2 # Copyright (c) 2005 Peter Grehan
5 # Redistribution and use in source and binary forms, with or without
6 # modification, are permitted provided that the following conditions
8 # 1. Redistributions of source code must retain the above copyright
9 # notice, this list of conditions and the following disclaimer.
10 # 2. Redistributions in binary form must reproduce the above copyright
11 # notice, this list of conditions and the following disclaimer in the
12 # documentation and/or other materials provided with the distribution.
14 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 # ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/param.h>
31 #include <sys/mutex.h>
32 #include <sys/systm.h>
35 #include <vm/vm_page.h>
37 #include <machine/mmuvar.h>
40 * @defgroup MMU mmu - KObj methods for PowerPC MMU implementations
41 * @brief A set of methods required by all MMU implementations. These
42 * are basically direct call-thru's from the pmap machine-dependent
44 * Thanks to Bruce M Simpson's pmap man pages for routine descriptions.
51 # Default implementations of some methods
54 static void mmu_null_copy(mmu_t mmu, pmap_t dst_pmap, pmap_t src_pmap,
55 vm_offset_t dst_addr, vm_size_t len, vm_offset_t src_addr)
60 static void mmu_null_growkernel(mmu_t mmu, vm_offset_t addr)
65 static void mmu_null_init(mmu_t mmu)
70 static boolean_t mmu_null_is_prefaultable(mmu_t mmu, pmap_t pmap,
76 static void mmu_null_object_init_pt(mmu_t mmu, pmap_t pmap,
77 vm_offset_t addr, vm_object_t object, vm_pindex_t index,
83 static void mmu_null_page_init(mmu_t mmu, vm_page_t m)
88 static void mmu_null_remove_pages(mmu_t mmu, pmap_t pmap)
93 static int mmu_null_mincore(mmu_t mmu, pmap_t pmap, vm_offset_t addr,
94 vm_paddr_t *locked_pa)
99 static void mmu_null_deactivate(struct thread *td)
104 static void mmu_null_align_superpage(mmu_t mmu, vm_object_t object,
105 vm_ooffset_t offset, vm_offset_t *addr, vm_size_t size)
110 static struct pmap_md *mmu_null_scan_md(mmu_t mmu, struct pmap_md *p)
115 static void *mmu_null_mapdev_attr(mmu_t mmu, vm_offset_t pa,
116 vm_size_t size, vm_memattr_t ma)
118 return MMU_MAPDEV(mmu, pa, size);
121 static void mmu_null_kenter_attr(mmu_t mmu, vm_offset_t va,
122 vm_offset_t pa, vm_memattr_t ma)
124 MMU_KENTER(mmu, va, pa);
127 static void mmu_null_page_set_memattr(mmu_t mmu, vm_page_t m,
136 * @brief Change the wiring attribute for the page in the given physical
137 * map and virtual address.
139 * @param _pmap physical map of page
140 * @param _va page virtual address
141 * @param _wired TRUE to increment wired count, FALSE to decrement
143 METHOD void change_wiring {
152 * @brief Clear the 'modified' bit on the given physical page
154 * @param _pg physical page
156 METHOD void clear_modify {
163 * @brief Clear the 'referenced' bit on the given physical page
165 * @param _pg physical page
167 METHOD void clear_reference {
174 * @brief Clear the write and modified bits in each of the given
175 * physical page's mappings
177 * @param _pg physical page
179 METHOD void remove_write {
186 * @brief Copy the address range given by the source physical map, virtual
187 * address and length to the destination physical map and virtual address.
188 * This routine is optional (xxx default null implementation ?)
190 * @param _dst_pmap destination physical map
191 * @param _src_pmap source physical map
192 * @param _dst_addr destination virtual address
193 * @param _len size of range
194 * @param _src_addr source virtual address
200 vm_offset_t _dst_addr;
202 vm_offset_t _src_addr;
203 } DEFAULT mmu_null_copy;
207 * @brief Copy the source physical page to the destination physical page
209 * @param _src source physical page
210 * @param _dst destination physical page
212 METHOD void copy_page {
218 METHOD void copy_pages {
221 vm_offset_t _a_offset;
223 vm_offset_t _b_offset;
228 * @brief Create a mapping between a virtual/physical address pair in the
229 * passed physical map with the specified protection and wiring
231 * @param _pmap physical map
232 * @param _va mapping virtual address
233 * @param _p mapping physical page
234 * @param _prot mapping page protection
235 * @param _wired TRUE if page will be wired
248 * @brief Maps a sequence of resident pages belonging to the same object.
