LCOM1920-T02G10

/*        $NetBSD: pmap.h,v 1.117 2014/04/21 19:12:11 christos 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.

 *

 * 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.

 */

/*

 * Copyright (c) 2001 Wasabi Systems, Inc.

 * All rights reserved.

 *

 * Written by Frank van der Linden for Wasabi Systems, 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.

 * 3. All advertising materials mentioning features or use of this software

 *    must display the following acknowledgement:

 *      This product includes software developed for the NetBSD Project by

 *      Wasabi Systems, Inc.

 * 4. The name of Wasabi Systems, Inc. may not be used to endorse

 *    or promote products derived from this software without specific prior

 *    written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC

 * 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.

 */

#ifndef        _I386_PMAP_H_

#define        _I386_PMAP_H_

#if defined(_KERNEL_OPT)

#include "opt_user_ldt.h"

#include "opt_xen.h"

#endif

#include <sys/atomic.h>

#include <i386/pte.h>

#include <machine/segments.h>

#if defined(_KERNEL)

#include <machine/cpufunc.h>

#endif

#include <uvm/uvm_object.h>

#ifdef XEN

#include <xen/xenfunc.h>

#include <xen/xenpmap.h>

#endif /* XEN */

/*

 * see pte.h for a description of i386 MMU terminology and hardware

 * interface.

 *

 * a pmap describes a processes' 4GB virtual address space.  when PAE

 * is not in use, 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->766        0x0 -> 0xbfc00000        user address space

 * 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)

 *                        <end>

 *

 *

 * 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 0xfffff000 (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 / PAGE_SIZE) * 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 temporarily load this pmap, perform the operation, and mark

 * the currently active one as pending lazy reload.

 *

 * 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 -> 0xc0400000)

 *   |    |

 *   +----+

 *

 * note that the PDE#767 VA (0xbfc00000) is defined as "PTE_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 0xbfeff000

 *   | 768| -> maps contents of first kernel PTP

 *   |    |

 *   |1023|

 *   +----+

 *

 * note that mapping of the PDP at PTP#767's VA (0xbfeff000) 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.

 *

 * - PAE support -

 * ---------------

 *

 * PAE adds another layer of indirection during address translation, breaking

 * up the translation process in 3 different levels:

 * - L3 page directory, containing 4 * 64-bits addresses (index determined by

 * bits [31:30] from the virtual address). This breaks up the address space

 * in 4 1GB regions.

 * - the PD (L2), containing 512 64-bits addresses, breaking each L3 region

 * in 512 * 2MB regions.

 * - the PT (L1), also containing 512 64-bits addresses (at L1, the size of

 * the pages is still 4K).

 *

 * The kernel virtual space is mapped by the last entry in the L3 page,

 * the first 3 entries mapping the user VA space.

 *

 * Because the L3 has only 4 entries of 1GB each, we can't use recursive

 * mappings at this level for PDP_PDE (this would eat up 2 of the 4GB

 * virtual space). There are also restrictions imposed by Xen on the

 * last entry of the L3 PD (reference count to this page cannot be

 * bigger than 1), which makes it hard to use one L3 page per pmap to

 * switch between pmaps using %cr3.

 *

 * As such, each CPU gets its own L3 page that is always loaded into its %cr3

 * (ci_pae_l3_pd in the associated cpu_info struct). We claim that the VM has

 * only a 2-level PTP (similar to the non-PAE case). L2 PD is now 4 contiguous

 * pages long (corresponding to the 4 entries of the L3), and the different

 * index/slots (like PDP_PDE) are adapted accordingly.

 * 

 * Kernel space remains in L3[3], L3[0-2] maps the user VA space. Switching

 * between pmaps consists in modifying the first 3 entries of the CPU's L3 page.

 *

 * PTE_BASE will need 4 entries in the L2 PD pages to map the L2 pages

 * recursively.

