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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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bee8c7c24b
This patch introduces map operations for virtio device. Virtio used to use DMA API which is not necessarily the case since some devices doesn't do DMA. Instead of using tricks and abusing DMA API, let's simply abstract the current mapping logic into a virtio specific mapping operations. For the device or transport that doesn't do DMA, they can implement their own mapping logic without the need to trick DMA core. In this case the mapping metadata is opaque to the virtio core that will be passed back to the transport or device specific map operations. For other devices, DMA API will still be used, so map token will still be the dma device to minimize the changeset and performance impact. The mapping operations are abstracted as a independent structure instead of reusing virtio_config_ops. This allows the transport can simply reuse the structure for lower layers like vDPA. A set of new mapping helpers were introduced for the device that want to do mapping by themselves. Signed-off-by: Jason Wang <jasowang@redhat.com> Message-Id: <20250821064641.5025-7-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Lei Yang <leiyang@redhat.com> Reviewed-by: Eugenio Pérez <eperezma@redhat.com>
700 lines
21 KiB
C
700 lines
21 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_VIRTIO_CONFIG_H
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#define _LINUX_VIRTIO_CONFIG_H
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#include <linux/err.h>
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#include <linux/bug.h>
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#include <linux/virtio.h>
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#include <linux/virtio_byteorder.h>
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#include <linux/compiler_types.h>
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#include <uapi/linux/virtio_config.h>
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struct irq_affinity;
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struct virtio_shm_region {
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u64 addr;
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u64 len;
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};
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typedef void vq_callback_t(struct virtqueue *);
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/**
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* struct virtqueue_info - Info for a virtqueue passed to find_vqs().
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* @name: virtqueue description. Used mainly for debugging, NULL for
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* a virtqueue unused by the driver.
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* @callback: A callback to invoke on a used buffer notification.
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* NULL for a virtqueue that does not need a callback.
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* @ctx: A flag to indicate to maintain an extra context per virtqueue.
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*/
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struct virtqueue_info {
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const char *name;
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vq_callback_t *callback;
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bool ctx;
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};
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/**
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* struct virtio_config_ops - operations for configuring a virtio device
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* Note: Do not assume that a transport implements all of the operations
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* getting/setting a value as a simple read/write! Generally speaking,
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* any of @get/@set, @get_status/@set_status, or @get_features/
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* @finalize_features are NOT safe to be called from an atomic
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* context.
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* @get: read the value of a configuration field
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* vdev: the virtio_device
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* offset: the offset of the configuration field
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* buf: the buffer to write the field value into.
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* len: the length of the buffer
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* @set: write the value of a configuration field
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* vdev: the virtio_device
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* offset: the offset of the configuration field
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* buf: the buffer to read the field value from.
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* len: the length of the buffer
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* @generation: config generation counter (optional)
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* vdev: the virtio_device
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* Returns the config generation counter
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* @get_status: read the status byte
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* vdev: the virtio_device
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* Returns the status byte
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* @set_status: write the status byte
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* vdev: the virtio_device
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* status: the new status byte
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* @reset: reset the device
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* vdev: the virtio device
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* After this, status and feature negotiation must be done again
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* Device must not be reset from its vq/config callbacks, or in
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* parallel with being added/removed.
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* @find_vqs: find virtqueues and instantiate them.
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* vdev: the virtio_device
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* nvqs: the number of virtqueues to find
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* vqs: on success, includes new virtqueues
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* vqs_info: array of virtqueue info structures
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* Returns 0 on success or error status
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* @del_vqs: free virtqueues found by find_vqs().
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* @synchronize_cbs: synchronize with the virtqueue callbacks (optional)
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* The function guarantees that all memory operations on the
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* queue before it are visible to the vring_interrupt() that is
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* called after it.
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* vdev: the virtio_device
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* @get_features: get the array of feature bits for this device.
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* vdev: the virtio_device
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* Returns the first 64 feature bits.
