Index: head/sys/amd64/amd64/cpu_switch.S =================================================================== --- head/sys/amd64/amd64/cpu_switch.S (revision 335071) +++ head/sys/amd64/amd64/cpu_switch.S (revision 335072) @@ -1,504 +1,501 @@ /*- * Copyright (c) 2003 Peter Wemm. * Copyright (c) 1990 The Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * William Jolitz. * * 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. * * $FreeBSD$ */ #include #include #include "assym.inc" #include "opt_sched.h" /*****************************************************************************/ /* Scheduling */ /*****************************************************************************/ .text #ifdef SMP #define LK lock ; #else #define LK #endif #if defined(SCHED_ULE) && defined(SMP) #define SETLK xchgq #else #define SETLK movq #endif /* * cpu_throw() * * This is the second half of cpu_switch(). It is used when the current * thread is either a dummy or slated to die, and we no longer care * about its state. This is only a slight optimization and is probably * not worth it anymore. Note that we need to clear the pm_active bits so * we do need the old proc if it still exists. * %rdi = oldtd * %rsi = newtd */ ENTRY(cpu_throw) movq %rsi,%r12 movq %rsi,%rdi call pmap_activate_sw jmp sw1 END(cpu_throw) /* * cpu_switch(old, new, mtx) * * Save the current thread state, then select the next thread to run * and load its state. * %rdi = oldtd * %rsi = newtd * %rdx = mtx */ ENTRY(cpu_switch) /* Switch to new thread. First, save context. */ movq TD_PCB(%rdi),%r8 movq (%rsp),%rax /* Hardware registers */ movq %r15,PCB_R15(%r8) movq %r14,PCB_R14(%r8) movq %r13,PCB_R13(%r8) movq %r12,PCB_R12(%r8) movq %rbp,PCB_RBP(%r8) movq %rsp,PCB_RSP(%r8) movq %rbx,PCB_RBX(%r8) movq %rax,PCB_RIP(%r8) testl $PCB_FULL_IRET,PCB_FLAGS(%r8) jnz 2f orl $PCB_FULL_IRET,PCB_FLAGS(%r8) testl $TDP_KTHREAD,TD_PFLAGS(%rdi) jnz 2f testb $CPUID_STDEXT_FSGSBASE,cpu_stdext_feature(%rip) jz 2f movl %fs,%eax cmpl $KUF32SEL,%eax jne 1f rdfsbase %rax movq %rax,PCB_FSBASE(%r8) 1: movl %gs,%eax cmpl $KUG32SEL,%eax jne 2f movq %rdx,%r12 movl $MSR_KGSBASE,%ecx /* Read user gs base */ rdmsr shlq $32,%rdx orq %rdx,%rax movq %rax,PCB_GSBASE(%r8) movq %r12,%rdx 2: testl $PCB_DBREGS,PCB_FLAGS(%r8) jnz store_dr /* static predict not taken */ done_store_dr: /* have we used fp, and need a save? */ cmpq %rdi,PCPU(FPCURTHREAD) - jne 3f + jne 2f movq PCB_SAVEFPU(%r8),%r8 clts - cmpl $0,use_xsave + cmpl $0,use_xsave(%rip) jne 1f fxsave (%r8) jmp 2f 1: movq %rdx,%rcx movl xsave_mask,%eax movl xsave_mask+4,%edx .globl ctx_switch_xsave ctx_switch_xsave: /* This is patched to xsaveopt if supported, see fpuinit_bsp1() */ xsave (%r8) movq %rcx,%rdx -2: smsw %ax - orb $CR0_TS,%al - lmsw %ax - xorl %eax,%eax - movq %rax,PCPU(FPCURTHREAD) -3: +2: /* Save is done. Now fire up new thread. Leave old vmspace. */ movq %rsi,%r12 movq %rdi,%r13 movq %rdx,%r15 movq %rsi,%rdi callq