forked from Minki/linux
f782ddf297
With the __ilog2() function as defined in
arch/powerpc/include/asm/bitops.h, GCC will not optimise the code
in case of constant parameter.
The generic ilog2() function in include/linux/log2.h is written
to handle the case of the constant parameter.
This patch discards the three __ilog2() functions and
defines __ilog2() as ilog2()
For non constant calls, the generated code is doing the same:
int test__ilog2(unsigned long x)
{
return __ilog2(x);
}
int test__ilog2_u32(u32 n)
{
return __ilog2_u32(n);
}
int test__ilog2_u64(u64 n)
{
return __ilog2_u64(n);
}
On PPC32 before the patch:
00000000 <test__ilog2>:
0: 7c 63 00 34 cntlzw r3,r3
4: 20 63 00 1f subfic r3,r3,31
8: 4e 80 00 20 blr
0000000c <test__ilog2_u32>:
c: 7c 63 00 34 cntlzw r3,r3
10: 20 63 00 1f subfic r3,r3,31
14: 4e 80 00 20 blr
On PPC32 after the patch:
00000000 <test__ilog2>:
0: 7c 63 00 34 cntlzw r3,r3
4: 20 63 00 1f subfic r3,r3,31
8: 4e 80 00 20 blr
0000000c <test__ilog2_u32>:
c: 7c 63 00 34 cntlzw r3,r3
10: 20 63 00 1f subfic r3,r3,31
14: 4e 80 00 20 blr
On PPC64 before the patch:
0000000000000000 <.test__ilog2>:
0: 7c 63 00 74 cntlzd r3,r3
4: 20 63 00 3f subfic r3,r3,63
8: 7c 63 07 b4 extsw r3,r3
c: 4e 80 00 20 blr
0000000000000010 <.test__ilog2_u32>:
10: 7c 63 00 34 cntlzw r3,r3
14: 20 63 00 1f subfic r3,r3,31
18: 7c 63 07 b4 extsw r3,r3
1c: 4e 80 00 20 blr
0000000000000020 <.test__ilog2_u64>:
20: 7c 63 00 74 cntlzd r3,r3
24: 20 63 00 3f subfic r3,r3,63
28: 7c 63 07 b4 extsw r3,r3
2c: 4e 80 00 20 blr
On PPC64 after the patch:
0000000000000000 <.test__ilog2>:
0: 7c 63 00 74 cntlzd r3,r3
4: 20 63 00 3f subfic r3,r3,63
8: 7c 63 07 b4 extsw r3,r3
c: 4e 80 00 20 blr
0000000000000010 <.test__ilog2_u32>:
10: 7c 63 00 34 cntlzw r3,r3
14: 20 63 00 1f subfic r3,r3,31
18: 7c 63 07 b4 extsw r3,r3
1c: 4e 80 00 20 blr
0000000000000020 <.test__ilog2_u64>:
20: 7c 63 00 74 cntlzd r3,r3
24: 20 63 00 3f subfic r3,r3,63
28: 7c 63 07 b4 extsw r3,r3
2c: 4e 80 00 20 blr
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
257 lines
7.3 KiB
C
257 lines
7.3 KiB
C
/*
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* PowerPC atomic bit operations.
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*
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* Merged version by David Gibson <david@gibson.dropbear.id.au>.
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* Based on ppc64 versions by: Dave Engebretsen, Todd Inglett, Don
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* Reed, Pat McCarthy, Peter Bergner, Anton Blanchard. They
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* originally took it from the ppc32 code.
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*
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* Within a word, bits are numbered LSB first. Lot's of places make
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* this assumption by directly testing bits with (val & (1<<nr)).
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* This can cause confusion for large (> 1 word) bitmaps on a
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* big-endian system because, unlike little endian, the number of each
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* bit depends on the word size.
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*
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* The bitop functions are defined to work on unsigned longs, so for a
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* ppc64 system the bits end up numbered:
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* |63..............0|127............64|191...........128|255...........192|
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* and on ppc32:
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* |31.....0|63....32|95....64|127...96|159..128|191..160|223..192|255..224|
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*
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* There are a few little-endian macros used mostly for filesystem
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* bitmaps, these work on similar bit arrays layouts, but
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* byte-oriented:
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* |7...0|15...8|23...16|31...24|39...32|47...40|55...48|63...56|
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*
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* The main difference is that bit 3-5 (64b) or 3-4 (32b) in the bit
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* number field needs to be reversed compared to the big-endian bit
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* fields. This can be achieved by XOR with 0x38 (64b) or 0x18 (32b).