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* @get_extended_features:
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* vdev: the virtio_device
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* Returns the first VIRTIO_FEATURES_MAX feature bits (all we currently
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* need).
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* @finalize_features: confirm what device features we'll be using.
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* vdev: the virtio_device
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* This sends the driver feature bits to the device: it can change
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* the dev->feature bits if it wants.
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* Note that despite the name this can be called any number of
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* times.
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* Returns 0 on success or error status
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* @bus_name: return the bus name associated with the device (optional)
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* vdev: the virtio_device
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* This returns a pointer to the bus name a la pci_name from which
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* the caller can then copy.
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* @set_vq_affinity: set the affinity for a virtqueue (optional).
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* @get_vq_affinity: get the affinity for a virtqueue (optional).
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* @get_shm_region: get a shared memory region based on the index.
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* @disable_vq_and_reset: reset a queue individually (optional).
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* vq: the virtqueue
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* Returns 0 on success or error status
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* disable_vq_and_reset will guarantee that the callbacks are disabled and
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* synchronized.
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* Except for the callback, the caller should guarantee that the vring is
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* not accessed by any functions of virtqueue.
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* @enable_vq_after_reset: enable a reset queue
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* vq: the virtqueue
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* Returns 0 on success or error status
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* If disable_vq_and_reset is set, then enable_vq_after_reset must also be
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* set.
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*/
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struct virtio_config_ops {
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void (*get)(struct virtio_device *vdev, unsigned offset,
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void *buf, unsigned len);
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void (*set)(struct virtio_device *vdev, unsigned offset,
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const void *buf, unsigned len);
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u32 (*generation)(struct virtio_device *vdev);
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u8 (*get_status)(struct virtio_device *vdev);
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void (*set_status)(struct virtio_device *vdev, u8 status);
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void (*reset)(struct virtio_device *vdev);
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int (*find_vqs)(struct virtio_device *vdev, unsigned int nvqs,
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struct virtqueue *vqs[],
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struct virtqueue_info vqs_info[],
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struct irq_affinity *desc);
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void (*del_vqs)(struct virtio_device *);
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void (*synchronize_cbs)(struct virtio_device *);
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u64 (*get_features)(struct virtio_device *vdev);
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void (*get_extended_features)(struct virtio_device *vdev,
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u64 *features);
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int (*finalize_features)(struct virtio_device *vdev);
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const char *(*bus_name)(struct virtio_device *vdev);
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int (*set_vq_affinity)(struct virtqueue *vq,
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const struct cpumask *cpu_mask);
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const struct cpumask *(*get_vq_affinity)(struct virtio_device *vdev,
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int index);
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bool (*get_shm_region)(struct virtio_device *vdev,
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struct virtio_shm_region *region, u8 id);
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int (*disable_vq_and_reset)(struct virtqueue *vq);
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int (*enable_vq_after_reset)(struct virtqueue *vq);
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};
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/**
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* struct virtio_map_ops - operations for mapping buffer for a virtio device
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* Note: For transport that has its own mapping logic it must
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* implements all of the operations
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* @map_page: map a buffer to the device
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* map: metadata for performing mapping
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* page: the page that will be mapped by the device
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* offset: the offset in the page for a buffer
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* size: the buffer size
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* dir: mapping direction
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* attrs: mapping attributes
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* Returns: the mapped address
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* @unmap_page: unmap a buffer from the device
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* map: device specific mapping map
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* map_handle: the mapped address
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* size: the buffer size
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* dir: mapping direction
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* attrs: unmapping attributes
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* @sync_single_for_cpu: sync a single buffer from device to cpu
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* map: metadata for performing mapping
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* map_handle: the mapping address to sync
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* size: the size of the buffer
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* dir: synchronization direction
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* @sync_single_for_device: sync a single buffer from cpu to device
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* map: metadata for performing mapping
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* map_handle: the mapping address to sync
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* size: the size of the buffer
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* dir: synchronization direction
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* @alloc: alloc a coherent buffer mapping
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* map: metadata for performing mapping
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* size: the size of the buffer
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* map_handle: the mapping address to sync
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* gfp: allocation flag (GFP_XXX)
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* Returns: virtual address of the allocated buffer
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* @free: free a coherent buffer mapping
