72 lines
3.7 KiB
C
72 lines
3.7 KiB
C
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/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ This program is free software; you can redistribute it and/or modify │
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│ it under the terms of the GNU General Public License as published by │
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│ the Free Software Foundation; version 2 of the License. │
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│ │
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│ This program is distributed in the hope that it will be useful, but │
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│ WITHOUT ANY WARRANTY; without even the implied warranty of │
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│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
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│ General Public License for more details. │
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│ │
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│ You should have received a copy of the GNU General Public License │
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│ along with this program; if not, write to the Free Software │
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│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
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│ 02110-1301 USA │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "ape/lib/pc.h"
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#include "libc/dce.h"
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#include "libc/nexgen32e/nexgen32e.h"
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#include "libc/nt/struct/context.h"
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#include "libc/nt/thunk/msabi.h"
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#define kNtContextXstate 0x00100040
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#define kNtXstateAvx 2
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#define kNtXstateMaskAvx (1ull << kNtXstateAvx)
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static void EnableAvx(void) {
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asm volatile("mov\t%%cr4,%%rax\n\t"
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"or\t%0,%%rax\n\t"
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"mov\t%%rax,%%cr4\n\t"
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"xor\t%%ecx,%%ecx\n\t"
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"xgetbv\n\t"
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"or\t%1,%%eax\n\t"
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"xsetbv"
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: /* no outputs */
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: "i"(CR4_OSXSAVE), "i"(XCR0_X87 | XCR0_SSE | XCR0_AVX)
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: "rax", "rcx", "rdx", "memory", "cc");
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}
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static void EnableAvxOnWindows(void) {
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/* typedef uint64_t (*getenabledxstatefeatures_f)(void) __msabi; */
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/* typedef bool32 (*initializecontext_f)(void *buffer, uint32_t flags, */
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/* struct NtContext **out_context, */
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/* uint32_t *inout_buffersize) __msabi;
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*/
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/* typedef bool32 (*getxstatefeaturesmask_f)(struct NtContext * context, */
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/* uint64_t * out_featuremask)
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* __msabi; */
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/* typedef bool32 (*setxstatefeaturesmask_f)(struct NtContext * context, */
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/* uint64_t featuremask) __msabi; */
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/* getenabledxstatefeatures_f GetEnabledXStateFeatures; */
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/* initializecontext_f InitializeContext; */
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/* getxstatefeaturesmask_f GetXStateFeaturesMask; */
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/* setxstatefeaturesmask_f SetXStateFeaturesMask; */
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}
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/**
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* Requests authorization from operating system to do 256-bit math.
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* @assume avx cpuid check performed by caller
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*/
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int _init_enableavx(void) {
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if (IsMetal()) {
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EnableAvx();
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} else if (IsWindows()) {
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EnableAvxOnWindows();
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}
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return 0;
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}
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