pmap_activate_sw SETLK %r15,TD_LOCK(%r13) /* Release the old thread */ sw1: movq TD_PCB(%r12),%r8 #if defined(SCHED_ULE) && defined(SMP) /* Wait for the new thread to become unblocked */ movq $blocked_lock, %rdx 1: movq TD_LOCK(%r12),%rcx cmpq %rcx, %rdx pause je 1b #endif /* * At this point, we've switched address spaces and are ready * to load up the rest of the next context. */ /* Skip loading LDT and user fsbase/gsbase for kthreads */ testl $TDP_KTHREAD,TD_PFLAGS(%r12) jnz do_kthread /* * Load ldt register */ movq TD_PROC(%r12),%rcx cmpq $0, P_MD+MD_LDT(%rcx) jne do_ldt xorl %eax,%eax ld_ldt: lldt %ax /* Restore fs base in GDT */ movl PCB_FSBASE(%r8),%eax movq PCPU(FS32P),%rdx movw %ax,2(%rdx) shrl $16,%eax movb %al,4(%rdx) shrl $8,%eax movb %al,7(%rdx) /* Restore gs base in GDT */ movl PCB_GSBASE(%r8),%eax movq PCPU(GS32P),%rdx movw %ax,2(%rdx) shrl $16,%eax movb %al,4(%rdx) shrl $8,%eax movb %al,7(%rdx) do_kthread: /* Do we need to reload tss ? */ movq PCPU(TSSP),%rax movq PCB_TSSP(%r8),%rdx testq %rdx,%rdx cmovzq PCPU(COMMONTSSP),%rdx cmpq %rax,%rdx jne do_tss done_tss: movq %r8,PCPU(RSP0) movq %r8,PCPU(CURPCB) /* Update the TSS_RSP0 pointer for the next interrupt */ cmpq $~0,PCPU(UCR3) je 1f movq PCPU(PTI_RSP0),%rax movq %rax,TSS_RSP0(%rdx) jmp 2f 1: movq %r8,TSS_RSP0(%rdx) 2: movq %r12,PCPU(CURTHREAD) /* into next thread */ /* Test if debug registers should be restored. */ testl $PCB_DBREGS,PCB_FLAGS(%r8) jnz load_dr /* static predict not taken */ done_load_dr: /* Restore context. */ movq PCB_R15(%r8),%r15 movq PCB_R14(%r8),%r14 movq PCB_R13(%r8),%r13 movq PCB_R12(%r8),%r12 movq PCB_RBP(%r8),%rbp movq PCB_RSP(%r8),%rsp movq PCB_RBX(%r8),%rbx movq PCB_RIP(%r8),%rax movq %rax,(%rsp) + movq PCPU(CURTHREAD),%rdi + call fpu_activate_sw ret /* * We order these strangely for several reasons. * 1: I wanted to use static branch prediction hints * 2: Most athlon64/opteron cpus don't have them. They define * a forward branch as 'predict not taken'. Intel cores have * the 'rep' prefix to invert this. * So, to make it work on both forms of cpu we do the detour. * We use jumps rather than call in order to avoid the stack. */ store_dr: movq %dr7,%rax /* yes, do the save */ movq %dr0,%r15 movq %dr1,%r14 movq %dr2,%r13 movq %dr3,%r12 movq %dr6,%r11 movq %r15,PCB_DR0(%r8) movq %r14,PCB_DR1(%r8) movq %r13,PCB_DR2(%r8) movq %r12,PCB_DR3(%r8) movq %r11,PCB_DR6(%r8) movq %rax,PCB_DR7(%r8) andq $0x0000fc00, %rax /* disable all watchpoints */ movq %rax,%dr7 jmp done_store_dr load_dr: movq %dr7,%rax movq PCB_DR0(%r8),%r15 movq PCB_DR1(%r8),%r14 movq PCB_DR2(%r8),%r13 movq PCB_DR3(%r8),%r12 movq PCB_DR6(%r8),%r11 movq PCB_DR7(%r8),%rcx movq %r15,%dr0 movq %r14,%dr1 /* Preserve reserved bits in %dr7 */ andq $0x0000fc00,%rax andq $~0x0000fc00,%rcx movq %r13,%dr2 movq %r12,%dr3 orq %rcx,%rax movq %r11,%dr6 movq %rax,%dr7 jmp done_load_dr do_tss: movq %rdx,PCPU(TSSP) movq %rdx,%rcx movq PCPU(TSS),%rax movw %cx,2(%rax) shrq $16,%rcx movb %cl,4(%rax) shrq $8,%rcx movb %cl,7(%rax) shrq $8,%rcx movl %ecx,8(%rax) movb $0x89,5(%rax) /* unset busy */ movl $TSSSEL,%eax ltr %ax jmp done_tss do_ldt: movq PCPU(LDT),%rax movq P_MD+MD_LDT_SD(%rcx),%rdx movq %rdx,(%rax) movq P_MD+MD_LDT_SD+8(%rcx),%rdx movq %rdx,8(%rax) movl $LDTSEL,%eax jmp ld_ldt END(cpu_switch) /* * savectx(pcb) * Update pcb, saving current processor state. */ ENTRY(savectx) /* Save caller's return address. */ movq (%rsp),%rax movq %rax,PCB_RIP(%rdi) movq %rbx,PCB_RBX(%rdi) movq %rsp,PCB_RSP(%rdi) movq %rbp,PCB_RBP(%rdi) movq %r12,PCB_R12(%rdi) movq %r13,PCB_R13(%rdi) movq %r14,PCB_R14(%rdi) movq %r15,PCB_R15(%rdi) movq %cr0,%rax movq %rax,PCB_CR0(%rdi) movq %cr2,%rax movq %rax,PCB_CR2(%rdi) movq %cr3,%rax movq %rax,PCB_CR3(%rdi) movq %cr4,%rax movq %rax,PCB_CR4(%rdi) movq %dr0,%rax movq %rax,PCB_DR0(%rdi) movq %dr1,%rax movq %rax,PCB_DR1(%rdi) movq %dr2,%rax movq %rax,PCB_DR2(%rdi) movq %dr3,%rax movq %rax,PCB_DR3(%rdi) movq %dr6,%rax movq %rax,PCB_DR6(%rdi) movq %dr7,%rax movq %rax,PCB_DR7(%rdi) movl $MSR_FSBASE,%ecx rdmsr movl %eax,PCB_FSBASE(%rdi) movl %edx,PCB_FSBASE+4(%rdi) movl $MSR_GSBASE,%ecx rdmsr movl %eax,PCB_GSBASE(%rdi) movl %edx,PCB_GSBASE+4(%rdi) movl $MSR_KGSBASE,%ecx rdmsr movl %eax,PCB_KGSBASE(%rdi) movl %edx,PCB_KGSBASE+4(%rdi) movl $MSR_EFER,%ecx rdmsr movl %eax,PCB_EFER(%rdi) movl %edx,PCB_EFER+4(%rdi) movl $MSR_STAR,%ecx rdmsr movl %eax,PCB_STAR(%rdi) movl %edx,PCB_STAR+4(%rdi) movl $MSR_LSTAR,%ecx rdmsr movl %eax,PCB_LSTAR(%rdi) movl %edx,PCB_LSTAR+4(%rdi) movl $MSR_CSTAR,%ecx rdmsr movl %eax,PCB_CSTAR(%rdi) movl %edx,PCB_CSTAR+4(%rdi) movl $MSR_SF_MASK,%ecx rdmsr movl %eax,PCB_SFMASK(%rdi) movl %edx,PCB_SFMASK+4(%rdi) sgdt PCB_GDT(%rdi) sidt PCB_IDT(%rdi) sldt PCB_LDT(%rdi) str PCB_TR(%rdi) movl $1,%eax ret END(savectx) /* * resumectx(pcb) * Resuming processor state from pcb. */ ENTRY(resumectx) /* Switch to KPML4phys. */ movq KPML4phys,%rax movq %rax,%cr3 /* Force kernel segment registers. */ movl $KDSEL,%eax movw %ax,%ds movw %ax,%es movw %ax,%ss movl $KUF32SEL,%eax movw %ax,%fs movl $KUG32SEL,%eax movw %ax,%gs movl $MSR_FSBASE,%ecx movl PCB_FSBASE(%rdi),%eax movl 4 + PCB_FSBASE(%rdi),%edx wrmsr movl $MSR_GSBASE,%ecx movl PCB_GSBASE(%rdi),%eax movl 4 + PCB_GSBASE(%rdi),%edx wrmsr movl $MSR_KGSBASE,%ecx movl PCB_KGSBASE(%rdi),%eax movl 4 + PCB_KGSBASE(%rdi),%edx wrmsr /* Restore EFER one more time. */ movl $MSR_EFER,%ecx movl PCB_EFER(%rdi),%eax wrmsr /* Restore fast syscall stuff. */ movl $MSR_STAR,%ecx movl PCB_STAR(%rdi),%eax movl 4 + PCB_STAR(%rdi),%edx wrmsr movl $MSR_LSTAR,%ecx movl PCB_LSTAR(%rdi),%eax movl 4 + PCB_LSTAR(%rdi),%edx wrmsr movl $MSR_CSTAR,%ecx movl PCB_CSTAR(%rdi),%eax movl 4 + PCB_CSTAR(%rdi),%edx wrmsr movl $MSR_SF_MASK,%ecx movl PCB_SFMASK(%rdi),%eax wrmsr /* Restore CR0, CR2, CR4 and CR3. */ movq PCB_CR0(%rdi),%rax movq %rax,%cr0 movq PCB_CR2(%rdi),%rax movq %rax,%cr2 movq