hw/intc/allwinner-a10-pic: Don't use set_bit()/clear_bit()

The Allwinner PIC model uses set_bit() and clear_bit() to update the
values in its irq_pending[] array when an interrupt arrives.  However
it is using these functions wrongly: they work on an array of type
'long', and it is passing an array of type 'uint32_t'.  Because the
code manually figures out the right array element, this works on
little-endian hosts and on 32-bit big-endian hosts, where bits 0..31
in a 'long' are in the same place as they are in a 'uint32_t'.
However it breaks on 64-bit big-endian hosts.

Remove the use of set_bit() and clear_bit() in favour of using
deposit32() on the array element.  This fixes a bug where on
big-endian 64-bit hosts the guest kernel would hang early on in
bootup.

Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20230424152833.1334136-1-peter.maydell@linaro.org

diff --git a/hw/intc/allwinner-a10-pic.c b/hw/intc/allwinner-a10-pic.c
index 8cca124..4875e68 100644 (file)
--- a/hw/intc/allwinner-a10-pic.c
+++ b/hw/intc/allwinner-a10-pic.c
@@ -49,12 +49,9 @@ static void aw_a10_pic_update(AwA10PICState *s)
 static void aw_a10_pic_set_irq(void *opaque, int irq, int level)
 {
     AwA10PICState *s = opaque;
+    uint32_t *pending_reg = &s->irq_pending[irq / 32];
 
-    if (level) {
-        set_bit(irq % 32, (void *)&s->irq_pending[irq / 32]);
-    } else {
-        clear_bit(irq % 32, (void *)&s->irq_pending[irq / 32]);
-    }
+    *pending_reg = deposit32(*pending_reg, irq % 32, 1, level);
     aw_a10_pic_update(s);
 }