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NetBSD/sys/arch/i386/include/pmap.h

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/* $NetBSD: pmap.h,v 1.62 2001/12/23 23:08:41 thorpej Exp $ */
/*
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgment:
* This product includes software developed by Charles D. Cranor and
* Washington University.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 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.
*/
/*
* pmap.h: see pmap.c for the history of this pmap module.
*/
#ifndef _I386_PMAP_H_
#define _I386_PMAP_H_
#if defined(_KERNEL_OPT)
#include "opt_user_ldt.h"
#include "opt_largepages.h"
#endif
#include <machine/cpufunc.h>
#include <machine/pte.h>
#include <machine/segments.h>
#include <uvm/uvm_object.h>
/*
* see pte.h for a description of i386 MMU terminology and hardware
* interface.
*
* a pmap describes a processes' 4GB virtual address space. this
* virtual address space can be broken up into 1024 4MB regions which
* are described by PDEs in the PDP. the PDEs are defined as follows:
*
* (ranges are inclusive -> exclusive, just like vm_map_entry start/end)
* (the following assumes that KERNBASE is 0xc0000000)
*
* PDE#s VA range usage
* 0->767 0x0 -> 0xbfc00000 user address space, note that the
* max user address is 0xbfbfe000
* the final two pages in the last 4MB
* used to be reserved for the UAREA
* but now are no longer used
* 767 0xbfc00000-> recursive mapping of PDP (used for
* 0xc0000000 linear mapping of PTPs)
* 768->1023 0xc0000000-> kernel address space (constant
* 0xffc00000 across all pmap's/processes)
* 1023 0xffc00000-> "alternate" recursive PDP mapping
* <end> (for other pmaps)
*
*
* note: a recursive PDP mapping provides a way to map all the PTEs for
* a 4GB address space into a linear chunk of virtual memory. in other
* words, the PTE for page 0 is the first int mapped into the 4MB recursive
* area. the PTE for page 1 is the second int. the very last int in the
* 4MB range is the PTE that maps VA 0xffffe000 (the last page in a 4GB
* address).
*
* all pmap's PD's must have the same values in slots 768->1023 so that
* the kernel is always mapped in every process. these values are loaded
* into the PD at pmap creation time.
*
* at any one time only one pmap can be active on a processor. this is
* the pmap whose PDP is pointed to by processor register %cr3. this pmap
* will have all its PTEs mapped into memory at the recursive mapping
* point (slot #767 as show above). when the pmap code wants to find the
* PTE for a virtual address, all it has to do is the following:
*
* address of PTE = (767 * 4MB) + (VA / NBPG) * sizeof(pt_entry_t)
* = 0xbfc00000 + (VA / 4096) * 4
*
* what happens if the pmap layer is asked to perform an operation
* on a pmap that is not the one which is currently active? in that
* case we take the PA of the PDP of non-active pmap and put it in
* slot 1023 of the active pmap. this causes the non-active pmap's
* PTEs to get mapped in the final 4MB of the 4GB address space
* (e.g. starting at 0xffc00000).
*
* the following figure shows the effects of the recursive PDP mapping:
*
* PDP (%cr3)
* +----+
* | 0| -> PTP#0 that maps VA 0x0 -> 0x400000
* | |
* | |
* | 767| -> points back to PDP (%cr3) mapping VA 0xbfc00000 -> 0xc0000000
* | 768| -> first kernel PTP (maps 0xc0000000 -> 0xf0400000)
* | |
* |1023| -> points to alternate pmap's PDP (maps 0xffc00000 -> end)
* +----+
*
* note that the PDE#767 VA (0xbfc00000) is defined as "PTE_BASE"
* note that the PDE#1023 VA (0xffc00000) is defined as "APTE_BASE"
*
* starting at VA 0xbfc00000 the current active PDP (%cr3) acts as a
* PTP:
*
* PTP#767 == PDP(%cr3) => maps VA 0xbfc00000 -> 0xc0000000
* +----+
* | 0| -> maps the contents of PTP#0 at VA 0xbfc00000->0xbfc01000
* | |
* | |
* | 767| -> maps contents of PTP#767 (the PDP) at VA 0xbffbf000
* | 768| -> maps contents of first kernel PTP
* | |
* |1023|
* +----+
*
* note that mapping of the PDP at PTP#959's VA (0xeffbf000) is
* defined as "PDP_BASE".... within that mapping there are two
* defines:
* "PDP_PDE" (0xbfeffbfc) is the VA of the PDE in the PDP
* which points back to itself.
