2 # Copyright (c) 2005 Peter Grehan
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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 Apply the given advice to the specified range of addresses within
137 * the given pmap. Depending on the advice, clear the referenced and/or
138 * modified flags in each mapping and set the mapped page's dirty field.
140 * @param _pmap physical map
141 * @param _start virtual range start
142 * @param _end virtual range end
143 * @param _advice advice to apply
155 * @brief Change the wiring attribute for the page in the given physical
156 * map and virtual address.
158 * @param _pmap physical map of page
159 * @param _va page virtual address
160 * @param _wired TRUE to increment wired count, FALSE to decrement
162 METHOD void change_wiring {
171 * @brief Clear the 'modified' bit on the given physical page
173 * @param _pg physical page
175 METHOD void clear_modify {
182 * @brief Clear the write and modified bits in each of the given
183 * physical page's mappings
185 * @param _pg physical page
187 METHOD void remove_write {
194 * @brief Copy the address range given by the source physical map, virtual
195 * address and length to the destination physical map and virtual address.
196 * This routine is optional (xxx default null implementation ?)
198 * @param _dst_pmap destination physical map
199 * @param _src_pmap source physical map
200 * @param _dst_addr destination virtual address
201 * @param _len size of range
202 * @param _src_addr source virtual address
208 vm_offset_t _dst_addr;
210 vm_offset_t _src_addr;
211 } DEFAULT mmu_null_copy;
215 * @brief Copy the source physical page to the destination physical page
217 * @param _src source physical page
218 * @param _dst destination physical page
220 METHOD void copy_page {
226 METHOD void copy_pages {
229 vm_offset_t _a_offset;
231 vm_offset_t _b_offset;
236 * @brief Create a mapping between a virtual/physical address pair in the
237 * passed physical map with the specified protection and wiring
239 * @param _pmap physical map
240 * @param _va mapping virtual address
241 * @param _p mapping physical page
242 * @param _prot mapping page protection
243 * @param _wired TRUE if page will be wired
256 * @brief Maps a sequence of resident pages belonging to the same object.
258 * @param _pmap physical map
259 * @param _start virtual range start
260 * @param _end virtual range end
261 * @param _m_start physical page mapped at start
262 * @param _prot mapping page protection
264 METHOD void enter_object {
275 * @brief A faster entry point for page mapping where it is possible
276 * to short-circuit some of the tests in pmap_enter.
278 * @param _pmap physical map (and also currently active pmap)
279 * @param _va mapping virtual address
280 * @param _pg mapping physical page
281 * @param _prot new page protection - used to see if page is exec.
283 METHOD void enter_quick {
293 * @brief Reverse map the given virtual address, returning the physical
294 * page associated with the address if a mapping exists.
296 * @param _pmap physical map
297 * @param _va mapping virtual address
299 * @retval 0 No mapping found
300 * @retval addr The mapping physical address
302 METHOD vm_paddr_t extract {
310 * @brief Reverse map the given virtual address, returning the
311 * physical page if found. The page must be held (by calling
312 * vm_page_hold) if the page protection matches the given protection
314 * @param _pmap physical map
315 * @param _va mapping virtual address
316 * @param _prot protection used to determine if physical page
319 * @retval NULL No mapping found
320 * @retval page Pointer to physical page. Held if protections match
322 METHOD vm_page_t extract_and_hold {
331 * @brief Increase kernel virtual address space to the given virtual address.
332 * Not really required for PowerPC, so optional unless the MMU implementation
335 * @param _va new upper limit for kernel virtual address space
337 METHOD void growkernel {
340 } DEFAULT mmu_null_growkernel;
344 * @brief Called from vm_mem_init. Zone allocation is available at
345 * this stage so a convenient time to create zones. This routine is
346 * for MMU-implementation convenience and is optional.
350 } DEFAULT mmu_null_init;
354 * @brief Return if the page has been marked by MMU hardware to have been
357 * @param _pg physical page to test
359 * @retval boolean TRUE if page has been modified
361 METHOD boolean_t is_modified {
368 * @brief Return whether the specified virtual address is a candidate to be
369 * prefaulted in. This routine is optional.
371 * @param _pmap physical map
372 * @param _va virtual address to test
374 * @retval boolean TRUE if the address is a candidate.
376 METHOD boolean_t is_prefaultable {
380 } DEFAULT mmu_null_is_prefaultable;
384 * @brief Return whether or not the specified physical page was referenced
385 * in any physical maps.
387 * @params _pg physical page
389 * @retval boolean TRUE if page has been referenced
391 METHOD boolean_t is_referenced {
398 * @brief Return a count of referenced bits for a page, clearing those bits.
399 * Not all referenced bits need to be cleared, but it is necessary that 0
400 * only be returned when there are none set.
402 * @params _m physical page
404 * @retval int count of referenced bits
406 METHOD int ts_referenced {
413 * @brief Map the requested physical address range into kernel virtual
414 * address space. The value in _virt is taken as a hint. The virtual
415 * address of the range is returned, or NULL if the mapping could not
416 * be created. The range can be direct-mapped if that is supported.
