[PATCH] riscv: assembler versions of memcpy, memmove, memset

Leo Liang ycliang at andestech.com
Fri Mar 26 09:24:34 CET 2021


On Sat, Mar 20, 2021 at 12:31:35PM +0000, Heinrich Schuchardt wrote:
> Provide optimized versions of memcpy(), memmove(), memset() copied from
> the Linux kernel.
> 
> Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
> ---
>  arch/riscv/Kconfig              |  78 ++++++++++++++++++++++
>  arch/riscv/include/asm/string.h |  36 +++++-----
>  arch/riscv/lib/Makefile         |   5 ++
>  arch/riscv/lib/memcpy.S         | 108 ++++++++++++++++++++++++++++++
>  arch/riscv/lib/memmove.S        |  64 ++++++++++++++++++
>  arch/riscv/lib/memset.S         | 113 ++++++++++++++++++++++++++++++++
>  6 files changed, 383 insertions(+), 21 deletions(-)
>  create mode 100644 arch/riscv/lib/memcpy.S
>  create mode 100644 arch/riscv/lib/memmove.S
>  create mode 100644 arch/riscv/lib/memset.S
> 
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 55eaee2da6..7d0bd73ce2 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -271,4 +271,82 @@ config STACK_SIZE_SHIFT
>  config OF_BOARD_FIXUP
>  	default y if OF_SEPARATE && RISCV_SMODE
> 
> +config USE_ARCH_MEMCPY
> +	bool "Use an assembly optimized implementation of memcpy"
> +	default y
> +	help
> +	  Enable the generation of an optimized version of memcpy.
> +	  Such an implementation may be faster under some conditions
> +	  but may increase the binary size.
> +
> +config SPL_USE_ARCH_MEMCPY
> +	bool "Use an assembly optimized implementation of memcpy for SPL"
> +	default y if USE_ARCH_MEMCPY
> +	depends on SPL
> +	help
> +	  Enable the generation of an optimized version of memcpy.
> +	  Such an implementation may be faster under some conditions
> +	  but may increase the binary size.
> +
> +config TPL_USE_ARCH_MEMCPY
> +	bool "Use an assembly optimized implementation of memcpy for TPL"
> +	default y if USE_ARCH_MEMCPY
> +	depends on TPL
> +	help
> +	  Enable the generation of an optimized version of memcpy.
> +	  Such an implementation may be faster under some conditions
> +	  but may increase the binary size.
> +
> +config USE_ARCH_MEMMOVE
> +	bool "Use an assembly optimized implementation of memmove"
> +	default y
> +	help
> +	  Enable the generation of an optimized version of memmove.
> +	  Such an implementation may be faster under some conditions
> +	  but may increase the binary size.
> +
> +config SPL_USE_ARCH_MEMMOVE
> +	bool "Use an assembly optimized implementation of memmove for SPL"
> +	default y if USE_ARCH_MEMCPY
> +	depends on SPL
> +	help
> +	  Enable the generation of an optimized version of memmove.
> +	  Such an implementation may be faster under some conditions
> +	  but may increase the binary size.
> +
> +config TPL_USE_ARCH_MEMMOVE
> +	bool "Use an assembly optimized implementation of memmove for TPL"
> +	default y if USE_ARCH_MEMCPY
> +	depends on TPL
> +	help
> +	  Enable the generation of an optimized version of memmove.
> +	  Such an implementation may be faster under some conditions
> +	  but may increase the binary size.
> +
> +config USE_ARCH_MEMSET
> +	bool "Use an assembly optimized implementation of memset"
> +	default y
> +	help
> +	  Enable the generation of an optimized version of memset.
> +	  Such an implementation may be faster under some conditions
> +	  but may increase the binary size.
> +
> +config SPL_USE_ARCH_MEMSET
> +	bool "Use an assembly optimized implementation of memset for SPL"
> +	default y if USE_ARCH_MEMSET
> +	depends on SPL
> +	help
> +	  Enable the generation of an optimized version of memset.
