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 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 {
220 * @brief Create a mapping between a virtual/physical address pair in the
221 * passed physical map with the specified protection and wiring
223 * @param _pmap physical map
224 * @param _va mapping virtual address
225 * @param _p mapping physical page
226 * @param _prot mapping page protection
227 * @param _wired TRUE if page will be wired
240 * @brief Maps a sequence of resident pages belonging to the same object.
242 * @param _pmap physical map
243 * @param _start virtual range start
244 * @param _end virtual range end
245 * @param _m_start physical page mapped at start
246 * @param _prot mapping page protection
248 METHOD void enter_object {
259 * @brief A faster entry point for page mapping where it is possible
260 * to short-circuit some of the tests in pmap_enter.
262 * @param _pmap physical map (and also currently active pmap)
263 * @param _va mapping virtual address
264 * @param _pg mapping physical page
265 * @param _prot new page protection - used to see if page is exec.
267 METHOD void enter_quick {
277 * @brief Reverse map the given virtual address, returning the physical
278 * page associated with the address if a mapping exists.
280 * @param _pmap physical map
281 * @param _va mapping virtual address
283 * @retval 0 No mapping found
284 * @retval addr The mapping physical address
286 METHOD vm_paddr_t extract {
294 * @brief Reverse map the given virtual address, returning the
295 * physical page if found. The page must be held (by calling
296 * vm_page_hold) if the page protection matches the given protection
298 * @param _pmap physical map
299 * @param _va mapping virtual address
300 * @param _prot protection used to determine if physical page
303 * @retval NULL No mapping found
304 * @retval page Pointer to physical page. Held if protections match
306 METHOD vm_page_t extract_and_hold {
315 * @brief Increase kernel virtual address space to the given virtual address.
316 * Not really required for PowerPC, so optional unless the MMU implementation
319 * @param _va new upper limit for kernel virtual address space
321 METHOD void growkernel {
324 } DEFAULT mmu_null_growkernel;
328 * @brief Called from vm_mem_init. Zone allocation is available at
329 * this stage so a convenient time to create zones. This routine is
330 * for MMU-implementation convenience and is optional.
334 } DEFAULT mmu_null_init;
338 * @brief Return if the page has been marked by MMU hardware to have been
341 * @param _pg physical page to test
343 * @retval boolean TRUE if page has been modified
345 METHOD boolean_t is_modified {
352 * @brief Return whether the specified virtual address is a candidate to be
353 * prefaulted in. This routine is optional.
355 * @param _pmap physical map
356 * @param _va virtual address to test
358 * @retval boolean TRUE if the address is a candidate.
360 METHOD boolean_t is_prefaultable {
364 } DEFAULT mmu_null_is_prefaultable;
368 * @brief Return whether or not the specified physical page was referenced
369 * in any physical maps.
371 * @params _pg physical page
373 * @retval boolean TRUE if page has been referenced
375 METHOD boolean_t is_referenced {
382 * @brief Return a count of referenced bits for a page, clearing those bits.
383 * Not all referenced bits need to be cleared, but it is necessary that 0
384 * only be returned when there are none set.
386 * @params _m physical page
388 * @retval int count of referenced bits
390 METHOD boolean_t ts_referenced {
397 * @brief Map the requested physical address range into kernel virtual
398 * address space. The value in _virt is taken as a hint. The virtual
399 * address of the range is returned, or NULL if the mapping could not
400 * be created. The range can be direct-mapped if that is supported.
402 * @param *_virt Hint for start virtual address, and also return
404 * @param _start physical address range start
405 * @param _end physical address range end
406 * @param _prot protection of range (currently ignored)
408 * @retval NULL could not map the area
409 * @retval addr, *_virt mapping start virtual address
411 METHOD vm_offset_t map {
421 * @brief Used to create a contiguous set of read-only mappings for a
422 * given object to try and eliminate a cascade of on-demand faults as
423 * the object is accessed sequentially. This routine is optional.
425 * @param _pmap physical map
426 * @param _addr mapping start virtual address
427 * @param _object device-backed V.M. object to be mapped
428 * @param _pindex page-index within object of mapping start
429 * @param _size size in bytes of mapping
431 METHOD void object_init_pt {
438 } DEFAULT mmu_null_object_init_pt;
442 * @brief Used to determine if the specified page has a mapping for the
443 * given physical map, by scanning the list of reverse-mappings from the
444 * page. The list is scanned to a maximum of 16 entries.
