| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef _LINUX_VIRTIO_CONFIG_H |
| #define _LINUX_VIRTIO_CONFIG_H |
| |
| #include <linux/err.h> |
| #include <linux/bug.h> |
| #include <linux/virtio.h> |
| #include <linux/virtio_byteorder.h> |
| #include <linux/compiler_types.h> |
| #include <uapi/linux/virtio_config.h> |
| |
| struct irq_affinity; |
| |
| struct virtio_shm_region { |
| u64 addr; |
| u64 len; |
| }; |
| |
| /** |
| * virtio_config_ops - operations for configuring a virtio device |
| * Note: Do not assume that a transport implements all of the operations |
| * getting/setting a value as a simple read/write! Generally speaking, |
| * any of @get/@set, @get_status/@set_status, or @get_features/ |
| * @finalize_features are NOT safe to be called from an atomic |
| * context. |
| * @enable_cbs: enable the callbacks |
| * vdev: the virtio_device |
| * @get: read the value of a configuration field |
| * vdev: the virtio_device |
| * offset: the offset of the configuration field |
| * buf: the buffer to write the field value into. |
| * len: the length of the buffer |
| * @set: write the value of a configuration field |
| * vdev: the virtio_device |
| * offset: the offset of the configuration field |
| * buf: the buffer to read the field value from. |
| * len: the length of the buffer |
| * @generation: config generation counter (optional) |
| * vdev: the virtio_device |
| * Returns the config generation counter |
| * @get_status: read the status byte |
| * vdev: the virtio_device |
| * Returns the status byte |
| * @set_status: write the status byte |
| * vdev: the virtio_device |
| * status: the new status byte |
| * @reset: reset the device |
| * vdev: the virtio device |
| * After this, status and feature negotiation must be done again |
| * Device must not be reset from its vq/config callbacks, or in |
| * parallel with being added/removed. |
| * @find_vqs: find virtqueues and instantiate them. |
| * vdev: the virtio_device |
| * nvqs: the number of virtqueues to find |
| * vqs: on success, includes new virtqueues |
| * callbacks: array of callbacks, for each virtqueue |
| * include a NULL entry for vqs that do not need a callback |
| * names: array of virtqueue names (mainly for debugging) |
| * include a NULL entry for vqs unused by driver |
| * Returns 0 on success or error status |
| * @del_vqs: free virtqueues found by find_vqs(). |
| * @get_features: get the array of feature bits for this device. |
| * vdev: the virtio_device |
| * Returns the first 64 feature bits (all we currently need). |
| * @finalize_features: confirm what device features we'll be using. |
| * vdev: the virtio_device |
| * This gives the final feature bits for the device: it can change |
| * the dev->feature bits if it wants. |
| * Returns 0 on success or error status |
| * @bus_name: return the bus name associated with the device (optional) |
| * vdev: the virtio_device |
| * This returns a pointer to the bus name a la pci_name from which |
| * the caller can then copy. |
| * @set_vq_affinity: set the affinity for a virtqueue (optional). |
| * @get_vq_affinity: get the affinity for a virtqueue (optional). |
| * @get_shm_region: get a shared memory region based on the index. |
| */ |
| typedef void vq_callback_t(struct virtqueue *); |
| struct virtio_config_ops { |
| void (*enable_cbs)(struct virtio_device *vdev); |
| void (*get)(struct virtio_device *vdev, unsigned offset, |
| void *buf, unsigned len); |
| void (*set)(struct virtio_device *vdev, unsigned offset, |
| const void *buf, unsigned len); |
| u32 (*generation)(struct virtio_device *vdev); |
| u8 (*get_status)(struct virtio_device *vdev); |
| void (*set_status)(struct virtio_device *vdev, u8 status); |
| void (*reset)(struct virtio_device *vdev); |
