1 /* $NetBSD: pmap.h,v 1.102 2008/01/23 19:46:44 bouyer Exp $ */
5 * Copyright (c) 1997 Charles D. Cranor and Washington University.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgment:
18 * This product includes software developed by Charles D. Cranor and
19 * Washington University.
20 * 4. The name of the author may not be used to endorse or promote products
21 * derived from this software without specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 * Copyright (c) 2001 Wasabi Systems, Inc.
37 * All rights reserved.
39 * Written by Frank van der Linden for Wasabi Systems, Inc.
41 * Redistribution and use in source and binary forms, with or without
42 * modification, are permitted provided that the following conditions
44 * 1. Redistributions of source code must retain the above copyright
45 * notice, this list of conditions and the following disclaimer.
46 * 2. Redistributions in binary form must reproduce the above copyright
47 * notice, this list of conditions and the following disclaimer in the
48 * documentation and/or other materials provided with the distribution.
49 * 3. All advertising materials mentioning features or use of this software
50 * must display the following acknowledgement:
51 * This product includes software developed for the NetBSD Project by
52 * Wasabi Systems, Inc.
53 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
54 * or promote products derived from this software without specific prior
57 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
58 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
59 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
60 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
61 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
62 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
63 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
64 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
65 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
66 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
67 * POSSIBILITY OF SUCH DAMAGE.
73 #if defined(_KERNEL_OPT)
74 #include "opt_user_ldt.h"
78 #include <sys/atomic.h>
81 #include <machine/segments.h>
83 #include <machine/cpufunc.h>
86 #include <uvm/uvm_object.h>
88 #include <xen/xenfunc.h>
89 #include <xen/xenpmap.h>
93 * see pte.h for a description of i386 MMU terminology and hardware
96 * a pmap describes a processes' 4GB virtual address space. when PAE
97 * is not in use, this virtual address space can be broken up into 1024 4MB
98 * regions which are described by PDEs in the PDP. the PDEs are defined as
101 * (ranges are inclusive -> exclusive, just like vm_map_entry start/end)
102 * (the following assumes that KERNBASE is 0xc0000000)
104 * PDE#s VA range usage
105 * 0->766 0x0 -> 0xbfc00000 user address space
106 * 767 0xbfc00000-> recursive mapping of PDP (used for
107 * 0xc0000000 linear mapping of PTPs)
108 * 768->1023 0xc0000000-> kernel address space (constant
109 * 0xffc00000 across all pmap's/processes)
110 * 1023 0xffc00000-> "alternate" recursive PDP mapping
111 * <end> (for other pmaps)
114 * note: a recursive PDP mapping provides a way to map all the PTEs for
115 * a 4GB address space into a linear chunk of virtual memory. in other
116 * words, the PTE for page 0 is the first int mapped into the 4MB recursive
117 * area. the PTE for page 1 is the second int. the very last int in the
118 * 4MB range is the PTE that maps VA 0xfffff000 (the last page in a 4GB
121 * all pmap's PD's must have the same values in slots 768->1023 so that
122 * the kernel is always mapped in every process. these values are loaded
123 * into the PD at pmap creation time.
125 * at any one time only one pmap can be active on a processor. this is
126 * the pmap whose PDP is pointed to by processor register %cr3. this pmap
127 * will have all its PTEs mapped into memory at the recursive mapping
128 * point (slot #767 as show above). when the pmap code wants to find the
129 * PTE for a virtual address, all it has to do is the following:
131 * address of PTE = (767 * 4MB) + (VA / PAGE_SIZE) * sizeof(pt_entry_t)
132 * = 0xbfc00000 + (VA / 4096) * 4
134 * what happens if the pmap layer is asked to perform an operation
135 * on a pmap that is not the one which is currently active? in that
136 * case we take the PA of the PDP of non-active pmap and put it in
137 * slot 1023 of the active pmap. this causes the non-active pmap's
138 * PTEs to get mapped in the final 4MB of the 4GB address space
139 * (e.g. starting at 0xffc00000).
141 * the following figure shows the effects of the recursive PDP mapping:
145 * | 0| -> PTP#0 that maps VA 0x0 -> 0x400000
148 * | 767| -> points back to PDP (%cr3) mapping VA 0xbfc00000 -> 0xc0000000
149 * | 768| -> first kernel PTP (maps 0xc0000000 -> 0xc0400000)
151 * |1023| -> points to alternate pmap's PDP (maps 0xffc00000 -> end)
154 * note that the PDE#767 VA (0xbfc00000) is defined as "PTE_BASE"
155 * note that the PDE#1023 VA (0xffc00000) is defined as "APTE_BASE"
157 * starting at VA 0xbfc00000 the current active PDP (%cr3) acts as a
160 * PTP#767 == PDP(%cr3) => maps VA 0xbfc00000 -> 0xc0000000
162 * | 0| -> maps the contents of PTP#0 at VA 0xbfc00000->0xbfc01000
165 * | 767| -> maps contents of PTP#767 (the PDP) at VA 0xbfeff000
166 * | 768| -> maps contents of first kernel PTP
171 * note that mapping of the PDP at PTP#767's VA (0xbfeff000) is
172 * defined as "PDP_BASE".... within that mapping there are two
174 * "PDP_PDE" (0xbfeffbfc) is the VA of the PDE in the PDP
175 * which points back to itself.
