FreeBSD/Linux Kernel Cross Reference
sys/amd64/include/pmap.h

     /*-
      * Copyright (c) 2003 Peter Wemm.
      * 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: releng/11.0/sys/amd64/include/pmap.h 299350 2016-05-10 09:58:51Z kib $
     */
    
    #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 X86_PG_V        0x001   /* P    Valid                   */
    #define X86_PG_RW       0x002   /* R/W  Read/Write              */
    #define X86_PG_U        0x004   /* U/S  User/Supervisor         */
    #define X86_PG_NC_PWT   0x008   /* PWT  Write through           */
    #define X86_PG_NC_PCD   0x010   /* PCD  Cache disable           */
    #define X86_PG_A        0x020   /* A    Accessed                */
    #define X86_PG_M        0x040   /* D    Dirty                   */
    #define X86_PG_PS       0x080   /* PS   Page size (0=4k,1=2M)   */
    #define X86_PG_PTE_PAT  0x080   /* PAT  PAT index               */
    #define X86_PG_G        0x100   /* G    Global                  */
    #define X86_PG_AVAIL1   0x200   /*    / Available for system    */
    #define X86_PG_AVAIL2   0x400   /*   <  programmers use         */
    #define X86_PG_AVAIL3   0x800   /*    \                         */
    #define X86_PG_PDE_PAT  0x1000  /* PAT  PAT index               */
    #define X86_PG_NX       (1ul<<63) /* No-execute */
    #define X86_PG_AVAIL(x) (1ul << (x))
    
    /* Page level cache control fields used to determine the PAT type */
    #define X86_PG_PDE_CACHE (X86_PG_PDE_PAT | X86_PG_NC_PWT | X86_PG_NC_PCD)
    #define X86_PG_PTE_CACHE (X86_PG_PTE_PAT | X86_PG_NC_PWT | X86_PG_NC_PCD)
    
    /*
     * Intel extended page table (EPT) bit definitions.
     */
    #define EPT_PG_READ             0x001   /* R    Read            */
    #define EPT_PG_WRITE            0x002   /* W    Write           */
    #define EPT_PG_EXECUTE          0x004   /* X    Execute         */
    #define EPT_PG_IGNORE_PAT       0x040   /* IPAT Ignore PAT      */
    #define EPT_PG_PS               0x080   /* PS   Page size       */
    #define EPT_PG_A                0x100   /* A    Accessed        */
    #define EPT_PG_M                0x200   /* D    Dirty           */
    #define EPT_PG_MEMORY_TYPE(x)   ((x) << 3) /* MT Memory Type    */
    
    /*
     * Define the PG_xx macros in terms of the bits on x86 PTEs.
     */
    #define PG_V            X86_PG_V
    #define PG_RW           X86_PG_RW
    #define PG_U            X86_PG_U
    #define PG_NC_PWT       X86_PG_NC_PWT
    #define PG_NC_PCD       X86_PG_NC_PCD
    #define PG_A            X86_PG_A
    #define PG_M            X86_PG_M
    #define PG_PS           X86_PG_PS
    #define PG_PTE_PAT      X86_PG_PTE_PAT
    #define PG_G            X86_PG_G
    #define PG_AVAIL1       X86_PG_AVAIL1
   #define PG_AVAIL2       X86_PG_AVAIL2
   #define PG_AVAIL3       X86_PG_AVAIL3
   #define PG_PDE_PAT      X86_PG_PDE_PAT
   #define PG_NX           X86_PG_NX
   #define PG_PDE_CACHE    X86_PG_PDE_CACHE
   #define PG_PTE_CACHE    X86_PG_PTE_CACHE
   
   /* Our various interpretations of the above */
   #define PG_W            X86_PG_AVAIL3   /* "Wired" pseudoflag */
   #define PG_MANAGED      X86_PG_AVAIL2
   #define EPT_PG_EMUL_V   X86_PG_AVAIL(52)
   #define EPT_PG_EMUL_RW  X86_PG_AVAIL(53)
   #define PG_FRAME        (0x000ffffffffff000ul)
   #define PG_PS_FRAME     (0x000fffffffe00000ul)
   
