The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/i386/include/pmap.h

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    1 /*-
    2  * Copyright (c) 1991 Regents of the University of California.
    3  * All rights reserved.
    4  *
    5  * This code is derived from software contributed to Berkeley by
    6  * the Systems Programming Group of the University of Utah Computer
    7  * Science Department and William Jolitz of UUNET Technologies Inc.
    8  *
    9  * Redistribution and use in source and binary forms, with or without
   10  * modification, are permitted provided that the following conditions
   11  * are met:
   12  * 1. Redistributions of source code must retain the above copyright
   13  *    notice, this list of conditions and the following disclaimer.
   14  * 2. Redistributions in binary form must reproduce the above copyright
   15  *    notice, this list of conditions and the following disclaimer in the
   16  *    documentation and/or other materials provided with the distribution.
   17  * 4. Neither the name of the University nor the names of its contributors
   18  *    may be used to endorse or promote products derived from this software
   19  *    without specific prior written permission.
   20  *
   21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   31  * SUCH DAMAGE.
   32  *
   33  * Derived from hp300 version by Mike Hibler, this version by William
   34  * Jolitz uses a recursive map [a pde points to the page directory] to
   35  * map the page tables using the pagetables themselves. This is done to
   36  * reduce the impact on kernel virtual memory for lots of sparse address
   37  * space, and to reduce the cost of memory to each process.
   38  *
   39  *      from: hp300: @(#)pmap.h 7.2 (Berkeley) 12/16/90
   40  *      from: @(#)pmap.h        7.4 (Berkeley) 5/12/91
   41  * $FreeBSD: stable/9/sys/i386/include/pmap.h 267964 2014-06-27 17:22:18Z jhb $
   42  */
   43 
   44 #ifndef _MACHINE_PMAP_H_
   45 #define _MACHINE_PMAP_H_
   46 
   47 /*
   48  * Page-directory and page-table entries follow this format, with a few
   49  * of the fields not present here and there, depending on a lot of things.
   50  */
   51                                 /* ---- Intel Nomenclature ---- */
   52 #define PG_V            0x001   /* P    Valid                   */
   53 #define PG_RW           0x002   /* R/W  Read/Write              */
   54 #define PG_U            0x004   /* U/S  User/Supervisor         */
   55 #define PG_NC_PWT       0x008   /* PWT  Write through           */
   56 #define PG_NC_PCD       0x010   /* PCD  Cache disable           */
   57 #define PG_A            0x020   /* A    Accessed                */
   58 #define PG_M            0x040   /* D    Dirty                   */
   59 #define PG_PS           0x080   /* PS   Page size (0=4k,1=4M)   */
   60 #define PG_PTE_PAT      0x080   /* PAT  PAT index               */
   61 #define PG_G            0x100   /* G    Global                  */
   62 #define PG_AVAIL1       0x200   /*    / Available for system    */
   63 #define PG_AVAIL2       0x400   /*   <  programmers use         */
   64 #define PG_AVAIL3       0x800   /*    \                         */
   65 #define PG_PDE_PAT      0x1000  /* PAT  PAT index               */
   66 #ifdef PAE
   67 #define PG_NX           (1ull<<63) /* No-execute */
   68 #endif
   69 
   70 
   71 /* Our various interpretations of the above */
   72 #define PG_W            PG_AVAIL1       /* "Wired" pseudoflag */
   73 #define PG_MANAGED      PG_AVAIL2
   74 #ifdef PAE
   75 #define PG_FRAME        (0x000ffffffffff000ull)
   76 #define PG_PS_FRAME     (0x000fffffffe00000ull)
   77 #else
   78 #define PG_FRAME        (~PAGE_MASK)
   79 #define PG_PS_FRAME     (0xffc00000)
   80 #endif
   81 #define PG_PROT         (PG_RW|PG_U)    /* all protection bits . */
   82 #define PG_N            (PG_NC_PWT|PG_NC_PCD)   /* Non-cacheable */
   83 
   84 /* Page level cache control fields used to determine the PAT type */
   85 #define PG_PDE_CACHE    (PG_PDE_PAT | PG_NC_PWT | PG_NC_PCD)
   86 #define PG_PTE_CACHE    (PG_PTE_PAT | PG_NC_PWT | PG_NC_PCD)
   87 
   88 /*
   89  * Promotion to a 2 or 4MB (PDE) page mapping requires that the corresponding
   90  * 4KB (PTE) page mappings have identical settings for the following fields:
   91  */
   92 #define PG_PTE_PROMOTE  (PG_MANAGED | PG_W | PG_G | PG_PTE_PAT | \
   93             PG_M | PG_A | PG_NC_PCD | PG_NC_PWT | PG_U | PG_RW | PG_V)
   94 
   95 /*
   96  * Page Protection Exception bits
   97  */
   98 
   99 #define PGEX_P          0x01    /* Protection violation vs. not present */
  100 #define PGEX_W          0x02    /* during a Write cycle */
  101 #define PGEX_U          0x04    /* access from User mode (UPL) */
  102 #define PGEX_RSV        0x08    /* reserved PTE field is non-zero */
  103 #define PGEX_I          0x10    /* during an instruction fetch */
  104 
  105 /*
  106  * Size of Kernel address space.  This is the number of page table pages
  107  * (4MB each) to use for the kernel.  256 pages == 1 Gigabyte.
