drm/amdkfd: Add device repartition support

GFX9.4.3 will support dynamic repartitioning of the GPU through sysfs.
Add device repartitioning support in KFD to repartition GPU from one
mode to other.

v2: squash in fix ("drm/amdkfd: Fix warning kgd2kfd_unlock_kfd defined but not used")

Signed-off-by: Mukul Joshi <mukul.joshi@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -773,3 +773,13 @@ bool amdgpu_amdkfd_ras_query_utcl2_poison_status(struct amdgpu_device *adev)
 	else
 		return false;
 }
+
+int amdgpu_amdkfd_check_and_lock_kfd(struct amdgpu_device *adev)
+{
+	return kgd2kfd_check_and_lock_kfd();
+}
+
+void amdgpu_amdkfd_unlock_kfd(struct amdgpu_device *adev)
+{
+	kgd2kfd_unlock_kfd();
+}

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

@@ -151,6 +151,8 @@ void amdgpu_amdkfd_interrupt(struct amdgpu_device *adev,
 void amdgpu_amdkfd_device_probe(struct amdgpu_device *adev);
 void amdgpu_amdkfd_device_init(struct amdgpu_device *adev);
 void amdgpu_amdkfd_device_fini_sw(struct amdgpu_device *adev);
+int amdgpu_amdkfd_check_and_lock_kfd(struct amdgpu_device *adev);
+void amdgpu_amdkfd_unlock_kfd(struct amdgpu_device *adev);
 int amdgpu_amdkfd_submit_ib(struct amdgpu_device *adev,
 				enum kgd_engine_type engine,
 				uint32_t vmid, uint64_t gpu_addr,
@@ -373,6 +375,8 @@ int kgd2kfd_post_reset(struct kfd_dev *kfd);
 void kgd2kfd_interrupt(struct kfd_dev *kfd, const void *ih_ring_entry);
 void kgd2kfd_set_sram_ecc_flag(struct kfd_dev *kfd);
 void kgd2kfd_smi_event_throttle(struct kfd_dev *kfd, uint64_t throttle_bitmask);
+int kgd2kfd_check_and_lock_kfd(void);
+void kgd2kfd_unlock_kfd(void);
 #else
 static inline int kgd2kfd_init(void)
 {
@@ -438,5 +442,14 @@ static inline
 void kgd2kfd_smi_event_throttle(struct kfd_dev *kfd, uint64_t throttle_bitmask)
 {
 }
+
+static inline int kgd2kfd_check_and_lock_kfd(void)
+{
+	return 0;
+}
+
+static inline void kgd2kfd_unlock_kfd(void)
+{
+}
 #endif
 #endif /* AMDGPU_AMDKFD_H_INCLUDED */

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

@@ -1233,10 +1233,30 @@ static ssize_t amdgpu_gfx_set_compute_partition(struct device *dev,
 		return -EINVAL;
 	}
 
+	if (!adev->kfd.init_complete)
+		return -EPERM;
+
 	mutex_lock(&adev->gfx.partition_mutex);
 
-	ret = adev->gfx.funcs->switch_partition_mode(adev, mode);
+	if (mode == adev->gfx.funcs->query_partition_mode(adev))
+		goto out;
 
+	ret = amdgpu_amdkfd_check_and_lock_kfd(adev);
+	if (ret)
+		goto out;
+
+	amdgpu_amdkfd_device_fini_sw(adev);
+
+	adev->gfx.funcs->switch_partition_mode(adev, mode);
+
+	amdgpu_amdkfd_device_probe(adev);
+	amdgpu_amdkfd_device_init(adev);
+	/* If KFD init failed, return failure */
+	if (!adev->kfd.init_complete)
+		ret = -EIO;
+
+	amdgpu_amdkfd_unlock_kfd(adev);
+out:
 	mutex_unlock(&adev->gfx.partition_mutex);
 
 	if (ret)

drivers/gpu/drm/amd/amdgpu/gfx_v9_4_3.c

@@ -675,7 +675,7 @@ static void gfx_v9_4_3_select_me_pipe_q(struct amdgpu_device *adev,
 static enum amdgpu_gfx_partition
 gfx_v9_4_3_query_compute_partition(struct amdgpu_device *adev)
 {
-	enum amdgpu_gfx_partition mode = AMDGPU_UNKNOWN_COMPUTE_PARTITION_MODE;
+	enum amdgpu_gfx_partition mode = adev->gfx.partition_mode;
 
 	if (adev->nbio.funcs->get_compute_partition_mode)
 		mode = adev->nbio.funcs->get_compute_partition_mode(adev);
@@ -689,9 +689,6 @@ static int gfx_v9_4_3_switch_compute_partition(struct amdgpu_device *adev,
 	u32 tmp = 0;
 	int num_xcc_per_partition, i, num_xcc;
 
-	if (mode == adev->gfx.partition_mode)
-		return mode;
-
 	num_xcc = NUM_XCC(adev->gfx.xcc_mask);
 	switch (mode) {
 	case AMDGPU_SPX_PARTITION_MODE:

drivers/gpu/drm/amd/amdkfd/kfd_device.c

@@ -1356,6 +1356,27 @@ unsigned int kfd_get_num_xgmi_sdma_engines(struct kfd_node *node)
 		kfd_get_num_sdma_engines(node);
 }
 
+int kgd2kfd_check_and_lock_kfd(void)
+{
+	mutex_lock(&kfd_processes_mutex);
+	if (!hash_empty(kfd_processes_table) || kfd_is_locked()) {
+		mutex_unlock(&kfd_processes_mutex);
+		return -EBUSY;
+	}
+
+	++kfd_locked;
+	mutex_unlock(&kfd_processes_mutex);
+
+	return 0;
+}
+
+void kgd2kfd_unlock_kfd(void)
+{
+	mutex_lock(&kfd_processes_mutex);
+	--kfd_locked;
+	mutex_unlock(&kfd_processes_mutex);
+}
+
 #if defined(CONFIG_DEBUG_FS)
 
 /* This function will send a package to HIQ to hang the HWS