/*- * Copyright (c) 1982, 1986 The Regents of the University of California. * Copyright (c) 1989, 1990 William Jolitz * Copyright (c) 1994 John Dyson * All rights reserved. * * This code is derived from software contributed to Berkeley by * the Systems Programming Group of the University of Utah Computer * Science Department, and 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. 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: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$ */ #include __FBSDID("$FreeBSD$"); #include "opt_isa.h" #include "opt_npx.h" #include "opt_reset.h" #include "opt_cpu.h" #include "opt_xbox.h" #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 #ifdef CPU_ELAN #include #endif #include #include #include #include #include #include #ifdef PC98 #include #else #include #endif #ifdef XBOX #include #endif #ifndef NSFBUFS #define NSFBUFS (512 + maxusers * 16) #endif static void cpu_reset_real(void); #ifdef SMP static void cpu_reset_proxy(void); static u_int cpu_reset_proxyid; static volatile u_int cpu_reset_proxy_active; #endif static void sf_buf_init(void *arg); SYSINIT(sock_sf, SI_SUB_MBUF, SI_ORDER_ANY, sf_buf_init, NULL); LIST_HEAD(sf_head, sf_buf); /* * A hash table of active sendfile(2) buffers */ static struct sf_head *sf_buf_active; static u_long sf_buf_hashmask; #define SF_BUF_HASH(m) (((m) - vm_page_array) & sf_buf_hashmask) static TAILQ_HEAD(, sf_buf) sf_buf_freelist; static u_int sf_buf_alloc_want; /* * A lock used to synchronize access to the hash table and free list */ static struct mtx sf_buf_lock; extern int _ucodesel, _udatasel; /* * Finish a fork operation, with process p2 nearly set up. * Copy and update the pcb, set up the stack so that the child * ready to run and return to user mode. */ void cpu_fork(td1, p2, td2, flags) register struct thread *td1; register struct proc *p2; struct thread *td2; int flags; { register struct proc *p1; struct pcb *pcb2; struct mdproc *mdp2; #ifdef DEV_NPX register_t savecrit; #endif p1 = td1->td_proc; if ((flags & RFPROC) == 0) { if ((flags & RFMEM) == 0) { /* unshare user LDT */ struct mdproc *mdp1 = &p1->p_md; struct proc_ldt *pldt, *pldt1; mtx_lock_spin(&dt_lock); if ((pldt1 = mdp1->md_ldt) != NULL && pldt1->ldt_refcnt > 1) { pldt = user_ldt_alloc(mdp1, pldt1->ldt_len); if (pldt == NULL) panic("could not copy LDT"); mdp1->md_ldt = pldt; set_user_ldt(mdp1); user_ldt_deref(pldt1); } else mtx_unlock_spin(&dt_lock); } return; } /* Ensure that p1's pcb is up to date. */ if (td1 == curthread) td1->td_pcb->pcb_gs = rgs(); #ifdef DEV_NPX savecrit = intr_disable(); if (PCPU_GET(fpcurthread) == td1) npxsave(&td1->td_pcb->pcb_save); intr_restore(savecrit); #endif /* Point the pcb to the top of the stack */ pcb2 = (struct pcb *)(td2->td_kstack + td2->td_kstack_pages * PAGE_SIZE) - 1; td2->td_pcb = pcb2; /* Copy p1's pcb */ bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); /* Point mdproc and then copy over td1's contents */ mdp2 = &p2->p_md; bcopy(&p1->p_md, mdp2, sizeof(*mdp2)); /* * Create a new fresh stack for the new process. * Copy the trap frame for the return to user mode as if from a * syscall. This copies most of the user mode register values. * The -16 is so we can expand the trapframe if we go to vm86. */ td2->td_frame = (struct trapframe *)((caddr_t)td2->td_pcb - 16) - 1; bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe)); td2->td_frame->tf_eax = 0; /* Child returns zero */ td2->td_frame->tf_eflags &= ~PSL_C; /* success */ td2->td_frame->tf_edx = 1; /* * If the parent process has the trap bit set (i.e. a debugger had * single stepped the process to the system call), we