PCB_CR4(%rdi),%rax movq %rax,%cr4 movq PCB_CR3(%rdi),%rax movq %rax,%cr3 /* Restore descriptor tables. */ lidt PCB_IDT(%rdi) lldt PCB_LDT(%rdi) #define SDT_SYSTSS 9 #define SDT_SYSBSY 11 /* Clear "task busy" bit and reload TR. */ movq PCPU(TSS),%rax andb $(~SDT_SYSBSY | SDT_SYSTSS),5(%rax) movw PCB_TR(%rdi),%ax ltr %ax #undef SDT_SYSTSS #undef SDT_SYSBSY /* Restore debug registers. */ movq PCB_DR0(%rdi),%rax movq %rax,%dr0 movq PCB_DR1(%rdi),%rax movq %rax,%dr1 movq PCB_DR2(%rdi),%rax movq %rax,%dr2 movq PCB_DR3(%rdi),%rax movq %rax,%dr3 movq PCB_DR6(%rdi),%rax movq %rax,%dr6 movq PCB_DR7(%rdi),%rax movq %rax,%dr7 /* Restore other callee saved registers. */ movq PCB_R15(%rdi),%r15 movq PCB_R14(%rdi),%r14 movq PCB_R13(%rdi),%r13 movq PCB_R12(%rdi),%r12 movq PCB_RBP(%rdi),%rbp movq PCB_RSP(%rdi),%rsp movq PCB_RBX(%rdi),%rbx /* Restore return address. */ movq PCB_RIP(%rdi),%rax movq %rax,(%rsp) xorl %eax,%eax ret END(resumectx) Index: head/sys/amd64/amd64/fpu.c =================================================================== --- head/sys/amd64/amd64/fpu.c (revision 335071) +++ head/sys/amd64/amd64/fpu.c (revision 335072) @@ -1,1151 +1,1182 @@ /*- * 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 /* * 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 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"); } #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 xrstor(char *addr, uint64_t mask); void xsave(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 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; /* 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; struct xsave_area_elm_descr { u_int offset; u_int size; } *xsave_area_desc; static void fpusave_xsave(void *addr) { xsave((char *)addr, xsave_mask); } static void fpurestore_xrstor(void *addr) { xrstor((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 *), static) { init_xsave(); return (use_xsave ? fpusave_xsave : fpusave_fxsave); } DEFINE_IFUNC(, void, fpurestore, (void *), static) { init_xsave(); return (use_xsave ? fpurestore_xrstor : fpurestore_fxrstor); } 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; + 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_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_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) { register_t saveintr; int cp[4], i, max_ext_n; fpu_initialstate = malloc(cpu_max_ext_state_size, M_DEVBUF, M_WAITOK | M_ZERO); saveintr = intr_disable(); stop_emulating(); fpusave(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) { 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); /* 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]; } } fpu_save_area_zone = uma_zcreate("FPU_save_area", cpu_max_ext_state_size, NULL, NULL, NULL, NULL, XSAVE_AREA_ALIGN - 1, 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); /* * 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 (PCPU_GET(fpcurthread) == curthread) { + if (PCPU_GET(fpcurthread) == td) { printf("fpudna: fpcurthread == curthread\n"); stop_emulating(); critical_exit(); return; } if (PCPU_GET(fpcurthread) != NULL) { panic("fpudna: fpcurthread = %p (%d), curthread = %p (%d)\n", PCPU_GET(fpcurthread), PCPU_GET(fpcurthread)->td_tid, - curthread, curthread->td_tid); + td, td->td_tid); } - stop_emulating(); - /* - * Record new context early in case frstor causes a trap. - */ - PCPU_SET(fpcurthread, curthread); + restore_fpu_curthread(td); + critical_exit(); +} - fpu_clean_state(); +void fpu_activate_sw(struct thread *td); /* Called from the context switch */ +void +fpu_activate_sw(struct thread *td) +{ - if ((curpcb->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, curpcb->pcb_save, - cpu_max_ext_state_size); - fpurestore(curpcb->pcb_save); - if (curpcb->pcb_initial_fpucw != __INITIAL_FPUCW__) - fldcw(curpcb->pcb_initial_fpucw); - if (PCB_USER_FPU(curpcb)) - set_pcb_flags(curpcb, - PCB_FPUINITDONE | PCB_USERFPUINITDONE); - else - set_pcb_flags(curpcb, PCB_FPUINITDONE); - } else - fpurestore(curpcb->pcb_save); - critical_exit(); + if (lazy_fpu_switch || (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; 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); return (_MC_FPOWNED_PCB); } critical_enter(); 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; } critical_exit(); 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; } } return (owned); } void fpuuserinited(struct thread *td) { struct pcb *pcb; 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; critical_enter(); if (td == PCPU_GET(fpcurthread) && PCB_USER_FPU(pcb)) { error = fpusetxstate(td, xfpustate, xfpustate_size); if (error != 0) { critical_exit(); return (error); } bcopy(addr, get_pcb_user_save_td(td), sizeof(*addr)); fpurestore(get_pcb_user_save_td(td)); critical_exit(); set_pcb_flags(pcb, PCB_FPUINITDONE | PCB_USERFPUINITDONE); } else { critical_exit(); error = fpusetxstate(td, xfpustate, xfpustate_size); if (error != 0) return (error); bcopy(addr, get_pcb_user_save_td(td), sizeof(*addr)); fpuuserinited(td); } return (0); } /* * 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[]; }; 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 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; } 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); return; } 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(); critical_exit(); } 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(); critical_exit(); 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); clear_pcb_flags(pcb, PCB_KERNFPU); } else 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")); } 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); 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) != 0); } /* * FPU save area alloc/free/init utility routines */ struct savefpu * fpu_save_area_alloc(void) { return (uma_zalloc(fpu_save_area_zone, 0)); } 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); }