From c31c7ec4bcd7bb0d7b28897d730431c02b9d4ea1 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Wed, 24 Jul 2019 09:24:50 +0100 Subject: src/Makefile: keep private headers in It is not possible to install barrier.h and compat.h into the top-level /usr/include directly since they are likely to conflict with other software. io_uring.h could be confused with the system's kernel header file. Put liburing headers into so there is no chance of conflicts or confusion. Existing applications continue to build successfully since the location of is unchanged. In-tree examples and tests require modification because src/liburing.h is moved to src/include/liburing.h. Signed-off-by: Stefan Hajnoczi Signed-off-by: Jens Axboe --- src/include/liburing.h | 221 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 221 insertions(+) create mode 100644 src/include/liburing.h (limited to 'src/include/liburing.h') diff --git a/src/include/liburing.h b/src/include/liburing.h new file mode 100644 index 0000000..fb78cd3 --- /dev/null +++ b/src/include/liburing.h @@ -0,0 +1,221 @@ +#ifndef LIB_URING_H +#define LIB_URING_H + +#ifdef __cplusplus +extern "C" { +#endif + +#include +#include +#include +#include +#include "liburing/compat.h" +#include "liburing/io_uring.h" +#include "liburing/barrier.h" + +/* + * Library interface to io_uring + */ +struct io_uring_sq { + unsigned *khead; + unsigned *ktail; + unsigned *kring_mask; + unsigned *kring_entries; + unsigned *kflags; + unsigned *kdropped; + unsigned *array; + struct io_uring_sqe *sqes; + + unsigned sqe_head; + unsigned sqe_tail; + + size_t ring_sz; + void *ring_ptr; +}; + +struct io_uring_cq { + unsigned *khead; + unsigned *ktail; + unsigned *kring_mask; + unsigned *kring_entries; + unsigned *koverflow; + struct io_uring_cqe *cqes; + + size_t ring_sz; + void *ring_ptr; +}; + +struct io_uring { + struct io_uring_sq sq; + struct io_uring_cq cq; + unsigned flags; + int ring_fd; +}; + +/* + * System calls + */ +extern int io_uring_setup(unsigned entries, struct io_uring_params *p); +extern int io_uring_enter(unsigned fd, unsigned to_submit, + unsigned min_complete, unsigned flags, sigset_t *sig); +extern int io_uring_register(int fd, unsigned int opcode, const void *arg, + unsigned int nr_args); + +/* + * Library interface + */ +extern int io_uring_queue_init(unsigned entries, struct io_uring *ring, + unsigned flags); +extern int io_uring_queue_mmap(int fd, struct io_uring_params *p, + struct io_uring *ring); +extern void io_uring_queue_exit(struct io_uring *ring); +extern int io_uring_peek_cqe(struct io_uring *ring, + struct io_uring_cqe **cqe_ptr); +extern int io_uring_wait_cqe(struct io_uring *ring, + struct io_uring_cqe **cqe_ptr); +extern int io_uring_submit(struct io_uring *ring); +extern int io_uring_submit_and_wait(struct io_uring *ring, unsigned wait_nr); +extern struct io_uring_sqe *io_uring_get_sqe(struct io_uring *ring); + +extern int io_uring_register_buffers(struct io_uring *ring, + const struct iovec *iovecs, + unsigned nr_iovecs); +extern int io_uring_unregister_buffers(struct io_uring *ring); +extern int io_uring_register_files(struct io_uring *ring, const int *files, + unsigned nr_files); +extern int io_uring_unregister_files(struct io_uring *ring); +extern int io_uring_register_eventfd(struct io_uring *ring, int fd); +extern int