x86/efi: Enforce CONFIG_RELOCATABLE for EFI boot stub
[linux/fpc-iii.git] / arch / powerpc / mm / pgtable_64.c
blob536eec72c0f701584b717b86189d039442c54acb
1 /*
2 * This file contains ioremap and related functions for 64-bit machines.
4 * Derived from arch/ppc64/mm/init.c
5 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
7 * Modifications by Paul Mackerras (PowerMac) (paulus@samba.org)
8 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
9 * Copyright (C) 1996 Paul Mackerras
11 * Derived from "arch/i386/mm/init.c"
12 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
14 * Dave Engebretsen <engebret@us.ibm.com>
15 * Rework for PPC64 port.
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License
19 * as published by the Free Software Foundation; either version
20 * 2 of the License, or (at your option) any later version.
24 #include <linux/signal.h>
25 #include <linux/sched.h>
26 #include <linux/kernel.h>
27 #include <linux/errno.h>
28 #include <linux/string.h>
29 #include <linux/export.h>
30 #include <linux/types.h>
31 #include <linux/mman.h>
32 #include <linux/mm.h>
33 #include <linux/swap.h>
34 #include <linux/stddef.h>
35 #include <linux/vmalloc.h>
36 #include <linux/init.h>
37 #include <linux/bootmem.h>
38 #include <linux/memblock.h>
39 #include <linux/slab.h>
41 #include <asm/pgalloc.h>
42 #include <asm/page.h>
43 #include <asm/prom.h>
44 #include <asm/io.h>
45 #include <asm/mmu_context.h>
46 #include <asm/pgtable.h>
47 #include <asm/mmu.h>
48 #include <asm/smp.h>
49 #include <asm/machdep.h>
50 #include <asm/tlb.h>
51 #include <asm/processor.h>
52 #include <asm/cputable.h>
53 #include <asm/sections.h>
54 #include <asm/firmware.h>
56 #include "mmu_decl.h"
58 /* Some sanity checking */
59 #if TASK_SIZE_USER64 > PGTABLE_RANGE
60 #error TASK_SIZE_USER64 exceeds pagetable range
61 #endif
63 #ifdef CONFIG_PPC_STD_MMU_64
64 #if TASK_SIZE_USER64 > (1UL << (ESID_BITS + SID_SHIFT))
65 #error TASK_SIZE_USER64 exceeds user VSID range
66 #endif
67 #endif
69 unsigned long ioremap_bot = IOREMAP_BASE;
71 #ifdef CONFIG_PPC_MMU_NOHASH
72 static void *early_alloc_pgtable(unsigned long size)
74 void *pt;
76 if (init_bootmem_done)
77 pt = __alloc_bootmem(size, size, __pa(MAX_DMA_ADDRESS));
78 else
79 pt = __va(memblock_alloc_base(size, size,
80 __pa(MAX_DMA_ADDRESS)));
81 memset(pt, 0, size);
83 return pt;
85 #endif /* CONFIG_PPC_MMU_NOHASH */
88 * map_kernel_page currently only called by __ioremap
89 * map_kernel_page adds an entry to the ioremap page table
90 * and adds an entry to the HPT, possibly bolting it
92 int map_kernel_page(unsigned long ea, unsigned long pa, int flags)
94 pgd_t *pgdp;
95 pud_t *pudp;
96 pmd_t *pmdp;
97 pte_t *ptep;
99 if (slab_is_available()) {
100 pgdp = pgd_offset_k(ea);
101 pudp = pud_alloc(&init_mm, pgdp, ea);
102 if (!pudp)
103 return -ENOMEM;
104 pmdp = pmd_alloc(&init_mm, pudp, ea);
105 if (!pmdp)
106 return -ENOMEM;
107 ptep = pte_alloc_kernel(pmdp, ea);
108 if (!ptep)