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _ASM_POWERPC_BITOPS_H
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#define _ASM_POWERPC_BITOPS_H
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#ifdef __KERNEL__
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#ifndef _LINUX_BITOPS_H
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#error only <linux/bitops.h> can be included directly
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#endif
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#include <linux/compiler.h>
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#include <asm/asm-compat.h>
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#include <asm/synch.h>
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/* PPC bit number conversion */
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#define PPC_BITLSHIFT(be) (BITS_PER_LONG - 1 - (be))
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#define PPC_BIT(bit) (1UL << PPC_BITLSHIFT(bit))
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#define PPC_BITMASK(bs, be) ((PPC_BIT(bs) - PPC_BIT(be)) | PPC_BIT(bs))
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/* Put a PPC bit into a "normal" bit position */
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#define PPC_BITEXTRACT(bits, ppc_bit, dst_bit) \
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((((bits) >> PPC_BITLSHIFT(ppc_bit)) & 1) << (dst_bit))
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#define PPC_BITLSHIFT32(be) (32 - 1 - (be))
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#define PPC_BIT32(bit) (1UL << PPC_BITLSHIFT32(bit))
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#define PPC_BITMASK32(bs, be) ((PPC_BIT32(bs) - PPC_BIT32(be))|PPC_BIT32(bs))
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#define PPC_BITLSHIFT8(be) (8 - 1 - (be))
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#define PPC_BIT8(bit) (1UL << PPC_BITLSHIFT8(bit))
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#define PPC_BITMASK8(bs, be) ((PPC_BIT8(bs) - PPC_BIT8(be))|PPC_BIT8(bs))
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#include <asm/barrier.h>
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/* Macro for generating the ***_bits() functions */
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#define DEFINE_BITOP(fn, op, prefix) \
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static __inline__ void fn(unsigned long mask, \
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volatile unsigned long *_p) \
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{ \
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unsigned long old; \
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unsigned long *p = (unsigned long *)_p; \
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__asm__ __volatile__ ( \
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prefix \
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"1:" PPC_LLARX(%0,0,%3,0) "\n" \
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stringify_in_c(op) "%0,%0,%2\n" \
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PPC405_ERR77(0,%3) \
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PPC_STLCX "%0,0,%3\n" \
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"bne- 1b\n" \
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: "=&r" (old), "+m" (*p) \
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: "r" (mask), "r" (p) \
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: "cc", "memory"); \
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}
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DEFINE_BITOP(set_bits, or, "")
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DEFINE_BITOP(clear_bits, andc, "")
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DEFINE_BITOP(clear_bits_unlock, andc, PPC_RELEASE_BARRIER)
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DEFINE_BITOP(change_bits, xor, "")
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static __inline__ void set_bit(int nr, volatile unsigned long *addr)
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{
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set_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
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}
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static __inline__ void clear_bit(int nr, volatile unsigned long *addr)
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{
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clear_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
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}
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static __inline__ void clear_bit_unlock(int nr, volatile unsigned long *addr)
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{
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clear_bits_unlock(BIT_MASK(nr), addr + BIT_WORD(nr));
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}
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static __inline__ void change_bit(int nr, volatile unsigned long *addr)
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{
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change_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
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}
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/* Like DEFINE_BITOP(), with changes to the arguments to 'op' and the output
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* operands. */
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#define DEFINE_TESTOP(fn, op, prefix, postfix, eh) \
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static __inline__ unsigned long fn( \
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unsigned long mask, \
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volatile unsigned long *_p) \
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{ \
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unsigned long old, t; \
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unsigned long *p = (unsigned long *)_p; \
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__asm__ __volatile__ ( \
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prefix \
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"1:" PPC_LLARX(%0,0,%3,eh) "\n" \
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stringify_in_c(op) "%1,%0,%2\n" \
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PPC405_ERR77(0,%3) \
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PPC_STLCX "%1,0,%3\n" \
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"bne- 1b\n" \
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postfix \
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: "=&r" (old), "=&r" (t) \
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: "r" (mask), "r" (p) \
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: "cc", "memory"); \
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return (old & mask); \
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}
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DEFINE_TESTOP(test_and_set_bits, or, PPC_ATOMIC_ENTRY_BARRIER,
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PPC_ATOMIC_EXIT_BARRIER, 0)
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DEFINE_TESTOP(test_and_set_bits_lock, or, "",
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PPC_ACQUIRE_BARRIER, 1)
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DEFINE_TESTOP(test_and_clear_bits, andc, PPC_ATOMIC_ENTRY_BARRIER,
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PPC_ATOMIC_EXIT_BARRIER, 0)
