diff --git a/sys/amd64/amd64/fpu.c b/sys/amd64/amd64/fpu.c index b9723266ea37..20e3dd34405d 100644 --- a/sys/amd64/amd64/fpu.c +++ b/sys/amd64/amd64/fpu.c @@ -1,1293 +1,1293 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1990 William Jolitz. * Copyright (c) 1991 The Regents of the University of California. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from: @(#)npx.c 7.2 (Berkeley) 5/12/91 */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Floating point support. */ #if defined(__GNUCLIKE_ASM) && !defined(lint) #define fldcw(cw) __asm __volatile("fldcw %0" : : "m" (cw)) #define fnclex() __asm __volatile("fnclex") #define fninit() __asm __volatile("fninit") #define fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr))) #define fnstsw(addr) __asm __volatile("fnstsw %0" : "=am" (*(addr))) #define fxrstor(addr) __asm __volatile("fxrstor %0" : : "m" (*(addr))) #define fxsave(addr) __asm __volatile("fxsave %0" : "=m" (*(addr))) #define ldmxcsr(csr) __asm __volatile("ldmxcsr %0" : : "m" (csr)) #define stmxcsr(addr) __asm __volatile("stmxcsr %0" : : "m" (*(addr))) static __inline void xrstor32(char *addr, uint64_t mask) { uint32_t low, hi; low = mask; hi = mask >> 32; __asm __volatile("xrstor %0" : : "m" (*addr), "a" (low), "d" (hi)); } static __inline void xrstor64(char *addr, uint64_t mask) { uint32_t low, hi; low = mask; hi = mask >> 32; __asm __volatile("xrstor64 %0" : : "m" (*addr), "a" (low), "d" (hi)); } static __inline void xsave32(char *addr, uint64_t mask) { uint32_t low, hi; low = mask; hi = mask >> 32; __asm __volatile("xsave %0" : "=m" (*addr) : "a" (low), "d" (hi) : "memory"); } static __inline void xsave64(char *addr, uint64_t mask) { uint32_t low, hi; low = mask; hi = mask >> 32; __asm __volatile("xsave64 %0" : "=m" (*addr) : "a" (low), "d" (hi) : "memory"); } static __inline void xsaveopt32(char *addr, uint64_t mask) { uint32_t low, hi; low = mask; hi = mask >> 32; __asm __volatile("xsaveopt %0" : "=m" (*addr) : "a" (low), "d" (hi) : "memory"); } static __inline void xsaveopt64(char *addr, uint64_t mask) { uint32_t low, hi; low = mask; hi = mask >> 32; __asm __volatile("xsaveopt64 %0" : "=m" (*addr) : "a" (low), "d" (hi) : "memory"); } #else /* !(__GNUCLIKE_ASM && !lint) */ void fldcw(u_short cw); void fnclex(void); void fninit(void); void fnstcw(caddr_t addr); void fnstsw(caddr_t addr); void fxsave(caddr_t addr); void fxrstor(caddr_t addr); void ldmxcsr(u_int csr); void stmxcsr(u_int *csr); void xrstor32(char *addr, uint64_t mask); void xrstor64(char *addr, uint64_t mask); void xsave32(char *addr, uint64_t mask); void xsave64(char *addr, uint64_t mask); void xsaveopt32(char *addr, uint64_t mask); void xsaveopt64(char *addr, uint64_t mask); #endif /* __GNUCLIKE_ASM && !lint */ #define start_emulating() load_cr0(rcr0() | CR0_TS) #define stop_emulating() clts() CTASSERT(sizeof(struct savefpu) == 512); CTASSERT(sizeof(struct xstate_hdr) == 64); CTASSERT(sizeof(struct savefpu_ymm) == 832); /* * This requirement is to make it easier for asm code to calculate * offset of the fpu save area from the pcb address. FPU save area * must be 64-byte aligned. */ CTASSERT(sizeof(struct pcb) % XSAVE_AREA_ALIGN == 0); /* * Ensure the copy of XCR0 saved in a core is contained in the padding * area. */ CTASSERT(X86_XSTATE_XCR0_OFFSET >= offsetof(struct savefpu, sv_pad) && X86_XSTATE_XCR0_OFFSET + sizeof(uint64_t) <= sizeof(struct savefpu)); static void fpu_clean_state(void); SYSCTL_INT(_hw, HW_FLOATINGPT, floatingpoint, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, 1, "Floating point instructions executed in hardware"); int use_xsave; /* non-static for cpu_switch.S */ uint64_t xsave_mask; /* the same */ static uma_zone_t fpu_save_area_zone; static struct savefpu *fpu_initialstate; static struct xsave_area_elm_descr { u_int offset; u_int size; } *xsave_area_desc; static void fpusave_xsaveopt64(void *addr) { xsaveopt64((char *)addr, xsave_mask); } static void fpusave_xsaveopt3264(void *addr) { if (SV_CURPROC_FLAG(SV_ILP32)) xsaveopt32((char *)addr, xsave_mask); else xsaveopt64((char *)addr, xsave_mask); } static void fpusave_xsave64(void *addr) { xsave64((char *)addr, xsave_mask); } static void fpusave_xsave3264(void *addr) { if (SV_CURPROC_FLAG(SV_ILP32)) xsave32((char *)addr, xsave_mask); else xsave64((char *)addr, xsave_mask); } static void fpurestore_xrstor64(void *addr) { xrstor64((char *)addr, xsave_mask); } static void fpurestore_xrstor3264(void *addr) { if (SV_CURPROC_FLAG(SV_ILP32)) xrstor32((char *)addr, xsave_mask); else xrstor64((char *)addr, xsave_mask); } static void fpusave_fxsave(void *addr) { fxsave((char *)addr); } static void fpurestore_fxrstor(void *addr) { fxrstor((char *)addr); } static void init_xsave(void) { if (use_xsave) return; if ((cpu_feature2 & CPUID2_XSAVE) == 0) return; use_xsave = 1; TUNABLE_INT_FETCH("hw.use_xsave", &use_xsave); } DEFINE_IFUNC(, void, fpusave, (void *)) { init_xsave(); if (!use_xsave) return (fpusave_fxsave); if ((cpu_stdext_feature & CPUID_EXTSTATE_XSAVEOPT) != 0) { return ((cpu_stdext_feature & CPUID_STDEXT_NFPUSG) != 0 ? fpusave_xsaveopt64 : fpusave_xsaveopt3264); } return ((cpu_stdext_feature & CPUID_STDEXT_NFPUSG) != 0 ? fpusave_xsave64 : fpusave_xsave3264); } DEFINE_IFUNC(, void, fpurestore, (void *)) { init_xsave(); if (!use_xsave) return (fpurestore_fxrstor); return ((cpu_stdext_feature & CPUID_STDEXT_NFPUSG) != 0 ? fpurestore_xrstor64 : fpurestore_xrstor3264); } void fpususpend(void *addr) { u_long cr0; cr0 = rcr0(); stop_emulating(); fpusave(addr); load_cr0(cr0); } void fpuresume(void *addr) { u_long cr0; cr0 = rcr0(); stop_emulating(); fninit(); if (use_xsave) load_xcr(XCR0, xsave_mask); fpurestore(addr); load_cr0(cr0); } /* * Enable XSAVE if supported and allowed by user. * Calculate the xsave_mask. */ static void fpuinit_bsp1(void) { u_int cp[4]; uint64_t xsave_mask_user; bool old_wp; if (!use_xsave) return; cpuid_count(0xd, 0x0, cp); xsave_mask = XFEATURE_ENABLED_X87 | XFEATURE_ENABLED_SSE; if ((cp[0] & xsave_mask) != xsave_mask) panic("CPU0 does not support X87 or SSE: %x", cp[0]); xsave_mask = ((uint64_t)cp[3] << 32) | cp[0]; xsave_mask_user = xsave_mask; TUNABLE_ULONG_FETCH("hw.xsave_mask", &xsave_mask_user); xsave_mask_user |= XFEATURE_ENABLED_X87 | XFEATURE_ENABLED_SSE; xsave_mask &= xsave_mask_user; if ((xsave_mask & XFEATURE_AVX512) != XFEATURE_AVX512) xsave_mask &= ~XFEATURE_AVX512; if ((xsave_mask & XFEATURE_MPX) != XFEATURE_MPX) xsave_mask &= ~XFEATURE_MPX; cpuid_count(0xd, 0x1, cp); if ((cp[0] & CPUID_EXTSTATE_XSAVEOPT) != 0) { /* * Patch the XSAVE instruction in the cpu_switch code * to XSAVEOPT. We assume that XSAVE encoding used * REX byte, and set the bit 4 of the r/m byte. * * It seems that some BIOSes give control to the OS * with CR0.WP already set, making the kernel text * read-only before cpu_startup(). */ old_wp = disable_wp(); ctx_switch_xsave32[3] |= 0x10; ctx_switch_xsave[3] |= 0x10; restore_wp(old_wp); } } /* * Calculate the fpu save area size. */ static void fpuinit_bsp2(void) { u_int cp[4]; if (use_xsave) { cpuid_count(0xd, 0x0, cp); cpu_max_ext_state_size = cp[1]; /* * Reload the cpu_feature2, since we enabled OSXSAVE. */ do_cpuid(1, cp); cpu_feature2 = cp[2]; } else cpu_max_ext_state_size = sizeof(struct savefpu); } /* * Initialize the floating point unit. */ void fpuinit(void) { register_t saveintr; u_int mxcsr; u_short control; if (IS_BSP()) fpuinit_bsp1(); if (use_xsave) { load_cr4(rcr4() | CR4_XSAVE); load_xcr(XCR0, xsave_mask); } /* * XCR0 shall be set up before CPU can report the save area size. */ if (IS_BSP()) fpuinit_bsp2(); /* * It is too early for critical_enter() to work on AP. */ saveintr = intr_disable(); stop_emulating(); fninit(); control = __INITIAL_FPUCW__; fldcw(control); mxcsr = __INITIAL_MXCSR__; ldmxcsr(mxcsr); start_emulating(); intr_restore(saveintr); } /* * On the boot CPU we generate a clean state that is used to * initialize the floating point unit when it is first used by a * process. */ static void fpuinitstate(void *arg __unused) { uint64_t *xstate_bv; register_t saveintr; int cp[4], i, max_ext_n; /* Do potentially blocking operations before disabling interrupts. */ fpu_save_area_zone = uma_zcreate("FPU_save_area", cpu_max_ext_state_size, NULL, NULL, NULL, NULL, XSAVE_AREA_ALIGN - 1, 0); fpu_initialstate = uma_zalloc(fpu_save_area_zone, M_WAITOK | M_ZERO); if (use_xsave) { max_ext_n = flsl(xsave_mask); xsave_area_desc = malloc(max_ext_n * sizeof(struct xsave_area_elm_descr), M_DEVBUF, M_WAITOK | M_ZERO); } saveintr = intr_disable(); stop_emulating(); fpusave_fxsave(fpu_initialstate); if (fpu_initialstate->sv_env.en_mxcsr_mask) cpu_mxcsr_mask = fpu_initialstate->sv_env.en_mxcsr_mask; else cpu_mxcsr_mask = 0xFFBF; /* * The fninit instruction does not modify XMM registers or x87 * registers (MM/ST). The fpusave call dumped the garbage * contained in the registers after reset to the initial state * saved. Clear XMM and x87 registers file image to make the * startup program state and signal handler XMM/x87 register * content predictable. */ bzero(fpu_initialstate->sv_fp, sizeof(fpu_initialstate->sv_fp)); bzero(fpu_initialstate->sv_xmm, sizeof(fpu_initialstate->sv_xmm)); /* * Create a table describing the layout of the CPU Extended * Save Area. */ if (use_xsave) { xstate_bv = (uint64_t *)((char *)(fpu_initialstate + 1) + offsetof(struct xstate_hdr, xstate_bv)); *xstate_bv = XFEATURE_ENABLED_X87 | XFEATURE_ENABLED_SSE; /* x87 state */ xsave_area_desc[0].offset = 0; xsave_area_desc[0].size = 160; /* XMM */ xsave_area_desc[1].offset = 160; xsave_area_desc[1].size = 288 - 160; for (i = 2; i < max_ext_n; i++) { cpuid_count(0xd, i, cp); xsave_area_desc[i].offset = cp[1]; xsave_area_desc[i].size = cp[0]; } } start_emulating(); intr_restore(saveintr); } /* EFIRT needs this to be initialized before we can enter our EFI environment */ -SYSINIT(fpuinitstate, SI_SUB_DRIVERS, SI_ORDER_FIRST, fpuinitstate, NULL); +SYSINIT(fpuinitstate, SI_SUB_CPU, SI_ORDER_ANY, fpuinitstate, NULL); /* * Free coprocessor (if we have it). */ void fpuexit(struct thread *td) { critical_enter(); if (curthread == PCPU_GET(fpcurthread)) { stop_emulating(); fpusave(curpcb->pcb_save); start_emulating(); PCPU_SET(fpcurthread, NULL); } critical_exit(); } int fpuformat(void) { return (_MC_FPFMT_XMM); } /* * The following mechanism is used to ensure that the FPE_... value * that is passed as a trapcode to the signal handler of the user * process does not have more than one bit set. * * Multiple bits may be set if the user process modifies the control * word while a status word bit is already set. While this is a sign * of bad coding, we have no choise than to narrow them down to one * bit, since we must not send a trapcode that is not exactly one of * the FPE_ macros. * * The mechanism has a static table with 127 entries. Each combination * of the 7 FPU status word exception bits directly translates to a * position in this table, where a single FPE_... value is stored. * This FPE_... value stored there is considered the "most important" * of the exception bits and will be sent as the signal code. The * precedence of the bits is based upon Intel Document "Numerical * Applications", Chapter "Special Computational Situations". * * The macro to choose one of these values does these steps: 1) Throw * away status word bits that cannot be masked. 2) Throw away the bits * currently masked in the control word, assuming the user isn't * interested in them anymore. 3) Reinsert status word bit 7 (stack * fault) if it is set, which cannot be masked but must be presered. * 4) Use the remaining bits to point into the trapcode table. * * The 6 maskable bits in order of their preference, as stated in the * above referenced Intel manual: * 1 Invalid operation (FP_X_INV) * 1a Stack underflow * 1b Stack overflow * 1c Operand of unsupported format * 1d SNaN operand. * 2 QNaN operand (not an exception, irrelavant here) * 3 Any other invalid-operation not mentioned above or zero divide * (FP_X_INV, FP_X_DZ) * 4 Denormal operand (FP_X_DNML) * 5 Numeric over/underflow (FP_X_OFL, FP_X_UFL) * 6 Inexact result (FP_X_IMP) */ static char fpetable[128] = { 0, FPE_FLTINV, /* 1 - INV */ FPE_FLTUND, /* 2 - DNML */ FPE_FLTINV, /* 3 - INV | DNML */ FPE_FLTDIV, /* 4 - DZ */ FPE_FLTINV, /* 5 - INV | DZ */ FPE_FLTDIV, /* 6 - DNML | DZ */ FPE_FLTINV, /* 7 - INV | DNML | DZ */ FPE_FLTOVF, /* 8 - OFL */ FPE_FLTINV, /* 9 - INV | OFL */ FPE_FLTUND, /* A - DNML | OFL */ FPE_FLTINV, /* B - INV | DNML | OFL */ FPE_FLTDIV, /* C - DZ | OFL */ FPE_FLTINV, /* D - INV | DZ | OFL */ FPE_FLTDIV, /* E - DNML | DZ | OFL */ FPE_FLTINV, /* F - INV | DNML | DZ | OFL */ FPE_FLTUND, /* 10 - UFL */ FPE_FLTINV, /* 11 - INV | UFL */ FPE_FLTUND, /* 12 - DNML | UFL */ FPE_FLTINV, /* 13 - INV | DNML | UFL */ FPE_FLTDIV, /* 14 - DZ | UFL */ FPE_FLTINV, /* 15 - INV | DZ | UFL */ FPE_FLTDIV, /* 16 - DNML | DZ | UFL */ FPE_FLTINV, /* 17 - INV | DNML | DZ | UFL */ FPE_FLTOVF, /* 18 - OFL | UFL */ FPE_FLTINV, /* 19 - INV | OFL | UFL */ FPE_FLTUND, /* 1A - DNML | OFL | UFL */ FPE_FLTINV, /* 1B - INV | DNML | OFL | UFL */ FPE_FLTDIV, /* 1C - DZ | OFL | UFL */ FPE_FLTINV, /* 1D - INV | DZ | OFL | UFL */ FPE_FLTDIV, /* 1E - DNML | DZ | OFL | UFL */ FPE_FLTINV, /* 1F - INV | DNML | DZ | OFL | UFL */ FPE_FLTRES, /* 20 - IMP */ FPE_FLTINV, /* 21 - INV | IMP */ FPE_FLTUND, /* 22 - DNML | IMP */ FPE_FLTINV, /* 23 - INV | DNML | IMP */ FPE_FLTDIV, /* 24 - DZ | IMP */ FPE_FLTINV, /* 25 - INV | DZ | IMP */ FPE_FLTDIV, /* 26 - DNML | DZ | IMP */ FPE_FLTINV, /* 27 - INV | DNML | DZ | IMP */ FPE_FLTOVF, /* 28 - OFL | IMP */ FPE_FLTINV, /* 29 - INV | OFL | IMP */ FPE_FLTUND, /* 2A - DNML | OFL | IMP */ FPE_FLTINV, /* 2B - INV | DNML | OFL | IMP */ FPE_FLTDIV, /* 2C - DZ | OFL | IMP */ FPE_FLTINV, /* 2D - INV | DZ | OFL | IMP */ FPE_FLTDIV, /* 2E - DNML | DZ | OFL | IMP */ FPE_FLTINV, /* 2F - INV | DNML | DZ | OFL | IMP */ FPE_FLTUND, /* 30 - UFL | IMP */ FPE_FLTINV, /* 31 - INV | UFL | IMP */ FPE_FLTUND, /* 32 - DNML | UFL | IMP */ FPE_FLTINV, /* 33 - INV | DNML | UFL | IMP */ FPE_FLTDIV, /* 34 - DZ | UFL | IMP */ FPE_FLTINV, /* 35 - INV | DZ | UFL | IMP */ FPE_FLTDIV, /* 36 - DNML | DZ | UFL | IMP */ FPE_FLTINV, /* 37 - INV | DNML | DZ | UFL | IMP */ FPE_FLTOVF, /* 38 - OFL | UFL | IMP */ FPE_FLTINV, /* 39 - INV | OFL | UFL | IMP */ FPE_FLTUND, /* 3A - DNML | OFL | UFL | IMP */ FPE_FLTINV, /* 3B - INV | DNML | OFL | UFL | IMP */ FPE_FLTDIV, /* 3C - DZ | OFL | UFL | IMP */ FPE_FLTINV, /* 3D - INV | DZ | OFL | UFL | IMP */ FPE_FLTDIV, /* 3E - DNML | DZ | OFL | UFL | IMP */ FPE_FLTINV, /* 3F - INV | DNML | DZ | OFL | UFL | IMP */ FPE_FLTSUB, /* 40 - STK */ FPE_FLTSUB, /* 41 - INV | STK */ FPE_FLTUND, /* 42 - DNML | STK */ FPE_FLTSUB, /* 43 - INV | DNML | STK */ FPE_FLTDIV, /* 44 - DZ | STK */ FPE_FLTSUB, /* 45 - INV | DZ | STK */ FPE_FLTDIV, /* 46 - DNML | DZ | STK */ FPE_FLTSUB, /* 47 - INV | DNML | DZ | STK */ FPE_FLTOVF, /* 48 - OFL | STK */ FPE_FLTSUB, /* 49 - INV | OFL | STK */ FPE_FLTUND, /* 4A - DNML | OFL | STK */ FPE_FLTSUB, /* 4B - INV | DNML | OFL | STK */ FPE_FLTDIV, /* 4C - DZ | OFL | STK */ FPE_FLTSUB, /* 4D - INV | DZ | OFL | STK */ FPE_FLTDIV, /* 4E - DNML | DZ | OFL | STK */ FPE_FLTSUB, /* 4F - INV | DNML | DZ | OFL | STK */ FPE_FLTUND, /* 50 - UFL | STK */ FPE_FLTSUB, /* 51 - INV | UFL | STK */ FPE_FLTUND, /* 52 - DNML | UFL | STK */ FPE_FLTSUB, /* 53 - INV | DNML | UFL | STK */ FPE_FLTDIV, /* 54 - DZ | UFL | STK */ FPE_FLTSUB, /* 55 - INV | DZ | UFL | STK */ FPE_FLTDIV, /* 56 - DNML | DZ | UFL | STK */ FPE_FLTSUB, /* 57 - INV | DNML | DZ | UFL | STK */ FPE_FLTOVF, /* 58 - OFL | UFL | STK */ FPE_FLTSUB, /* 59 - INV | OFL | UFL | STK */ FPE_FLTUND, /* 5A - DNML | OFL | UFL | STK */ FPE_FLTSUB, /* 5B - INV | DNML | OFL | UFL | STK */ FPE_FLTDIV, /* 5C - DZ | OFL | UFL | STK */ FPE_FLTSUB, /* 5D - INV | DZ | OFL | UFL | STK */ FPE_FLTDIV, /* 5E - DNML | DZ | OFL | UFL | STK */ FPE_FLTSUB, /* 5F - INV | DNML | DZ | OFL | UFL | STK */ FPE_FLTRES, /* 60 - IMP | STK */ FPE_FLTSUB, /* 61 - INV | IMP | STK */ FPE_FLTUND, /* 62 - DNML | IMP | STK */ FPE_FLTSUB, /* 63 - INV | DNML | IMP | STK */ FPE_FLTDIV, /* 64 - DZ | IMP | STK */ FPE_FLTSUB, /* 65 - INV | DZ | IMP | STK */ FPE_FLTDIV, /* 66 - DNML | DZ | IMP | STK */ FPE_FLTSUB, /* 67 - INV | DNML | DZ | IMP | STK */ FPE_FLTOVF, /* 68 - OFL | IMP | STK */ FPE_FLTSUB, /* 69 - INV | OFL | IMP | STK */ FPE_FLTUND, /* 6A - DNML | OFL | IMP | STK */ FPE_FLTSUB, /* 6B - INV | DNML | OFL | IMP | STK */ FPE_FLTDIV, /* 6C - DZ | OFL | IMP | STK */ FPE_FLTSUB, /* 6D - INV | DZ | OFL | IMP | STK */ FPE_FLTDIV, /* 6E - DNML | DZ | OFL | IMP | STK */ FPE_FLTSUB, /* 6F - INV | DNML | DZ | OFL | IMP | STK */ FPE_FLTUND, /* 70 - UFL | IMP | STK */ FPE_FLTSUB, /* 71 - INV | UFL | IMP | STK */ FPE_FLTUND, /* 72 - DNML | UFL | IMP | STK */ FPE_FLTSUB, /* 73 - INV | DNML | UFL | IMP | STK */ FPE_FLTDIV, /* 74 - DZ | UFL | IMP | STK */ FPE_FLTSUB, /* 75 - INV | DZ | UFL | IMP | STK */ FPE_FLTDIV, /* 76 - DNML | DZ | UFL | IMP | STK */ FPE_FLTSUB, /* 77 - INV | DNML | DZ | UFL | IMP | STK */ FPE_FLTOVF, /* 78 - OFL | UFL | IMP | STK */ FPE_FLTSUB, /* 79 - INV | OFL | UFL | IMP | STK */ FPE_FLTUND, /* 7A - DNML | OFL | UFL | IMP | STK */ FPE_FLTSUB, /* 7B - INV | DNML | OFL | UFL | IMP | STK */ FPE_FLTDIV, /* 