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[PULL,34/56] fifo8: add skip parameter to fifo8_peekpop_bufptr()

Message ID 20240911121422.52585-35-philmd@linaro.org
State Accepted
Commit e8b33243bba7da5af8c1954017b549a04b9cfe40
Headers show
Series [PULL,01/56] hw/pci-host/designware: Declare CPU QOM types using DEFINE_TYPES() macro | expand

Commit Message

Philippe Mathieu-Daudé Sept. 11, 2024, 12:13 p.m. UTC 
From: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>

The skip parameter specifies the number of bytes to be skipped
from the current FIFO head before the peek or pop operation.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Octavian Purdila <tavip@google.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20240828122258.928947-4-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 util/fifo8.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/util/fifo8.c b/util/fifo8.c
index 5faa814a6e..62d6430b05 100644
--- a/util/fifo8.c
+++ b/util/fifo8.c
@@ -72,18 +72,20 @@  uint8_t fifo8_pop(Fifo8 *fifo)
 }
 
 static const uint8_t *fifo8_peekpop_bufptr(Fifo8 *fifo, uint32_t max,
-                                           uint32_t *numptr, bool do_pop)
+                                           uint32_t skip, uint32_t *numptr,
+                                           bool do_pop)
 {
     uint8_t *ret;
     uint32_t num, head;
 
     assert(max > 0 && max <= fifo->num);
-    head = fifo->head;
+    assert(skip <= fifo->num);
+    head = (fifo->head + skip) % fifo->capacity;
     num = MIN(fifo->capacity - head, max);
     ret = &fifo->data[head];
 
     if (do_pop) {
-        fifo->head += num;
+        fifo->head = head + num;
         fifo->head %= fifo->capacity;
         fifo->num -= num;
     }
@@ -95,12 +97,12 @@  static const uint8_t *fifo8_peekpop_bufptr(Fifo8 *fifo, uint32_t max,
 
 const uint8_t *fifo8_peek_bufptr(Fifo8 *fifo, uint32_t max, uint32_t *numptr)
 {
-    return fifo8_peekpop_bufptr(fifo, max, numptr, false);
+    return fifo8_peekpop_bufptr(fifo, max, 0, numptr, false);
 }
 
 const uint8_t *fifo8_pop_bufptr(Fifo8 *fifo, uint32_t max, uint32_t *numptr)
 {
-    return fifo8_peekpop_bufptr(fifo, max, numptr, true);
+    return fifo8_peekpop_bufptr(fifo, max, 0, numptr, true);
 }
 
 uint32_t fifo8_pop_buf(Fifo8 *fifo, uint8_t *dest, uint32_t destlen)