| Message ID | 1475721740-15124-3-git-send-email-sjg@chromium.org |
|---|---|
| State | Accepted |
| Commit | a5b8722532729c62370b6abb278420804d5d071b |
| Delegated to: | Bin Meng |
| Headers | show |
Hi Simon, On Thu, Oct 6, 2016 at 10:42 AM, Simon Glass <sjg@chromium.org> wrote: > Bring in a faster memmove() from Linux 4.7. This speeds up scrolling on the > display. > > Signed-off-by: Simon Glass <sjg@chromium.org> > --- > > Changes in v2: > - Move the code into string.c > - Fix multi-line comments that should not be > > arch/x86/include/asm/string.h | 2 +- > arch/x86/lib/string.c | 161 ++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 162 insertions(+), 1 deletion(-) > Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested on Crown Bay with an external PCIe graphics card Tested-by: Bin Meng <bmeng.cn@gmail.com> However, I did not see significant speed up on screen scrolling... Regards, Bin
On Sat, Oct 8, 2016 at 10:25 AM, Bin Meng <bmeng.cn@gmail.com> wrote: > Hi Simon, > > On Thu, Oct 6, 2016 at 10:42 AM, Simon Glass <sjg@chromium.org> wrote: >> Bring in a faster memmove() from Linux 4.7. This speeds up scrolling on the >> display. >> >> Signed-off-by: Simon Glass <sjg@chromium.org> >> --- >> >> Changes in v2: >> - Move the code into string.c >> - Fix multi-line comments that should not be >> >> arch/x86/include/asm/string.h | 2 +- >> arch/x86/lib/string.c | 161 ++++++++++++++++++++++++++++++++++++++++++ >> 2 files changed, 162 insertions(+), 1 deletion(-) >> > > Reviewed-by: Bin Meng <bmeng.cn@gmail.com> > > Tested on Crown Bay with an external PCIe graphics card > Tested-by: Bin Meng <bmeng.cn@gmail.com> > > However, I did not see significant speed up on screen scrolling... > applied to u-boot-x86, thanks!
Hi Simon, On Sat, Oct 8, 2016 at 10:25 AM, Bin Meng <bmeng.cn@gmail.com> wrote: > Hi Simon, > > On Thu, Oct 6, 2016 at 10:42 AM, Simon Glass <sjg@chromium.org> wrote: >> Bring in a faster memmove() from Linux 4.7. This speeds up scrolling on the >> display. >> >> Signed-off-by: Simon Glass <sjg@chromium.org> >> --- >> >> Changes in v2: >> - Move the code into string.c >> - Fix multi-line comments that should not be >> >> arch/x86/include/asm/string.h | 2 +- >> arch/x86/lib/string.c | 161 ++++++++++++++++++++++++++++++++++++++++++ >> 2 files changed, 162 insertions(+), 1 deletion(-) >> > > Reviewed-by: Bin Meng <bmeng.cn@gmail.com> > > Tested on Crown Bay with an external PCIe graphics card > Tested-by: Bin Meng <bmeng.cn@gmail.com> > > However, I did not see significant speed up on screen scrolling... > Crown Bay is still using cfb_console.c, which is the legacy driver that does not use memmove(). Looks the new console_xxx driver is using memmove(). I guess I will need convert Crown Bay to use DM video. Regards, Bin
On Sat, Oct 8, 2016 at 1:53 PM, Bin Meng <bmeng.cn@gmail.com> wrote: > Hi Simon, > > On Sat, Oct 8, 2016 at 10:25 AM, Bin Meng <bmeng.cn@gmail.com> wrote: >> Hi Simon, >> >> On Thu, Oct 6, 2016 at 10:42 AM, Simon Glass <sjg@chromium.org> wrote: >>> Bring in a faster memmove() from Linux 4.7. This speeds up scrolling on the >>> display. >>> >>> Signed-off-by: Simon Glass <sjg@chromium.org> >>> --- >>> >>> Changes in v2: >>> - Move the code into string.c >>> - Fix multi-line comments that should not be >>> >>> arch/x86/include/asm/string.h | 2 +- >>> arch/x86/lib/string.c | 161 ++++++++++++++++++++++++++++++++++++++++++ >>> 2 files changed, 162 insertions(+), 1 deletion(-) >>> >> >> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> >> >> Tested on Crown Bay with an external PCIe graphics card >> Tested-by: Bin Meng <bmeng.cn@gmail.com> >> >> However, I did not see significant speed up on screen scrolling... >> > > Crown Bay is still using cfb_console.c, which is the legacy driver > that does not use memmove(). Looks the new console_xxx driver is using > memmove(). I guess I will need convert Crown Bay to use DM video. > Testing shows that on Crown Bay, the DM driver with the optimized memmove() does not improve the performance compared to legacy cfb_console driver. But on Bayleybay, memmove() indeed helps the screen scrolling. Regards, Bin
Hi Bin, On 9 October 2016 at 20:05, Bin Meng <bmeng.cn@gmail.com> wrote: > On Sat, Oct 8, 2016 at 1:53 PM, Bin Meng <bmeng.cn@gmail.com> wrote: >> Hi Simon, >> >> On Sat, Oct 8, 2016 at 10:25 AM, Bin Meng <bmeng.cn@gmail.com> wrote: >>> Hi Simon, >>> >>> On Thu, Oct 6, 2016 at 10:42 AM, Simon Glass <sjg@chromium.org> wrote: >>>> Bring in a faster memmove() from Linux 4.7. This speeds up scrolling on the >>>> display. >>>> >>>> Signed-off-by: Simon Glass <sjg@chromium.org> >>>> --- >>>> >>>> Changes in v2: >>>> - Move the code into string.c >>>> - Fix multi-line comments that should not be >>>> >>>> arch/x86/include/asm/string.h | 2 +- >>>> arch/x86/lib/string.c | 161 ++++++++++++++++++++++++++++++++++++++++++ >>>> 2 files changed, 162 insertions(+), 1 deletion(-) >>>> >>> >>> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> >>> >>> Tested on Crown Bay with an external PCIe graphics card >>> Tested-by: Bin Meng <bmeng.cn@gmail.com> >>> >>> However, I did not see significant speed up on screen scrolling... >>> >> >> Crown Bay is still using cfb_console.c, which is the legacy driver >> that does not use memmove(). Looks the new console_xxx driver is using >> memmove(). I guess I will need convert Crown Bay to use DM video. >> > > Testing shows that on Crown Bay, the DM driver with the optimized > memmove() does not improve the performance compared to legacy > cfb_console driver. But on Bayleybay, memmove() indeed helps the > screen scrolling. That's interesting. What is the difference between those two platforms? It is slow on Crown Bay? Regards, Simon
diff --git a/arch/x86/include/asm/string.h b/arch/x86/include/asm/string.h index 0ad612f..38afd23 100644 --- a/arch/x86/include/asm/string.h +++ b/arch/x86/include/asm/string.h @@ -17,7 +17,7 @@ extern char * strchr(const char * s, int c); #define __HAVE_ARCH_MEMCPY extern void * memcpy(void *, const void *, __kernel_size_t); -#undef __HAVE_ARCH_MEMMOVE +#define __HAVE_ARCH_MEMMOVE extern void * memmove(void *, const void *, __kernel_size_t); #undef __HAVE_ARCH_MEMCHR diff --git a/arch/x86/lib/string.c b/arch/x86/lib/string.c index 6c66431..5343c2b 100644 --- a/arch/x86/lib/string.c +++ b/arch/x86/lib/string.c @@ -130,3 +130,164 @@ void *memcpy(void *dstpp, const void *srcpp, size_t len) return dstpp; } + +void *memmove(void *dest, const void *src, size_t n) +{ + int d0, d1, d2, d3, d4, d5; + char *ret = dest; + + __asm__ __volatile__( + /* Handle more 16 bytes in loop */ + "cmp $0x10, %0\n\t" + "jb 1f\n\t" + + /* Decide forward/backward copy mode */ + "cmp %2, %1\n\t" + "jb 2f\n\t" + + /* + * movs