diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/ppc64/kernel/bitops.c |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/ppc64/kernel/bitops.c')
-rw-r--r-- | arch/ppc64/kernel/bitops.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/arch/ppc64/kernel/bitops.c b/arch/ppc64/kernel/bitops.c new file mode 100644 index 00000000000..ae329e8b4ac --- /dev/null +++ b/arch/ppc64/kernel/bitops.c @@ -0,0 +1,147 @@ +/* + * These are too big to be inlined. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/bitops.h> +#include <asm/byteorder.h> + +unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, + unsigned long offset) +{ + const unsigned long *p = addr + (offset >> 6); + unsigned long result = offset & ~63UL; + unsigned long tmp; + + if (offset >= size) + return size; + size -= result; + offset &= 63UL; + if (offset) { + tmp = *(p++); + tmp |= ~0UL >> (64 - offset); + if (size < 64) + goto found_first; + if (~tmp) + goto found_middle; + size -= 64; + result += 64; + } + while (size & ~63UL) { + if (~(tmp = *(p++))) + goto found_middle; + result += 64; + size -= 64; + } + if (!size) + return result; + tmp = *p; + +found_first: + tmp |= ~0UL << size; + if (tmp == ~0UL) /* Are any bits zero? */ + return result + size; /* Nope. */ +found_middle: + return result + ffz(tmp); +} + +EXPORT_SYMBOL(find_next_zero_bit); + +unsigned long find_next_bit(const unsigned long *addr, unsigned long size, + unsigned long offset) +{ + const unsigned long *p = addr + (offset >> 6); + unsigned long result = offset & ~63UL; + unsigned long tmp; + + if (offset >= size) + return size; + size -= result; + offset &= 63UL; + if (offset) { + tmp = *(p++); + tmp &= (~0UL << offset); + if (size < 64) + goto found_first; + if (tmp) + goto found_middle; + size -= 64; + result += 64; + } + while (size & ~63UL) { + if ((tmp = *(p++))) + goto found_middle; + result += 64; + size -= 64; + } + if (!size) + return result; + tmp = *p; + +found_first: + tmp &= (~0UL >> (64 - size)); + if (tmp == 0UL) /* Are any bits set? */ + return result + size; /* Nope. */ +found_middle: + return result + __ffs(tmp); +} + +EXPORT_SYMBOL(find_next_bit); + +static inline unsigned int ext2_ilog2(unsigned int x) +{ + int lz; + + asm("cntlzw %0,%1": "=r"(lz):"r"(x)); + return 31 - lz; +} + +static inline unsigned int ext2_ffz(unsigned int x) +{ + u32 rc; + if ((x = ~x) == 0) + return 32; + rc = ext2_ilog2(x & -x); + return rc; +} + +unsigned long find_next_zero_le_bit(const unsigned long *addr, unsigned long size, + unsigned long offset) +{ + const unsigned int *p = ((const unsigned int *)addr) + (offset >> 5); + unsigned int result = offset & ~31; + unsigned int tmp; + + if (offset >= size) + return size; + size -= result; + offset &= 31; + if (offset) { + tmp = cpu_to_le32p(p++); + tmp |= ~0U >> (32 - offset); /* bug or feature ? */ + if (size < 32) + goto found_first; + if (tmp != ~0) + goto found_middle; + size -= 32; + result += 32; + } + while (size >= 32) { + if ((tmp = cpu_to_le32p(p++)) != ~0) + goto found_middle; + result += 32; + size -= 32; + } + if (!size) + return result; + tmp = cpu_to_le32p(p); +found_first: + tmp |= ~0 << size; + if (tmp == ~0) /* Are any bits zero? */ + return result + size; /* Nope. */ +found_middle: + return result + ext2_ffz(tmp); +} + +EXPORT_SYMBOL(find_next_zero_le_bit); |