   /*
    * Promotion to a 2MB (PDE) page mapping requires that the corresponding 4KB
    * (PTE) page mappings have identical settings for the following fields:
    */
   #define PG_PTE_PROMOTE  (PG_NX | PG_MANAGED | PG_W | PG_G | PG_PTE_CACHE | \
               PG_M | PG_A | 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 */
   
   /* 
    * undef the PG_xx macros that define bits in the regular x86 PTEs that
    * have a different position in nested PTEs. This is done when compiling
    * code that needs to be aware of the differences between regular x86 and
    * nested PTEs.
    *
    * The appropriate bitmask will be calculated at runtime based on the pmap
    * type.
    */
   #ifdef AMD64_NPT_AWARE
   #undef PG_AVAIL1                /* X86_PG_AVAIL1 aliases with EPT_PG_M */
   #undef PG_G
   #undef PG_A
   #undef PG_M
   #undef PG_PDE_PAT
   #undef PG_PDE_CACHE
   #undef PG_PTE_PAT
   #undef PG_PTE_CACHE
   #undef PG_RW
   #undef PG_V
   #endif
   
   /*
    * Pte related macros.  This is complicated by having to deal with
    * the sign extension of the 48th bit.
    */
   #define KVADDR(l4, l3, l2, l1) ( \
           ((unsigned long)-1 << 47) | \
           ((unsigned long)(l4) << PML4SHIFT) | \
           ((unsigned long)(l3) << PDPSHIFT) | \
           ((unsigned long)(l2) << PDRSHIFT) | \
           ((unsigned long)(l1) << PAGE_SHIFT))
   
   #define UVADDR(l4, l3, l2, l1) ( \
           ((unsigned long)(l4) << PML4SHIFT) | \
           ((unsigned long)(l3) << PDPSHIFT) | \
           ((unsigned long)(l2) << PDRSHIFT) | \
           ((unsigned long)(l1) << PAGE_SHIFT))
   
   /*
    * Number of kernel PML4 slots.  Can be anywhere from 1 to 64 or so,
    * but setting it larger than NDMPML4E makes no sense.
    *
    * Each slot provides .5 TB of kernel virtual space.
    */
   #define NKPML4E         4
   
   #define NUPML4E         (NPML4EPG/2)    /* number of userland PML4 pages */
   #define NUPDPE          (NUPML4E*NPDPEPG)/* number of userland PDP pages */
   #define NUPDE           (NUPDPE*NPDEPG) /* number of userland PD entries */
   
   /*
    * NDMPML4E is the maximum number of PML4 entries that will be
    * used to implement the direct map.  It must be a power of two,
    * and should generally exceed NKPML4E.  The maximum possible
    * value is 64; using 128 will make the direct map intrude into
    * the recursive page table map.
    */
   #define NDMPML4E        8
   
   /*
    * These values control the layout of virtual memory.  The starting address
    * of the direct map, which is controlled by DMPML4I, must be a multiple of
    * its size.  (See the PHYS_TO_DMAP() and DMAP_TO_PHYS() macros.)
    *
    * Note: KPML4I is the index of the (single) level 4 page that maps
    * the KVA that holds KERNBASE, while KPML4BASE is the index of the
    * first level 4 page that maps VM_MIN_KERNEL_ADDRESS.  If NKPML4E
    * is 1, these are the same, otherwise KPML4BASE < KPML4I and extra
    * level 4 PDEs are needed to map from VM_MIN_KERNEL_ADDRESS up to
    * KERNBASE.
    *
    * (KPML4I combines with KPDPI to choose where KERNBASE starts.
    * Or, in other words, KPML4I provides bits 39..47 of KERNBASE,
    * and KPDPI provides bits 30..38.)
    */
   #define PML4PML4I       (NPML4EPG/2)    /* Index of recursive pml4 mapping */
   