418 * @param *_virt Hint for start virtual address, and also return
420 * @param _start physical address range start
421 * @param _end physical address range end
422 * @param _prot protection of range (currently ignored)
424 * @retval NULL could not map the area
425 * @retval addr, *_virt mapping start virtual address
427 METHOD vm_offset_t map {
437 * @brief Used to create a contiguous set of read-only mappings for a
438 * given object to try and eliminate a cascade of on-demand faults as
439 * the object is accessed sequentially. This routine is optional.
441 * @param _pmap physical map
442 * @param _addr mapping start virtual address
443 * @param _object device-backed V.M. object to be mapped
444 * @param _pindex page-index within object of mapping start
445 * @param _size size in bytes of mapping
447 METHOD void object_init_pt {
454 } DEFAULT mmu_null_object_init_pt;
458 * @brief Used to determine if the specified page has a mapping for the
459 * given physical map, by scanning the list of reverse-mappings from the
460 * page. The list is scanned to a maximum of 16 entries.
462 * @param _pmap physical map
463 * @param _pg physical page
465 * @retval bool TRUE if the physical map was found in the first 16
466 * reverse-map list entries off the physical page.
468 METHOD boolean_t page_exists_quick {
476 * @brief Initialise the machine-dependent section of the physical page
477 * data structure. This routine is optional.
479 * @param _pg physical page
481 METHOD void page_init {
484 } DEFAULT mmu_null_page_init;
488 * @brief Count the number of managed mappings to the given physical
489 * page that are wired.
491 * @param _pg physical page
493 * @retval int the number of wired, managed mappings to the
494 * given physical page
496 METHOD int page_wired_mappings {
503 * @brief Initialise a physical map data structure
505 * @param _pmap physical map
514 * @brief Initialise the physical map for process 0, the initial process
516 * XXX default to pinit ?
518 * @param _pmap physical map
527 * @brief Set the protection for physical pages in the given virtual address
528 * range to the given value.
530 * @param _pmap physical map
531 * @param _start virtual range start
532 * @param _end virtual range end
533 * @param _prot new page protection
535 METHOD void protect {
545 * @brief Create a mapping in kernel virtual address space for the given array
546 * of wired physical pages.
548 * @param _start mapping virtual address start
549 * @param *_m array of physical page pointers
550 * @param _count array elements
561 * @brief Remove the temporary mappings created by qenter.
563 * @param _start mapping virtual address start
564 * @param _count number of pages in mapping
566 METHOD void qremove {
574 * @brief Release per-pmap resources, e.g. mutexes, allocated memory etc. There
575 * should be no existing mappings for the physical map at this point
577 * @param _pmap physical map
579 METHOD void release {
586 * @brief Remove all mappings in the given physical map for the start/end
587 * virtual address range. The range will be page-aligned.
589 * @param _pmap physical map
590 * @param _start mapping virtual address start
591 * @param _end mapping virtual address end
602 * @brief Traverse the reverse-map list off the given physical page and
603 * remove all mappings. Clear the PGA_WRITEABLE attribute from the page.
605 * @param _pg physical page
607 METHOD void remove_all {
614 * @brief Remove all mappings in the given start/end virtual address range
615 * for the given physical map. Similar to the remove method, but it used
616 * when tearing down all mappings in an address space. This method is
617 * optional, since pmap_remove will be called for each valid vm_map in
618 * the address space later.
620 * @param _pmap physical map
621 * @param _start mapping virtual address start
622 * @param _end mapping virtual address end
624 METHOD void remove_pages {
627 } DEFAULT mmu_null_remove_pages;
631 * @brief Clear the wired attribute from the mappings for the specified range
632 * of addresses in the given pmap.
634 * @param _pmap physical map
635 * @param _start virtual range start
636 * @param _end virtual range end
647 * @brief Zero a physical page. It is not assumed that the page is mapped,
648 * so a temporary (or direct) mapping may need to be used.
650 * @param _pg physical page
652 METHOD void zero_page {
659 * @brief Zero a portion of a physical page, starting at a given offset and
660 * for a given size (multiples of 512 bytes for 4k pages).
662 * @param _pg physical page
663 * @param _off byte offset from start of page
664 * @param _size size of area to zero
666 METHOD void zero_page_area {
675 * @brief Called from the idle loop to zero pages. XXX I think locking
676 * constraints might be different here compared to zero_page.
678 * @param _pg physical page
680 METHOD void zero_page_idle {
687 * @brief Extract mincore(2) information from a mapping.
689 * @param _pmap physical map
690 * @param _addr page virtual address
691 * @param _locked_pa page physical address
693 * @retval 0 no result
694 * @retval non-zero mincore(2) flag values
700 vm_paddr_t *_locked_pa;
701 } DEFAULT mmu_null_mincore;
705 * @brief Perform any operations required to allow a physical map to be used
706 * before it's address space is accessed.