  108  * This **MUST** be a multiple of 4 (eg: 252, 256, 260, etc).
  109  * For PAE, the page table page unit size is 2MB.  This means that 512 pages
  110  * is 1 Gigabyte.  Double everything.  It must be a multiple of 8 for PAE.
  111  */
  112 #ifndef KVA_PAGES
  113 #ifdef PAE
  114 #define KVA_PAGES       512
  115 #else
  116 #define KVA_PAGES       256
  117 #endif
  118 #endif
  119 
  120 /*
  121  * Pte related macros
  122  */
  123 #define VADDR(pdi, pti) ((vm_offset_t)(((pdi)<<PDRSHIFT)|((pti)<<PAGE_SHIFT)))
  124 
  125 /* Initial number of kernel page tables. */
  126 #ifndef NKPT
  127 #ifdef PAE
  128 /* 152 page tables needed to map 16G (76B "struct vm_page", 2M page tables). */
  129 #define NKPT            240
  130 #else
  131 /* 18 page tables needed to map 4G (72B "struct vm_page", 4M page tables). */
  132 #define NKPT            30
  133 #endif
  134 #endif
  135 
  136 #ifndef NKPDE
  137 #define NKPDE   (KVA_PAGES)     /* number of page tables/pde's */
  138 #endif
  139 
  140 /*
  141  * The *PTDI values control the layout of virtual memory
  142  *
  143  * XXX This works for now, but I am not real happy with it, I'll fix it
  144  * right after I fix locore.s and the magic 28K hole
  145  */
  146 #define KPTDI           (NPDEPTD-NKPDE) /* start of kernel virtual pde's */
  147 #define PTDPTDI         (KPTDI-NPGPTD)  /* ptd entry that points to ptd! */
  148 
  149 /*
  150  * XXX doesn't really belong here I guess...
  151  */
  152 #define ISA_HOLE_START    0xa0000
  153 #define ISA_HOLE_LENGTH (0x100000-ISA_HOLE_START)
  154 
  155 #ifndef LOCORE
  156 
  157 #include <sys/queue.h>
  158 #include <sys/_cpuset.h>
  159 #include <sys/_lock.h>
  160 #include <sys/_mutex.h>
  161 
  162 #ifdef PAE
  163 
  164 typedef uint64_t pdpt_entry_t;
  165 typedef uint64_t pd_entry_t;
  166 typedef uint64_t pt_entry_t;
  167 
  168 #define PTESHIFT        (3)
  169 #define PDESHIFT        (3)
  170 
  171 #else
  172 
  173 typedef uint32_t pd_entry_t;
  174 typedef uint32_t pt_entry_t;
  175 
  176 #define PTESHIFT        (2)
  177 #define PDESHIFT        (2)
  178 
  179 #endif
  180 
  181 /*
  182  * Address of current address space page table maps and directories.
  183  */
  184 #ifdef _KERNEL
  185 extern pt_entry_t PTmap[];
  186 extern pd_entry_t PTD[];
  187 extern pd_entry_t PTDpde[];
  188 
  189 #ifdef PAE
  190 extern pdpt_entry_t *IdlePDPT;
  191 #endif
  192 extern pd_entry_t *IdlePTD;     /* physical address of "Idle" state directory */
  193 
  194 /*
  195  * Translate a virtual address to the kernel virtual address of its page table
  196  * entry (PTE).  This can be used recursively.  If the address of a PTE as
  197  * previously returned by this macro is itself given as the argument, then the
  198  * address of the page directory entry (PDE) that maps the PTE will be
  199  * returned.
