From 41e6215c6d29a7bbcee599411cdf0911fde1f09b Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 12 Nov 2020 14:37:52 +0100 Subject: [PATCH] virtio-mem: factor out calculation of the bit number within the subblock bitmap The calculation is already complicated enough, let's limit it to one location. Reviewed-by: Wei Yang Reviewed-by: Pankaj Gupta Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Pankaj Gupta Signed-off-by: David Hildenbrand Link: https://lore.kernel.org/r/20201112133815.13332-7-david@redhat.com Signed-off-by: Michael S. Tsirkin --- drivers/virtio/virtio_mem.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index 94451b401fba..30b4d07f5263 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -290,6 +290,16 @@ static int virtio_mem_mb_state_prepare_next_mb(struct virtio_mem *vm) _mb_id--) \ if (virtio_mem_mb_get_state(_vm, _mb_id) == _state) +/* + * Calculate the bit number in the subblock bitmap for the given subblock + * inside the given memory block. + */ +static int virtio_mem_sb_bitmap_bit_nr(struct virtio_mem *vm, + unsigned long mb_id, int sb_id) +{ + return (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb + sb_id; +} + /* * Mark all selected subblocks plugged. * @@ -299,7 +309,7 @@ static void virtio_mem_mb_set_sb_plugged(struct virtio_mem *vm, unsigned long mb_id, int sb_id, int count) { - const int bit = (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb + sb_id; + const int bit = virtio_mem_sb_bitmap_bit_nr(vm, mb_id, sb_id); __bitmap_set(vm->sb_bitmap, bit, count); } @@ -313,7 +323,7 @@ static void virtio_mem_mb_set_sb_unplugged(struct virtio_mem *vm, unsigned long mb_id, int sb_id, int count) { - const int bit = (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb + sb_id; + const int bit = virtio_mem_sb_bitmap_bit_nr(vm, mb_id, sb_id); __bitmap_clear(vm->sb_bitmap, bit, count); } @@ -325,7 +335,7 @@ static bool virtio_mem_mb_test_sb_plugged(struct virtio_mem *vm, unsigned long mb_id, int sb_id, int count) { - const int bit = (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb + sb_id; + const int bit = virtio_mem_sb_bitmap_bit_nr(vm, mb_id, sb_id); if (count == 1) return test_bit(bit, vm->sb_bitmap); @@ -342,7 +352,7 @@ static bool virtio_mem_mb_test_sb_unplugged(struct virtio_mem *vm, unsigned long mb_id, int sb_id, int count) { - const int bit = (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb + sb_id; + const int bit = virtio_mem_sb_bitmap_bit_nr(vm, mb_id, sb_id); /* TODO: Helper similar to bitmap_set() */ return find_next_bit(vm->sb_bitmap, bit + count, bit) >= bit + count; @@ -355,7 +365,7 @@ static bool virtio_mem_mb_test_sb_unplugged(struct virtio_mem *vm, static int virtio_mem_mb_first_unplugged_sb(struct virtio_mem *vm, unsigned long mb_id) { - const int bit = (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb; + const int bit = virtio_mem_sb_bitmap_bit_nr(vm, mb_id, 0); return find_next_zero_bit(vm->sb_bitmap, bit + vm->nb_sb_per_mb, bit) - bit; -- 2.20.1