From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> Subject: vga: optimise console scrolling Where possible, call memset16(), memmove() or memcpy() instead of using open-coded loops. I don't like the calling convention that uses a byte count instead of a count of u16s, but it's a little late to change that. Reduces code size of fbcon.o by almost 400 bytes on my laptop build. [akpm@xxxxxxxxxxxxxxxxxxxx: fix build] Link: http://lkml.kernel.org/r/20170720184539.31609-9-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Cc: David Miller <davem@xxxxxxxxxxxxx> Cc: Sam Ravnborg <sam@xxxxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: "James E.J. Bottomley" <jejb@xxxxxxxxxxxxxxxxxx> Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx> Cc: Matt Turner <mattst88@xxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Richard Henderson <rth@xxxxxxxxxxx> Cc: Russell King <rmk+kernel@xxxxxxxxxxxxxxx> Cc: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/mips/include/asm/vga.h | 7 +++++++ arch/powerpc/include/asm/vga.h | 8 ++++++++ arch/sparc/include/asm/vga.h | 25 +++++++++++++++++++++++++ include/linux/vt_buffer.h | 13 +++++++++++++ 4 files changed, 53 insertions(+) diff -puN arch/mips/include/asm/vga.h~vga-optimise-console-scrolling arch/mips/include/asm/vga.h --- a/arch/mips/include/asm/vga.h~vga-optimise-console-scrolling +++ a/arch/mips/include/asm/vga.h @@ -6,6 +6,7 @@ #ifndef _ASM_VGA_H #define _ASM_VGA_H +#include <linux/string.h> #include <asm/addrspace.h> #include <asm/byteorder.h> @@ -40,9 +41,15 @@ static inline u16 scr_readw(volatile con return le16_to_cpu(*addr); } +static inline void scr_memsetw(u16 *s, u16 v, unsigned int count) +{ + memset16(s, cpu_to_le16(v), count / 2); +} + #define scr_memcpyw(d, s, c) memcpy(d, s, c) #define scr_memmovew(d, s, c) memmove(d, s, c) #define VT_BUF_HAVE_MEMCPYW #define VT_BUF_HAVE_MEMMOVEW +#define VT_BUF_HAVE_MEMSETW #endif /* _ASM_VGA_H */ diff -puN arch/powerpc/include/asm/vga.h~vga-optimise-console-scrolling arch/powerpc/include/asm/vga.h --- a/arch/powerpc/include/asm/vga.h~vga-optimise-console-scrolling +++ a/arch/powerpc/include/asm/vga.h @@ -33,8 +33,16 @@ static inline u16 scr_readw(volatile con return le16_to_cpu(*addr); } +#define VT_BUF_HAVE_MEMSETW +static inline void scr_memsetw(u16 *s, u16 v, unsigned int n) +{ + memset16(s, cpu_to_le16(v), n / 2); +} + #define VT_BUF_HAVE_MEMCPYW +#define VT_BUF_HAVE_MEMMOVEW #define scr_memcpyw memcpy +#define scr_memmovew memmove #endif /* !CONFIG_VGA_CONSOLE && !CONFIG_MDA_CONSOLE */ diff -puN arch/sparc/include/asm/vga.h~vga-optimise-console-scrolling arch/sparc/include/asm/vga.h --- a/arch/sparc/include/asm/vga.h~vga-optimise-console-scrolling +++ a/arch/sparc/include/asm/vga.h @@ -8,9 +8,13 @@ #define _LINUX_ASM_VGA_H_ #include <linux/bug.h> +#include <linux/string.h> #include <asm/types.h> #define VT_BUF_HAVE_RW +#define VT_BUF_HAVE_MEMSETW +#define VT_BUF_HAVE_MEMCPYW +#define VT_BUF_HAVE_MEMMOVEW #undef scr_writew #undef scr_readw @@ -29,6 +33,27 @@ static inline u16 scr_readw(const u16 *a return *addr; } +static inline void scr_memsetw(u16 *p, u16 v, unsigned int n) +{ + BUG_ON((long) p >= 0); + + memset16(p, cpu_to_le16(v), n / 2); +} + +static inline void scr_memcpyw(u16 *d, u16 *s, unsigned int n) +{ + BUG_ON((long) d >= 0); + + memcpy(d, s, n); +} + +static inline void scr_memmovew(u16 *d, u16 *s, unsigned int n) +{ + BUG_ON((long) d >= 0); + + memmove(d, s, n); +} + #define VGA_MAP_MEM(x,s) (x) #endif diff -puN include/linux/vt_buffer.h~vga-optimise-console-scrolling include/linux/vt_buffer.h --- a/include/linux/vt_buffer.h~vga-optimise-console-scrolling +++ a/include/linux/vt_buffer.h @@ -13,6 +13,7 @@ #ifndef _LINUX_VT_BUFFER_H_ #define _LINUX_VT_BUFFER_H_ +#include <linux/string.h> #if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_MDA_CONSOLE) #include <asm/vga.h> @@ -26,24 +27,33 @@ #ifndef VT_BUF_HAVE_MEMSETW static inline void scr_memsetw(u16 *s, u16 c, unsigned int count) { +#ifdef VT_BUF_HAVE_RW count /= 2; while (count--) scr_writew(c, s++); +#else + memset16(s, c, count / 2); +#endif } #endif #ifndef VT_BUF_HAVE_MEMCPYW static inline void scr_memcpyw(u16 *d, const u16 *s, unsigned int count) { +#ifdef VT_BUF_HAVE_RW count /= 2; while (count--) scr_writew(scr_readw(s++), d++); +#else + memcpy(d, s, count); +#endif } #endif #ifndef VT_BUF_HAVE_MEMMOVEW static inline void scr_memmovew(u16 *d, const u16 *s, unsigned int count) { +#ifdef VT_BUF_HAVE_RW if (d < s) scr_memcpyw(d, s, count); else { @@ -53,6 +63,9 @@ static inline void scr_memmovew(u16 *d, while (count--) scr_writew(scr_readw(--s), --d); } +#else + memmove(d, s, count); +#endif } #endif _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
