/* $NetBSD: uvm_glue.c,v 1.182 2023/10/04 20:34:19 ad Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
* Copyright (c) 1991, 1993, The Regents of the University of California.
*
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* The Mach Operating System project at Carnegie-Mellon University.
*
* 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.
*
* @(#)vm_glue.c 8.6 (Berkeley) 1/5/94
* from: Id: uvm_glue.c,v 1.1.2.8 1998/02/07 01:16:54 chs Exp
*
*
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or
[email protected]
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: uvm_glue.c,v 1.182 2023/10/04 20:34:19 ad Exp $");
#include "opt_kgdb.h"
#include "opt_kstack.h"
#include "opt_uvmhist.h"
/*
* uvm_glue.c: glue functions
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/buf.h>
#include <sys/syncobj.h>
#include <sys/cpu.h>
#include <sys/atomic.h>
#include <sys/lwp.h>
#include <sys/asan.h>
#include <uvm/uvm.h>
#include <uvm/uvm_pdpolicy.h>
#include <uvm/uvm_pgflcache.h>
/*
* uvm_kernacc: test if kernel can access a memory region.
*
* => Currently used only by /dev/kmem driver (dev/mm.c).
*/
bool
uvm_kernacc(void *addr, size_t len, vm_prot_t prot)
{
vaddr_t saddr = trunc_page((vaddr_t)addr);
vaddr_t eaddr = round_page(saddr + len);
bool rv;
vm_map_lock_read(kernel_map);
rv = uvm_map_checkprot(kernel_map, saddr, eaddr, prot);
vm_map_unlock_read(kernel_map);
return rv;
}
#ifdef KGDB
/*
* Change protections on kernel pages from addr to addr+len
* (presumably so debugger can plant a breakpoint).
*
* We force the protection change at the pmap level. If we were
* to use vm_map_protect a change to allow writing would be lazily-
* applied meaning we would still take a protection fault, something
* we really don't want to do. It would also fragment the kernel
* map unnecessarily. We cannot use pmap_protect since it also won't
* enforce a write-enable request. Using pmap_enter is the only way
* we can ensure the change takes place properly.
*/
void
uvm_chgkprot(void *addr, size_t len, int rw)
{
vm_prot_t prot;
paddr_t pa;
vaddr_t sva, eva;
prot = rw == B_READ ? VM_PROT_READ : VM_PROT_READ|VM_PROT_WRITE;
eva = round_page((vaddr_t)addr + len);
for (sva = trunc_page((vaddr_t)addr); sva < eva; sva += PAGE_SIZE) {
/*
* Extract physical address for the page.
*/
if (pmap_extract(pmap_kernel(), sva, &pa) == false)
panic("%s: invalid page", __func__);
pmap_enter(pmap_kernel(), sva, pa, prot, PMAP_WIRED);
}
pmap_update(pmap_kernel());
}
#endif
/*
* uvm_vslock: wire user memory for I/O
*
* - called from physio and sys___sysctl
* - XXXCDC: consider nuking this (or making it a macro?)
*/
int
uvm_vslock(struct vmspace *vs, void *addr, size_t len, vm_prot_t access_type)
{
struct vm_map *map;
vaddr_t start, end;
int error;
map = &vs->vm_map;
start = trunc_page((vaddr_t)addr);
end = round_page((vaddr_t)addr + len);
error = uvm_fault_wire(map, start, end, access_type, 0);
return error;
}
/*
* uvm_vsunlock: unwire user memory wired by uvm_vslock()
*
* - called from physio and sys___sysctl
* - XXXCDC: consider nuking this (or making it a macro?)
*/
void
uvm_vsunlock(struct vmspace *vs, void *addr, size_t len)
{
uvm_fault_unwire(&vs->vm_map, trunc_page((vaddr_t)addr),
round_page((vaddr_t)addr + len));
}
/*
* uvm_proc_fork: fork a virtual address space
*
* - the address space is copied as per parent map's inherit values
*/
void
uvm_proc_fork(struct proc *p1, struct proc *p2, bool shared)
{
if (shared == true) {
p2->p_vmspace = NULL;
uvmspace_share(p1, p2);
} else {
p2->p_vmspace = uvmspace_fork(p1->p_vmspace);
}
cpu_proc_fork(p1, p2);
}
/*
* uvm_lwp_fork: fork a thread
*
* - a new PCB structure is allocated for the child process,
* and filled in by MD layer
* - if specified, the child gets a new user stack described by
* stack and stacksize
* - NOTE: the kernel stack may be at a different location in the child
* process, and thus addresses of automatic variables may be invalid
* after cpu_lwp_fork returns in the child process. We do nothing here
* after cpu_lwp_fork returns.