> +	  Such an implementation may be faster under some conditions
> +	  but may increase the binary size.
> +
> +config TPL_USE_ARCH_MEMSET
> +	bool "Use an assembly optimized implementation of memset for TPL"
> +	default y if USE_ARCH_MEMSET
> +	depends on TPL
> +	help
> +	  Enable the generation of an optimized version of memset.
> +	  Such an implementation may be faster under some conditions
> +	  but may increase the binary size.
> +
>  endmenu
> diff --git a/arch/riscv/include/asm/string.h b/arch/riscv/include/asm/string.h
> index 0fc3424a2f..7dee3e4c9f 100644
> --- a/arch/riscv/include/asm/string.h
> +++ b/arch/riscv/include/asm/string.h
> @@ -19,31 +19,25 @@
> 
>  #undef __HAVE_ARCH_STRRCHR
>  #undef __HAVE_ARCH_STRCHR
> -#undef __HAVE_ARCH_MEMCPY
> -#undef __HAVE_ARCH_MEMMOVE
>  #undef __HAVE_ARCH_MEMCHR
>  #undef __HAVE_ARCH_MEMZERO
> -#undef __HAVE_ARCH_MEMSET
> 
> -#ifdef CONFIG_MARCO_MEMSET
> -#define memset(_p, _v, _n)	\
> -	(typeof(_p) (p) = (_p); \
> -	 typeof(_v) (v) = (_v); \
> -	 typeof(_n) (n) = (_n); \
> -	 {								\
> -		if ((n) != 0) {						\
> -			if (__builtin_constant_p((v)) && (v) == 0)	\
> -				__memzero((p), (n));			\
> -			else						\
> -				memset((p), (v), (n));			\
> -		}							\
> -		(p);							\
> -	})
> +#undef __HAVE_ARCH_MEMCPY
> +#if CONFIG_IS_ENABLED(USE_ARCH_MEMCPY)
> +#define __HAVE_ARCH_MEMCPY
> +#endif
> +extern void *memcpy(void *, const void *, __kernel_size_t);
> +
> +#undef __HAVE_ARCH_MEMMOVE
> +#if CONFIG_IS_ENABLED(USE_ARCH_MEMMOVE)
> +#define __HAVE_ARCH_MEMMOVE
> +#endif
> +extern void *memmove(void *, const void *, __kernel_size_t);
> 
> -#define memzero(_p, _n) \
> -	(typeof(_p) (p) = (_p); \
> -	 typeof(_n) (n) = (_n); \
> -	 { if ((n) != 0) __memzero((p), (n)); (p); })
> +#undef __HAVE_ARCH_MEMZERO
> +#if CONFIG_IS_ENABLED(USE_ARCH_MEMSET)
> +#define __HAVE_ARCH_MEMSET
>  #endif
> +extern void *memset(void *, int, __kernel_size_t);
> 
>  #endif /* __ASM_RISCV_STRING_H */
> diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
> index 12c14f2019..1c1500f5b3 100644
> --- a/arch/riscv/lib/Makefile
> +++ b/arch/riscv/lib/Makefile
> @@ -36,3 +36,8 @@ CFLAGS_REMOVE_$(EFI_RELOC) := $(CFLAGS_NON_EFI)
>  extra-$(CONFIG_CMD_BOOTEFI_HELLO_COMPILE) += $(EFI_CRT0) $(EFI_RELOC)
>  extra-$(CONFIG_CMD_BOOTEFI_SELFTEST) += $(EFI_CRT0) $(EFI_RELOC)
>  extra-$(CONFIG_EFI) += $(EFI_CRT0) $(EFI_RELOC)
> +
> +obj-$(CONFIG_$(SPL_TPL_)USE_ARCH_MEMSET) += memset.o
> +obj-$(CONFIG_$(SPL_TPL_)USE_ARCH_MEMMOVE) += memmove.o
> +obj-$(CONFIG_$(SPL_TPL_)USE_ARCH_MEMCPY) += memcpy.o
> +obj-$(CONFIG_$(SPL_TPL_)USE_ARCH_MEMCPY) += memcpy.o

The above line is duplicated.

