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 Clear the 'modified' bit on the given physical page
157 * @param _pg physical page
159 METHOD void clear_modify {
166 * @brief Clear the write and modified bits in each of the given
167 * physical page's mappings
169 * @param _pg physical page
171 METHOD void remove_write {
178 * @brief Copy the address range given by the source physical map, virtual
179 * address and length to the destination physical map and virtual address.
180 * This routine is optional (xxx default null implementation ?)
182 * @param _dst_pmap destination physical map
183 * @param _src_pmap source physical map
184 * @param _dst_addr destination virtual address
185 * @param _len size of range
186 * @param _src_addr source virtual address
192 vm_offset_t _dst_addr;
194 vm_offset_t _src_addr;
195 } DEFAULT mmu_null_copy;
199 * @brief Copy the source physical page to the destination physical page
201 * @param _src source physical page
202 * @param _dst destination physical page
204 METHOD void copy_page {
210 METHOD void copy_pages {
213 vm_offset_t _a_offset;
215 vm_offset_t _b_offset;
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 _flags pmap_enter flags
228 * @param _psind superpage size index
242 * @brief Maps a sequence of resident pages belonging to the same object.
244 * @param _pmap physical map
245 * @param _start virtual range start
246 * @param _end virtual range end
247 * @param _m_start physical page mapped at start
248 * @param _prot mapping page protection
250 METHOD void enter_object {
261 * @brief A faster entry point for page mapping where it is possible
262 * to short-circuit some of the tests in pmap_enter.
264 * @param _pmap physical map (and also currently active pmap)
265 * @param _va mapping virtual address
266 * @param _pg mapping physical page
267 * @param _prot new page protection - used to see if page is exec.
269 METHOD void enter_quick {
279 * @brief Reverse map the given virtual address, returning the physical
280 * page associated with the address if a mapping exists.
282 * @param _pmap physical map
283 * @param _va mapping virtual address
285 * @retval 0 No mapping found
286 * @retval addr The mapping physical address
288 METHOD vm_paddr_t extract {
296 * @brief Reverse map the given virtual address, returning the
297 * physical page if found. The page must be held (by calling
298 * vm_page_hold) if the page protection matches the given protection
300 * @param _pmap physical map
301 * @param _va mapping virtual address
302 * @param _prot protection used to determine if physical page
305 * @retval NULL No mapping found
306 * @retval page Pointer to physical page. Held if protections match
308 METHOD vm_page_t extract_and_hold {
317 * @brief Increase kernel virtual address space to the given virtual address.
318 * Not really required for PowerPC, so optional unless the MMU implementation
321 * @param _va new upper limit for kernel virtual address space
323 METHOD void growkernel {
326 } DEFAULT mmu_null_growkernel;
330 * @brief Called from vm_mem_init. Zone allocation is available at
331 * this stage so a convenient time to create zones. This routine is
332 * for MMU-implementation convenience and is optional.
336 } DEFAULT mmu_null_init;
340 * @brief Return if the page has been marked by MMU hardware to have been
343 * @param _pg physical page to test
345 * @retval boolean TRUE if page has been modified
347 METHOD boolean_t is_modified {
354 * @brief Return whether the specified virtual address is a candidate to be
355 * prefaulted in. This routine is optional.
357 * @param _pmap physical map
358 * @param _va virtual address to test
360 * @retval boolean TRUE if the address is a candidate.
362 METHOD boolean_t is_prefaultable {
366 } DEFAULT mmu_null_is_prefaultable;
370 * @brief Return whether or not the specified physical page was referenced
371 * in any physical maps.
373 * @params _pg physical page
375 * @retval boolean TRUE if page has been referenced
377 METHOD boolean_t is_referenced {
384 * @brief Return a count of referenced bits for a page, clearing those bits.
385 * Not all referenced bits need to be cleared, but it is necessary that 0
386 * only be returned when there are none set.
388 * @params _m physical page
390 * @retval int count of referenced bits
392 METHOD int ts_referenced {
399 * @brief Map the requested physical address range into kernel virtual
400 * address space. The value in _virt is taken as a hint. The virtual
401 * address of the range is returned, or NULL if the mapping could not
402 * be created. The range can be direct-mapped if that is supported.
404 * @param *_virt Hint for start virtual address, and also return
406 * @param _start physical address range start
407 * @param _end physical address range end
408 * @param _prot protection of range (currently ignored)
410 * @retval NULL could not map the area
411 * @retval addr, *_virt mapping start virtual address
413 METHOD vm_offset_t map {
423 * @brief Used to create a contiguous set of read-only mappings for a
424 * given object to try and eliminate a cascade of on-demand faults as
425 * the object is accessed sequentially. This routine is optional.