* "APDP_PDE" (0xbfeffffc) is the VA of the PDE in the PDP which
* establishes the recursive mapping of the alternate pmap.
* to set the alternate PDP, one just has to put the correct
* PA info in *APDP_PDE.
*
* note that in the APTE_BASE space, the APDP appears at VA
* "APDP_BASE" (0xfffff000).
*/
/*
* the following defines identify the slots used as described above.
*/
#define PDSLOT_PTE ((KERNBASE/NBPD)-1) /* 767: for recursive PDP map */
#define PDSLOT_KERN (KERNBASE/NBPD) /* 768: start of kernel space */
#define PDSLOT_APTE ((unsigned)1023) /* 1023: alternative recursive slot */
/*
* the following defines give the virtual addresses of various MMU
* data structures:
* PTE_BASE and APTE_BASE: the base VA of the linear PTE mappings
* PTD_BASE and APTD_BASE: the base VA of the recursive mapping of the PTD
* PDP_PDE and APDP_PDE: the VA of the PDE that points back to the PDP/APDP
*/
#define PTE_BASE ((pt_entry_t *) (PDSLOT_PTE * NBPD) )
#define APTE_BASE ((pt_entry_t *) (PDSLOT_APTE * NBPD) )
#define PDP_BASE ((pd_entry_t *)(((char *)PTE_BASE) + (PDSLOT_PTE * NBPG)))
#define APDP_BASE ((pd_entry_t *)(((char *)APTE_BASE) + (PDSLOT_APTE * NBPG)))
#define PDP_PDE (PDP_BASE + PDSLOT_PTE)
#define APDP_PDE (PDP_BASE + PDSLOT_APTE)
/*
* the follow define determines how many PTPs should be set up for the
* kernel by locore.s at boot time. this should be large enough to
* get the VM system running. once the VM system is running, the
* pmap module can add more PTPs to the kernel area on demand.
*/
#ifndef NKPTP
#define NKPTP 4 /* 16MB to start */
#endif
#define NKPTP_MIN 4 /* smallest value we allow */
#define NKPTP_MAX (1024 - (KERNBASE/NBPD) - 1)
/* largest value (-1 for APTP space) */
/*
* pdei/ptei: generate index into PDP/PTP from a VA
*/
#define pdei(VA) (((VA) & PD_MASK) >> PDSHIFT)
#define ptei(VA) (((VA) & PT_MASK) >> PGSHIFT)
/*
* PTP macros:
* a PTP's index is the PD index of the PDE that points to it
* a PTP's offset is the byte-offset in the PTE space that this PTP is at
* a PTP's VA is the first VA mapped by that PTP
*
* note that NBPG == number of bytes in a PTP (4096 bytes == 1024 entries)
* NBPD == number of bytes a PTP can map (4MB)
*/
#define ptp_i2o(I) ((I) * NBPG) /* index => offset */
#define ptp_o2i(O) ((O) / NBPG) /* offset => index */
#define ptp_i2v(I) ((I) * NBPD) /* index => VA */
#define ptp_v2i(V) ((V) / NBPD) /* VA => index (same as pdei) */
/*
* PG_AVAIL usage: we make use of the ignored bits of the PTE
*/
#define PG_W PG_AVAIL1 /* "wired" mapping */
#define PG_PVLIST PG_AVAIL2 /* mapping has entry on pvlist */
/* PG_AVAIL3 not used */
#ifdef _KERNEL
/*
* pmap data structures: see pmap.c for details of locking.
*/
struct pmap;
typedef struct pmap *pmap_t;
/*
* we maintain a list of all non-kernel pmaps
*/
LIST_HEAD(pmap_head, pmap); /* struct pmap_head: head of a pmap list */
/*
* the pmap structure
*
* note that the pm_obj contains the simple_lock, the reference count,
* page list, and number of PTPs within the pmap.