 *

 * In addition, for Xen, we can't recursively map L3[3] (Xen wants the ref

 * count on this page to be exactly one), so we use a shadow PD page for

 * the last L2 PD. The shadow page could be static too, but to make pm_pdir[]

 * contiguous we'll allocate/copy one page per pmap.

 */

/*

 * Mask to get rid of the sign-extended part of addresses.

 */

#define VA_SIGN_MASK                0

#define VA_SIGN_NEG(va)                ((va) | VA_SIGN_MASK)

/*

 * XXXfvdl this one's not right.

 */

#define VA_SIGN_POS(va)                ((va) & ~VA_SIGN_MASK)

/*

 * the following defines identify the slots used as described above.

 */

#ifdef PAE

#define L2_SLOT_PTE        (KERNBASE/NBPD_L2-4) /* 1532: for recursive PDP map */

#define L2_SLOT_KERN        (KERNBASE/NBPD_L2)   /* 1536: start of kernel space */

#else /* PAE */

#define L2_SLOT_PTE        (KERNBASE/NBPD_L2-1) /* 767: for recursive PDP map */

#define L2_SLOT_KERN        (KERNBASE/NBPD_L2)   /* 768: start of kernel space */

#endif /* PAE */

#define        L2_SLOT_KERNBASE L2_SLOT_KERN

#define PDIR_SLOT_KERN        L2_SLOT_KERN

#define PDIR_SLOT_PTE        L2_SLOT_PTE

/*

 * the following defines give the virtual addresses of various MMU

 * data structures:

 * PTE_BASE: the base VA of the linear PTE mappings

 * PDP_BASE: the base VA of the recursive mapping of the PDP

 * PDP_PDE: the VA of the PDE that points back to the PDP

 */

#define PTE_BASE  ((pt_entry_t *) (PDIR_SLOT_PTE * NBPD_L2))

#define L1_BASE                PTE_BASE

#define L2_BASE ((pd_entry_t *)((char *)L1_BASE + L2_SLOT_PTE * NBPD_L1))

#define PDP_PDE                (L2_BASE + PDIR_SLOT_PTE)

#define PDP_BASE        L2_BASE

/* largest value (-1 for APTP space) */

#define NKL2_MAX_ENTRIES        (NTOPLEVEL_PDES - (KERNBASE/NBPD_L2) - 1)

#define NKL1_MAX_ENTRIES        (unsigned long)(NKL2_MAX_ENTRIES * NPDPG)

#define NKL2_KIMG_ENTRIES        0        /* XXX unused */

#define NKL2_START_ENTRIES        0        /* XXX computed on runtime */

#define NKL1_START_ENTRIES        0        /* XXX unused */

#ifndef XEN

#define NTOPLEVEL_PDES                (PAGE_SIZE * PDP_SIZE / (sizeof (pd_entry_t)))

#else        /* !XEN */

#ifdef  PAE

#define NTOPLEVEL_PDES                1964        /* 1964-2047 reserved by Xen */

#else        /* PAE */

#define NTOPLEVEL_PDES                1008        /* 1008-1023 reserved by Xen */

#endif        /* PAE */

#endif  /* !XEN */

#define NPDPG                        (PAGE_SIZE / sizeof (pd_entry_t))

#define PTP_MASK_INITIALIZER        { L1_FRAME, L2_FRAME }

#define PTP_SHIFT_INITIALIZER        { L1_SHIFT, L2_SHIFT }

#define NKPTP_INITIALIZER        { NKL1_START_ENTRIES, NKL2_START_ENTRIES }

#define NKPTPMAX_INITIALIZER        { NKL1_MAX_ENTRIES, NKL2_MAX_ENTRIES }

#define NBPD_INITIALIZER        { NBPD_L1, NBPD_L2 }

#define PDES_INITIALIZER        { L2_BASE }

#define PTP_LEVELS        2

/*

 * 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 */

#define PG_X                PG_AVAIL3        /* executable mapping */

/*

 * Number of PTE's per cache line.  4 byte pte, 32-byte cache line

 * Used to avoid false sharing of cache lines.

