uninorth: convert ffs(3) to ctz32()

It is not clear from the code how a 0 parameter should be handled by the
hardware.  Keep the same behavior as ffs(0) - 1 == -1.

Cc: Alexander Graf <agraf@suse.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1427124571-28598-4-git-send-email-stefanha@redhat.com
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

diff --git a/hw/pci-host/uninorth.c b/hw/pci-host/uninorth.c
index 53f2b59ae84f7fb8cd48086dc3c8979dc7d85b52..f0144eb7b01e29fddd23e82753ecdfbc1ed4a9f0 100644 (file)
--- a/hw/pci-host/uninorth.c
+++ b/hw/pci-host/uninorth.c
@@ -92,7 +92,10 @@ static uint32_t unin_get_config_reg(uint32_t reg, uint32_t addr)
         uint32_t slot, func;
 
         /* Grab CFA0 style values */
-        slot = ffs(reg & 0xfffff800) - 1;
+        slot = ctz32(reg & 0xfffff800);
+        if (slot == 32) {
+            slot = -1; /* XXX: should this be 0? */
+        }
         func = (reg >> 8) & 7;
 
         /* ... and then convert them to x86 format */