109 return -ENOMEM;
110 set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
111 __pgprot(flags)));
112 } else {
113 #ifdef CONFIG_PPC_MMU_NOHASH
114 /* Warning ! This will blow up if bootmem is not initialized
115 * which our ppc64 code is keen to do that, we'll need to
116 * fix it and/or be more careful
118 pgdp = pgd_offset_k(ea);
119 #ifdef PUD_TABLE_SIZE
120 if (pgd_none(*pgdp)) {
121 pudp = early_alloc_pgtable(PUD_TABLE_SIZE);
122 BUG_ON(pudp == NULL);
123 pgd_populate(&init_mm, pgdp, pudp);
125 #endif /* PUD_TABLE_SIZE */
126 pudp = pud_offset(pgdp, ea);
127 if (pud_none(*pudp)) {
128 pmdp = early_alloc_pgtable(PMD_TABLE_SIZE);
129 BUG_ON(pmdp == NULL);
130 pud_populate(&init_mm, pudp, pmdp);
132 pmdp = pmd_offset(pudp, ea);
133 if (!pmd_present(*pmdp)) {
134 ptep = early_alloc_pgtable(PAGE_SIZE);
135 BUG_ON(ptep == NULL);
136 pmd_populate_kernel(&init_mm, pmdp, ptep);
138 ptep = pte_offset_kernel(pmdp, ea);
139 set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
140 __pgprot(flags)));
141 #else /* CONFIG_PPC_MMU_NOHASH */
143 * If the mm subsystem is not fully up, we cannot create a
144 * linux page table entry for this mapping. Simply bolt an
145 * entry in the hardware page table.
148 if (htab_bolt_mapping(ea, ea + PAGE_SIZE, pa, flags,
149 mmu_io_psize, mmu_kernel_ssize)) {
150 printk(KERN_ERR "Failed to do bolted mapping IO "
151 "memory at %016lx !\n", pa);
152 return -ENOMEM;
154 #endif /* !CONFIG_PPC_MMU_NOHASH */
156 return 0;
161 * __ioremap_at - Low level function to establish the page tables
162 * for an IO mapping
164 void __iomem * __ioremap_at(phys_addr_t pa, void *ea, unsigned long size,
165 unsigned long flags)
167 unsigned long i;
169 /* Make sure we have the base flags */
170 if ((flags & _PAGE_PRESENT) == 0)
171 flags |= pgprot_val(PAGE_KERNEL);
173 /* Non-cacheable page cannot be coherent */
174 if (flags & _PAGE_NO_CACHE)
175 flags &= ~_PAGE_COHERENT;
177 /* We don't support the 4K PFN hack with ioremap */
178 if (flags & _PAGE_4K_PFN)
179 return NULL;
181 WARN_ON(pa & ~PAGE_MASK);
182 WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
183 WARN_ON(size & ~PAGE_MASK);
185 for (i = 0; i < size; i += PAGE_SIZE)
186 if (map_kernel_page((unsigned long)ea+i, pa+i, flags))
187 return NULL;
189 return (void __iomem *)ea;
193 * __iounmap_from - Low level function to tear down the page tables
194 * for an IO mapping. This is used for mappings that
195 * are manipulated manually, like partial unmapping of
196 * PCI IOs or ISA space.
198 void __iounmap_at(void *ea, unsigned long size)
200 WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
201 WARN_ON(size & ~PAGE_MASK);
203 unmap_kernel_range((unsigned long)ea, size);
206 void __iomem * __ioremap_caller(phys_addr_t addr, unsigned long size,
207 unsigned long flags, void *caller)
209 phys_addr_t paligned;
210 void __iomem *ret;
213 * Choose an address to map it to.
214 * Once the imalloc system is running, we use it.