250 * @param _pmap physical map
251 * @param _start virtual range start
252 * @param _end virtual range end
253 * @param _m_start physical page mapped at start
254 * @param _prot mapping page protection
256 METHOD void enter_object {
267 * @brief A faster entry point for page mapping where it is possible
268 * to short-circuit some of the tests in pmap_enter.
270 * @param _pmap physical map (and also currently active pmap)
271 * @param _va mapping virtual address
272 * @param _pg mapping physical page
273 * @param _prot new page protection - used to see if page is exec.
275 METHOD void enter_quick {
285 * @brief Reverse map the given virtual address, returning the physical
286 * page associated with the address if a mapping exists.
288 * @param _pmap physical map
289 * @param _va mapping virtual address
291 * @retval 0 No mapping found
292 * @retval addr The mapping physical address
294 METHOD vm_paddr_t extract {
302 * @brief Reverse map the given virtual address, returning the
303 * physical page if found. The page must be held (by calling
304 * vm_page_hold) if the page protection matches the given protection
306 * @param _pmap physical map
307 * @param _va mapping virtual address
308 * @param _prot protection used to determine if physical page
311 * @retval NULL No mapping found
312 * @retval page Pointer to physical page. Held if protections match
314 METHOD vm_page_t extract_and_hold {
323 * @brief Increase kernel virtual address space to the given virtual address.
324 * Not really required for PowerPC, so optional unless the MMU implementation
327 * @param _va new upper limit for kernel virtual address space
329 METHOD void growkernel {
332 } DEFAULT mmu_null_growkernel;
336 * @brief Called from vm_mem_init. Zone allocation is available at
337 * this stage so a convenient time to create zones. This routine is
338 * for MMU-implementation convenience and is optional.
342 } DEFAULT mmu_null_init;
346 * @brief Return if the page has been marked by MMU hardware to have been
349 * @param _pg physical page to test
351 * @retval boolean TRUE if page has been modified
353 METHOD boolean_t is_modified {
360 * @brief Return whether the specified virtual address is a candidate to be
361 * prefaulted in. This routine is optional.
363 * @param _pmap physical map
364 * @param _va virtual address to test
366 * @retval boolean TRUE if the address is a candidate.
368 METHOD boolean_t is_prefaultable {
372 } DEFAULT mmu_null_is_prefaultable;
376 * @brief Return whether or not the specified physical page was referenced
377 * in any physical maps.
379 * @params _pg physical page
381 * @retval boolean TRUE if page has been referenced
383 METHOD boolean_t is_referenced {
390 * @brief Return a count of referenced bits for a page, clearing those bits.
391 * Not all referenced bits need to be cleared, but it is necessary that 0
392 * only be returned when there are none set.
394 * @params _m physical page
396 * @retval int count of referenced bits
398 METHOD boolean_t ts_referenced {
405 * @brief Map the requested physical address range into kernel virtual
406 * address space. The value in _virt is taken as a hint. The virtual
407 * address of the range is returned, or NULL if the mapping could not
408 * be created. The range can be direct-mapped if that is supported.
410 * @param *_virt Hint for start virtual address, and also return
412 * @param _start physical address range start
413 * @param _end physical address range end
414 * @param _prot protection of range (currently ignored)
416 * @retval NULL could not map the area
417 * @retval addr, *_virt mapping start virtual address
419 METHOD vm_offset_t map {
429 * @brief Used to create a contiguous set of read-only mappings for a
430 * given object to try and eliminate a cascade of on-demand faults as
431 * the object is accessed sequentially. This routine is optional.
433 * @param _pmap physical map
434 * @param _addr mapping start virtual address
435 * @param _object device-backed V.M. object to be mapped
436 * @param _pindex page-index within object of mapping start
437 * @param _size size in bytes of mapping
439 METHOD void object_init_pt {
446 } DEFAULT mmu_null_object_init_pt;
450 * @brief Used to determine if the specified page has a mapping for the
451 * given physical map, by scanning the list of reverse-mappings from the
452 * page. The list is scanned to a maximum of 16 entries.