need to clear * the trap flag from the new frame unless the debugger had set PF_FORK * on the parent. Otherwise, the child will receive a (likely * unexpected) SIGTRAP when it executes the first instruction after * returning to userland. */ if ((p1->p_pfsflags & PF_FORK) == 0) td2->td_frame->tf_eflags &= ~PSL_T; /* * Set registers for trampoline to user mode. Leave space for the * return address on stack. These are the kernel mode register values. */ #ifdef PAE pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdpt); #else pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir); #endif pcb2->pcb_edi = 0; pcb2->pcb_esi = (int)fork_return; /* fork_trampoline argument */ pcb2->pcb_ebp = 0; pcb2->pcb_esp = (int)td2->td_frame - sizeof(void *); pcb2->pcb_ebx = (int)td2; /* fork_trampoline argument */ pcb2->pcb_eip = (int)fork_trampoline; pcb2->pcb_psl = PSL_KERNEL; /* ints disabled */ /*- * pcb2->pcb_dr*: cloned above. * pcb2->pcb_savefpu: cloned above. * pcb2->pcb_flags: cloned above. * pcb2->pcb_onfault: cloned above (always NULL here?). * pcb2->pcb_gs: cloned above. * pcb2->pcb_ext: cleared below. */ /* * XXX don't copy the i/o pages. this should probably be fixed. */ pcb2->pcb_ext = 0; /* Copy the LDT, if necessary. */ mtx_lock_spin(&dt_lock); if (mdp2->md_ldt != NULL) { if (flags & RFMEM) { mdp2->md_ldt->ldt_refcnt++; } else { mdp2->md_ldt = user_ldt_alloc(mdp2, mdp2->md_ldt->ldt_len); if (mdp2->md_ldt == NULL) panic("could not copy LDT"); } } mtx_unlock_spin(&dt_lock); /* Setup to release spin count in fork_exit(). */ td2->td_md.md_spinlock_count = 1; td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I; /* * Now, cpu_switch() can schedule the new process. * pcb_esp is loaded pointing to the cpu_switch() stack frame * containing the return address when exiting cpu_switch. * This will normally be to fork_trampoline(), which will have * %ebx loaded with the new proc's pointer. fork_trampoline() * will set up a stack to call fork_return(p, frame); to complete * the return to user-mode. */ } /* * Intercept the return address from a freshly forked process that has NOT * been scheduled yet. * * This is needed to make kernel threads stay in kernel mode. */ void cpu_set_fork_handler(td, func, arg) struct thread *td; void (*func)(void *); void *arg; { /* * Note that the trap frame follows the args, so the function * is really called like this: func(arg, frame); */ td->td_pcb->pcb_esi = (int) func; /* function */ td->td_pcb->pcb_ebx = (int) arg; /* first arg */ } void cpu_exit(struct thread *td) { /* * If this process has a custom LDT, release it. Reset pc->pcb_gs * and %gs before we free it in case they refer to an LDT entry. */ mtx_lock_spin(&dt_lock); if (td->td_proc->p_md.md_ldt) { td->td_pcb->pcb_gs = _udatasel; load_gs(_udatasel); user_ldt_free(td); } else mtx_unlock_spin(&dt_lock); } void cpu_thread_exit(struct thread *td) { #ifdef DEV_NPX if (td == PCPU_GET(fpcurthread)) npxdrop(); #endif /* Disable any hardware breakpoints. */ if (td->td_pcb->pcb_flags & PCB_DBREGS) { reset_dbregs(); td->td_pcb->pcb_flags &= ~PCB_DBREGS; } } void cpu_thread_clean(struct thread *td) { struct pcb *pcb; pcb = td->td_pcb; if (pcb->pcb_ext != NULL) { /* XXXKSE XXXSMP not SMP SAFE.. what locks do we have? */ /* if (pcb->pcb_ext->ext_refcount-- == 1) ?? */ /* * XXX do we need to move the TSS off the allocated pages * before freeing them? (not done here) */ kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ext, ctob(IOPAGES + 1)); pcb->pcb_ext = NULL; } } void cpu_thread_swapin(struct thread *td) { } void cpu_thread_swapout(struct thread *td) { } void cpu_thread_alloc(struct thread *td) { td->td_pcb = (struct pcb *)(td->td_kstack + td->td_kstack_pages * PAGE_SIZE) - 1; td->td_frame = (struct trapframe *)((caddr_t)td->td_pcb - 16) - 1; td->td_pcb->pcb_ext = NULL; } void cpu_thread_free(struct thread *td) { cpu_thread_clean(td); } /* * Initialize machine state (pcb and trap frame) for a new thread about to * upcall. Put enough state in the new thread's PCB to get it to go back * userret(), where we can intercept it again to set the return (upcall) * Address and stack, along with those from upcals that are from other sources * such as those generated in thread_userret() itself. */ void cpu_set_upcall(struct thread *td, struct thread *td0) { struct pcb *pcb2; /* Point the pcb to the top of the stack. */ pcb2 = td->td_pcb; /* * Copy the upcall pcb. This loads kernel regs. * Those not loaded individually below get their default * values here. * * XXXKSE It might be a good idea to simply skip this as * the values of the other registers may be unimportant. * This would remove any requirement for knowing the KSE * at this time (see the matching comment below for * more analysis) (need a good safe default). */ bcopy(td0->td_pcb, pcb2, sizeof(*pcb2)); pcb2->pcb_flags &= ~(PCB_NPXTRAP|PCB_NPXINITDONE); /* * Create a new fresh stack for the new thread. * The -16 is so we can expand the trapframe if we go to vm86. * Don't forget to set this stack value into whatever supplies * the address for the fault handlers. * The contexts are filled in at the time we actually DO the * upcall as only then do we know which KSE we got. */ bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); /* * Set registers for trampoline to user mode. Leave space for the * return address on stack. These are the kernel mode register values. */ #ifdef PAE pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pdpt); #else pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pdir); #endif pcb2->pcb_edi = 0; pcb2->pcb_esi = (int)fork_return; /* trampoline arg */ pcb2->pcb_ebp = 0; pcb2->pcb_esp = (int)td->td_frame - sizeof(void *); /* trampoline arg */ pcb2->pcb_ebx = (int)td; /* trampoline arg */ pcb2->pcb_eip = (int)fork_trampoline; pcb2->pcb_psl &= ~(PSL_I); /* interrupts must be disabled */ pcb2->pcb_gs = rgs(); /* * If we didn't copy the pcb, we'd need to do the following registers: * pcb2->pcb_dr*: cloned above. * pcb2->pcb_savefpu: cloned above. * pcb2->pcb_flags: cloned above. * pcb2->pcb_onfault: cloned above (always NULL here?). * pcb2->pcb_gs: cloned above. XXXKSE ??? * pcb2->pcb_ext: cleared below. */ pcb2->pcb_ext = NULL; /* Setup to release spin count in fork_exit(). */ td->td_md.md_spinlock_count = 1; td->td_md.md_saved_flags = PSL_KERNEL | PSL_I; } /* * Set that machine state for performing an upcall that has to * be done in thread_userret() so that those upcalls generated * in thread_userret() itself can be done as well. */ void cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg, stack_t *stack) { /* * Do any extra cleaning that needs to be done. * The thread may have optional components * that are not present in a fresh thread. * This may be a recycled thread so make it look * as though it's newly allocated. */ cpu_thread_clean(td); /* * Set the trap frame to point at the beginning of the uts * function. */ td->td_frame->tf_ebp = 0; td->td_frame->tf_esp = (((int)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4; td->td_frame->tf_eip = (int)entry; /* * Pass the address of the mailbox for this kse to the uts * function as a parameter on the stack. */ suword((void *)(td->td_frame->tf_esp + sizeof(void *)), (int)arg); } int cpu_set_user_tls(struct thread *td, void *tls_base) { struct segment_descriptor sd; uint32_t base; /* * Construct a descriptor and store it in the pcb for * the next context switch. Also store it in the gdt * so that the load of tf_fs into %fs will activate it * at return to userland. */ base = (uint32_t)tls_base; sd.sd_lobase = base & 0xffffff; sd.sd_hibase = (base >> 24) & 0xff; sd.sd_lolimit = 0xffff; /* 4GB limit, wraps around */ sd.sd_hilimit = 0xf; sd.sd_type = SDT_MEMRWA; sd.sd_dpl = SEL_UPL; sd.sd_p = 1; sd.sd_xx = 0; sd.sd_def32 = 1; sd.sd_gran = 1; critical_enter(); /* set %gs */ td->td_pcb->pcb_gsd = sd; if (td == curthread) { PCPU_GET(fsgs_gdt)[1] = sd; load_gs(GSEL(GUGS_SEL, SEL_UPL)); } critical_exit(); return (0); } /* * Convert kernel VA to physical address */ vm_paddr_t kvtop(void *addr) { vm_paddr_t pa; pa = pmap_kextract((vm_offset_t)addr); if (pa == 0) panic("kvtop: zero page frame"); return (pa); } #ifdef SMP static void cpu_reset_proxy() { cpu_reset_proxy_active = 1; while (cpu_reset_proxy_active == 1) ; /* Wait for other cpu to see that we've started */ stop_cpus((1<RESCFG = 1; #endif if (cpu == CPU_GEODE1100) { /* Attempt Geode's own reset */ outl(0xcf8, 0x80009044ul); outl(0xcfc, 0xf); } #ifdef PC98 /* * Attempt to do a CPU reset via CPU reset port. */ if ((inb(0x35) & 0xa0) != 0xa0) { outb(0x37, 0x0f); /* SHUT0 = 0. */ outb(0x37, 0x0b); /* SHUT1 = 0. */ } outb(0xf0, 0x00); /* Reset. */ #else #if !defined(BROKEN_KEYBOARD_RESET) /* * Attempt to do a CPU reset via the keyboard controller, * do not turn off GateA20, as any machine that fails * to do the reset here would then end up in no man's land. */ outb(IO_KBD + 4, 0xFE); DELAY(500000); /* wait 0.5 sec to see if that did it */ #endif /* * Attempt to force a reset via the Reset Control register at * I/O port 0xcf9. Bit 2 forces a system reset when it * transitions from 0 to 1. Bit 1 selects the type of reset * to attempt: 0 selects a "soft" reset, and 1 selects a * "hard" reset. We try a "hard" reset. The first write sets * bit 1 to select a "hard" reset and clears bit 2. The * second write forces a 0 -> 1 transition in bit 2 to trigger * a reset. */ outb(0xcf9, 0x2); outb(0xcf9, 0x6); DELAY(500000); /* wait 0.5 sec to see if that did it */ /* * Attempt to force a reset via the Fast A20 and Init register * at I/O port 0x92. Bit 1 serves as an alternate A20 gate. * Bit 0 asserts INIT# when set to 1. We are careful to only * preserve bit 1 while setting bit 0. We also must clear bit * 0 before setting it if it isn't already clear. */ b = inb(0x92); if (b != 0xff) { if ((b & 0x1) != 0) outb(0x92, b & 0xfe); outb(0x92, b | 0x1); DELAY(500000); /* wait 0.5 sec to see if that did it */ } #endif /* PC98 */ printf("No known reset method worked, attempting CPU shutdown\n"); DELAY(1000000); /* wait 1 sec for printf to complete */ /* Wipe the IDT. */ null_idt.rd_limit = 0; null_idt.rd_base = 0; lidt(&null_idt); /* "good night, sweet prince .... " */ breakpoint(); /* NOTREACHED */ while(1); } /* * Allocate a pool of sf_bufs (sendfile(2) or "super-fast" if you prefer. :-)) */ static void sf_buf_init(void *arg) { struct sf_buf *sf_bufs; vm_offset_t sf_base; int i; nsfbufs = NSFBUFS; TUNABLE_INT_FETCH("kern.ipc.nsfbufs", &nsfbufs); sf_buf_active = hashinit(nsfbufs, M_TEMP, &sf_buf_hashmask); TAILQ_INIT(&sf_buf_freelist); sf_base = kmem_alloc_nofault(kernel_map, nsfbufs * PAGE_SIZE); sf_bufs = malloc(nsfbufs * sizeof(struct sf_buf), M_TEMP, M_NOWAIT | M_ZERO); for (i = 0; i < nsfbufs; i++) { sf_bufs[i].kva = sf_base + i * PAGE_SIZE; TAILQ_INSERT_TAIL(&sf_buf_freelist, &sf_bufs[i], free_entry); } sf_buf_alloc_want = 0; mtx_init(&sf_buf_lock, "sf_buf", NULL, MTX_DEF); } /* * Get