215 * Before that, we map using addresses going
216 * up from ioremap_bot. imalloc will use
217 * the addresses from ioremap_bot through
218 * IMALLOC_END
221 paligned = addr & PAGE_MASK;
222 size = PAGE_ALIGN(addr + size) - paligned;
224 if ((size == 0) || (paligned == 0))
225 return NULL;
227 if (mem_init_done) {
228 struct vm_struct *area;
230 area = __get_vm_area_caller(size, VM_IOREMAP,
231 ioremap_bot, IOREMAP_END,
232 caller);
233 if (area == NULL)
234 return NULL;
236 area->phys_addr = paligned;
237 ret = __ioremap_at(paligned, area->addr, size, flags);
238 if (!ret)
239 vunmap(area->addr);
240 } else {
241 ret = __ioremap_at(paligned, (void *)ioremap_bot, size, flags);
242 if (ret)
243 ioremap_bot += size;
246 if (ret)
247 ret += addr & ~PAGE_MASK;
248 return ret;
251 void __iomem * __ioremap(phys_addr_t addr, unsigned long size,
252 unsigned long flags)
254 return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
257 void __iomem * ioremap(phys_addr_t addr, unsigned long size)
259 unsigned long flags = _PAGE_NO_CACHE | _PAGE_GUARDED;
260 void *caller = __builtin_return_address(0);
262 if (ppc_md.ioremap)
263 return ppc_md.ioremap(addr, size, flags, caller);
264 return __ioremap_caller(addr, size, flags, caller);
267 void __iomem * ioremap_wc(phys_addr_t addr, unsigned long size)
269 unsigned long flags = _PAGE_NO_CACHE;
270 void *caller = __builtin_return_address(0);
272 if (ppc_md.ioremap)
273 return ppc_md.ioremap(addr, size, flags, caller);
274 return __ioremap_caller(addr, size, flags, caller);
277 void __iomem * ioremap_prot(phys_addr_t addr, unsigned long size,
278 unsigned long flags)
280 void *caller = __builtin_return_address(0);
282 /* writeable implies dirty for kernel addresses */
283 if (flags & _PAGE_RW)
284 flags |= _PAGE_DIRTY;
286 /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
287 flags &= ~(_PAGE_USER | _PAGE_EXEC);
289 #ifdef _PAGE_BAP_SR
290 /* _PAGE_USER contains _PAGE_BAP_SR on BookE using the new PTE format
291 * which means that we just cleared supervisor access... oops ;-) This
292 * restores it
294 flags |= _PAGE_BAP_SR;
295 #endif
297 if (ppc_md.ioremap)
298 return ppc_md.ioremap(addr, size, flags, caller);
299 return __ioremap_caller(addr, size, flags, caller);
304 * Unmap an IO region and remove it from imalloc'd list.
305 * Access to IO memory should be serialized by driver.
307 void __iounmap(volatile void __iomem *token)
309 void *addr;
311 if (!mem_init_done)
312 return;
314 addr = (void *) ((unsigned long __force)
315 PCI_FIX_ADDR(token) & PAGE_MASK);
316 if ((unsigned long)addr < ioremap_bot) {
317 printk(KERN_WARNING "Attempt to iounmap early bolted mapping"
318 " at 0x%p\n", addr);
319 return;
321 vunmap(addr);
324 void iounmap(volatile void __iomem *token)
326 if (ppc_md.iounmap)
327 ppc_md.iounmap(token);
328 else
329 __iounmap(token);
332 EXPORT_SYMBOL(ioremap);
333 EXPORT_SYMBOL(ioremap_wc);
334 EXPORT_SYMBOL(ioremap_prot);
335 EXPORT_SYMBOL(__ioremap);
336 EXPORT_SYMBOL(__ioremap_at);
337 EXPORT_SYMBOL(iounmap);
338 EXPORT_SYMBOL(__iounmap);
339 EXPORT_SYMBOL(__iounmap_at);
342 * For hugepage we have pfn in the pmd, we use PTE_RPN_SHIFT bits for flags
343 * For PTE page, we have a PTE_FRAG_SIZE (4K) aligned virtual address.