  200  *
  201  * This macro may be used before pmap_bootstrap() is called.
  202  */
  203 #define vtopte(va)      (PTmap + i386_btop(va))
  204 
  205 /*
  206  * Translate a virtual address to its physical address.
  207  *
  208  * This macro may be used before pmap_bootstrap() is called.
  209  */
  210 #define vtophys(va)     pmap_kextract((vm_offset_t)(va))
  211 
  212 #if defined(XEN)
  213 #include <sys/param.h>
  214 #include <machine/xen/xen-os.h>
  215 #include <machine/xen/xenvar.h>
  216 #include <machine/xen/xenpmap.h>
  217 
  218 extern pt_entry_t pg_nx;
  219 
  220 #define PG_KERNEL  (PG_V | PG_A | PG_RW | PG_M)
  221 
  222 #define MACH_TO_VM_PAGE(ma) PHYS_TO_VM_PAGE(xpmap_mtop((ma)))
  223 #define VM_PAGE_TO_MACH(m) xpmap_ptom(VM_PAGE_TO_PHYS((m)))
  224 
  225 #define VTOM(va) xpmap_ptom(VTOP(va))
  226 
  227 static __inline vm_paddr_t
  228 pmap_kextract_ma(vm_offset_t va)
  229 {
  230         vm_paddr_t ma;
  231         if ((ma = PTD[va >> PDRSHIFT]) & PG_PS) {
  232                 ma = (ma & ~(NBPDR - 1)) | (va & (NBPDR - 1));
  233         } else {
  234                 ma = (*vtopte(va) & PG_FRAME) | (va & PAGE_MASK);
  235         }
  236         return ma;
  237 }
  238 
  239 static __inline vm_paddr_t
  240 pmap_kextract(vm_offset_t va)
  241 {
  242         return xpmap_mtop(pmap_kextract_ma(va));
  243 }
  244 #define vtomach(va)     pmap_kextract_ma(((vm_offset_t) (va)))
  245 
  246 vm_paddr_t pmap_extract_ma(struct pmap *pmap, vm_offset_t va);
  247 
  248 void    pmap_kenter_ma(vm_offset_t va, vm_paddr_t pa);
  249 void    pmap_map_readonly(struct pmap *pmap, vm_offset_t va, int len);
  250 void    pmap_map_readwrite(struct pmap *pmap, vm_offset_t va, int len);
  251 
  252 static __inline pt_entry_t
  253 pte_load_store(pt_entry_t *ptep, pt_entry_t v)
  254 {
  255         pt_entry_t r;
  256 
  257         r = *ptep;
  258         PT_SET_VA(ptep, v, TRUE);
  259         return (r);
  260 }
  261 
  262 static __inline pt_entry_t
  263 pte_load_store_ma(pt_entry_t *ptep, pt_entry_t v)
  264 {
  265         pt_entry_t r;
  266 
  267         r = *ptep;
  268         PT_SET_VA_MA(ptep, v, TRUE);
  269         return (r);
  270 }
  271 
  272 #define pte_load_clear(ptep)    pte_load_store((ptep), (pt_entry_t)0ULL)
  273 
  274 #define pte_store(ptep, pte)    pte_load_store((ptep), (pt_entry_t)pte)
  275 #define pte_store_ma(ptep, pte) pte_load_store_ma((ptep), (pt_entry_t)pte)
  276 #define pde_store_ma(ptep, pte) pte_load_store_ma((ptep), (pt_entry_t)pte)
  277 
  278 #elif !defined(XEN)
  279 
  280 /*
  281  * KPTmap is a linear mapping of the kernel page table.  It differs from the
  282  * recursive mapping in two ways: (1) it only provides access to kernel page
  283  * table pages, and not user page table pages, and (2) it provides access to
  284  * a kernel page table page after the corresponding virtual addresses have
  285  * been promoted to a 2/4MB page mapping.
  286  *
  287  * KPTmap is first initialized by locore to support just NPKT page table
  288  * pages.  Later, it is reinitialized by pmap_bootstrap() to allow for
  289  * expansion of the kernel page table.
