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freebsd-dev/sys/i386/include/pmap.h
Alan Cox 97dbe5e48e MFamd64 with few changes: 
1. Add support for automatic promotion of 4KB page mappings to 2MB page
   mappings.  Automatic promotion can be enabled by setting the tunable
   "vm.pmap.pg_ps_enabled" to a non-zero value.  By default, automatic
   promotion is disabled.  Tested by: kris

2. To date, we have assumed that the TLB will only set the PG_M bit in a
   PTE if that PTE has the PG_RW bit set.  However, this assumption does
   not hold on recent processors from Intel.  For example, consider a PTE
   that has the PG_RW bit set but the PG_M bit clear.  Suppose this PTE
   is cached in the TLB and later the PG_RW bit is cleared in the PTE,
   but the corresponding TLB entry is not (yet) invalidated.
   Historically, upon a write access using this (stale) TLB entry, the
   TLB would observe that the PG_RW bit had been cleared and initiate a
   page fault, aborting the setting of the PG_M bit in the PTE.  Now,
   however, P4- and Core2-family processors will set the PG_M bit before
   observing that the PG_RW bit is clear and initiating a page fault.  In
   other words, the write does not occur but the PG_M bit is still set.

   The real impact of this difference is not that great.  Specifically,
   we should no longer assert that any PTE with the PG_M bit set must
   also have the PG_RW bit set, and we should ignore the state of the
   PG_M bit unless the PG_RW bit is set.
2008-03-27 04:34:17 +00:00

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/*-
* Copyright (c) 1991 Regents of the University of California.
* 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 of UUNET Technologies 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.
* 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.
*
* Derived from hp300 version by Mike Hibler, this version by William
* Jolitz uses a recursive map [a pde points to the page directory] to
* map the page tables using the pagetables themselves. This is done to
* reduce the impact on kernel virtual memory for lots of sparse address
* space, and to reduce the cost of memory to each process.
*
* from: hp300: @(#)pmap.h 7.2 (Berkeley) 12/16/90
* from: @(#)pmap.h 7.4 (Berkeley) 5/12/91
* $FreeBSD$
*/
#ifndef _MACHINE_PMAP_H_
#define _MACHINE_PMAP_H_
/*
* Page-directory and page-table entries follow this format, with a few
* of the fields not present here and there, depending on a lot of things.
*/
/* ---- Intel Nomenclature ---- */
#define PG_V 0x001 /* P Valid */
#define PG_RW 0x002 /* R/W Read/Write */
#define PG_U 0x004 /* U/S User/Supervisor */
#define PG_NC_PWT 0x008 /* PWT Write through */
#define PG_NC_PCD 0x010 /* PCD Cache disable */
#define PG_A 0x020 /* A Accessed */
#define PG_M 0x040 /* D Dirty */
#define PG_PS 0x080 /* PS Page size (0=4k,1=4M) */
#define PG_PTE_PAT 0x080 /* PAT PAT index */
#define PG_G 0x100 /* G Global */
#define PG_AVAIL1 0x200 /* / Available for system */
#define PG_AVAIL2 0x400 /* < programmers use */
#define PG_AVAIL3 0x800 /* \ */
#define PG_PDE_PAT 0x1000 /* PAT PAT index */
#ifdef PAE
#define PG_NX (1ull<<63) /* No-execute */
#endif
/* Our various interpretations of the above */
#define PG_W PG_AVAIL1 /* "Wired" pseudoflag */
#define PG_MANAGED PG_AVAIL2
#ifdef PAE
#define PG_FRAME (0x000ffffffffff000ull)
#define PG_PS_FRAME (0x000fffffffe00000ull)
#else
#define PG_FRAME (~PAGE_MASK)
#define PG_PS_FRAME (0xffc00000)
#endif
#define PG_PROT (PG_RW|PG_U) /* all protection bits . */
#define PG_N (PG_NC_PWT|PG_NC_PCD) /* Non-cacheable */
/*
* Promotion to a 2 or 4MB (PDE) page mapping requires that the corresponding
* 4KB (PTE) page mappings have identical settings for the following fields:
*/
#define PG_PTE_PROMOTE (PG_MANAGED | PG_W | PG_G | PG_PTE_PAT | \
PG_M | PG_A | PG_NC_PCD | PG_NC_PWT | PG_U | PG_RW | PG_V)
/*
* Page Protection Exception bits
*/
#define PGEX_P 0x01 /* Protection violation vs. not present */
#define PGEX_W 0x02 /* during a Write cycle */
#define PGEX_U 0x04 /* access from User mode (UPL) */
#define PGEX_RSV 0x08 /* reserved PTE field is non-zero */
#define PGEX_I 0x10 /* during an instruction fetch */
/*
* Size of Kernel address space. This is the number of page table pages
* (4MB each) to use for the kernel. 256 pages == 1 Gigabyte.
