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pmap.c
6744 lines (5864 loc) · 165 KB
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pmap.c
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/* $NetBSD: pmap.c,v 1.415 2022/05/13 09:39:40 riastradh Exp $ */
/*
* Copyright (c) 2008, 2010, 2016, 2017, 2019, 2020 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Andrew Doran, and by Maxime Villard.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* Copyright (c) 2007 Manuel Bouyer.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
/*
* Copyright (c) 2006 Mathieu Ropert <mro@adviseo.fr>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* Copyright 2001 (c) Wasabi Systems, Inc.
* All rights reserved.
*
* Written by Frank van der Linden for Wasabi Systems, Inc.
*
* 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 for the NetBSD Project by
* Wasabi Systems, Inc.
* 4. The name of Wasabi Systems, Inc. may not be used to endorse
* or promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
* 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.
*/
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.415 2022/05/13 09:39:40 riastradh Exp $");
#include "opt_user_ldt.h"
#include "opt_lockdebug.h"
#include "opt_multiprocessor.h"
#include "opt_xen.h"
#include "opt_svs.h"
#include "opt_kaslr.h"
#define __MUTEX_PRIVATE /* for assertions */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/pool.h>
#include <sys/kernel.h>
#include <sys/atomic.h>
#include <sys/cpu.h>
#include <sys/intr.h>
#include <sys/xcall.h>
#include <sys/kcore.h>
#include <sys/kmem.h>
#include <sys/asan.h>
#include <sys/msan.h>
#include <sys/entropy.h>
#include <uvm/uvm.h>
#include <uvm/pmap/pmap_pvt.h>
#include <dev/isa/isareg.h>
#include <machine/specialreg.h>
#include <machine/gdt.h>
#include <machine/isa_machdep.h>
#include <machine/cpuvar.h>
#include <machine/cputypes.h>
#include <x86/pmap_pv.h>
#include <x86/i82489reg.h>
#include <x86/i82489var.h>
#ifdef XEN
#include <xen/include/public/xen.h>
#include <xen/hypervisor.h>
#include <xen/xenpmap.h>
#endif
#ifdef __HAVE_DIRECT_MAP
#include <crypto/nist_hash_drbg/nist_hash_drbg.h>
#endif
/*
* general info:
*
* - for an explanation of how the x86 MMU hardware works see
* the comments in <machine/pte.h>.
*
* - for an explanation of the general memory structure used by
* this pmap (including the recursive mapping), see the comments
* in <machine/pmap.h>.
*
* this file contains the code for the "pmap module." the module's
* job is to manage the hardware's virtual to physical address mappings.
* note that there are two levels of mapping in the VM system:
*
* [1] the upper layer of the VM system uses vm_map's and vm_map_entry's
* to map ranges of virtual address space to objects/files. for
* example, the vm_map may say: "map VA 0x1000 to 0x22000 read-only
* to the file /bin/ls starting at offset zero." note that
* the upper layer mapping is not concerned with how individual
* vm_pages are mapped.
*
* [2] the lower layer of the VM system (the pmap) maintains the mappings
* from virtual addresses. it is concerned with which vm_page is
* mapped where. for example, when you run /bin/ls and start
* at page 0x1000 the fault routine may lookup the correct page
* of the /bin/ls file and then ask the pmap layer to establish
* a mapping for it.
*
* note that information in the lower layer of the VM system can be
* thrown away since it can easily be reconstructed from the info
* in the upper layer.
*
* data structures we use include:
*
* - struct pmap: describes the address space of one thread
* - struct pmap_page: describes one pv-tracked page, without
* necessarily a corresponding vm_page
* - struct pv_entry: describes one <PMAP,VA> mapping of a PA
* - pmap_page::pp_pvlist: there is one list per pv-tracked page of
* physical memory. the pp_pvlist points to a list of pv_entry
* structures which describe all the <PMAP,VA> pairs that this
* page is mapped in. this is critical for page based operations
* such as pmap_page_protect() [change protection on _all_ mappings
* of a page]
*/
/*
* Locking
*
* We have the following locks that we must deal with, listed in the order
* that they are acquired:
*
* pg->uobject->vmobjlock, pg->uanon->an_lock
*
* For managed pages, these per-object locks are taken by the VM system
* before calling into the pmap module - either a read or write hold.