454 * @param _pmap physical map
455 * @param _pg physical page
457 * @retval bool TRUE if the physical map was found in the first 16
458 * reverse-map list entries off the physical page.
460 METHOD boolean_t page_exists_quick {
468 * @brief Initialise the machine-dependent section of the physical page
469 * data structure. This routine is optional.
471 * @param _pg physical page
473 METHOD void page_init {
476 } DEFAULT mmu_null_page_init;
480 * @brief Count the number of managed mappings to the given physical
481 * page that are wired.
483 * @param _pg physical page
485 * @retval int the number of wired, managed mappings to the
486 * given physical page
488 METHOD int page_wired_mappings {
495 * @brief Initialise a physical map data structure
497 * @param _pmap physical map
506 * @brief Initialise the physical map for process 0, the initial process
508 * XXX default to pinit ?
510 * @param _pmap physical map
519 * @brief Set the protection for physical pages in the given virtual address
520 * range to the given value.
522 * @param _pmap physical map
523 * @param _start virtual range start
524 * @param _end virtual range end
525 * @param _prot new page protection
527 METHOD void protect {
537 * @brief Create a mapping in kernel virtual address space for the given array
538 * of wired physical pages.
540 * @param _start mapping virtual address start
541 * @param *_m array of physical page pointers
542 * @param _count array elements
553 * @brief Remove the temporary mappings created by qenter.
555 * @param _start mapping virtual address start
556 * @param _count number of pages in mapping
558 METHOD void qremove {
566 * @brief Release per-pmap resources, e.g. mutexes, allocated memory etc. There
567 * should be no existing mappings for the physical map at this point
569 * @param _pmap physical map
571 METHOD void release {
578 * @brief Remove all mappings in the given physical map for the start/end
579 * virtual address range. The range will be page-aligned.
581 * @param _pmap physical map
582 * @param _start mapping virtual address start
583 * @param _end mapping virtual address end
594 * @brief Traverse the reverse-map list off the given physical page and
595 * remove all mappings. Clear the PGA_WRITEABLE attribute from the page.
597 * @param _pg physical page
599 METHOD void remove_all {
606 * @brief Remove all mappings in the given start/end virtual address range
607 * for the given physical map. Similar to the remove method, but it used
608 * when tearing down all mappings in an address space. This method is
609 * optional, since pmap_remove will be called for each valid vm_map in
610 * the address space later.
612 * @param _pmap physical map
613 * @param _start mapping virtual address start
614 * @param _end mapping virtual address end
616 METHOD void remove_pages {
619 } DEFAULT mmu_null_remove_pages;
623 * @brief Zero a physical page. It is not assumed that the page is mapped,
624 * so a temporary (or direct) mapping may need to be used.
626 * @param _pg physical page
628 METHOD void zero_page {
635 * @brief Zero a portion of a physical page, starting at a given offset and
636 * for a given size (multiples of 512 bytes for 4k pages).
638 * @param _pg physical page
639 * @param _off byte offset from start of page
640 * @param _size size of area to zero
642 METHOD void zero_page_area {
651 * @brief Called from the idle loop to zero pages. XXX I think locking
652 * constraints might be different here compared to zero_page.
654 * @param _pg physical page
656 METHOD void zero_page_idle {
663 * @brief Extract mincore(2) information from a mapping.
665 * @param _pmap physical map
666 * @param _addr page virtual address
667 * @param _locked_pa page physical address
669 * @retval 0 no result
670 * @retval non-zero mincore(2) flag values
676 vm_paddr_t *_locked_pa;
677 } DEFAULT mmu_null_mincore;
681 * @brief Perform any operations required to allow a physical map to be used
682 * before it's address space is accessed.
684 * @param _td thread associated with physical map
686 METHOD void activate {
692 * @brief Perform any operations required to deactivate a physical map,
693 * for instance as it is context-switched out.
695 * @param _td thread associated with physical map
697 METHOD void deactivate {
700 } DEFAULT mmu_null_deactivate;
703 * @brief Return a hint for the best virtual address to map a tentative
704 * virtual address range in a given VM object. The default is to just
705 * return the given tentative start address.
