Messages in this thread |  | | From | Nick Desaulniers <> | Date | Mon, 1 Jun 2020 13:18:50 -0700 | Subject | Re: [PATCH v2 04/10] x86/percpu: Clean up percpu_add_op() |
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On Sat, May 30, 2020 at 3:11 PM Brian Gerst <brgerst@gmail.com> wrote: > > The core percpu macros already have a switch on the data size, so the switch > in the x86 code is redundant and produces more dead code. > > Also use appropriate types for the width of the instructions. This avoids > errors when compiling with Clang. > > Signed-off-by: Brian Gerst <brgerst@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> --- > arch/x86/include/asm/percpu.h | 99 ++++++++--------------------------- > 1 file changed, 22 insertions(+), 77 deletions(-) > > diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h > index a40d2e055f58..2a24f3c795eb 100644 > --- a/arch/x86/include/asm/percpu.h > +++ b/arch/x86/include/asm/percpu.h > @@ -130,64 +130,32 @@ do { \ > : [val] __pcpu_reg_imm_##size(pto_val__)); \ > } while (0) > > +#define percpu_unary_op(size, qual, op, _var) \ > +({ \ > + asm qual (__pcpu_op1_##size(op, __percpu_arg([var])) \ > + : [var] "+m" (_var)); \ > +}) > + > /* > * Generate a percpu add to memory instruction and optimize code > * if one is added or subtracted. > */ > -#define percpu_add_op(qual, var, val) \ > +#define percpu_add_op(size, qual, var, val) \ > do { \ > - typedef typeof(var) pao_T__; \ > const int pao_ID__ = (__builtin_constant_p(val) && \ > ((val) == 1 || (val) == -1)) ? \ > (int)(val) : 0; \ > if (0) { \ > - pao_T__ pao_tmp__; \ > + typeof(var) pao_tmp__; \ > pao_tmp__ = (val); \ > (void)pao_tmp__; \ > } \ > - switch (sizeof(var)) { \ > - case 1: \ > - if (pao_ID__ == 1) \ > - asm qual ("incb "__percpu_arg(0) : "+m" (var)); \ > - else if (pao_ID__ == -1) \ > - asm qual ("decb "__percpu_arg(0) : "+m" (var)); \ > - else \ > - asm qual ("addb %1, "__percpu_arg(0) \ > - : "+m" (var) \ > - : "qi" ((pao_T__)(val))); \ > - break; \ > - case 2: \ > - if (pao_ID__ == 1) \ > - asm qual ("incw "__percpu_arg(0) : "+m" (var)); \ > - else if (pao_ID__ == -1) \ > - asm qual ("decw "__percpu_arg(0) : "+m" (var)); \ > - else \ > - asm qual ("addw %1, "__percpu_arg(0) \ > - : "+m" (var) \ > - : "ri" ((pao_T__)(val))); \ > - break; \ > - case 4: \ > - if (pao_ID__ == 1) \ > - asm qual ("incl "__percpu_arg(0) : "+m" (var)); \ > - else if (pao_ID__ == -1) \ > - asm qual ("decl "__percpu_arg(0) : "+m" (var)); \ > - else \ > - asm qual ("addl %1, "__percpu_arg(0) \ > - : "+m" (var) \ > - : "ri" ((pao_T__)(val))); \ > - break; \ > - case 8: \ > - if (pao_ID__ == 1) \ > - asm qual ("incq "__percpu_arg(0) : "+m" (var)); \ > - else if (pao_ID__ == -1) \ > - asm qual ("decq "__percpu_arg(0) : "+m" (var)); \ > - else \ > - asm qual ("addq %1, "__percpu_arg(0) \ > - : "+m" (var) \ > - : "re" ((pao_T__)(val))); \ > - break; \ > - default: __bad_percpu_size(); \ > - } \ > + if (pao_ID__ == 1) \ > + percpu_unary_op(size, qual, "inc", var); \ > + else if (pao_ID__ == -1) \ > + percpu_unary_op(size, qual, "dec", var); \ > + else \ > + percpu_to_op(size, qual, "add", var, val); \ > } while (0) > > #define percpu_from_op(size, qual, op, _var) \ > @@ -228,29 +196,6 @@ do { \ > pfo_ret__; \ > }) > > -#define percpu_unary_op(qual, op, var) \ > -({ \ > - switch (sizeof(var)) { \ > - case 1: \ > - asm qual (op "b "__percpu_arg(0) \ > - : "+m" (var)); \ > - break; \ > - case 2: \ > - asm qual (op "w "__percpu_arg(0) \ > - : "+m" (var)); \ > - break; \ > - case 4: \ > - asm qual (op "l "__percpu_arg(0) \ > - : "+m" (var)); \ > - break; \ > - case 8: \ > - asm qual (op "q "__percpu_arg(0) \ > - : "+m" (var)); \ > - break; \ > - default: __bad_percpu_size(); \ > - } \ > -}) > - > /* > * Add return operation > */ > @@ -388,9 +333,9 @@ do { \ > #define raw_cpu_write_1(pcp, val) percpu_to_op(1, , "mov", (pcp), val) > #define raw_cpu_write_2(pcp, val) percpu_to_op(2, , "mov", (pcp), val) > #define raw_cpu_write_4(pcp, val) percpu_to_op(4, , "mov", (pcp), val) > -#define raw_cpu_add_1(pcp, val) percpu_add_op(, (pcp), val) > -#define raw_cpu_add_2(pcp, val) percpu_add_op(, (pcp), val) > -#define raw_cpu_add_4(pcp, val) percpu_add_op(, (pcp), val) > +#define raw_cpu_add_1(pcp, val) percpu_add_op(1, , (pcp), val) > +#define raw_cpu_add_2(pcp, val) percpu_add_op(2, , (pcp), val) > +#define raw_cpu_add_4(pcp, val) percpu_add_op(4, , (pcp), val) > #define raw_cpu_and_1(pcp, val) percpu_to_op(1, , "and", (pcp), val) > #define raw_cpu_and_2(pcp, val) percpu_to_op(2, , "and", (pcp), val) > #define raw_cpu_and_4(pcp, val) percpu_to_op(4, , "and", (pcp), val) > @@ -419,9 +364,9 @@ do { \ > #define this_cpu_write_1(pcp, val) percpu_to_op(1, volatile, "mov", (pcp), val) > #define this_cpu_write_2(pcp, val) percpu_to_op(2, volatile, "mov", (pcp), val) > #define this_cpu_write_4(pcp, val) percpu_to_op(4, volatile, "mov", (pcp), val) > -#define this_cpu_add_1(pcp, val) percpu_add_op(volatile, (pcp), val) > -#define this_cpu_add_2(pcp, val) percpu_add_op(volatile, (pcp), val) > -#define this_cpu_add_4(pcp, val) percpu_add_op(volatile, (pcp), val) > +#define this_cpu_add_1(pcp, val) percpu_add_op(1, volatile, (pcp), val) > +#define this_cpu_add_2(pcp, val) percpu_add_op(2, volatile, (pcp), val) > +#define this_cpu_add_4(pcp, val) percpu_add_op(4, volatile, (pcp), val) > #define this_cpu_and_1(pcp, val) percpu_to_op(1, volatile, "and", (pcp), val) > #define this_cpu_and_2(pcp, val) percpu_to_op(2, volatile, "and", (pcp), val) > #define this_cpu_and_4(pcp, val) percpu_to_op(4, volatile, "and", (pcp), val) > @@ -470,7 +415,7 @@ do { \ > #ifdef CONFIG_X86_64 > #define raw_cpu_read_8(pcp) percpu_from_op(8, , "mov", pcp) > #define raw_cpu_write_8(pcp, val) percpu_to_op(8, , "mov", (pcp), val) > -#define raw_cpu_add_8(pcp, val) percpu_add_op(, (pcp), val) > +#define raw_cpu_add_8(pcp, val) percpu_add_op(8, , (pcp), val) > #define raw_cpu_and_8(pcp, val) percpu_to_op(8, , "and", (pcp), val) > #define raw_cpu_or_8(pcp, val) percpu_to_op(8, , "or", (pcp), val) > #define raw_cpu_add_return_8(pcp, val) percpu_add_return_op(, pcp, val) > @@ -479,7 +424,7 @@ do { \ > > #define this_cpu_read_8(pcp) percpu_from_op(8, volatile, "mov", pcp) > #define this_cpu_write_8(pcp, val) percpu_to_op(8, volatile, "mov", (pcp), val) > -#define this_cpu_add_8(pcp, val) percpu_add_op(volatile, (pcp), val) > +#define this_cpu_add_8(pcp, val) percpu_add_op(8, volatile, (pcp), val) > #define this_cpu_and_8(pcp, val) percpu_to_op(8, volatile, "and", (pcp), val) > #define this_cpu_or_8(pcp, val) percpu_to_op(8, volatile, "or", (pcp), val) > #define this_cpu_add_return_8(pcp, val) percpu_add_return_op(volatile, pcp, val) > -- > 2.25.4 >
-- Thanks, ~Nick Desaulniers
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