0;
+}
+
 /**
  * amdgpu_device_check_arguments - validate module params
  *
@@ -948,6 +990,8 @@ static void amdgpu_device_check_arguments(struct amdgpu_device *adev)
 		amdgpu_vm_fragment_size = -1;
 	}
 
+	amdgpu_device_check_smu_prv_buffer_size(adev);
+
 	amdgpu_device_check_vm_size(adev);
 
 	amdgpu_device_check_block_size(adev);

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

@@ -445,6 +445,8 @@ struct amdgpu_pm {
 	uint32_t                pcie_gen_mask;
 	uint32_t                pcie_mlw_mask;
 	struct amd_pp_display_configuration pm_display_cfg;/* set by dc */
+	uint32_t                smu_prv_buffer_size;
+	struct amdgpu_bo        *smu_prv_buffer;
 };
 
 #define R600_SSTU_DFLT                               0

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

@@ -132,6 +132,7 @@ int amdgpu_lbpw = -1;
 int amdgpu_compute_multipipe = -1;
 int amdgpu_gpu_recovery = -1; /* auto */
 int amdgpu_emu_mode = 0;
+uint amdgpu_smu_memory_pool_size = 0;
 
 MODULE_PARM_DESC(vramlimit, "Restrict VRAM for testing, in megabytes");
 module_param_named(vramlimit, amdgpu_vram_limit, int, 0600);
@@ -316,6 +317,11 @@ MODULE_PARM_DESC(cik_support, "CIK support (1 = enabled (default), 0 = disabled)
 module_param_named(cik_support, amdgpu_cik_support, int, 0444);
 #endif
 
+MODULE_PARM_DESC(smu_memory_pool_size,
+	"reserve gtt for smu debug usage, 0 = disable,"
+		"0x1 = 256Mbyte, 0x2 = 512Mbyte, 0x4 = 1 Gbyte, 0x8 = 2GByte");
+module_param_named(smu_memory_pool_size, amdgpu_smu_memory_pool_size, uint, 0444);
+
 static const struct pci_device_id pciidlist[] = {
 #ifdef  CONFIG_DRM_AMDGPU_SI
 	{0x1002, 0x6780, PCI_ANY_ID, PCI_ANY_ID, 0, 0, CHIP_TAHITI},

drivers/gpu/drm/amd/powerplay/amd_powerplay.c

@@ -145,6 +145,37 @@ static int pp_hw_fini(void *handle)
 	return 0;
 }
 
+static void pp_reserve_vram_for_smu(struct amdgpu_device *adev)
+{
+	int r = -EINVAL;
+	void *cpu_ptr = NULL;
+	uint64_t gpu_addr;
+	struct pp_hwmgr *hwmgr = adev->powerplay.pp_handle;
+
+	if (amdgpu_bo_create_kernel(adev, adev->pm.smu_prv_buffer_size,
+						PAGE_SIZE, AMDGPU_GEM_DOMAIN_GTT,
+						&adev->pm.smu_prv_buffer,
+						&gpu_addr,
+						&cpu_ptr)) {
+		DRM_ERROR("amdgpu: failed to create smu prv buffer\n");
+		return;
+	}
+
+	if (hwmgr->hwmgr_func->notify_cac_buffer_info)
+		r = hwmgr->hwmgr_func->notify_cac_buffer_info(hwmgr,
+					lower_32_bits((unsigned long)cpu_ptr),
+					upper_32_bits((unsigned long)cpu_ptr),
+					lower_32_bits(gpu_addr),
+					upper_32_bits(gpu_addr),
+					adev->pm.smu_prv_buffer_size);
+
+	if (r) {
+		amdgpu_bo_free_kernel(&adev->pm.smu_prv_buffer, NULL, NULL);
+		adev->pm.smu_prv_buffer = NULL;
+		DRM_ERROR("amdgpu: failed to notify SMU buffer address\n");
+	}
+}
+
 static int pp_late_init(void *handle)
 {
 	struct amdgpu_device *adev = handle;
@@ -156,6 +187,8 @@ static int pp_late_init(void *handle)
 					AMD_PP_TASK_COMPLETE_INIT, NULL);
 		mutex_unlock(&hwmgr->smu_lock);
 	}
+	if (adev->pm.smu_prv_buffer_size != 0)
+		pp_reserve_vram_for_smu(adev);
 	return 0;
 }
 
@@ -163,6 +196,8 @@ static void pp_late_fini(void *handle)
 {
 	struct amdgpu_device *adev = handle;
 
+	if (adev->pm.smu_prv_buffer)
+		amdgpu_bo_free_kernel(&adev->pm.smu_prv_buffer, NULL, NULL);
 	amd_powerplay_destroy(adev);
 }