176 * "APDP_PDE" (0xbfeffffc) is the VA of the PDE in the PDP which
177 * establishes the recursive mapping of the alternate pmap.
178 * to set the alternate PDP, one just has to put the correct
179 * PA info in *APDP_PDE.
181 * note that in the APTE_BASE space, the APDP appears at VA
182 * "APDP_BASE" (0xfffff000).
184 * When PAE is in use, the L3 page directory breaks up the address space in
185 * 4 1GB * regions, each of them broken in 512 2MB regions by the L2 PD
186 * (the size of the pages at the L1 level is still 4K).
187 * The kernel virtual space is mapped by the last entry in the L3 page,
188 * the first 3 entries mapping the user VA space.
189 * Because the L3 has only 4 entries of 1GB each, we can't use recursive
190 * mappings at this level for PDP_PDE and APDP_PDE (this would eat 2 of the
191 * 4GB virtual space). There's also restrictions imposed by Xen on the
192 * last entry of the L3 PD, which makes it hard to use one L3 page per pmap
193 * switch %cr3 to switch pmaps. So we use one static L3 page which is
194 * always loaded in %cr3, and we use it as 2 virtual PD pointers: one for
195 * kenrel space (L3[3], always loaded), and one for user space (in fact the
196 * first 3 entries of the L3 PD), and we claim the VM has only a 2-level
197 * PTP (with the L2 index extended by 2 bytes).
198 * PTE_BASE and APTE_BASE will need 4 entries in the L2 page table.
199 * In addition, we can't recursively map L3[3] (Xen wants the ref count on
200 * this page to be exactly once), so we use a shadow PD page for the last
201 * L2 PD. The shadow page could be static too, but to make pm_pdir[]
202 * contigous we'll allocate/copy one page per pmap.
204 /* XXX MP should we allocate one APDP_PDE per processor?? */
207 * Mask to get rid of the sign-extended part of addresses.
209 #define VA_SIGN_MASK 0
210 #define VA_SIGN_NEG(va) ((va) | VA_SIGN_MASK)
212 * XXXfvdl this one's not right.
214 #define VA_SIGN_POS(va) ((va) & ~VA_SIGN_MASK)
217 * the following defines identify the slots used as described above.
220 #define L2_SLOT_PTE (KERNBASE/NBPD_L2-4) /* 1532: for recursive PDP map */
221 #define L2_SLOT_KERN (KERNBASE/NBPD_L2) /* 1536: start of kernel space */
222 #define L2_SLOT_KERNBASE L2_SLOT_KERN
223 #define L2_SLOT_APTE 1960 /* 1964-2047 reserved by Xen */
225 #define L2_SLOT_PTE (KERNBASE/NBPD_L2-1) /* 767: for recursive PDP map */
226 #define L2_SLOT_KERN (KERNBASE/NBPD_L2) /* 768: start of kernel space */
227 #define L2_SLOT_KERNBASE L2_SLOT_KERN
229 #define L2_SLOT_APTE 1023 /* 1023: alternative recursive slot */
231 #define L2_SLOT_APTE 1007 /* 1008-1023 reserved by Xen */
236 #define PDIR_SLOT_KERN L2_SLOT_KERN
237 #define PDIR_SLOT_PTE L2_SLOT_PTE
238 #define PDIR_SLOT_APTE L2_SLOT_APTE
241 * the following defines give the virtual addresses of various MMU
243 * PTE_BASE and APTE_BASE: the base VA of the linear PTE mappings
244 * PDP_BASE and APDP_BASE: the base VA of the recursive mapping of the PDP
245 * PDP_PDE and APDP_PDE: the VA of the PDE that points back to the PDP/APDP
248 #define PTE_BASE ((pt_entry_t *) (PDIR_SLOT_PTE * NBPD_L2))
249 #define APTE_BASE ((pt_entry_t *) (VA_SIGN_NEG((PDIR_SLOT_APTE * NBPD_L2))))
251 #define L1_BASE PTE_BASE
252 #define AL1_BASE APTE_BASE
254 #define L2_BASE ((pd_entry_t *)((char *)L1_BASE + L2_SLOT_PTE * NBPD_L1))
255 #define AL2_BASE ((pd_entry_t *)((char *)AL1_BASE + L2_SLOT_PTE * NBPD_L1))
257 #define PDP_PDE (L2_BASE + PDIR_SLOT_PTE)
260 * when PAE is in use we can't write APDP_PDE though the recursive mapping,