> diff --git a/arch/riscv/lib/memcpy.S b/arch/riscv/lib/memcpy.S
> new file mode 100644
> index 0000000000..51ab716253
> --- /dev/null
> +++ b/arch/riscv/lib/memcpy.S
> @@ -0,0 +1,108 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2013 Regents of the University of California
> + */
> +
> +#include <linux/linkage.h>
> +#include <asm/asm.h>
> +
> +/* void *memcpy(void *, const void *, size_t) */
> +ENTRY(__memcpy)
> +WEAK(memcpy)
> +	move t6, a0  /* Preserve return value */
> +
> +	/* Defer to byte-oriented copy for small sizes */
> +	sltiu a3, a2, 128
> +	bnez a3, 4f
> +	/* Use word-oriented copy only if low-order bits match */
> +	andi a3, t6, SZREG-1
> +	andi a4, a1, SZREG-1
> +	bne a3, a4, 4f
> +
> +	beqz a3, 2f  /* Skip if already aligned */
> +	/*
> +	 * Round to nearest double word-aligned address
> +	 * greater than or equal to start address
> +	 */
> +	andi a3, a1, ~(SZREG-1)
> +	addi a3, a3, SZREG
> +	/* Handle initial misalignment */
> +	sub a4, a3, a1
> +1:
> +	lb a5, 0(a1)
> +	addi a1, a1, 1
> +	sb a5, 0(t6)
> +	addi t6, t6, 1
> +	bltu a1, a3, 1b
> +	sub a2, a2, a4  /* Update count */
> +
> +2:
> +	andi a4, a2, ~((16*SZREG)-1)
> +	beqz a4, 4f
> +	add a3, a1, a4
> +3:
> +	REG_L a4,       0(a1)
> +	REG_L a5,   SZREG(a1)
> +	REG_L a6, 2*SZREG(a1)
> +	REG_L a7, 3*SZREG(a1)
> +	REG_L t0, 4*SZREG(a1)
> +	REG_L t1, 5*SZREG(a1)
> +	REG_L t2, 6*SZREG(a1)
> +	REG_L t3, 7*SZREG(a1)
> +	REG_L t4, 8*SZREG(a1)
> +	REG_L t5, 9*SZREG(a1)
> +	REG_S a4,       0(t6)
> +	REG_S a5,   SZREG(t6)
> +	REG_S a6, 2*SZREG(t6)
> +	REG_S a7, 3*SZREG(t6)
> +	REG_S t0, 4*SZREG(t6)
> +	REG_S t1, 5*SZREG(t6)
> +	REG_S t2, 6*SZREG(t6)
> +	REG_S t3, 7*SZREG(t6)
> +	REG_S t4, 8*SZREG(t6)
> +	REG_S t5, 9*SZREG(t6)
> +	REG_L a4, 10*SZREG(a1)
> +	REG_L a5, 11*SZREG(a1)
> +	REG_L a6, 12*SZREG(a1)
> +	REG_L a7, 13*SZREG(a1)
> +	REG_L t0, 14*SZREG(a1)
> +	REG_L t1, 15*SZREG(a1)
> +	addi a1, a1, 16*SZREG
> +	REG_S a4, 10*SZREG(t6)
> +	REG_S a5, 11*SZREG(t6)
> +	REG_S a6, 12*SZREG(t6)
> +	REG_S a7, 13*SZREG(t6)
> +	REG_S t0, 14*SZREG(t6)
> +	REG_S t1, 15*SZREG(t6)
> +	addi t6, t6, 16*SZREG
> +	bltu a1, a3, 3b
> +	andi a2, a2, (16*SZREG)-1  /* Update count */
> +
> +4:
> +	/* Handle trailing misalignment */
> +	beqz a2, 6f
> +	add a3, a1, a2
> +
> +	/* Use word-oriented copy if co-aligned to word boundary */
> +	or a5, a1, t6
> +	or a5, a5, a3
> +	andi a5, a5, 3
> +	bnez a5, 5f
> +7:
> +	lw a4, 0(a1)
> +	addi a1, a1, 4
> +	sw a4, 0(t6)