   #define KPML4BASE       (NPML4EPG-NKPML4E) /* KVM at highest addresses */
   #define DMPML4I         rounddown(KPML4BASE-NDMPML4E, NDMPML4E) /* Below KVM */
   
   #define KPML4I          (NPML4EPG-1)
   #define KPDPI           (NPDPEPG-2)     /* kernbase at -2GB */
   
   /*
    * XXX doesn't really belong here I guess...
    */
   #define ISA_HOLE_START    0xa0000
   #define ISA_HOLE_LENGTH (0x100000-ISA_HOLE_START)
   
   #define PMAP_PCID_NONE          0xffffffff
   #define PMAP_PCID_KERN          0
   #define PMAP_PCID_OVERMAX       0x1000
   
   #ifndef LOCORE
   
   #include <sys/queue.h>
   #include <sys/_cpuset.h>
   #include <sys/_lock.h>
   #include <sys/_mutex.h>
   
   #include <vm/_vm_radix.h>
   
   typedef u_int64_t pd_entry_t;
   typedef u_int64_t pt_entry_t;
   typedef u_int64_t pdp_entry_t;
   typedef u_int64_t pml4_entry_t;
   
   /*
    * Address of current address space page table maps and directories.
    */
   #ifdef _KERNEL
   #define addr_PTmap      (KVADDR(PML4PML4I, 0, 0, 0))
   #define addr_PDmap      (KVADDR(PML4PML4I, PML4PML4I, 0, 0))
   #define addr_PDPmap     (KVADDR(PML4PML4I, PML4PML4I, PML4PML4I, 0))
   #define addr_PML4map    (KVADDR(PML4PML4I, PML4PML4I, PML4PML4I, PML4PML4I))
   #define addr_PML4pml4e  (addr_PML4map + (PML4PML4I * sizeof(pml4_entry_t)))
   #define PTmap           ((pt_entry_t *)(addr_PTmap))
   #define PDmap           ((pd_entry_t *)(addr_PDmap))
   #define PDPmap          ((pd_entry_t *)(addr_PDPmap))
   #define PML4map         ((pd_entry_t *)(addr_PML4map))
   #define PML4pml4e       ((pd_entry_t *)(addr_PML4pml4e))
   
   extern int nkpt;                /* Initial number of kernel page tables */
   extern u_int64_t KPDPphys;      /* physical address of kernel level 3 */
   extern u_int64_t KPML4phys;     /* physical address of kernel level 4 */
   
   /*
    * 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.
    */
   pt_entry_t *vtopte(vm_offset_t);
   #define vtophys(va)     pmap_kextract(((vm_offset_t) (va)))
   
   #define pte_load_store(ptep, pte)       atomic_swap_long(ptep, pte)
   #define pte_load_clear(ptep)            atomic_swap_long(ptep, 0)
   #define pte_store(ptep, pte) do { \
           *(u_long *)(ptep) = (u_long)(pte); \
   } while (0)
   #define pte_clear(ptep)                 pte_store(ptep, 0)
   
   #define pde_store(pdep, pde)            pte_store(pdep, pde)
   
   extern pt_entry_t pg_nx;
   
   #endif /* _KERNEL */
   
   /*
    * Pmap stuff
    */
   struct  pv_entry;
   struct  pv_chunk;
   
   /*
    * Locks
    * (p) PV list lock
    */
   struct md_page {
           TAILQ_HEAD(, pv_entry)  pv_list;  /* (p) */
           int                     pv_gen;   /* (p) */
           int                     pat_mode;
   };
   
   enum pmap_type {
           PT_X86,                 /* regular x86 page tables */
           PT_EPT,                 /* Intel's nested page tables */
           PT_RVI,                 /* AMD's nested page tables */
   };
   
   struct pmap_pcids {
           uint32_t        pm_pcid;
           uint32_t        pm_gen;
   };
   
