};
/*
- * This data is shared with the application through the mmap at offset
- * IORING_OFF_SQ_RING.
+ * This data is shared with the application through the mmap at offsets
+ * IORING_OFF_SQ_RING and IORING_OFF_CQ_RING.
*
* The offsets to the member fields are published through struct
* io_sqring_offsets when calling io_uring_setup.
*/
-struct io_sq_ring {
+struct io_rings {
/*
* Head and tail offsets into the ring; the offsets need to be
* masked to get valid indices.
*
- * The kernel controls head and the application controls tail.
+ * The kernel controls head of the sq ring and the tail of the cq ring,
+ * and the application controls tail of the sq ring and the head of the
+ * cq ring.
*/
- struct io_uring r;
+ struct io_uring sq, cq;
/*
- * Bitmask to apply to head and tail offsets (constant, equals
+ * Bitmasks to apply to head and tail offsets (constant, equals
* ring_entries - 1)
*/
- u32 ring_mask;
- /* Ring size (constant, power of 2) */
- u32 ring_entries;
+ u32 sq_ring_mask, cq_ring_mask;
+ /* Ring sizes (constant, power of 2) */
+ u32 sq_ring_entries, cq_ring_entries;
/*
* Number of invalid entries dropped by the kernel due to
* invalid index stored in array
* counter includes all submissions that were dropped reaching
* the new SQ head (and possibly more).
*/
- u32 dropped;
+ u32 sq_dropped;
/*
* Runtime flags
*
* The application needs a full memory barrier before checking
* for IORING_SQ_NEED_WAKEUP after updating the sq tail.
*/
- u32 flags;
- /*
- * Ring buffer of indices into array of io_uring_sqe, which is
- * mmapped by the application using the IORING_OFF_SQES offset.
- *
- * This indirection could e.g. be used to assign fixed
- * io_uring_sqe entries to operations and only submit them to
- * the queue when needed.
- *
- * The kernel modifies neither the indices array nor the entries
- * array.
- */
- u32 array[];
-};
-
-/*
- * This data is shared with the application through the mmap at offset
- * IORING_OFF_CQ_RING.
- *
- * The offsets to the member fields are published through struct
- * io_cqring_offsets when calling io_uring_setup.
- */
-struct io_cq_ring {
- /*
- * Head and tail offsets into the ring; the offsets need to be
- * masked to get valid indices.
- *
- * The application controls head and the kernel tail.
- */
- struct io_uring r;
- /*
- * Bitmask to apply to head and tail offsets (constant, equals
- * ring_entries - 1)
- */
- u32 ring_mask;
- /* Ring size (constant, power of 2) */
- u32 ring_entries;
+ u32 sq_flags;
/*
* Number of completion events lost because the queue was full;
* this should be avoided by the application by making sure
* As completion events come in out of order this counter is not
* ordered with any other data.
*/
- u32 overflow;
+ u32 cq_overflow;
/*
* Ring buffer of completion events.
*
* produced, so the application is allowed to modify pending
* entries.
*/
- struct io_uring_cqe cqes[];
+ struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp;
};
struct io_mapped_ubuf {
bool compat;
bool account_mem;
- /* SQ ring */
- struct io_sq_ring *sq_ring;
+ /*
+ * Ring buffer of indices into array of io_uring_sqe, which is
+ * mmapped by the application using the IORING_OFF_SQES offset.
+ *
+ * This indirection could e.g. be used to assign fixed
+ * io_uring_sqe entries to operations and only submit them to
+ * the queue when needed.
+ *
+ * The kernel modifies neither the indices array nor the entries
+ * array.