345 struct page *pmd_page(pmd_t pmd)
347 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
348 if (pmd_trans_huge(pmd))
349 return pfn_to_page(pmd_pfn(pmd));
350 #endif
351 return virt_to_page(pmd_page_vaddr(pmd));
354 #ifdef CONFIG_PPC_64K_PAGES
355 static pte_t *get_from_cache(struct mm_struct *mm)
357 void *pte_frag, *ret;
359 spin_lock(&mm->page_table_lock);
360 ret = mm->context.pte_frag;
361 if (ret) {
362 pte_frag = ret + PTE_FRAG_SIZE;
364 * If we have taken up all the fragments mark PTE page NULL
366 if (((unsigned long)pte_frag & ~PAGE_MASK) == 0)
367 pte_frag = NULL;
368 mm->context.pte_frag = pte_frag;
370 spin_unlock(&mm->page_table_lock);
371 return (pte_t *)ret;
374 static pte_t *__alloc_for_cache(struct mm_struct *mm, int kernel)
376 void *ret = NULL;
377 struct page *page = alloc_page(GFP_KERNEL | __GFP_NOTRACK |
378 __GFP_REPEAT | __GFP_ZERO);
379 if (!page)
380 return NULL;
382 ret = page_address(page);
383 spin_lock(&mm->page_table_lock);
385 * If we find pgtable_page set, we return
386 * the allocated page with single fragement
387 * count.
389 if (likely(!mm->context.pte_frag)) {
390 atomic_set(&page->_count, PTE_FRAG_NR);
391 mm->context.pte_frag = ret + PTE_FRAG_SIZE;
393 spin_unlock(&mm->page_table_lock);
395 if (!kernel)
396 pgtable_page_ctor(page);
398 return (pte_t *)ret;
401 pte_t *page_table_alloc(struct mm_struct *mm, unsigned long vmaddr, int kernel)
403 pte_t *pte;
405 pte = get_from_cache(mm);
406 if (pte)
407 return pte;
409 return __alloc_for_cache(mm, kernel);
412 void page_table_free(struct mm_struct *mm, unsigned long *table, int kernel)
414 struct page *page = virt_to_page(table);
415 if (put_page_testzero(page)) {
416 if (!kernel)
417 pgtable_page_dtor(page);
418 free_hot_cold_page(page, 0);
422 #ifdef CONFIG_SMP
423 static void page_table_free_rcu(void *table)
425 struct page *page = virt_to_page(table);
426 if (put_page_testzero(page)) {
427 pgtable_page_dtor(page);
428 free_hot_cold_page(page, 0);
432 void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
434 unsigned long pgf = (unsigned long)table;
436 BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
437 pgf |= shift;
438 tlb_remove_table(tlb, (void *)pgf);
441 void __tlb_remove_table(void *_table)
443 void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
444 unsigned shift = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
446 if (!shift)
447 /* PTE page needs special handling */
448 page_table_free_rcu(table);
449 else {
450 BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
451 kmem_cache_free(PGT_CACHE(shift), table);
454 #else
455 void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
457 if (!shift) {
458 /* PTE page needs special handling */
459 struct page *page = virt_to_page(table);
460 if (put_page_testzero(page)) {
461 pgtable_page_dtor(page);
462 free_hot_cold_page(page, 0);
464 } else {
465 BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
466 kmem_cache_free(PGT_CACHE(shift), table);
469 #endif
470 #endif /* CONFIG_PPC_64K_PAGES */
472 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
475 * This is called when relaxing access to a hugepage. It's also called in the page
476 * fault path when we don't hit any of the major fault cases, ie, a minor
477 * update of _PAGE_ACCESSED, _PAGE_DIRTY, etc... The generic code will have
478 * handled those two for us, we additionally deal with missing execute
479 * permission here on some processors
481 int pmdp_set_access_flags(struct vm_area_struct *vma, unsigned long address,
482 pmd_t *pmdp, pmd_t entry, int dirty)
484 int changed;
485 #ifdef CONFIG_DEBUG_VM