261 * because it points to the shadow PD. Use the kernel PD instead, which is
264 #define APDP_PDE (&pmap_kl2pd[l2tol2(PDIR_SLOT_APTE)])
265 #define APDP_PDE_SHADOW (L2_BASE + PDIR_SLOT_APTE)
267 #define APDP_PDE (L2_BASE + PDIR_SLOT_APTE)
270 #define PDP_BASE L2_BASE
271 #define APDP_BASE AL2_BASE
273 /* largest value (-1 for APTP space) */
274 #define NKL2_MAX_ENTRIES (NTOPLEVEL_PDES - (KERNBASE/NBPD_L2) - 1)
275 #define NKL1_MAX_ENTRIES (unsigned long)(NKL2_MAX_ENTRIES * NPDPG)
277 #define NKL2_KIMG_ENTRIES 0 /* XXX unused */
279 #define NKL2_START_ENTRIES 0 /* XXX computed on runtime */
280 #define NKL1_START_ENTRIES 0 /* XXX unused */
283 #define NTOPLEVEL_PDES (PAGE_SIZE * 4 / (sizeof (pd_entry_t)))
285 #define NTOPLEVEL_PDES (PAGE_SIZE / (sizeof (pd_entry_t)))
288 #define NPDPG (PAGE_SIZE / sizeof (pd_entry_t))
290 #define PTP_MASK_INITIALIZER { L1_FRAME, L2_FRAME }
291 #define PTP_SHIFT_INITIALIZER { L1_SHIFT, L2_SHIFT }
292 #define NKPTP_INITIALIZER { NKL1_START_ENTRIES, NKL2_START_ENTRIES }
293 #define NKPTPMAX_INITIALIZER { NKL1_MAX_ENTRIES, NKL2_MAX_ENTRIES }
294 #define NBPD_INITIALIZER { NBPD_L1, NBPD_L2 }
295 #define PDES_INITIALIZER { L2_BASE }
296 #define APDES_INITIALIZER { AL2_BASE }
301 * PG_AVAIL usage: we make use of the ignored bits of the PTE
304 #define PG_W PG_AVAIL1 /* "wired" mapping */
305 #define PG_PVLIST PG_AVAIL2 /* mapping has entry on pvlist */
306 #define PG_X PG_AVAIL3 /* executable mapping */
309 * Number of PTE's per cache line. 4 byte pte, 32-byte cache line
310 * Used to avoid false sharing of cache lines.
318 #include <x86/pmap.h>
321 #define pmap_pa2pte(a) (a)
322 #define pmap_pte2pa(a) ((a) & PG_FRAME)
323 #define pmap_pte_set(p, n) do { *(p) = (n); } while (0)
324 #define pmap_pte_cas(p, o, n) atomic_cas_32((p), (o), (n))
325 #define pmap_pte_testset(p, n) \
326 atomic_swap_ulong((volatile unsigned long *)p, n)
327 #define pmap_pte_setbits(p, b) \
328 atomic_or_ulong((volatile unsigned long *)p, b)
329 #define pmap_pte_clearbits(p, b) \
330 atomic_and_ulong((volatile unsigned long *)p, ~(b))
331 #define pmap_pte_flush() /* nothing */
333 static __inline pt_entry_t
334 pmap_pa2pte(paddr_t pa
)
336 return (pt_entry_t
)xpmap_ptom_masked(pa
);
339 static __inline paddr_t
340 pmap_pte2pa(pt_entry_t pte
)
342 return xpmap_mtop_masked(pte
& PG_FRAME
);
345 pmap_pte_set(pt_entry_t
*pte
, pt_entry_t npte
)
348 xpq_queue_pte_update(xpmap_ptetomach(pte
), npte
);
352 static __inline pt_entry_t
353 pmap_pte_cas(volatile pt_entry_t
*ptep
, pt_entry_t o
, pt_entry_t n
)
356 pt_entry_t opte
= *ptep
;
359 xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(ptep
)), n
);
366 static __inline pt_entry_t
367 pmap_pte_testset(volatile pt_entry_t
*pte
, pt_entry_t npte
)
370 pt_entry_t opte
= *pte
;
371 xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(pte
)),
379 pmap_pte_setbits(volatile pt_entry_t
*pte
, pt_entry_t bits
)
382 xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(pte
)), (*pte
) | bits
);
388 pmap_pte_clearbits(volatile pt_entry_t
*pte
, pt_entry_t bits
)
391 xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(pte
)),
408 /* addresses of static pages used for PAE pmap: */
410 pd_entry_t
*pmap_l3pd
;
411 paddr_t pmap_l3paddr
;
412 /* the kernel's L2 page */
413 pd_entry_t
*pmap_kl2pd
;
414 paddr_t pmap_kl2paddr
;
420 int pmap_exec_fixup(struct vm_map
*, struct trapframe
*, struct pcb
*);
421 void pmap_ldt_cleanup(struct lwp
*);
423 #endif /* _I386_PMAP_H_ */