diff options
Diffstat (limited to 'include/virtio.h')
| -rw-r--r-- | include/virtio.h | 707 |
1 files changed, 707 insertions, 0 deletions
diff --git a/include/virtio.h b/include/virtio.h new file mode 100644 index 0000000..654fdf1 --- /dev/null +++ b/include/virtio.h @@ -0,0 +1,707 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi> + * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com> + * + * VirtIO is a virtualization standard for network and disk device drivers + * where just the guest's device driver "knows" it is running in a virtual + * environment, and cooperates with the hypervisor. This enables guests to + * get high performance network and disk operations, and gives most of the + * performance benefits of paravirtualization. In the U-Boot case, the guest + * is U-Boot itself, while the virtual environment are normally QEMU targets + * like ARM, RISC-V and x86. + * + * See http://docs.oasis-open.org/virtio/virtio/v1.0/virtio-v1.0.pdf for + * the VirtIO specification v1.0. + * + * This file is largely based on Linux kernel virtio_*.h files + */ + +#ifndef __VIRTIO_H__ +#define __VIRTIO_H__ + +#define VIRTIO_ID_NET 1 /* virtio net */ +#define VIRTIO_ID_BLOCK 2 /* virtio block */ +#define VIRTIO_ID_MAX_NUM 3 + +#define VIRTIO_NET_DRV_NAME "virtio-net" +#define VIRTIO_BLK_DRV_NAME "virtio-blk" + +/* Status byte for guest to report progress, and synchronize features */ + +/* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */ +#define VIRTIO_CONFIG_S_ACKNOWLEDGE 1 +/* We have found a driver for the device */ +#define VIRTIO_CONFIG_S_DRIVER 2 +/* Driver has used its parts of the config, and is happy */ +#define VIRTIO_CONFIG_S_DRIVER_OK 4 +/* Driver has finished configuring features */ +#define VIRTIO_CONFIG_S_FEATURES_OK 8 +/* Device entered invalid state, driver must reset it */ +#define VIRTIO_CONFIG_S_NEEDS_RESET 0x40 +/* We've given up on this device */ +#define VIRTIO_CONFIG_S_FAILED 0x80 + +/* + * Virtio feature bits VIRTIO_TRANSPORT_F_START through VIRTIO_TRANSPORT_F_END + * are reserved for the transport being used (eg: virtio_ring, virtio_pci etc.), + * the rest are per-device feature bits. + */ +#define VIRTIO_TRANSPORT_F_START 28 +#define VIRTIO_TRANSPORT_F_END 38 + +#ifndef VIRTIO_CONFIG_NO_LEGACY +/* + * Do we get callbacks when the ring is completely used, + * even if we've suppressed them? + */ +#define VIRTIO_F_NOTIFY_ON_EMPTY 24 + +/* Can the device handle any descriptor layout? */ +#define VIRTIO_F_ANY_LAYOUT 27 +#endif /* VIRTIO_CONFIG_NO_LEGACY */ + +/* v1.0 compliant */ +#define VIRTIO_F_VERSION_1 32 + +/* + * If clear - device has the IOMMU bypass quirk feature. + * If set - use platform tools to detect the IOMMU. + * + * Note the reverse polarity (compared to most other features), + * this is for compatibility with legacy systems. + */ +#define VIRTIO_F_IOMMU_PLATFORM 33 + +/* Does the device support Single Root I/O Virtualization? */ +#define VIRTIO_F_SR_IOV 37 + +/** + * virtio scatter-gather struct + * + * @addr: sg buffer address + * @lengh: sg buffer length + */ +struct virtio_sg { + void *addr; + size_t length; +}; + +struct virtqueue; + +/* virtio bus operations */ +struct dm_virtio_ops { + /** + * get_config() - read the value of a configuration field + * + * @vdev: the real virtio device + * @offset: the offset of the configuration field + * @buf: the buffer to write the field value into + * @len: the length of the buffer + * @return 0 if OK, -ve on error + */ + int (*get_config)(struct udevice *vdev, unsigned int offset, + void *buf, unsigned int len); + /** + * set_config() - write the value of a configuration field + * + * @vdev: the real virtio device + * @offset: the offset of the configuration field + * @buf: the buffer to read the field value from + * @len: the length of the buffer + * @return 0 if OK, -ve on error + */ + int (*set_config)(struct udevice *vdev, unsigned int