FreeBSD/Linux Kernel Cross Reference
sys/i386/include/pmap.h

     /*-
      * 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/8.2/sys/i386/include/pmap.h 217084 2011-01-06 22:57:06Z cperciva $
     */
    
    #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 */
    
    /* Page level cache control fields used to determine the PAT type */
    #define PG_PDE_CACHE    (PG_PDE_PAT | PG_NC_PWT | PG_NC_PCD)
    #define PG_PTE_CACHE    (PG_PTE_PAT | PG_NC_PWT | PG_NC_PCD)
    
    /*
     * 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 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 */
   
   /*
    * Translate a virtual address to the kernel virtual address of its page table
    * entry (PTE).  This can be used recursively.  If the address of a PTE as
    * previously returned by this macro is itself given as the argument, then the
    * address of the page directory entry (PDE) that maps the PTE will be
    * returned.
    *
    * This macro may be used before pmap_bootstrap() is called.
    */
   #define vtopte(va)      (PTmap + i386_btop(va))
   
   /*
    * Translate a virtual address to its physical address.
    *
    * This macro may be used before pmap_bootstrap() is called.
    */
   #define vtophys(va)     pmap_kextract((vm_offset_t)(va))
   
   #ifdef XEN
   #include <sys/param.h>
   #include <machine/xen/xen-os.h>
   #include <machine/xen/xenvar.h>
   #include <machine/xen/xenpmap.h>
   
   extern pt_entry_t pg_nx;
   
   #define PG_KERNEL  (PG_V | PG_A | PG_RW | PG_M)
   
   #define MACH_TO_VM_PAGE(ma) PHYS_TO_VM_PAGE(xpmap_mtop((ma)))
   #define VM_PAGE_TO_MACH(m) xpmap_ptom(VM_PAGE_TO_PHYS((m)))
   
   static __inline vm_paddr_t
   pmap_kextract_ma(vm_offset_t va)
   {
           vm_paddr_t ma;
           if ((ma = PTD[va >> PDRSHIFT]) & PG_PS) {
                   ma = (ma & ~(NBPDR - 1)) | (va & (NBPDR - 1));
           } else {
                   ma = (*vtopte(va) & PG_FRAME) | (va & PAGE_MASK);
           }
           return ma;
   }
   
   static __inline vm_paddr_t
   pmap_kextract(vm_offset_t va)
   {
           return xpmap_mtop(pmap_kextract_ma(va));
   }
   #define vtomach(va)     pmap_kextract_ma(((vm_offset_t) (va)))
   
   vm_paddr_t pmap_extract_ma(struct pmap *pmap, vm_offset_t va);
   
   void    pmap_kenter_ma(vm_offset_t va, vm_paddr_t pa);
   void    pmap_map_readonly(struct pmap *pmap, vm_offset_t va, int len);
   void    pmap_map_readwrite(struct pmap *pmap, vm_offset_t va, int len);
   
   static __inline pt_entry_t
   pte_load_store(pt_entry_t *ptep, pt_entry_t v)
   {
           pt_entry_t r;
   
           r = *ptep;
           PT_SET_VA(ptep, v, TRUE);
           return (r);
   }
   
   static __inline pt_entry_t
   pte_load_store_ma(pt_entry_t *ptep, pt_entry_t v)
   {
           pt_entry_t r;
   
           r = *ptep;
           PT_SET_VA_MA(ptep, v, TRUE);
           return (r);
   }
   
   #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)
   #define pte_store_ma(ptep, pte) pte_load_store_ma((ptep), (pt_entry_t)pte)
   #define pde_store_ma(ptep, pte) pte_load_store_ma((ptep), (pt_entry_t)pte)
   
   #elif !defined(XEN)
   
   /*
    * KPTmap is a linear mapping of the kernel page table.  It differs from the
    * recursive mapping in two ways: (1) it only provides access to kernel page
    * table pages, and not user page table pages, and (2) it provides access to
    * a kernel page table page after the corresponding virtual addresses have
    * been promoted to a 2/4MB page mapping.
    *
    * KPTmap is first initialized by locore to support just NPKT page table
    * pages.  Later, it is reinitialized by pmap_bootstrap() to allow for
    * expansion of the kernel page table.
    */
   extern pt_entry_t *KPTmap;
   
   /*
    * Extract from the kernel page table the physical address that is mapped by
    * the given virtual address "va".
    *
    * This function may be used before pmap_bootstrap() is called.
    */
   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 {
                   /*
                    * Beware of a concurrent promotion that changes the PDE at
                    * this point!  For example, vtopte() must not be used to
                    * access the PTE because it would use the new PDE.  It is,
                    * however, safe to use the old PDE because the page table
                    * page is preserved by the promotion.
                    */
                   pa = KPTmap[i386_btop(va)];
                   pa = (pa & PG_FRAME) | (va & PAGE_MASK);
           }
           return (pa);
   }
   
   #define PT_UPDATES_FLUSH()
   #endif
   
   #if defined(PAE) && !defined(XEN)
   
   #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;
   
   #elif !defined(PAE) && !defined (XEN)
   
   #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)
   {
           __asm volatile("xchgl %0, %1" : "+m" (*ptep), "+r" (pte));
           return (pte);
   }
   
   #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;
           int                     pat_mode;
   };
   
   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 */
           cpumask_t               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
   
   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_page_get_memattr(m)        ((vm_memattr_t)(m)->md.pat_mode)
   #define pmap_unmapbios(va, sz)  pmap_unmapdev((va), (sz))
   
   /*
    * Only the following functions or macros may be used before pmap_bootstrap()
    * is called: pmap_kenter(), pmap_kextract(), pmap_kremove(), vtophys(), and
    * vtopte().
    */
   void    pmap_bootstrap(vm_paddr_t);
   int     pmap_cache_bits(int mode, boolean_t is_pde);
   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_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_page_set_memattr(vm_page_t m, vm_memattr_t ma);
   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);
   void    pmap_invalidate_cache_range(vm_offset_t, vm_offset_t);
   
   #endif /* _KERNEL */
   
   #endif /* !LOCORE */
   
   #endif /* !_MACHINE_PMAP_H_ */

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