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* map: metadata for performing mapping
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* size: the size of the buffer
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* vaddr: virtual address of the buffer
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* map_handle: the mapping address to sync
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* attrs: unmapping attributes
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* @need_sync: if the buffer needs synchronization
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* map: metadata for performing mapping
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* map_handle: the mapped address
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* Returns: whether the buffer needs synchronization
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* @mapping_error: if the mapping address is error
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* map: metadata for performing mapping
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* map_handle: the mapped address
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* @max_mapping_size: get the maximum buffer size that can be mapped
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* map: metadata for performing mapping
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* Returns: the maximum buffer size that can be mapped
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*/
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struct virtio_map_ops {
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dma_addr_t (*map_page)(union virtio_map map, struct page *page,
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unsigned long offset, size_t size,
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enum dma_data_direction dir, unsigned long attrs);
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void (*unmap_page)(union virtio_map map, dma_addr_t map_handle,
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size_t size, enum dma_data_direction dir,
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unsigned long attrs);
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void (*sync_single_for_cpu)(union virtio_map map, dma_addr_t map_handle,
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size_t size, enum dma_data_direction dir);
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void (*sync_single_for_device)(union virtio_map map,
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dma_addr_t map_handle, size_t size,
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enum dma_data_direction dir);
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void *(*alloc)(union virtio_map map, size_t size,
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dma_addr_t *map_handle, gfp_t gfp);
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void (*free)(union virtio_map map, size_t size, void *vaddr,
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dma_addr_t map_handle, unsigned long attrs);
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bool (*need_sync)(union virtio_map map, dma_addr_t map_handle);
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int (*mapping_error)(union virtio_map map, dma_addr_t map_handle);
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size_t (*max_mapping_size)(union virtio_map map);
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};
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/* If driver didn't advertise the feature, it will never appear. */
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void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
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unsigned int fbit);
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/**
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* __virtio_test_bit - helper to test feature bits. For use by transports.
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* Devices should normally use virtio_has_feature,
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* which includes more checks.
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* @vdev: the device
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* @fbit: the feature bit
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*/
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static inline bool __virtio_test_bit(const struct virtio_device *vdev,
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unsigned int fbit)
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{
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return virtio_features_test_bit(vdev->features_array, fbit);
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}
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/**
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* __virtio_set_bit - helper to set feature bits. For use by transports.
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* @vdev: the device
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* @fbit: the feature bit
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*/
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static inline void __virtio_set_bit(struct virtio_device *vdev,
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unsigned int fbit)
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{
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virtio_features_set_bit(vdev->features_array, fbit);
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}
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/**
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* __virtio_clear_bit - helper to clear feature bits. For use by transports.
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* @vdev: the device
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* @fbit: the feature bit
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*/
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static inline void __virtio_clear_bit(struct virtio_device *vdev,
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unsigned int fbit)
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{
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virtio_features_clear_bit(vdev->features_array, fbit);
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}
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/**
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* virtio_has_feature - helper to determine if this device has this feature.
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* @vdev: the device
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* @fbit: the feature bit
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*/
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static inline bool virtio_has_feature(const struct virtio_device *vdev,
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unsigned int fbit)
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{
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if (fbit < VIRTIO_TRANSPORT_F_START)
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virtio_check_driver_offered_feature(vdev, fbit);
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return __virtio_test_bit(vdev, fbit);
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}
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static inline void virtio_get_features(struct virtio_device *vdev,
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u64 *features_out)
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{
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if (vdev->config->get_extended_features) {
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vdev->config->get_extended_features(vdev, features_out);
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return;
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}
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virtio_features_from_u64(features_out,
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vdev->config->get_features(vdev));
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}
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/**
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* virtio_has_dma_quirk - determine whether this device has the DMA quirk
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* @vdev: the device
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*/
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static inline bool virtio_has_dma_quirk(const struct virtio_device *vdev)
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{
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/*
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* Note the reverse polarity of the quirk feature (compared to most
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* other features), this is for compatibility with legacy systems.