* The lock hold prevent pages from changing identity while the pmap is
* operating on them. For example, the same lock is held across a call
* to pmap_remove() and the following call to pmap_update(), so that a
* page does not gain a new identity while its TLB visibility is stale.
*
* pmap->pm_lock
*
* This lock protects the fields in the pmap structure including the
* non-kernel PDEs in the PDP, the PTEs, and PTPs and connected data
* structures. For modifying unmanaged kernel PTEs it is not needed as
* kernel PDEs are never freed, and the kernel is expected to be self
* consistent (and the lock can't be taken for unmanaged kernel PTEs,
* because they can be modified from interrupt context).
*
* pmaps_lock
*
* This lock protects the list of active pmaps (headed by "pmaps").
* It's acquired when adding or removing pmaps or adjusting kernel PDEs.
*
* pp_lock
*
* This per-page lock protects PV entry lists and the embedded PV entry
* in each vm_page, allowing for concurrent operation on pages by
* different pmaps. This is a spin mutex at IPL_VM, because at the
* points it is taken context switching is usually not tolerable, and
* spin mutexes must block out interrupts that could take kernel_lock.
*/
/* uvm_object is abused here to index pmap_pages; make assertions happy. */
#ifdef DIAGNOSTIC
#define PMAP_DUMMY_LOCK(pm) rw_enter(&(pm)->pm_dummy_lock, RW_WRITER)
#define PMAP_DUMMY_UNLOCK(pm) rw_exit(&(pm)->pm_dummy_lock)
#else
#define PMAP_DUMMY_LOCK(pm)
#define PMAP_DUMMY_UNLOCK(pm)
#endif
static const struct uvm_pagerops pmap_pager = {
/* nothing */
};
const vaddr_t ptp_masks[] = PTP_MASK_INITIALIZER;
const vaddr_t ptp_frames[] = PTP_FRAME_INITIALIZER;
const int ptp_shifts[] = PTP_SHIFT_INITIALIZER;
const long nkptpmax[] = NKPTPMAX_INITIALIZER;
const long nbpd[] = NBPD_INITIALIZER;
#ifdef i386
pd_entry_t * const normal_pdes[] = PDES_INITIALIZER;
#else
pd_entry_t *normal_pdes[3];
#endif
long nkptp[] = NKPTP_INITIALIZER;
struct pmap_head pmaps;
kmutex_t pmaps_lock __cacheline_aligned;
struct pcpu_area *pcpuarea __read_mostly;
static vaddr_t pmap_maxkvaddr;
/*
* Misc. event counters.
*/
struct evcnt pmap_iobmp_evcnt;
struct evcnt pmap_ldt_evcnt;
/*
* PAT
*/
static bool cpu_pat_enabled __read_mostly = false;
/*
* Global data structures
*/
static struct pmap kernel_pmap_store __cacheline_aligned; /* kernel's pmap */
struct pmap *const kernel_pmap_ptr = &kernel_pmap_store;
static rb_tree_t pmap_kernel_rb __cacheline_aligned;
struct bootspace bootspace __read_mostly;
struct slotspace slotspace __read_mostly;
/* Set to PTE_NX if supported. */
pd_entry_t pmap_pg_nx __read_mostly = 0;
/* Set to PTE_G if supported. */
pd_entry_t pmap_pg_g __read_mostly = 0;
/* Set to true if large pages are supported. */
int pmap_largepages __read_mostly = 0;
paddr_t lowmem_rsvd __read_mostly;
paddr_t avail_start __read_mostly; /* PA of first available physical page */
paddr_t avail_end __read_mostly; /* PA of last available physical page */
#ifdef XENPV
paddr_t pmap_pa_start; /* PA of first physical page for this domain */
paddr_t pmap_pa_end; /* PA of last physical page for this domain */
#endif
#define VM_PAGE_TO_PP(pg) (&(pg)->mdpage.mp_pp)
#define PMAP_CHECK_PP(pp) \
KASSERTMSG((pp)->pp_lock.mtx_ipl._ipl == IPL_VM, "bad pmap_page %p", pp)
#define PAGE_ALIGNED(pp) \
__builtin_assume_aligned((void *)(pp), PAGE_SIZE)
/*
* Other data structures
*/
static pt_entry_t protection_codes[8] __read_mostly;
static bool pmap_initialized __read_mostly = false; /* pmap_init done yet? */
/*
* The following two vaddr_t's are used during system startup to keep track of
* how much of the kernel's VM space we have used. Once the system is started,
* the management of the remaining kernel VM space is turned over to the
* kernel_map vm_map.
