From ef8c7067c29d05d137a0e02e1d61854a16fd3d7f Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Fri, 17 Jun 2022 09:48:05 +0100 Subject: [PATCH] io_uring: change ->cqe_cached invariant for CQE32 With IORING_SETUP_CQE32 ->cqe_cached doesn't store a real address but rather an implicit offset into cqes. Store the real cqe pointer and increment it accordingly if CQE32. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/1ee1838cba16bed96381a006950b36ba640d998c.1655455613.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- io_uring/io_uring.c | 15 ++++++++++----- io_uring/io_uring.h | 8 ++------ 2 files changed, 12 insertions(+), 11 deletions(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 767606b89922..d3ab81fa2dbf 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -701,11 +701,8 @@ struct io_uring_cqe *__io_get_cqe(struct io_ring_ctx *ctx) { struct io_rings *rings = ctx->rings; unsigned int off = ctx->cached_cq_tail & (ctx->cq_entries - 1); - unsigned int shift = 0; unsigned int free, queued, len; - if (ctx->flags & IORING_SETUP_CQE32) - shift = 1; /* userspace may cheat modifying the tail, be safe and do min */ queued = min(__io_cqring_events(ctx), ctx->cq_entries); @@ -715,11 +712,19 @@ struct io_uring_cqe *__io_get_cqe(struct io_ring_ctx *ctx) if (!len) return NULL; - ctx->cached_cq_tail++; + if (ctx->flags & IORING_SETUP_CQE32) { + off <<= 1; + len <<= 1; + } + ctx->cqe_cached = &rings->cqes[off]; ctx->cqe_sentinel = ctx->cqe_cached + len; + + ctx->cached_cq_tail++; ctx->cqe_cached++; - return &rings->cqes[off << shift]; + if (ctx->flags & IORING_SETUP_CQE32) + ctx->cqe_cached++; + return &rings->cqes[off]; } static bool io_fill_cqe_aux(struct io_ring_ctx *ctx, diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h index dfb490e7cf45..558a860a93fc 100644 --- a/io_uring/io_uring.h +++ b/io_uring/io_uring.h @@ -22,14 +22,10 @@ static inline struct io_uring_cqe *io_get_cqe(struct io_ring_ctx *ctx) if (likely(ctx->cqe_cached < ctx->cqe_sentinel)) { struct io_uring_cqe *cqe = ctx->cqe_cached; - if (ctx->flags & IORING_SETUP_CQE32) { - unsigned int off = ctx->cqe_cached - ctx->rings->cqes; - - cqe += off; - } - ctx->cached_cq_tail++; ctx->cqe_cached++; + if (ctx->flags & IORING_SETUP_CQE32) + ctx->cqe_cached++; return cqe; } -- 2.25.1