offset, + const void *buf, unsigned int len); + /** + * generation() - config generation counter + * + * @vdev: the real virtio device + * @counter: the returned config generation counter + * @return 0 if OK, -ve on error + */ + int (*generation)(struct udevice *vdev, u32 *counter); + /** + * get_status() - read the status byte + * + * @vdev: the real virtio device + * @status: the returned status byte + * @return 0 if OK, -ve on error + */ + int (*get_status)(struct udevice *vdev, u8 *status); + /** + * set_status() - write the status byte + * + * @vdev: the real virtio device + * @status: the new status byte + * @return 0 if OK, -ve on error + */ + int (*set_status)(struct udevice *vdev, u8 status); + /** + * reset() - reset the device + * + * @vdev: the real virtio device + * @return 0 if OK, -ve on error + */ + int (*reset)(struct udevice *vdev); + /** + * get_features() - get the array of feature bits for this device + * + * @vdev: the real virtio device + * @features: the first 32 feature bits (all we currently need) + * @return 0 if OK, -ve on error + */ + int (*get_features)(struct udevice *vdev, u64 *features); + /** + * set_features() - confirm what device features we'll be using + * + * @vdev: the real virtio device + * @return 0 if OK, -ve on error + */ + int (*set_features)(struct udevice *vdev); + /** + * find_vqs() - find virtqueues and instantiate them + * + * @vdev: the real virtio device + * @nvqs: the number of virtqueues to find + * @vqs: on success, includes new virtqueues + * @return 0 if OK, -ve on error + */ + int (*find_vqs)(struct udevice *vdev, unsigned int nvqs, + struct virtqueue *vqs[]); + /** + * del_vqs() - free virtqueues found by find_vqs() + * + * @vdev: the real virtio device + * @return 0 if OK, -ve on error + */ + int (*del_vqs)(struct udevice *vdev); + /** + * notify() - notify the device to process the queue + * + * @vdev: the real virtio device + * @vq: virtqueue to process + * @return 0 if OK, -ve on error + */ + int (*notify)(struct udevice *vdev, struct virtqueue *vq); +}; + +/* Get access to a virtio bus' operations */ +#define virtio_get_ops(dev) ((struct dm_virtio_ops *)(dev)->driver->ops) + +/** + * virtio uclass per device private data + * + * @vqs: virtualqueue for the virtio device + * @vdev: the real virtio device underneath + * @legacy: is it a legacy device? + * @device: virtio device ID + * @vendor: virtio vendor ID + * @features: negotiated supported features + * @feature_table: an array of feature supported by the driver + * @feature_table_size: number of entries in the feature table array + * @feature_table_legacy: same as feature_table but working in legacy mode + * @feature_table_size_legacy: number of entries in feature table legacy array + */ +struct virtio_dev_priv { + struct list_head vqs; + struct udevice *vdev; + bool legacy; + u32 device; + u32 vendor; + u64 features; + const u32 *feature_table; + u32 feature_table_size; + const u32 *feature_table_legacy; + u32 feature_table_size_legacy; +}; + +/** + * virtio_get_config() - read the value of a configuration field + * + * @vdev: the real virtio device + * @offset: the offset of the configuration field + * @buf: the buffer to write the field value into + * @len: the length of the buffer + * @return 0 if OK, -ve on error + */ +int virtio_get_config(struct udevice *vdev, unsigned int offset, + void *buf, unsigned int len); + +/** + * virtio_set_config() - write the value of a configuration field + * + * @vdev: the real virtio device + * @offset: the offset of the configuration field + * @buf: the buffer to read the field value from + * @len: the length of the buffer + * @return 0 if OK, -ve on error + */ +int virtio_set_config(struct udevice *vdev, unsigned int offset, + void *buf, unsigned int len); + +/** + * virtio_generation() - config generation counter + * + * @vdev: the real virtio device + * @counter: the returned config