* This **MUST** be a multiple of 4 (eg: 252, 256, 260, etc).
* For PAE, the page table page unit size is 2MB. This means that 512 pages
* is 1 Gigabyte. Double everything. It must be a multiple of 8 for PAE.
*/
#ifndef KVA_PAGES
#ifdef PAE
#define KVA_PAGES 512
#else
#define KVA_PAGES 256
#endif
#endif
/*
* Pte related macros
*/
#define VADDR(pdi, pti) ((vm_offset_t)(((pdi)<<PDRSHIFT)|((pti)<<PAGE_SHIFT)))
/* Initial number of kernel page tables. */
#ifndef NKPT
#ifdef PAE
/* 152 page tables needed to map 16G (76B "struct vm_page", 2M page tables). */
#define NKPT 240
#else
/* 18 page tables needed to map 4G (72B "struct vm_page", 4M page tables). */
#define NKPT 30
#endif
#endif
#ifndef NKPDE
#define NKPDE (KVA_PAGES) /* number of page tables/pde's */
#endif
/*
* The *PTDI values control the layout of virtual memory
*
* XXX This works for now, but I am not real happy with it, I'll fix it
* right after I fix locore.s and the magic 28K hole
*/
#define KPTDI (NPDEPTD-NKPDE) /* start of kernel virtual pde's */
#define PTDPTDI (KPTDI-NPGPTD) /* ptd entry that points to ptd! */
/*
* XXX doesn't really belong here I guess...
*/
#define ISA_HOLE_START 0xa0000
#define ISA_HOLE_LENGTH (0x100000-ISA_HOLE_START)
#ifndef LOCORE
#include <sys/queue.h>
#include <sys/_lock.h>
#include <sys/_mutex.h>
#ifdef PAE
typedef uint64_t pdpt_entry_t;
typedef uint64_t pd_entry_t;
typedef uint64_t pt_entry_t;
#define PTESHIFT (3)
#define PDESHIFT (3)
#else
typedef uint32_t pd_entry_t;
typedef uint32_t pt_entry_t;
#define PTESHIFT (2)
#define PDESHIFT (2)
#endif
/*
* Address of current and alternate address space page table maps
* and directories.
*/
#ifdef _KERNEL
extern pt_entry_t PTmap[];
extern pd_entry_t PTD[];
extern pd_entry_t PTDpde[];
#ifdef PAE
extern pdpt_entry_t *IdlePDPT;
#endif
extern pd_entry_t *IdlePTD; /* physical address of "Idle" state directory */
#endif
#ifdef _KERNEL
/*
* virtual address to page table entry and
* to physical address.
* Note: these work recursively, thus vtopte of a pte will give
* the corresponding pde that in turn maps it.
*/
#define vtopte(va) (PTmap + i386_btop(va))
#define vtophys(va) pmap_kextract((vm_offset_t)(va))
/*
* Routine: pmap_kextract
* Function:
* Extract the physical page address associated
* kernel virtual address.