> +	addi t6, t6, 4
> +	bltu a1, a3, 7b
> +
> +	ret
> +
> +5:
> +	lb a4, 0(a1)
> +	addi a1, a1, 1
> +	sb a4, 0(t6)
> +	addi t6, t6, 1
> +	bltu a1, a3, 5b
> +6:
> +	ret
> +END(__memcpy)
> diff --git a/arch/riscv/lib/memmove.S b/arch/riscv/lib/memmove.S
> new file mode 100644
> index 0000000000..07d1d2152b
> --- /dev/null
> +++ b/arch/riscv/lib/memmove.S
> @@ -0,0 +1,64 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +#include <linux/linkage.h>
> +#include <asm/asm.h>
> +
> +ENTRY(__memmove)
> +WEAK(memmove)
> +        move    t0, a0
> +        move    t1, a1
> +
> +        beq     a0, a1, exit_memcpy
> +        beqz    a2, exit_memcpy
> +        srli    t2, a2, 0x2
> +
> +        slt     t3, a0, a1
> +        beqz    t3, do_reverse
> +
> +        andi    a2, a2, 0x3
> +        li      t4, 1
> +        beqz    t2, byte_copy
> +
> +word_copy:
> +        lw      t3, 0(a1)
> +        addi    t2, t2, -1
> +        addi    a1, a1, 4
> +        sw      t3, 0(a0)
> +        addi    a0, a0, 4
> +        bnez    t2, word_copy
> +        beqz    a2, exit_memcpy
> +        j       byte_copy
> +
> +do_reverse:
> +        add     a0, a0, a2
> +        add     a1, a1, a2
> +        andi    a2, a2, 0x3
> +        li      t4, -1
> +        beqz    t2, reverse_byte_copy
> +
> +reverse_word_copy:
> +        addi    a1, a1, -4
> +        addi    t2, t2, -1
> +        lw      t3, 0(a1)
> +        addi    a0, a0, -4
> +        sw      t3, 0(a0)
> +        bnez    t2, reverse_word_copy
> +        beqz    a2, exit_memcpy
> +
> +reverse_byte_copy:
> +        addi    a0, a0, -1
> +        addi    a1, a1, -1
> +
> +byte_copy:
> +        lb      t3, 0(a1)
> +        addi    a2, a2, -1
> +        sb      t3, 0(a0)
> +        add     a1, a1, t4
> +        add     a0, a0, t4
> +        bnez    a2, byte_copy
> +
> +exit_memcpy:
> +        move a0, t0
> +        move a1, t1
> +        ret
> +END(__memmove)
> diff --git a/arch/riscv/lib/memset.S b/arch/riscv/lib/memset.S
> new file mode 100644
> index 0000000000..34c5360c67
> --- /dev/null
> +++ b/arch/riscv/lib/memset.S
> @@ -0,0 +1,113 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2013 Regents of the University of California
> + */
> +
> +
> +#include <linux/linkage.h>
> +#include <asm/asm.h>
> +
> +/* void *memset(void *, int, size_t) */
> +ENTRY(__memset)
> +WEAK(memset)
> +	move t0, a0  /* Preserve return value */
> +
> +	/* Defer to byte-oriented fill for small sizes */
> +	sltiu a3, a2, 16