7C - DZ | OFL | UFL | IMP | STK */ FPE_FLTSUB, /* 7D - INV | DZ | OFL | UFL | IMP | STK */ FPE_FLTDIV, /* 7E - DNML | DZ | OFL | UFL | IMP | STK */ FPE_FLTSUB, /* 7F - INV | DNML | DZ | OFL | UFL | IMP | STK */ }; /* * Read the FP status and control words, then generate si_code value * for SIGFPE. The error code chosen will be one of the * FPE_... macros. It will be sent as the second argument to old * BSD-style signal handlers and as "siginfo_t->si_code" (second * argument) to SA_SIGINFO signal handlers. * * Some time ago, we cleared the x87 exceptions with FNCLEX there. * Clearing exceptions was necessary mainly to avoid IRQ13 bugs. The * usermode code which understands the FPU hardware enough to enable * the exceptions, can also handle clearing the exception state in the * handler. The only consequence of not clearing the exception is the * rethrow of the SIGFPE on return from the signal handler and * reexecution of the corresponding instruction. * * For XMM traps, the exceptions were never cleared. */ int fputrap_x87(void) { struct savefpu *pcb_save; u_short control, status; critical_enter(); /* * Interrupt handling (for another interrupt) may have pushed the * state to memory. Fetch the relevant parts of the state from * wherever they are. */ if (PCPU_GET(fpcurthread) != curthread) { pcb_save = curpcb->pcb_save; control = pcb_save->sv_env.en_cw; status = pcb_save->sv_env.en_sw; } else { fnstcw(&control); fnstsw(&status); } critical_exit(); return (fpetable[status & ((~control & 0x3f) | 0x40)]); } int fputrap_sse(void) { u_int mxcsr; critical_enter(); if (PCPU_GET(fpcurthread) != curthread) mxcsr = curpcb->pcb_save->sv_env.en_mxcsr; else stmxcsr(&mxcsr); critical_exit(); return (fpetable[(mxcsr & (~mxcsr >> 7)) & 0x3f]); } static void restore_fpu_curthread(struct thread *td) { struct pcb *pcb; /* * Record new context early in case frstor causes a trap. */ PCPU_SET(fpcurthread, td); stop_emulating(); fpu_clean_state(); pcb = td->td_pcb; if ((pcb->pcb_flags & PCB_FPUINITDONE) == 0) { /* * This is the first time this thread has used the FPU or * the PCB doesn't contain a clean FPU state. Explicitly * load an initial state. * * We prefer to restore the state from the actual save * area in PCB instead of directly loading from * fpu_initialstate, to ignite the XSAVEOPT * tracking engine. */ bcopy(fpu_initialstate, pcb->pcb_save, cpu_max_ext_state_size); fpurestore(pcb->pcb_save); if (pcb->pcb_initial_fpucw != __INITIAL_FPUCW__) fldcw(pcb->pcb_initial_fpucw); if (PCB_USER_FPU(pcb)) set_pcb_flags(pcb, PCB_FPUINITDONE | PCB_USERFPUINITDONE); else set_pcb_flags(pcb, PCB_FPUINITDONE); } else fpurestore(pcb->pcb_save); } /* * Device Not Available (DNA, #NM) exception handler. * * It would be better to switch FP context here (if curthread != * fpcurthread) and not necessarily for every context switch, but it * is too hard to access foreign pcb's. */ void fpudna(void) { struct thread *td; td = curthread; /* * This handler is entered with interrupts enabled, so context * switches may occur before critical_enter() is executed. If * a context switch occurs, then when we regain control, our * state will have been completely restored. The CPU may * change underneath us, but the only part of our context that * lives in the CPU is CR0.TS and that will be "restored" by * setting it on the new CPU. */ critical_enter(); KASSERT((curpcb->pcb_flags & PCB_FPUNOSAVE) == 0, ("fpudna while in fpu_kern_enter(FPU_KERN_NOCTX)")); if (__predict_false(PCPU_GET(fpcurthread) == td)) { /* * Some virtual machines seems to set %cr0.TS at * arbitrary moments. Silently clear the TS bit * regardless of the eager/lazy FPU context switch * mode. */ stop_emulating(); } else { if (__predict_false(PCPU_GET(fpcurthread) != NULL)) { panic( "fpudna: fpcurthread = %p (%d), curthread = %p (%d)\n", PCPU_GET(fpcurthread), PCPU_GET(fpcurthread)->td_tid, td, td->td_tid); } restore_fpu_curthread(td); } critical_exit(); } void fpu_activate_sw(struct thread *td); /* Called from the context switch */ void fpu_activate_sw(struct thread *td) { if ((td->td_pflags & TDP_KTHREAD) != 0 || !PCB_USER_FPU(td->td_pcb)) { PCPU_SET(fpcurthread, NULL); start_emulating(); } else if (PCPU_GET(fpcurthread) != td) { restore_fpu_curthread(td); } } void fpudrop(void) { struct thread *td; td = PCPU_GET(fpcurthread); KASSERT(td == curthread, ("fpudrop: fpcurthread != curthread")); CRITICAL_ASSERT(td); PCPU_SET(fpcurthread, NULL); clear_pcb_flags(td->td_pcb, PCB_FPUINITDONE); start_emulating(); } /* * Get the user state of the FPU into pcb->pcb_user_save without * dropping ownership (if possible). It returns the FPU ownership * status. */ int fpugetregs(struct thread *td) { struct pcb *pcb; uint64_t *xstate_bv, bit; char *sa; int max_ext_n, i, owned; pcb = td->td_pcb; critical_enter(); if ((pcb->pcb_flags & PCB_USERFPUINITDONE) == 0) { bcopy(fpu_initialstate, get_pcb_user_save_pcb(pcb), cpu_max_ext_state_size); get_pcb_user_save_pcb(pcb)->sv_env.en_cw = pcb->pcb_initial_fpucw; fpuuserinited(td); critical_exit(); return (_MC_FPOWNED_PCB); } if (td == PCPU_GET(fpcurthread) && PCB_USER_FPU(pcb)) { fpusave(get_pcb_user_save_pcb(pcb)); owned = _MC_FPOWNED_FPU; } else { owned = _MC_FPOWNED_PCB; } if (use_xsave) { /* * Handle partially saved state. */ sa = (char *)get_pcb_user_save_pcb(pcb); xstate_bv = (uint64_t *)(sa + sizeof(struct savefpu) + offsetof(struct xstate_hdr, xstate_bv)); max_ext_n = flsl(xsave_mask); for (i = 0; i < max_ext_n; i++) { bit = 1ULL << i; if ((xsave_mask & bit) == 0 || (*xstate_bv & bit) != 0) continue; bcopy((char *)fpu_initialstate + xsave_area_desc[i].offset, sa + xsave_area_desc[i].offset, xsave_area_desc[i].size); *xstate_bv |= bit; } } critical_exit(); return (owned); } void fpuuserinited(struct thread *td) { struct pcb *pcb; CRITICAL_ASSERT(td); pcb = td->td_pcb; if (PCB_USER_FPU(pcb)) set_pcb_flags(pcb, PCB_FPUINITDONE | PCB_USERFPUINITDONE); else set_pcb_flags(pcb, PCB_FPUINITDONE); } int fpusetxstate(struct thread *td, char *xfpustate, size_t xfpustate_size) { struct xstate_hdr *hdr, *ehdr; size_t len, max_len; uint64_t bv; /* XXXKIB should we clear all extended state in xstate_bv instead ? */ if (xfpustate == NULL) return (0); if (!use_xsave) return (EOPNOTSUPP); len = xfpustate_size; if (len < sizeof(struct xstate_hdr)) return (EINVAL); max_len = cpu_max_ext_state_size - sizeof(struct savefpu); if (len > max_len) return (EINVAL); ehdr = (struct xstate_hdr *)xfpustate; bv = ehdr->xstate_bv; /* * Avoid #gp. */ if (bv & ~xsave_mask) return (EINVAL); hdr = (struct xstate_hdr *)(get_pcb_user_save_td(td) + 1); hdr->xstate_bv = bv; bcopy(xfpustate + sizeof(struct xstate_hdr), (char *)(hdr + 1), len - sizeof(struct xstate_hdr)); return (0); } /* * Set the state of the FPU. */ int fpusetregs(struct thread *td, struct savefpu *addr, char *xfpustate, size_t xfpustate_size) { struct pcb *pcb; int error; addr->sv_env.en_mxcsr &= cpu_mxcsr_mask; pcb = td->td_pcb; error = 0; critical_enter(); if (td == PCPU_GET(fpcurthread) && PCB_USER_FPU(pcb)) { error = fpusetxstate(td, xfpustate, xfpustate_size); if (error == 0) { bcopy(addr, get_pcb_user_save_td(td), sizeof(*addr)); fpurestore(get_pcb_user_save_td(td)); set_pcb_flags(pcb, PCB_FPUINITDONE | PCB_USERFPUINITDONE); } } else { error = fpusetxstate(td, xfpustate, xfpustate_size); if (error == 0) { bcopy(addr, get_pcb_user_save_td(td), sizeof(*addr)); fpuuserinited(td); } } critical_exit(); return (error); } /* * On AuthenticAMD processors, the fxrstor instruction does not restore * the x87's stored last instruction pointer, last data pointer, and last * opcode values, except in the rare case in which the exception summary * (ES) bit in the x87 status word is set to 1. * * In order to avoid leaking this information across processes, we clean * these values by performing a dummy load before executing fxrstor(). */ static void fpu_clean_state(void) { static float dummy_variable = 0.0; u_short status; /* * Clear the ES bit in the x87 status word if it is currently * set, in order to avoid causing a fault in the upcoming load. */ fnstsw(&status); if (status & 0x80) fnclex(); /* * Load the dummy variable into the x87 stack. This mangles * the x87 stack, but we don't care since we're about to call * fxrstor() anyway. */ __asm __volatile("ffree %%st(7); flds %0" : : "m" (dummy_variable)); } /* * This really sucks. We want the acpi version only, but it requires * the isa_if.h file in order to get the definitions. */ #include "opt_isa.h" #ifdef DEV_ISA #include /* * This sucks up the legacy ISA support assignments from PNPBIOS/ACPI. */ static struct isa_pnp_id fpupnp_ids[] = { { 0x040cd041, "Legacy