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*/
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return !virtio_has_feature(vdev, VIRTIO_F_ACCESS_PLATFORM);
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}
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static inline
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int virtio_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
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struct virtqueue *vqs[],
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struct virtqueue_info vqs_info[],
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struct irq_affinity *desc)
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{
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return vdev->config->find_vqs(vdev, nvqs, vqs, vqs_info, desc);
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}
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static inline
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struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev,
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vq_callback_t *c, const char *n)
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{
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struct virtqueue_info vqs_info[] = {
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{ n, c },
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};
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struct virtqueue *vq;
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int err = virtio_find_vqs(vdev, 1, &vq, vqs_info, NULL);
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if (err < 0)
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return ERR_PTR(err);
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return vq;
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}
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/**
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* virtio_synchronize_cbs - synchronize with virtqueue callbacks
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* @dev: the virtio device
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*/
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static inline
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void virtio_synchronize_cbs(struct virtio_device *dev)
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{
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if (dev->config->synchronize_cbs) {
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dev->config->synchronize_cbs(dev);
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} else {
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/*
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* A best effort fallback to synchronize with
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* interrupts, preemption and softirq disabled
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* regions. See comment above synchronize_rcu().
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*/
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synchronize_rcu();
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}
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}
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/**
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* virtio_device_ready - enable vq use in probe function
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* @dev: the virtio device
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*
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* Driver must call this to use vqs in the probe function.
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*
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* Note: vqs are enabled automatically after probe returns.
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*/
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static inline
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void virtio_device_ready(struct virtio_device *dev)
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{
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unsigned status = dev->config->get_status(dev);
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WARN_ON(status & VIRTIO_CONFIG_S_DRIVER_OK);
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#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
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/*
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* The virtio_synchronize_cbs() makes sure vring_interrupt()
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* will see the driver specific setup if it sees vq->broken
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* as false (even if the notifications come before DRIVER_OK).
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*/
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virtio_synchronize_cbs(dev);
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__virtio_unbreak_device(dev);
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#endif
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/*
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* The transport should ensure the visibility of vq->broken
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* before setting DRIVER_OK. See the comments for the transport
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* specific set_status() method.
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*
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* A well behaved device will only notify a virtqueue after
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* DRIVER_OK, this means the device should "see" the coherenct
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* memory write that set vq->broken as false which is done by
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* the driver when it sees DRIVER_OK, then the following
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* driver's vring_interrupt() will see vq->broken as false so
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* we won't lose any notification.
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*/
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dev->config->set_status(dev, status | VIRTIO_CONFIG_S_DRIVER_OK);
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}
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static inline
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const char *virtio_bus_name(struct virtio_device *vdev)
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{
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if (!vdev->config->bus_name)
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return "virtio";
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return vdev->config->bus_name(vdev);
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}
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/**
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* virtqueue_set_affinity - setting affinity for a virtqueue
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* @vq: the virtqueue
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* @cpu_mask: the cpu mask
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*
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* Pay attention the function are best-effort: the affinity hint may not be set
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* due to config support, irq type and sharing.
