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authorPeter Zijlstra <peterz@infradead.org>2018-10-03 12:34:10 +0200
committerIngo Molnar <mingo@kernel.org>2018-10-16 17:33:54 +0200
commit288e4521f0f6717909933116563e66bb894ae2af (patch)
tree94fc1d93dd5bc2b09a39dd342545b2c564b850e3 /arch/x86/include/asm/rmwcc.h
parent756b1df4c2c82a1cdffeafa9d2aa76c92e7fb405 (diff)
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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>
Diffstat (limited to 'arch/x86/include/asm/rmwcc.h')
-rw-r--r--arch/x86/include/asm/rmwcc.h69
1 files changed, 41 insertions, 28 deletions
diff --git a/arch/x86/include/asm/rmwcc.h b/arch/x86/include/asm/rmwcc.h
index 4914a3e7c803..46ac84b506f5 100644
--- a/arch/x86/include/asm/rmwcc.h
+++ b/arch/x86/include/asm/rmwcc.h
@@ -2,56 +2,69 @@
#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, ...) \
-do { \
+#define __GEN_RMWcc(fullop, _var, cc, clobbers, ...) \
+({ \
+ bool c = false; \
asm_volatile_goto (fullop "; j" #cc " %l[cc_label]" \
- : : [counter] "m" (var), ## __VA_ARGS__ \
+ : : [var] "m" (_var), ## __VA_ARGS__ \
: clobbers : cc_label); \
- return 0; \
-cc_label: \
- return 1; \
-} while (0)
-
-#define __BINARY_RMWcc_ARG " %1, "
-
+ 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, ...) \
-do { \
+#define __GEN_RMWcc(fullop, _var, cc, clobbers, ...) \
+({ \
bool c; \
asm volatile (fullop CC_SET(cc) \
- : [counter] "+m" (var), CC_OUT(cc) (c) \
+ : [var] "+m" (_var), CC_OUT(cc) (c) \
: __VA_ARGS__ : clobbers); \
- return c; \
-} while (0)
-
-#define __BINARY_RMWcc_ARG " %2, "
+ c; \
+})
#endif /* defined(__GCC_ASM_FLAG_OUTPUTS__) || !defined(CC_HAVE_ASM_GOTO) */
-#define GEN_UNARY_RMWcc(op, var, arg0, cc) \
+#define GEN_UNARY_RMWcc_4(op, var, cc, arg0) \
__GEN_RMWcc(op " " arg0, var, cc, __CLOBBERS_MEM())
-#define GEN_UNARY_SUFFIXED_RMWcc(op, suffix, var, arg0, cc, clobbers...)\
- __GEN_RMWcc(op " " arg0 "\n\t" suffix, var, cc, \
- __CLOBBERS_MEM(clobbers))
+#define GEN_UNARY_RMWcc_3(op, var, cc) \
+ GEN_UNARY_RMWcc_4(op, var, cc, "%[var]")
-#define GEN_BINARY_RMWcc(op, var, vcon, val, arg0, cc) \
- __GEN_RMWcc(op __BINARY_RMWcc_ARG arg0, var, cc, \
- __CLOBBERS_MEM(), vcon (val))
+#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, vcon, val, arg0, cc, \
- clobbers...) \
- __GEN_RMWcc(op __BINARY_RMWcc_ARG arg0 "\n\t" suffix, var, cc, \
- __CLOBBERS_MEM(clobbers), vcon (val))
+#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 */