From 213d6f39efcfc4a6758d50b383a699b98190aad7 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 17 Jan 2019 21:40:30 -0700 Subject: Split src/io_uring.c up Let's have the various helpers be in usefully named functions, no need to bundle them all into the same one. Signed-off-by: Jens Axboe --- src/Makefile | 2 +- src/io_uring.c | 220 --------------------------------------------------------- src/queue.c | 140 ++++++++++++++++++++++++++++++++++++ src/setup.c | 92 ++++++++++++++++++++++++ 4 files changed, 233 insertions(+), 221 deletions(-) delete mode 100644 src/io_uring.c create mode 100644 src/queue.c create mode 100644 src/setup.c diff --git a/src/Makefile b/src/Makefile index 635f65a..3899680 100644 --- a/src/Makefile +++ b/src/Makefile @@ -22,7 +22,7 @@ endif all: $(all_targets) -liburing_srcs := io_uring.c syscall.c +liburing_srcs := setup.c queue.c syscall.c liburing_objs := $(patsubst %.c,%.ol,$(liburing_srcs)) liburing_sobjs := $(patsubst %.c,%.os,$(liburing_srcs)) diff --git a/src/io_uring.c b/src/io_uring.c deleted file mode 100644 index 7205914..0000000 --- a/src/io_uring.c +++ /dev/null @@ -1,220 +0,0 @@ -#include -#include -#include -#include -#include -#include - -#include "compat.h" -#include "io_uring.h" -#include "liburing.h" -#include "barrier.h" - -static int __io_uring_get_completion(int fd, struct io_uring_cq *cq, - struct io_uring_cqe **cqe_ptr, int wait) -{ - const unsigned mask = *cq->kring_mask; - unsigned head; - int ret; - - *cqe_ptr = NULL; - head = *cq->khead; - do { - read_barrier(); - if (head != *cq->ktail) { - *cqe_ptr = &cq->cqes[head & mask]; - break; - } - if (!wait) - break; - ret = io_uring_enter(fd, 0, 1, IORING_ENTER_GETEVENTS); - if (ret < 0) - return -errno; - } while (1); - - if (*cqe_ptr) { - *cq->khead = head + 1; - write_barrier(); - } - - return 0; -} - -/* - * Return an IO completion, if one is readily available - */ -int io_uring_get_completion(struct io_uring *ring, - struct io_uring_cqe **cqe_ptr) -{ - return __io_uring_get_completion(ring->ring_fd, &ring->cq, cqe_ptr, 0); -} - -/* - * Return an IO completion, waiting for it if necessary - */ -int io_uring_wait_completion(struct io_uring *ring, - struct io_uring_cqe **cqe_ptr) -{ - return __io_uring_get_completion(ring->ring_fd, &ring->cq, cqe_ptr, 1); -} - -/* - * Submit sqes acquired from io_uring_get_sqe() to the kernel. - * - * Returns number of sqes submitted - */ -int io_uring_submit(struct io_uring *ring) -{ - struct io_uring_sq *sq = &ring->sq; - const unsigned mask = *sq->kring_mask; - unsigned ktail, ktail_next, submitted; - - /* - * If we have pending IO in the kring, submit it first - */ - read_barrier(); - if (*sq->khead != *sq->ktail) { - submitted = *sq->kring_entries; - goto submit; - } - - if (sq->sqe_head == sq->sqe_tail) - return 0; - - /* - * Fill in sqes that we have queued up, adding them to the kernel ring - */ - submitted = 0; - ktail = ktail_next = *sq->ktail; - while (sq->sqe_head < sq->sqe_tail) { - ktail_next++; - read_barrier(); - if (ktail_next == *sq->khead) - break; - - sq->array[ktail & mask] = sq->sqe_head & mask; - ktail = ktail_next; - - sq->sqe_head++; - submitted++; - } - - if (!submitted) - return 0; - - if (*sq->ktail != ktail) { - write_barrier(); - *sq->ktail = ktail; - write_barrier(); - } - -submit: - return io_uring_enter(ring->ring_fd, submitted, 0, - IORING_ENTER_GETEVENTS); -} - -/* - * Return an sqe to fill. Application must later call io_uring_submit() - * when it's ready to tell the kernel about it. The caller may call this - * function multiple times before calling io_uring_submit(). - * - * Returns a vacant sqe, or NULL if we're full. - */ -struct io_uring_sqe *io_uring_get_sqe(struct io_uring *ring) -{ - struct io_uring_sq *sq = &ring->sq; - unsigned next = sq->sqe_tail + 1; - struct io_uring_sqe *sqe; - - /* - * All sqes are used - */ - if (next - sq->sqe_head > *sq->kring_entries) - return NULL; - - sqe = &sq->sqes[sq->sqe_tail & *sq->kring_mask]; - sq->sqe_tail = next; - return sqe; -} - -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; -} - -/* - * 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; - - memset(ring, 0, sizeof(*ring)); - ret = io_uring_mmap(fd, &p, &ring->sq, &ring->cq); - if (!ret) - ring->ring_fd = 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); -} diff --git a/src/queue.c b/src/queue.c new file mode 100644 index 0000000..b8788b3 --- /dev/null +++ b/src/queue.c @@ -0,0 +1,140 @@ +#include +#include +#include +#include +#include +#include + +#include "compat.h" +#include "io_uring.h" +#include "liburing.h" +#include "barrier.h" + +static int __io_uring_get_completion(struct io_uring *ring, + struct io_uring_cqe **cqe_ptr, int wait) +{ + struct io_uring_cq *cq = &ring->cq; + const unsigned mask = *cq->kring_mask; + unsigned head; + int ret; + + *cqe_ptr = NULL; + head = *cq->khead; + do { + read_barrier(); + if (head != *cq->ktail) { + *cqe_ptr = &cq->cqes[head & mask]; + break; + } + if (!wait) + break; + ret = io_uring_enter(ring->ring_fd, 0, 1, + IORING_ENTER_GETEVENTS); + if (ret < 0) + return -errno; + } while (1); + + if (*cqe_ptr) { + *cq->khead = head + 1; + write_barrier(); + } + + return 0; +} + +/* + * Return an IO completion, if one is readily available + */ +int io_uring_get_completion(struct io_uring *ring, + struct io_uring_cqe **cqe_ptr) +{ + return __io_uring_get_completion(ring, cqe_ptr, 0); +} + +/* + * Return an IO completion, waiting for it if necessary + */ +int io_uring_wait_completion(struct io_uring *ring, + struct io_uring_cqe **cqe_ptr) +{ + return __io_uring_get_completion(ring, cqe_ptr, 1); +} + +/* + * Submit sqes acquired from io_uring_get_sqe() to the kernel. + * + * Returns number of sqes submitted + */ +int io_uring_submit(struct io_uring *ring) +{ + struct io_uring_sq *sq = &ring->sq; + const unsigned mask = *sq->kring_mask; + unsigned ktail, ktail_next, submitted; + + /* + * If we have pending IO in the kring, submit it first + */ + read_barrier(); + if (*sq->khead != *sq->ktail) { + submitted = *sq->kring_entries; + goto submit; + } + + if (sq->sqe_head == sq->sqe_tail) + return 0; + + /* + * Fill in sqes that we have queued up, adding them to the kernel ring + */ + submitted = 0; + ktail = ktail_next = *sq->ktail; + while (sq->sqe_head < sq->sqe_tail) { + ktail_next++; + read_barrier(); + if (ktail_next == *sq->khead) + break; + + sq->array[ktail & mask] = sq->sqe_head & mask; + ktail = ktail_next; + + sq->sqe_head++; + submitted++; + } + + if (!submitted) + return 0; + + if (*sq->ktail != ktail) { + write_barrier(); + *sq->ktail = ktail; + write_barrier(); + } + +submit: + return io_uring_enter(ring->ring_fd, submitted, 0, + IORING_ENTER_GETEVENTS); +} + +/* + * Return an sqe to fill. Application must later call io_uring_submit() + * when it's ready to tell the kernel about it. The caller may call this + * function multiple times before calling io_uring_submit(). + * + * Returns a vacant sqe, or NULL if we're full. + */ +struct io_uring_sqe *io_uring_get_sqe(struct io_uring *ring) +{ + struct io_uring_sq *sq = &ring->sq; + unsigned next = sq->sqe_tail + 1; + struct io_uring_sqe *sqe; + + /* + * All sqes are used + */ + if (next - sq->sqe_head > *sq->kring_entries) + return NULL; + + sqe = &sq->sqes[sq->sqe_tail & *sq->kring_mask]; + sq->sqe_tail = next; + return sqe; +} diff --git a/src/setup.c b/src/setup.c new file mode 100644 index 0000000..eeb5fef --- /dev/null +++ b/src/setup.c @@ -0,0 +1,92 @@ +#include +#include +#include +#include +#include +#include + +#include "compat.h" +#include "io_uring.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; +} + +/* + * 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; + + memset(ring, 0, sizeof(*ring)); + ret = io_uring_mmap(fd, &p, &ring->sq, &ring->cq); + if (!ret) + ring->ring_fd = 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); +} -- cgit