From 0f14fd71c170278b35b46d8ae214473680905606 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Marc-Andr=C3=A9=20Lureau?= Date: Tue, 23 Jun 2015 17:56:37 +0200 Subject: [PATCH] ivshmem: factor out the incoming fifo handling MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Make a new function fifo_update_and_get() that can be reused by other functions (in next commits). Signed-off-by: Marc-André Lureau Reviewed-by: Claudio Fontana --- hw/misc/ivshmem.c | 59 ++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 39 insertions(+), 20 deletions(-) diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c index 2162d02..dd15f0e 100644 --- a/hw/misc/ivshmem.c +++ b/hw/misc/ivshmem.c @@ -441,6 +441,42 @@ static int increase_dynamic_storage(IVShmemState *s, int new_min_size) return 0; } +static bool fifo_update_and_get(IVShmemState *s, const uint8_t *buf, int size, + void *data, size_t len) +{ + const uint8_t *p; + uint32_t num; + + assert(len <= sizeof(long)); /* limitation of the fifo */ + if (fifo8_is_empty(&s->incoming_fifo) && size == len) { + memcpy(data, buf, size); + return true; + } + + IVSHMEM_DPRINTF("short read of %d bytes\n", size); + + num = MIN(size, sizeof(long) - fifo8_num_used(&s->incoming_fifo)); + fifo8_push_all(&s->incoming_fifo, buf, num); + + if (fifo8_num_used(&s->incoming_fifo) < len) { + assert(num == 0); + return false; + } + + size -= num; + buf += num; + p = fifo8_pop_buf(&s->incoming_fifo, len, &num); + assert(num == len); + + memcpy(data, p, len); + + if (size > 0) { + fifo8_push_all(&s->incoming_fifo, buf, size); + } + + return true; +} + static void ivshmem_read(void *opaque, const uint8_t *buf, int size) { IVShmemState *s = opaque; @@ -448,26 +484,9 @@ static void ivshmem_read(void *opaque, const uint8_t *buf, int size) int guest_max_eventfd; long incoming_posn; - if (fifo8_is_empty(&s->incoming_fifo) && size == sizeof(incoming_posn)) { - memcpy(&incoming_posn, buf, size); - } else { - const uint8_t *p; - uint32_t num; - - IVSHMEM_DPRINTF("short read of %d bytes\n", size); - num = MIN(size, sizeof(long) - fifo8_num_used(&s->incoming_fifo)); - fifo8_push_all(&s->incoming_fifo, buf, num); - if (fifo8_num_used(&s->incoming_fifo) < sizeof(incoming_posn)) { - return; - } - size -= num; - buf += num; - p = fifo8_pop_buf(&s->incoming_fifo, sizeof(incoming_posn), &num); - g_assert(num == sizeof(incoming_posn)); - memcpy(&incoming_posn, p, sizeof(incoming_posn)); - if (size > 0) { - fifo8_push_all(&s->incoming_fifo, buf, size); - } + if (!fifo_update_and_get(s, buf, size, + &incoming_posn, sizeof(incoming_posn))) { + return; } if (incoming_posn < -1) { -- 2.7.4