io_uring_unregister_eventfd(struct io_uring *ring); + +#define io_uring_for_each_cqe(ring, head, cqe) \ + /* smp_load_acquire() enforces the order of tail and CQE reads. */ \ + for (head = *(ring)->cq.khead; \ + (cqe = (head != smp_load_acquire((ring)->cq.ktail) ? \ + &(ring)->cq.cqes[head & (*(ring)->cq.kring_mask)] : NULL)); \ + head++) \ + + +/* + * Must be called after io_uring_for_each_cqe() + */ +static inline void io_uring_cq_advance(struct io_uring *ring, + unsigned nr) +{ + if (nr) { + struct io_uring_cq *cq = &ring->cq; + + /* + * Ensure that the kernel only sees the new value of the head + * index after the CQEs have been read. + */ + smp_store_release(cq->khead, *cq->khead + nr); + } +} + +/* + * Must be called after io_uring_{peek,wait}_cqe() after the cqe has + * been processed by the application. + */ +static inline void io_uring_cqe_seen(struct io_uring *ring, + struct io_uring_cqe *cqe) +{ + if (cqe) + io_uring_cq_advance(ring, 1); +} + +/* + * Command prep helpers + */ +static inline void io_uring_sqe_set_data(struct io_uring_sqe *sqe, void *data) +{ + sqe->user_data = (unsigned long) data; +} + +static inline void *io_uring_cqe_get_data(struct io_uring_cqe *cqe) +{ + return (void *) (uintptr_t) cqe->user_data; +} + +static inline void io_uring_sqe_set_flags(struct io_uring_sqe *sqe, + unsigned flags) +{ + sqe->flags = flags; +} + +static inline void io_uring_prep_rw(int op, struct io_uring_sqe *sqe, int fd, + const void *addr, unsigned len, + off_t offset) +{ + memset(sqe, 0, sizeof(*sqe)); + sqe->opcode = op; + sqe->fd = fd; + sqe->off = offset; + sqe->addr = (unsigned long) addr; + sqe->len = len; +} + +static inline void io_uring_prep_readv(struct io_uring_sqe *sqe, int fd, + const struct iovec *iovecs, + unsigned nr_vecs, off_t offset) +{ + io_uring_prep_rw(IORING_OP_READV, sqe, fd, iovecs, nr_vecs, offset); +} + +static inline void io_uring_prep_read_fixed(struct io_uring_sqe *sqe, int fd, + void *buf, unsigned nbytes, + off_t offset) +{ + io_uring_prep_rw(IORING_OP_READ_FIXED, sqe, fd, buf, nbytes, offset); +} + +static inline void io_uring_prep_writev(struct io_uring_sqe *sqe, int fd, + const struct iovec *iovecs, + unsigned nr_vecs, off_t offset) +{ + io_uring_prep_rw(IORING_OP_WRITEV, sqe, fd, iovecs, nr_vecs, offset); +} + +static inline void io_uring_prep_write_fixed(struct io_uring_sqe *sqe, int fd, + const void *buf, unsigned nbytes, + off_t offset) +{ + io_uring_prep_rw(IORING_OP_WRITE_FIXED, sqe, fd, buf, nbytes, offset); +} + +static inline void io_uring_prep_poll_add(struct io_uring_sqe *sqe, int fd, + short poll_mask) +{ + memset(sqe, 0, sizeof(*sqe)); + sqe->opcode = IORING_OP_POLL_ADD; + sqe->fd = fd; + sqe->poll_events = poll_mask; +} + +static inline void io_uring_prep_poll_remove(struct io_uring_sqe *sqe, + void *user_data) +{ + memset(sqe, 0, sizeof(*sqe)); + sqe->opcode = IORING_OP_POLL_REMOVE; + sqe->addr = (unsigned long) user_data; +} + +static inline void io_uring_prep_fsync(struct io_uring_sqe *sqe, int fd, + unsigned fsync_flags) +{ + memset(sqe, 0, sizeof(*sqe)); + sqe->opcode = IORING_OP_FSYNC; + sqe->fd = fd; + sqe->fsync_flags = fsync_flags; +} + +static inline void io_uring_prep_nop(struct io_uring_sqe *sqe) +{ + memset(sqe, 0, sizeof(*sqe)); + sqe->opcode = IORING_OP_NOP; +} + +#ifdef __cplusplus +} +#endif + +#endif -- cgit