*/
static vaddr_t virtual_avail __read_mostly; /* VA of first free KVA */
static vaddr_t virtual_end __read_mostly; /* VA of last free KVA */
#ifndef XENPV
/*
* LAPIC virtual address, and fake physical address.
*/
volatile vaddr_t local_apic_va __read_mostly;
paddr_t local_apic_pa __read_mostly;
#endif
/*
* pool that pmap structures are allocated from
*/
struct pool_cache pmap_cache;
static int pmap_ctor(void *, void *, int);
static void pmap_dtor(void *, void *);
/*
* pv_page cache
*/
static struct pool_cache pmap_pvp_cache;
#ifdef __HAVE_DIRECT_MAP
vaddr_t pmap_direct_base __read_mostly;
vaddr_t pmap_direct_end __read_mostly;
#endif
#ifndef __HAVE_DIRECT_MAP
/*
* Special VAs and the PTEs that map them
*/
static pt_entry_t *early_zero_pte;
static void pmap_vpage_cpualloc(struct cpu_info *);
#ifdef XENPV
char *early_zerop; /* also referenced from xen_locore() */
#else
static char *early_zerop;
#endif
#endif
int pmap_enter_default(pmap_t, vaddr_t, paddr_t, vm_prot_t, u_int);
/* PDP pool and its callbacks */
static struct pool pmap_pdp_pool;
static void pmap_pdp_init(pd_entry_t *);
static void pmap_pdp_fini(pd_entry_t *);
#ifdef PAE
/* need to allocate items of 4 pages */
static void *pmap_pdp_alloc(struct pool *, int);
static void pmap_pdp_free(struct pool *, void *);
static struct pool_allocator pmap_pdp_allocator = {
.pa_alloc = pmap_pdp_alloc,
.pa_free = pmap_pdp_free,
.pa_pagesz = PAGE_SIZE * PDP_SIZE,
};
#endif
extern vaddr_t idt_vaddr;
extern paddr_t idt_paddr;
extern vaddr_t gdt_vaddr;
extern paddr_t gdt_paddr;
extern vaddr_t ldt_vaddr;
extern paddr_t ldt_paddr;
#ifdef i386
/* stuff to fix the pentium f00f bug */
extern vaddr_t pentium_idt_vaddr;
#endif
/* Array of freshly allocated PTPs, for pmap_get_ptp(). */
struct pmap_ptparray {
struct vm_page *pg[PTP_LEVELS + 1];
bool alloced[PTP_LEVELS + 1];
};
/*
* PV entries are allocated in page-sized chunks and cached per-pmap to
* avoid intense pressure on memory allocators.
