Eric Lee / smarc-ti-linux-kernel | Embedian Git Server

Commit 7150962d637cf38617924f7f72ea00612283eb89

Authored by Arend van Spriel 2011-05-31 17:22:15 +0800

Committed by John W. Linville 2011-06-04 03:01:06 +0800

lib: crc8: add new library module providing crc8 algorithm

The brcm80211 driver in staging tree uses a crc8 function. Based on
feedback from John Linville to move this to lib directory, the linux
source has been searched. Although there is currently only one other
kernel driver using this algorithm (ie. drivers/ssb) we are providing
this as a library function for others to use.

Cc: linux-kernel@vger.kernel.org
Cc: linux-wireless@vger.kernel.org
Cc: Dan Carpenter <error27@gmail.com>
Cc: George Spelvin <linux@horizon.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Reviewed-by: Henry Ptasinski <henryp@broadcom.com>
Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Reviewed-by: "Franky (Zhenhui) Lin" <frankyl@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Showing 4 changed files with 195 additions and 0 deletions Inline Diff

include/linux/crc8.h
lib/Kconfig
lib/Makefile
lib/crc8.c

include/linux/crc8.h

Diff comments View file @ 7150962

File was created	1	/*
	2	* Copyright (c) 2011 Broadcom Corporation
	3	*
	4	* Permission to use, copy, modify, and/or distribute this software for any
	5	* purpose with or without fee is hereby granted, provided that the above
	6	* copyright notice and this permission notice appear in all copies.
	7	*
	8	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	9	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	10	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
	11	* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	12	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
	13	* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
	14	* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	15	*/
	16	#ifndef __CRC8_H_
	17	#define __CRC8_H_
	18
	19	#include <linux/types.h>
	20
	21	/* see usage of this value in crc8() description */
	22	#define CRC8_INIT_VALUE 0xFF
	23
	24	/*
	25	* Return value of crc8() indicating valid message+crc. This is true
	26	* if a CRC is inverted before transmission. The CRC computed over the
	27	* whole received bitstream is _table[x], where x is the bit pattern
	28	* of the modification (almost always 0xff).
	29	*/
	30	#define CRC8_GOOD_VALUE(_table) (_table[0xFF])
	31
	32	/* required table size for crc8 algorithm */
	33	#define CRC8_TABLE_SIZE 256
	34
	35	/* helper macro assuring right table size is used */
	36	#define DECLARE_CRC8_TABLE(_table) \
	37	static u8 _table[CRC8_TABLE_SIZE]
	38
	39	/**
	40	* crc8_populate_lsb - fill crc table for given polynomial in regular bit order.
	41	*
	42	* @table: table to be filled.
	43	* @polynomial: polynomial for which table is to be filled.
	44	*
	45	* This function fills the provided table according the polynomial provided for
	46	* regular bit order (lsb first). Polynomials in CRC algorithms are typically
	47	* represented as shown below.
	48	*
	49	* poly = x^8 + x^7 + x^6 + x^4 + x^2 + 1
	50	*
	51	* For lsb first direction x^7 maps to the lsb. So the polynomial is as below.
	52	*
	53	* - lsb first: poly = 10101011(1) = 0xAB
	54	*/
	55	void crc8_populate_lsb(u8 table[CRC8_TABLE_SIZE], u8 polynomial);
	56
	57	/**
	58	* crc8_populate_msb - fill crc table for given polynomial in reverse bit order.
	59	*
	60	* @table: table to be filled.
	61	* @polynomial: polynomial for which table is to be filled.
	62	*
	63	* This function fills the provided table according the polynomial provided for
	64	* reverse bit order (msb first). Polynomials in CRC algorithms are typically
	65	* represented as shown below.
	66	*
	67	* poly = x^8 + x^7 + x^6 + x^4 + x^2 + 1
	68	*
	69	* For msb first direction x^7 maps to the msb. So the polynomial is as below.
	70	*
	71	* - msb first: poly = (1)11010101 = 0xD5
	72	*/
	73	void crc8_populate_msb(u8 table[CRC8_TABLE_SIZE], u8 polynomial);
	74
	75	/**
	76	* crc8() - calculate a crc8 over the given input data.
	77	*
	78	* @table: crc table used for calculation.
	79	* @pdata: pointer to data buffer.
	80	* @nbytes: number of bytes in data buffer.
	81	* @crc: previous returned crc8 value.
	82	*
	83	* The CRC8 is calculated using the polynomial given in crc8_populate_msb()
	84	* or crc8_populate_lsb().
	85	*
	86	* The caller provides the initial value (either %CRC8_INIT_VALUE
	87	* or the previous returned value) to allow for processing of
	88	* discontiguous blocks of data. When generating the CRC the
	89	* caller is responsible for complementing the final return value
	90	* and inserting it into the byte stream. When validating a byte
	91	* stream (including CRC8), a final return value of %CRC8_GOOD_VALUE
	92	* indicates the byte stream data can be considered valid.
	93	*
	94	* Reference:
	95	* "A Painless Guide to CRC Error Detection Algorithms", ver 3, Aug 1993
	96	* Williams, Ross N., ross<at>ross.net
	97	* (see URL http://www.ross.net/crc/download/crc_v3.txt).
	98	*/
	99	u8 crc8(const u8 table[CRC8_TABLE_SIZE], u8 *pdata, size_t nbytes, u8 crc);
	100
	101	#endif /* __CRC8_H_ */
	102