ISA coprocessor support" }, /* PNP0C04 */ { 0 } }; static int fpupnp_probe(device_t dev) { int result; result = ISA_PNP_PROBE(device_get_parent(dev), dev, fpupnp_ids); if (result <= 0) device_quiet(dev); return (result); } static int fpupnp_attach(device_t dev) { return (0); } static device_method_t fpupnp_methods[] = { /* Device interface */ DEVMETHOD(device_probe, fpupnp_probe), DEVMETHOD(device_attach, fpupnp_attach), DEVMETHOD(device_detach, bus_generic_detach), DEVMETHOD(device_shutdown, bus_generic_shutdown), DEVMETHOD(device_suspend, bus_generic_suspend), DEVMETHOD(device_resume, bus_generic_resume), { 0, 0 } }; static driver_t fpupnp_driver = { "fpupnp", fpupnp_methods, 1, /* no softc */ }; static devclass_t fpupnp_devclass; DRIVER_MODULE(fpupnp, acpi, fpupnp_driver, fpupnp_devclass, 0, 0); ISA_PNP_INFO(fpupnp_ids); #endif /* DEV_ISA */ static MALLOC_DEFINE(M_FPUKERN_CTX, "fpukern_ctx", "Kernel contexts for FPU state"); #define FPU_KERN_CTX_FPUINITDONE 0x01 #define FPU_KERN_CTX_DUMMY 0x02 /* avoided save for the kern thread */ #define FPU_KERN_CTX_INUSE 0x04 struct fpu_kern_ctx { struct savefpu *prev; uint32_t flags; char hwstate1[]; }; static inline size_t __pure2 fpu_kern_alloc_sz(u_int max_est) { return (sizeof(struct fpu_kern_ctx) + XSAVE_AREA_ALIGN + max_est); } static inline int __pure2 fpu_kern_malloc_flags(u_int fpflags) { return (((fpflags & FPU_KERN_NOWAIT) ? M_NOWAIT : M_WAITOK) | M_ZERO); } struct fpu_kern_ctx * fpu_kern_alloc_ctx_domain(int domain, u_int flags) { return (malloc_domainset(fpu_kern_alloc_sz(cpu_max_ext_state_size), M_FPUKERN_CTX, DOMAINSET_PREF(domain), fpu_kern_malloc_flags(flags))); } struct fpu_kern_ctx * fpu_kern_alloc_ctx(u_int flags) { return (malloc(fpu_kern_alloc_sz(cpu_max_ext_state_size), M_FPUKERN_CTX, fpu_kern_malloc_flags(flags))); } void fpu_kern_free_ctx(struct fpu_kern_ctx *ctx) { KASSERT((ctx->flags & FPU_KERN_CTX_INUSE) == 0, ("free'ing inuse ctx")); /* XXXKIB clear the memory ? */ free(ctx, M_FPUKERN_CTX); } static struct savefpu * fpu_kern_ctx_savefpu(struct fpu_kern_ctx *ctx) { vm_offset_t p; p = (vm_offset_t)&ctx->hwstate1; p = roundup2(p, XSAVE_AREA_ALIGN); return ((struct savefpu *)p); } void fpu_kern_enter(struct thread *td, struct fpu_kern_ctx *ctx, u_int flags) { struct pcb *pcb; pcb = td->td_pcb; KASSERT((flags & FPU_KERN_NOCTX) != 0 || ctx != NULL, ("ctx is required when !FPU_KERN_NOCTX")); KASSERT(ctx == NULL || (ctx->flags & FPU_KERN_CTX_INUSE) == 0, ("using inuse ctx")); KASSERT((pcb->pcb_flags & PCB_FPUNOSAVE) == 0, ("recursive fpu_kern_enter while in PCB_FPUNOSAVE state")); if ((flags & FPU_KERN_NOCTX) != 0) { critical_enter(); stop_emulating(); if (curthread == PCPU_GET(fpcurthread)) { fpusave(curpcb->pcb_save); PCPU_SET(fpcurthread, NULL); } else { KASSERT(PCPU_GET(fpcurthread) == NULL, ("invalid fpcurthread")); } /* * This breaks XSAVEOPT tracker, but * PCB_FPUNOSAVE state is supposed to never need to * save FPU context at all. */ fpurestore(fpu_initialstate); set_pcb_flags(pcb, PCB_KERNFPU | PCB_FPUNOSAVE | PCB_FPUINITDONE); return; } if ((flags & FPU_KERN_KTHR) != 0 && is_fpu_kern_thread(0)) { ctx->flags = FPU_KERN_CTX_DUMMY | FPU_KERN_CTX_INUSE; return; } critical_enter(); KASSERT(!PCB_USER_FPU(pcb) || pcb->pcb_save == get_pcb_user_save_pcb(pcb), ("mangled pcb_save")); ctx->flags = FPU_KERN_CTX_INUSE; if ((pcb->pcb_flags & PCB_FPUINITDONE) != 0) ctx->flags |= FPU_KERN_CTX_FPUINITDONE; fpuexit(td); ctx->prev = pcb->pcb_save; pcb->pcb_save = fpu_kern_ctx_savefpu(ctx); set_pcb_flags(pcb, PCB_KERNFPU); clear_pcb_flags(pcb, PCB_FPUINITDONE); critical_exit(); } int fpu_kern_leave(struct thread *td, struct fpu_kern_ctx *ctx) { struct pcb *pcb; pcb = td->td_pcb; if ((pcb->pcb_flags & PCB_FPUNOSAVE) != 0) { KASSERT(ctx == NULL, ("non-null ctx after FPU_KERN_NOCTX")); KASSERT(PCPU_GET(fpcurthread) == NULL, ("non-NULL fpcurthread for PCB_FPUNOSAVE")); CRITICAL_ASSERT(td); clear_pcb_flags(pcb, PCB_FPUNOSAVE | PCB_FPUINITDONE); start_emulating(); } else { KASSERT((ctx->flags & FPU_KERN_CTX_INUSE) != 0, ("leaving not inuse ctx")); ctx->flags &= ~FPU_KERN_CTX_INUSE; if (is_fpu_kern_thread(0) && (ctx->flags & FPU_KERN_CTX_DUMMY) != 0) return (0); KASSERT((ctx->flags & FPU_KERN_CTX_DUMMY) == 0, ("dummy ctx")); critical_enter(); if (curthread == PCPU_GET(fpcurthread)) fpudrop(); pcb->pcb_save = ctx->prev; } if (pcb->pcb_save == get_pcb_user_save_pcb(pcb)) { if ((pcb->pcb_flags & PCB_USERFPUINITDONE) != 0) { set_pcb_flags(pcb, PCB_FPUINITDONE); if ((pcb->pcb_flags & PCB_KERNFPU_THR) == 0) clear_pcb_flags(pcb, PCB_KERNFPU); } else if ((pcb->pcb_flags & PCB_KERNFPU_THR) == 0) clear_pcb_flags(pcb, PCB_FPUINITDONE | PCB_KERNFPU); } else { if ((ctx->flags & FPU_KERN_CTX_FPUINITDONE) != 0) set_pcb_flags(pcb, PCB_FPUINITDONE); else clear_pcb_flags(pcb, PCB_FPUINITDONE); KASSERT(!PCB_USER_FPU(pcb), ("unpaired fpu_kern_leave")); } critical_exit(); return (0); } int fpu_kern_thread(u_int flags) { KASSERT((curthread->td_pflags & TDP_KTHREAD) != 0, ("Only kthread may use fpu_kern_thread")); KASSERT(curpcb->pcb_save == get_pcb_user_save_pcb(curpcb), ("mangled pcb_save")); KASSERT(PCB_USER_FPU(curpcb), ("recursive call")); set_pcb_flags(curpcb, PCB_KERNFPU | PCB_KERNFPU_THR); return (0); } int is_fpu_kern_thread(u_int flags) { if ((curthread->td_pflags & TDP_KTHREAD) == 0) return (0); return ((curpcb->pcb_flags & PCB_KERNFPU_THR) != 0); } /* * FPU save area alloc/free/init utility routines */ struct savefpu * fpu_save_area_alloc(void) { return (uma_zalloc(fpu_save_area_zone, M_WAITOK)); } void fpu_save_area_free(struct savefpu *fsa) { uma_zfree(fpu_save_area_zone, fsa); } void fpu_save_area_reset(struct savefpu *fsa) { bcopy(fpu_initialstate, fsa, cpu_max_ext_state_size); } diff --git a/sys/i386/i386/npx.c b/sys/i386/i386/npx.c index 34fd2e957169..4767d8896de9 100644 --- a/sys/i386/i386/npx.c +++ b/sys/i386/i386/npx.c @@ -1,1566 +1,1566 @@ /*- * Copyright (c) 1990 William Jolitz. * Copyright (c) 1991 The Regents of the University of California. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from: @(#)npx.c 7.2 (Berkeley) 5/12/91 */ #include __FBSDID("$FreeBSD$"); #include "opt_cpu.h" #include "opt_isa.h" #include "opt_npx.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef NPX_DEBUG #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DEV_ISA #include #endif /* * 387 and 287 Numeric Coprocessor Extension (NPX) Driver. */ #if defined(__GNUCLIKE_ASM) && !defined(lint) #define fldcw(cw) __asm __volatile("fldcw %0" : : "m" (cw)) #define fnclex() __asm __volatile("fnclex") #define fninit() __asm __volatile("fninit") #define fnsave(addr) __asm __volatile("fnsave %0" : "=m" (*(addr))) #define fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr))) #define fnstsw(addr) __asm __volatile("fnstsw %0" : "=am" (*(addr))) #define fp_divide_by_0() __asm __volatile( \ "fldz; fld1; fdiv %st,%st(1); fnop") #define frstor(addr) __asm __volatile("frstor %0" : : "m" (*(addr))) #define fxrstor(addr) __asm __volatile("fxrstor %0" : : "m" (*(addr))) #define fxsave(addr) __asm __volatile("fxsave %0" : "=m" (*(addr))) #define ldmxcsr(csr) __asm __volatile("ldmxcsr %0" : : "m" (csr)) #define stmxcsr(addr) __asm __volatile("stmxcsr %0" : : "m" (*(addr))) static __inline void xrstor(char *addr, uint64_t mask) { uint32_t low, hi; low = mask; hi = mask >> 32; __asm __volatile("xrstor %0" : : "m" (*addr), "a" (low), "d" (hi)); } static __inline void xsave(char *addr, uint64_t mask) { uint32_t low, hi; low = mask; hi = mask >> 32; __asm __volatile("xsave %0" : "=m" (*addr) : "a" (low), "d" (hi) : "memory"); } static __inline void xsaveopt(char *addr, uint64_t mask) { uint32_t low, hi; low = mask; hi = mask >> 32; __asm __volatile("xsaveopt %0" : "=m" (*addr) : "a" (low), "d" (hi) : "memory"); } #else /* !