drm/nouveau/compote: memory object mmap support

Allow mmap of compote device file to access memory objects. Each
memory objects is given a unique range inside the compote device
file.

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

4 files changed, 133 insertions, 2 deletions

diff --git a/drivers/gpu/drm/nouveau/compote/compote-driver.c b/drivers/gpu/drm/nouveau/compote/compote-driver.c
index 6e05ffc351b3..62b4edd1ca7e 100644
--- a/drivers/gpu/drm/nouveau/compote/compote-driver.c
+++ b/drivers/gpu/drm/nouveau/compote/compote-driver.c
@@ -166,6 +166,31 @@ static int compote_close(struct inode *inode, struct file *file)
 	return 0;
 }
 
+static ssize_t compote_read(struct file *filp,
+			    char __user *buf,
+			    size_t count,
+			    loff_t *ppos)
+{
+	return -EINVAL;
+}
+
+static int compote_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct compote_file *cfile = file->private_data;
+
+	if (cfile == NULL)
+		return -EINVAL;
+	return compote_mo_mmap(cfile, vma, file);
+}
+
+static ssize_t compote_write(struct file *filp,
+			     const char __user *buf,
+			     size_t count,
+			     loff_t *ppos)
+{
+	return -EINVAL;
+}
+
 static long compote_ioctl(struct file *file,
 			  unsigned int cmd,
 			  unsigned long arg)
@@ -200,6 +225,9 @@ static long compote_ioctl(struct file *file,
 
 static const struct file_operations compote_fops = {
 	.open		= compote_open,
+	.read		= compote_read,
+	.mmap		= compote_mmap,
+	.write		= compote_write,
 	.release	= compote_close,
 	.unlocked_ioctl	= compote_ioctl,
 	.owner		= THIS_MODULE,
diff --git a/drivers/gpu/drm/nouveau/compote/compote-memory.c b/drivers/gpu/drm/nouveau/compote/compote-memory.c
index 55fca9092846..8435ec0a8d03 100644
--- a/drivers/gpu/drm/nouveau/compote/compote-memory.c
+++ b/drivers/gpu/drm/nouveau/compote/compote-memory.c
@@ -33,11 +33,12 @@ static struct compote_mo *compote_file_mo_find(struct compote_file *cfile,
 					       uint64_t foffset)
 {
 	struct ttm_bo_device *bdev = &cfile->cdevice->nvdrm->ttm.bdev;
+	unsigned long pgoffset = foffset >> PAGE_SHIFT;
 	struct drm_vma_offset_node *node;
 	struct compote_mo *mo = NULL;
 
 	drm_vma_offset_lock_lookup(&bdev->vma_manager);
-	node = drm_vma_offset_lookup_locked(&bdev->vma_manager, foffset, 1);
+	node = drm_vma_offset_lookup_locked(&bdev->vma_manager, pgoffset, 1);
 	if (likely(node)) {
 		struct ttm_buffer_object *bo;
 		struct nouveau_bo *nvbo;
@@ -66,7 +67,6 @@ static int compote_mo_new(struct compote_mo **mop,
 	if (mo == NULL)
 		return -ENOMEM;
 
-
 	align = 0;
 	tile_mode = 0;
 	tile_flags = 0;
@@ -79,6 +79,7 @@ static int compote_mo_new(struct compote_mo **mop,
 	mo->cfile = cfile;
 	mo->nvbo->mo = mo;
 	kref_init(&mo->kref);
+	INIT_LIST_HEAD(&mo->vas);
 	mo->npages = PAGE_ALIGN(nbytes);
 	mo->foffset = drm_vma_node_offset_addr(&mo->nvbo->bo.vma_node);
 