*/
struct pv_page {
LIST_HEAD(, pv_entry) pvp_pves;
LIST_ENTRY(pv_page) pvp_list;
long pvp_nfree;
struct pmap *pvp_pmap;
};
#define PVE_PER_PVP ((PAGE_SIZE / sizeof(struct pv_entry)) - 1)
/*
* PV tree prototypes
*/
static int pmap_compare_key(void *, const void *, const void *);
static int pmap_compare_nodes(void *, const void *, const void *);
/* Read-black tree */
static const rb_tree_ops_t pmap_rbtree_ops = {
.rbto_compare_nodes = pmap_compare_nodes,
.rbto_compare_key = pmap_compare_key,
.rbto_node_offset = offsetof(struct pv_entry, pve_rb),
.rbto_context = NULL
};
/*
* Local prototypes
*/
#ifdef __HAVE_PCPU_AREA
static void pmap_init_pcpu(void);
#endif
#ifdef __HAVE_DIRECT_MAP
static void pmap_init_directmap(struct pmap *);
#endif
#if !defined(XENPV)
static void pmap_remap_global(void);
#endif
#ifndef XENPV
static void pmap_init_lapic(void);
static void pmap_remap_largepages(void);
#endif
static int pmap_get_ptp(struct pmap *, struct pmap_ptparray *, vaddr_t, int,
struct vm_page **);
static void pmap_unget_ptp(struct pmap *, struct pmap_ptparray *);
static void pmap_install_ptp(struct pmap *, struct pmap_ptparray *, vaddr_t,
pd_entry_t * const *);
static struct vm_page *pmap_find_ptp(struct pmap *, vaddr_t, int);
static void pmap_freepage(struct pmap *, struct vm_page *, int);
static void pmap_free_ptp(struct pmap *, struct vm_page *, vaddr_t,
pt_entry_t *, pd_entry_t * const *);
static bool pmap_remove_pte(struct pmap *, struct vm_page *, pt_entry_t *,
vaddr_t);
static void pmap_remove_ptes(struct pmap *, struct vm_page *, vaddr_t, vaddr_t,
vaddr_t);
static int pmap_pvp_ctor(void *, void *, int);
static void pmap_pvp_dtor(void *, void *);
static struct pv_entry *pmap_alloc_pv(struct pmap *);
static void pmap_free_pv(struct pmap *, struct pv_entry *);
static void pmap_drain_pv(struct pmap *);
static void pmap_alloc_level(struct pmap *, vaddr_t, long *);
static void pmap_load1(struct lwp *, struct pmap *, struct pmap *);
static void pmap_reactivate(struct pmap *);
/*
* p m a p h e l p e r f u n c t i o n s
*/
static inline void
pmap_stats_update(struct pmap *pmap, int resid_diff, int wired_diff)
{
KASSERT(cold || mutex_owned(&pmap->pm_lock));
pmap->pm_stats.resident_count += resid_diff;
pmap->pm_stats.wired_count += wired_diff;
}
static inline void
pmap_stats_update_bypte(struct pmap *pmap, pt_entry_t npte, pt_entry_t opte)
{
int resid_diff = ((npte & PTE_P) ? 1 : 0) - ((opte & PTE_P) ? 1 : 0);
int wired_diff = ((npte & PTE_WIRED) ? 1 : 0) - ((opte & PTE_WIRED) ? 1 : 0);
KASSERT((npte & (PTE_P | PTE_WIRED)) != PTE_WIRED);
KASSERT((opte & (PTE_P | PTE_WIRED)) != PTE_WIRED);
pmap_stats_update(pmap, resid_diff, wired_diff);
}
/*
* ptp_to_pmap: lookup pmap by ptp
*/
static inline struct pmap *
ptp_to_pmap(struct vm_page *ptp)
{
struct pmap *pmap;
if (ptp == NULL) {
return pmap_kernel();
}
pmap = (struct pmap *)ptp->uobject;
KASSERT(pmap != NULL);
KASSERT(&pmap->pm_obj[0] == ptp->uobject);
return pmap;
}
static inline struct pv_pte *
pve_to_pvpte(struct pv_entry *pve)
{
if (pve == NULL)
return NULL;
KASSERT((void *)&pve->pve_pte == (void *)pve);
return &pve->pve_pte;
}
static inline struct pv_entry *
pvpte_to_pve(struct pv_pte *pvpte)
{
struct pv_entry *pve = (void *)pvpte;
KASSERT(pve_to_pvpte(pve) == pvpte);
return pve;
}
/*
* Return true if the pmap page has an embedded PV entry.
*/
static inline bool
pv_pte_embedded(struct pmap_page *pp)
{
KASSERT(mutex_owned(&pp->pp_lock));
return (bool)((vaddr_t)pp->pp_pte.pte_ptp | pp->pp_pte.pte_va);
}
/*
* pv_pte_first, pv_pte_next: PV list iterator.