> +	bnez a3, 4f
> +
> +	/*
> +	 * Round to nearest XLEN-aligned address
> +	 * greater than or equal to start address
> +	 */
> +	addi a3, t0, SZREG-1
> +	andi a3, a3, ~(SZREG-1)
> +	beq a3, t0, 2f  /* Skip if already aligned */
> +	/* Handle initial misalignment */
> +	sub a4, a3, t0
> +1:
> +	sb a1, 0(t0)
> +	addi t0, t0, 1
> +	bltu t0, a3, 1b
> +	sub a2, a2, a4  /* Update count */
> +
> +2: /* Duff's device with 32 XLEN stores per iteration */
> +	/* Broadcast value into all bytes */
> +	andi a1, a1, 0xff
> +	slli a3, a1, 8
> +	or a1, a3, a1
> +	slli a3, a1, 16
> +	or a1, a3, a1
> +#ifdef CONFIG_64BIT
> +	slli a3, a1, 32
> +	or a1, a3, a1
> +#endif
> +
> +	/* Calculate end address */
> +	andi a4, a2, ~(SZREG-1)
> +	add a3, t0, a4
> +
> +	andi a4, a4, 31*SZREG  /* Calculate remainder */
> +	beqz a4, 3f            /* Shortcut if no remainder */
> +	neg a4, a4
> +	addi a4, a4, 32*SZREG  /* Calculate initial offset */
> +
> +	/* Adjust start address with offset */
> +	sub t0, t0, a4
> +
> +	/* Jump into loop body */
> +	/* Assumes 32-bit instruction lengths */
> +	la a5, 3f
> +#ifdef CONFIG_64BIT
> +	srli a4, a4, 1
> +#endif
> +	add a5, a5, a4
> +	jr a5
> +3:
> +	REG_S a1,        0(t0)
> +	REG_S a1,    SZREG(t0)
> +	REG_S a1,  2*SZREG(t0)
> +	REG_S a1,  3*SZREG(t0)
> +	REG_S a1,  4*SZREG(t0)
> +	REG_S a1,  5*SZREG(t0)
> +	REG_S a1,  6*SZREG(t0)
> +	REG_S a1,  7*SZREG(t0)
> +	REG_S a1,  8*SZREG(t0)
> +	REG_S a1,  9*SZREG(t0)
> +	REG_S a1, 10*SZREG(t0)
> +	REG_S a1, 11*SZREG(t0)
> +	REG_S a1, 12*SZREG(t0)
> +	REG_S a1, 13*SZREG(t0)
> +	REG_S a1, 14*SZREG(t0)
> +	REG_S a1, 15*SZREG(t0)
> +	REG_S a1, 16*SZREG(t0)
> +	REG_S a1, 17*SZREG(t0)
> +	REG_S a1, 18*SZREG(t0)
> +	REG_S a1, 19*SZREG(t0)
> +	REG_S a1, 20*SZREG(t0)
> +	REG_S a1, 21*SZREG(t0)
> +	REG_S a1, 22*SZREG(t0)
> +	REG_S a1, 23*SZREG(t0)
> +	REG_S a1, 24*SZREG(t0)
> +	REG_S a1, 25*SZREG(t0)
> +	REG_S a1, 26*SZREG(t0)
> +	REG_S a1, 27*SZREG(t0)
> +	REG_S a1, 28*SZREG(t0)
> +	REG_S a1, 29*SZREG(t0)
> +	REG_S a1, 30*SZREG(t0)
> +	REG_S a1, 31*SZREG(t0)
> +	addi t0, t0, 32*SZREG
> +	bltu t0, a3, 3b
> +	andi a2, a2, SZREG-1  /* Update count */
> +
> +4:
> +	/* Handle trailing misalignment */
> +	beqz a2, 6f
> +	add a3, t0, a2
> +5:
> +	sb a1, 0(t0)
> +	addi t0, t0, 1
> +	bltu t0, a3, 5b
> +6:
> +	ret
> +END(__memset)
> --
> 2.31.0
>

Otherwise, LGTM.
Reviewed-by: Leo Yu-Chi Liang <ycliang at andestech.com>




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