(__GNUCLIKE_ASM && !lint) */ void fldcw(u_short cw); void fnclex(void); void fninit(void); void fnsave(caddr_t addr); void fnstcw(caddr_t addr); void fnstsw(caddr_t addr); void fp_divide_by_0(void); void frstor(caddr_t addr); void fxsave(caddr_t addr); void fxrstor(caddr_t addr); void ldmxcsr(u_int csr); void stmxcsr(u_int *csr); void xrstor(char *addr, uint64_t mask); void xsave(char *addr, uint64_t mask); void xsaveopt(char *addr, uint64_t mask); #endif /* __GNUCLIKE_ASM && !lint */ #define start_emulating() load_cr0(rcr0() | CR0_TS) #define stop_emulating() clts() #define GET_FPU_CW(thread) \ (cpu_fxsr ? \ (thread)->td_pcb->pcb_save->sv_xmm.sv_env.en_cw : \ (thread)->td_pcb->pcb_save->sv_87.sv_env.en_cw) #define GET_FPU_SW(thread) \ (cpu_fxsr ? \ (thread)->td_pcb->pcb_save->sv_xmm.sv_env.en_sw : \ (thread)->td_pcb->pcb_save->sv_87.sv_env.en_sw) #define SET_FPU_CW(savefpu, value) do { \ if (cpu_fxsr) \ (savefpu)->sv_xmm.sv_env.en_cw = (value); \ else \ (savefpu)->sv_87.sv_env.en_cw = (value); \ } while (0) CTASSERT(sizeof(union savefpu) == 512); CTASSERT(sizeof(struct xstate_hdr) == 64); CTASSERT(sizeof(struct savefpu_ymm) == 832); /* * This requirement is to make it easier for asm code to calculate * offset of the fpu save area from the pcb address. FPU save area * must be 64-byte aligned. */ CTASSERT(sizeof(struct pcb) % XSAVE_AREA_ALIGN == 0); /* * Ensure the copy of XCR0 saved in a core is contained in the padding * area. */ CTASSERT(X86_XSTATE_XCR0_OFFSET >= offsetof(struct savexmm, sv_pad) && X86_XSTATE_XCR0_OFFSET + sizeof(uint64_t) <= sizeof(struct savexmm)); static void fpu_clean_state(void); static void fpurstor(union savefpu *); int hw_float; SYSCTL_INT(_hw, HW_FLOATINGPT, floatingpoint, CTLFLAG_RD, &hw_float, 0, "Floating point instructions executed in hardware"); int lazy_fpu_switch = 0; SYSCTL_INT(_hw, OID_AUTO, lazy_fpu_switch, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &lazy_fpu_switch, 0, "Lazily load FPU context after context switch"); int use_xsave; uint64_t xsave_mask; static uma_zone_t fpu_save_area_zone; static union savefpu *npx_initialstate; static struct xsave_area_elm_descr { u_int offset; u_int size; } *xsave_area_desc; static volatile u_int npx_traps_while_probing; alias_for_inthand_t probetrap; __asm(" \n\ .text \n\ .p2align 2,0x90 \n\ .type " __XSTRING(CNAME(probetrap)) ",@function \n\ " __XSTRING(CNAME(probetrap)) ": \n\ ss \n\ incl " __XSTRING(CNAME(npx_traps_while_probing)) " \n\ fnclex \n\ iret \n\ "); /* * Determine if an FPU is present and how to use it. */ static int npx_probe(void) { struct gate_descriptor save_idt_npxtrap; u_short control, status; /* * Modern CPUs all have an FPU that uses the INT16 interface * and provide a simple way to verify that, so handle the * common case right away. */ if (cpu_feature & CPUID_FPU) { hw_float = 1; return (1); } save_idt_npxtrap = idt[IDT_MF]; setidt(IDT_MF, probetrap, SDT_SYS386TGT, SEL_KPL, GSEL(GCODE_SEL, SEL_KPL)); /* * Don't trap while we're probing. */ stop_emulating(); /* * Finish resetting the coprocessor, if any. If there is an error * pending, then we may get a bogus IRQ13, but npx_intr() will handle * it OK. Bogus halts have never been observed, but we enabled * IRQ13 and cleared the BUSY# latch early to handle them anyway. */ fninit(); /* * Don't use fwait here because it might hang. * Don't use fnop here because it usually hangs if there is no FPU. */ DELAY(1000); /* wait for any IRQ13 */ #ifdef DIAGNOSTIC if (npx_traps_while_probing != 0) printf("fninit caused %u bogus npx trap(s)\n", npx_traps_while_probing); #endif /* * Check for a status of mostly zero. */ status = 0x5a5a; fnstsw(&status); if ((status & 0xb8ff) == 0) { /* * Good, now check for a proper control word. */ control = 0x5a5a; fnstcw(&control); if ((control & 0x1f3f) == 0x033f) { /* * We have an npx, now divide by 0 to see if exception * 16 works. */ control &= ~(1 << 2); /* enable divide by 0 trap */ fldcw(control); npx_traps_while_probing = 0; fp_divide_by_0(); if (npx_traps_while_probing != 0) { /* * Good, exception 16 works. */ hw_float = 1; goto cleanup; } printf( "FPU does not use exception 16 for error reporting\n"); goto cleanup; } } /* * Probe failed. Floating point simply won't work. * Notify user and disable FPU/MMX/SSE instruction execution. */ printf("WARNING: no FPU!\n"); __asm __volatile("smsw %%ax; orb %0,%%al; lmsw %%ax" : : "n" (CR0_EM | CR0_MP) : "ax"); cleanup: idt[IDT_MF] = save_idt_npxtrap; return (hw_float); } static void fpusave_xsaveopt(union savefpu *addr) { xsaveopt((char *)addr, xsave_mask); } static void fpusave_xsave(union savefpu *addr) { xsave((char *)addr, xsave_mask); } static void fpusave_fxsave(union savefpu *addr) { fxsave((char *)addr); } static void fpusave_fnsave(union savefpu *addr) { fnsave((char *)addr); } static void init_xsave(void) { if (use_xsave) return; if (!cpu_fxsr || (cpu_feature2 & CPUID2_XSAVE) == 0) return; use_xsave = 1; TUNABLE_INT_FETCH("hw.use_xsave", &use_xsave); } DEFINE_IFUNC(, void, fpusave, (union savefpu *)) { init_xsave(); if (use_xsave) return ((cpu_stdext_feature & CPUID_EXTSTATE_XSAVEOPT) != 0 ? fpusave_xsaveopt : fpusave_xsave); if (cpu_fxsr) return (fpusave_fxsave); return (fpusave_fnsave); } /* * Enable XSAVE if supported and allowed by user. * Calculate the xsave_mask. */ static void npxinit_bsp1(void) { u_int cp[4]; uint64_t xsave_mask_user; TUNABLE_INT_FETCH("hw.lazy_fpu_switch", &lazy_fpu_switch); if (!use_xsave) return; cpuid_count(0xd, 0x0, cp); xsave_mask = XFEATURE_ENABLED_X87 | XFEATURE_ENABLED_SSE; if ((cp[0] & xsave_mask) != xsave_mask) panic("CPU0 does not support X87 or SSE: %x", cp[0]); xsave_mask = ((uint64_t)cp[3] << 32) | cp[0]; xsave_mask_user = xsave_mask; TUNABLE_QUAD_FETCH("hw.xsave_mask", &xsave_mask_user); xsave_mask_user |= XFEATURE_ENABLED_X87 | XFEATURE_ENABLED_SSE; xsave_mask &= xsave_mask_user; if ((xsave_mask & XFEATURE_AVX512) != XFEATURE_AVX512) xsave_mask &= ~XFEATURE_AVX512; if ((xsave_mask & XFEATURE_MPX) != XFEATURE_MPX) xsave_mask &= ~XFEATURE_MPX; } /* * Calculate the fpu save area size. */ static void npxinit_bsp2(void) { u_int cp[4]; if (use_xsave) { cpuid_count(0xd, 0x0, cp); cpu_max_ext_state_size = cp[1]; /* * Reload the cpu_feature2, since we enabled OSXSAVE. */ do_cpuid(1, cp); cpu_feature2 = cp[2]; } else cpu_max_ext_state_size = sizeof(union savefpu); } /* * Initialize floating point unit. */ void npxinit(bool bsp) { static union savefpu dummy; register_t saveintr; u_int mxcsr; u_short control; if (bsp) { if (!npx_probe()) return; npxinit_bsp1(); } if (use_xsave) { load_cr4(rcr4() | CR4_XSAVE); load_xcr(XCR0, xsave_mask); } /* * XCR0 shall be set up before CPU can report the save area size. */ if (bsp) npxinit_bsp2(); /* * fninit has the same h/w bugs as fnsave. Use the detoxified * fnsave to throw away any junk in the fpu. fpusave() initializes * the fpu. * * It is too early for critical_enter() to work on AP. */ saveintr = intr_disable(); stop_emulating(); if (cpu_fxsr) fninit(); else fnsave(&dummy); control = __INITIAL_NPXCW__; fldcw(control); if (cpu_fxsr) { mxcsr = __INITIAL_MXCSR__; ldmxcsr(mxcsr); } start_emulating(); intr_restore(saveintr); } /* * On the boot CPU we generate a clean state that is used to * initialize the floating point unit when it is first used by a * process. */ static void npxinitstate(void *arg __unused) { uint64_t *xstate_bv; register_t saveintr; int cp[4], i, max_ext_n; if (!hw_float) return; /* Do potentially blocking operations before disabling interrupts. */ fpu_save_area_zone = uma_zcreate("FPU_save_area", cpu_max_ext_state_size, NULL, NULL, NULL, NULL, XSAVE_AREA_ALIGN - 1, 0); npx_initialstate = uma_zalloc(fpu_save_area_zone, M_WAITOK | M_ZERO); if (use_xsave) { if (xsave_mask >> 32 != 0) max_ext_n = fls(xsave_mask >> 32) + 32; else max_ext_n = fls(xsave_mask); xsave_area_desc = malloc(max_ext_n * sizeof(struct xsave_area_elm_descr), M_DEVBUF, M_WAITOK | M_ZERO); } saveintr = intr_disable(); stop_emulating(); if (cpu_fxsr) fpusave_fxsave(npx_initialstate); else fpusave_fnsave(npx_initialstate); if (cpu_fxsr) { if (npx_initialstate->sv_xmm.sv_env.en_mxcsr_mask) cpu_mxcsr_mask = npx_initialstate->sv_xmm.sv_env.en_mxcsr_mask; else cpu_mxcsr_mask = 0xFFBF; /* * The fninit instruction does not modify XMM * registers or x87 registers (MM/ST). The fpusave * call dumped the garbage contained in the registers * after reset to the initial state saved. Clear XMM * and x87 registers file image to make the startup * program state and signal handler XMM/x87 register * content predictable. */ bzero(npx_initialstate->sv_xmm.sv_fp, sizeof(npx_initialstate->sv_xmm.sv_fp)); bzero(npx_initialstate->sv_xmm.sv_xmm, sizeof(npx_initialstate->sv_xmm.sv_xmm)); } else bzero(npx_initialstate->sv_87.sv_ac, sizeof(npx_initialstate->sv_87.sv_ac)); /* * Create a table describing the layout of the CPU Extended * Save Area. */ if (use_xsave) { xstate_bv = (uint64_t *)((char *)(npx_initialstate + 1) + offsetof(struct xstate_hdr, xstate_bv)); *xstate_bv = XFEATURE_ENABLED_X87 | XFEATURE_ENABLED_SSE; /* x87 state */ xsave_area_desc[0].offset = 0; xsave_area_desc[0].size = 160; /* XMM */ xsave_area_desc[1].offset = 160; xsave_area_desc[1].size = 288 - 160; for (i = 2; i < max_ext_n; i++) { cpuid_count(0xd, i, cp); xsave_area_desc[i].offset = cp[1]; xsave_area_desc[i].size = cp[0]; } } start_emulating(); intr_restore(saveintr); } -SYSINIT(npxinitstate, SI_SUB_DRIVERS, SI_ORDER_ANY, npxinitstate, NULL); +SYSINIT(npxinitstate, SI_SUB_CPU, SI_ORDER_ANY, npxinitstate, NULL); /* * Free