*/
void
uvm_lwp_fork(struct lwp *l1, struct lwp *l2, void *stack, size_t stacksize,
void (*func)(void *), void *arg)
{
/* Fill stack with magic number. */
kstack_setup_magic(l2);
/*
* cpu_lwp_fork() copy and update the pcb, and make the child ready
* to run. If this is a normal user fork, the child will exit
* directly to user mode via child_return() on its first time
* slice and will not return here. If this is a kernel thread,
* the specified entry point will be executed.
*/
cpu_lwp_fork(l1, l2, stack, stacksize, func, arg);
}
#ifndef USPACE_ALIGN
#define USPACE_ALIGN 0
#endif
static pool_cache_t uvm_uarea_cache;
#if defined(__HAVE_CPU_UAREA_ROUTINES)
static pool_cache_t uvm_uarea_system_cache;
#else
#define uvm_uarea_system_cache uvm_uarea_cache
#endif
static void *
uarea_poolpage_alloc(struct pool *pp, int flags)
{
KASSERT((flags & PR_WAITOK) != 0);
#if defined(PMAP_MAP_POOLPAGE)
while (USPACE == PAGE_SIZE &&
(USPACE_ALIGN == 0 || USPACE_ALIGN == PAGE_SIZE)) {
struct vm_page *pg;
vaddr_t va;
#if defined(PMAP_ALLOC_POOLPAGE)
pg = PMAP_ALLOC_POOLPAGE(0);
#else
pg = uvm_pagealloc(NULL, 0, NULL, 0);
#endif
if (pg == NULL) {
uvm_wait("uarea");
continue;
}
va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg));
KASSERT(va != 0);
return (void *)va;
}
#endif
#if defined(__HAVE_CPU_UAREA_ROUTINES)
void *va = cpu_uarea_alloc(false);
if (va)
return (void *)va;
#endif
return (void *)uvm_km_alloc(kernel_map, pp->pr_alloc->pa_pagesz,
USPACE_ALIGN, UVM_KMF_WIRED | UVM_KMF_WAITVA);
}
static void
uarea_poolpage_free(struct pool *pp, void *addr)
{
#if defined(PMAP_MAP_POOLPAGE)
if (USPACE == PAGE_SIZE &&
(USPACE_ALIGN == 0 || USPACE_ALIGN == PAGE_SIZE)) {
paddr_t pa;
pa = PMAP_UNMAP_POOLPAGE((vaddr_t) addr);
KASSERT(pa != 0);
uvm_pagefree(PHYS_TO_VM_PAGE(pa));
return;
}
#endif
#if defined(__HAVE_CPU_UAREA_ROUTINES)
if (cpu_uarea_free(addr))
return;
#endif
uvm_km_free(kernel_map, (vaddr_t)addr, pp->pr_alloc->pa_pagesz,
UVM_KMF_WIRED);
}
static struct pool_allocator uvm_uarea_allocator = {
.pa_alloc = uarea_poolpage_alloc,
.pa_free = uarea_poolpage_free,
.pa_pagesz = USPACE,
};
#if defined(__HAVE_CPU_UAREA_ROUTINES)
static void *
uarea_system_poolpage_alloc(struct pool *pp, int flags)
{
void * const va = cpu_uarea_alloc(true);
if (va != NULL)
return va;
return (void *)uvm_km_alloc(kernel_map, pp->pr_alloc->pa_pagesz,
USPACE_ALIGN, UVM_KMF_WIRED |
((flags & PR_WAITOK) ? UVM_KMF_WAITVA :
(UVM_KMF_NOWAIT | UVM_KMF_TRYLOCK)));
}
static void
uarea_system_poolpage_free(struct pool *pp, void *addr)
{
if (cpu_uarea_free(addr))
return;
uvm_km_free(kernel_map, (vaddr_t)addr, pp->pr_alloc->pa_pagesz,
UVM_KMF_WIRED);
}
static struct pool_allocator uvm_uarea_system_allocator = {
.pa_alloc = uarea_system_poolpage_alloc,
.pa_free = uarea_system_poolpage_free,
.pa_pagesz = USPACE,
};
#endif /* __HAVE_CPU_UAREA_ROUTINES */
void
uvm_uarea_init(void)
{
int flags = PR_NOTOUCH;
/*
* specify PR_NOALIGN unless the alignment provided by
* the backend (USPACE_ALIGN) is sufficient to provide
* pool page size (UPSACE) alignment.