*/
static inline struct pv_pte *
pv_pte_first(struct pmap_page *pp)
{
KASSERT(mutex_owned(&pp->pp_lock));
if (pv_pte_embedded(pp)) {
return &pp->pp_pte;
}
return pve_to_pvpte(LIST_FIRST(&pp->pp_pvlist));
}
static inline struct pv_pte *
pv_pte_next(struct pmap_page *pp, struct pv_pte *pvpte)
{
KASSERT(mutex_owned(&pp->pp_lock));
KASSERT(pvpte != NULL);
if (pvpte == &pp->pp_pte) {
return pve_to_pvpte(LIST_FIRST(&pp->pp_pvlist));
}
return pve_to_pvpte(LIST_NEXT(pvpte_to_pve(pvpte), pve_list));
}
static inline uint8_t
pmap_pte_to_pp_attrs(pt_entry_t pte)
{
uint8_t ret = 0;
if (pte & PTE_D)
ret |= PP_ATTRS_D;
if (pte & PTE_A)
ret |= PP_ATTRS_A;
if (pte & PTE_W)
ret |= PP_ATTRS_W;
return ret;
}
static inline pt_entry_t
pmap_pp_attrs_to_pte(uint8_t attrs)
{
pt_entry_t pte = 0;
if (attrs & PP_ATTRS_D)
pte |= PTE_D;
if (attrs & PP_ATTRS_A)
pte |= PTE_A;
if (attrs & PP_ATTRS_W)
pte |= PTE_W;
return pte;
}
/*
* pmap_is_curpmap: is this pmap the one currently loaded [in %cr3]?
* of course the kernel is always loaded
*/
bool
pmap_is_curpmap(struct pmap *pmap)
{
return ((pmap == pmap_kernel()) || (pmap == curcpu()->ci_pmap));
}
inline void
pmap_reference(struct pmap *pmap)
{
atomic_inc_uint(&pmap->pm_obj[0].uo_refs);
}
/*
* rbtree: compare two nodes.
*/
static int
pmap_compare_nodes(void *context, const void *n1, const void *n2)
{
const struct pv_entry *pve1 = n1;
const struct pv_entry *pve2 = n2;
KASSERT(pve1->pve_pte.pte_ptp == pve2->pve_pte.pte_ptp);
if (pve1->pve_pte.pte_va < pve2->pve_pte.pte_va) {
return -1;
}
if (pve1->pve_pte.pte_va > pve2->pve_pte.pte_va) {
return 1;
}
return 0;
}
/*
* rbtree: compare a node and a key.
*/
static int
pmap_compare_key(void *context, const void *n, const void *k)
{
const struct pv_entry *pve = n;
const vaddr_t key = (vaddr_t)k;
if (pve->pve_pte.pte_va < key) {
return -1;
}
if (pve->pve_pte.pte_va > key) {
return 1;
}
return 0;
}
/*
* pmap_ptp_range_set: abuse ptp->uanon to record minimum VA of PTE
*/
static inline void
pmap_ptp_range_set(struct vm_page *ptp, vaddr_t va)
{
vaddr_t *min = (vaddr_t *)&ptp->uanon;
if (va < *min) {
*min = va;
}
}
/*
* pmap_ptp_range_clip: abuse ptp->uanon to clip range of PTEs to remove
*/
static inline void
pmap_ptp_range_clip(struct vm_page *ptp, vaddr_t *startva, pt_entry_t **pte)
{
vaddr_t sclip;
if (ptp == NULL) {
return;
}
sclip = (vaddr_t)ptp->uanon;
sclip = (*startva < sclip ? sclip : *startva);
*pte += (sclip - *startva) / PAGE_SIZE;
*startva = sclip;
}
/*
* pmap_map_ptes: map a pmap's PTEs into KVM and lock them in
*
* there are several pmaps involved. some or all of them might be same.
*
* - the pmap given by the first argument
* our caller wants to access this pmap's PTEs.
*
* - pmap_kernel()
* the kernel pmap. note that it only contains the kernel part
* of the address space which is shared by any pmap. ie. any
* pmap can be used instead of pmap_kernel() for our purpose.
*
* - ci->ci_pmap
* pmap currently loaded on the cpu.
*
* - vm_map_pmap(&curproc->p_vmspace->vm_map)
* current process' pmap.