*/
static __inline vm_paddr_t
pmap_kextract(vm_offset_t va)
{
vm_paddr_t pa;
if ((pa = PTD[va >> PDRSHIFT]) & PG_PS) {
pa = (pa & PG_PS_FRAME) | (va & PDRMASK);
} else {
pa = *vtopte(va);
pa = (pa & PG_FRAME) | (va & PAGE_MASK);
}
return pa;
}
#ifdef PAE
#define pde_cmpset(pdep, old, new) \
atomic_cmpset_64((pdep), (old), (new))
static __inline pt_entry_t
pte_load(pt_entry_t *ptep)
{
pt_entry_t r;
__asm __volatile(
"lock; cmpxchg8b %1"
: "=A" (r)
: "m" (*ptep), "a" (0), "d" (0), "b" (0), "c" (0));
return (r);
}
static __inline pt_entry_t
pte_load_store(pt_entry_t *ptep, pt_entry_t v)
{
pt_entry_t r;
r = *ptep;
__asm __volatile(
"1:\n"
"\tlock; cmpxchg8b %1\n"
"\tjnz 1b"
: "+A" (r)
: "m" (*ptep), "b" ((uint32_t)v), "c" ((uint32_t)(v >> 32)));
return (r);
}
/* XXXRU move to atomic.h? */
static __inline int
atomic_cmpset_64(volatile uint64_t *dst, uint64_t exp, uint64_t src)
{
int64_t res = exp;
__asm __volatile (
" lock ; "
" cmpxchg8b %2 ; "
" setz %%al ; "
" movzbl %%al,%0 ; "
"# atomic_cmpset_64"
: "+A" (res), /* 0 (result) */
"=m" (*dst) /* 1 */
: "m" (*dst), /* 2 */
"b" ((uint32_t)src),
"c" ((uint32_t)(src >> 32)));
return (res);
}
#define pte_load_clear(ptep) pte_load_store((ptep), (pt_entry_t)0ULL)
#define pte_store(ptep, pte) pte_load_store((ptep), (pt_entry_t)pte)
extern pt_entry_t pg_nx;
#else /* PAE */
#define pde_cmpset(pdep, old, new) \
atomic_cmpset_int((pdep), (old), (new))
static __inline pt_entry_t
pte_load(pt_entry_t *ptep)
{
pt_entry_t r;
r = *ptep;
return (r);
}
static __inline pt_entry_t
pte_load_store(pt_entry_t *ptep, pt_entry_t pte)
{
pt_entry_t r;
__asm __volatile(
"xchgl %0,%1"
: "=m" (*ptep),
"=r" (r)
: "1" (pte),
"m" (*ptep));
return (r);
}
#define pte_load_clear(pte) atomic_readandclear_int(pte)
static __inline void
pte_store(pt_entry_t *ptep, pt_entry_t pte)
{
*ptep = pte;
}
#endif /* PAE */
#define pte_clear(ptep) pte_store((ptep), (pt_entry_t)0ULL)
#define pde_store(pdep, pde) pte_store((pdep), (pde))
#endif /* _KERNEL */
/*
* Pmap stuff
*/
struct pv_entry;
struct pv_chunk;
struct md_page {
TAILQ_HEAD(,pv_entry) pv_list;
};
struct pmap {
struct mtx pm_mtx;
pd_entry_t *pm_pdir; /* KVA of page directory */
TAILQ_HEAD(,pv_chunk) pm_pvchunk; /* list of mappings in pmap */
u_int pm_active; /* active on cpus */
struct pmap_statistics pm_stats; /* pmap statistics */
LIST_ENTRY(pmap) pm_list; /* List of all pmaps */
#ifdef PAE
pdpt_entry_t *pm_pdpt; /* KVA of page director pointer
table */
#endif
vm_page_t pm_root; /* spare page table pages */
};
typedef struct pmap *pmap_t;
#ifdef _KERNEL