@@ -150,3 +151,88 @@ long compote_ioctl_mem_free(struct compote_file *cfile, void __user *uarg)
 	compote_mo_unref(mo);
 	return 0;
 }
+
+static int compote_vm_fault(struct vm_fault *vmf)
+{
+	struct compote_mo_va *mo_va = vmf->vma->vm_private_data;
+	struct ttm_buffer_object *bo;
+	int ret;
+
+	bo = &mo_va->mo->nvbo->bo;
+	vmf->vma->vm_private_data = bo;
+	ret = mo_va->ttm_vm_ops->fault(vmf);
+	vmf->vma->vm_private_data = mo_va;
+
+	return ret;
+}
+
+static void compote_vm_open(struct vm_area_struct *vma)
+{
+	struct compote_mo_va *mo_va = vma->vm_private_data;
+	struct ttm_buffer_object *bo;
+
+	compote_mo_ref(mo_va->mo);
+
+	bo = &mo_va->mo->nvbo->bo;
+	vma->vm_private_data = bo;
+	mo_va->ttm_vm_ops->open(vma);
+	vma->vm_private_data = mo_va;
+}
+
+static void compote_vm_close(struct vm_area_struct *vma)
+{
+	struct compote_mo_va *mo_va = vma->vm_private_data;
+	struct ttm_buffer_object *bo;
+
+	bo = &mo_va->mo->nvbo->bo;
+	vma->vm_private_data = bo;
+	mo_va->ttm_vm_ops->close(vma);
+
+	list_del_init(&mo_va->list);
+	vma->vm_private_data = NULL;
+	compote_mo_unref(mo_va->mo);
+	kfree(mo_va);
+}
+
+static const struct vm_operations_struct compote_vm_ops = {
+	.fault	= compote_vm_fault,
+	.open	= compote_vm_open,
+	.close	= compote_vm_close
+};
+
+int compote_mo_mmap(struct compote_file *cfile,
+		    struct vm_area_struct *vma,
+		    struct file *file)
+{
+	struct ttm_bo_device *bdev = &cfile->cdevice->nvdrm->ttm.bdev;
+	struct compote_mo_va *mo_va;
+	struct compote_mo *mo;
+	int ret;
+
+	mo = compote_file_mo_find(cfile, vma->vm_pgoff << PAGE_SHIFT);
+	if (mo == NULL)
+		return -EINVAL;
+
+	mo_va = kzalloc(sizeof(*mo_va), GFP_KERNEL);
+	if (mo_va == NULL)
+		return -ENOMEM;
+
+	mo_va->mo = mo;
+	mo_va->start = vma->vm_start;
+	mo_va->end = vma->vm_end;
+	mo_va->pgoffset = vma->vm_pgoff - (mo->foffset >> PAGE_SHIFT);
+
+	ret = ttm_bo_mmap(file, vma, bdev);
+	if (unlikely(ret != 0)) {
+		compote_mo_unref(mo);
+		kfree(mo_va);
+		return ret;
+	}
+
+	list_add_tail(&mo_va->list, &mo->vas);
+	mo_va->ttm_vm_ops = vma->vm_ops;
+	vma->vm_ops = &compote_vm_ops;
+	vma->vm_private_data = mo_va;
+
+	return 0;
+}
diff --git a/drivers/gpu/drm/nouveau/compote/compote.h b/drivers/gpu/drm/nouveau/compote/compote.h
index c0d59960ceef..4d9d2166faf4 100644
--- a/drivers/gpu/drm/nouveau/compote/compote.h
+++ b/drivers/gpu/drm/nouveau/compote/compote.h
@@ -38,15 +38,28 @@ struct compote_file {
 struct compote_mo {
 	struct kref				kref;
 	struct compote_file			*cfile;
+	struct list_head			vas;
 	struct nouveau_bo			*nvbo;
 	uint64_t				npages;
 	uint64_t				foffset;
 };
 
+struct compote_mo_va {
+	uint64_t				start;
+	uint64_t				end;
+	uint64_t				pgoffset;
+	struct compote_mo			*mo;
+	struct list_head			list;
+	const struct vm_operations_struct	*ttm_vm_ops;
+};
+
 long compote_ioctl_mem_alloc(struct compote_file *cfile, void __user *uarg);
 long compote_ioctl_mem_free(struct compote_file *cfile, void __user *uarg);
 
 void compote_mo_ref(struct compote_mo *mo);
 void compote_mo_unref(struct compote_mo *mo);
+int compote_mo_mmap(struct compote_file *cfile,
+		    struct vm_area_struct *vma,
+		    struct file *file);
 
 #endif /* COMPOTE_H */
diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index 3009045cdf46..51762a3764c9 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -1321,6 +1321,10 @@ nouveau_bo_verify_access(struct ttm_buffer_object *bo, struct file *filp)
 {
 	struct nouveau_bo *nvbo = nouveau_bo(bo);
 
+	/* compote do its own check */
+	if (nvbo->mo)
+		return 0;
+
 	return drm_vma_node_verify_access(&nvbo->gem.vma_node,
 					  filp->private_data);
 }