lib/Kconfig

Diff comments View file @ 7150962

 #
 # Library configuration
 #
 config BINARY_PRINTF
 	def_bool n
 menu "Library routines"
 config RAID6_PQ
 	tristate
 config BITREVERSE
 	tristate
 config RATIONAL
 	boolean
 config GENERIC_FIND_FIRST_BIT
 	bool
 config GENERIC_FIND_NEXT_BIT
 	bool
 config GENERIC_FIND_BIT_LE
 	bool
 config GENERIC_FIND_LAST_BIT
 	bool
 	default y
 config CRC_CCITT
 	tristate "CRC-CCITT functions"
 	help
 	  This option is provided for the case where no in-kernel-tree
 	  modules require CRC-CCITT functions, but a module built outside
 	  the kernel tree does. Such modules that use library CRC-CCITT
 	  functions require M here.
 config CRC16
 	tristate "CRC16 functions"
 	help
 	  This option is provided for the case where no in-kernel-tree
 	  modules require CRC16 functions, but a module built outside
 	  the kernel tree does. Such modules that use library CRC16
 	  functions require M here.
 config CRC_T10DIF
 	tristate "CRC calculation for the T10 Data Integrity Field"
 	help
 	  This option is only needed if a module that's not in the
 	  kernel tree needs to calculate CRC checks for use with the
 	  SCSI data integrity subsystem.
 config CRC_ITU_T
 	tristate "CRC ITU-T V.41 functions"
 	help
 	  This option is provided for the case where no in-kernel-tree
 	  modules require CRC ITU-T V.41 functions, but a module built outside
 	  the kernel tree does. Such modules that use library CRC ITU-T V.41
 	  functions require M here.
 config CRC32
 	tristate "CRC32 functions"
 	default y
 	select BITREVERSE
 	help
 	  This option is provided for the case where no in-kernel-tree
 	  modules require CRC32 functions, but a module built outside the
 	  kernel tree does. Such modules that use library CRC32 functions
 	  require M here.
 config CRC7
 	tristate "CRC7 functions"
 	help
 	  This option is provided for the case where no in-kernel-tree
 	  modules require CRC7 functions, but a module built outside
 	  the kernel tree does. Such modules that use library CRC7
 	  functions require M here.
 config LIBCRC32C
 	tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check"
 	select CRYPTO
 	select CRYPTO_CRC32C
 	help
 	  This option is provided for the case where no in-kernel-tree
 	  modules require CRC32c functions, but a module built outside the
 	  kernel tree does. Such modules that use library CRC32c functions
 	  require M here.  See Castagnoli93.
 	  Module will be libcrc32c.
+config CRC8
+	tristate "CRC8 function"
+	help
+	  This option provides CRC8 function. Drivers may select this
+	  when they need to do cyclic redundancy check according CRC8
+	  algorithm. Module will be called crc8.
 config AUDIT_GENERIC
 	bool
 	depends on AUDIT && !AUDIT_ARCH
 	default y
 #
 # compression support is select'ed if needed
 #
 config ZLIB_INFLATE
 	tristate
 config ZLIB_DEFLATE
 	tristate
 config LZO_COMPRESS
 	tristate
 config LZO_DECOMPRESS
 	tristate
 source "lib/xz/Kconfig"
 #
 # These all provide a common interface (hence the apparent duplication with
 # ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.)
 #
 config DECOMPRESS_GZIP
 	select ZLIB_INFLATE
 	tristate