coprocessor (if we have it). */ void npxexit(struct thread *td) { critical_enter(); if (curthread == PCPU_GET(fpcurthread)) { stop_emulating(); fpusave(curpcb->pcb_save); start_emulating(); PCPU_SET(fpcurthread, NULL); } critical_exit(); #ifdef NPX_DEBUG if (hw_float) { u_int masked_exceptions; masked_exceptions = GET_FPU_CW(td) & GET_FPU_SW(td) & 0x7f; /* * Log exceptions that would have trapped with the old * control word (overflow, divide by 0, and invalid operand). */ if (masked_exceptions & 0x0d) log(LOG_ERR, "pid %d (%s) exited with masked floating point exceptions 0x%02x\n", td->td_proc->p_pid, td->td_proc->p_comm, masked_exceptions); } #endif } int npxformat(void) { if (!hw_float) return (_MC_FPFMT_NODEV); if (cpu_fxsr) return (_MC_FPFMT_XMM); return (_MC_FPFMT_387); } /* * The following mechanism is used to ensure that the FPE_... value * that is passed as a trapcode to the signal handler of the user * process does not have more than one bit set. * * Multiple bits may be set if the user process modifies the control * word while a status word bit is already set. While this is a sign * of bad coding, we have no choise than to narrow them down to one * bit, since we must not send a trapcode that is not exactly one of * the FPE_ macros. * * The mechanism has a static table with 127 entries. Each combination * of the 7 FPU status word exception bits directly translates to a * position in this table, where a single FPE_... value is stored. * This FPE_... value stored there is considered the "most important" * of the exception bits and will be sent as the signal code. The * precedence of the bits is based upon Intel Document "Numerical * Applications", Chapter "Special Computational Situations". * * The macro to choose one of these values does these steps: 1) Throw * away status word bits that cannot be masked. 2) Throw away the bits * currently masked in the control word, assuming the user isn't * interested in them anymore. 3) Reinsert status word bit 7 (stack * fault) if it is set, which cannot be masked but must be presered. * 4) Use the remaining bits to point into the trapcode table. * * The 6 maskable bits in order of their preference, as stated in the * above referenced Intel manual: * 1 Invalid operation (FP_X_INV) * 1a Stack underflow * 1b Stack overflow * 1c Operand of unsupported format * 1d SNaN operand. * 2 QNaN operand (not an exception, irrelavant here) * 3 Any other invalid-operation not mentioned above or zero divide * (FP_X_INV, FP_X_DZ) * 4 Denormal operand (FP_X_DNML) * 5 Numeric over/underflow (FP_X_OFL, FP_X_UFL) * 6 Inexact result (FP_X_IMP) */ static char fpetable[128] = { 0, FPE_FLTINV, /* 1 - INV */ FPE_FLTUND, /* 2 - DNML */ FPE_FLTINV, /* 3 - INV | DNML */ FPE_FLTDIV, /* 4 - DZ */ FPE_FLTINV, /* 5 - INV | DZ */ FPE_FLTDIV, /* 6 - DNML | DZ */ FPE_FLTINV, /* 7 - INV | DNML | DZ */ FPE_FLTOVF, /* 8 - OFL */ FPE_FLTINV, /* 9 - INV | OFL */ FPE_FLTUND, /* A - DNML | OFL */ FPE_FLTINV, /* B - INV | DNML | OFL */ FPE_FLTDIV, /* C - DZ | OFL */ FPE_FLTINV, /* D - INV | DZ | OFL */ FPE_FLTDIV, /* E - DNML | DZ | OFL */ FPE_FLTINV, /* F - INV | DNML | DZ | OFL */ FPE_FLTUND, /* 10 - UFL */ FPE_FLTINV, /* 11 - INV | UFL */ FPE_FLTUND, /* 12 - DNML | UFL */ FPE_FLTINV, /* 13 - INV | DNML | UFL */ FPE_FLTDIV, /* 14 - DZ | UFL */ FPE_FLTINV, /* 15 - INV | DZ | UFL */ FPE_FLTDIV, /* 16 - DNML | DZ | UFL */ FPE_FLTINV, /* 17 - INV | DNML | DZ | UFL */ FPE_FLTOVF, /* 18 - OFL | UFL */ FPE_FLTINV, /* 19 - INV | OFL | UFL */ FPE_FLTUND, /* 1A - DNML | OFL | UFL */ FPE_FLTINV, /* 1B - INV | DNML | OFL | UFL */ FPE_FLTDIV, /* 1C - DZ | OFL | UFL */ FPE_FLTINV, /* 1D - INV | DZ | OFL | UFL */ FPE_FLTDIV, /* 1E - DNML | DZ | OFL | UFL */ FPE_FLTINV, /* 1F - INV | DNML | DZ | OFL | UFL */ FPE_FLTRES, /* 20 - IMP */ FPE_FLTINV, /* 21 - INV | IMP */ FPE_FLTUND, /* 22 - DNML | IMP */ FPE_FLTINV, /* 23 - INV | DNML | IMP */ FPE_FLTDIV, /* 24 - DZ | IMP */ FPE_FLTINV, /* 25 - INV | DZ | IMP */ FPE_FLTDIV, /* 26 - DNML | DZ | IMP */ FPE_FLTINV, /* 27 - INV | DNML | DZ | IMP */ FPE_FLTOVF, /* 28 - OFL | IMP */ FPE_FLTINV, /* 29 - INV | OFL | IMP */ FPE_FLTUND, /* 2A - DNML | OFL | IMP */ FPE_FLTINV, /* 2B - INV | DNML | OFL | IMP */ FPE_FLTDIV, /* 2C - DZ | OFL | IMP */ FPE_FLTINV, /* 2D - INV | DZ | OFL | IMP */ FPE_FLTDIV, /* 2E - DNML | DZ | OFL | IMP */ FPE_FLTINV, /* 2F - INV | DNML | DZ | OFL | IMP */ FPE_FLTUND, /* 30 - UFL | IMP */ FPE_FLTINV, /* 31 - INV | UFL | IMP */ FPE_FLTUND, /* 32 - DNML | UFL | IMP */ FPE_FLTINV, /* 33 - INV | DNML | UFL | IMP */ FPE_FLTDIV, /* 34 - DZ | UFL | IMP */ FPE_FLTINV, /* 35 - INV | DZ | UFL | IMP */ FPE_FLTDIV, /* 36 - DNML | DZ | UFL | IMP */ FPE_FLTINV, /* 37 - INV | DNML | DZ | UFL | IMP */ FPE_FLTOVF, /* 38 - OFL | UFL | IMP */ FPE_FLTINV, /* 39 - INV | OFL | UFL | IMP */ FPE_FLTUND, /* 3A - DNML | OFL | UFL | IMP */ FPE_FLTINV, /* 3B - INV | DNML | OFL | UFL | IMP */ FPE_FLTDIV, /* 3C - DZ | OFL | UFL | IMP */ FPE_FLTINV, /* 3D - INV | DZ | OFL | UFL | IMP */ FPE_FLTDIV, /* 3E - DNML | DZ | OFL | UFL | IMP */ FPE_FLTINV, /* 3F - INV | DNML | DZ | OFL | UFL | IMP */ FPE_FLTSUB, /* 40 - STK */ FPE_FLTSUB, /* 41 - INV | STK */ FPE_FLTUND, /* 42 - DNML | STK */ FPE_FLTSUB, /* 43 - INV | DNML | STK */ FPE_FLTDIV, /* 44 - DZ | STK */ FPE_FLTSUB, /* 45 - INV | DZ | STK */ FPE_FLTDIV, /* 46 - DNML | DZ | STK */ FPE_FLTSUB, /* 47 - INV | DNML | DZ | STK */ FPE_FLTOVF, /* 48 - OFL | STK */ FPE_FLTSUB, /* 49 - INV | OFL | STK */ FPE_FLTUND, /* 4A - DNML | OFL | STK */ FPE_FLTSUB, /* 4B - INV | DNML | OFL | STK */ FPE_FLTDIV, /* 4C - DZ | OFL | STK */ FPE_FLTSUB, /* 4D - INV | DZ | OFL | STK */ FPE_FLTDIV, /* 4E - DNML | DZ | OFL | STK */ FPE_FLTSUB, /* 4F - INV | DNML | DZ | OFL | STK */ FPE_FLTUND, /* 50 - UFL | STK */ FPE_FLTSUB, /* 51 - INV | UFL | STK */ FPE_FLTUND, /* 52 - DNML | UFL | STK */ FPE_FLTSUB, /* 53 - INV | DNML | UFL | STK */ FPE_FLTDIV, /* 54 - DZ | UFL | STK */ FPE_FLTSUB, /* 55 - INV | DZ | UFL | STK */ FPE_FLTDIV, /* 56 - DNML | DZ | UFL | STK */ FPE_FLTSUB, /* 57 - INV | DNML | DZ | UFL | STK */ FPE_FLTOVF, /* 58 - OFL | UFL | STK */ FPE_FLTSUB, /* 59 - INV | OFL | UFL | STK */ FPE_FLTUND, /* 5A - DNML | OFL | UFL | STK */ FPE_FLTSUB, /* 5B - INV | DNML | OFL | UFL | STK */ FPE_FLTDIV, /* 5C - DZ | OFL | UFL | STK */ FPE_FLTSUB, /* 5D - INV | DZ | OFL | UFL | STK */ FPE_FLTDIV, /* 5E - DNML | DZ | OFL | UFL | STK */ FPE_FLTSUB, /* 5F - INV | DNML | DZ | OFL | UFL | STK */ FPE_FLTRES, /* 60 - IMP | STK */ FPE_FLTSUB, /* 61 - INV | IMP | STK */ FPE_FLTUND, /* 62 - DNML | IMP | STK */ FPE_FLTSUB, /* 63 - INV | DNML | IMP | STK */ FPE_FLTDIV, /* 64 - DZ | IMP | STK */ FPE_FLTSUB, /* 65 - INV | DZ | IMP | STK */ FPE_FLTDIV, /* 66 - DNML | DZ | IMP | STK */ FPE_FLTSUB, /* 67 - INV | DNML | DZ | IMP | STK */ FPE_FLTOVF, /* 68 - OFL | IMP | STK */ FPE_FLTSUB, /* 69 - INV | OFL | IMP | STK */ FPE_FLTUND, /* 6A - DNML | OFL | IMP | STK */ FPE_FLTSUB, /* 6B - INV | DNML | OFL | IMP | STK */ FPE_FLTDIV, /* 6C - DZ | OFL | IMP | STK */ FPE_FLTSUB, /* 6D - INV | DZ | OFL | IMP | STK */ FPE_FLTDIV, /* 6E - DNML | DZ | OFL | IMP | STK */ FPE_FLTSUB, /* 6F - INV | DNML | DZ | OFL | IMP | STK */ FPE_FLTUND, /* 70 - UFL | IMP | STK */ FPE_FLTSUB, /* 71 - INV | UFL | IMP | STK */ FPE_FLTUND, /* 72 - DNML | UFL | IMP | STK */ FPE_FLTSUB, /* 73 - INV | DNML | UFL | IMP | STK */ FPE_FLTDIV, /* 74 - DZ | UFL | IMP | STK */ FPE_FLTSUB, /* 75 - INV | DZ | UFL | IMP | STK */ FPE_FLTDIV, /* 76 - DNML | DZ | UFL | IMP | STK */ FPE_FLTSUB, /* 77 - INV | DNML | DZ | UFL | IMP | STK */ FPE_FLTOVF, /* 78 - OFL | UFL | IMP | STK */ FPE_FLTSUB, /* 79 - INV | OFL | UFL | IMP | STK */ FPE_FLTUND, /* 7A - DNML | OFL | UFL | IMP | STK */ FPE_FLTSUB, /* 7B - INV | DNML | OFL | UFL | IMP | STK */ FPE_FLTDIV, /* 7C - DZ | OFL | UFL | IMP | STK */ FPE_FLTSUB, /* 7D - INV | DZ | OFL | UFL | IMP | STK */ FPE_FLTDIV, /* 7E - DNML | DZ | OFL | UFL | IMP | STK */ FPE_FLTSUB, /* 7F - INV | DNML | DZ | OFL | UFL | IMP | STK */ }; /* * Read the FP status and control words, then generate si_code value * for SIGFPE. The error code chosen will be one of the * FPE_... macros. It will be sent as the second argument to old * BSD-style signal handlers and as "siginfo_t->si_code" (second * argument) to SA_SIGINFO signal handlers. * * Some time ago, we cleared the x87 exceptions with FNCLEX there. * Clearing exceptions was necessary mainly to avoid IRQ13 bugs. The * usermode code which understands the FPU hardware enough to enable * the exceptions, can also handle clearing the exception state in the * handler. The only consequence of not