cregit-Linux how code gets into the kernel

Release 4.14 arch/x86/lib/mmx_32.c

Directory: arch/x86/lib
// SPDX-License-Identifier: GPL-2.0
/*
 *      MMX 3DNow! library helper functions
 *
 *      To do:
 *      We can use MMX just for prefetch in IRQ's. This may be a win.
 *              (reported so on K6-III)
 *      We should use a better code neutral filler for the short jump
 *              leal ebx. [ebx] is apparently best for K6-2, but Cyrix ??
 *      We also want to clobber the filler register so we don't get any
 *              register forwarding stalls on the filler.
 *
 *      Add *user handling. Checksums are not a win with MMX on any CPU
 *      tested so far for any MMX solution figured.
 *
 *      22/09/2000 - Arjan van de Ven
 *              Improved for non-egineering-sample Athlons
 *
 */
#include <linux/hardirq.h>
#include <linux/string.h>
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/types.h>

#include <asm/fpu/api.h>
#include <asm/asm.h>


void *_mmx_memcpy(void *to, const void *from, size_t len) { void *p; int i; if (unlikely(in_interrupt())) return __memcpy(to, from, len); p = to; i = len >> 6; /* len/64 */ kernel_fpu_begin(); __asm__ __volatile__ ( "1: prefetch (%0)\n" /* This set is 28 bytes */ " prefetch 64(%0)\n" " prefetch 128(%0)\n" " prefetch 192(%0)\n" " prefetch 256(%0)\n" "2: \n" ".section .fixup, \"ax\"\n" "3: movw $0x1AEB, 1b\n" /* jmp on 26 bytes */ " jmp 2b\n" ".previous\n" _ASM_EXTABLE(1b, 3b) : : "r" (from)); for ( ; i > 5; i--) { __asm__ __volatile__ ( "1: prefetch 320(%0)\n" "2: movq (%0), %%mm0\n" " movq 8(%0), %%mm1\n" " movq 16(%0), %%mm2\n" " movq 24(%0), %%mm3\n" " movq %%mm0, (%1)\n" " movq %%mm1, 8(%1)\n" " movq %%mm2, 16(%1)\n" " movq %%mm3, 24(%1)\n" " movq 32(%0), %%mm0\n" " movq 40(%0), %%mm1\n" " movq 48(%0), %%mm2\n" " movq 56(%0), %%mm3\n" " movq %%mm0, 32(%1)\n" " movq %%mm1, 40(%1)\n" " movq %%mm2, 48(%1)\n" " movq %%mm3, 56(%1)\n" ".section .fixup, \"ax\"\n" "3: movw $0x05EB, 1b\n" /* jmp on 5 bytes */ " jmp 2b\n" ".previous\n" _ASM_EXTABLE(1b, 3b) : : "r" (from), "r" (to) : "memory"); from += 64; to += 64; } for ( ; i > 0; i--) { __asm__ __volatile__ ( " movq (%0), %%mm0\n" " movq 8(%0), %%mm1\n" " movq 16(%0), %%mm2\n" " movq 24(%0), %%mm3\n" " movq %%mm0, (%1)\n" " movq %%mm1, 8(%1)\n" " movq %%mm2, 16(%1)\n" " movq %%mm3, 24(%1)\n" " movq 32(%0), %%mm0\n" " movq 40(%0), %%mm1\n" " movq 48(%0), %%mm2\n" " movq 56(%0), %%mm3\n" " movq %%mm0, 32(%1)\n" " movq %%mm1, 40(%1)\n" " movq %%mm2, 48(%1)\n" " movq %%mm3, 56(%1)\n" : : "r" (from), "r" (to) : "memory"); from += 64; to += 64; } /* * Now do the tail of the block: */ __memcpy(to, from, len & 63); kernel_fpu_end(); return p; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)7557.69%116.67%
Dave Jones2620.00%233.33%
Linus Torvalds2519.23%233.33%
Ingo Molnar43.08%116.67%
Total130100.00%6100.00%

