Merge tag 'qemu-sparc-20240110' of https://github.com/mcayland/qemu into staging

qemu-sparc queue

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# gpg: Signature made Wed 10 Jan 2024 07:00:08 GMT
# gpg:                using RSA key CC621AB98E82200D915CC9C45BC2C56FAE0F321F
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# gpg: Good signature from "Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>" [full]
# Primary key fingerprint: CC62 1AB9 8E82 200D 915C  C9C4 5BC2 C56F AE0F 321F

* tag 'qemu-sparc-20240110' of https://github.com/mcayland/qemu:
  util/fifo8: Introduce fifo8_peek_buf()
  util/fifo8: Allow fifo8_pop_buf() to not populate popped length

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 23 insertions, 5 deletions

diff --git a/util/fifo8.c b/util/fifo8.c
index de8fd0f1c5..4e01b532d9 100644
--- a/util/fifo8.c
+++ b/util/fifo8.c
@@ -66,19 +66,37 @@ uint8_t fifo8_pop(Fifo8 *fifo)
     return ret;
 }
 
-const uint8_t *fifo8_pop_buf(Fifo8 *fifo, uint32_t max, uint32_t *num)
+static const uint8_t *fifo8_peekpop_buf(Fifo8 *fifo, uint32_t max,
+                                        uint32_t *numptr, bool do_pop)
 {
     uint8_t *ret;
+    uint32_t num;
 
     assert(max > 0 && max <= fifo->num);
-    *num = MIN(fifo->capacity - fifo->head, max);
+    num = MIN(fifo->capacity - fifo->head, max);
     ret = &fifo->data[fifo->head];
-    fifo->head += *num;
-    fifo->head %= fifo->capacity;
-    fifo->num -= *num;
+
+    if (do_pop) {
+        fifo->head += num;
+        fifo->head %= fifo->capacity;
+        fifo->num -= num;
+    }
+    if (numptr) {
+        *numptr = num;
+    }
     return ret;
 }
 
+const uint8_t *fifo8_peek_buf(Fifo8 *fifo, uint32_t max, uint32_t *numptr)
+{
+    return fifo8_peekpop_buf(fifo, max, numptr, false);
+}
+
+const uint8_t *fifo8_pop_buf(Fifo8 *fifo, uint32_t max, uint32_t *numptr)
+{
+    return fifo8_peekpop_buf(fifo, max, numptr, true);
+}
+
 void fifo8_reset(Fifo8 *fifo)
 {
     fifo->num = 0;