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    Subject[PATCH v1 18/29] virtio-mem: factor out calculation of the bit number within the sb_states bitmap
    Date
    The calculation is already complicated enough, let's limit it to one
    location.

    Cc: "Michael S. Tsirkin" <mst@redhat.com>
    Cc: Jason Wang <jasowang@redhat.com>
    Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
    Signed-off-by: David Hildenbrand <david@redhat.com>
    ---
    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 2cc497ad8298..73ff6e9ba839 100644
    --- a/drivers/virtio/virtio_mem.c
    +++ b/drivers/virtio/virtio_mem.c
    @@ -327,6 +327,16 @@ static int virtio_mem_sbm_mb_states_prepare_next_mb(struct virtio_mem *vm)
    _mb_id--) \
    if (virtio_mem_sbm_get_mb_state(_vm, _mb_id) == _state)

    +/*
    + * Calculate the bit number in the sb_states bitmap for the given subblock
    + * inside the given memory block.
    + */
    +static int virtio_mem_sbm_sb_state_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.
    *
    @@ -336,7 +346,7 @@ static void virtio_mem_sbm_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_sbm_sb_state_bit_nr(vm, mb_id, sb_id);

    __bitmap_set(vm->sbm.sb_states, bit, count);
    }
    @@ -350,7 +360,7 @@ static void virtio_mem_sbm_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_sbm_sb_state_bit_nr(vm, mb_id, sb_id);

    __bitmap_clear(vm->sbm.sb_states, bit, count);
    }
    @@ -362,7 +372,7 @@ static bool virtio_mem_sbm_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_sbm_sb_state_bit_nr(vm, mb_id, sb_id);

    if (count == 1)
    return test_bit(bit, vm->sbm.sb_states);
    @@ -379,7 +389,7 @@ static bool virtio_mem_sbm_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_sbm_sb_state_bit_nr(vm, mb_id, sb_id);

    /* TODO: Helper similar to bitmap_set() */
    return find_next_bit(vm->sbm.sb_states, bit + count, bit) >=
    @@ -393,7 +403,7 @@ static bool virtio_mem_sbm_test_sb_unplugged(struct virtio_mem *vm,
    static int virtio_mem_sbm_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_sbm_sb_state_bit_nr(vm, mb_id, 0);

    return find_next_zero_bit(vm->sbm.sb_states,
    bit + vm->nb_sb_per_mb, bit) - bit;
    --
    2.26.2
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