generation counter + * @return 0 if OK, -ve on error + */ +int virtio_generation(struct udevice *vdev, u32 *counter); + +/** + * virtio_get_status() - read the status byte + * + * @vdev: the real virtio device + * @status: the returned status byte + * @return 0 if OK, -ve on error + */ +int virtio_get_status(struct udevice *vdev, u8 *status); + +/** + * virtio_set_status() - write the status byte + * + * @vdev: the real virtio device + * @status: the new status byte + * @return 0 if OK, -ve on error + */ +int virtio_set_status(struct udevice *vdev, u8 status); + +/** + * virtio_reset() - reset the device + * + * @vdev: the real virtio device + * @return 0 if OK, -ve on error + */ +int virtio_reset(struct udevice *vdev); + +/** + * virtio_get_features() - get the array of feature bits for this device + * + * @vdev: the real virtio device + * @features: the first 32 feature bits (all we currently need) + * @return 0 if OK, -ve on error + */ +int virtio_get_features(struct udevice *vdev, u64 *features); + +/** + * virtio_set_features() - confirm what device features we'll be using + * + * @vdev: the real virtio device + * @return 0 if OK, -ve on error + */ +int virtio_set_features(struct udevice *vdev); + +/** + * virtio_find_vqs() - find virtqueues and instantiate them + * + * @vdev: the real virtio device + * @nvqs: the number of virtqueues to find + * @vqs: on success, includes new virtqueues + * @return 0 if OK, -ve on error + */ +int virtio_find_vqs(struct udevice *vdev, unsigned int nvqs, + struct virtqueue *vqs[]); + +/** + * virtio_del_vqs() - free virtqueues found by find_vqs() + * + * @vdev: the real virtio device + * @return 0 if OK, -ve on error + */ +int virtio_del_vqs(struct udevice *vdev); + +/** + * virtio_notify() - notify the device to process the queue + * + * @vdev: the real virtio device + * @vq: virtqueue to process + * @return 0 if OK, -ve on error + */ +int virtio_notify(struct udevice *vdev, struct virtqueue *vq); + +/** + * virtio_add_status() - helper to set a new status code to the device + * + * @vdev: the real virtio device + * @status: new status code to be added + */ +void virtio_add_status(struct udevice *vdev, u8 status); + +/** + * virtio_finalize_features() - helper to finalize features + * + * @vdev: the real virtio device + * @return 0 if OK, -ve on error + */ +int virtio_finalize_features(struct udevice *vdev); + +/** + * virtio_driver_features_init() - initialize driver supported features + * + * This fills in the virtio device parent per child private data with the given + * information, which contains driver supported features and legacy features. + * + * This API should be called in the virtio device driver's bind method, so that + * later virtio transport uclass driver can utilize the driver supplied features + * to negotiate with the device on the final supported features. + * + * @priv: virtio uclass per device private data + * @feature: an array of feature supported by the driver + * @feature_size: number of entries in the feature table array + * @feature_legacy: same as feature_table but working in legacy mode + * @feature_legacy_size:number of entries in feature table legacy array + */ +void virtio_driver_features_init(struct virtio_dev_priv *priv, + const u32 *feature, + u32 feature_size, + const u32 *feature_legacy, + u32 feature_legacy_size); + +/** + * virtio_init() - helper to enumerate all known virtio devices + * + * @return 0 if OK, -ve on error + */ +int virtio_init(void); + +static inline u16 __virtio16_to_cpu(bool little_endian, __virtio16 val) +{ + if (little_endian) + return le16_to_cpu((__force __le16)val); + else + return be16_to_cpu((__force __be16)val); +} + +static inline __virtio16 __cpu_to_virtio16(bool little_endian, u16 val) +{ + if (little_endian) + return (__force __virtio16)cpu_to_le16(val); + else + return (__force __virtio16)cpu_to_be16(val); +} + +static inline