*/
struct pmap {
struct uvm_object pm_obj; /* object (lck by object lock) */
#define pm_lock pm_obj.vmobjlock
LIST_ENTRY(pmap) pm_list; /* list (lck by pm_list lock) */
pd_entry_t *pm_pdir; /* VA of PD (lck by object lock) */
u_int32_t pm_pdirpa; /* PA of PD (read-only after create) */
struct vm_page *pm_ptphint; /* pointer to a PTP in our pmap */
struct pmap_statistics pm_stats; /* pmap stats (lck by object lock) */
int pm_flags; /* see below */
union descriptor *pm_ldt; /* user-set LDT */
int pm_ldt_len; /* number of LDT entries */
int pm_ldt_sel; /* LDT selector */
};
/* pm_flags */
#define PMF_USER_LDT 0x01 /* pmap has user-set LDT */
/*
* for each managed physical page we maintain a list of <PMAP,VA>'s
* which it is mapped at. the list is headed by a pv_head structure.
* there is one pv_head per managed phys page (allocated at boot time).
* the pv_head structure points to a list of pv_entry structures (each
* describes one mapping).
*/
struct pv_entry;
struct pv_head {
struct simplelock pvh_lock; /* locks every pv on this list */
struct pv_entry *pvh_list; /* head of list (locked by pvh_lock) */
};
struct pv_entry { /* locked by its list's pvh_lock */
struct pv_entry *pv_next; /* next entry */
struct pmap *pv_pmap; /* the pmap */
vaddr_t pv_va; /* the virtual address */
struct vm_page *pv_ptp; /* the vm_page of the PTP */
};
/*
* pv_entrys are dynamically allocated in chunks from a single page.
* we keep track of how many pv_entrys are in use for each page and
* we can free pv_entry pages if needed. there is one lock for the
* entire allocation system.
*/
struct pv_page_info {
TAILQ_ENTRY(pv_page) pvpi_list;
struct pv_entry *pvpi_pvfree;
int pvpi_nfree;
};
/*
* number of pv_entry's in a pv_page
* (note: won't work on systems where NPBG isn't a constant)
*/
#define PVE_PER_PVPAGE ((NBPG - sizeof(struct pv_page_info)) / \
sizeof(struct pv_entry))
/*
* a pv_page: where pv_entrys are allocated from
*/
struct pv_page {
struct pv_page_info pvinfo;
struct pv_entry pvents[PVE_PER_PVPAGE];
};
/*
* pmap_remove_record: a record of VAs that have been unmapped, used to
* flush TLB. if we have more than PMAP_RR_MAX then we stop recording.
*/
#define PMAP_RR_MAX 16 /* max of 16 pages (64K) */
struct pmap_remove_record {
int prr_npages;
vaddr_t prr_vas[PMAP_RR_MAX];
};
/*
* global kernel variables
*/
/* PTDpaddr: is the physical address of the kernel's PDP */
extern u_long PTDpaddr;
extern struct pmap kernel_pmap_store; /* kernel pmap */
extern int nkpde; /* current # of PDEs for kernel */
extern int pmap_pg_g; /* do we support PG_G? */
/*
* macros
*/
#define pmap_kernel() (&kernel_pmap_store)
#define pmap_resident_count(pmap) ((pmap)->pm_stats.resident_count)
#define pmap_wired_count(pmap) ((pmap)->pm_stats.wired_count)
#define pmap_update(pmap) /* nothing (yet) */
#define pmap_clear_modify(pg) pmap_change_attrs(pg, 0, PG_M)
#define pmap_clear_reference(pg) pmap_change_attrs(pg, 0, PG_U)
#define pmap_copy(DP,SP,D,L,S)
#define pmap_is_modified(pg) pmap_test_attrs(pg, PG_M)
#define pmap_is_referenced(pg) pmap_test_attrs(pg, PG_U)
#define pmap_move(DP,SP,D,L,S)
#define pmap_phys_address(ppn) i386_ptob(ppn)
#define pmap_valid_entry(E) ((E) & PG_V) /* is PDE or PTE valid? */
/*
* prototypes
*/
void pmap_activate __P((struct proc *));
void pmap_bootstrap __P((vaddr_t));
boolean_t pmap_change_attrs __P((struct vm_page *, int, int));
void pmap_deactivate __P((struct proc *));
void pmap_page_remove __P((struct vm_page *));
void pmap_remove __P((struct pmap *, vaddr_t, vaddr_t));
boolean_t pmap_test_attrs __P((struct vm_page *, int));
void pmap_write_protect __P((struct pmap *, vaddr_t,
vaddr_t, vm_prot_t));
vaddr_t reserve_dumppages __P((vaddr_t)); /* XXX: not a pmap fn */
#define PMAP_GROWKERNEL /* turn on pmap_growkernel interface */
/*
* Do idle page zero'ing uncached to avoid polluting the cache.