*/
if ((USPACE_ALIGN == 0 && USPACE != PAGE_SIZE) ||
(USPACE_ALIGN % USPACE) != 0) {
flags |= PR_NOALIGN;
}
uvm_uarea_cache = pool_cache_init(USPACE, USPACE_ALIGN, 0, flags,
"uarea", &uvm_uarea_allocator, IPL_NONE, NULL, NULL, NULL);
#if defined(__HAVE_CPU_UAREA_ROUTINES)
uvm_uarea_system_cache = pool_cache_init(USPACE, USPACE_ALIGN,
0, flags, "uareasys", &uvm_uarea_system_allocator,
IPL_NONE, NULL, NULL, NULL);
#endif
}
/*
* uvm_uarea_alloc: allocate a u-area
*/
vaddr_t
uvm_uarea_alloc(void)
{
return (vaddr_t)pool_cache_get(uvm_uarea_cache, PR_WAITOK);
}
vaddr_t
uvm_uarea_system_alloc(struct cpu_info *ci)
{
#ifdef __HAVE_CPU_UAREA_ALLOC_IDLELWP
if (__predict_false(ci != NULL))
return cpu_uarea_alloc_idlelwp(ci);
#endif
return (vaddr_t)pool_cache_get(uvm_uarea_system_cache, PR_WAITOK);
}
/*
* uvm_uarea_free: free a u-area
*/
void
uvm_uarea_free(vaddr_t uaddr)
{
kasan_mark((void *)uaddr, USPACE, USPACE, 0);
pool_cache_put(uvm_uarea_cache, (void *)uaddr);
}
void
uvm_uarea_system_free(vaddr_t uaddr)
{
kasan_mark((void *)uaddr, USPACE, USPACE, 0);
pool_cache_put(uvm_uarea_system_cache, (void *)uaddr);
}
vaddr_t
uvm_lwp_getuarea(lwp_t *l)
{
return (vaddr_t)l->l_addr - UAREA_PCB_OFFSET;
}
void
uvm_lwp_setuarea(lwp_t *l, vaddr_t addr)
{
l->l_addr = (void *)(addr + UAREA_PCB_OFFSET);
}
/*
* uvm_proc_exit: exit a virtual address space
*
* - borrow proc0's address space because freeing the vmspace
* of the dead process may block.
*/
void
uvm_proc_exit(struct proc *p)
{
struct lwp *l = curlwp; /* XXX */
struct vmspace *ovm;
KASSERT(p == l->l_proc);
ovm = p->p_vmspace;
KASSERT(ovm != NULL);
if (__predict_false(ovm == proc0.p_vmspace))
return;
/*
* borrow proc0's address space.
*/
kpreempt_disable();
pmap_deactivate(l);
p->p_vmspace = proc0.p_vmspace;
pmap_activate(l);
kpreempt_enable();
uvmspace_free(ovm);
}
void
uvm_lwp_exit(struct lwp *l)
{
vaddr_t va = uvm_lwp_getuarea(l);
bool system = (l->l_flag & LW_SYSTEM) != 0;
if (system)
uvm_uarea_system_free(va);
else
uvm_uarea_free(va);
#ifdef DIAGNOSTIC
uvm_lwp_setuarea(l, (vaddr_t)NULL);
#endif
}
/*
* uvm_init_limit: init per-process VM limits
*
* - called for process 0 and then inherited by all others.
*/
void
uvm_init_limits(struct proc *p)
{
/*
* Set up the initial limits on process VM. Set the maximum
* resident set size to be all of (reasonably) available memory.
* This causes any single, large process to start random page
* replacement once it fills memory.
*/
p->p_rlimit[RLIMIT_STACK].rlim_cur = DFLSSIZ;
p->p_rlimit[RLIMIT_STACK].rlim_max = maxsmap;
p->p_rlimit[RLIMIT_DATA].rlim_cur = DFLDSIZ;
p->p_rlimit[RLIMIT_DATA].rlim_max = maxdmap;
p->p_rlimit[RLIMIT_AS].rlim_cur = RLIM_INFINITY;
p->p_rlimit[RLIMIT_AS].rlim_max = RLIM_INFINITY;
p->p_rlimit[RLIMIT_RSS].rlim_cur = MIN(VM_MAXUSER_ADDRESS,
ctob((rlim_t)uvm_availmem(false)));
}
/*
* uvm_scheduler: process zero main loop.
*/
extern struct loadavg averunnable;
void
uvm_scheduler(void)
{
lwp_t *l = curlwp;
lwp_lock(l);
l->l_class = SCHED_FIFO;
lwp_changepri(l, PRI_VM);
lwp_unlock(l);
/* Start the freelist cache. */
uvm_pgflcache_start();
for (;;) {
/* Update legacy stats for post-mortem debugging. */
uvm_update_uvmexp();
/* See if the pagedaemon needs to generate some free pages. */
uvm_kick_pdaemon();
/* Calculate process statistics. */
sched_pstats();
(void)kpause("uvm", false, hz, NULL);
}
}
/*
* uvm_idle: called from the idle loop.
*/
void
uvm_idle(void)
{
struct cpu_info *ci = curcpu();
struct uvm_cpu *ucpu = ci->ci_data.cpu_uvm;
KASSERT(kpreempt_disabled());
uvmpdpol_idle(ucpu);
}