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*
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*/
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static inline
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int virtqueue_set_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask)
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{
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struct virtio_device *vdev = vq->vdev;
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if (vdev->config->set_vq_affinity)
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return vdev->config->set_vq_affinity(vq, cpu_mask);
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return 0;
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}
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static inline
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bool virtio_get_shm_region(struct virtio_device *vdev,
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struct virtio_shm_region *region_out, u8 id)
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{
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if (!vdev->config->get_shm_region)
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return false;
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return vdev->config->get_shm_region(vdev, region_out, id);
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}
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static inline bool virtio_is_little_endian(struct virtio_device *vdev)
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{
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return virtio_has_feature(vdev, VIRTIO_F_VERSION_1) ||
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virtio_legacy_is_little_endian();
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}
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/* Memory accessors */
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static inline u16 virtio16_to_cpu(struct virtio_device *vdev, __virtio16 val)
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{
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return __virtio16_to_cpu(virtio_is_little_endian(vdev), val);
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}
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static inline __virtio16 cpu_to_virtio16(struct virtio_device *vdev, u16 val)
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{
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return __cpu_to_virtio16(virtio_is_little_endian(vdev), val);
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}
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static inline u32 virtio32_to_cpu(struct virtio_device *vdev, __virtio32 val)
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{
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return __virtio32_to_cpu(virtio_is_little_endian(vdev), val);
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}
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static inline __virtio32 cpu_to_virtio32(struct virtio_device *vdev, u32 val)
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{
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return __cpu_to_virtio32(virtio_is_little_endian(vdev), val);
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}
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static inline u64 virtio64_to_cpu(struct virtio_device *vdev, __virtio64 val)
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{
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return __virtio64_to_cpu(virtio_is_little_endian(vdev), val);
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}
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static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val)
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{
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return __cpu_to_virtio64(virtio_is_little_endian(vdev), val);
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}
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#define virtio_to_cpu(vdev, x) \
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_Generic((x), \
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__u8: (x), \
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__virtio16: virtio16_to_cpu((vdev), (x)), \
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__virtio32: virtio32_to_cpu((vdev), (x)), \
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__virtio64: virtio64_to_cpu((vdev), (x)) \
|
|
)
|
|
|
|
#define cpu_to_virtio(vdev, x, m) \
|
|
_Generic((m), \
|
|
__u8: (x), \
|
|
__virtio16: cpu_to_virtio16((vdev), (x)), \
|
|
__virtio32: cpu_to_virtio32((vdev), (x)), \
|
|
__virtio64: cpu_to_virtio64((vdev), (x)) \
|
|
)
|
|
|
|
#define __virtio_native_type(structname, member) \
|
|
typeof(virtio_to_cpu(NULL, ((structname*)0)->member))
|
|
|
|
/* Config space accessors. */
|
|
#define virtio_cread(vdev, structname, member, ptr) \
|
|
do { \
|
|
typeof(((structname*)0)->member) virtio_cread_v; \
|
|
\
|
|
might_sleep(); \
|
|
/* Sanity check: must match the member's type */ \
|
|
typecheck(typeof(virtio_to_cpu((vdev), virtio_cread_v)), *(ptr)); \
|
|
\
|
|
switch (sizeof(virtio_cread_v)) { \
|
|
case 1: \
|
|
case 2: \
|
|
case 4: \
|
|
vdev->config->get((vdev), \
|
|
offsetof(structname, member), \
|
|
&virtio_cread_v, \
|
|
sizeof(virtio_cread_v)); \
|
|
break; \
|
|
default: \
|
|
__virtio_cread_many((vdev), \
|
|
offsetof(structname, member), \
|
|
&virtio_cread_v, \
|
|
1, \
|
|
sizeof(virtio_cread_v)); \
|
|
break; \
|
|
} \
|
|
*(ptr) = virtio_to_cpu(vdev, virtio_cread_v); \
|
|
} while(0)
|
|
|
|
/* Config space accessors. */
|
|
#define virtio_cwrite(vdev, structname, member, ptr) \
|
|
do { \
|
|
typeof(((structname*)0)->member) virtio_cwrite_v = \
|
|
cpu_to_virtio(vdev, *(ptr), ((structname*)0)->member); \
|
|
\
|
|
might_sleep(); \
|
|
/* Sanity check: must match the member's type */ \
|
|
typecheck(typeof(virtio_to_cpu((vdev), virtio_cwrite_v)), *(ptr)); \
|
|
\
|
|
vdev->config->set((vdev), offsetof(structname, member), \
|
|
&virtio_cwrite_v, \
|
|
sizeof(virtio_cwrite_v)); \
|
|
} while(0)
|
|
|
|
/*
|
|
* Nothing virtio-specific about these, but let's worry about generalizing
|
|
* these later.