  290  */
  291 extern pt_entry_t *KPTmap;
  292 
  293 /*
  294  * Extract from the kernel page table the physical address that is mapped by
  295  * the given virtual address "va".
  296  *
  297  * This function may be used before pmap_bootstrap() is called.
  298  */
  299 static __inline vm_paddr_t
  300 pmap_kextract(vm_offset_t va)
  301 {
  302         vm_paddr_t pa;
  303 
  304         if ((pa = PTD[va >> PDRSHIFT]) & PG_PS) {
  305                 pa = (pa & PG_PS_FRAME) | (va & PDRMASK);
  306         } else {
  307                 /*
  308                  * Beware of a concurrent promotion that changes the PDE at
  309                  * this point!  For example, vtopte() must not be used to
  310                  * access the PTE because it would use the new PDE.  It is,
  311                  * however, safe to use the old PDE because the page table
  312                  * page is preserved by the promotion.
  313                  */
  314                 pa = KPTmap[i386_btop(va)];
  315                 pa = (pa & PG_FRAME) | (va & PAGE_MASK);
  316         }
  317         return (pa);
  318 }
  319 #endif
  320 
  321 #if !defined(XEN)
  322 #define PT_UPDATES_FLUSH()
  323 #endif
  324 
  325 #if defined(PAE) && !defined(XEN)
  326 
  327 #define pde_cmpset(pdep, old, new)      atomic_cmpset_64_i586(pdep, old, new)
  328 #define pte_load_store(ptep, pte)       atomic_swap_64_i586(ptep, pte)
  329 #define pte_load_clear(ptep)            atomic_swap_64_i586(ptep, 0)
  330 #define pte_store(ptep, pte)            atomic_store_rel_64_i586(ptep, pte)
  331 
  332 extern pt_entry_t pg_nx;
  333 
  334 #elif !defined(PAE) && !defined(XEN)
  335 
  336 #define pde_cmpset(pdep, old, new)      atomic_cmpset_int(pdep, old, new)
  337 #define pte_load_store(ptep, pte)       atomic_swap_int(ptep, pte)
  338 #define pte_load_clear(ptep)            atomic_swap_int(ptep, 0)
  339 #define pte_store(ptep, pte) do { \
  340         *(u_int *)(ptep) = (u_int)(pte); \
  341 } while (0)
  342 
  343 #endif /* PAE */
  344 
  345 #define pte_clear(ptep)                 pte_store(ptep, 0)
  346 
  347 #define pde_store(pdep, pde)            pte_store(pdep, pde)
  348 
  349 #endif /* _KERNEL */
  350 
  351 /*
  352  * Pmap stuff
  353  */
  354 struct  pv_entry;
  355 struct  pv_chunk;
  356 
  357 struct md_page {
  358         TAILQ_HEAD(,pv_entry)   pv_list;
  359         int                     pat_mode;
  360 };
  361 
  362 struct pmap {
  363         struct mtx              pm_mtx;
  364         pd_entry_t              *pm_pdir;       /* KVA of page directory */
  365         TAILQ_HEAD(,pv_chunk)   pm_pvchunk;     /* list of mappings in pmap */
  366         cpuset_t                pm_active;      /* active on cpus */
  367         struct pmap_statistics  pm_stats;       /* pmap statistics */
  368         LIST_ENTRY(pmap)        pm_list;        /* List of all pmaps */
  369 #ifdef PAE
  370         pdpt_entry_t            *pm_pdpt;       /* KVA of page director pointer
  371                                                    table */
  372 #endif
  373         vm_page_t               pm_root;        /* spare page table pages */
  374 };
  375 
  376 typedef struct pmap     *pmap_t;
  377 
  378 #ifdef _KERNEL
  379 extern struct pmap      kernel_pmap_store;
  380 #define kernel_pmap     (&kernel_pmap_store)
  381 
  382 #define PMAP_LOCK(pmap)         mtx_lock(&(pmap)->pm_mtx)
  383 #define PMAP_LOCK_ASSERT(pmap, type) \
  384                                 mtx_assert(&(pmap)->pm_mtx, (type))
  385 #define PMAP_LOCK_DESTROY(pmap) mtx_destroy(&(pmap)->pm_mtx)
  386 #define PMAP_LOCK_INIT(pmap)    mtx_init(&(pmap)->pm_mtx, "pmap", \
  387                                     NULL, MTX_DEF | MTX_DUPOK)
  388 #define PMAP_LOCKED(pmap)       mtx_owned(&(pmap)->pm_mtx)
  389 #define PMAP_MTX(pmap)          (&(pmap)->pm_mtx)
  390 #define PMAP_TRYLOCK(pmap)      mtx_trylock(&(pmap)->pm_mtx)
  391 #define PMAP_UNLOCK(pmap)       mtx_unlock(&(pmap)->pm_mtx)
  392 #endif
  393 
  394 /*
  395  * For each vm_page_t, there is a list of all currently valid virtual
  396  * mappings of that page.  An entry is a pv_entry_t, the list is pv_list.