*
* => caller must lock pmap first (if not the kernel pmap)
* => must be undone with pmap_unmap_ptes before returning
* => disables kernel preemption
*/
void
pmap_map_ptes(struct pmap *pmap, struct pmap **pmap2, pd_entry_t **ptepp,
pd_entry_t * const **pdeppp)
{
struct pmap *curpmap;
struct cpu_info *ci;
lwp_t *l;
kpreempt_disable();
/* The kernel's pmap is always accessible. */
if (pmap == pmap_kernel()) {
*pmap2 = NULL;
*ptepp = PTE_BASE;
*pdeppp = normal_pdes;
return;
}
KASSERT(mutex_owned(&pmap->pm_lock));
l = curlwp;
ci = l->l_cpu;
curpmap = ci->ci_pmap;
if (pmap == curpmap) {
/*
* Already on the CPU: make it valid. This is very
* often the case during exit(), when we have switched
* to the kernel pmap in order to destroy a user pmap.
*/
if (__predict_false(ci->ci_tlbstate != TLBSTATE_VALID)) {
pmap_reactivate(pmap);
}
*pmap2 = NULL;
} else {
/*
* Toss current pmap from CPU and install new pmap, but keep
* a reference to the old one. Dropping the reference can
* can block as it needs to take locks, so defer that to
* pmap_unmap_ptes().
*/
pmap_reference(pmap);
pmap_load1(l, pmap, curpmap);
*pmap2 = curpmap;
}
KASSERT(ci->ci_tlbstate == TLBSTATE_VALID);
#ifdef DIAGNOSTIC
pmap->pm_ncsw = lwp_pctr();
#endif
*ptepp = PTE_BASE;
#if defined(XENPV) && defined(__x86_64__)
KASSERT(ci->ci_normal_pdes[PTP_LEVELS - 2] == L4_BASE);
ci->ci_normal_pdes[PTP_LEVELS - 2] = pmap->pm_pdir;
*pdeppp = ci->ci_normal_pdes;
#else
*pdeppp = normal_pdes;
#endif
}
/*
* pmap_unmap_ptes: unlock the PTE mapping of "pmap"
*
* => we cannot tolerate context switches while mapped in: assert this.
* => reenables kernel preemption.
* => does not unlock pmap.
*/
void
pmap_unmap_ptes(struct pmap *pmap, struct pmap * pmap2)
{
struct cpu_info *ci;
struct pmap *mypmap;
struct lwp *l;
KASSERT(kpreempt_disabled());
/* The kernel's pmap is always accessible. */
if (pmap == pmap_kernel()) {
kpreempt_enable();
return;
}
l = curlwp;
ci = l->l_cpu;
KASSERT(mutex_owned(&pmap->pm_lock));
KASSERT(pmap->pm_ncsw == lwp_pctr());
#if defined(XENPV) && defined(__x86_64__)
KASSERT(ci->ci_normal_pdes[PTP_LEVELS - 2] != L4_BASE);
ci->ci_normal_pdes[PTP_LEVELS - 2] = L4_BASE;
#endif
/* If not our own pmap, mark whatever's on the CPU now as lazy. */
KASSERT(ci->ci_tlbstate == TLBSTATE_VALID);
mypmap = vm_map_pmap(&l->l_proc->p_vmspace->vm_map);
if (ci->ci_pmap == vm_map_pmap(&l->l_proc->p_vmspace->vm_map)) {
ci->ci_want_pmapload = 0;
} else {
ci->ci_want_pmapload = (mypmap != pmap_kernel());
ci->ci_tlbstate = TLBSTATE_LAZY;
}
/* Now safe to re-enable preemption. */
kpreempt_enable();
/* Toss reference to other pmap taken earlier. */
if (pmap2 != NULL) {
pmap_destroy(pmap2);
}
}
inline static void
pmap_exec_account(struct pmap *pm, vaddr_t va, pt_entry_t opte, pt_entry_t npte)
{
#if !defined(__x86_64__)
if (curproc == NULL || curproc->p_vmspace == NULL ||
pm != vm_map_pmap(&curproc->p_vmspace->vm_map))
return;
if ((opte ^ npte) & PTE_X)
pmap_update_pg(va);
/*
* Executability was removed on the last executable change.
* Reset the code segment to something conservative and
* let the trap handler deal with setting the right limit.
* We can't do that because of locking constraints on the vm map.
