diff options
Diffstat (limited to '')
-rw-r--r-- | tools/io_uring/setup.c | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/tools/io_uring/setup.c b/tools/io_uring/setup.c new file mode 100644 index 000000000..0b50fcd78 --- /dev/null +++ b/tools/io_uring/setup.c @@ -0,0 +1,107 @@ +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/mman.h> +#include <unistd.h> +#include <errno.h> +#include <string.h> + +#include "liburing.h" + +static int io_uring_mmap(int fd, struct io_uring_params *p, + struct io_uring_sq *sq, struct io_uring_cq *cq) +{ + size_t size; + void *ptr; + int ret; + + sq->ring_sz = p->sq_off.array + p->sq_entries * sizeof(unsigned); + ptr = mmap(0, sq->ring_sz, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_POPULATE, fd, IORING_OFF_SQ_RING); + if (ptr == MAP_FAILED) + return -errno; + sq->khead = ptr + p->sq_off.head; + sq->ktail = ptr + p->sq_off.tail; + sq->kring_mask = ptr + p->sq_off.ring_mask; + sq->kring_entries = ptr + p->sq_off.ring_entries; + sq->kflags = ptr + p->sq_off.flags; + sq->kdropped = ptr + p->sq_off.dropped; + sq->array = ptr + p->sq_off.array; + + size = p->sq_entries * sizeof(struct io_uring_sqe); + sq->sqes = mmap(0, size, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_POPULATE, fd, + IORING_OFF_SQES); + if (sq->sqes == MAP_FAILED) { + ret = -errno; +err: + munmap(sq->khead, sq->ring_sz); + return ret; + } + + cq->ring_sz = p->cq_off.cqes + p->cq_entries * sizeof(struct io_uring_cqe); + ptr = mmap(0, cq->ring_sz, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_POPULATE, fd, IORING_OFF_CQ_RING); + if (ptr == MAP_FAILED) { + ret = -errno; + munmap(sq->sqes, p->sq_entries * sizeof(struct io_uring_sqe)); + goto err; + } + cq->khead = ptr + p->cq_off.head; + cq->ktail = ptr + p->cq_off.tail; + cq->kring_mask = ptr + p->cq_off.ring_mask; + cq->kring_entries = ptr + p->cq_off.ring_entries; + cq->koverflow = ptr + p->cq_off.overflow; + cq->cqes = ptr + p->cq_off.cqes; + return 0; +} + +/* + * For users that want to specify sq_thread_cpu or sq_thread_idle, this + * interface is a convenient helper for mmap()ing the rings. + * Returns -1 on error, or zero on success. On success, 'ring' + * contains the necessary information to read/write to the rings. + */ +int io_uring_queue_mmap(int fd, struct io_uring_params *p, struct io_uring *ring) +{ + int ret; + + memset(ring, 0, sizeof(*ring)); + ret = io_uring_mmap(fd, p, &ring->sq, &ring->cq); + if (!ret) + ring->ring_fd = fd; + return ret; +} + +/* + * Returns -1 on error, or zero on success. On success, 'ring' + * contains the necessary information to read/write to the rings. + */ +int io_uring_queue_init(unsigned entries, struct io_uring *ring, unsigned flags) +{ + struct io_uring_params p; + int fd, ret; + + memset(&p, 0, sizeof(p)); + p.flags = flags; + + fd = io_uring_setup(entries, &p); + if (fd < 0) + return fd; + + ret = io_uring_queue_mmap(fd, &p, ring); + if (ret) + close(fd); + + return ret; +} + +void io_uring_queue_exit(struct io_uring *ring) +{ + struct io_uring_sq *sq = &ring->sq; + struct io_uring_cq *cq = &ring->cq; + + munmap(sq->sqes, *sq->kring_entries * sizeof(struct io_uring_sqe)); + munmap(sq->khead, sq->ring_sz); + munmap(cq->khead, cq->ring_sz); + close(ring->ring_fd); +} |