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404 lines
12 KiB
404 lines
12 KiB
#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 <uapi/linux/virtio_config.h> |
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/** |
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* virtio_config_ops - operations for configuring a virtio device |
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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 |
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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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* callbacks: array of callbacks, for each virtqueue |
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* include a NULL entry for vqs that do not need a callback |
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* names: array of virtqueue names (mainly for debugging) |
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* include a NULL entry for vqs unused by driver |
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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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* @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 32 feature bits (all we currently 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 gives the final feature bits for the device: it can change |
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* the dev->feature bits if it wants. |
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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 |
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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. |
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*/ |
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typedef void vq_callback_t(struct virtqueue *); |
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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 *, unsigned nvqs, |
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struct virtqueue *vqs[], |
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vq_callback_t *callbacks[], |
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const char *names[]); |
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void (*del_vqs)(struct virtio_device *); |
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u64 (*get_features)(struct virtio_device *vdev); |
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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, int cpu); |
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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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/* Did you forget to fix assumptions on max features? */ |
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if (__builtin_constant_p(fbit)) |
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BUILD_BUG_ON(fbit >= 64); |
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else |
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BUG_ON(fbit >= 64); |
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return vdev->features & BIT_ULL(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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/* Did you forget to fix assumptions on max features? */ |
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if (__builtin_constant_p(fbit)) |
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BUILD_BUG_ON(fbit >= 64); |
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else |
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BUG_ON(fbit >= 64); |
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vdev->features |= BIT_ULL(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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/* Did you forget to fix assumptions on max features? */ |
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if (__builtin_constant_p(fbit)) |
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BUILD_BUG_ON(fbit >= 64); |
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else |
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BUG_ON(fbit >= 64); |
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vdev->features &= ~BIT_ULL(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 |
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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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vq_callback_t *callbacks[] = { c }; |
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const char *names[] = { n }; |
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struct virtqueue *vq; |
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int err = vdev->config->find_vqs(vdev, 1, &vq, callbacks, names); |
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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_device_ready - enable vq use in probe function |
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* @vdev: the 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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BUG_ON(status & VIRTIO_CONFIG_S_DRIVER_OK); |
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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: the cpu no. |
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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, int cpu) |
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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); |
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return 0; |
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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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/* Config space accessors. */ |
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#define virtio_cread(vdev, structname, member, ptr) \ |
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do { \ |
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/* Must match the member's type, and be integer */ \ |
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if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \ |
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(*ptr) = 1; \ |
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\ |
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switch (sizeof(*ptr)) { \ |
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case 1: \ |
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*(ptr) = virtio_cread8(vdev, \ |
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offsetof(structname, member)); \ |
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break; \ |
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case 2: \ |
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*(ptr) = virtio_cread16(vdev, \ |
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offsetof(structname, member)); \ |
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break; \ |
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case 4: \ |
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*(ptr) = virtio_cread32(vdev, \ |
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offsetof(structname, member)); \ |
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break; \ |
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case 8: \ |
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*(ptr) = virtio_cread64(vdev, \ |
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offsetof(structname, member)); \ |
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break; \ |
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default: \ |
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BUG(); \ |
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} \ |
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} while(0) |
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/* Config space accessors. */ |
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#define virtio_cwrite(vdev, structname, member, ptr) \ |
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do { \ |
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/* Must match the member's type, and be integer */ \ |
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if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \ |
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BUG_ON((*ptr) == 1); \ |
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\ |
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switch (sizeof(*ptr)) { \ |
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case 1: \ |
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virtio_cwrite8(vdev, \ |
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offsetof(structname, member), \ |
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*(ptr)); \ |
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break; \ |
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case 2: \ |
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virtio_cwrite16(vdev, \ |
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offsetof(structname, member), \ |
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*(ptr)); \ |
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break; \ |
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case 4: \ |
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virtio_cwrite32(vdev, \ |
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offsetof(structname, member), \ |
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*(ptr)); \ |
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break; \ |
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case 8: \ |
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virtio_cwrite64(vdev, \ |
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offsetof(structname, member), \ |
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*(ptr)); \ |
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break; \ |
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default: \ |
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BUG(); \ |
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} \ |
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} while(0) |
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/* Read @count fields, @bytes each. */ |
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static inline void __virtio_cread_many(struct virtio_device *vdev, |
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unsigned int offset, |
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void *buf, size_t count, size_t bytes) |
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{ |
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u32 old, gen = vdev->config->generation ? |
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vdev->config->generation(vdev) : 0; |
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int i; |
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do { |
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old = gen; |
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for (i = 0; i < count; i++) |
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vdev->config->get(vdev, offset + bytes * i, |
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buf + i * bytes, bytes); |
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gen = vdev->config->generation ? |
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vdev->config->generation(vdev) : 0; |
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} while (gen != old); |
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} |
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static inline void virtio_cread_bytes(struct virtio_device *vdev, |
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unsigned int offset, |
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void *buf, size_t len) |
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{ |
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__virtio_cread_many(vdev, offset, buf, len, 1); |
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} |
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static inline u8 virtio_cread8(struct virtio_device *vdev, unsigned int offset) |
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{ |
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u8 ret; |
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vdev->config->get(vdev, offset, &ret, sizeof(ret)); |
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return ret; |
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} |
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static inline void virtio_cwrite8(struct virtio_device *vdev, |
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unsigned int offset, u8 val) |
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{ |
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vdev->config->set(vdev, offset, &val, sizeof(val)); |
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} |
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static inline u16 virtio_cread16(struct virtio_device *vdev, |
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unsigned int offset) |
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{ |
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u16 ret; |
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vdev->config->get(vdev, offset, &ret, sizeof(ret)); |
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return virtio16_to_cpu(vdev, (__force __virtio16)ret); |
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} |
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static inline void virtio_cwrite16(struct virtio_device *vdev, |
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unsigned int offset, u16 val) |
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{ |
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val = (__force u16)cpu_to_virtio16(vdev, val); |
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vdev->config->set(vdev, offset, &val, sizeof(val)); |
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} |
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static inline u32 virtio_cread32(struct virtio_device *vdev, |
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unsigned int offset) |
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{ |
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u32 ret; |
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vdev->config->get(vdev, offset, &ret, sizeof(ret)); |
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return virtio32_to_cpu(vdev, (__force __virtio32)ret); |
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} |
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static inline void virtio_cwrite32(struct virtio_device *vdev, |
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unsigned int offset, u32 val) |
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{ |
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val = (__force u32)cpu_to_virtio32(vdev, val); |
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vdev->config->set(vdev, offset, &val, sizeof(val)); |
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} |
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static inline u64 virtio_cread64(struct virtio_device *vdev, |
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unsigned int offset) |
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{ |
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u64 ret; |
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__virtio_cread_many(vdev, offset, &ret, 1, sizeof(ret)); |
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return virtio64_to_cpu(vdev, (__force __virtio64)ret); |
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} |
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static inline void virtio_cwrite64(struct virtio_device *vdev, |
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unsigned int offset, u64 val) |
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{ |
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val = (__force u64)cpu_to_virtio64(vdev, val); |
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vdev->config->set(vdev, offset, &val, sizeof(val)); |
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} |
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/* Conditional config space accessors. */ |
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#define virtio_cread_feature(vdev, fbit, structname, member, ptr) \ |
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({ \ |
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int _r = 0; \ |
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if (!virtio_has_feature(vdev, fbit)) \ |
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_r = -ENOENT; \ |
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else \ |
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virtio_cread((vdev), structname, member, ptr); \ |
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_r; \ |
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}) |
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#endif /* _LINUX_VIRTIO_CONFIG_H */
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