|
|
*/
|
|
#define virtio_le_to_cpu(x) \
|
|
_Generic((x), \
|
|
__u8: (u8)(x), \
|
|
__le16: (u16)le16_to_cpu(x), \
|
|
__le32: (u32)le32_to_cpu(x), \
|
|
__le64: (u64)le64_to_cpu(x) \
|
|
)
|
|
|
|
#define virtio_cpu_to_le(x, m) \
|
|
_Generic((m), \
|
|
__u8: (x), \
|
|
__le16: cpu_to_le16(x), \
|
|
__le32: cpu_to_le32(x), \
|
|
__le64: cpu_to_le64(x) \
|
|
)
|
|
|
|
/* LE (e.g. modern) Config space accessors. */
|
|
#define virtio_cread_le(vdev, structname, member, ptr) \
|
|
do { \
|
|
typeof(((structname*)0)->member) virtio_cread_v; \
|
|
\
|
|
might_sleep(); \
|
|
/* Sanity check: must match the member's type */ \
|
|
typecheck(typeof(virtio_le_to_cpu(virtio_cread_v)), *(ptr)); \
|
|
\
|
|
switch (sizeof(virtio_cread_v)) { \
|
|
case 1: \
|
|
case 2: \
|
|
case 4: \
|
|
vdev->config->get((vdev), \
|
|
offsetof(structname, member), \
|
|
&virtio_cread_v, \
|
|
sizeof(virtio_cread_v)); \
|
|
break; \
|
|
default: \
|
|
__virtio_cread_many((vdev), \
|
|
offsetof(structname, member), \
|
|
&virtio_cread_v, \
|
|
1, \
|
|
sizeof(virtio_cread_v)); \
|
|
break; \
|
|
} \
|
|
*(ptr) = virtio_le_to_cpu(virtio_cread_v); \
|
|
} while(0)
|
|
|
|
#define virtio_cwrite_le(vdev, structname, member, ptr) \
|
|
do { \
|
|
typeof(((structname*)0)->member) virtio_cwrite_v = \
|
|
virtio_cpu_to_le(*(ptr), ((structname*)0)->member); \
|
|
\
|
|
might_sleep(); \
|
|
/* Sanity check: must match the member's type */ \
|
|
typecheck(typeof(virtio_le_to_cpu(virtio_cwrite_v)), *(ptr)); \
|
|
\
|
|
vdev->config->set((vdev), offsetof(structname, member), \
|
|
&virtio_cwrite_v, \
|
|
sizeof(virtio_cwrite_v)); \
|
|
} while(0)
|
|
|
|
|
|
/* Read @count fields, @bytes each. */
|
|
static inline void __virtio_cread_many(struct virtio_device *vdev,
|
|
unsigned int offset,
|
|
void *buf, size_t count, size_t bytes)
|
|
{
|
|
u32 old, gen = vdev->config->generation ?
|
|
vdev->config->generation(vdev) : 0;
|
|
int i;
|
|
|
|
might_sleep();
|
|
do {
|
|
old = gen;
|
|
|
|
for (i = 0; i < count; i++)
|
|
vdev->config->get(vdev, offset + bytes * i,
|
|
buf + i * bytes, bytes);
|
|
|
|
gen = vdev->config->generation ?