  397  */
  398 typedef struct pv_entry {
  399         vm_offset_t     pv_va;          /* virtual address for mapping */
  400         TAILQ_ENTRY(pv_entry)   pv_list;
  401 } *pv_entry_t;
  402 
  403 /*
  404  * pv_entries are allocated in chunks per-process.  This avoids the
  405  * need to track per-pmap assignments.
  406  */
  407 #define _NPCM   11
  408 #define _NPCPV  336
  409 struct pv_chunk {
  410         pmap_t                  pc_pmap;
  411         TAILQ_ENTRY(pv_chunk)   pc_list;
  412         uint32_t                pc_map[_NPCM];  /* bitmap; 1 = free */
  413         TAILQ_ENTRY(pv_chunk)   pc_lru;
  414         struct pv_entry         pc_pventry[_NPCPV];
  415 };
  416 
  417 #ifdef  _KERNEL
  418 
  419 extern caddr_t  CADDR3;
  420 extern pt_entry_t *CMAP3;
  421 extern vm_paddr_t phys_avail[];
  422 extern vm_paddr_t dump_avail[];
  423 extern int pseflag;
  424 extern int pgeflag;
  425 extern char *ptvmmap;           /* poor name! */
  426 extern vm_offset_t virtual_avail;
  427 extern vm_offset_t virtual_end;
  428 
  429 #define pmap_page_get_memattr(m)        ((vm_memattr_t)(m)->md.pat_mode)
  430 #define pmap_page_is_write_mapped(m)    (((m)->aflags & PGA_WRITEABLE) != 0)
  431 #define pmap_unmapbios(va, sz)  pmap_unmapdev((va), (sz))
  432 
  433 /*
  434  * Only the following functions or macros may be used before pmap_bootstrap()
  435  * is called: pmap_kenter(), pmap_kextract(), pmap_kremove(), vtophys(), and
  436  * vtopte().
  437  */
  438 void    pmap_bootstrap(vm_paddr_t);
  439 int     pmap_cache_bits(int mode, boolean_t is_pde);
  440 int     pmap_change_attr(vm_offset_t, vm_size_t, int);
  441 void    pmap_init_pat(void);
  442 void    pmap_kenter(vm_offset_t va, vm_paddr_t pa);
  443 void    *pmap_kenter_temporary(vm_paddr_t pa, int i);
  444 void    pmap_kremove(vm_offset_t);
  445 void    *pmap_mapbios(vm_paddr_t, vm_size_t);
  446 void    *pmap_mapdev(vm_paddr_t, vm_size_t);
  447 void    *pmap_mapdev_attr(vm_paddr_t, vm_size_t, int);
  448 boolean_t pmap_page_is_mapped(vm_page_t m);
  449 void    pmap_page_set_memattr(vm_page_t m, vm_memattr_t ma);
  450 void    pmap_unmapdev(vm_offset_t, vm_size_t);
  451 pt_entry_t *pmap_pte(pmap_t, vm_offset_t) __pure2;
  452 void    pmap_invalidate_page(pmap_t, vm_offset_t);
  453 void    pmap_invalidate_range(pmap_t, vm_offset_t, vm_offset_t);
  454 void    pmap_invalidate_all(pmap_t);
  455 void    pmap_invalidate_cache(void);
  456 void    pmap_invalidate_cache_pages(vm_page_t *pages, int count);
  457 void    pmap_invalidate_cache_range(vm_offset_t sva, vm_offset_t eva);
  458 
  459 #endif /* _KERNEL */
  460 
  461 #endif /* !LOCORE */
  462 
  463 #endif /* !_MACHINE_PMAP_H_ */

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