instruction have many startup latency + * so we handle small size by general register. + */ + "cmp $680, %0\n\t" + "jb 3f\n\t" + /* movs instruction is only good for aligned case */ + "mov %1, %3\n\t" + "xor %2, %3\n\t" + "and $0xff, %3\n\t" + "jz 4f\n\t" + "3:\n\t" + "sub $0x10, %0\n\t" + + /* We gobble 16 bytes forward in each loop */ + "3:\n\t" + "sub $0x10, %0\n\t" + "mov 0*4(%1), %3\n\t" + "mov 1*4(%1), %4\n\t" + "mov %3, 0*4(%2)\n\t" + "mov %4, 1*4(%2)\n\t" + "mov 2*4(%1), %3\n\t" + "mov 3*4(%1), %4\n\t" + "mov %3, 2*4(%2)\n\t" + "mov %4, 3*4(%2)\n\t" + "lea 0x10(%1), %1\n\t" + "lea 0x10(%2), %2\n\t" + "jae 3b\n\t" + "add $0x10, %0\n\t" + "jmp 1f\n\t" + + /* Handle data forward by movs */ + ".p2align 4\n\t" + "4:\n\t" + "mov -4(%1, %0), %3\n\t" + "lea -4(%2, %0), %4\n\t" + "shr $2, %0\n\t" + "rep movsl\n\t" + "mov %3, (%4)\n\t" + "jmp 11f\n\t" + /* Handle data backward by movs */ + ".p2align 4\n\t" + "6:\n\t" + "mov (%1), %3\n\t" + "mov %2, %4\n\t" + "lea -4(%1, %0), %1\n\t" + "lea -4(%2, %0), %2\n\t" + "shr $2, %0\n\t" + "std\n\t" + "rep movsl\n\t" + "mov %3,(%4)\n\t" + "cld\n\t" + "jmp 11f\n\t" + + /* Start to prepare for backward copy */ + ".p2align 4\n\t" + "2:\n\t" + "cmp $680, %0\n\t" + "jb 5f\n\t" + "mov %1, %3\n\t" + "xor %2, %3\n\t" + "and $0xff, %3\n\t" + "jz 6b\n\t" + + /* Calculate copy position to tail */ + "5:\n\t" + "add %0, %1\n\t" + "add %0, %2\n\t" + "sub $0x10, %0\n\t" + + /* We gobble 16 bytes backward in each loop */ + "7:\n\t" + "sub $0x10, %0\n\t" + + "mov -1*4(%1), %3\n\t" + "mov -2*4(%1), %4\n\t" + "mov %3, -1*4(%2)\n\t" + "mov %4, -2*4(%2)\n\t" + "mov -3*4(%1), %3\n\t" + "mov -4*4(%1), %4\n\t" + "mov %3, -3*4(%2)\n\t" + "mov %4, -4*4(%2)\n\t" + "lea -0x10(%1), %1\n\t" + "lea -0x10(%2), %2\n\t" + "jae 7b\n\t" + /* Calculate copy position to head */ + "add $0x10, %0\n\t" + "sub %0, %1\n\t" + "sub %0, %2\n\t" + + /* Move data from 8 bytes to 15 bytes */ + ".p2align 4\n\t" + "1:\n\t" + "cmp $8, %0\n\t" + "jb 8f\n\t" + "mov 0*4(%1), %3\n\t" + "mov 1*4(%1), %4\n\t" + "mov -2*4(%1, %0), %5\n\t" + "mov -1*4(%1, %0), %1\n\t" + + "mov %3, 0*4(%2)\n\t" + "mov %4, 1*4(%2)\n\t" + "mov %5, -2*4(%2, %0)\n\t" + "mov %1, -1*4(%2, %0)\n\t" + "jmp 11f\n\t" + + /* Move data from 4 bytes to 7 bytes */ + ".p2align 4\n\t" + "8:\n\t" + "cmp $4, %0\n\t" + "jb 9f\n\t" + "mov 0*4(%1), %3\n\t" + "mov -1*4(%1, %0), %4\n\t" + "mov %3, 0*4(%2)\n\t" + "mov %4, -1*4(%2, %0)\n\t" + "jmp 11f\n\t" + + /* Move data from 2 bytes to 3 bytes */ + ".p2align 4\n\t" + "9:\n\t" + "cmp $2, %0\n\t" + "jb 10f\n\t" + "movw 0*2(%1), %%dx\n\t" + "movw -1*2(%1, %0), %%bx\n\t" + "movw %%dx, 0*2(%2)\n\t" + "movw %%bx, -1*2(%2, %0)\n\t" + "jmp 11f\n\t" + + /* Move data for 1 byte */ + ".p2align 4\n\t" + "10:\n\t" + "cmp $1, %0\n\t" + "jb 11f\n\t" + "movb (%1), %%cl\n\t" + "movb %%cl, (%2)\n\t" + ".p2align 4\n\t" + "11:" + : "=&c" (d0), "=&S" (d1), "=&D" (d2), + "=r" (d3), "=r" (d4), "=r"(d5) + : "0" (n), + "1" (src), + "2" (dest) + : "memory"); + + return ret; +}
Bring in a faster memmove() from Linux 4.7. This speeds up scrolling on the display. Signed-off-by: Simon Glass <sjg@chromium.org> --- Changes in v2: - Move the code into string.c - Fix multi-line comments that should not be arch/x86/include/asm/string.h | 2 +- arch/x86/lib/string.c | 161 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 162 insertions(+), 1 deletion(-)