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DEFINE_TESTOP(test_and_change_bits, xor, PPC_ATOMIC_ENTRY_BARRIER,
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PPC_ATOMIC_EXIT_BARRIER, 0)
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static __inline__ int test_and_set_bit(unsigned long nr,
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volatile unsigned long *addr)
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{
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return test_and_set_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
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}
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static __inline__ int test_and_set_bit_lock(unsigned long nr,
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volatile unsigned long *addr)
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{
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return test_and_set_bits_lock(BIT_MASK(nr),
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addr + BIT_WORD(nr)) != 0;
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}
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static __inline__ int test_and_clear_bit(unsigned long nr,
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volatile unsigned long *addr)
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{
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return test_and_clear_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
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}
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static __inline__ int test_and_change_bit(unsigned long nr,
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volatile unsigned long *addr)
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{
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return test_and_change_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
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}
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#ifdef CONFIG_PPC64
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static __inline__ unsigned long clear_bit_unlock_return_word(int nr,
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volatile unsigned long *addr)
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{
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unsigned long old, t;
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unsigned long *p = (unsigned long *)addr + BIT_WORD(nr);
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unsigned long mask = BIT_MASK(nr);
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__asm__ __volatile__ (
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PPC_RELEASE_BARRIER
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"1:" PPC_LLARX(%0,0,%3,0) "\n"
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"andc %1,%0,%2\n"
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PPC405_ERR77(0,%3)
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PPC_STLCX "%1,0,%3\n"
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"bne- 1b\n"
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: "=&r" (old), "=&r" (t)
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: "r" (mask), "r" (p)
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: "cc", "memory");
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return old;
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}
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/* This is a special function for mm/filemap.c */
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#define clear_bit_unlock_is_negative_byte(nr, addr) \
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(clear_bit_unlock_return_word(nr, addr) & BIT_MASK(PG_waiters))
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#endif /* CONFIG_PPC64 */
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#include <asm-generic/bitops/non-atomic.h>
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static __inline__ void __clear_bit_unlock(int nr, volatile unsigned long *addr)
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{
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__asm__ __volatile__(PPC_RELEASE_BARRIER "" ::: "memory");
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__clear_bit(nr, addr);
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}
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/*
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* Return the zero-based bit position (LE, not IBM bit numbering) of
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* the most significant 1-bit in a double word.
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*/
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#define __ilog2(x) ilog2(x)
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#include <asm-generic/bitops/ffz.h>
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#include <asm-generic/bitops/builtin-__ffs.h>
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#include <asm-generic/bitops/builtin-ffs.h>
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/*
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* fls: find last (most-significant) bit set.
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* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
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*/
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static __inline__ int fls(unsigned int x)
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{
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return 32 - __builtin_clz(x);
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}
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#include <asm-generic/bitops/builtin-__fls.h>
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static __inline__ int fls64(__u64 x)
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{
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return 64 - __builtin_clzll(x);
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}
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#ifdef CONFIG_PPC64
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unsigned int __arch_hweight8(unsigned int w);
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unsigned int __arch_hweight16(unsigned int w);
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unsigned int __arch_hweight32(unsigned int w);
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unsigned long __arch_hweight64(__u64 w);
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#include <asm-generic/bitops/const_hweight.h>
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#else
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#include <asm-generic/bitops/hweight.h>
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#endif
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#include <asm-generic/bitops/find.h>
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/* Little-endian versions */
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#include <asm-generic/bitops/le.h>
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/* Bitmap functions for the ext2 filesystem */
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#include <asm-generic/bitops/ext2-atomic-setbit.h>
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#include <asm-generic/bitops/sched.h>
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#endif /* __KERNEL__ */
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#endif /* _ASM_POWERPC_BITOPS_H */
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