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| author | Luis R. Rodriguez <mcgrof@kernel.org> | 2016-06-28 12:27:13 -0700 |
|---|---|---|
| committer | Luis R. Rodriguez <mcgrof@kernel.org> | 2016-06-29 17:29:05 -0700 |
| commit | 31e11e2a3a34222eb781ef791e7d0515707e35bc (patch) | |
| tree | c5aacc860b257ad658fb49e74a3f8cc5b4e73a57 | |
| parent | 56b6b43926232e258d63bf5a981cc64575d27f8b (diff) | |
| download | linker-tables-31e11e2a3a34222eb781ef791e7d0515707e35bc.tar.gz | |
x86: add architecture enabled ps_shr()
This shows how we can add an architecture enabled optimization for
ps_shr(). This is currently disabled though as I'm sure the asm is
not right yet. Once the x86 asm is fixed in the header file
arch/x86/include/asm/ps_const.h just edit the top level Makefile and
uncomment:
#CFLAGS += -DCONFIG_HAVE_ARCH_PS_CONST
Expected synth driver output:
Synthetics: ps_shr(0xDEADBEEF, get_demo_shr) returns: 0x0000DEAD
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
| -rw-r--r-- | Makefile | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/asm.h | 17 | ||||
| -rw-r--r-- | arch/x86/include/asm/ps_const.h | 21 | ||||
| -rw-r--r-- | include/linux/ps_const.h | 4 |
4 files changed, 43 insertions, 0 deletions
@@ -2,6 +2,7 @@ CFLAGS += -O2 -g CFLAGS += -std=gnu99 -Wall -Werror CFLAGS += -pthread CFLAGS += -DCONFIG_KPROBES +#CFLAGS += -DCONFIG_HAVE_ARCH_PS_CONST INCLUDES = -I include/ -I arch/x86/include/ CFLAGS += $(INCLUDES) diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h new file mode 100644 index 0000000..155a529 --- /dev/null +++ b/arch/x86/include/asm/asm.h @@ -0,0 +1,17 @@ +#ifndef _ASM_X86_ASM_H + +#ifdef __ASSEMBLY__ +# define __ASM_FORM(x) x +# define __ASM_FORM_RAW(x) x +# define __ASM_FORM_COMMA(x) x, +#else +# define __ASM_FORM(x) " " #x " " +# define __ASM_FORM_RAW(x) #x +# define __ASM_FORM_COMMA(x) " " #x "," +#endif + +# define __ASM_SEL(a,b) __ASM_FORM(b) +# define __ASM_SEL_RAW(a,b) __ASM_FORM_RAW(b) +#define _ASM_PTR __ASM_SEL(.long, .quad) + +#endif /* _ASM_X86_ASM_H */ diff --git a/arch/x86/include/asm/ps_const.h b/arch/x86/include/asm/ps_const.h new file mode 100644 index 0000000..b9901f3 --- /dev/null +++ b/arch/x86/include/asm/ps_const.h @@ -0,0 +1,21 @@ +#ifndef __X86_PS_CONST +#define __X86_PS_CONST + +#include <linux/tables.h> +#include <asm/asm.h> + +#define ps_shr(_in, _func) \ +({ \ + __typeof__(_in) _out; \ + asm volatile( \ + "shr $0,%0\n" \ + "1:\n" \ + SECTION_TBL_STR(SECTION_INIT_DATA, ps_set_const_table, 01)\ + _ASM_PTR "1b-1, %P2, %P3\n" \ + ".popsection\n" \ + : "=rm" (_out) \ + : "0" (_in), "i" (SET_CONST_U8), "i" (_func)); \ + (_out); \ +}) + +#endif /* __X86_PS_CONST */ diff --git a/include/linux/ps_const.h b/include/linux/ps_const.h index 1747421..5eab3a1 100644 --- a/include/linux/ps_const.h +++ b/include/linux/ps_const.h @@ -21,6 +21,10 @@ struct ps_set_const { DECLARE_LINKTABLE(struct ps_set_const, ps_set_const_table); +#ifdef CONFIG_HAVE_ARCH_PS_CONST +#include <asm/ps_const.h> +#endif + /* * ps_ stands for "partially static", so we "partialloy static shift right" * You can optimize this for your architecture. |