 config DECOMPRESS_BZIP2
 	tristate
 config DECOMPRESS_LZMA
 	tristate
 config DECOMPRESS_XZ
 	select XZ_DEC
 	tristate
 config DECOMPRESS_LZO
 	select LZO_DECOMPRESS
 	tristate
 #
 # Generic allocator support is selected if needed
 #
 config GENERIC_ALLOCATOR
 	boolean
 #
 # reed solomon support is select'ed if needed
 #
 config REED_SOLOMON
 	tristate
 config REED_SOLOMON_ENC8
 	boolean
 config REED_SOLOMON_DEC8
 	boolean
 config REED_SOLOMON_ENC16
 	boolean
 config REED_SOLOMON_DEC16
 	boolean
 #
 # BCH support is selected if needed
 #
 config BCH
 	tristate
 config BCH_CONST_PARAMS
 	boolean
 	help
 	  Drivers may select this option to force specific constant
 	  values for parameters 'm' (Galois field order) and 't'
 	  (error correction capability). Those specific values must
 	  be set by declaring default values for symbols BCH_CONST_M
 	  and BCH_CONST_T.
 	  Doing so will enable extra compiler optimizations,
 	  improving encoding and decoding performance up to 2x for
 	  usual (m,t) values (typically such that m*t < 200).
 	  When this option is selected, the BCH library supports
 	  only a single (m,t) configuration. This is mainly useful
 	  for NAND flash board drivers requiring known, fixed BCH
 	  parameters.
 config BCH_CONST_M
 	int
 	range 5 15
 	help
 	  Constant value for Galois field order 'm'. If 'k' is the
 	  number of data bits to protect, 'm' should be chosen such
 	  that (k + m*t) <= 2**m - 1.
 	  Drivers should declare a default value for this symbol if
 	  they select option BCH_CONST_PARAMS.
 config BCH_CONST_T
 	int
 	help
 	  Constant value for error correction capability in bits 't'.
 	  Drivers should declare a default value for this symbol if
 	  they select option BCH_CONST_PARAMS.
 #
 # Textsearch support is select'ed if needed
 #
 config TEXTSEARCH
 	boolean
 config TEXTSEARCH_KMP
 	tristate
 config TEXTSEARCH_BM
 	tristate
 config TEXTSEARCH_FSM
 	tristate
 config BTREE
 	boolean
 config HAS_IOMEM
 	boolean
 	depends on !NO_IOMEM
 	default y
 config HAS_IOPORT
 	boolean
 	depends on HAS_IOMEM && !NO_IOPORT
 	default y
 config HAS_DMA
 	boolean
 	depends on !NO_DMA
 	default y
 config CHECK_SIGNATURE
 	bool
 config CPUMASK_OFFSTACK
 	bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS
 	help
 	  Use dynamic allocation for cpumask_var_t, instead of putting
 	  them on the stack.  This is a bit more expensive, but avoids
 	  stack overflow.
 config DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
        bool "Disable obsolete cpumask functions" if DEBUG_PER_CPU_MAPS
        depends on EXPERIMENTAL && BROKEN
 config CPU_RMAP
 	bool
 	depends on SMP
 #
 # Netlink attribute parsing support is select'ed if needed
 #
 config NLATTR
 	bool
 #
 # Generic 64-bit atomic support is selected if needed
 #
 config GENERIC_ATOMIC64
        bool
 config LRU_CACHE
 	tristate
 config AVERAGE
 	bool "Averaging functions"
 	help
 	  This option is provided for the case where no in-kernel-tree
 	  modules require averaging functions, but a module built outside
 	  the kernel tree does. Such modules that use library averaging
 	  functions require Y here.
 	  If unsure, say N.
 endmenu