+ */
+ u32 *sq_array;
unsigned cached_sq_head;
unsigned sq_entries;
unsigned sq_mask;
struct completion sqo_thread_started;
struct {
- /* CQ ring */
- struct io_cq_ring *cq_ring;
unsigned cached_cq_tail;
unsigned cq_entries;
unsigned cq_mask;
struct eventfd_ctx *cq_ev_fd;
} ____cacheline_aligned_in_smp;
+ struct io_rings *rings;
+
/*
* If used, fixed file set. Writers must ensure that ->refs is dead,
* readers must ensure that ->refs is alive as long as the file* is
if ((req->flags & (REQ_F_IO_DRAIN|REQ_F_IO_DRAINED)) != REQ_F_IO_DRAIN)
return false;
- return req->sequence != ctx->cached_cq_tail + ctx->sq_ring->dropped;
+ return req->sequence != ctx->cached_cq_tail + ctx->rings->sq_dropped;
}
static struct io_kiocb *io_get_deferred_req(struct io_ring_ctx *ctx)
static void __io_commit_cqring(struct io_ring_ctx *ctx)
{
- struct io_cq_ring *ring = ctx->cq_ring;
+ struct io_rings *rings = ctx->rings;
- if (ctx->cached_cq_tail != READ_ONCE(ring->r.tail)) {
+ if (ctx->cached_cq_tail != READ_ONCE(rings->cq.tail)) {
/* order cqe stores with ring update */
- smp_store_release(&ring->r.tail, ctx->cached_cq_tail);
+ smp_store_release(&rings->cq.tail, ctx->cached_cq_tail);
if (wq_has_sleeper(&ctx->cq_wait)) {
wake_up_interruptible(&ctx->cq_wait);
static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx)
{
- struct io_cq_ring *ring = ctx->cq_ring;
+ struct io_rings *rings = ctx->rings;
unsigned tail;
tail = ctx->cached_cq_tail;
* control dependency is enough as we're using WRITE_ONCE to
* fill the cq entry
*/
- if (tail - READ_ONCE(ring->r.head) == ring->ring_entries)
+ if (tail - READ_ONCE(rings->cq.head) == rings->cq_ring_entries)
return NULL;
ctx->cached_cq_tail++;
- return &ring->cqes[tail & ctx->cq_mask];
+ return &rings->cqes[tail & ctx->cq_mask];
}
static void io_cqring_fill_event(struct io_ring_ctx *ctx, u64 ki_user_data,
WRITE_ONCE(cqe->res, res);
WRITE_ONCE(cqe->flags, 0);
} else {
- unsigned overflow = READ_ONCE(ctx->cq_ring->overflow);
+ unsigned overflow = READ_ONCE(ctx->rings->cq_overflow);
- WRITE_ONCE(ctx->cq_ring->overflow, overflow + 1);
+ WRITE_ONCE(ctx->rings->cq_overflow, overflow + 1);
}
}
io_free_req(req);
}
-static unsigned io_cqring_events(struct io_cq_ring *ring)
+static unsigned io_cqring_events(struct io_rings *rings)
{
/* See comment at the top of this file */
smp_rmb();
- return READ_ONCE(ring->r.tail) - READ_ONCE(ring->r.head);
+ return READ_ONCE(rings->cq.tail) - READ_ONCE(rings->cq.head);
}
/*
* If we do, we can potentially be spinning for commands that
* already triggered a CQE (eg in error).
*/
- if (io_cqring_events(ctx->cq_ring))
+ if (io_cqring_events(ctx->rings))
break;
/*
static void io_commit_sqring(struct io_ring_ctx *ctx)
{
- struct io_sq_ring *ring = ctx->sq_ring;
+ struct io_rings *rings = ctx->rings;
- if (ctx->cached_sq_head != READ_ONCE(ring->r.head)) {
+ if (ctx->cached_sq_head != READ_ONCE(rings->sq.head)) {
/*
* Ensure any loads from the SQEs are done at this point,
* since once we write the new head, the application could
* write new data to them.
