-// 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-engineering-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>
-
-/*
- * Use KFPU_387. MMX instructions are not affected by MXCSR,
- * but both AMD and Intel documentation states that even integer MMX
- * operations will result in #MF if an exception is pending in FCW.
- *
- * EMMS is not needed afterwards because, after calling kernel_fpu_end(),
- * any subsequent user of the 387 stack will reinitialize it using
- * KFPU_387.
- */
-
-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_mask(KFPU_387);
-
- __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;
-}
-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_mask(KFPU_387);
-
- __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();
-}
-
-static void fast_copy_page(void *to, void *from)
-{
- int i;
-
- kernel_fpu_begin_mask(KFPU_387);
-
- /*
- * 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();
-}
-
-#else /* CONFIG_MK7 */
-
-/*
- * Generic MMX implementation without K7 specific streaming
- */
-static void fast_clear_page(void *page)
-{
- int i;
-
- kernel_fpu_begin_mask(KFPU_387);
-
- __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();
-}
-
-static void fast_copy_page(void *to, void *from)
-{
- int i;
-
- kernel_fpu_begin_mask(KFPU_387);
-
- __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();
-}
-
-#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");
-}
-
-void mmx_clear_page(void *page)
-{
- if (unlikely(in_interrupt()))
- slow_zero_page(page);
- else
- fast_clear_page(page);
-}
-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");
-}
-
-void mmx_copy_page(void *to, void *from)
-{
- if (unlikely(in_interrupt()))
- slow_copy_page(to, from);
- else
- fast_copy_page(to, from);
-}
-EXPORT_SYMBOL(mmx_copy_page);
projects / linux.git / commitdiff