lib/Makefile

Diff comments View file @ 7150962

 #
 # Makefile for some libs needed in the kernel.
 #
 ifdef CONFIG_FUNCTION_TRACER
 ORIG_CFLAGS := $(KBUILD_CFLAGS)
 KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS))
 endif
 lib-y := ctype.o string.o vsprintf.o cmdline.o \
 	 rbtree.o radix-tree.o dump_stack.o timerqueue.o\
 	 idr.o int_sqrt.o extable.o prio_tree.o \
 	 sha1.o irq_regs.o reciprocal_div.o argv_split.o \
 	 proportions.o prio_heap.o ratelimit.o show_mem.o \
 	 is_single_threaded.o plist.o decompress.o
 lib-$(CONFIG_MMU) += ioremap.o
 lib-$(CONFIG_SMP) += cpumask.o
 lib-y	+= kobject.o kref.o klist.o
 obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
 	 bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \
 	 string_helpers.o gcd.o lcm.o list_sort.o uuid.o flex_array.o \
 	 bsearch.o
 obj-y += kstrtox.o
 obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o
 ifeq ($(CONFIG_DEBUG_KOBJECT),y)
 CFLAGS_kobject.o += -DDEBUG
 CFLAGS_kobject_uevent.o += -DDEBUG
 endif
 lib-$(CONFIG_HOTPLUG) += kobject_uevent.o
 obj-$(CONFIG_GENERIC_IOMAP) += iomap.o
 obj-$(CONFIG_HAS_IOMEM) += iomap_copy.o devres.o
 obj-$(CONFIG_CHECK_SIGNATURE) += check_signature.o
 obj-$(CONFIG_DEBUG_LOCKING_API_SELFTESTS) += locking-selftest.o
 obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o
 lib-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
 lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o
 lib-$(CONFIG_GENERIC_FIND_FIRST_BIT) += find_next_bit.o
 lib-$(CONFIG_GENERIC_FIND_NEXT_BIT) += find_next_bit.o
 lib-$(CONFIG_GENERIC_FIND_BIT_LE) += find_next_bit.o
 obj-$(CONFIG_GENERIC_FIND_LAST_BIT) += find_last_bit.o
 CFLAGS_hweight.o = $(subst $(quote),,$(CONFIG_ARCH_HWEIGHT_CFLAGS))
 obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o
 obj-$(CONFIG_BTREE) += btree.o
 obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o
 obj-$(CONFIG_DEBUG_LIST) += list_debug.o
 obj-$(CONFIG_DEBUG_OBJECTS) += debugobjects.o
 ifneq ($(CONFIG_HAVE_DEC_LOCK),y)
   lib-y += dec_and_lock.o
 endif
 obj-$(CONFIG_BITREVERSE) += bitrev.o
 obj-$(CONFIG_RATIONAL)	+= rational.o
 obj-$(CONFIG_CRC_CCITT)	+= crc-ccitt.o
 obj-$(CONFIG_CRC16)	+= crc16.o
 obj-$(CONFIG_CRC_T10DIF)+= crc-t10dif.o
 obj-$(CONFIG_CRC_ITU_T)	+= crc-itu-t.o
 obj-$(CONFIG_CRC32)	+= crc32.o
 obj-$(CONFIG_CRC7)	+= crc7.o
 obj-$(CONFIG_LIBCRC32C)	+= libcrc32c.o
+obj-$(CONFIG_CRC8)	+= crc8.o
 obj-$(CONFIG_GENERIC_ALLOCATOR) += genalloc.o
 obj-$(CONFIG_ZLIB_INFLATE) += zlib_inflate/
 obj-$(CONFIG_ZLIB_DEFLATE) += zlib_deflate/
 obj-$(CONFIG_REED_SOLOMON) += reed_solomon/
 obj-$(CONFIG_BCH) += bch.o
 obj-$(CONFIG_LZO_COMPRESS) += lzo/
 obj-$(CONFIG_LZO_DECOMPRESS) += lzo/
 obj-$(CONFIG_XZ_DEC) += xz/
 obj-$(CONFIG_RAID6_PQ) += raid6/
 lib-$(CONFIG_DECOMPRESS_GZIP) += decompress_inflate.o
 lib-$(CONFIG_DECOMPRESS_BZIP2) += decompress_bunzip2.o
 lib-$(CONFIG_DECOMPRESS_LZMA) += decompress_unlzma.o
 lib-$(CONFIG_DECOMPRESS_XZ) += decompress_unxz.o
 lib-$(CONFIG_DECOMPRESS_LZO) += decompress_unlzo.o
 obj-$(CONFIG_TEXTSEARCH) += textsearch.o
 obj-$(CONFIG_TEXTSEARCH_KMP) += ts_kmp.o
 obj-$(CONFIG_TEXTSEARCH_BM) += ts_bm.o
 obj-$(CONFIG_TEXTSEARCH_FSM) += ts_fsm.o
 obj-$(CONFIG_SMP) += percpu_counter.o
 obj-$(CONFIG_AUDIT_GENERIC) += audit.o
 obj-$(CONFIG_SWIOTLB) += swiotlb.o
 obj-$(CONFIG_IOMMU_HELPER) += iommu-helper.o
 obj-$(CONFIG_FAULT_INJECTION) += fault-inject.o
 obj-$(CONFIG_CPU_NOTIFIER_ERROR_INJECT) += cpu-notifier-error-inject.o
 lib-$(CONFIG_GENERIC_BUG) += bug.o
 obj-$(CONFIG_HAVE_ARCH_TRACEHOOK) += syscall.o
 obj-$(CONFIG_DYNAMIC_DEBUG) += dynamic_debug.o
 obj-$(CONFIG_NLATTR) += nlattr.o
 obj-$(CONFIG_LRU_CACHE) += lru_cache.o
 obj-$(CONFIG_DMA_API_DEBUG) += dma-debug.o
 obj-$(CONFIG_GENERIC_CSUM) += checksum.o
 obj-$(CONFIG_GENERIC_ATOMIC64) += atomic64.o
 obj-$(CONFIG_ATOMIC64_SELFTEST) += atomic64_test.o
 obj-$(CONFIG_AVERAGE) += average.o
 obj-$(CONFIG_CPU_RMAP) += cpu_rmap.o
 hostprogs-y	:= gen_crc32table
 clean-files	:= crc32table.h
 $(obj)/crc32.o: $(obj)/crc32table.h
 quiet_cmd_crc32 = GEN     $@
       cmd_crc32 = $< > $@
 $(obj)/crc32table.h: $(obj)/gen_crc32table
 	$(call cmd,crc32)

