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author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2017-03-14 17:07:33 +0300 |
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committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2017-03-14 17:07:33 +0300 |
commit | b70366e5d31788650b2a5cec5cd13ea80ac7e44a (patch) | |
tree | d972ffd190111d699200448494fda333d28b2486 /drivers/md/persistent-data/dm-bitset.c | |
parent | f42e181935d5e5670c87d31ae48063a495bbacae (diff) | |
parent | db6ccf23e8ba40fc2e8914ec9c0eb950df71d9fe (diff) | |
download | linux-b70366e5d31788650b2a5cec5cd13ea80ac7e44a.tar.xz |
Merge tag 'doc-4.11-images' of git://git.lwn.net/linux into drm-misc-next
Pointer for Markus's image conversion work.
We need this so we can merge all the pretty drm graphs for 4.12.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Diffstat (limited to 'drivers/md/persistent-data/dm-bitset.c')
-rw-r--r-- | drivers/md/persistent-data/dm-bitset.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/drivers/md/persistent-data/dm-bitset.c b/drivers/md/persistent-data/dm-bitset.c index 36f7cc2c7109..b7208d82e748 100644 --- a/drivers/md/persistent-data/dm-bitset.c +++ b/drivers/md/persistent-data/dm-bitset.c @@ -39,6 +39,48 @@ int dm_bitset_empty(struct dm_disk_bitset *info, dm_block_t *root) } EXPORT_SYMBOL_GPL(dm_bitset_empty); +struct packer_context { + bit_value_fn fn; + unsigned nr_bits; + void *context; +}; + +static int pack_bits(uint32_t index, void *value, void *context) +{ + int r; + struct packer_context *p = context; + unsigned bit, nr = min(64u, p->nr_bits - (index * 64)); + uint64_t word = 0; + bool bv; + + for (bit = 0; bit < nr; bit++) { + r = p->fn(index * 64 + bit, &bv, p->context); + if (r) + return r; + + if (bv) + set_bit(bit, (unsigned long *) &word); + else + clear_bit(bit, (unsigned long *) &word); + } + + *((__le64 *) value) = cpu_to_le64(word); + + return 0; +} + +int dm_bitset_new(struct dm_disk_bitset *info, dm_block_t *root, + uint32_t size, bit_value_fn fn, void *context) +{ + struct packer_context p; + p.fn = fn; + p.nr_bits = size; + p.context = context; + + return dm_array_new(&info->array_info, root, dm_div_up(size, 64), pack_bits, &p); +} +EXPORT_SYMBOL_GPL(dm_bitset_new); + int dm_bitset_resize(struct dm_disk_bitset *info, dm_block_t root, uint32_t old_nr_entries, uint32_t new_nr_entries, bool default_value, dm_block_t *new_root) @@ -168,4 +210,108 @@ int dm_bitset_test_bit(struct dm_disk_bitset *info, dm_block_t root, } EXPORT_SYMBOL_GPL(dm_bitset_test_bit); +static int cursor_next_array_entry(struct dm_bitset_cursor *c) +{ + int r; + __le64 *value; + + r = dm_array_cursor_next(&c->cursor); + if (r) + return r; + + dm_array_cursor_get_value(&c->cursor, (void **) &value); + c->array_index++; + c->bit_index = 0; + c->current_bits = le64_to_cpu(*value); + return 0; +} + +int dm_bitset_cursor_begin(struct dm_disk_bitset *info, + dm_block_t root, uint32_t nr_entries, + struct dm_bitset_cursor *c) +{ + int r; + __le64 *value; + + if (!nr_entries) + return -ENODATA; + + c->info = info; + c->entries_remaining = nr_entries; + + r = dm_array_cursor_begin(&info->array_info, root, &c->cursor); + if (r) + return r; + + dm_array_cursor_get_value(&c->cursor, (void **) &value); + c->array_index = 0; + c->bit_index = 0; + c->current_bits = le64_to_cpu(*value); + + return r; +} +EXPORT_SYMBOL_GPL(dm_bitset_cursor_begin); + +void dm_bitset_cursor_end(struct dm_bitset_cursor *c) +{ + return dm_array_cursor_end(&c->cursor); +} +EXPORT_SYMBOL_GPL(dm_bitset_cursor_end); + +int dm_bitset_cursor_next(struct dm_bitset_cursor *c) +{ + int r = 0; + + if (!c->entries_remaining) + return -ENODATA; + + c->entries_remaining--; + if (++c->bit_index > 63) + r = cursor_next_array_entry(c); + + return r; +} +EXPORT_SYMBOL_GPL(dm_bitset_cursor_next); + +int dm_bitset_cursor_skip(struct dm_bitset_cursor *c, uint32_t count) +{ + int r; + __le64 *value; + uint32_t nr_array_skip; + uint32_t remaining_in_word = 64 - c->bit_index; + + if (c->entries_remaining < count) + return -ENODATA; + + if (count < remaining_in_word) { + c->bit_index += count; + c->entries_remaining -= count; + return 0; + + } else { + c->entries_remaining -= remaining_in_word; + count -= remaining_in_word; + } + + nr_array_skip = (count / 64) + 1; + r = dm_array_cursor_skip(&c->cursor, nr_array_skip); + if (r) + return r; + + dm_array_cursor_get_value(&c->cursor, (void **) &value); + c->entries_remaining -= count; + c->array_index += nr_array_skip; + c->bit_index = count & 63; + c->current_bits = le64_to_cpu(*value); + + return 0; +} +EXPORT_SYMBOL_GPL(dm_bitset_cursor_skip); + +bool dm_bitset_cursor_get_value(struct dm_bitset_cursor *c) +{ + return test_bit(c->bit_index, (unsigned long *) &c->current_bits); +} +EXPORT_SYMBOL_GPL(dm_bitset_cursor_get_value); + /*----------------------------------------------------------------*/ |