clearing the exception is the * rethrow of the SIGFPE on return from the signal handler and * reexecution of the corresponding instruction. * * For XMM traps, the exceptions were never cleared. */ int npxtrap_x87(void) { u_short control, status; if (!hw_float) { printf( "npxtrap_x87: fpcurthread = %p, curthread = %p, hw_float = %d\n", PCPU_GET(fpcurthread), curthread, hw_float); panic("npxtrap from nowhere"); } critical_enter(); /* * Interrupt handling (for another interrupt) may have pushed the * state to memory. Fetch the relevant parts of the state from * wherever they are. */ if (PCPU_GET(fpcurthread) != curthread) { control = GET_FPU_CW(curthread); status = GET_FPU_SW(curthread); } else { fnstcw(&control); fnstsw(&status); } critical_exit(); return (fpetable[status & ((~control & 0x3f) | 0x40)]); } int npxtrap_sse(void) { u_int mxcsr; if (!hw_float) { printf( "npxtrap_sse: fpcurthread = %p, curthread = %p, hw_float = %d\n", PCPU_GET(fpcurthread), curthread, hw_float); panic("npxtrap from nowhere"); } critical_enter(); if (PCPU_GET(fpcurthread) != curthread) mxcsr = curthread->td_pcb->pcb_save->sv_xmm.sv_env.en_mxcsr; else stmxcsr(&mxcsr); critical_exit(); return (fpetable[(mxcsr & (~mxcsr >> 7)) & 0x3f]); } static void restore_npx_curthread(struct thread *td, struct pcb *pcb) { /* * Record new context early in case frstor causes a trap. */ PCPU_SET(fpcurthread, td); stop_emulating(); if (cpu_fxsr) fpu_clean_state(); if ((pcb->pcb_flags & PCB_NPXINITDONE) == 0) { /* * This is the first time this thread has used the FPU or * the PCB doesn't contain a clean FPU state. Explicitly * load an initial state. * * We prefer to restore the state from the actual save * area in PCB instead of directly loading from * npx_initialstate, to ignite the XSAVEOPT * tracking engine. */ bcopy(npx_initialstate, pcb->pcb_save, cpu_max_ext_state_size); fpurstor(pcb->pcb_save); if (pcb->pcb_initial_npxcw != __INITIAL_NPXCW__) fldcw(pcb->pcb_initial_npxcw); pcb->pcb_flags |= PCB_NPXINITDONE; if (PCB_USER_FPU(pcb)) pcb->pcb_flags |= PCB_NPXUSERINITDONE; } else { fpurstor(pcb->pcb_save); } } /* * Implement device not available (DNA) exception * * It would be better to switch FP context here (if curthread != fpcurthread) * and not necessarily for every context switch, but it is too hard to * access foreign pcb's. */ int npxdna(void) { struct thread *td; if (!hw_float) return (0); td = curthread; critical_enter(); KASSERT((curpcb->pcb_flags & PCB_NPXNOSAVE) == 0, ("npxdna while in fpu_kern_enter(FPU_KERN_NOCTX)")); if (__predict_false(PCPU_GET(fpcurthread) == td)) { /* * Some virtual machines seems to set %cr0.TS at * arbitrary moments. Silently clear the TS bit * regardless of the eager/lazy FPU context switch * mode. */ stop_emulating(); } else { if (__predict_false(PCPU_GET(fpcurthread) != NULL)) { printf( "npxdna: fpcurthread = %p (%d), curthread = %p (%d)\n", PCPU_GET(fpcurthread), PCPU_GET(fpcurthread)->td_proc->p_pid, td, td->td_proc->p_pid); panic("npxdna"); } restore_npx_curthread(td, td->td_pcb); } critical_exit(); return (1); } /* * Wrapper for fpusave() called from context switch routines. * * npxsave() must be called with interrupts disabled, so that it clears * fpcurthread atomically with saving the state. We require callers to do the * disabling, since most callers need to disable interrupts anyway to call * npxsave() atomically with checking fpcurthread. */ void npxsave(union savefpu *addr) { stop_emulating(); fpusave(addr); } void npxswitch(struct thread *td, struct pcb *pcb); void npxswitch(struct thread *td, struct pcb *pcb) { if (lazy_fpu_switch || (td->td_pflags & TDP_KTHREAD) != 0 || !PCB_USER_FPU(pcb)) { start_emulating(); PCPU_SET(fpcurthread, NULL); } else if (PCPU_GET(fpcurthread) != td) { restore_npx_curthread(td, pcb); } } /* * Unconditionally save the current co-processor state across suspend and * resume. */ void npxsuspend(union savefpu *addr) { register_t cr0; if (!hw_float) return; if (PCPU_GET(fpcurthread) == NULL) { bcopy(npx_initialstate, addr, cpu_max_ext_state_size); return; } cr0 = rcr0(); stop_emulating(); fpusave(addr); load_cr0(cr0); } void npxresume(union savefpu *addr) { register_t cr0; if (!hw_float) return; cr0 = rcr0(); npxinit(false); stop_emulating(); fpurstor(addr); load_cr0(cr0); } void npxdrop(void) { struct thread *td; /* * Discard pending exceptions in the !cpu_fxsr case so that unmasked * ones don't cause a panic on the next frstor. */ if (!cpu_fxsr) fnclex(); td = PCPU_GET(fpcurthread); KASSERT(td == curthread, ("fpudrop: fpcurthread != curthread")); CRITICAL_ASSERT(td); PCPU_SET(fpcurthread, NULL); td->td_pcb->pcb_flags &= ~PCB_NPXINITDONE; start_emulating(); } /* * Get the user state of the FPU into pcb->pcb_user_save without * dropping ownership (if possible). It returns the FPU ownership * status. */ int npxgetregs(struct thread *td) { struct pcb *pcb; uint64_t *xstate_bv, bit; char *sa; int max_ext_n, i; int owned; if (!hw_float) return (_MC_FPOWNED_NONE); pcb = td->td_pcb; critical_enter(); if ((pcb->pcb_flags & PCB_NPXINITDONE) == 0) { bcopy(npx_initialstate, get_pcb_user_save_pcb(pcb), cpu_max_ext_state_size); SET_FPU_CW(get_pcb_user_save_pcb(pcb), pcb->pcb_initial_npxcw); npxuserinited(td); critical_exit(); return (_MC_FPOWNED_PCB); } if (td == PCPU_GET(fpcurthread)) { fpusave(get_pcb_user_save_pcb(pcb)); if (!cpu_fxsr) /* * fnsave initializes the FPU and destroys whatever * context it contains. Make sure the FPU owner * starts with a clean state next time. */ npxdrop(); owned = _MC_FPOWNED_FPU; } else { owned = _MC_FPOWNED_PCB; } if (use_xsave) { /* * Handle partially saved state. */ sa = (char *)get_pcb_user_save_pcb(pcb); xstate_bv = (uint64_t *)(sa + sizeof(union savefpu) + offsetof(struct xstate_hdr, xstate_bv)); if (xsave_mask >> 32 != 0) max_ext_n = fls(xsave_mask >> 32) + 32; else max_ext_n = fls(xsave_mask); for (i = 0; i < max_ext_n; i++) { bit = 1ULL << i; if ((xsave_mask & bit) == 0 || (*xstate_bv & bit) != 0) continue; bcopy((char *)npx_initialstate + xsave_area_desc[i].offset, sa + xsave_area_desc[i].offset, xsave_area_desc[i].size); *xstate_bv |= bit; } } critical_exit(); return (owned); } void npxuserinited(struct thread *td) { struct pcb *pcb; CRITICAL_ASSERT(td); pcb = td->td_pcb; if (PCB_USER_FPU(pcb)) pcb->pcb_flags |= PCB_NPXINITDONE; pcb->pcb_flags |= PCB_NPXUSERINITDONE; } int npxsetxstate(struct thread *td, char *xfpustate, size_t xfpustate_size) { struct xstate_hdr *hdr, *ehdr; size_t len, max_len; uint64_t bv; /* XXXKIB should we clear all extended state in xstate_bv instead ? */ if (xfpustate == NULL) return (0); if (!use_xsave) return (EOPNOTSUPP); len = xfpustate_size; if (len < sizeof(struct xstate_hdr)) return (EINVAL); max_len = cpu_max_ext_state_size - sizeof(union savefpu); if (len > max_len) return (EINVAL); ehdr = (struct xstate_hdr *)xfpustate; bv = ehdr->xstate_bv; /* * Avoid #gp. */ if (bv & ~xsave_mask) return (EINVAL); hdr = (struct xstate_hdr *)(get_pcb_user_save_td(td) + 1); hdr->xstate_bv = bv; bcopy(xfpustate + sizeof(struct xstate_hdr), (char *)(hdr + 1), len - sizeof(struct xstate_hdr)); return (0); } int npxsetregs(struct thread *td, union savefpu *addr, char *xfpustate, size_t xfpustate_size) { struct pcb *pcb; int error; if (!hw_float) return (ENXIO); if (cpu_fxsr) addr->sv_xmm.sv_env.en_mxcsr &= cpu_mxcsr_mask; pcb = td->td_pcb; error = 0; critical_enter(); if (td == PCPU_GET(fpcurthread) && PCB_USER_FPU(pcb)) { error = npxsetxstate(td, xfpustate, xfpustate_size); if (error == 0) { if (!cpu_fxsr) fnclex(); /* As in npxdrop(). */ bcopy(addr, get_pcb_user_save_td(td), sizeof(*addr)); fpurstor(get_pcb_user_save_td(td)); pcb->pcb_flags |= PCB_NPXUSERINITDONE | PCB_NPXINITDONE; } } else { error = npxsetxstate(td, xfpustate, xfpustate_size); if (error == 0) { bcopy(addr, get_pcb_user_save_td(td), sizeof(*addr)); npxuserinited(td); } } critical_exit(); return (error); } static void npx_fill_fpregs_xmm1(struct savexmm *sv_xmm, struct save87 *sv_87) { struct env87 *penv_87; struct envxmm *penv_xmm; struct fpacc87 *fx_reg; int i, st; uint64_t mantissa; uint16_t tw, exp; uint8_t ab_tw; penv_87 = &sv_87->sv_env; penv_xmm = &sv_xmm->sv_env; /* FPU control/status */ penv_87->en_cw = penv_xmm->en_cw; penv_87->en_sw = penv_xmm->en_sw; penv_87->en_fip = penv_xmm->en_fip; penv_87->en_fcs = penv_xmm->en_fcs; penv_87->en_opcode = penv_xmm->en_opcode; penv_87->en_foo = penv_xmm->en_foo; penv_87->en_fos = penv_xmm->en_fos; /* * FPU registers and tags. * For ST(i), i = fpu_reg - top; we start with fpu_reg=7. */ st = 7 - ((penv_xmm->en_sw >> 11) & 7); ab_tw = penv_xmm->en_tw; tw = 0; for (i = 0x80; i != 0; i >>= 1) { sv_87->sv_ac[st] = sv_xmm->sv_fp[st].fp_acc; tw <<= 2; if (ab_tw & i) { /* Non-empty - we need to check ST(i) */ fx_reg = &sv_xmm->sv_fp[st].fp_acc; /* The first 64 bits contain the mantissa. */ mantissa = *((uint64_t *)fx_reg->fp_bytes); /* * The final 16 bits contain the sign bit and the exponent. * Mask the sign bit since it is of no consequence to these * tests. */ exp = *((uint16_t *)&fx_reg->fp_bytes[8]) & 0x7fff; if (exp == 0) { if (mantissa == 0) tw |= 1; /* Zero */ else tw |= 2; /* Denormal */ } else if (exp == 0x7fff) tw |= 2; /* Infinity or NaN */ } else tw |= 3; /* Empty */ st = (st - 1) & 7; } penv_87->en_tw = tw; } void npx_fill_fpregs_xmm(struct savexmm *sv_xmm, struct save87 *sv_87) { bzero(sv_87, sizeof(*sv_87)); npx_fill_fpregs_xmm1(sv_xmm, sv_87); } void npx_set_fpregs_xmm(struct save87 *sv_87, struct savexmm *sv_xmm) { struct env87 *penv_87; struct envxmm *penv_xmm; int i; penv_87 = &sv_87->sv_env; penv_xmm = &sv_xmm->sv_env; /* FPU control/status */ penv_xmm->en_cw = penv_87->en_cw; penv_xmm->en_sw = penv_87->en_sw; penv_xmm->en_fip = penv_87->en_fip; penv_xmm->en_fcs = penv_87->en_fcs; penv_xmm->en_opcode = penv_87->en_opcode; penv_xmm->en_foo = penv_87->en_foo; penv_xmm->en_fos = penv_87->en_fos; /* * FPU registers and tags. * Abridged / Full translation (values in binary), see FXSAVE spec. * 0 11 * 1 00, 01, 10 */ penv_xmm->en_tw = 0; for (i = 0; i < 8; ++i) { sv_xmm->sv_fp[i].fp_acc = sv_87->sv_ac[i]; if ((penv_87->en_tw & (3 << i * 2)) != (3 << i * 2)) penv_xmm->en_tw |= 1 << i; } } void npx_get_fsave(void *addr) { struct thread *td; union savefpu *sv; td = curthread; npxgetregs(td); sv = get_pcb_user_save_td(td); if (cpu_fxsr) npx_fill_fpregs_xmm1(&sv->sv_xmm, addr); else bcopy(sv, addr, sizeof(struct env87) + sizeof(struct fpacc87[8])); } int npx_set_fsave(void *addr) { union savefpu sv; int error; bzero(&sv, sizeof(sv)); if (cpu_fxsr) npx_set_fpregs_xmm(addr, &sv.sv_xmm); else bcopy(addr, &sv, sizeof(struct env87) + sizeof(struct fpacc87[8])); error = npxsetregs(curthread, &sv, NULL, 0); return (error); } /* * On AuthenticAMD processors, the fxrstor instruction does not restore * the x87's stored last instruction pointer, last data pointer, and last * opcode values, except in the rare case in which the exception summary * (ES) bit in the x87 status word is set to 1. * * In order to avoid leaking this information across processes, we clean * these values by performing a dummy load before executing fxrstor(). */ static void fpu_clean_state(void) { static float dummy_variable = 0.0; u_short status; /* * Clear the ES bit in the x87 status word if it is currently * set, in order to avoid causing a fault in the upcoming load. */ fnstsw(&status); if (status & 0x80) fnclex(); /* * Load the dummy variable into the x87 stack. This mangles * the x87 stack, but we don't care since we're about to call * fxrstor() anyway. */ __asm __volatile("ffree %%st(7); flds %0" : : "m" (dummy_variable)); } static void fpurstor(union savefpu *addr) { if (use_xsave) xrstor((char *)addr, xsave_mask); else if (cpu_fxsr) fxrstor(addr); else frstor(addr); } #ifdef DEV_ISA /* * This sucks up the legacy ISA support assignments from PNPBIOS/ACPI. */ static struct isa_pnp_id npxisa_ids[] = { { 0x040cd041, "Legacy ISA coprocessor support" }, /* PNP0C04 */ { 0 } }; static int npxisa_probe(device_t dev) { int result; if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, npxisa_ids)) <= 0) { device_quiet(dev); } return(result); } static int npxisa_attach(device_t dev) { return (0); } static device_method_t npxisa_methods[] = { /* Device interface */ DEVMETHOD(device_probe, npxisa_probe), DEVMETHOD(device_attach, npxisa_attach), DEVMETHOD(device_detach, bus_generic_detach), DEVMETHOD(device_shutdown, bus_generic_shutdown), DEVMETHOD(device_suspend, bus_generic_suspend), DEVMETHOD(device_resume, bus_generic_resume), { 0, 0 } }; static driver_t npxisa_driver = { "npxisa", npxisa_methods, 1, /* no softc */ }; static devclass_t npxisa_devclass; DRIVER_MODULE(npxisa, isa, npxisa_driver, npxisa_devclass, 0, 0); DRIVER_MODULE(npxisa, acpi, npxisa_driver, npxisa_devclass, 0, 0); ISA_PNP_INFO(npxisa_ids); #endif /* DEV_ISA */ static MALLOC_DEFINE(M_FPUKERN_CTX, "fpukern_ctx", "Kernel contexts for FPU state"); #define FPU_KERN_CTX_NPXINITDONE 0x01 #define FPU_KERN_CTX_DUMMY 0x02 #define FPU_KERN_CTX_INUSE 0x04 struct fpu_kern_ctx { union savefpu *prev; uint32_t flags; char hwstate1[]; }; struct fpu_kern_ctx * fpu_kern_alloc_ctx(u_int flags) { struct fpu_kern_ctx *res; size_t sz; sz = sizeof(struct fpu_kern_ctx) + XSAVE_AREA_ALIGN + cpu_max_ext_state_size; res = malloc(sz, M_FPUKERN_CTX, ((flags & FPU_KERN_NOWAIT) ? M_NOWAIT : M_WAITOK) | M_ZERO); return (res); } void fpu_kern_free_ctx(struct fpu_kern_ctx *ctx) { KASSERT((ctx->flags & FPU_KERN_CTX_INUSE) == 0, ("free'ing inuse ctx")); /* XXXKIB clear the memory ? */ free(ctx, M_FPUKERN_CTX); } static union savefpu * fpu_kern_ctx_savefpu(struct fpu_kern_ctx *ctx) { vm_offset_t p; p = (vm_offset_t)&ctx->hwstate1; p = roundup2(p, XSAVE_AREA_ALIGN); return ((union savefpu *)p); } void fpu_kern_enter(struct thread *td, struct fpu_kern_ctx *ctx, u_int flags) { struct pcb *pcb; pcb = td->td_pcb; KASSERT((flags & FPU_KERN_NOCTX) != 0 || ctx != NULL, ("ctx is required when !FPU_KERN_NOCTX")); KASSERT(ctx == NULL || (ctx->flags & FPU_KERN_CTX_INUSE) == 0, ("using inuse ctx")); KASSERT((pcb->pcb_flags & PCB_NPXNOSAVE) == 0, ("recursive fpu_kern_enter while in PCB_NPXNOSAVE state")); if ((flags & FPU_KERN_NOCTX) != 0) { critical_enter(); stop_emulating(); if (curthread == PCPU_GET(fpcurthread)) { fpusave(curpcb->pcb_save); PCPU_SET(fpcurthread, NULL); } else { KASSERT(PCPU_GET(fpcurthread) == NULL, ("invalid fpcurthread")); } /* * This breaks XSAVEOPT tracker, but * PCB_NPXNOSAVE state is supposed to never need to * save FPU context at all. */ fpurstor(npx_initialstate); pcb->pcb_flags |= PCB_KERNNPX | PCB_NPXNOSAVE | PCB_NPXINITDONE; return; } if ((flags & FPU_KERN_KTHR) != 0 && is_fpu_kern_thread(0)) { ctx->flags = FPU_KERN_CTX_DUMMY | FPU_KERN_CTX_INUSE; return; } pcb = td->td_pcb; critical_enter(); KASSERT(!PCB_USER_FPU(pcb) || pcb->pcb_save == get_pcb_user_save_pcb(pcb), ("mangled pcb_save")); ctx->flags = FPU_KERN_CTX_INUSE; if ((pcb->pcb_flags & PCB_NPXINITDONE) != 0) ctx->flags |= FPU_KERN_CTX_NPXINITDONE; npxexit(td); ctx->prev = pcb->pcb_save; pcb->pcb_save = fpu_kern_ctx_savefpu(ctx); pcb->pcb_flags |= PCB_KERNNPX; pcb->pcb_flags &= ~PCB_NPXINITDONE; critical_exit(); } int fpu_kern_leave(struct thread *td, struct fpu_kern_ctx *ctx) { struct pcb *pcb; pcb = td->td_pcb; if ((pcb->pcb_flags & PCB_NPXNOSAVE) != 0) { KASSERT(ctx == NULL, ("non-null ctx after FPU_KERN_NOCTX")); KASSERT(PCPU_GET(fpcurthread) == NULL, ("non-NULL fpcurthread for PCB_NPXNOSAVE")); CRITICAL_ASSERT(td); pcb->pcb_flags &= ~(PCB_NPXNOSAVE | PCB_NPXINITDONE); start_emulating(); } else { KASSERT((ctx->flags & FPU_KERN_CTX_INUSE) != 0, ("leaving not inuse ctx")); ctx->flags &= ~FPU_KERN_CTX_INUSE; if (is_fpu_kern_thread(0) && (ctx->flags & FPU_KERN_CTX_DUMMY) != 0) return (0); KASSERT((ctx->flags & FPU_KERN_CTX_DUMMY) == 0, ("dummy ctx")); critical_enter(); if (curthread == PCPU_GET(fpcurthread)) npxdrop(); pcb->pcb_save = ctx->prev; } if (pcb->pcb_save == get_pcb_user_save_pcb(pcb)) { if ((pcb->pcb_flags & PCB_NPXUSERINITDONE) != 0) { pcb->pcb_flags |= PCB_NPXINITDONE; if ((pcb->pcb_flags & PCB_KERNNPX_THR) == 0) pcb->pcb_flags &= ~PCB_KERNNPX; } else if ((pcb->pcb_flags & PCB_KERNNPX_THR) == 0) pcb->pcb_flags &= ~(PCB_NPXINITDONE | PCB_KERNNPX); } else { if ((ctx->flags & FPU_KERN_CTX_NPXINITDONE) != 0) pcb->pcb_flags |= PCB_NPXINITDONE; else pcb->pcb_flags &= ~PCB_NPXINITDONE; KASSERT(!PCB_USER_FPU(pcb), ("unpaired fpu_kern_leave")); } critical_exit(); return (0); } int fpu_kern_thread(u_int flags) { KASSERT((curthread->td_pflags & TDP_KTHREAD) != 0, ("Only kthread may use fpu_kern_thread")); KASSERT(curpcb->pcb_save == get_pcb_user_save_pcb(curpcb), ("mangled pcb_save")); KASSERT(PCB_USER_FPU(curpcb), ("recursive call")); curpcb->pcb_flags |= PCB_KERNNPX | PCB_KERNNPX_THR; return (0); } int is_fpu_kern_thread(u_int flags) { if ((curthread->td_pflags & TDP_KTHREAD) == 0) return (0); return ((curpcb->pcb_flags & PCB_KERNNPX_THR) != 0); } /* * FPU save area alloc/free/init utility routines */ union savefpu * fpu_save_area_alloc(void) { return (uma_zalloc(fpu_save_area_zone, M_WAITOK)); } void fpu_save_area_free(union savefpu *fsa) { uma_zfree(fpu_save_area_zone, fsa); } void fpu_save_area_reset(union savefpu *fsa) { bcopy(npx_initialstate, fsa, cpu_max_ext_state_size); }