/* $NetBSD: pmap.h,v 1.102 2008/01/23 19:46:44 bouyer 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. */ /* * 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 #include #include #if defined(_KERNEL) #include #endif #include #ifdef XEN #include #include #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) * 1023 0xffc00000-> "alternate" recursive PDP mapping * (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 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 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 -> 0xc0400000) * | | * |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 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. * "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). * * When PAE is in use, the L3 page directory breaks up the address space in * 4 1GB * regions, each of them broken in 512 2MB regions by the L2 PD * (the size of the pages at the L1 level 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 and APDP_PDE (this would eat 2 of the * 4GB virtual space). There's also restrictions imposed by Xen on the * last entry of the L3 PD, which makes it hard to use one L3 page per pmap * switch %cr3 to switch pmaps. So we use one static L3 page which is * always loaded in %cr3, and we use it as 2 virtual PD pointers: one for * kenrel space (L3[3], always loaded), and one for user space (in fact the * first 3 entries of the L3 PD), and we claim the VM has only a 2-level * PTP (with the L2 index extended by 2 bytes). * PTE_BASE and APTE_BASE will need 4 entries in the L2 page table. * In addition, we can't recursively map L3[3] (Xen wants the ref count on * this page to be exactly once), so we use a shadow PD page for the last * L2 PD. The shadow page could be static too, but to make pm_pdir[] * contigous we'll allocate/copy one page per pmap. */ /* XXX MP should we allocate one APDP_PDE per processor?? */ /* * 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 */ #define L2_SLOT_KERNBASE L2_SLOT_KERN #define L2_SLOT_APTE 1960 /* 1964-2047 reserved by Xen */ #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 */ #define L2_SLOT_KERNBASE L2_SLOT_KERN #ifndef XEN #define L2_SLOT_APTE 1023 /* 1023: alternative recursive slot */ #else #define L2_SLOT_APTE 1007 /* 1008-1023 reserved by Xen */ #endif #endif /* PAE */ #define PDIR_SLOT_KERN L2_SLOT_KERN #define PDIR_SLOT_PTE L2_SLOT_PTE #define PDIR_SLOT_APTE L2_SLOT_APTE /* * 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 * PDP_BASE and APDP_BASE: the base VA of the recursive mapping of the PDP * PDP_PDE and APDP_PDE: the VA of the PDE that points back to the PDP/APDP */ #define PTE_BASE ((pt_entry_t *) (PDIR_SLOT_PTE * NBPD_L2)) #define APTE_BASE ((pt_entry_t *) (VA_SIGN_NEG((PDIR_SLOT_APTE * NBPD_L2)))) #define L1_BASE PTE_BASE #define AL1_BASE APTE_BASE #define L2_BASE ((pd_entry_t *)((char *)L1_BASE + L2_SLOT_PTE * NBPD_L1)) #define AL2_BASE ((pd_entry_t *)((char *)AL1_BASE + L2_SLOT_PTE * NBPD_L1)) #define PDP_PDE (L2_BASE + PDIR_SLOT_PTE) #ifdef PAE /* * when PAE is in use we can't write APDP_PDE though the recursive mapping, * because it points to the shadow PD. Use the kernel PD instead, which is * static */ #define APDP_PDE (&pmap_kl2pd[l2tol2(PDIR_SLOT_APTE)]) #define APDP_PDE_SHADOW (L2_BASE + PDIR_SLOT_APTE) #else /* PAE */ #define APDP_PDE (L2_BASE + PDIR_SLOT_APTE) #endif /* PAE */ #define PDP_BASE L2_BASE #define APDP_BASE AL2_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 */ #ifdef PAE #define NTOPLEVEL_PDES (PAGE_SIZE * 4 / (sizeof (pd_entry_t))) #else #define NTOPLEVEL_PDES (PAGE_SIZE / (sizeof (pd_entry_t))) #endif #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 APDES_INITIALIZER { AL2_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 #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_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)) #define pmap_pte_flush() /* nothing */ #else 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) { int s = splvm(); pt_entry_t opte = *ptep; if (opte == o) { xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(ptep)), n); xpq_flush_queue(); } splx(s); return opte; } static __inline pt_entry_t pmap_pte_testset(volatile pt_entry_t *pte, pt_entry_t npte) { int s = splvm(); pt_entry_t opte = *pte; xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(pte)), npte); xpq_flush_queue(); splx(s); return opte; } static __inline void pmap_pte_setbits(volatile pt_entry_t *pte, pt_entry_t bits) { int s = splvm(); xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(pte)), (*pte) | bits); xpq_flush_queue(); splx(s); } static __inline void pmap_pte_clearbits(volatile pt_entry_t *pte, pt_entry_t bits) { int s = splvm(); xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(pte)), (*pte) & ~bits); xpq_flush_queue(); splx(s); } static __inline void pmap_pte_flush(void) { int s = splvm(); xpq_flush_queue(); splx(s); } #endif #ifdef PAE /* addresses of static pages used for PAE pmap: */ /* the L3 page */ pd_entry_t *pmap_l3pd; paddr_t pmap_l3paddr; /* the kernel's L2 page */ pd_entry_t *pmap_kl2pd; paddr_t pmap_kl2paddr; #endif struct trapframe; int pmap_exec_fixup(struct vm_map *, struct trapframe *, struct pcb *); void pmap_ldt_cleanup(struct lwp *); #endif /* _I386_PMAP_H_ */