[PATCH v9 12/18] drm/amdgpu: integrate SVM into build system and VM fault path

From: Honglei Huang <[email protected]>

Wire up the SVM subsystem:

Kconfig:
- CONFIG_DRM_AMDGPU_SVM option, depends on DEVICE_PRIVATE, selects
  DRM_GPUSVM, HMM_MIRROR, MMU_NOTIFIER, default n

Makefile:
- Build amdgpu_svm.o, amdgpu_svm_attr.o, amdgpu_svm_fault.o,
  amdgpu_svm_range.o when CONFIG_DRM_AMDGPU_SVM=y
- KBUILD_EXTRA_SYMBOLS for drm Module.symvers
- clean-svm phony target for development convenience

amdgpu_drv.c:
- Register DRM_IOCTL_DEF_DRV in ioctl table

amdgpu_vm.c:
- Initialize vm->svm = NULL in amdgpu_vm_init
- Call amdgpu_svm_init in amdgpu_vm_make_compute
- Call amdgpu_svm_close + amdgpu_svm_fini in amdgpu_vm_fini
- Route GPU page faults through amdgpu_svm_handle_fault when SVM
  context exists, without falling back to svm_range_restore_pages

Signed-off-by: Honglei Huang <[email protected]>
---
 drivers/gpu/drm/amd/amdgpu/Kconfig      | 10 ++++++++++
 drivers/gpu/drm/amd/amdgpu/Makefile     |  9 +++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c |  2 ++
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c  | 23 +++++++++++++++++++++--
 4 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/Kconfig b/drivers/gpu/drm/amd/amdgpu/Kconfig
index 12e4a41bf1f04..68f519b3479db 100644
--- a/drivers/gpu/drm/amd/amdgpu/Kconfig
+++ b/drivers/gpu/drm/amd/amdgpu/Kconfig
@@ -81,6 +81,16 @@ config DRM_AMDGPU_USERPTR
 	  This option selects CONFIG_HMM and CONFIG_HMM_MIRROR if it
 	  isn't already selected to enabled full userptr support.
 
+config DRM_AMDGPU_SVM
+	bool "Enable AMDGPU SVM support (experimental)"
+	depends on DRM_AMDGPU
+	depends on DEVICE_PRIVATE
+	select DRM_GPUSVM
+	select HMM_MIRROR
+	select MMU_NOTIFIER
+	help
+	  Experimental SVM support based on DRM GPUSVM.
+
 config DRM_AMD_ISP
 	bool "Enable AMD Image Signal Processor IP support"
 	depends on DRM_AMDGPU && ACPI
diff --git a/drivers/gpu/drm/amd/amdgpu/Makefile b/drivers/gpu/drm/amd/amdgpu/Makefile
index ba80542ead9d9..884cdc5c1e4af 100644
--- a/drivers/gpu/drm/amd/amdgpu/Makefile
+++ b/drivers/gpu/drm/amd/amdgpu/Makefile
@@ -322,6 +322,15 @@ amdgpu-$(CONFIG_VGA_SWITCHEROO) += amdgpu_atpx_handler.o
 amdgpu-$(CONFIG_ACPI) += amdgpu_acpi.o
 amdgpu-$(CONFIG_HMM_MIRROR) += amdgpu_hmm.o
 
+# svm support
+amdgpu-$(CONFIG_DRM_AMDGPU_SVM) += amdgpu_svm.o amdgpu_svm_attr.o \
+	amdgpu_svm_fault.o amdgpu_svm_range.o
+
+.PHONY: clean-svm
+clean-svm:
+	rm -f $(obj)/amdgpu_svm.o $(obj)/amdgpu_svm_attr.o $(obj)/amdgpu_svm_fault.o $(obj)/amdgpu_svm_range.o \
+	      $(obj)/.amdgpu_svm.o.cmd $(obj)/.amdgpu_svm_attr.o.cmd $(obj)/.amdgpu_svm_fault.o.cmd $(obj)/.amdgpu_svm_range.o.cmd
+
 include $(FULL_AMD_PATH)/pm/Makefile
 
