/*-
* SPDX-License-Identifier: BSD-4-Clause
*
* 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_isa.h"
#include "opt_npx.h"
#include "opt_reset.h"
#include "opt_cpu.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sysent.h>
#include <sys/sf_buf.h>
#include <sys/smp.h>
#include <sys/sched.h>
#include <sys/sysctl.h>
#include <sys/unistd.h>
#include <sys/vnode.h>
#include <sys/vmmeter.h>
#include <machine/cpu.h>
#include <machine/cputypes.h>
#include <machine/md_var.h>
#include <machine/pcb.h>
#include <machine/pcb_ext.h>
#include <machine/smp.h>
#include <machine/vm86.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/vm_kern.h>
#include <vm/vm_page.h>
#include <vm/vm_map.h>
#include <vm/vm_param.h>
_Static_assert(__OFFSETOF_MONITORBUF == offsetof(struct pcpu, pc_monitorbuf),
"__OFFSETOF_MONITORBUF does not correspond with offset of pc_monitorbuf.");
union savefpu *
get_pcb_user_save_td(struct thread *td)
{
vm_offset_t p;
p = td->td_kstack + td->td_kstack_pages * PAGE_SIZE -
roundup2(cpu_max_ext_state_size, XSAVE_AREA_ALIGN);
KASSERT((p % XSAVE_AREA_ALIGN) == 0, ("Unaligned pcb_user_save area"));
return ((union savefpu *)p);
}
union savefpu *
get_pcb_user_save_pcb(struct pcb *pcb)
{
vm_offset_t p;
p = (vm_offset_t)(pcb + 1);
return ((union savefpu *)p);
}
struct pcb *
get_pcb_td(struct thread *td)
{
vm_offset_t p;
p = td->td_kstack + td->td_kstack_pages * PAGE_SIZE -
roundup2(cpu_max_ext_state_size, XSAVE_AREA_ALIGN) -
sizeof(struct pcb);
return ((struct pcb *)p);
}
void *
alloc_fpusave(int flags)
{
void *res;
struct savefpu_ymm *sf;
res = malloc(cpu_max_ext_state_size, M_DEVBUF, flags);
if (use_xsave) {
sf = (struct savefpu_ymm *)res;
bzero(&sf->sv_xstate.sx_hd, sizeof(sf->sv_xstate.sx_hd));
sf->sv_xstate.sx_hd.xstate_bv = xsave_mask;
}
return (res);
}
/*
* 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(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
{
struct proc *p1;
struct pcb *pcb2;
struct mdproc *mdp2;
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 td1's pcb is up to date for user processes. */
if ((td2->td_pflags & TDP_KTHREAD) == 0) {
MPASS(td1 == curthread);
td1->td_pcb->pcb_gs = rgs();
critical_enter();
if (PCPU_GET(fpcurthread) == td1)
npxsave(td1->td_pcb->pcb_save);
critical_exit();
}
/* Point the pcb to the top of the stack */
pcb2 = get_pcb_td(td2);
td2->td_pcb = pcb2;
/* Copy td1's pcb */
bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
/* Properly initialize pcb_save */
pcb2->pcb_save = get_pcb_user_save_pcb(pcb2);
/* Kernel processes start with clean NPX and segment bases. */
if ((td2->td_pflags & TDP_KTHREAD) != 0) {
pcb2->pcb_gs = _udatasel;
set_fsbase(td2, 0);
set_gsbase(td2, 0);
pcb2->pcb_flags &= ~(PCB_NPXINITDONE | PCB_NPXUSERINITDONE |
PCB_KERNNPX | PCB_KERNNPX_THR);
} else {
MPASS((pcb2->pcb_flags & (PCB_KERNNPX | PCB_KERNNPX_THR)) == 0);
bcopy(get_pcb_user_save_td(td1), get_pcb_user_save_pcb(pcb2),
cpu_max_ext_state_size);
}
/* 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 -VM86_STACK_SPACE (-16) is so we can expand the trapframe
* if we go to vm86.
*/
td2->td_frame = (struct trapframe *)((caddr_t)td2->td_pcb -
VM86_STACK_SPACE) - 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.
*/
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.
*/
pcb2->pcb_cr3 = pmap_get_cr3(vmspace_pmap(p2->p_vmspace));
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 + setidt_disp;
/*-
* 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_fork_kthread_handler(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)
{
critical_enter();
if (td == PCPU_GET(fpcurthread))
npxdrop();
critical_exit();
/* 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) {
/* 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)
*/
pmap_trm_free(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)
{
struct pcb *pcb;
struct xstate_hdr *xhdr;
td->td_pcb = pcb = get_pcb_td(td);
td->td_frame = (struct trapframe *)((caddr_t)pcb -
VM86_STACK_SPACE) - 1;
pcb->pcb_ext = NULL;
pcb->pcb_save = get_pcb_user_save_pcb(pcb);
if (use_xsave) {
xhdr = (struct xstate_hdr *)(pcb->pcb_save + 1);
bzero(xhdr, sizeof(*xhdr));
xhdr->xstate_bv = xsave_mask;
}
}
void
cpu_thread_free(struct thread *td)
{
cpu_thread_clean(td);
}
bool
cpu_exec_vmspace_reuse(struct proc *p __unused, vm_map_t map __unused)
{
return (true);
}
int
cpu_procctl(struct thread *td __unused, int idtype __unused, id_t id __unused,
int com __unused, void *data __unused)
{
return (EINVAL);
}
void
cpu_set_syscall_retval(struct thread *td, int error)
{
switch (error) {
case 0:
td->td_frame->tf_eax = td->td_retval[0];
td->td_frame->tf_edx = td->td_retval[1];
td->td_frame->tf_eflags &= ~PSL_C;
break;
case ERESTART:
/*
* Reconstruct pc, assuming lcall $X,y is 7 bytes, int
* 0x80 is 2 bytes. We saved this in tf_err.