707 * @param _obj VM backing object
708 * @param _offset starting offset with the VM object
709 * @param _addr initial guess at virtual address
710 * @param _size size of virtual address range
712 METHOD void align_superpage {
715 vm_ooffset_t _offset;
718 } DEFAULT mmu_null_align_superpage;
724 * INTERNAL INTERFACES
728 * @brief Bootstrap the VM system. At the completion of this routine, the
729 * kernel will be running in it's own address space with full control over
732 * @param _start start of reserved memory (obsolete ???)
733 * @param _end end of reserved memory (obsolete ???)
734 * XXX I think the intent of these was to allow
735 * the memory used by kernel text+data+bss and
736 * loader variables/load-time kld's to be carved out
737 * of available physical mem.
740 METHOD void bootstrap {
747 * @brief Set up the MMU on the current CPU. Only called by the PMAP layer
748 * for alternate CPUs on SMP systems.
750 * @param _ap Set to 1 if the CPU being set up is an AP
753 METHOD void cpu_bootstrap {
760 * @brief Create a kernel mapping for a given physical address range.
761 * Called by bus code on behalf of device drivers. The mapping does not
762 * have to be a virtual address: it can be a direct-mapped physical address
763 * if that is supported by the MMU.
765 * @param _pa start physical address
766 * @param _size size in bytes of mapping
768 * @retval addr address of mapping.
770 METHOD void * mapdev {
777 * @brief Create a kernel mapping for a given physical address range.
778 * Called by bus code on behalf of device drivers. The mapping does not
779 * have to be a virtual address: it can be a direct-mapped physical address
780 * if that is supported by the MMU.
782 * @param _pa start physical address
783 * @param _size size in bytes of mapping
784 * @param _attr cache attributes
786 * @retval addr address of mapping.
788 METHOD void * mapdev_attr {
793 } DEFAULT mmu_null_mapdev_attr;
796 * @brief Change cache control attributes for a page. Should modify all
797 * mappings for that page.
799 * @param _m page to modify
800 * @param _ma new cache control attributes
802 METHOD void page_set_memattr {
806 } DEFAULT mmu_null_page_set_memattr;
809 * @brief Remove the mapping created by mapdev. Called when a driver
812 * @param _va Mapping address returned from mapdev
813 * @param _size size in bytes of mapping
815 METHOD void unmapdev {
823 * @brief Reverse-map a kernel virtual address
825 * @param _va kernel virtual address to reverse-map
827 * @retval pa physical address corresponding to mapping
829 METHOD vm_offset_t kextract {
836 * @brief Map a wired page into kernel virtual address space
838 * @param _va mapping virtual address
839 * @param _pa mapping physical address
848 * @brief Map a wired page into kernel virtual address space
850 * @param _va mapping virtual address
851 * @param _pa mapping physical address
852 * @param _ma mapping cache control attributes
854 METHOD void kenter_attr {
859 } DEFAULT mmu_null_kenter_attr;
862 * @brief Determine if the given physical address range has been direct-mapped.
864 * @param _pa physical address start
865 * @param _size physical address range size
867 * @retval bool TRUE if the range is direct-mapped.
869 METHOD boolean_t dev_direct_mapped {
877 * @brief Enforce instruction cache coherency. Typically called after a
878 * region of memory has been modified and before execution of or within
879 * that region is attempted. Setting breakpoints in a process through
880 * ptrace(2) is one example of when the instruction cache needs to be
883 * @param _pm the physical map of the virtual address
884 * @param _va the virtual address of the modified region
885 * @param _sz the size of the modified region
887 METHOD void sync_icache {
896 * @brief Create temporary memory mapping for use by dumpsys().
898 * @param _md The memory chunk in which the mapping lies.
899 * @param _ofs The offset within the chunk of the mapping.
900 * @param _sz The requested size of the mapping.
902 * @retval vm_offset_t The virtual address of the mapping.
904 * The sz argument is modified to reflect the actual size of the
907 METHOD vm_offset_t dumpsys_map {
916 * @brief Remove temporary dumpsys() mapping.
918 * @param _md The memory chunk in which the mapping lies.
919 * @param _ofs The offset within the chunk of the mapping.
920 * @param _va The virtual address of the mapping.
922 METHOD void dumpsys_unmap {
931 * @brief Scan/iterate memory chunks.
933 * @param _prev The previously returned chunk or NULL.
935 * @retval The next (or first when _prev is NULL) chunk.
937 METHOD struct pmap_md * scan_md {
939 struct pmap_md *_prev;
940 } DEFAULT mmu_null_scan_md;