| int (*find_vqs)(struct virtio_device *, unsigned nvqs, |
| struct virtqueue *vqs[], vq_callback_t *callbacks[], |
| const char * const names[], const bool *ctx, |
| struct irq_affinity *desc); |
| void (*del_vqs)(struct virtio_device *); |
| u64 (*get_features)(struct virtio_device *vdev); |
| int (*finalize_features)(struct virtio_device *vdev); |
| const char *(*bus_name)(struct virtio_device *vdev); |
| int (*set_vq_affinity)(struct virtqueue *vq, |
| const struct cpumask *cpu_mask); |
| const struct cpumask *(*get_vq_affinity)(struct virtio_device *vdev, |
| int index); |
| bool (*get_shm_region)(struct virtio_device *vdev, |
| struct virtio_shm_region *region, u8 id); |
| }; |
| |
| /* If driver didn't advertise the feature, it will never appear. */ |
| void virtio_check_driver_offered_feature(const struct virtio_device *vdev, |
| unsigned int fbit); |
| |
| /** |
| * __virtio_test_bit - helper to test feature bits. For use by transports. |
| * Devices should normally use virtio_has_feature, |
| * which includes more checks. |
| * @vdev: the device |
| * @fbit: the feature bit |
| */ |
| static inline bool __virtio_test_bit(const struct virtio_device *vdev, |
| unsigned int fbit) |
| { |
| /* Did you forget to fix assumptions on max features? */ |
| if (__builtin_constant_p(fbit)) |
| BUILD_BUG_ON(fbit >= 64); |
| else |
| BUG_ON(fbit >= 64); |
| |
| return vdev->features & BIT_ULL(fbit); |
| } |
| |
| /** |
| * __virtio_set_bit - helper to set feature bits. For use by transports. |
| * @vdev: the device |
| * @fbit: the feature bit |
| */ |
| static inline void __virtio_set_bit(struct virtio_device *vdev, |
| unsigned int fbit) |
| { |
| /* Did you forget to fix assumptions on max features? */ |
| if (__builtin_constant_p(fbit)) |
| BUILD_BUG_ON(fbit >= 64); |
| else |
| BUG_ON(fbit >= 64); |
| |
| vdev->features |= BIT_ULL(fbit); |
| } |
| |
| /** |
| * __virtio_clear_bit - helper to clear feature bits. For use by transports. |
| * @vdev: the device |
| * @fbit: the feature bit |
| */ |
| static inline void __virtio_clear_bit(struct virtio_device *vdev, |
| unsigned int fbit) |
| { |
| /* Did you forget to fix assumptions on max features? */ |
| if (__builtin_constant_p(fbit)) |
| BUILD_BUG_ON(fbit >= 64); |
| else |
| BUG_ON(fbit >= 64); |
| |
| vdev->features &= ~BIT_ULL(fbit); |
| } |
| |
| /** |
| * virtio_has_feature - helper to determine if this device has this feature. |
| * @vdev: the device |
| * @fbit: the feature bit |
| */ |
| static inline bool virtio_has_feature(const struct virtio_device *vdev, |
| unsigned int fbit) |
| { |
| if (fbit < VIRTIO_TRANSPORT_F_START) |
| virtio_check_driver_offered_feature(vdev, fbit); |
| |
| return __virtio_test_bit(vdev, fbit); |
| } |
| |
| /** |
| * virtio_has_dma_quirk - determine whether this device has the DMA quirk |
| * @vdev: the device |
| */ |
| static inline bool virtio_has_dma_quirk(const struct virtio_device *vdev) |
| { |
| /* |
| * Note the reverse polarity of the quirk feature (compared to most |
| * other features), this is for compatibility with legacy systems. |
| */ |
| return !virtio_has_feature(vdev, VIRTIO_F_ACCESS_PLATFORM); |
| } |
| |
| static inline |
| struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev, |
| vq_callback_t *c, const char *n) |
| { |
| vq_callback_t *callbacks[] = { c }; |
| const char *names[] = { n }; |
| struct virtqueue *vq; |
| int err = vdev->config->find_vqs(vdev, 1, &vq, callbacks, names, NULL, |
| NULL); |
| if (err < 0) |
| return ERR_PTR(err); |
| return vq; |
| } |
| |
| static inline |
| int virtio_find_vqs(struct virtio_device *vdev, unsigned nvqs, |
| struct virtqueue *vqs[], vq_callback_t *callbacks[], |
| const char * const names[], |
| struct irq_affinity *desc) |
