linux_dsm_epyc7002/arch/x86/include/asm/rmwcc.h
Peter Zijlstra 288e4521f0 x86/asm: 'Simplify' GEN_*_RMWcc() macros
Currently the GEN_*_RMWcc() macros include a return statement, which
pretty much mandates we directly wrap them in a (inline) function.

Macros with return statements are tricky and, as per the above, limit
use, so remove the return statement and make them
statement-expressions. This allows them to be used more widely.

Also, shuffle the arguments a bit. Place the @cc argument as 3rd, this
makes it consistent between UNARY and BINARY, but more importantly, it
makes the @arg0 argument last.

Since the @arg0 argument is now last, we can do CPP trickery and make
it an optional argument, simplifying the users; 17 out of 18
occurences do not need this argument.

Finally, change to asm symbolic names, instead of the numeric ordering
of operands, which allows us to get rid of __BINARY_RMWcc_ARG and get
cleaner code overall.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: JBeulich@suse.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bp@alien8.de
Cc: hpa@linux.intel.com
Link: https://lkml.kernel.org/r/20181003130957.108960094@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-16 17:33:54 +02:00

71 lines
2.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_RMWcc
#define _ASM_X86_RMWcc
/* This counts to 12. Any more, it will return 13th argument. */
#define __RMWcc_ARGS(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _n, X...) _n
#define RMWcc_ARGS(X...) __RMWcc_ARGS(, ##X, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
#define __RMWcc_CONCAT(a, b) a ## b
#define RMWcc_CONCAT(a, b) __RMWcc_CONCAT(a, b)
#define __CLOBBERS_MEM(clb...) "memory", ## clb
#if !defined(__GCC_ASM_FLAG_OUTPUTS__) && defined(CC_HAVE_ASM_GOTO)
/* Use asm goto */
#define __GEN_RMWcc(fullop, _var, cc, clobbers, ...) \
({ \
bool c = false; \
asm_volatile_goto (fullop "; j" #cc " %l[cc_label]" \
: : [var] "m" (_var), ## __VA_ARGS__ \
: clobbers : cc_label); \
if (0) { \
cc_label: c = true; \
} \
c; \
})
#else /* defined(__GCC_ASM_FLAG_OUTPUTS__) || !defined(CC_HAVE_ASM_GOTO) */
/* Use flags output or a set instruction */
#define __GEN_RMWcc(fullop, _var, cc, clobbers, ...) \
({ \
bool c; \
asm volatile (fullop CC_SET(cc) \
: [var] "+m" (_var), CC_OUT(cc) (c) \
: __VA_ARGS__ : clobbers); \
c; \
})
#endif /* defined(__GCC_ASM_FLAG_OUTPUTS__) || !defined(CC_HAVE_ASM_GOTO) */
#define GEN_UNARY_RMWcc_4(op, var, cc, arg0) \
__GEN_RMWcc(op " " arg0, var, cc, __CLOBBERS_MEM())
#define GEN_UNARY_RMWcc_3(op, var, cc) \
GEN_UNARY_RMWcc_4(op, var, cc, "%[var]")
#define GEN_UNARY_RMWcc(X...) RMWcc_CONCAT(GEN_UNARY_RMWcc_, RMWcc_ARGS(X))(X)
#define GEN_BINARY_RMWcc_6(op, var, cc, vcon, _val, arg0) \
__GEN_RMWcc(op " %[val], " arg0, var, cc, \
__CLOBBERS_MEM(), [val] vcon (_val))
#define GEN_BINARY_RMWcc_5(op, var, cc, vcon, val) \
GEN_BINARY_RMWcc_6(op, var, cc, vcon, val, "%[var]")
#define GEN_BINARY_RMWcc(X...) RMWcc_CONCAT(GEN_BINARY_RMWcc_, RMWcc_ARGS(X))(X)
#define GEN_UNARY_SUFFIXED_RMWcc(op, suffix, var, cc, clobbers...) \
__GEN_RMWcc(op " %[var]\n\t" suffix, var, cc, \
__CLOBBERS_MEM(clobbers))
#define GEN_BINARY_SUFFIXED_RMWcc(op, suffix, var, cc, vcon, _val, clobbers...)\
__GEN_RMWcc(op " %[val], %[var]\n\t" suffix, var, cc, \
__CLOBBERS_MEM(clobbers), [val] vcon (_val))
#endif /* _ASM_X86_RMWcc */