drivers/xen/gntdev-common.h

Source file repositories/reference/linux-study-clean/drivers/xen/gntdev-common.h

File Facts

System
Linux kernel
Corpus path
drivers/xen/gntdev-common.h
Extension
.h
Size
2535 bytes
Lines
102
Domain
Driver Families
Bucket
drivers/xen
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct gntdev_priv {
	/* Maps with visible offsets in the file descriptor. */
	struct list_head maps;
	/* lock protects maps and freeable_maps. */
	struct mutex lock;

	/* Free instances of struct gntdev_copy_batch. */
	struct gntdev_copy_batch *batch;
	struct mutex batch_lock;

#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
	/* Device for which DMA memory is allocated. */
	struct device *dma_dev;
#endif

#ifdef CONFIG_XEN_GNTDEV_DMABUF
	struct gntdev_dmabuf_priv *dmabuf_priv;
#endif
};

struct gntdev_unmap_notify {
	int flags;
	/* Address relative to the start of the gntdev_grant_map. */
	int addr;
	evtchn_port_t event;
};

struct gntdev_grant_map {
	atomic_t in_use;
	struct mmu_interval_notifier notifier;
	bool notifier_init;
	struct list_head next;
	int index;
	int count;
	int flags;
	refcount_t users;
	struct gntdev_unmap_notify notify;
	struct ioctl_gntdev_grant_ref *grants;
	struct gnttab_map_grant_ref   *map_ops;
	struct gnttab_unmap_grant_ref *unmap_ops;
	struct gnttab_map_grant_ref   *kmap_ops;
	struct gnttab_unmap_grant_ref *kunmap_ops;
	bool *being_removed;
	struct page **pages;
	unsigned long pages_vm_start;

#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
	/*
	 * If dmabuf_vaddr is not NULL then this mapping is backed by DMA
	 * capable memory.
	 */

	struct device *dma_dev;
	/* Flags used to create this DMA buffer: GNTDEV_DMA_FLAG_XXX. */
	int dma_flags;
	void *dma_vaddr;
	dma_addr_t dma_bus_addr;
	/* Needed to avoid allocation in gnttab_dma_free_pages(). */
	xen_pfn_t *frames;
#endif

	/* Number of live grants */
	atomic_t live_grants;
	/* Needed to avoid allocation in __unmap_grant_pages */
	struct gntab_unmap_queue_data unmap_data;
};

struct gntdev_grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count,
					  int dma_flags);

void gntdev_add_map(struct gntdev_priv *priv, struct gntdev_grant_map *add);

void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map);

bool gntdev_test_page_count(unsigned int count);

int gntdev_map_grant_pages(struct gntdev_grant_map *map);

#endif

Annotation

Implementation Notes