[deliverable/linux.git] / arch / arm / include / asm / word-at-a-time.h

#ifndef __ASM_ARM_WORD_AT_A_TIME_H
#define __ASM_ARM_WORD_AT_A_TIME_H

#ifndef __ARMEB__

/*
 * Little-endian word-at-a-time zero byte handling.
 * Heavily based on the x86 algorithm.
 */
#include <linux/kernel.h>

struct word_at_a_time {
	const unsigned long one_bits, high_bits;
};

#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) }

static inline unsigned long has_zero(unsigned long a, unsigned long *bits,
				     const struct word_at_a_time *c)
{
	unsigned long mask = ((a - c->one_bits) & ~a) & c->high_bits;
	*bits = mask;
	return mask;
}

#define prep_zero_mask(a, bits, c) (bits)

static inline unsigned long create_zero_mask(unsigned long bits)
{
	bits = (bits - 1) & ~bits;
	return bits >> 7;
}

static inline unsigned long find_zero(unsigned long mask)
{
	unsigned long ret;

#if __LINUX_ARM_ARCH__ >= 5
	/* We have clz available. */
	ret = fls(mask) >> 3;
#else
	/* (000000 0000ff 00ffff ffffff) -> ( 1 1 2 3 ) */
	ret = (0x0ff0001 + mask) >> 23;
	/* Fix the 1 for 00 case */
	ret &= mask;
#endif

	return ret;
}

#define zero_bytemask(mask) (mask)

#else	/* __ARMEB__ */
#include <asm-generic/word-at-a-time.h>
#endif

#ifdef CONFIG_DCACHE_WORD_ACCESS

/*
 * Load an unaligned word from kernel space.
 *
 * In the (very unlikely) case of the word being a page-crosser
 * and the next page not being mapped, take the exception and
 * return zeroes in the non-existing part.
 */
static inline unsigned long load_unaligned_zeropad(const void *addr)
{
	unsigned long ret, offset;

	/* Load word from unaligned pointer addr */
	asm(
	"1:	ldr	%0, [%2]\n"
	"2:\n"
	"	.pushsection .text.fixup,\"ax\"\n"
	"	.align 2\n"
	"3:	and	%1, %2, #0x3\n"
	"	bic	%2, %2, #0x3\n"
	"	ldr	%0, [%2]\n"
	"	lsl	%1, %1, #0x3\n"
#ifndef __ARMEB__
	"	lsr	%0, %0, %1\n"
#else
	"	lsl	%0, %0, %1\n"
#endif
	"	b	2b\n"
	"	.popsection\n"
	"	.pushsection __ex_table,\"a\"\n"
	"	.align	3\n"
	"	.long	1b, 3b\n"
	"	.popsection"
	: "=&r" (ret), "=&r" (offset)
	: "r" (addr), "Qo" (*(unsigned long *)addr));

	return ret;
}

#endif	/* DCACHE_WORD_ACCESS */
#endif /* __ASM_ARM_WORD_AT_A_TIME_H */
Commit	Line	Data
8c56cc8b WD	1	#ifndef __ASM_ARM_WORD_AT_A_TIME_H
	2	#define __ASM_ARM_WORD_AT_A_TIME_H
	3
	4	#ifndef __ARMEB__
	5
	6	/*
	7	* Little-endian word-at-a-time zero byte handling.
	8	* Heavily based on the x86 algorithm.
	9	*/
	10	#include <linux/kernel.h>
	11
	12	struct word_at_a_time {
	13	const unsigned long one_bits, high_bits;
	14	};
	15
	16	#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) }
	17
	18	static inline unsigned long has_zero(unsigned long a, unsigned long *bits,
	19	const struct word_at_a_time *c)
	20	{
	21	unsigned long mask = ((a - c->one_bits) & ~a) & c->high_bits;
	22	*bits = mask;
	23	return mask;
	24	}
	25
	26	#define prep_zero_mask(a, bits, c) (bits)
	27
	28	static inline unsigned long create_zero_mask(unsigned long bits)
	29	{
	30	bits = (bits - 1) & ~bits;
	31	return bits >> 7;
	32	}
	33
	34	static inline unsigned long find_zero(unsigned long mask)
	35	{
	36	unsigned long ret;
	37
	38	#if __LINUX_ARM_ARCH__ >= 5
	39	/* We have clz available. */
	40	ret = fls(mask) >> 3;
	41	#else
	42	/* (000000 0000ff 00ffff ffffff) -> ( 1 1 2 3 ) */
	43	ret = (0x0ff0001 + mask) >> 23;
	44	/* Fix the 1 for 00 case */
	45	ret &= mask;
	46	#endif
	47
	48	return ret;
	49	}
	50
b9a50f74 WD	51	#define zero_bytemask(mask) (mask)
b9a50f74 WD	52
cb601185 WD	53	#else /* __ARMEB__ */
	54	#include <asm-generic/word-at-a-time.h>
	55	#endif
	56
	57	#ifdef CONFIG_DCACHE_WORD_ACCESS
	58
b9a50f74 WD	59	/*
	60	* Load an unaligned word from kernel space.
	61	*
	62	* In the (very unlikely) case of the word being a page-crosser
	63	* and the next page not being mapped, take the exception and
	64	* return zeroes in the non-existing part.
	65	*/
	66	static inline unsigned long load_unaligned_zeropad(const void *addr)
	67	{
	68	unsigned long ret, offset;
	69
	70	/* Load word from unaligned pointer addr */
	71	asm(
	72	"1: ldr %0, [%2]\n"
	73	"2:\n"
c4a84ae3	74	" .pushsection .text.fixup,\"ax\"\n"
b9a50f74 WD	75	" .align 2\n"
	76	"3: and %1, %2, #0x3\n"
	77	" bic %2, %2, #0x3\n"
	78	" ldr %0, [%2]\n"
	79	" lsl %1, %1, #0x3\n"
cb601185	80	#ifndef __ARMEB__
b9a50f74	81	" lsr %0, %0, %1\n"
cb601185 WD	82	#else
	83	" lsl %0, %0, %1\n"
	84	#endif
b9a50f74 WD	85	" b 2b\n"
	86	" .popsection\n"
	87	" .pushsection __ex_table,\"a\"\n"
	88	" .align 3\n"
	89	" .long 1b, 3b\n"
	90	" .popsection"
	91	: "=&r" (ret), "=&r" (offset)
	92	: "r" (addr), "Qo" ((unsigned long )addr));
	93
	94	return ret;
	95	}
	96
b9a50f74	97	#endif /* DCACHE_WORD_ACCESS */
8c56cc8b	98	#endif /* __ASM_ARM_WORD_AT_A_TIME_H */