util/fifo8: Expose fifo8_pop_buf()

Extract fifo8_pop_buf() from hw/scsi/esp.c and expose
it as part of the <qemu/fifo8.h> API. This function takes
care of non-contiguous (wrapped) FIFO buffer (which is an
implementation detail).

Suggested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20240722160745.67904-7-philmd@linaro.org>

1 files changed, 3 insertions, 33 deletions

diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c
index 7e9657e..04c9a55 100644
--- a/hw/scsi/esp.c
+++ b/hw/scsi/esp.c
@@ -197,39 +197,9 @@ static uint8_t esp_fifo_pop(ESPState *s)
     return val;
 }
 
-static uint32_t esp_fifo8_pop_buf(Fifo8 *fifo, uint8_t *dest, int maxlen)
-{
-    const uint8_t *buf;
-    uint32_t n, n2;
-    int len;
-
-    if (maxlen == 0) {
-        return 0;
-    }
-
-    len = maxlen;
-    buf = fifo8_pop_bufptr(fifo, len, &n);
-    if (dest) {
-        memcpy(dest, buf, n);
-    }
-
-    /* Add FIFO wraparound if needed */
-    len -= n;
-    len = MIN(len, fifo8_num_used(fifo));
-    if (len) {
-        buf = fifo8_pop_bufptr(fifo, len, &n2);
-        if (dest) {
-            memcpy(&dest[n], buf, n2);
-        }
-        n += n2;
-    }
-
-    return n;
-}
-
 static uint32_t esp_fifo_pop_buf(ESPState *s, uint8_t *dest, int maxlen)
 {
-    uint32_t len = esp_fifo8_pop_buf(&s->fifo, dest, maxlen);
+    uint32_t len = fifo8_pop_buf(&s->fifo, dest, maxlen);
 
     esp_update_drq(s);
     return len;
@@ -335,7 +305,7 @@ static void do_command_phase(ESPState *s)
     if (!cmdlen || !s->current_dev) {
         return;
     }
-    esp_fifo8_pop_buf(&s->cmdfifo, buf, cmdlen);
+    fifo8_pop_buf(&s->cmdfifo, buf, cmdlen);
 
     current_lun = scsi_device_find(&s->bus, 0, s->current_dev->id, s->lun);
     if (!current_lun) {
@@ -381,7 +351,7 @@ static void do_message_phase(ESPState *s)
     /* Ignore extended messages for now */
     if (s->cmdfifo_cdb_offset) {
         int len = MIN(s->cmdfifo_cdb_offset, fifo8_num_used(&s->cmdfifo));
-        esp_fifo8_pop_buf(&s->cmdfifo, NULL, len);
+        fifo8_pop_buf(&s->cmdfifo, NULL, len);
         s->cmdfifo_cdb_offset = 0;
     }
 }