   /*
    * The kernel virtual address (KVA) of the level 4 page table page is always
    * within the direct map (DMAP) region.
    */
   struct pmap {
           struct mtx              pm_mtx;
           pml4_entry_t            *pm_pml4;       /* KVA of level 4 page table */
           uint64_t                pm_cr3;
           TAILQ_HEAD(,pv_chunk)   pm_pvchunk;     /* list of mappings in pmap */
           cpuset_t                pm_active;      /* active on cpus */
           enum pmap_type          pm_type;        /* regular or nested tables */
           struct pmap_statistics  pm_stats;       /* pmap statistics */
           struct vm_radix         pm_root;        /* spare page table pages */
           long                    pm_eptgen;      /* EPT pmap generation id */
           int                     pm_flags;
           struct pmap_pcids       pm_pcids[MAXCPU];
   };
   
   /* flags */
   #define PMAP_NESTED_IPIMASK     0xff
   #define PMAP_PDE_SUPERPAGE      (1 << 8)        /* supports 2MB superpages */
   #define PMAP_EMULATE_AD_BITS    (1 << 9)        /* needs A/D bits emulation */
   #define PMAP_SUPPORTS_EXEC_ONLY (1 << 10)       /* execute only mappings ok */
   
   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)
   
   int     pmap_pinit_type(pmap_t pmap, enum pmap_type pm_type, int flags);
   int     pmap_emulate_accessed_dirty(pmap_t pmap, vm_offset_t va, int ftype);
   #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_next;
   } *pv_entry_t;
   
   /*
    * pv_entries are allocated in chunks per-process.  This avoids the
    * need to track per-pmap assignments.
    */
   #define _NPCM   3
   #define _NPCPV  168
   struct pv_chunk {
           pmap_t                  pc_pmap;
           TAILQ_ENTRY(pv_chunk)   pc_list;
           uint64_t                pc_map[_NPCM];  /* bitmap; 1 = free */
           TAILQ_ENTRY(pv_chunk)   pc_lru;
           struct pv_entry         pc_pventry[_NPCPV];
   };
   
   #ifdef  _KERNEL
   
   extern caddr_t  CADDR1;
   extern pt_entry_t *CMAP1;
   extern vm_paddr_t phys_avail[];
   extern vm_paddr_t dump_avail[];
   extern vm_offset_t virtual_avail;
   extern vm_offset_t virtual_end;
   extern vm_paddr_t dmaplimit;
   
   #define pmap_page_get_memattr(m)        ((vm_memattr_t)(m)->md.pat_mode)
   #define pmap_page_is_write_mapped(m)    (((m)->aflags & PGA_WRITEABLE) != 0)
   #define pmap_unmapbios(va, sz)  pmap_unmapdev((va), (sz))
   
   struct thread;
   
   void    pmap_activate_sw(struct thread *);
   void    pmap_bootstrap(vm_paddr_t *);
   int     pmap_change_attr(vm_offset_t, vm_size_t, int);
   void    pmap_demote_DMAP(vm_paddr_t base, vm_size_t len, boolean_t invalidate);
   void    pmap_init_pat(void);
   void    pmap_kenter(vm_offset_t va, vm_paddr_t pa);
   void    *pmap_kenter_temporary(vm_paddr_t pa, int i);
   vm_paddr_t pmap_kextract(vm_offset_t);
   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_page_set_memattr(vm_page_t m, vm_memattr_t ma);
   void    pmap_unmapdev(vm_offset_t, vm_size_t);
   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);
   void    pmap_invalidate_cache_pages(vm_page_t *pages, int count);
   void    pmap_invalidate_cache_range(vm_offset_t sva, vm_offset_t eva,
               boolean_t force);
   void    pmap_get_mapping(pmap_t pmap, vm_offset_t va, uint64_t *ptr, int *num);
   boolean_t pmap_map_io_transient(vm_page_t *, vm_offset_t *, int, boolean_t);
   void    pmap_unmap_io_transient(vm_page_t *, vm_offset_t *, int, boolean_t);
   #endif /* _KERNEL */
   
   #endif /* !LOCORE */
   
   #endif /* !_MACHINE_PMAP_H_ */

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