 */

#ifdef PAE

#define NPTECL                4

#else

#define NPTECL                8

#endif

#include <x86/pmap.h>

#ifndef XEN

#define pmap_pa2pte(a)                        (a)

#define pmap_pte2pa(a)                        ((a) & PG_FRAME)

#define pmap_pte_set(p, n)                do { *(p) = (n); } while (0)

#define pmap_pte_flush()                /* nothing */

#ifdef PAE

#define pmap_pte_cas(p, o, n)                atomic_cas_64((p), (o), (n))

#define pmap_pte_testset(p, n)                \

    atomic_swap_64((volatile uint64_t *)p, n)

#define pmap_pte_setbits(p, b)                \

    atomic_or_64((volatile uint64_t *)p, b)

#define pmap_pte_clearbits(p, b)        \

    atomic_and_64((volatile uint64_t *)p, ~(b))

#else /* PAE */

#define pmap_pte_cas(p, o, n)                atomic_cas_32((p), (o), (n))

#define pmap_pte_testset(p, n)                \

    atomic_swap_ulong((volatile unsigned long *)p, n)

#define pmap_pte_setbits(p, b)                \

    atomic_or_ulong((volatile unsigned long *)p, b)

#define pmap_pte_clearbits(p, b)        \

    atomic_and_ulong((volatile unsigned long *)p, ~(b))

#endif /* PAE */

#else /* XEN */

extern kmutex_t pte_lock;

static __inline pt_entry_t

pmap_pa2pte(paddr_t pa)

{

        return (pt_entry_t)xpmap_ptom_masked(pa);

}

static __inline paddr_t

pmap_pte2pa(pt_entry_t pte)

{

        return xpmap_mtop_masked(pte & PG_FRAME);

}

static __inline void

pmap_pte_set(pt_entry_t *pte, pt_entry_t npte)

{

        int s = splvm();

        xpq_queue_pte_update(xpmap_ptetomach(pte), npte);

        splx(s);

}

static __inline pt_entry_t

pmap_pte_cas(volatile pt_entry_t *ptep, pt_entry_t o, pt_entry_t n)

{

        pt_entry_t opte;

        mutex_enter(&pte_lock);

        opte = *ptep;

        if (opte == o) {

                xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(ptep)), n);

                xpq_flush_queue();

        }

        mutex_exit(&pte_lock);

        return opte;

}

static __inline pt_entry_t

pmap_pte_testset(volatile pt_entry_t *pte, pt_entry_t npte)

{

        pt_entry_t opte;

        mutex_enter(&pte_lock);

        opte = *pte;

        xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(pte)),

            npte);

        xpq_flush_queue();

        mutex_exit(&pte_lock);

        return opte;

}

static __inline void

pmap_pte_setbits(volatile pt_entry_t *pte, pt_entry_t bits)

{

        mutex_enter(&pte_lock);

        xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(pte)), (*pte) | bits);

        xpq_flush_queue();

        mutex_exit(&pte_lock);

}

static __inline void

pmap_pte_clearbits(volatile pt_entry_t *pte, pt_entry_t bits)

{        

        mutex_enter(&pte_lock);

        xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(pte)),

            (*pte) & ~bits);

        xpq_flush_queue();

        mutex_exit(&pte_lock);

}

static __inline void

pmap_pte_flush(void)

{

        int s = splvm();

        xpq_flush_queue();

        splx(s);

}

#endif

struct vm_map;

struct trapframe;

struct pcb;

int        pmap_exec_fixup(struct vm_map *, struct trapframe *, struct pcb *);

void        pmap_ldt_cleanup(struct lwp *);

#include <x86/pmap_pv.h>

#define        __HAVE_VM_PAGE_MD

#define        VM_MDPAGE_INIT(pg) \

        memset(&(pg)->mdpage, 0, sizeof((pg)->mdpage)); \

        PMAP_PAGE_INIT(&(pg)->mdpage.mp_pp)

struct vm_page_md {

        struct pmap_page mp_pp;

};

#endif        /* _I386_PMAP_H_ */