|
|
vdev->config->generation(vdev) : 0;
|
|
} while (gen != old);
|
|
}
|
|
|
|
static inline void virtio_cread_bytes(struct virtio_device *vdev,
|
|
unsigned int offset,
|
|
void *buf, size_t len)
|
|
{
|
|
__virtio_cread_many(vdev, offset, buf, len, 1);
|
|
}
|
|
|
|
static inline u8 virtio_cread8(struct virtio_device *vdev, unsigned int offset)
|
|
{
|
|
u8 ret;
|
|
|
|
might_sleep();
|
|
vdev->config->get(vdev, offset, &ret, sizeof(ret));
|
|
return ret;
|
|
}
|
|
|
|
static inline void virtio_cwrite8(struct virtio_device *vdev,
|
|
unsigned int offset, u8 val)
|
|
{
|
|
might_sleep();
|
|
vdev->config->set(vdev, offset, &val, sizeof(val));
|
|
}
|
|
|
|
static inline u16 virtio_cread16(struct virtio_device *vdev,
|
|
unsigned int offset)
|
|
{
|
|
__virtio16 ret;
|
|
|
|
might_sleep();
|
|
vdev->config->get(vdev, offset, &ret, sizeof(ret));
|
|
return virtio16_to_cpu(vdev, ret);
|
|
}
|
|
|
|
static inline void virtio_cwrite16(struct virtio_device *vdev,
|
|
unsigned int offset, u16 val)
|
|
{
|
|
__virtio16 v;
|
|
|
|
might_sleep();
|
|
v = cpu_to_virtio16(vdev, val);
|
|
vdev->config->set(vdev, offset, &v, sizeof(v));
|
|
}
|
|
|
|
static inline u32 virtio_cread32(struct virtio_device *vdev,
|
|
unsigned int offset)
|
|
{
|
|
__virtio32 ret;
|
|
|
|
might_sleep();
|
|
vdev->config->get(vdev, offset, &ret, sizeof(ret));
|
|
return virtio32_to_cpu(vdev, ret);
|
|
}
|
|
|
|
static inline void virtio_cwrite32(struct virtio_device *vdev,
|
|
unsigned int offset, u32 val)
|
|
{
|
|
__virtio32 v;
|
|
|
|
might_sleep();
|
|
v = cpu_to_virtio32(vdev, val);
|
|
vdev->config->set(vdev, offset, &v, sizeof(v));
|
|
}
|
|
|
|
static inline u64 virtio_cread64(struct virtio_device *vdev,
|
|
unsigned int offset)
|
|
{
|
|
__virtio64 ret;
|
|
|
|
__virtio_cread_many(vdev, offset, &ret, 1, sizeof(ret));
|
|
return virtio64_to_cpu(vdev, ret);
|
|
}
|
|
|
|
static inline void virtio_cwrite64(struct virtio_device *vdev,
|
|
unsigned int offset, u64 val)
|
|
{
|
|
__virtio64 v;
|
|
|
|
might_sleep();
|
|
v = cpu_to_virtio64(vdev, val);
|
|
vdev->config->set(vdev, offset, &v, sizeof(v));
|
|
}
|
|
|
|
/* Conditional config space accessors. */
|
|
#define virtio_cread_feature(vdev, fbit, structname, member, ptr) \
|
|
({ \
|
|
int _r = 0; \
|
|
if (!virtio_has_feature(vdev, fbit)) \
|
|
_r = -ENOENT; \
|
|
else \
|
|
virtio_cread((vdev), structname, member, ptr); \
|
|
_r; \
|
|
})
|
|
|
|
/* Conditional config space accessors. */
|
|
#define virtio_cread_le_feature(vdev, fbit, structname, member, ptr) \
|
|
({ \
|
|
int _r = 0; \
|
|
if (!virtio_has_feature(vdev, fbit)) \
|
|
_r = -ENOENT; \
|
|
else \
|
|
virtio_cread_le((vdev), structname, member, ptr); \
|
|
_r; \
|
|
})
|
|
|
|
#endif /* _LINUX_VIRTIO_CONFIG_H */
|