*/
if ((opte & PTE_X) && (npte & PTE_X) == 0 && va == pm->pm_hiexec) {
struct trapframe *tf = curlwp->l_md.md_regs;
tf->tf_cs = GSEL(GUCODE_SEL, SEL_UPL);
pm->pm_hiexec = I386_MAX_EXE_ADDR;
}
#endif /* !defined(__x86_64__) */
}
#if !defined(__x86_64__)
/*
* Fixup the code segment to cover all potential executable mappings.
* returns 0 if no changes to the code segment were made.
*/
int
pmap_exec_fixup(struct vm_map *map, struct trapframe *tf, struct pcb *pcb)
{
struct vm_map_entry *ent;
struct pmap *pm = vm_map_pmap(map);
vaddr_t va = 0;
vm_map_lock_read(map);
for (ent = (&map->header)->next; ent != &map->header; ent = ent->next) {
/*
* This entry has greater va than the entries before.
* We need to make it point to the last page, not past it.
*/
if (ent->protection & VM_PROT_EXECUTE)
va = trunc_page(ent->end) - PAGE_SIZE;
}
vm_map_unlock_read(map);
if (va == pm->pm_hiexec && tf->tf_cs == GSEL(GUCODEBIG_SEL, SEL_UPL))
return 0;
pm->pm_hiexec = va;
if (pm->pm_hiexec > I386_MAX_EXE_ADDR) {
tf->tf_cs = GSEL(GUCODEBIG_SEL, SEL_UPL);
} else {
tf->tf_cs = GSEL(GUCODE_SEL, SEL_UPL);
return 0;
}
return 1;
}
#endif /* !defined(__x86_64__) */
void
pat_init(struct cpu_info *ci)
{
#ifndef XENPV
uint64_t pat;
if (!(ci->ci_feat_val[0] & CPUID_PAT))
return;
/* We change WT to WC. Leave all other entries the default values. */
pat = PATENTRY(0, PAT_WB) | PATENTRY(1, PAT_WC) |
PATENTRY(2, PAT_UCMINUS) | PATENTRY(3, PAT_UC) |
PATENTRY(4, PAT_WB) | PATENTRY(5, PAT_WC) |
PATENTRY(6, PAT_UCMINUS) | PATENTRY(7, PAT_UC);
wrmsr(MSR_CR_PAT, pat);
cpu_pat_enabled = true;
#endif
}
static pt_entry_t
pmap_pat_flags(u_int flags)
{
u_int cacheflags = (flags & PMAP_CACHE_MASK);
if (!cpu_pat_enabled) {
switch (cacheflags) {
case PMAP_NOCACHE:
case PMAP_NOCACHE_OVR:
/* results in PGC_UCMINUS on cpus which have
* the cpuid PAT but PAT "disabled"
*/
return PTE_PCD;
default:
return 0;
}
}
switch (cacheflags) {
case PMAP_NOCACHE:
return PGC_UC;
case PMAP_WRITE_COMBINE:
return PGC_WC;
case PMAP_WRITE_BACK:
return PGC_WB;
case PMAP_NOCACHE_OVR:
return PGC_UCMINUS;
}
return 0;
}
/*
* p m a p k e n t e r f u n c t i o n s
*
* functions to quickly enter/remove pages from the kernel address
* space. pmap_kremove is exported to MI kernel. we make use of
* the recursive PTE mappings.
*/
/*
* pmap_kenter_pa: enter a kernel mapping without R/M (pv_entry) tracking
*
* => no need to lock anything, assume va is already allocated
* => should be faster than normal pmap enter function
*/
void
pmap_kenter_pa(vaddr_t va, paddr_t pa, vm_prot_t prot, u_int flags)
{
pt_entry_t *pte, opte, npte;
KASSERT(!(prot & ~VM_PROT_ALL));
if (va < VM_MIN_KERNEL_ADDRESS)
pte = vtopte(va);
else
pte = kvtopte(va);
#if defined(XENPV) && defined(DOM0OPS)
if (pa < pmap_pa_start || pa >= pmap_pa_end) {
#ifdef DEBUG
printf_nolog("%s: pa %#" PRIxPADDR " for va %#" PRIxVADDR
" outside range\n", __func__, pa, va);