lib/crc8.c

Diff comments View file @ 7150962

File was created	1	/*
	2	* Copyright (c) 2011 Broadcom Corporation
	3	*
	4	* Permission to use, copy, modify, and/or distribute this software for any
	5	* purpose with or without fee is hereby granted, provided that the above
	6	* copyright notice and this permission notice appear in all copies.
	7	*
	8	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	9	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	10	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
	11	* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	12	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
	13	* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
	14	* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	15	*/
	16
	17	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	18
	19	#include <linux/module.h>
	20	#include <linux/crc8.h>
	21	#include <linux/printk.h>
	22
	23	/*
	24	* crc8_populate_msb - fill crc table for given polynomial in reverse bit order.
	25	*
	26	* table: table to be filled.
	27	* polynomial: polynomial for which table is to be filled.
	28	*/
	29	void crc8_populate_msb(u8 table[CRC8_TABLE_SIZE], u8 polynomial)
	30	{
	31	int i, j;
	32	const u8 msbit = 0x80;
	33	u8 t = msbit;
	34
	35	table[0] = 0;
	36
	37	for (i = 1; i < CRC8_TABLE_SIZE; i *= 2) {
	38	t = (t << 1) ^ (t & msbit ? polynomial : 0);
	39	for (j = 0; j < i; j++)
	40	table[i+j] = table[j] ^ t;
	41	}
	42	}
	43	EXPORT_SYMBOL(crc8_populate_msb);
	44
	45	/*
	46	* crc8_populate_lsb - fill crc table for given polynomial in regular bit order.
	47	*
	48	* table: table to be filled.
	49	* polynomial: polynomial for which table is to be filled.
	50	*/
	51	void crc8_populate_lsb(u8 table[CRC8_TABLE_SIZE], u8 polynomial)
	52	{
	53	int i, j;
	54	u8 t = 1;
	55
	56	table[0] = 0;
	57
	58	for (i = (CRC8_TABLE_SIZE >> 1); i; i >>= 1) {
	59	t = (t >> 1) ^ (t & 1 ? polynomial : 0);
	60	for (j = 0; j < CRC8_TABLE_SIZE; j += 2*i)
	61	table[i+j] = table[j] ^ t;
	62	}
	63	}
	64	EXPORT_SYMBOL(crc8_populate_lsb);
	65
	66	/*
	67	* crc8 - calculate a crc8 over the given input data.
	68	*
	69	* table: crc table used for calculation.
	70	* pdata: pointer to data buffer.
	71	* nbytes: number of bytes in data buffer.
	72	* crc: previous returned crc8 value.
	73	*/
	74	u8 crc8(const u8 table[CRC8_TABLE_SIZE], u8 *pdata, size_t nbytes, u8 crc)
	75	{
	76	/* loop over the buffer data */
	77	while (nbytes-- > 0)
	78	crc = table[(crc ^ *pdata++) & 0xff];
	79
	80	return crc;
	81	}
	82	EXPORT_SYMBOL(crc8);
	83
	84	MODULE_DESCRIPTION("CRC8 (by Williams, Ross N.) function");
	85	MODULE_AUTHOR("Broadcom Corporation");
	86	MODULE_LICENSE("Dual BSD/GPL");
	87