| Message ID | 20221110164924.529386-7-heiko@sntech.de (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Zbb string optimizations and call support in alternatives | expand |
| Context | Check | Description |
|---|---|---|
| conchuod/tree_selection | fail | Guessing tree name failed |
On Thu, Nov 10, 2022 at 05:49:23PM +0100, Heiko Stuebner wrote: > From: Heiko Stuebner <heiko.stuebner@vrull.eu> > > Depending on supported extensions on specific RISC-V cores, > optimized str* functions might make sense. > > This adds basic infrastructure to allow patching the function calls > via alternatives later on. > > The main idea is to have the core str* functions be inline functions > which then call the most optimized variant and this call then be > replaced via alternatives. > > The big advantage is that we don't need additional calls. > Though we need to duplicate the generic functions as the main code > expects either itself or the architecture to provide the str* functions. > > The added *_generic functions are done in assembler (taken from > disassembling the main-kernel functions for now) to allow us to control > the used registers. > > Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu> > --- > arch/riscv/include/asm/string.h | 66 +++++++++++++++++++++++++++++++++ > arch/riscv/kernel/image-vars.h | 6 +-- > arch/riscv/lib/Makefile | 3 ++ > arch/riscv/lib/strcmp.S | 39 +++++++++++++++++++ > arch/riscv/lib/strlen.S | 29 +++++++++++++++ > arch/riscv/lib/strncmp.S | 41 ++++++++++++++++++++ > 6 files changed, 181 insertions(+), 3 deletions(-) > create mode 100644 arch/riscv/lib/strcmp.S > create mode 100644 arch/riscv/lib/strlen.S > create mode 100644 arch/riscv/lib/strncmp.S > > diff --git a/arch/riscv/include/asm/string.h b/arch/riscv/include/asm/string.h > index 909049366555..b98481d2d154 100644 > --- a/arch/riscv/include/asm/string.h > +++ b/arch/riscv/include/asm/string.h > @@ -18,6 +18,72 @@ extern asmlinkage void *__memcpy(void *, const void *, size_t); > #define __HAVE_ARCH_MEMMOVE > extern asmlinkage void *memmove(void *, const void *, size_t); > extern asmlinkage void *__memmove(void *, const void *, size_t); > + > +#define __HAVE_ARCH_STRCMP > +extern asmlinkage int __strcmp_generic(const char *cs, const char *ct); > + > +static inline int strcmp(const char *cs, const char *ct) > +{ > +#ifdef RISCV_EFISTUB > + return __strcmp_generic(cs, ct); > +#else > + register const char *a0 asm("a0") = cs; > + register const char *a1 asm("a1") = ct; > + register int a0_out asm("a0"); > + > + asm volatile("call __strcmp_generic\n\t" > + : "=r"(a0_out) > + : "r"(a0), "r"(a1) > + : "ra", "t0", "t1", "t2"); > + > + return a0_out; > +#endif > +} > + > +#define __HAVE_ARCH_STRNCMP > +extern asmlinkage int __strncmp_generic(const char *cs, > + const char *ct, size_t count); > + > +static inline int strncmp(const char *cs, const char *ct, size_t count) > +{ > +#ifdef RISCV_EFISTUB > + return __strncmp_generic(cs, ct, count); > +#else > + register const char *a0 asm("a0") = cs; > + register const char *a1 asm("a1") = ct; > + register size_t a2 asm("a2") = count; > + register int a0_out asm("a0"); > + > + asm volatile("call __strncmp_generic\n\t" > + : "=r"(a0_out) > + : "r"(a0), "r"(a1), "r"(a2) > + : "ra", "t0", "t1", "t2"); > + > + return a0_out; > +#endif > +} > + > +#define __HAVE_ARCH_STRLEN > +extern asmlinkage __kernel_size_t __strlen_generic(const char *); > + > +static inline __kernel_size_t strlen(const char *s) > +{ > +#ifdef RISCV_EFISTUB > + return __strlen_generic(s); > +#else > + register const char *a0 asm("a0") = s; > + register int a0_out asm("a0"); > + > + asm volatile( > + "call __strlen_generic\n\t" > + : "=r"(a0_out) > + : "r"(a0) > + : "ra", "t0", "t1"); > + > + return a0_out; > +#endif > +} > + > /* For those files which don't want to check by kasan. */ > #if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__) > #define memcpy(dst, src, len) __memcpy(dst, src, len) > diff --git a/arch/riscv/kernel/image-vars.h b/arch/riscv/kernel/image-vars.h > index d6e5f739905e..2f270b9fde63 100644 > --- a/arch/riscv/kernel/image-vars.h > +++ b/arch/riscv/kernel/image-vars.h > @@ -25,10 +25,10 @@ > */ > __efistub_memcmp = memcmp; > __efistub_memchr = memchr; > -__efistub_strlen = strlen; > +__efistub___strlen_generic = __strlen_generic; > __efistub_strnlen = strnlen; > -__efistub_strcmp = strcmp; > -__efistub_strncmp = strncmp; > +__efistub___strcmp_generic = __strcmp_generic; > +__efistub___strncmp_generic = __strncmp_generic; > __efistub_strrchr = strrchr; > > __efistub__start = _start; > diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile > index 25d5c9664e57..6c74b0bedd60 100644 > --- a/arch/riscv/lib/Makefile > +++ b/arch/riscv/lib/Makefile > @@ -3,6 +3,9 @@ lib-y += delay.o > lib-y += memcpy.o > lib-y += memset.o > lib-y += memmove.o > +lib-y += strcmp.o > +lib-y += strlen.o > +lib-y += strncmp.o > lib-$(CONFIG_MMU) += uaccess.o > lib-$(CONFIG_64BIT) += tishift.o > > diff --git a/arch/riscv/lib/strcmp.S b/arch/riscv/lib/strcmp.S > new file mode 100644 > index 000000000000..f23a5c5e39d8 > --- /dev/null > +++ b/arch/riscv/lib/strcmp.S > @@ -0,0 +1,39 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > + > +#include <linux/linkage.h> > +#include <asm/asm.h> > +#include <asm-generic/export.h> > + > +/* int __strcmp_generic(const char *cs, const char *ct) */ > +ENTRY(__strcmp_generic) > + /* > + * Returns > + * a0 - comparison result, like strncmp The strncmp_generic one below says "like strncmp" too. Given the below copy paste stuff, is this one copy paste or intentional? > + * > + * Parameters > + * a0 - string1 > + * a1 - string2 > + * a2 - number of characters to compare Above line is a copy paste error? > + * > + * Clobbers > + * t0, t1, t2, t3, t4, t5 As is this one? Other than those, seems to make sense? Reviewed-by: Conor Dooley <conor.dooley@microchip.com> > + */ > + mv t2, a1 > +1: > + lbu t1, 0(a0) > + lbu t0, 0(a1) > + addi a0, a0, 1 > + addi a1, a1, 1 > + beq t1, t0, 3f > + li a0, 1 > + bgeu t1, t0, 2f > + li a0, -1 > +2: > + mv a1, t2 > + ret > +3: > + bnez t1, 1b > + li a0, 0 > + j 2b > +END(__strcmp_generic) > +EXPORT_SYMBOL(__strcmp_generic) > diff --git a/arch/riscv/lib/strlen.S b/arch/riscv/lib/strlen.S > new file mode 100644 > index 000000000000..e0e7440ac724 > --- /dev/null > +++ b/arch/riscv/lib/strlen.S > @@ -0,0 +1,29 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > + > +#include <linux/linkage.h> > +#include <asm/asm.h> > +#include <asm-generic/export.h> > + > +/* int __strlen_generic(const char *s) */ > +ENTRY(__strlen_generic) > + /* > + * Returns > + * a0 - string length > + * > + * Parameters > + * a0 - String to