446 * @param _pmap physical map
447 * @param _pg physical page
449 * @retval bool TRUE if the physical map was found in the first 16
450 * reverse-map list entries off the physical page.
452 METHOD boolean_t page_exists_quick {
460 * @brief Initialise the machine-dependent section of the physical page
461 * data structure. This routine is optional.
463 * @param _pg physical page
465 METHOD void page_init {
468 } DEFAULT mmu_null_page_init;
472 * @brief Count the number of managed mappings to the given physical
473 * page that are wired.
475 * @param _pg physical page
477 * @retval int the number of wired, managed mappings to the
478 * given physical page
480 METHOD int page_wired_mappings {
487 * @brief Initialise a physical map data structure
489 * @param _pmap physical map
498 * @brief Initialise the physical map for process 0, the initial process
500 * XXX default to pinit ?
502 * @param _pmap physical map
511 * @brief Set the protection for physical pages in the given virtual address
512 * range to the given value.
514 * @param _pmap physical map
515 * @param _start virtual range start
516 * @param _end virtual range end
517 * @param _prot new page protection
519 METHOD void protect {
529 * @brief Create a mapping in kernel virtual address space for the given array
530 * of wired physical pages.
532 * @param _start mapping virtual address start
533 * @param *_m array of physical page pointers
534 * @param _count array elements
545 * @brief Remove the temporary mappings created by qenter.
547 * @param _start mapping virtual address start
548 * @param _count number of pages in mapping
550 METHOD void qremove {
558 * @brief Release per-pmap resources, e.g. mutexes, allocated memory etc. There
559 * should be no existing mappings for the physical map at this point
561 * @param _pmap physical map
563 METHOD void release {
570 * @brief Remove all mappings in the given physical map for the start/end
571 * virtual address range. The range will be page-aligned.
573 * @param _pmap physical map
574 * @param _start mapping virtual address start
575 * @param _end mapping virtual address end
586 * @brief Traverse the reverse-map list off the given physical page and
587 * remove all mappings. Clear the PGA_WRITEABLE attribute from the page.
589 * @param _pg physical page
591 METHOD void remove_all {
598 * @brief Remove all mappings in the given start/end virtual address range
599 * for the given physical map. Similar to the remove method, but it used
600 * when tearing down all mappings in an address space. This method is
601 * optional, since pmap_remove will be called for each valid vm_map in
602 * the address space later.
604 * @param _pmap physical map
605 * @param _start mapping virtual address start
606 * @param _end mapping virtual address end
608 METHOD void remove_pages {
611 } DEFAULT mmu_null_remove_pages;
615 * @brief Zero a physical page. It is not assumed that the page is mapped,
616 * so a temporary (or direct) mapping may need to be used.
618 * @param _pg physical page
620 METHOD void zero_page {
627 * @brief Zero a portion of a physical page, starting at a given offset and
628 * for a given size (multiples of 512 bytes for 4k pages).
630 * @param _pg physical page
631 * @param _off byte offset from start of page
632 * @param _size size of area to zero
634 METHOD void zero_page_area {
643 * @brief Called from the idle loop to zero pages. XXX I think locking
644 * constraints might be different here compared to zero_page.
646 * @param _pg physical page
648 METHOD void zero_page_idle {
655 * @brief Extract mincore(2) information from a mapping.
657 * @param _pmap physical map
658 * @param _addr page virtual address
659 * @param _locked_pa page physical address
661 * @retval 0 no result
662 * @retval non-zero mincore(2) flag values
668 vm_paddr_t *_locked_pa;
669 } DEFAULT mmu_null_mincore;
673 * @brief Perform any operations required to allow a physical map to be used
674 * before it's address space is accessed.
676 * @param _td thread associated with physical map
678 METHOD void activate {
684 * @brief Perform any operations required to deactivate a physical map,
685 * for instance as it is context-switched out.
687 * @param _td thread associated with physical map
689 METHOD void deactivate {
692 } DEFAULT mmu_null_deactivate;
695 * @brief Return a hint for the best virtual address to map a tentative
696 * virtual address range in a given VM object. The default is to just
697 * return the given tentative start address.