EXPORT_SYMBOL(_mmx_memcpy); #ifdef CONFIG_MK7 /* * The K7 has streaming cache bypass load/store. The Cyrix III, K6 and * other MMX using processors do not. */
static void fast_clear_page(void *page) { int i; kernel_fpu_begin(); __asm__ __volatile__ ( " pxor %%mm0, %%mm0\n" : : ); for (i = 0; i < 4096/64; i++) { __asm__ __volatile__ ( " movntq %%mm0, (%0)\n" " movntq %%mm0, 8(%0)\n" " movntq %%mm0, 16(%0)\n" " movntq %%mm0, 24(%0)\n" " movntq %%mm0, 32(%0)\n" " movntq %%mm0, 40(%0)\n" " movntq %%mm0, 48(%0)\n" " movntq %%mm0, 56(%0)\n" : : "r" (page) : "memory"); page += 64; } /* * Since movntq is weakly-ordered, a "sfence" is needed to become * ordered again: */ __asm__ __volatile__("sfence\n"::); kernel_fpu_end(); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)4692.00%360.00%
Linus Torvalds24.00%120.00%
Ingo Molnar24.00%120.00%
Total50100.00%5100.00%


static void fast_copy_page(void *to, void *from) { int i; kernel_fpu_begin(); /* * maybe the prefetch stuff can go before the expensive fnsave... * but that is for later. -AV */ __asm__ __volatile__( "1: prefetch (%0)\n" " prefetch 64(%0)\n" " prefetch 128(%0)\n" " prefetch 192(%0)\n" " prefetch 256(%0)\n" "2: \n" ".section .fixup, \"ax\"\n" "3: movw $0x1AEB, 1b\n" /* jmp on 26 bytes */ " jmp 2b\n" ".previous\n" _ASM_EXTABLE(1b, 3b) : : "r" (from)); for (i = 0; i < (4096-320)/64; i++) { __asm__ __volatile__ ( "1: prefetch 320(%0)\n" "2: movq (%0), %%mm0\n" " movntq %%mm0, (%1)\n" " movq 8(%0), %%mm1\n" " movntq %%mm1, 8(%1)\n" " movq 16(%0), %%mm2\n" " movntq %%mm2, 16(%1)\n" " movq 24(%0), %%mm3\n" " movntq %%mm3, 24(%1)\n" " movq 32(%0), %%mm4\n" " movntq %%mm4, 32(%1)\n" " movq 40(%0), %%mm5\n" " movntq %%mm5, 40(%1)\n" " movq 48(%0), %%mm6\n" " movntq %%mm6, 48(%1)\n" " movq 56(%0), %%mm7\n" " movntq %%mm7, 56(%1)\n" ".section .fixup, \"ax\"\n" "3: movw $0x05EB, 1b\n" /* jmp on 5 bytes */ " jmp 2b\n" ".previous\n" _ASM_EXTABLE(1b, 3b) : : "r" (from), "r" (to) : "memory"); from += 64; to += 64; } for (i = (4096-320)/64; i < 4096/64; i++) { __asm__ __volatile__ ( "2: movq (%0), %%mm0\n" " movntq %%mm0, (%1)\n" " movq 8(%0), %%mm1\n" " movntq %%mm1, 8(%1)\n" " movq 16(%0), %%mm2\n" " movntq %%mm2, 16(%1)\n" " movq 24(%0), %%mm3\n" " movntq %%mm3, 24(%1)\n" " movq 32(%0), %%mm4\n" " movntq %%mm4, 32(%1)\n" " movq 40(%0), %%mm5\n" " movntq %%mm5, 40(%1)\n" " movq 48(%0), %%mm6\n" " movntq %%mm6, 48(%1)\n" " movq 56(%0), %%mm7\n" " movntq %%mm7, 56(%1)\n" : : "r" (from), "r" (to) : "memory"); from += 64; to += 64; } /* * Since movntq is weakly-ordered, a "sfence" is needed to become * ordered again: */ __asm__ __volatile__("sfence \n"::); kernel_fpu_end(); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)5655.45%350.00%
Linus Torvalds3938.61%233.33%
Ingo Molnar65.94%116.67%
Total101100.00%6100.00%