measure > + * > + * Clobbers: > + * t0, t1 > + */ > + mv t1, a0 > +1: > + lbu t0, 0(t1) > + bnez t0, 2f > + sub a0, t1, a0 > + ret > +2: > + addi t1, t1, 1 > + j 1b > +END(__strlen_generic) > +EXPORT_SYMBOL(__strlen_generic) > diff --git a/arch/riscv/lib/strncmp.S b/arch/riscv/lib/strncmp.S > new file mode 100644 > index 000000000000..8d271cd0df72 > --- /dev/null > +++ b/arch/riscv/lib/strncmp.S > @@ -0,0 +1,41 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > + > +#include <linux/linkage.h> > +#include <asm/asm.h> > +#include <asm-generic/export.h> > + > +/* int __strncmp_generic(const char *cs, const char *ct, size_t count) */ > +ENTRY(__strncmp_generic) > + /* > + * Returns > + * a0 - comparison result, like strncmp > + * > + * Parameters > + * a0 - string1 > + * a1 - string2 > + * a2 - number of characters to compare > + * > + * Clobbers > + * t0, t1, t2 > + */ > + li t0, 0 > +1: > + beq a2, t0, 4f > + add t1, a0, t0 > + add t2, a1, t0 > + lbu t1, 0(t1) > + lbu t2, 0(t2) > + beq t1, t2, 3f > + li a0, 1 > + bgeu t1, t2, 2f > + li a0, -1 > +2: > + ret > +3: > + addi t0, t0, 1 > + bnez t1, 1b > +4: > + li a0, 0 > + j 2b > +END(__strncmp_generic) > +EXPORT_SYMBOL(__strncmp_generic) > -- > 2.35.1 > > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv
diff --git a/arch/riscv/include/asm/string.h b/arch/riscv/include/asm/string.h index 909049366555..b98481d2d154 100644 --- a/arch/riscv/include/asm/string.h +++ b/arch/riscv/include/asm/string.h @@ -18,6 +18,72 @@ extern asmlinkage void *__memcpy(void *, const void *, size_t); #define __HAVE_ARCH_MEMMOVE extern asmlinkage void *memmove(void *, const void *, size_t); extern asmlinkage void *__memmove(void *, const void *, size_t); + +#define __HAVE_ARCH_STRCMP +extern asmlinkage int __strcmp_generic(const char *cs, const char *ct); + +static inline int strcmp(const char *cs, const char *ct) +{ +#ifdef RISCV_EFISTUB + return __strcmp_generic(cs, ct); +#else + register const char *a0 asm("a0") = cs; + register const char *a1 asm("a1") = ct; + register int a0_out asm("a0"); + + asm volatile("call __strcmp_generic\n\t" + : "=r"(a0_out) + : "r"(a0), "r"(a1) + : "ra", "t0", "t1", "t2"); + + return a0_out; +#endif +} + +#define __HAVE_ARCH_STRNCMP +extern asmlinkage int __strncmp_generic(const char *cs, + const char *ct, size_t count); + +static inline int strncmp(const char *cs, const char *ct, size_t count) +{ +#ifdef RISCV_EFISTUB + return __strncmp_generic(cs, ct, count); +#else + register const char *a0 asm("a0") = cs; + register const char *a1 asm("a1") = ct; + register size_t a2 asm("a2") = count; + register int a0_out asm("a0"); + + asm volatile("call __strncmp_generic\n\t" + : "=r"(a0_out) + : "r"(a0), "r"(a1), "r"(a2) + : "ra", "t0", "t1", "t2"); + + return a0_out; +#endif +} + +#define __HAVE_ARCH_STRLEN +extern asmlinkage __kernel_size_t __strlen_generic(const char *); + +static inline __kernel_size_t strlen(const char *s) +{ +#ifdef RISCV_EFISTUB + return __strlen_generic(s); +#else + register const char *a0 asm("a0") = s; + register int a0_out asm("a0"); + + asm volatile( + "call __strlen_generic\n\t" + : "=r"(a0_out) + : "r"(a0) + : "ra", "t0", "t1"); + + return a0_out; +#endif +} + /* For those files which don't want to check by kasan. */ #if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__) #define