*/
boolean_t pmap_pageidlezero __P((paddr_t));
#define PMAP_PAGEIDLEZERO(pa) pmap_pageidlezero((pa))
/*
* inline functions
*/
/*
* pmap_update_pg: flush one page from the TLB (or flush the whole thing
* if hardware doesn't support one-page flushing)
*/
__inline static void __attribute__((__unused__))
pmap_update_pg(vaddr_t va)
{
#if defined(I386_CPU)
if (cpu_class == CPUCLASS_386)
tlbflush();
else
#endif
invlpg((u_int) va);
}
/*
* pmap_update_2pg: flush two pages from the TLB
*/
__inline static void __attribute__((__unused__))
pmap_update_2pg(vaddr_t va, vaddr_t vb)
{
#if defined(I386_CPU)
if (cpu_class == CPUCLASS_386)
tlbflush();
else
#endif
{
invlpg((u_int) va);
invlpg((u_int) vb);
}
}
/*
* pmap_page_protect: change the protection of all recorded mappings
* of a managed page
*
* => this function is a frontend for pmap_page_remove/pmap_change_attrs
* => we only have to worry about making the page more protected.
* unprotecting a page is done on-demand at fault time.
*/
__inline static void __attribute__((__unused__))
pmap_page_protect(struct vm_page *pg, vm_prot_t prot)
{
if ((prot & VM_PROT_WRITE) == 0) {
if (prot & (VM_PROT_READ|VM_PROT_EXECUTE)) {
(void) pmap_change_attrs(pg, PG_RO, PG_RW);
} else {
pmap_page_remove(pg);
}
}
}
/*
* pmap_protect: change the protection of pages in a pmap
*
* => this function is a frontend for pmap_remove/pmap_write_protect
* => we only have to worry about making the page more protected.
* unprotecting a page is done on-demand at fault time.
*/
__inline static void __attribute__((__unused__))
pmap_protect(struct pmap *pmap, vaddr_t sva, vaddr_t eva, vm_prot_t prot)
{
if ((prot & VM_PROT_WRITE) == 0) {
if (prot & (VM_PROT_READ|VM_PROT_EXECUTE)) {
pmap_write_protect(pmap, sva, eva, prot);
} else {
pmap_remove(pmap, sva, eva);
}
}
}
/*
* various address inlines
*
* vtopte: return a pointer to the PTE mapping a VA, works only for
* user and PT addresses
*
* kvtopte: return a pointer to the PTE mapping a kernel VA
*/
#include <lib/libkern/libkern.h>
static __inline pt_entry_t * __attribute__((__unused__))
vtopte(vaddr_t va)
{
KASSERT(va < (PDSLOT_KERN << PDSHIFT));
return (PTE_BASE + i386_btop(va));
}
static __inline pt_entry_t * __attribute__((__unused__))
kvtopte(vaddr_t va)
{
KASSERT(va >= (PDSLOT_KERN << PDSHIFT));
#ifdef LARGEPAGES
{
pd_entry_t *pde;
pde = PDP_BASE + pdei(va);
if (*pde & PG_PS)
return ((pt_entry_t *)pde);
}
#endif
return (PTE_BASE + i386_btop(va));
}
paddr_t vtophys __P((vaddr_t));
vaddr_t pmap_map __P((vaddr_t, paddr_t, paddr_t, vm_prot_t));
#if defined(USER_LDT)
void pmap_ldt_cleanup __P((struct proc *));
#define PMAP_FORK
#endif /* USER_LDT */
#endif /* _KERNEL */
#endif /* _I386_PMAP_H_ */
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