add io_uring

1 files changed, 95 insertions, 0 deletions

diff --git a/include/kpl/io.h b/include/kpl/io.h
new file mode 100644
index 0000000..f353da2
--- /dev/null
+++ b/include/kpl/io.h
@@ -0,0 +1,95 @@
+/*
+ * IO uring
+ */
+
+#pragma once
+
+typedef enum : int32_t {
+    KPL_IO_URING_QUEUE_SIZE_POW2_MIN        = 12,
+    KPL_IO_URING_QUEUE_SIZE_POW2_MAX        = 20,
+    KPL_IO_URING_QUEUE_SIZE_POW2_DEFAULT    = 15
+} kpl_io_uring_enum;
+
+/*
+ * Per thread io_uring container, do not use across threads
+ * Operations are added to the submit queue by a functions specific to that operation
+ * Once one or more operations are added, call kpl_io_uring_submit to send the operations to the kernel
+ * Only one completed operation can be read at a time by kpl_io_uring_get_completed
+ * Uses defaults that require kernel version of 6.6 or greater
+ */
+typedef struct {
+    int32_t ring_fd, ring_queue_entries; // fd for submit, number of queue slots
+    uint32_t added_to_queue, submitted_to_kernel; //added to submission queue, added with io uring enter
+    uint32_t sq_cq_size, sqes_size; // using single mmap for kernel submission and completion
+    uint32_t *sring_head, *sring_tail, *sring_mask;
+    uint32_t *cring_head, *cring_tail, *cring_mask;
+    void *sring_ptr, *cring_ptr;
+    struct io_uring_sqe *sqes;
+    struct io_uring_cqe *cqes;
+    struct io_uring_params params;
+} kpl_io_uring; // must be zero initialized
+
+/*
+ * Called by owner thread
+ */
+int32_t kpl_io_uring_init(kpl_io_uring *io_uring, int32_t queue_size_pow2);
+
+/*
+ * Be sure no operations are in queue before calling
+ * Called by owner thread
+ */
+inline void kpl_io_uring_free(kpl_io_uring *io_uring) {
+    munmap(io_uring->sring_ptr, io_uring->sq_cq_size);
+    munmap(io_uring->sqes, io_uring->sqes_size);
+}
+
+/*
+ * Reads one from cqes, will call io uring enter if none are complete and submitted_to_kernel is not zero
+ * This will wait if io uring enter is called
+ * NULL for none completed
+ * If an error occurred, the error details will be on the kpl_task_object
+ */
+kpl_object_task *kpl_io_uring_get_completed(kpl_io_uring *io_uring);
+
+/*
+ * Submits all sqes (added_to_queue has total) in one io uring eneter
+ * This does not wait
+ */
+int32_t kpl_io_uring_submit(kpl_io_uring *io_uring);
+
+/*
+ * Only call this though one of the functions below to add an operation to the queue
+ */
+struct io_uring_sqe *kpl_io_uring_op(kpl_io_uring *io_uring, kpl_object_task *task, int32_t op, int32_t fd,
+    const void *addr, uint32_t len, uint64_t offset);
+
+inline bool kpl_io_uring_openat(kpl_io_uring *io_uring, kpl_object_task *task, int32_t dir_fd,
+    const char *path, int32_t flags, mode_t mode) {
+    struct io_uring_sqe *sqe = kpl_io_uring_op(io_uring, task, IORING_OP_OPENAT, dir_fd, path, mode, 0);
+    if (sqe)
+        sqe->open_flags = (uint32_t) flags;
+    return sqe;
+}
+
+inline bool kpl_io_uring_close(kpl_io_uring *io_uring, kpl_object_task *task, int32_t fd) {
+    return kpl_io_uring_op(io_uring, task, IORING_OP_CLOSE, fd, NULL, 0, 0);
+}
+
+inline bool kpl_io_uring_read(kpl_io_uring *io_uring, kpl_object_task *task, int32_t fd, void *buffer,
+    uint32_t byte_size, uint64_t offset) {
+    return kpl_io_uring_op(io_uring, task, IORING_OP_READ, fd, buffer, byte_size, offset);
+}
+
+inline bool kpl_io_uring_write(kpl_io_uring *uring, kpl_object_task *task, int32_t fd, void *buffer,
+    uint32_t byte_size, uint64_t offset) {
+    return kpl_io_uring_op(uring, task, IORING_OP_WRITE, fd, buffer, byte_size, offset);
+}
+
+inline bool kpl_io_uring_statx(kpl_io_uring *io_uring, kpl_object_task *task, int32_t dir_fd,
+    const char *path, int32_t flags, uint32_t mask, struct statx *statx_object) {
+    struct io_uring_sqe *sqe = kpl_io_uring_op(io_uring, task, IORING_OP_STATX, dir_fd, path, mask,
+        (uint64_t) statx_object);
+    if (sqe)
+        sqe->statx_flags = (uint32_t) flags;
+    return sqe;
+}