drm/amdkfd: register HMM device private zone

Register vram memory as MEMORY_DEVICE_PRIVATE type resource, to
allocate vram backing pages for page migration.
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/Kconfig

@@ -8,6 +8,8 @@ config HSA_AMD
 	depends on DRM_AMDGPU && (X86_64 || ARM64 || PPC64)
 	imply AMD_IOMMU_V2 if X86_64
 	select HMM_MIRROR
+	select ZONE_DEVICE
+	select DEVICE_PRIVATE
 	select MMU_NOTIFIER
 	select DRM_AMDGPU_USERPTR
 	help

drivers/gpu/drm/amd/amdkfd/Makefile

@@ -55,7 +55,8 @@ AMDKFD_FILES	:= $(AMDKFD_PATH)/kfd_module.o \
 		$(AMDKFD_PATH)/kfd_dbgmgr.o \
 		$(AMDKFD_PATH)/kfd_smi_events.o \
 		$(AMDKFD_PATH)/kfd_crat.o \
-		$(AMDKFD_PATH)/kfd_svm.o
+		$(AMDKFD_PATH)/kfd_svm.o \
+		$(AMDKFD_PATH)/kfd_migrate.o
 
 ifneq ($(CONFIG_AMD_IOMMU_V2),)
 AMDKFD_FILES += $(AMDKFD_PATH)/kfd_iommu.o

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

@@ -30,6 +30,7 @@
 #include "kfd_iommu.h"
 #include "amdgpu_amdkfd.h"
 #include "kfd_smi_events.h"
+#include "kfd_migrate.h"
 
 #define MQD_SIZE_ALIGNED 768
 
@@ -814,6 +815,8 @@ bool kgd2kfd_device_init(struct kfd_dev *kfd,
 
 	kfd_cwsr_init(kfd);
 
+	svm_migrate_init((struct amdgpu_device *)kfd->kgd);
+
 	if (kfd_resume(kfd))
 		goto kfd_resume_error;
 
@@ -862,6 +865,7 @@ void kgd2kfd_device_exit(struct kfd_dev *kfd)
 {
 	if (kfd->init_complete) {
 		kgd2kfd_suspend(kfd, false);
+		svm_migrate_fini((struct amdgpu_device *)kfd->kgd);
 		device_queue_manager_uninit(kfd->dqm);
 		kfd_interrupt_exit(kfd);
 		kfd_topology_remove_device(kfd);

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

+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Copyright 2020-2021 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 <linux/types.h>
+#include <linux/hmm.h>
+#include <linux/dma-direction.h>
+#include <linux/dma-mapping.h>
+#include "amdgpu_sync.h"
+#include "amdgpu_object.h"
+#include "amdgpu_vm.h"
+#include "amdgpu_mn.h"
+#include "kfd_priv.h"
+#include "kfd_svm.h"
+#include "kfd_migrate.h"
+
+static void svm_migrate_page_free(struct page *page)
+{
+}
+
+/**
+ * svm_migrate_to_ram - CPU page fault handler
+ * @vmf: CPU vm fault vma, address
+ *
+ * Context: vm fault handler, mm->mmap_sem is taken
+ *
+ * Return:
+ * 0 - OK
+ * VM_FAULT_SIGBUS - notice application to have SIGBUS page fault
+ */
+static vm_fault_t svm_migrate_to_ram(struct vm_fault *vmf)
+{
+	return VM_FAULT_SIGBUS;
+}
+
+static const struct dev_pagemap_ops svm_migrate_pgmap_ops = {
+	.page_free		= svm_migrate_page_free,
+	.migrate_to_ram		= svm_migrate_to_ram,
+};
+
+int svm_migrate_init(struct amdgpu_device *adev)
+{
+	struct kfd_dev *kfddev = adev->kfd.dev;
+	struct dev_pagemap *pgmap;
+	struct resource *res;
+	unsigned long size;
+	void *r;
+
+	/* Page migration works on Vega10 or newer */
+	if (kfddev->device_info->asic_family < CHIP_VEGA10)
+		return -EINVAL;
+
+	pgmap = &kfddev->pgmap;
+	memset(pgmap, 0, sizeof(*pgmap));
+
+	/* TODO: register all vram to HMM for now.
+	 * should remove reserved size
+	 */
+	size = ALIGN(adev->gmc.real_vram_size, 2ULL << 20);
+	res = devm_request_free_mem_region(adev->dev, &iomem_resource, size);
+	if (IS_ERR(res))
+		return -ENOMEM;
+
+	pgmap->type = MEMORY_DEVICE_PRIVATE;
+	pgmap->nr_range = 1;
+	pgmap->range.start = res->start;
+	pgmap->range.end = res->end;
+	pgmap->ops = &svm_migrate_pgmap_ops;
+	pgmap->owner = adev;
+	pgmap->flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE;
+	r = devm_memremap_pages(adev->dev, pgmap);
+	if (IS_ERR(r)) {
+		pr_err("failed to register HMM device memory\n");
+		return PTR_ERR(r);
+	}
+
+	pr_info("HMM registered %ldMB device memory\n", size >> 20);
+
+	return 0;
+}
+
+void svm_migrate_fini(struct amdgpu_device *adev)
+{
+	memunmap_pages(&adev->kfd.dev->pgmap);
+}

drivers/gpu/drm/amd/amdkfd/kfd_migrate.h

+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+/*
+ * Copyright 2020-2021 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.
+ *
+ */
+
+#ifndef KFD_MIGRATE_H_
+#define KFD_MIGRATE_H_
+
+#include <linux/rwsem.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/sched/mm.h>
+#include <linux/hmm.h>
+#include "kfd_priv.h"
+#include "kfd_svm.h"
+
+#if defined(CONFIG_DEVICE_PRIVATE)
+int svm_migrate_init(struct amdgpu_device *adev);
+void svm_migrate_fini(struct amdgpu_device *adev);
+
+#else
+static inline int svm_migrate_init(struct amdgpu_device *adev)
+{
+	DRM_WARN_ONCE("DEVICE_PRIVATE kernel config option is not enabled, "
+		      "add CONFIG_DEVICE_PRIVATE=y in config file to fix\n");
+	return -ENODEV;
+}
+static inline void svm_migrate_fini(struct amdgpu_device *adev) {}
+#endif
+#endif /* KFD_MIGRATE_H_ */

drivers/gpu/drm/amd/amdkfd/kfd_priv.h

@@ -322,6 +322,9 @@ struct kfd_dev {
 	unsigned int max_doorbell_slices;
 
 	int noretry;
+
+	/* HMM page migration MEMORY_DEVICE_PRIVATE mapping */
+	struct dev_pagemap pgmap;
 };
 
 enum kfd_mempool {