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author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-27 15:14:26 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-27 15:14:26 -0700 |
commit | cea8f46c36c3f82860b038aa23a46e16757666ba (patch) | |
tree | e09dc37d2b6880d86dac09afbc0c686139d86df0 /arch/arm/include/asm/word-at-a-time.h | |
parent | c1e7179a38919f02dd950801529176b72f5e5a8a (diff) | |
parent | 91b006def384d8f07f9f324ab211fefe2b085c90 (diff) | |
download | op-kernel-dev-cea8f46c36c3f82860b038aa23a46e16757666ba.zip op-kernel-dev-cea8f46c36c3f82860b038aa23a46e16757666ba.tar.gz |
Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm
Pull ARM updates from Russell King:
"First ARM push of this merge window, post me coming back from holiday.
This is what has been in linux-next for the last few weeks. Not much
to say which isn't described by the commit summaries."
* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (32 commits)
ARM: 7463/1: topology: Update cpu_power according to DT information
ARM: 7462/1: topology: factorize the update of sibling masks
ARM: 7461/1: topology: Add arch_scale_freq_power function
ARM: 7456/1: ptrace: provide separate functions for tracing syscall {entry,exit}
ARM: 7455/1: audit: move syscall auditing until after ptrace SIGTRAP handling
ARM: 7454/1: entry: don't bother with syscall tracing on ret_from_fork path
ARM: 7453/1: audit: only allow syscall auditing for pure EABI userspace
ARM: 7452/1: delay: allow timer-based delay implementation to be selected
ARM: 7451/1: arch timer: implement read_current_timer and get_cycles
ARM: 7450/1: dcache: select DCACHE_WORD_ACCESS for little-endian ARMv6+ CPUs
ARM: 7449/1: use generic strnlen_user and strncpy_from_user functions
ARM: 7448/1: perf: remove arm_perf_pmu_ids global enumeration
ARM: 7447/1: rwlocks: remove unused branch labels from trylock routines
ARM: 7446/1: spinlock: use ticket algorithm for ARMv6+ locking implementation
ARM: 7445/1: mm: update CONTEXTIDR register to contain PID of current process
ARM: 7444/1: kernel: add arch-timer C3STOP feature
ARM: 7460/1: remove asm/locks.h
ARM: 7439/1: head.S: simplify initial page table mapping
ARM: 7437/1: zImage: Allow DTB command line concatenation with ATAG_CMDLINE
ARM: 7436/1: Do not map the vectors page as write-through on UP systems
...
Diffstat (limited to 'arch/arm/include/asm/word-at-a-time.h')
-rw-r--r-- | arch/arm/include/asm/word-at-a-time.h | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/arch/arm/include/asm/word-at-a-time.h b/arch/arm/include/asm/word-at-a-time.h new file mode 100644 index 0000000..4d52f92 --- /dev/null +++ b/arch/arm/include/asm/word-at-a-time.h @@ -0,0 +1,96 @@ +#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; +} + +#ifdef CONFIG_DCACHE_WORD_ACCESS + +#define zero_bytemask(mask) (mask) + +/* + * 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 .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" + " lsr %0, %0, %1\n" + " 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 */ + +#else /* __ARMEB__ */ +#include <asm-generic/word-at-a-time.h> +#endif + +#endif /* __ASM_ARM_WORD_AT_A_TIME_H */ |