#else /* CONFIG_MK7 */ /* * Generic MMX implementation without K7 specific streaming */
static void fast_clear_page(void *page) { int i; kernel_fpu_begin(); __asm__ __volatile__ ( " pxor %%mm0, %%mm0\n" : : ); for (i = 0; i < 4096/128; i++) { __asm__ __volatile__ ( " movq %%mm0, (%0)\n" " movq %%mm0, 8(%0)\n" " movq %%mm0, 16(%0)\n" " movq %%mm0, 24(%0)\n" " movq %%mm0, 32(%0)\n" " movq %%mm0, 40(%0)\n" " movq %%mm0, 48(%0)\n" " movq %%mm0, 56(%0)\n" " movq %%mm0, 64(%0)\n" " movq %%mm0, 72(%0)\n" " movq %%mm0, 80(%0)\n" " movq %%mm0, 88(%0)\n" " movq %%mm0, 96(%0)\n" " movq %%mm0, 104(%0)\n" " movq %%mm0, 112(%0)\n" " movq %%mm0, 120(%0)\n" : : "r" (page) : "memory"); page += 128; } kernel_fpu_end(); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds4597.83%266.67%
Ingo Molnar12.17%133.33%
Total46100.00%3100.00%


static void fast_copy_page(void *to, void *from) { int i; kernel_fpu_begin(); __asm__ __volatile__ ( "1: prefetch (%0)\n" " prefetch 64(%0)\n" " prefetch 128(%0)\n" " prefetch 192(%0)\n" " prefetch 256(%0)\n" "2: \n" ".section .fixup, \"ax\"\n" "3: movw $0x1AEB, 1b\n" /* jmp on 26 bytes */ " jmp 2b\n" ".previous\n" _ASM_EXTABLE(1b, 3b) : : "r" (from)); for (i = 0; i < 4096/64; i++) { __asm__ __volatile__ ( "1: prefetch 320(%0)\n" "2: movq (%0), %%mm0\n" " movq 8(%0), %%mm1\n" " movq 16(%0), %%mm2\n" " movq 24(%0), %%mm3\n" " movq %%mm0, (%1)\n" " movq %%mm1, 8(%1)\n" " movq %%mm2, 16(%1)\n" " movq %%mm3, 24(%1)\n" " movq 32(%0), %%mm0\n" " movq 40(%0), %%mm1\n" " movq 48(%0), %%mm2\n" " movq 56(%0), %%mm3\n" " movq %%mm0, 32(%1)\n" " movq %%mm1, 40(%1)\n" " movq %%mm2, 48(%1)\n" " movq %%mm3, 56(%1)\n" ".section .fixup, \"ax\"\n" "3: movw $0x05EB, 1b\n" /* jmp on 5 bytes */ " jmp 2b\n" ".previous\n" _ASM_EXTABLE(1b, 3b) : : "r" (from), "r" (to) : "memory"); from += 64; to += 64; } kernel_fpu_end(); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds5696.55%266.67%
Ingo Molnar23.45%133.33%
Total58100.00%3100.00%

#endif /* !CONFIG_MK7 */ /* * Favour MMX for page clear and copy: */
static void slow_zero_page(void *page) { int d0, d1; __asm__ __volatile__( "cld\n\t" "rep ; stosl" : "=&c" (d0), "=&D" (d1) :"a" (0), "1" (page), "0" (1024) :"memory"); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)1794.44%266.67%
Ingo Molnar15.56%133.33%
Total18100.00%3100.00%


void mmx_clear_page(void *page) { if (unlikely(in_interrupt())) slow_zero_page(page); else fast_clear_page(page); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)2589.29%266.67%
Dave Jones310.71%133.33%
Total28100.00%3100.00%

EXPORT_SYMBOL(mmx_clear_page);
static void slow_copy_page(void *to, void *from) { int d0, d1, d2; __asm__ __volatile__( "cld\n\t" "rep ; movsl" : "=&c" (d0), "=&D" (d1), "=&S" (d2) : "0" (1024), "1" ((long) to), "2" ((long) from) : "memory"); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)2395.83%266.67%
Ingo Molnar14.17%133.33%
Total24100.00%3100.00%


void mmx_copy_page(void *to, void *from) { if (unlikely(in_interrupt())) slow_copy_page(to, from); else fast_copy_page(to, from); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)3391.67%266.67%
Dave Jones38.33%133.33%
Total36100.00%3100.00%

EXPORT_SYMBOL(mmx_copy_page);

Overall Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)28252.13%320.00%
Linus Torvalds18033.27%426.67%
Ingo Molnar366.65%213.33%
Dave Jones325.91%213.33%
Alexey Dobriyan71.29%16.67%
H. Peter Anvin20.37%16.67%
Paul Gortmaker10.18%16.67%
Greg Kroah-Hartman10.18%16.67%
Total541100.00%15100.00%
Directory: arch/x86/lib
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.