699 * @param _obj VM backing object
700 * @param _offset starting offset with the VM object
701 * @param _addr initial guess at virtual address
702 * @param _size size of virtual address range
704 METHOD void align_superpage {
707 vm_ooffset_t _offset;
710 } DEFAULT mmu_null_align_superpage;
716 * INTERNAL INTERFACES
720 * @brief Bootstrap the VM system. At the completion of this routine, the
721 * kernel will be running in it's own address space with full control over
724 * @param _start start of reserved memory (obsolete ???)
725 * @param _end end of reserved memory (obsolete ???)
726 * XXX I think the intent of these was to allow
727 * the memory used by kernel text+data+bss and
728 * loader variables/load-time kld's to be carved out
729 * of available physical mem.
732 METHOD void bootstrap {
739 * @brief Set up the MMU on the current CPU. Only called by the PMAP layer
740 * for alternate CPUs on SMP systems.
742 * @param _ap Set to 1 if the CPU being set up is an AP
745 METHOD void cpu_bootstrap {
752 * @brief Create a kernel mapping for a given physical address range.
753 * Called by bus code on behalf of device drivers. The mapping does not
754 * have to be a virtual address: it can be a direct-mapped physical address
755 * if that is supported by the MMU.
757 * @param _pa start physical address
758 * @param _size size in bytes of mapping
760 * @retval addr address of mapping.
762 METHOD void * mapdev {
769 * @brief Create a kernel mapping for a given physical address range.
770 * Called by bus code on behalf of device drivers. The mapping does not
771 * have to be a virtual address: it can be a direct-mapped physical address
772 * if that is supported by the MMU.
774 * @param _pa start physical address
775 * @param _size size in bytes of mapping
776 * @param _attr cache attributes
778 * @retval addr address of mapping.
780 METHOD void * mapdev_attr {
785 } DEFAULT mmu_null_mapdev_attr;
788 * @brief Change cache control attributes for a page. Should modify all
789 * mappings for that page.
791 * @param _m page to modify
792 * @param _ma new cache control attributes
794 METHOD void page_set_memattr {
798 } DEFAULT mmu_null_page_set_memattr;
801 * @brief Remove the mapping created by mapdev. Called when a driver
804 * @param _va Mapping address returned from mapdev
805 * @param _size size in bytes of mapping
807 METHOD void unmapdev {
815 * @brief Reverse-map a kernel virtual address
817 * @param _va kernel virtual address to reverse-map
819 * @retval pa physical address corresponding to mapping
821 METHOD vm_offset_t kextract {
828 * @brief Map a wired page into kernel virtual address space
830 * @param _va mapping virtual address
831 * @param _pa mapping physical address
840 * @brief Map a wired page into kernel virtual address space
842 * @param _va mapping virtual address
843 * @param _pa mapping physical address
844 * @param _ma mapping cache control attributes
846 METHOD void kenter_attr {
851 } DEFAULT mmu_null_kenter_attr;
854 * @brief Determine if the given physical address range has been direct-mapped.
856 * @param _pa physical address start
857 * @param _size physical address range size
859 * @retval bool TRUE if the range is direct-mapped.
861 METHOD boolean_t dev_direct_mapped {
869 * @brief Enforce instruction cache coherency. Typically called after a
870 * region of memory has been modified and before execution of or within
871 * that region is attempted. Setting breakpoints in a process through
872 * ptrace(2) is one example of when the instruction cache needs to be
875 * @param _pm the physical map of the virtual address
876 * @param _va the virtual address of the modified region
877 * @param _sz the size of the modified region
879 METHOD void sync_icache {
888 * @brief Create temporary memory mapping for use by dumpsys().
890 * @param _md The memory chunk in which the mapping lies.
891 * @param _ofs The offset within the chunk of the mapping.
892 * @param _sz The requested size of the mapping.
894 * @retval vm_offset_t The virtual address of the mapping.
896 * The sz argument is modified to reflect the actual size of the
899 METHOD vm_offset_t dumpsys_map {
908 * @brief Remove temporary dumpsys() mapping.
910 * @param _md The memory chunk in which the mapping lies.
911 * @param _ofs The offset within the chunk of the mapping.
912 * @param _va The virtual address of the mapping.
914 METHOD void dumpsys_unmap {
923 * @brief Scan/iterate memory chunks.
925 * @param _prev The previously returned chunk or NULL.
927 * @retval The next (or first when _prev is NULL) chunk.
929 METHOD struct pmap_md * scan_md {
931 struct pmap_md *_prev;
932 } DEFAULT mmu_null_scan_md;