| { |
| return vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names, NULL, desc); |
| } |
| |
| static inline |
| int virtio_find_vqs_ctx(struct virtio_device *vdev, unsigned nvqs, |
| struct virtqueue *vqs[], vq_callback_t *callbacks[], |
| const char * const names[], const bool *ctx, |
| struct irq_affinity *desc) |
| { |
| return vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names, ctx, |
| desc); |
| } |
| |
| /** |
| * virtio_device_ready - enable vq use in probe function |
| * @vdev: the device |
| * |
| * Driver must call this to use vqs in the probe function. |
| * |
| * Note: vqs are enabled automatically after probe returns. |
| */ |
| static inline |
| void virtio_device_ready(struct virtio_device *dev) |
| { |
| unsigned status = dev->config->get_status(dev); |
| |
| if (dev->config->enable_cbs) |
| dev->config->enable_cbs(dev); |
| |
| BUG_ON(status & VIRTIO_CONFIG_S_DRIVER_OK); |
| dev->config->set_status(dev, status | VIRTIO_CONFIG_S_DRIVER_OK); |
| } |
| |
| static inline |
| const char *virtio_bus_name(struct virtio_device *vdev) |
| { |
| if (!vdev->config->bus_name) |
| return "virtio"; |
| return vdev->config->bus_name(vdev); |
| } |
| |
| /** |
| * virtqueue_set_affinity - setting affinity for a virtqueue |
| * @vq: the virtqueue |
| * @cpu: the cpu no. |
| * |
| * Pay attention the function are best-effort: the affinity hint may not be set |
| * due to config support, irq type and sharing. |
| * |
| */ |
| static inline |
| int virtqueue_set_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask) |
| { |
| struct virtio_device *vdev = vq->vdev; |
| if (vdev->config->set_vq_affinity) |
| return vdev->config->set_vq_affinity(vq, cpu_mask); |
| return 0; |
| } |
| |
| static inline |
| bool virtio_get_shm_region(struct virtio_device *vdev, |
| struct virtio_shm_region *region, u8 id) |
| { |
| if (!vdev->config->get_shm_region) |
| return false; |
| return vdev->config->get_shm_region(vdev, region, id); |
| } |
| |
| static inline bool virtio_is_little_endian(struct virtio_device *vdev) |
| { |
| return virtio_has_feature(vdev, VIRTIO_F_VERSION_1) || |
| virtio_legacy_is_little_endian(); |
| } |
| |
| /* Memory accessors */ |
| static inline u16 virtio16_to_cpu(struct virtio_device *vdev, __virtio16 val) |
| { |
| return __virtio16_to_cpu(virtio_is_little_endian(vdev), val); |
| } |
| |
| static inline __virtio16 cpu_to_virtio16(struct virtio_device *vdev, u16 val) |
| { |
| return __cpu_to_virtio16(virtio_is_little_endian(vdev), val); |
| } |
| |
| static inline u32 virtio32_to_cpu(struct virtio_device *vdev, __virtio32 val) |
| { |
| return __virtio32_to_cpu(virtio_is_little_endian(vdev), val); |
| } |
| |
| static inline __virtio32 cpu_to_virtio32(struct virtio_device *vdev, u32 val) |
| { |
| return __cpu_to_virtio32(virtio_is_little_endian(vdev), val); |
| } |
| |
| static inline u64 virtio64_to_cpu(struct virtio_device *vdev, __virtio64 val) |
| { |
| return __virtio64_to_cpu(virtio_is_little_endian(vdev), val); |
| } |
| |
| static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val) |
| { |
| return __cpu_to_virtio64(virtio_is_little_endian(vdev), val); |
| } |
| |
| #define virtio_to_cpu(vdev, x) \ |
| _Generic((x), \ |
| __u8: (x), \ |
| __virtio16: virtio16_to_cpu((vdev), (x)), \ |
| __virtio32: virtio32_to_cpu((vdev), (x)), \ |
| __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; \ |
| }) |
| |
| #ifdef CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS |
| int arch_has_restricted_virtio_memory_access(void); |
| #else |
| static inline int arch_has_restricted_virtio_memory_access(void) |
| { |
| return 0; |
| } |
| #endif /* CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS */ |
| |
| #endif /* _LINUX_VIRTIO_CONFIG_H */ |