extern struct pmap kernel_pmap_store;
#define kernel_pmap (&kernel_pmap_store)
#define PMAP_LOCK(pmap) mtx_lock(&(pmap)->pm_mtx)
#define PMAP_LOCK_ASSERT(pmap, type) \
mtx_assert(&(pmap)->pm_mtx, (type))
#define PMAP_LOCK_DESTROY(pmap) mtx_destroy(&(pmap)->pm_mtx)
#define PMAP_LOCK_INIT(pmap) mtx_init(&(pmap)->pm_mtx, "pmap", \
NULL, MTX_DEF | MTX_DUPOK)
#define PMAP_LOCKED(pmap) mtx_owned(&(pmap)->pm_mtx)
#define PMAP_MTX(pmap) (&(pmap)->pm_mtx)
#define PMAP_TRYLOCK(pmap) mtx_trylock(&(pmap)->pm_mtx)
#define PMAP_UNLOCK(pmap) mtx_unlock(&(pmap)->pm_mtx)
#endif
/*
* For each vm_page_t, there is a list of all currently valid virtual
* mappings of that page. An entry is a pv_entry_t, the list is pv_list.
*/
typedef struct pv_entry {
vm_offset_t pv_va; /* virtual address for mapping */
TAILQ_ENTRY(pv_entry) pv_list;
} *pv_entry_t;
/*
* pv_entries are allocated in chunks per-process. This avoids the
* need to track per-pmap assignments.
*/
#define _NPCM 11
#define _NPCPV 336
struct pv_chunk {
pmap_t pc_pmap;
TAILQ_ENTRY(pv_chunk) pc_list;
uint32_t pc_map[_NPCM]; /* bitmap; 1 = free */
uint32_t pc_spare[2];
struct pv_entry pc_pventry[_NPCPV];
};
#ifdef _KERNEL
#define NPPROVMTRR 8
#define PPRO_VMTRRphysBase0 0x200
#define PPRO_VMTRRphysMask0 0x201
struct ppro_vmtrr {
u_int64_t base, mask;
};
extern struct ppro_vmtrr PPro_vmtrr[NPPROVMTRR];
extern caddr_t CADDR1;
extern pt_entry_t *CMAP1;
extern vm_paddr_t phys_avail[];
extern vm_paddr_t dump_avail[];
extern int pseflag;
extern int pgeflag;
extern char *ptvmmap; /* poor name! */
extern vm_offset_t virtual_avail;
extern vm_offset_t virtual_end;
#define pmap_unmapbios(va, sz) pmap_unmapdev((va), (sz))
void pmap_bootstrap(vm_paddr_t);
int pmap_change_attr(vm_offset_t, vm_size_t, int);
void pmap_init_pat(void);
void pmap_kenter(vm_offset_t va, vm_paddr_t pa);
void pmap_kenter_attr(vm_offset_t va, vm_paddr_t pa, int mode);
void *pmap_kenter_temporary(vm_paddr_t pa, int i);
void pmap_kremove(vm_offset_t);
void *pmap_mapbios(vm_paddr_t, vm_size_t);
void *pmap_mapdev(vm_paddr_t, vm_size_t);
void *pmap_mapdev_attr(vm_paddr_t, vm_size_t, int);
boolean_t pmap_page_is_mapped(vm_page_t m);
void pmap_unmapdev(vm_offset_t, vm_size_t);
pt_entry_t *pmap_pte(pmap_t, vm_offset_t) __pure2;
void pmap_set_pg(void);
void pmap_invalidate_page(pmap_t, vm_offset_t);
void pmap_invalidate_range(pmap_t, vm_offset_t, vm_offset_t);
void pmap_invalidate_all(pmap_t);
void pmap_invalidate_cache(void);
#endif /* _KERNEL */
#endif /* !LOCORE */
#endif /* !_MACHINE_PMAP_H_ */
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