*/
- smp_store_release(&ring->r.head, ctx->cached_sq_head);
+ smp_store_release(&rings->sq.head, ctx->cached_sq_head);
}
}
*/
static bool io_get_sqring(struct io_ring_ctx *ctx, struct sqe_submit *s)
{
- struct io_sq_ring *ring = ctx->sq_ring;
+ struct io_rings *rings = ctx->rings;
+ u32 *sq_array = ctx->sq_array;
unsigned head;
/*
*/
head = ctx->cached_sq_head;
/* make sure SQ entry isn't read before tail */
- if (head == smp_load_acquire(&ring->r.tail))
+ if (head == smp_load_acquire(&rings->sq.tail))
return false;
- head = READ_ONCE(ring->array[head & ctx->sq_mask]);
+ head = READ_ONCE(sq_array[head & ctx->sq_mask]);
if (head < ctx->sq_entries) {
s->index = head;
s->sqe = &ctx->sq_sqes[head];
/* drop invalid entries */
ctx->cached_sq_head++;
- ring->dropped++;
+ rings->sq_dropped++;
return false;
}
TASK_INTERRUPTIBLE);
/* Tell userspace we may need a wakeup call */
- ctx->sq_ring->flags |= IORING_SQ_NEED_WAKEUP;
+ ctx->rings->sq_flags |= IORING_SQ_NEED_WAKEUP;
/* make sure to read SQ tail after writing flags */
smp_mb();
schedule();
finish_wait(&ctx->sqo_wait, &wait);
- ctx->sq_ring->flags &= ~IORING_SQ_NEED_WAKEUP;
+ ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP;
continue;
}
finish_wait(&ctx->sqo_wait, &wait);
- ctx->sq_ring->flags &= ~IORING_SQ_NEED_WAKEUP;
+ ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP;
}
i = 0;
static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
const sigset_t __user *sig, size_t sigsz)
{
- struct io_cq_ring *ring = ctx->cq_ring;
+ struct io_rings *rings = ctx->rings;
int ret;
- if (io_cqring_events(ring) >= min_events)
+ if (io_cqring_events(rings) >= min_events)
return 0;
if (sig) {
return ret;
}
- ret = wait_event_interruptible(ctx->wait, io_cqring_events(ring) >= min_events);
+ ret = wait_event_interruptible(ctx->wait, io_cqring_events(rings) >= min_events);
restore_saved_sigmask_unless(ret == -ERESTARTSYS);
if (ret == -ERESTARTSYS)
ret = -EINTR;
- return READ_ONCE(ring->r.head) == READ_ONCE(ring->r.tail) ? ret : 0;
+ return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;
}
static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
return (void *) __get_free_pages(gfp_flags, get_order(size));
}
+static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries,
+ size_t *sq_offset)
+{
+ struct io_rings *rings;
+ size_t off, sq_array_size;
+
+ off = struct_size(rings, cqes, cq_entries);
+ if (off == SIZE_MAX)
+ return SIZE_MAX;
+
+#ifdef CONFIG_SMP
+ off = ALIGN(off, SMP_CACHE_BYTES);
+ if (off == 0)
+ return SIZE_MAX;
+#endif
+
+ sq_array_size = array_size(sizeof(u32), sq_entries);
+ if (sq_array_size == SIZE_MAX)
+ return SIZE_MAX;
+
+ if (check_add_overflow(off, sq_array_size, &off))
+ return SIZE_MAX;
+
+ if (sq_offset)
+ *sq_offset = off;
+
+ return off;
+}
+
static unsigned long ring_pages(unsigned sq_entries, unsigned cq_entries)
{
- struct io_sq_ring *sq_ring;
- struct io_cq_ring *cq_ring;
- size_t bytes;
+ size_t pages;
- bytes = struct_size(sq_ring, array, sq_entries);
- bytes += array_size(sizeof(struct io_uring_sqe), sq_entries);
- bytes += struct_size(cq_ring, cqes, cq_entries);
+ pages = (size_t)1 << get_order(
+ rings_size(sq_entries, cq_entries, NULL));
+ pages += (size_t)1 << get_order(
+ array_size(sizeof(struct io_uring_sqe), sq_entries));
- return (bytes + PAGE_SIZE - 1) / PAGE_SIZE;
+ return pages;
}
static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx)
}
#endif
- io_mem_free(ctx->sq_ring);
+ io_mem_free(ctx->rings);
io_mem_free(ctx->sq_sqes);
- io_mem_free(ctx->cq_ring);
percpu_ref_exit(&ctx->refs);
if (ctx->account_mem)
* io_commit_cqring
*/
smp_rmb();
- if (READ_ONCE(ctx->sq_ring->r.tail) - ctx->cached_sq_head !=
- ctx->sq_ring->ring_entries)
+ if (READ_ONCE(ctx->rings->sq.tail) - ctx->cached_sq_head !=