427 * @param _pmap physical map
428 * @param _addr mapping start virtual address
429 * @param _object device-backed V.M. object to be mapped
430 * @param _pindex page-index within object of mapping start
431 * @param _size size in bytes of mapping
433 METHOD void object_init_pt {
440 } DEFAULT mmu_null_object_init_pt;
444 * @brief Used to determine if the specified page has a mapping for the
445 * given physical map, by scanning the list of reverse-mappings from the
446 * page. The list is scanned to a maximum of 16 entries.
448 * @param _pmap physical map
449 * @param _pg physical page
451 * @retval bool TRUE if the physical map was found in the first 16
452 * reverse-map list entries off the physical page.
454 METHOD boolean_t page_exists_quick {
462 * @brief Initialise the machine-dependent section of the physical page
463 * data structure. This routine is optional.
465 * @param _pg physical page
467 METHOD void page_init {
470 } DEFAULT mmu_null_page_init;
474 * @brief Count the number of managed mappings to the given physical
475 * page that are wired.
477 * @param _pg physical page
479 * @retval int the number of wired, managed mappings to the
480 * given physical page
482 METHOD int page_wired_mappings {
489 * @brief Initialise a physical map data structure
491 * @param _pmap physical map
500 * @brief Initialise the physical map for process 0, the initial process
502 * XXX default to pinit ?
504 * @param _pmap physical map
513 * @brief Set the protection for physical pages in the given virtual address
514 * range to the given value.
516 * @param _pmap physical map
517 * @param _start virtual range start
518 * @param _end virtual range end
519 * @param _prot new page protection
521 METHOD void protect {
531 * @brief Create a mapping in kernel virtual address space for the given array
532 * of wired physical pages.
534 * @param _start mapping virtual address start
535 * @param *_m array of physical page pointers
536 * @param _count array elements
547 * @brief Remove the temporary mappings created by qenter.
549 * @param _start mapping virtual address start
550 * @param _count number of pages in mapping
552 METHOD void qremove {
560 * @brief Release per-pmap resources, e.g. mutexes, allocated memory etc. There
561 * should be no existing mappings for the physical map at this point
563 * @param _pmap physical map
565 METHOD void release {
572 * @brief Remove all mappings in the given physical map for the start/end
573 * virtual address range. The range will be page-aligned.
575 * @param _pmap physical map
576 * @param _start mapping virtual address start
577 * @param _end mapping virtual address end
588 * @brief Traverse the reverse-map list off the given physical page and
589 * remove all mappings. Clear the PGA_WRITEABLE attribute from the page.
591 * @param _pg physical page
593 METHOD void remove_all {
600 * @brief Remove all mappings in the given start/end virtual address range
601 * for the given physical map. Similar to the remove method, but it used
602 * when tearing down all mappings in an address space. This method is
603 * optional, since pmap_remove will be called for each valid vm_map in
604 * the address space later.
606 * @param _pmap physical map
607 * @param _start mapping virtual address start
608 * @param _end mapping virtual address end
610 METHOD void remove_pages {
613 } DEFAULT mmu_null_remove_pages;
617 * @brief Clear the wired attribute from the mappings for the specified range
618 * of addresses in the given pmap.
620 * @param _pmap physical map
621 * @param _start virtual range start
622 * @param _end virtual range end
633 * @brief Zero a physical page. It is not assumed that the page is mapped,
634 * so a temporary (or direct) mapping may need to be used.
636 * @param _pg physical page
638 METHOD void zero_page {
645 * @brief Zero a portion of a physical page, starting at a given offset and
646 * for a given size (multiples of 512 bytes for 4k pages).
648 * @param _pg physical page
649 * @param _off byte offset from start of page
650 * @param _size size of area to zero
652 METHOD void zero_page_area {
661 * @brief Called from the idle loop to zero pages. XXX I think locking
662 * constraints might be different here compared to zero_page.
664 * @param _pg physical page
666 METHOD void zero_page_idle {
673 * @brief Extract mincore(2) information from a mapping.
675 * @param _pmap physical map
676 * @param _addr page virtual address
677 * @param _locked_pa page physical address
679 * @retval 0 no result
680 * @retval non-zero mincore(2) flag values
686 vm_paddr_t *_locked_pa;
687 } DEFAULT mmu_null_mincore;
691 * @brief Perform any operations required to allow a physical map to be used
692 * before it's address space is accessed.
694 * @param _td thread associated with physical map
696 METHOD void activate {
702 * @brief Perform any operations required to deactivate a physical map,
703 * for instance as it is context-switched out.
705 * @param _td thread associated with physical map
707 METHOD void deactivate {
710 } DEFAULT mmu_null_deactivate;
713 * @brief Return a hint for the best virtual address to map a tentative
714 * virtual address range in a given VM object. The default is to just
715 * return the given tentative start address.
