From a0e60b2033b30a6bb8479629001cf98e58e4079a Mon Sep 17 00:00:00 2001 From: David Gibson Date: Tue, 1 Nov 2005 17:28:10 +1100 Subject: [PATCH] powerpc: Merge bitops.h Here's a revised version. This re-introduces the set_bits() function from ppc64, which I removed because I thought it was unused (it exists on no other arch). In fact it is used in the powermac interrupt code (but not on pSeries). - We use LARXL/STCXL macros to generate the right (32 or 64 bit) instructions, similar to LDL/STL from ppc_asm.h, used in fpu.S - ppc32 previously used a full "sync" barrier at the end of test_and_*_bit(), whereas ppc64 used an "isync". The merged version uses "isync", since I believe that's sufficient. - The ppc64 versions of then minix_*() bitmap functions have changed semantics. Previously on ppc64, these functions were big-endian (that is bit 0 was the LSB in the first 64-bit, big-endian word). On ppc32 (and x86, for that matter, they were little-endian. As far as I can tell, the big-endian usage was simply wrong - I guess no-one ever tried to use minixfs on ppc64. - On ppc32 find_next_bit() and find_next_zero_bit() are no longer inline (they were already out-of-line on ppc64). - For ppc64, sched_find_first_bit() has moved from mmu_context.h to the merged bitops. What it was doing in mmu_context.h in the first place, I have no idea. - The fls() function is now implemented using the cntlzw instruction on ppc64, instead of generic_fls(), as it already was on ppc32. - For ARCH=ppc, this patch requires adding arch/powerpc/lib to the arch/ppc/Makefile. This in turn requires some changes to arch/powerpc/lib/Makefile which didn't correctly handle ARCH=ppc. Built and running on G5. Signed-off-by: David Gibson Signed-off-by: Paul Mackerras --- arch/powerpc/lib/Makefile | 9 +-- arch/powerpc/lib/bitops.c | 150 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 155 insertions(+), 4 deletions(-) create mode 100644 arch/powerpc/lib/bitops.c (limited to 'arch/powerpc/lib') diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile index dfb33915ad61..34f5c2e074c9 100644 --- a/arch/powerpc/lib/Makefile +++ b/arch/powerpc/lib/Makefile @@ -3,13 +3,14 @@ # ifeq ($(CONFIG_PPC_MERGE),y) -obj-y := string.o +obj-y := string.o strcase.o +obj-$(CONFIG_PPC32) += div64.o copy_32.o checksum_32.o endif -obj-y += strcase.o -obj-$(CONFIG_PPC32) += div64.o copy_32.o checksum_32.o +obj-y += bitops.o obj-$(CONFIG_PPC64) += checksum_64.o copypage_64.o copyuser_64.o \ - memcpy_64.o usercopy_64.o mem_64.o string.o + memcpy_64.o usercopy_64.o mem_64.o string.o \ + strcase.o obj-$(CONFIG_PPC_ISERIES) += e2a.o obj-$(CONFIG_XMON) += sstep.o diff --git a/arch/powerpc/lib/bitops.c b/arch/powerpc/lib/bitops.c new file mode 100644 index 000000000000..b67ce3004ebf --- /dev/null +++ b/arch/powerpc/lib/bitops.c @@ -0,0 +1,150 @@ +#include +#include +#include +#include + +/** + * find_next_bit - find the next set bit in a memory region + * @addr: The address to base the search on + * @offset: The bitnumber to start searching at + * @size: The maximum size to search + */ +unsigned long find_next_bit(const unsigned long *addr, unsigned long size, + unsigned long offset) +{ + const unsigned long *p = addr + BITOP_WORD(offset); + unsigned long result = offset & ~(BITS_PER_LONG-1); + unsigned long tmp; + + if (offset >= size) + return size; + size -= result; + offset %= BITS_PER_LONG; + if (offset) { + tmp = *(p++); + tmp &= (~0UL << offset); + if (size < BITS_PER_LONG) + goto found_first; + if (tmp) + goto found_middle; + size -= BITS_PER_LONG; + result += BITS_PER_LONG; + } + while (size & ~(BITS_PER_LONG-1)) { + if ((tmp = *(p++))) + goto found_middle; + result += BITS_PER_LONG; + size -= BITS_PER_LONG; + } + 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); + +/* + * This implementation of find_{first,next}_zero_bit was stolen from + * Linus' asm-alpha/bitops.h. + */ +unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, + unsigned long offset) +{ + const unsigned long *p = addr + BITOP_WORD(offset); + unsigned long result = offset & ~(BITS_PER_LONG-1); + unsigned long tmp; + + if (offset >= size) + return size; + size -= result; + offset %= BITS_PER_LONG; + if (offset) { + tmp = *(p++); + tmp |= ~0UL >> (BITS_PER_LONG - offset); + if (size < BITS_PER_LONG) + goto found_first; + if (~tmp) + goto found_middle; + size -= BITS_PER_LONG; + result += BITS_PER_LONG; + } + while (size & ~(BITS_PER_LONG-1)) { + if (~(tmp = *(p++))) + goto found_middle; + result += BITS_PER_LONG; + size -= BITS_PER_LONG; + } + 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); + +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); -- cgit v1.2.2