 amdgpu-y += $(AMD_POWERPLAY_FILES)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index 503bb64c1e55f..46a074caba53a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -51,6 +51,7 @@
 #include "amdgpu_ras.h"
 #include "amdgpu_reset.h"
 #include "amdgpu_sched.h"
+#include "amdgpu_svm.h"
 #include "amdgpu_xgmi.h"
 #include "amdgpu_userq.h"
 #include "amdgpu_userq_fence.h"
@@ -3077,6 +3078,7 @@ const struct drm_ioctl_desc amdgpu_ioctls_kms[] = {
 	DRM_IOCTL_DEF_DRV(AMDGPU_USERQ_WAIT, amdgpu_userq_wait_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(AMDGPU_GEM_LIST_HANDLES, amdgpu_gem_list_handles_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(AMDGPU_PROC_OPTIONS, amdgpu_proc_options_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(AMDGPU_GEM_SVM, amdgpu_gem_svm_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
 };
 
 static const struct drm_driver amdgpu_kms_driver = {
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 7a4d452a0ed9c..e91fa4cb5a16d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -44,6 +44,7 @@
 #include "amdgpu_xgmi.h"
 #include "amdgpu_dma_buf.h"
 #include "amdgpu_res_cursor.h"
+#include "amdgpu_svm.h"
 #include "kfd_svm.h"
 
 /**
@@ -2640,6 +2641,7 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 	int r, i;
 
 	vm->va = RB_ROOT_CACHED;
+	vm->svm = NULL;
 	for (i = 0; i < AMDGPU_MAX_VMHUBS; i++)
 		vm->reserved_vmid[i] = NULL;
 
@@ -2798,6 +2800,10 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 	vm->is_compute_context = true;
 	vm->need_tlb_fence = true;
 
+	r = amdgpu_svm_init(adev, vm);
+	if (r)
+		goto unreserve_bo;
+
 unreserve_bo:
 	amdgpu_bo_unreserve(vm->root.bo);
 	return r;
@@ -2830,6 +2836,9 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 	unsigned long flags;
 	int i;
 
+	amdgpu_svm_close(vm);
+	amdgpu_svm_fini(vm);
+
 	amdgpu_amdkfd_gpuvm_destroy_cb(adev, vm);
 
 	root = amdgpu_bo_ref(vm->root.bo);
@@ -3053,6 +3062,7 @@ bool amdgpu_vm_handle_fault(struct amdgpu_device *adev, u32 pasid,
 {
 	struct amdgpu_vm_update_params params;
 	bool is_compute_context;
+	bool use_amdgpu_svm = false;
 	struct amdgpu_bo *root;
 	uint64_t value, flags;
 	struct amdgpu_vm *vm;
@@ -3064,14 +3074,23 @@ bool amdgpu_vm_handle_fault(struct amdgpu_device *adev, u32 pasid,
 		return false;
 
 	is_compute_context = vm->is_compute_context;
+	use_amdgpu_svm = !!vm->svm;
 
 	if (is_compute_context) {
 		/* Unreserve root since svm_range_restore_pages might try to reserve it. */
 		/* TODO: rework svm_range_restore_pages so that this isn't necessary. */
 		amdgpu_bo_unreserve(root);
 
-		if (!svm_range_restore_pages(adev, pasid, vmid,
-					     node_id, addr >> PAGE_SHIFT, ts, write_fault)) {
+		if (use_amdgpu_svm)
+			r = amdgpu_svm_handle_fault(adev, pasid,
+						    addr >> PAGE_SHIFT, ts,
+						    write_fault);
+		else
+			r = svm_range_restore_pages(adev, pasid, vmid, node_id,
+						    addr >> PAGE_SHIFT, ts,
+						    write_fault);
+
+		if (!r) {
 			amdgpu_bo_unref(&root);
 			return true;
 		}
-- 
2.53.0