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authorNatanael Copa <ncopa@alpinelinux.org>2014-04-29 16:17:29 +0200
committerPeter Maydell <peter.maydell@linaro.org>2014-06-11 00:25:06 +0100
commit747eb78baa8803c58a1063e5da5b7f1e11b20eeb (patch)
tree03f2b63d9043ebfcd2c3f0ed8c7f05a2b7d96880
parentadf9d70b0dd754b4626fd0ae2b52014060cf7ba4 (diff)
downloadqemu-arm-747eb78baa8803c58a1063e5da5b7f1e11b20eeb.tar.gz
vhost: replace ffsl with ctzl
Avoid using the GNU extesion ffsl which is not implemented in musl libc. The atomic_xchg() means we know that vhost_log_chunk_t will never be larger than the 'long' type, so ctzl() is always sufficient. See also commit fbeadf50 (bitops: unify bitops_ffsl with the one in host-utils.h, call it bitops_ctzl) on why ctzl should be used instead of ffsl. Signed-off-by: Natanael Copa <ncopa@alpinelinux.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r--hw/virtio/vhost.c6
1 files changed, 2 insertions, 4 deletions
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 9e336ad81e..f62cfaf38e 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -41,7 +41,6 @@ static void vhost_dev_sync_region(struct vhost_dev *dev,
for (;from < to; ++from) {
vhost_log_chunk_t log;
- int bit;
/* We first check with non-atomic: much cheaper,
* and we expect non-dirty to be the common case. */
if (!*from) {
@@ -51,12 +50,11 @@ static void vhost_dev_sync_region(struct vhost_dev *dev,
/* Data must be read atomically. We don't really need barrier semantics
* but it's easier to use atomic_* than roll our own. */
log = atomic_xchg(from, 0);
- while ((bit = sizeof(log) > sizeof(int) ?
- ffsll(log) : ffs(log))) {
+ while (log) {
+ int bit = ctzl(log);
hwaddr page_addr;
hwaddr section_offset;
hwaddr mr_offset;
- bit -= 1;
page_addr = addr + bit * VHOST_LOG_PAGE;
section_offset = page_addr - section->offset_within_address_space;
mr_offset = section_offset + section->offset_within_region;