u32 __virtio32_to_cpu(bool little_endian, __virtio32 val) +{ + if (little_endian) + return le32_to_cpu((__force __le32)val); + else + return be32_to_cpu((__force __be32)val); +} + +static inline __virtio32 __cpu_to_virtio32(bool little_endian, u32 val) +{ + if (little_endian) + return (__force __virtio32)cpu_to_le32(val); + else + return (__force __virtio32)cpu_to_be32(val); +} + +static inline u64 __virtio64_to_cpu(bool little_endian, __virtio64 val) +{ + if (little_endian) + return le64_to_cpu((__force __le64)val); + else + return be64_to_cpu((__force __be64)val); +} + +static inline __virtio64 __cpu_to_virtio64(bool little_endian, u64 val) +{ + if (little_endian) + return (__force __virtio64)cpu_to_le64(val); + else + return (__force __virtio64)cpu_to_be64(val); +} + +/** + * __virtio_test_bit - helper to test feature bits + * + * For use by transports. Devices should normally use virtio_has_feature, + * which includes more checks. + * + * @udev: the transport device + * @fbit: the feature bit + */ +static inline bool __virtio_test_bit(struct udevice *udev, unsigned int fbit) +{ + struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev); + + /* Did you forget to fix assumptions on max features? */ + if (__builtin_constant_p(fbit)) + BUILD_BUG_ON(fbit >= 64); + else + WARN_ON(fbit >= 64); + + return uc_priv->features & BIT_ULL(fbit); +} + +/** + * __virtio_set_bit - helper to set feature bits + * + * For use by transports. + * + * @udev: the transport device + * @fbit: the feature bit + */ +static inline void __virtio_set_bit(struct udevice *udev, unsigned int fbit) +{ + struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev); + + /* Did you forget to fix assumptions on max features? */ + if (__builtin_constant_p(fbit)) + BUILD_BUG_ON(fbit >= 64); + else + WARN_ON(fbit >= 64); + + uc_priv->features |= BIT_ULL(fbit); +} + +/** + * __virtio_clear_bit - helper to clear feature bits + * + * For use by transports. + * + * @vdev: the transport device + * @fbit: the feature bit + */ +static inline void __virtio_clear_bit(struct udevice *udev, unsigned int fbit) +{ + struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev); + + /* Did you forget to fix assumptions on max features? */ + if (__builtin_constant_p(fbit)) + BUILD_BUG_ON(fbit >= 64); + else + WARN_ON(fbit >= 64); + + uc_priv->features &= ~BIT_ULL(fbit); +} + +/** + * virtio_has_feature - helper to determine if this device has this feature + * + * Note this API is only usable after the virtio device driver's bind phase, + * as the feature has been negotiated between the device and the driver. + * + * @vdev: the virtio device + * @fbit: the feature bit + */ +static inline bool virtio_has_feature(struct udevice *vdev, unsigned int fbit) +{ + if (!(vdev->flags & DM_FLAG_BOUND)) + WARN_ON(true); + + return __virtio_test_bit(vdev->parent, fbit); +} + +static inline bool virtio_legacy_is_little_endian(void) +{ +#ifdef __LITTLE_ENDIAN + return true; +#else + return false; +#endif +} + +static inline bool virtio_is_little_endian(struct udevice *vdev) +{ + struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(vdev->parent); + + return !uc_priv->legacy || virtio_legacy_is_little_endian(); +} + +/* Memory accessors */ +static inline u16 virtio16_to_cpu(struct udevice *vdev, __virtio16 val) +{ + return __virtio16_to_cpu(virtio_is_little_endian(vdev), val); +} + +static inline __virtio16 cpu_to_virtio16(struct udevice *vdev, u16 val) +{ + return __cpu_to_virtio16(virtio_is_little_endian(vdev), val); +} + +static inline u32 virtio32_to_cpu(struct udevice *vdev, __virtio32 val) +{ + return __virtio32_to_cpu(virtio_is_little_endian(vdev), val); +} + +static inline __virtio32 cpu_to_virtio32(struct udevice *vdev, u32 val) +{ + return __cpu_to_virtio32(virtio_is_little_endian(vdev), val); +} + +static inline u64 virtio64_to_cpu(struct udevice *vdev, __virtio64 val) +{ + return __virtio64_to_cpu(virtio_is_little_endian(vdev), val); +} + +static inline __virtio64 cpu_to_virtio64(struct udevice *vdev, u64 val) +{ + return __cpu_to_virtio64(virtio_is_little_endian(vdev), val); +} + +/* Read @count fields, @bytes each */ +static inline void __virtio_cread_many(struct udevice *vdev, + unsigned int offset, + void *buf, size_t count, size_t bytes) +{ + u32 old, gen; + int i; + + /* no need to check return value as generation can be optional */ + virtio_generation(vdev, &gen); + do { + old = gen; + + for (i = 0; i < count; i++) + virtio_get_config(vdev, offset + bytes * i, + buf + i * bytes, bytes); + + virtio_generation(vdev, &gen); + } while (gen != old); +} + +static inline void virtio_cread_bytes(struct udevice *vdev, + unsigned int offset, + void *buf, size_t len) +{ + __virtio_cread_many(vdev, offset, buf, len, 1); +} + +static inline u8 virtio_cread8(struct udevice *vdev, unsigned int offset) +{ + u8 ret; + + virtio_get_config(vdev, offset, &ret, sizeof(ret)); + return ret; +} + +static inline void virtio_cwrite8(struct udevice *vdev, + unsigned int offset, u8 val) +{ + virtio_set_config(vdev, offset, &val, sizeof(val)); +} + +static inline u16 virtio_cread16(struct udevice *vdev, + unsigned int offset) +{ + u16 ret; + + virtio_get_config(vdev, offset, &ret, sizeof(ret)); + return virtio16_to_cpu(vdev, (__force __virtio16)ret); +} + +static inline void virtio_cwrite16(struct udevice *vdev, + unsigned int offset, u16 val) +{ + val = (__force u16)cpu_to_virtio16(vdev, val); + virtio_set_config(vdev, offset, &val, sizeof(val)); +} + +static inline u32 virtio_cread32(struct udevice *vdev, + unsigned int offset) +{ + u32 ret; + + virtio_get_config(vdev, offset, &ret, sizeof(ret)); + return virtio32_to_cpu(vdev, (__force __virtio32)ret); +} + +static inline void virtio_cwrite32(struct udevice *vdev, + unsigned int offset, u32 val) +{ + val = (__force u32)cpu_to_virtio32(vdev, val); + virtio_set_config(vdev, offset, &val, sizeof(val)); +} + +static inline u64 virtio_cread64(struct udevice *vdev, + unsigned int offset) +{ + u64 ret; + + __virtio_cread_many(vdev, offset, &ret, 1, sizeof(ret)); + return virtio64_to_cpu(vdev, (__force __virtio64)ret); +} + +static inline void virtio_cwrite64(struct udevice *vdev, + unsigned int offset, u64 val) +{ + val = (__force u64)cpu_to_virtio64(vdev, val); + virtio_set_config(vdev, offset, &val, sizeof(val)); +} + +/* Config space read accessor */ +#define virtio_cread(vdev, structname, member, ptr) \ + do { \ + /* Must match the member's type, and be integer */ \ + if (!typecheck(typeof((((structname *)0)->member)), *(ptr))) \ + (*ptr) = 1; \ + \ + switch (sizeof(*ptr)) { \ + case 1: \ + *(ptr) = virtio_cread8(vdev, \ + offsetof(structname, member)); \ + break; \ + case 2: \ + *(ptr) = virtio_cread16(vdev, \ + offsetof(structname, member)); \ + break; \ + case 4: \ + *(ptr) = virtio_cread32(vdev, \ + offsetof(structname, member)); \ + break; \ + case 8: \ + *(ptr) = virtio_cread64(vdev, \ + offsetof(structname, member)); \ + break; \ + default: \ + WARN_ON(true); \ + } \ + } while (0) + +/* Config space write accessor */ +#define virtio_cwrite(vdev, structname, member, ptr) \ + do { \ + /* Must match the member's type, and be integer */ \ + if (!typecheck(typeof((((structname *)0)->member)), *(ptr))) \ + WARN_ON((*ptr) == 1); \ + \ + switch (sizeof(*ptr)) { \ + case 1: \ + virtio_cwrite8(vdev, \ + offsetof(structname, member), \ + *(ptr)); \ + break; \ + case 2: \ + virtio_cwrite16(vdev, \ + offsetof(structname, member), \ + *(ptr)); \ + break; \ + case 4: \ + virtio_cwrite32(vdev, \ + offsetof(structname, member), \ + *(ptr)); \ + break; \ + case 8: \ + virtio_cwrite64(vdev, \ + offsetof(structname, member), \ + *(ptr)); \ + break; \ + default: \ + WARN_ON(true); \ + } \ + } while (0) + +/* 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; \ + }) + +#endif /* __VIRTIO_H__ */ |