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/* 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__
#include <linux/bitops.h>
#include <linux/bug.h>
#define VIRTIO_ID_NET 1 /* virtio net */
#define VIRTIO_ID_BLOCK 2 /* virtio block */
#define VIRTIO_ID_RNG 4 /* virtio rng */
#define VIRTIO_ID_MAX_NUM 5
#define VIRTIO_NET_DRV_NAME "virtio-net"
#define VIRTIO_BLK_DRV_NAME "virtio-blk"
#define VIRTIO_RNG_DRV_NAME "virtio-rng"
/* 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__ */