an sf_buf from the freelist. May block if none are available. */ struct sf_buf * sf_buf_alloc(struct vm_page *m, int flags) { pt_entry_t opte, *ptep; struct sf_head *hash_list; struct sf_buf *sf; #ifdef SMP cpumask_t cpumask, other_cpus; #endif int error; KASSERT(curthread->td_pinned > 0 || (flags & SFB_CPUPRIVATE) == 0, ("sf_buf_alloc(SFB_CPUPRIVATE): curthread not pinned")); hash_list = &sf_buf_active[SF_BUF_HASH(m)]; mtx_lock(&sf_buf_lock); LIST_FOREACH(sf, hash_list, list_entry) { if (sf->m == m) { sf->ref_count++; if (sf->ref_count == 1) { TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry); nsfbufsused++; nsfbufspeak = imax(nsfbufspeak, nsfbufsused); } #ifdef SMP goto shootdown; #else goto done; #endif } } while ((sf = TAILQ_FIRST(&sf_buf_freelist)) == NULL) { if (flags & SFB_NOWAIT) goto done; sf_buf_alloc_want++; mbstat.sf_allocwait++; error = msleep(&sf_buf_freelist, &sf_buf_lock, (flags & SFB_CATCH) ? PCATCH | PVM : PVM, "sfbufa", 0); sf_buf_alloc_want--; /* * If we got a signal, don't risk going back to sleep. */ if (error) goto done; } TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry); if (sf->m != NULL) LIST_REMOVE(sf, list_entry); LIST_INSERT_HEAD(hash_list, sf, list_entry); sf->ref_count = 1; sf->m = m; nsfbufsused++; nsfbufspeak = imax(nsfbufspeak, nsfbufsused); /* * Update the sf_buf's virtual-to-physical mapping, flushing the * virtual address from the TLB. Since the reference count for * the sf_buf's old mapping was zero, that mapping is not * currently in use. Consequently, there is no need to exchange * the old and new PTEs atomically, even under PAE. */ ptep = vtopte(sf->kva); opte = *ptep; *ptep = VM_PAGE_TO_PHYS(m) | pgeflag | PG_RW | PG_V; /* * Avoid unnecessary TLB invalidations: If the sf_buf's old * virtual-to-physical mapping was not used, then any processor * that has invalidated the sf_buf's virtual address from its TLB * since the last used mapping need not invalidate again. */ #ifdef SMP if ((opte & (PG_V | PG_A)) == (PG_V | PG_A)) sf->cpumask = 0; shootdown: sched_pin(); cpumask = PCPU_GET(cpumask); if ((sf->cpumask & cpumask) == 0) { sf->cpumask |= cpumask; invlpg(sf->kva); } if ((flags & SFB_CPUPRIVATE) == 0) { other_cpus = PCPU_GET(other_cpus) & ~sf->cpumask; if (other_cpus != 0) { sf->cpumask |= other_cpus; smp_masked_invlpg(other_cpus, sf->kva); } } sched_unpin(); #else if ((opte & (PG_V | PG_A)) == (PG_V | PG_A)) pmap_invalidate_page(kernel_pmap, sf->kva); #endif done: mtx_unlock(&sf_buf_lock); return (sf); } /* * Remove a reference from the given sf_buf, adding it to the free * list when its reference count reaches zero. A freed sf_buf still, * however, retains its virtual-to-physical mapping until it is * recycled or reactivated by sf_buf_alloc(9). */ void sf_buf_free(struct sf_buf *sf) { mtx_lock(&sf_buf_lock); sf->ref_count--; if (sf->ref_count == 0) { TAILQ_INSERT_TAIL(&sf_buf_freelist, sf, free_entry); nsfbufsused--; if (sf_buf_alloc_want > 0) wakeup_one(&sf_buf_freelist); } mtx_unlock(&sf_buf_lock); } /* * Software interrupt handler for queued VM system processing. */ void swi_vm(void *dummy) { if (busdma_swi_pending != 0) busdma_swi(); } /* * Tell whether this address is in some physical memory region. * Currently used by the kernel coredump code in order to avoid * dumping the ``ISA memory hole'' which could cause indefinite hangs, * or other unpredictable behaviour. */ int is_physical_memory(vm_paddr_t addr) { #ifdef DEV_ISA /* The ISA ``memory hole''. */ if (addr >= 0xa0000 && addr < 0x100000) return 0; #endif /* * stuff other tests for known memory-mapped devices (PCI?) * here */ return 1; }