*/
td->td_frame->tf_eip -= td->td_frame->tf_err;
break;
case EJUSTRETURN:
break;
default:
td->td_frame->tf_eax = error;
td->td_frame->tf_eflags |= PSL_C;
break;
}
}
/*
* Initialize machine state, mostly pcb and trap frame for a new
* thread, about to return to userspace. Put enough state in the new
* thread's PCB to get it to go back to the fork_return(), which
* finalizes the thread state and handles peculiarities of the first
* return to userspace for the new thread.
*/
void
cpu_copy_thread(struct thread *td, struct thread *td0)
{
struct pcb *pcb2;
/* Point the pcb to the top of the stack. */
pcb2 = td->td_pcb;
/* Ensure that td0's pcb is up to date for user threads. */
if ((td->td_pflags & TDP_KTHREAD) == 0) {
MPASS(td0 == curthread);
td0->td_pcb->pcb_gs = rgs();
critical_enter();
if (PCPU_GET(fpcurthread) == td0)
npxsave(td0->td_pcb->pcb_save);
critical_exit();
}
/*
* Copy the upcall pcb. This loads kernel regs.
* Those not loaded individually below get their default
* values here.
*/
bcopy(td0->td_pcb, pcb2, sizeof(*pcb2));
pcb2->pcb_save = get_pcb_user_save_pcb(pcb2);
/* Kernel threads start with clean NPX and segment bases. */
if ((td->td_pflags & TDP_KTHREAD) != 0) {
pcb2->pcb_gs = _udatasel;
set_fsbase(td, 0);
set_gsbase(td, 0);
pcb2->pcb_flags &= ~(PCB_NPXINITDONE | PCB_NPXUSERINITDONE |
PCB_KERNNPX | PCB_KERNNPX_THR);
} else {
MPASS((pcb2->pcb_flags & (PCB_KERNNPX | PCB_KERNNPX_THR)) == 0);
bcopy(get_pcb_user_save_td(td0), pcb2->pcb_save,
cpu_max_ext_state_size);
}
/*
* Create a new fresh stack for the new thread.
*/
bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
/* If the current thread 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. Otherwise, the new thread will
* receive a (likely unexpected) SIGTRAP when it executes the first
* instruction after returning to userland.
*/
td->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.
*/
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 + setidt_disp;
/*
* If we didn't copy the pcb, we'd need to do the following registers:
* pcb2->pcb_cr3: cloned above.
* 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.
*/
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 starts
* the entry function with the given argument.
*/
void
cpu_set_upcall(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 entry
* 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;
/* Return address sentinel value to stop stack unwinding. */
suword((void *)td->td_frame->tf_esp, 0);
/* Pass the argument to the entry point. */
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);
}
/*
* Get an sf_buf from the freelist. May block if none are available.
*/
void
sf_buf_map(struct sf_buf *sf, int flags)
{
pmap_sf_buf_map(sf);
#ifdef SMP
sf_buf_shootdown(sf, flags);
#endif
}
#ifdef SMP
static void
sf_buf_shootdown_curcpu_cb(pmap_t pmap __unused,
vm_offset_t addr1 __unused, vm_offset_t addr2 __unused)
{
}
void
sf_buf_shootdown(struct sf_buf *sf, int flags)
{
cpuset_t other_cpus;
u_int cpuid;
sched_pin();
cpuid = PCPU_GET(cpuid);
if (!CPU_ISSET(cpuid, &sf->cpumask)) {
CPU_SET(cpuid, &sf->cpumask);
invlpg(sf->kva);
}
if ((flags & SFB_CPUPRIVATE) == 0) {
other_cpus = all_cpus;
CPU_CLR(cpuid, &other_cpus);
CPU_ANDNOT(&other_cpus, &sf->cpumask);
if (!CPU_EMPTY(&other_cpus)) {
CPU_OR(&sf->cpumask, &other_cpus);
smp_masked_invlpg(other_cpus, sf->kva, kernel_pmap,
sf_buf_shootdown_curcpu_cb);
}
}
sched_unpin();
}
#endif
/*
* MD part of sf_buf_free().
*/
int
sf_buf_unmap(struct sf_buf *sf)
{
return (0);
}
static void
sf_buf_invalidate(struct sf_buf *sf)
{
vm_page_t m = sf->m;
/*
* Use pmap_qenter to update the pte for
* existing mapping, in particular, the PAT
* settings are recalculated.
*/
pmap_qenter(sf->kva, &m, 1);
pmap_invalidate_cache_range(sf->kva, sf->kva + PAGE_SIZE);
}
/*
* Invalidate the cache lines that may belong to the page, if
* (possibly old) mapping of the page by sf buffer exists. Returns
* TRUE when mapping was found and cache invalidated.
*/
boolean_t
sf_buf_invalidate_cache(vm_page_t m)
{
return (sf_buf_process_page(m, sf_buf_invalidate));
}
/*
* 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;
}
