gpu/nouveau/svm: have reserved vma comes as a special mmap of device file

Enforce the reserved area to be the result of mmap on the device file.

Signed-off-by: Jérôme Glisse <jglisse@redhat.com>

4 files changed, 61 insertions, 1 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.h b/drivers/gpu/drm/nouveau/nouveau_drv.h
index abebb91f6764..2d8bed0946bc 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drv.h
+++ b/drivers/gpu/drm/nouveau/nouveau_drv.h
@@ -61,6 +61,7 @@ struct nouveau_channel;
 struct platform_device;
 
 #define DRM_FILE_PAGE_OFFSET (0x100000000ULL >> PAGE_SHIFT)
+#define TTM_FILE_PAGE_OFFSET (0x200000000ULL >> PAGE_SHIFT)
 
 #include "nouveau_fence.h"
 #include "nouveau_bios.h"
diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c
index 183b94511388..7f9e9404a226 100644
--- a/drivers/gpu/drm/nouveau/nouveau_svm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_svm.c
@@ -35,6 +35,8 @@
 #include <linux/sort.h>
 #include <linux/hmm.h>
 
+static const struct vm_operations_struct nvkm_svm_reserved_vma_ops;
+
 struct nouveau_svm {
 	struct nouveau_drm *drm;
 	struct mutex mutex;
@@ -220,6 +222,7 @@ nouveau_svmm_init(struct drm_device *dev, void *data,
 	struct nouveau_vmm *vmm = &cli->vmm;
 	struct nouveau_svmm *svmm;
 	struct drm_nouveau_svm_init *args = data;
+	struct vm_area_struct *vma;
 	int ret = 0;
 
 	/*XXX: Hack to replace per-client GPU address-space with one that
@@ -249,6 +252,15 @@ nouveau_svmm_init(struct drm_device *dev, void *data,
 	/* Enable HMM mirroring of CPU address-space to VMM. */
 	svmm->mm = get_task_mm(current);
 	down_write(&svmm->mm->mmap_sem);
+
+	vma = find_vma(svmm->mm, args->unmanaged_addr);
+	if (vma == NULL || vma->vm_ops != &nvkm_svm_reserved_vma_ops ||
+	    (svmm->unmanaged.limit > vma->vm_end)) {
+		up_write(&svmm->mm->mmap_sem);
+		ret = -EINVAL;
+		goto done;
+	}
+
 	svmm->mirror.ops = &nouveau_svmm;
 	ret = hmm_mirror_register(&svmm->mirror, svmm->mm);
 	up_write(&svmm->mm->mmap_sem);
@@ -769,3 +781,42 @@ nouveau_svm_init(struct nouveau_drm *drm)
 		INIT_LIST_HEAD(&drm->svm->inst);
 	}
 }
+
+static int
+nvkm_svm_reserved_vma_fault(struct vm_fault *vmf)
+{
+	return VM_FAULT_SIGBUS;
+}
+
+static void
+nvkm_svm_reserved_vma_open(struct vm_area_struct *vma)
+{
+}
+
+static void
+nvkm_svm_reserved_vma_close(struct vm_area_struct *vma)
+{
+}
+
+static int
+nvkm_svm_reserved_vma_access(struct vm_area_struct *vma, unsigned long addr,
+			     void *buf, int len, int write)
+{
+	return -EIO;
+}
+
+static const struct vm_operations_struct nvkm_svm_reserved_vma_ops = {
+	.access = nvkm_svm_reserved_vma_access,
+	.close = nvkm_svm_reserved_vma_close,
+	.fault = nvkm_svm_reserved_vma_fault,
+	.open = nvkm_svm_reserved_vma_open,
+};
+
+int
+nvkm_svm_mmap_reserved(struct vm_area_struct *vma)
+{
+	vma->vm_ops = &nvkm_svm_reserved_vma_ops;
+	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP | VM_DONTCOPY;
+
+	return 0;
+}
diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.h b/drivers/gpu/drm/nouveau/nouveau_svm.h
index b43d94b98127..06504dd993bd 100644
--- a/drivers/gpu/drm/nouveau/nouveau_svm.h
+++ b/drivers/gpu/drm/nouveau/nouveau_svm.h
@@ -16,4 +16,8 @@ int nouveau_svmm_init(struct drm_device *, void *, struct drm_file *);
 void nouveau_svmm_fini(struct nouveau_svmm **);
 int nouveau_svmm_join(struct nouveau_svmm *, u64 inst);
 void nouveau_svmm_part(struct nouveau_svmm *, u64 inst);
+
+struct vm_area_struct;
+
+int nvkm_svm_mmap_reserved(struct vm_area_struct *vma);
 #endif
diff --git a/drivers/gpu/drm/nouveau/nouveau_ttm.c b/drivers/gpu/drm/nouveau/nouveau_ttm.c
index 1543c2f8d3d3..152e96a077fc 100644
--- a/drivers/gpu/drm/nouveau/nouveau_ttm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_ttm.c
@@ -26,6 +26,7 @@
 #include "nouveau_gem.h"
 #include "nouveau_mem.h"
 #include "nouveau_ttm.h"
+#include "nouveau_svm.h"
 
 #include <drm/drm_legacy.h>
 
@@ -171,6 +172,9 @@ nouveau_ttm_mmap(struct file *filp, struct vm_area_struct *vma)
 	if (unlikely(vma->vm_pgoff < DRM_FILE_PAGE_OFFSET))
 		return drm_legacy_mmap(filp, vma);
 
+	if (unlikely(vma->vm_pgoff < TTM_FILE_PAGE_OFFSET))
+		return nvkm_svm_mmap_reserved(vma);
+
 	return ttm_bo_mmap(filp, vma, &drm->ttm.bdev);
 }
 
@@ -239,7 +243,7 @@ nouveau_ttm_init(struct nouveau_drm *drm)
 	ret = ttm_bo_device_init(&drm->ttm.bdev,
 				  &nouveau_bo_driver,
 				  dev->anon_inode->i_mapping,
-				  DRM_FILE_PAGE_OFFSET,
+				  TTM_FILE_PAGE_OFFSET,
 				  drm->client.mmu.dmabits <= 32 ? true : false);
 	if (ret) {
 		NV_ERROR(drm, "error initialising bo driver, %d\n", ret);