Commit 41e6215c authored by David Hildenbrand's avatar David Hildenbrand Committed by Michael S. Tsirkin
Browse files

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: default avatarWei Yang <richard.weiyang@linux.alibaba.com>
Reviewed-by: default avatarPankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20201112133815.13332-7-david@redhat.com


Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 2a628511

drivers/virtio/virtio_mem.c

+15 −5
Original line number Diff line number Diff line
@@ -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;

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