drm/amdgpu: added AMD GPU instance counting V2

Count all GPU instances from AMD(including iGPUs and
dGPUs) in the system.

V2: drop unnecessary initialization for other gpu_info
    members except mutex
Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -81,6 +81,23 @@
 #include "amdgpu_bo_list.h"
 #include "amdgpu_gem.h"
 
+#define MAX_GPU_INSTANCE		16
+
+struct amdgpu_gpu_instance
+{
+	struct amdgpu_device		*adev;
+	int				mgpu_fan_enabled;
+};
+
+struct amdgpu_mgpu_info
+{
+	struct amdgpu_gpu_instance	gpu_ins[MAX_GPU_INSTANCE];
+	struct mutex			mutex;
+	uint32_t			num_gpu;
+	uint32_t			num_dgpu;
+	uint32_t			num_apu;
+};
+
 /*
  * Modules parameters.
  */
@@ -134,6 +151,7 @@ extern int amdgpu_compute_multipipe;
 extern int amdgpu_gpu_recovery;
 extern int amdgpu_emu_mode;
 extern uint amdgpu_smu_memory_pool_size;
+extern struct amdgpu_mgpu_info mgpu_info;
 
 #ifdef CONFIG_DRM_AMDGPU_SI
 extern int amdgpu_si_support;

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

@@ -127,6 +127,9 @@ int amdgpu_compute_multipipe = -1;
 int amdgpu_gpu_recovery = -1; /* auto */
 int amdgpu_emu_mode = 0;
 uint amdgpu_smu_memory_pool_size = 0;
+struct amdgpu_mgpu_info mgpu_info = {
+	.mutex = __MUTEX_INITIALIZER(mgpu_info.mutex),
+};
 
 /**
  * DOC: vramlimit (int)

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

@@ -40,6 +40,30 @@
 #include "amdgpu_gem.h"
 #include "amdgpu_display.h"
 
+static void amdgpu_unregister_gpu_instance(struct amdgpu_device *adev)
+{
+	struct amdgpu_gpu_instance *gpu_instance;
+	int i;
+
+	mutex_lock(&mgpu_info.mutex);
+
+	for (i = 0; i < mgpu_info.num_gpu; i++) {
+		gpu_instance = &(mgpu_info.gpu_ins[i]);
+		if (gpu_instance->adev == adev) {
+			mgpu_info.gpu_ins[i] =
+				mgpu_info.gpu_ins[mgpu_info.num_gpu - 1];
+			mgpu_info.num_gpu--;
+			if (adev->flags & AMD_IS_APU)
+				mgpu_info.num_apu--;
+			else
+				mgpu_info.num_dgpu--;
+			break;
+		}
+	}
+
+	mutex_unlock(&mgpu_info.mutex);
+}
+
 /**
  * amdgpu_driver_unload_kms - Main unload function for KMS.
  *
@@ -55,6 +79,8 @@ void amdgpu_driver_unload_kms(struct drm_device *dev)
 	if (adev == NULL)
 		return;
 
+	amdgpu_unregister_gpu_instance(adev);
+
 	if (adev->rmmio == NULL)
 		goto done_free;
 
@@ -75,6 +101,31 @@ void amdgpu_driver_unload_kms(struct drm_device *dev)
 	dev->dev_private = NULL;
 }
 
+static void amdgpu_register_gpu_instance(struct amdgpu_device *adev)
+{
+	struct amdgpu_gpu_instance *gpu_instance;
+
+	mutex_lock(&mgpu_info.mutex);
+
+	if (mgpu_info.num_gpu >= MAX_GPU_INSTANCE) {
+		DRM_ERROR("Cannot register more gpu instance\n");
+		mutex_unlock(&mgpu_info.mutex);
+		return;
+	}
+
+	gpu_instance = &(mgpu_info.gpu_ins[mgpu_info.num_gpu]);
+	gpu_instance->adev = adev;
+	gpu_instance->mgpu_fan_enabled = 0;
+
+	mgpu_info.num_gpu++;
+	if (adev->flags & AMD_IS_APU)
+		mgpu_info.num_apu++;
+	else
+		mgpu_info.num_dgpu++;
+
+	mutex_unlock(&mgpu_info.mutex);
+}
+
 /**
  * amdgpu_driver_load_kms - Main load function for KMS.
  *
@@ -169,6 +220,7 @@ int amdgpu_driver_load_kms(struct drm_device *dev, unsigned long flags)
 		pm_runtime_put_autosuspend(dev->dev);
 	}
 
+	amdgpu_register_gpu_instance(adev);
 out:
 	if (r) {
 		/* balance pm_runtime_get_sync in amdgpu_driver_unload_kms */