+ ctx->rings->sq_ring_entries)
mask |= EPOLLOUT | EPOLLWRNORM;
- if (READ_ONCE(ctx->cq_ring->r.head) != ctx->cached_cq_tail)
+ if (READ_ONCE(ctx->rings->sq.head) != ctx->cached_cq_tail)
mask |= EPOLLIN | EPOLLRDNORM;
return mask;
switch (offset) {
case IORING_OFF_SQ_RING:
- ptr = ctx->sq_ring;
+ case IORING_OFF_CQ_RING:
+ ptr = ctx->rings;
break;
case IORING_OFF_SQES:
ptr = ctx->sq_sqes;
break;
- case IORING_OFF_CQ_RING:
- ptr = ctx->cq_ring;
- break;
default:
return -EINVAL;
}
static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
struct io_uring_params *p)
{
- struct io_sq_ring *sq_ring;
- struct io_cq_ring *cq_ring;
- size_t size;
+ struct io_rings *rings;
+ size_t size, sq_array_offset;
- sq_ring = io_mem_alloc(struct_size(sq_ring, array, p->sq_entries));
- if (!sq_ring)
+ size = rings_size(p->sq_entries, p->cq_entries, &sq_array_offset);
+ if (size == SIZE_MAX)
+ return -EOVERFLOW;
+
+ rings = io_mem_alloc(size);
+ if (!rings)
return -ENOMEM;
- ctx->sq_ring = sq_ring;
- sq_ring->ring_mask = p->sq_entries - 1;
- sq_ring->ring_entries = p->sq_entries;
- ctx->sq_mask = sq_ring->ring_mask;
- ctx->sq_entries = sq_ring->ring_entries;
+ ctx->rings = rings;
+ ctx->sq_array = (u32 *)((char *)rings + sq_array_offset);
+ rings->sq_ring_mask = p->sq_entries - 1;
+ rings->cq_ring_mask = p->cq_entries - 1;
+ rings->sq_ring_entries = p->sq_entries;
+ rings->cq_ring_entries = p->cq_entries;
+ ctx->sq_mask = rings->sq_ring_mask;
+ ctx->cq_mask = rings->cq_ring_mask;
+ ctx->sq_entries = rings->sq_ring_entries;
+ ctx->cq_entries = rings->cq_ring_entries;
size = array_size(sizeof(struct io_uring_sqe), p->sq_entries);
if (size == SIZE_MAX)
if (!ctx->sq_sqes)
return -ENOMEM;
- cq_ring = io_mem_alloc(struct_size(cq_ring, cqes, p->cq_entries));
- if (!cq_ring)
- return -ENOMEM;
-
- ctx->cq_ring = cq_ring;
- cq_ring->ring_mask = p->cq_entries - 1;
- cq_ring->ring_entries = p->cq_entries;
- ctx->cq_mask = cq_ring->ring_mask;
- ctx->cq_entries = cq_ring->ring_entries;
return 0;
}
goto err;
memset(&p->sq_off, 0, sizeof(p->sq_off));
- p->sq_off.head = offsetof(struct io_sq_ring, r.head);
- p->sq_off.tail = offsetof(struct io_sq_ring, r.tail);
- p->sq_off.ring_mask = offsetof(struct io_sq_ring, ring_mask);
- p->sq_off.ring_entries = offsetof(struct io_sq_ring, ring_entries);
- p->sq_off.flags = offsetof(struct io_sq_ring, flags);
- p->sq_off.dropped = offsetof(struct io_sq_ring, dropped);
- p->sq_off.array = offsetof(struct io_sq_ring, array);
+ p->sq_off.head = offsetof(struct io_rings, sq.head);
+ p->sq_off.tail = offsetof(struct io_rings, sq.tail);
+ p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask);
+ p->sq_off.ring_entries = offsetof(struct io_rings, sq_ring_entries);
+ p->sq_off.flags = offsetof(struct io_rings, sq_flags);
+ p->sq_off.dropped = offsetof(struct io_rings, sq_dropped);
+ p->sq_off.array = (char *)ctx->sq_array - (char *)ctx->rings;
memset(&p->cq_off, 0, sizeof(p->cq_off));
- p->cq_off.head = offsetof(struct io_cq_ring, r.head);
- p->cq_off.tail = offsetof(struct io_cq_ring, r.tail);
- p->cq_off.ring_mask = offsetof(struct io_cq_ring, ring_mask);
- p->cq_off.ring_entries = offsetof(struct io_cq_ring, ring_entries);
- p->cq_off.overflow = offsetof(struct io_cq_ring, overflow);
- p->cq_off.cqes = offsetof(struct io_cq_ring, cqes);
+ p->cq_off.head = offsetof(struct io_rings, cq.head);
+ p->cq_off.tail = offsetof(struct io_rings, cq.tail);
+ p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask);
+ p->cq_off.ring_entries = offsetof(struct io_rings, cq_ring_entries);
+ p->cq_off.overflow = offsetof(struct io_rings, cq_overflow);
+ p->cq_off.cqes = offsetof(struct io_rings, cqes);
return ret;
err:
io_ring_ctx_wait_and_kill(ctx);
projects / linux-2.6-microblaze.git / commitdiff