memcpy(dst, src, len) __memcpy(dst, src, len) diff --git a/arch/riscv/kernel/image-vars.h b/arch/riscv/kernel/image-vars.h index d6e5f739905e..2f270b9fde63 100644 --- a/arch/riscv/kernel/image-vars.h +++ b/arch/riscv/kernel/image-vars.h @@ -25,10 +25,10 @@ */ __efistub_memcmp = memcmp; __efistub_memchr = memchr; -__efistub_strlen = strlen; +__efistub___strlen_generic = __strlen_generic; __efistub_strnlen = strnlen; -__efistub_strcmp = strcmp; -__efistub_strncmp = strncmp; +__efistub___strcmp_generic = __strcmp_generic; +__efistub___strncmp_generic = __strncmp_generic; __efistub_strrchr = strrchr; __efistub__start = _start; diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile index 25d5c9664e57..6c74b0bedd60 100644 --- a/arch/riscv/lib/Makefile +++ b/arch/riscv/lib/Makefile @@ -3,6 +3,9 @@ lib-y += delay.o lib-y += memcpy.o lib-y += memset.o lib-y += memmove.o +lib-y += strcmp.o +lib-y += strlen.o +lib-y += strncmp.o lib-$(CONFIG_MMU) += uaccess.o lib-$(CONFIG_64BIT) += tishift.o diff --git a/arch/riscv/lib/strcmp.S b/arch/riscv/lib/strcmp.S new file mode 100644 index 000000000000..f23a5c5e39d8 --- /dev/null +++ b/arch/riscv/lib/strcmp.S @@ -0,0 +1,39 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include <linux/linkage.h> +#include <asm/asm.h> +#include <asm-generic/export.h> + +/* int __strcmp_generic(const char *cs, const char *ct) */ +ENTRY(__strcmp_generic) + /* + * Returns + * a0 - comparison result, like strncmp + * + * Parameters + * a0 - string1 + * a1 - string2 + * a2 - number of characters to compare + * + * Clobbers + * t0, t1, t2, t3, t4, t5 + */ + mv t2, a1 +1: + lbu t1, 0(a0) + lbu t0, 0(a1) + addi a0, a0, 1 + addi a1, a1, 1 + beq t1, t0, 3f + li a0, 1 + bgeu t1, t0, 2f + li a0, -1 +2: + mv a1, t2 + ret +3: + bnez t1, 1b + li a0, 0 + j 2b +END(__strcmp_generic) +EXPORT_SYMBOL(__strcmp_generic) diff --git a/arch/riscv/lib/strlen.S b/arch/riscv/lib/strlen.S new file mode 100644 index 000000000000..e0e7440ac724 --- /dev/null +++ b/arch/riscv/lib/strlen.S @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include <linux/linkage.h> +#include <asm/asm.h> +#include <asm-generic/export.h> + +/* int __strlen_generic(const char *s) */ +ENTRY(__strlen_generic) + /* + * Returns + * a0 - string length + * + * Parameters + * a0 - String to measure + * + * Clobbers: + * t0, t1 + */ + mv t1, a0 +1: + lbu t0, 0(t1) + bnez t0, 2f + sub a0, t1, a0 + ret +2: + addi t1, t1, 1 + j 1b +END(__strlen_generic) +EXPORT_SYMBOL(__strlen_generic) diff --git a/arch/riscv/lib/strncmp.S b/arch/riscv/lib/strncmp.S new file mode 100644 index 000000000000..8d271cd0df72 --- /dev/null +++ b/arch/riscv/lib/strncmp.S @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include <linux/linkage.h> +#include <asm/asm.h> +#include <asm-generic/export.h> + +/* int __strncmp_generic(const char *cs, const char *ct, size_t count) */ +ENTRY(__strncmp_generic) + /* + * Returns + * a0 - comparison result, like strncmp + * + * Parameters + * a0 - string1 + * a1 - string2 + * a2 - number of characters to compare + * + * Clobbers + * t0, t1, t2 + */ + li t0, 0 +1: + beq a2, t0, 4f + add t1, a0, t0 + add t2, a1, t0 + lbu t1, 0(t1) + lbu t2, 0(t2) + beq t1, t2, 3f + li a0, 1 + bgeu t1, t2, 2f + li a0, -1 +2: + ret +3: + addi t0, t0, 1 + bnez t1, 1b +4: + li a0, 0 + j 2b +END(__strncmp_generic) +EXPORT_SYMBOL(__strncmp_generic)