/* * Copyright (c) 2011 Broadcom Corporation * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include /* * crc8_populate_msb - fill crc table for given polynomial in reverse bit order. * * table: table to be filled. * polynomial: polynomial for which table is to be filled. */ void crc8_populate_msb(u8 table[CRC8_TABLE_SIZE], u8 polynomial) { int i, j; const u8 msbit = 0x80; u8 t = msbit; table[0] = 0; for (i = 1; i < CRC8_TABLE_SIZE; i *= 2) { t = (t << 1) ^ (t & msbit ? polynomial : 0); for (j = 0; j < i; j++) table[i+j] = table[j] ^ t; } } EXPORT_SYMBOL(crc8_populate_msb); /* * crc8_populate_lsb - fill crc table for given polynomial in regular bit order. * * table: table to be filled. * polynomial: polynomial for which table is to be filled. */ void crc8_populate_lsb(u8 table[CRC8_TABLE_SIZE], u8 polynomial) { int i, j; u8 t = 1; table[0] = 0; for (i = (CRC8_TABLE_SIZE >> 1); i; i >>= 1) { t = (t >> 1) ^ (t & 1 ? polynomial : 0); for (j = 0; j < CRC8_TABLE_SIZE; j += 2*i) table[i+j] = table[j] ^ t; } } EXPORT_SYMBOL(crc8_populate_lsb); /* * crc8 - calculate a crc8 over the given input data. * * table: crc table used for calculation. * pdata: pointer to data buffer. * nbytes: number of bytes in data buffer. * crc: previous returned crc8 value. */ u8 crc8(const u8 table[CRC8_TABLE_SIZE], u8 *pdata, size_t nbytes, u8 crc) { /* loop over the buffer data */ while (nbytes-- > 0) crc = table[(crc ^ *pdata++) & 0xff]; return crc; } EXPORT_SYMBOL(crc8); MODULE_DESCRIPTION("CRC8 (by Williams, Ross N.) function"); MODULE_AUTHOR("Broadcom Corporation"); MODULE_LICENSE("Dual BSD/GPL"); d55'/>
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authorJan Kara <jack@suse.cz>2016-08-10 17:22:44 +0200
committerDan Williams <dan.j.williams@intel.com>2016-12-26 20:29:24 -0800
commitc6dcf52c23d2d3fb5235cec42d7dd3f786b87d55 (patch)
tree7e63a6c0225a769e679b194f54b5723e4cfba385 /net
parente568df6b84ff05a22467503afc11bee7a6ba0700 (diff)
mm: Invalidate DAX radix tree entries only if appropriate
Currently invalidate_inode_pages2_range() and invalidate_mapping_pages() just delete all exceptional radix tree entries they find. For DAX this is not desirable as we track cache dirtiness in these entries and when they are evicted, we may not flush caches although it is necessary. This can for example manifest when we write to the same block both via mmap and via write(2) (to different offsets) and fsync(2) then does not properly flush CPU caches when modification via write(2) was the last one. Create appropriate DAX functions to handle invalidation of DAX entries for invalidate_inode_pages2_range() and invalidate_mapping_pages() and wire them up into the corresponding mm functions. Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'net')