708 * @param _td thread associated with physical map
710 METHOD void activate {
716 * @brief Perform any operations required to deactivate a physical map,
717 * for instance as it is context-switched out.
719 * @param _td thread associated with physical map
721 METHOD void deactivate {
724 } DEFAULT mmu_null_deactivate;
727 * @brief Return a hint for the best virtual address to map a tentative
728 * virtual address range in a given VM object. The default is to just
729 * return the given tentative start address.
731 * @param _obj VM backing object
732 * @param _offset starting offset with the VM object
733 * @param _addr initial guess at virtual address
734 * @param _size size of virtual address range
736 METHOD void align_superpage {
739 vm_ooffset_t _offset;
742 } DEFAULT mmu_null_align_superpage;
748 * INTERNAL INTERFACES
752 * @brief Bootstrap the VM system. At the completion of this routine, the
753 * kernel will be running in it's own address space with full control over
756 * @param _start start of reserved memory (obsolete ???)
757 * @param _end end of reserved memory (obsolete ???)
758 * XXX I think the intent of these was to allow
759 * the memory used by kernel text+data+bss and
760 * loader variables/load-time kld's to be carved out
761 * of available physical mem.
764 METHOD void bootstrap {
771 * @brief Set up the MMU on the current CPU. Only called by the PMAP layer
772 * for alternate CPUs on SMP systems.
774 * @param _ap Set to 1 if the CPU being set up is an AP
777 METHOD void cpu_bootstrap {
784 * @brief Create a kernel mapping for a given physical address range.
785 * Called by bus code on behalf of device drivers. The mapping does not
786 * have to be a virtual address: it can be a direct-mapped physical address
787 * if that is supported by the MMU.
789 * @param _pa start physical address
790 * @param _size size in bytes of mapping
792 * @retval addr address of mapping.
794 METHOD void * mapdev {
801 * @brief Create a kernel mapping for a given physical address range.
802 * Called by bus code on behalf of device drivers. The mapping does not
803 * have to be a virtual address: it can be a direct-mapped physical address
804 * if that is supported by the MMU.
806 * @param _pa start physical address
807 * @param _size size in bytes of mapping
808 * @param _attr cache attributes
810 * @retval addr address of mapping.
812 METHOD void * mapdev_attr {
817 } DEFAULT mmu_null_mapdev_attr;
820 * @brief Change cache control attributes for a page. Should modify all
821 * mappings for that page.
823 * @param _m page to modify
824 * @param _ma new cache control attributes
826 METHOD void page_set_memattr {
830 } DEFAULT mmu_null_page_set_memattr;
833 * @brief Remove the mapping created by mapdev. Called when a driver
836 * @param _va Mapping address returned from mapdev
837 * @param _size size in bytes of mapping
839 METHOD void unmapdev {
847 * @brief Reverse-map a kernel virtual address
849 * @param _va kernel virtual address to reverse-map
851 * @retval pa physical address corresponding to mapping
853 METHOD vm_paddr_t kextract {
860 * @brief Map a wired page into kernel virtual address space
862 * @param _va mapping virtual address
863 * @param _pa mapping physical address
872 * @brief Map a wired page into kernel virtual address space
874 * @param _va mapping virtual address
875 * @param _pa mapping physical address
876 * @param _ma mapping cache control attributes
878 METHOD void kenter_attr {
883 } DEFAULT mmu_null_kenter_attr;
886 * @brief Determine if the given physical address range has been direct-mapped.
888 * @param _pa physical address start
889 * @param _size physical address range size
891 * @retval bool TRUE if the range is direct-mapped.
893 METHOD boolean_t dev_direct_mapped {
901 * @brief Enforce instruction cache coherency. Typically called after a
902 * region of memory has been modified and before execution of or within
903 * that region is attempted. Setting breakpoints in a process through
904 * ptrace(2) is one example of when the instruction cache needs to be
907 * @param _pm the physical map of the virtual address
908 * @param _va the virtual address of the modified region
909 * @param _sz the size of the modified region
911 METHOD void sync_icache {
920 * @brief Create temporary memory mapping for use by dumpsys().
922 * @param _md The memory chunk in which the mapping lies.
923 * @param _ofs The offset within the chunk of the mapping.
924 * @param _sz The requested size of the mapping.
926 * @retval vm_offset_t The virtual address of the mapping.
928 * The sz argument is modified to reflect the actual size of the
931 METHOD vm_offset_t dumpsys_map {
940 * @brief Remove temporary dumpsys() mapping.
942 * @param _md The memory chunk in which the mapping lies.
943 * @param _ofs The offset within the chunk of the mapping.
944 * @param _va The virtual address of the mapping.
946 METHOD void dumpsys_unmap {
955 * @brief Scan/iterate memory chunks.
957 * @param _prev The previously returned chunk or NULL.
959 * @retval The next (or first when _prev is NULL) chunk.
961 METHOD struct pmap_md * scan_md {
963 struct pmap_md *_prev;
964 } DEFAULT mmu_null_scan_md;