717 * @param _obj VM backing object
718 * @param _offset starting offset with the VM object
719 * @param _addr initial guess at virtual address
720 * @param _size size of virtual address range
722 METHOD void align_superpage {
725 vm_ooffset_t _offset;
728 } DEFAULT mmu_null_align_superpage;
734 * INTERNAL INTERFACES
738 * @brief Bootstrap the VM system. At the completion of this routine, the
739 * kernel will be running in it's own address space with full control over
742 * @param _start start of reserved memory (obsolete ???)
743 * @param _end end of reserved memory (obsolete ???)
744 * XXX I think the intent of these was to allow
745 * the memory used by kernel text+data+bss and
746 * loader variables/load-time kld's to be carved out
747 * of available physical mem.
750 METHOD void bootstrap {
757 * @brief Set up the MMU on the current CPU. Only called by the PMAP layer
758 * for alternate CPUs on SMP systems.
760 * @param _ap Set to 1 if the CPU being set up is an AP
763 METHOD void cpu_bootstrap {
770 * @brief Create a kernel mapping for a given physical address range.
771 * Called by bus code on behalf of device drivers. The mapping does not
772 * have to be a virtual address: it can be a direct-mapped physical address
773 * if that is supported by the MMU.
775 * @param _pa start physical address
776 * @param _size size in bytes of mapping
778 * @retval addr address of mapping.
780 METHOD void * mapdev {
787 * @brief Create a kernel mapping for a given physical address range.
788 * Called by bus code on behalf of device drivers. The mapping does not
789 * have to be a virtual address: it can be a direct-mapped physical address
790 * if that is supported by the MMU.
792 * @param _pa start physical address
793 * @param _size size in bytes of mapping
794 * @param _attr cache attributes
796 * @retval addr address of mapping.
798 METHOD void * mapdev_attr {
803 } DEFAULT mmu_null_mapdev_attr;
806 * @brief Change cache control attributes for a page. Should modify all
807 * mappings for that page.
809 * @param _m page to modify
810 * @param _ma new cache control attributes
812 METHOD void page_set_memattr {
816 } DEFAULT mmu_null_page_set_memattr;
819 * @brief Remove the mapping created by mapdev. Called when a driver
822 * @param _va Mapping address returned from mapdev
823 * @param _size size in bytes of mapping
825 METHOD void unmapdev {
833 * @brief Reverse-map a kernel virtual address
835 * @param _va kernel virtual address to reverse-map
837 * @retval pa physical address corresponding to mapping
839 METHOD vm_paddr_t kextract {
846 * @brief Map a wired page into kernel virtual address space
848 * @param _va mapping virtual address
849 * @param _pa mapping physical address
858 * @brief Map a wired page into kernel virtual address space
860 * @param _va mapping virtual address
861 * @param _pa mapping physical address
862 * @param _ma mapping cache control attributes
864 METHOD void kenter_attr {
869 } DEFAULT mmu_null_kenter_attr;
872 * @brief Determine if the given physical address range has been direct-mapped.
874 * @param _pa physical address start
875 * @param _size physical address range size
877 * @retval bool TRUE if the range is direct-mapped.
879 METHOD boolean_t dev_direct_mapped {
887 * @brief Enforce instruction cache coherency. Typically called after a
888 * region of memory has been modified and before execution of or within
889 * that region is attempted. Setting breakpoints in a process through
890 * ptrace(2) is one example of when the instruction cache needs to be
893 * @param _pm the physical map of the virtual address
894 * @param _va the virtual address of the modified region
895 * @param _sz the size of the modified region
897 METHOD void sync_icache {
906 * @brief Create temporary memory mapping for use by dumpsys().
908 * @param _md The memory chunk in which the mapping lies.
909 * @param _ofs The offset within the chunk of the mapping.
910 * @param _sz The requested size of the mapping.
912 * @retval vm_offset_t The virtual address of the mapping.
914 * The sz argument is modified to reflect the actual size of the
917 METHOD vm_offset_t dumpsys_map {
926 * @brief Remove temporary dumpsys() mapping.
928 * @param _md The memory chunk in which the mapping lies.
929 * @param _ofs The offset within the chunk of the mapping.
930 * @param _va The virtual address of the mapping.
932 METHOD void dumpsys_unmap {
941 * @brief Scan/iterate memory chunks.
943 * @param _prev The previously returned chunk or NULL.
945 * @retval The next (or first when _prev is NULL) chunk.
947 METHOD struct pmap_md * scan_md {
949 struct pmap_md *_prev;
950 } DEFAULT mmu_null_scan_md;