486 WARN_ON(!pmd_trans_huge(*pmdp));
487 assert_spin_locked(&vma->vm_mm->page_table_lock);
488 #endif
489 changed = !pmd_same(*(pmdp), entry);
490 if (changed) {
491 __ptep_set_access_flags(pmdp_ptep(pmdp), pmd_pte(entry));
493 * Since we are not supporting SW TLB systems, we don't
494 * have any thing similar to flush_tlb_page_nohash()
497 return changed;
500 unsigned long pmd_hugepage_update(struct mm_struct *mm, unsigned long addr,
501 pmd_t *pmdp, unsigned long clr)
504 unsigned long old, tmp;
506 #ifdef CONFIG_DEBUG_VM
507 WARN_ON(!pmd_trans_huge(*pmdp));
508 assert_spin_locked(&mm->page_table_lock);
509 #endif
511 #ifdef PTE_ATOMIC_UPDATES
512 __asm__ __volatile__(
513 "1: ldarx %0,0,%3\n\
514 andi. %1,%0,%6\n\
515 bne- 1b \n\
516 andc %1,%0,%4 \n\
517 stdcx. %1,0,%3 \n\
518 bne- 1b"
519 : "=&r" (old), "=&r" (tmp), "=m" (*pmdp)
520 : "r" (pmdp), "r" (clr), "m" (*pmdp), "i" (_PAGE_BUSY)
521 : "cc" );
522 #else
523 old = pmd_val(*pmdp);
524 *pmdp = __pmd(old & ~clr);
525 #endif
526 if (old & _PAGE_HASHPTE)
527 hpte_do_hugepage_flush(mm, addr, pmdp);
528 return old;
531 pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address,
532 pmd_t *pmdp)
534 pmd_t pmd;
536 VM_BUG_ON(address & ~HPAGE_PMD_MASK);
537 if (pmd_trans_huge(*pmdp)) {
538 pmd = pmdp_get_and_clear(vma->vm_mm, address, pmdp);
539 } else {
541 * khugepaged calls this for normal pmd
543 pmd = *pmdp;
544 pmd_clear(pmdp);
546 * Wait for all pending hash_page to finish. This is needed
547 * in case of subpage collapse. When we collapse normal pages
548 * to hugepage, we first clear the pmd, then invalidate all
549 * the PTE entries. The assumption here is that any low level
550 * page fault will see a none pmd and take the slow path that
551 * will wait on mmap_sem. But we could very well be in a
552 * hash_page with local ptep pointer value. Such a hash page
553 * can result in adding new HPTE entries for normal subpages.
554 * That means we could be modifying the page content as we
555 * copy them to a huge page. So wait for parallel hash_page
556 * to finish before invalidating HPTE entries. We can do this
557 * by sending an IPI to all the cpus and executing a dummy
558 * function there.
560 kick_all_cpus_sync();
562 * Now invalidate the hpte entries in the range
563 * covered by pmd. This make sure we take a
564 * fault and will find the pmd as none, which will
565 * result in a major fault which takes mmap_sem and
566 * hence wait for collapse to complete. Without this
567 * the __collapse_huge_page_copy can result in copying
568 * the old content.
570 flush_tlb_pmd_range(vma->vm_mm, &pmd, address);
572 return pmd;
575 int pmdp_test_and_clear_young(struct vm_area_struct *vma,
576 unsigned long address, pmd_t *pmdp)
578 return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp);
582 * We currently remove entries from the hashtable regardless of whether
583 * the entry was young or dirty. The generic routines only flush if the
584 * entry was young or dirty which is not good enough.
586 * We should be more intelligent about this but for the moment we override
587 * these functions and force a tlb flush unconditionally
589 int pmdp_clear_flush_young(struct vm_area_struct *vma,
590 unsigned long address, pmd_t *pmdp)
592 return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp);
596 * We mark the pmd splitting and invalidate all the hpte
597 * entries for this hugepage.
599 void pmdp_splitting_flush(struct vm_area_struct *vma,
600 unsigned long address, pmd_t *pmdp)
602 unsigned long old, tmp;
604 VM_BUG_ON(address & ~HPAGE_PMD_MASK);
606 #ifdef CONFIG_DEBUG_VM
607 WARN_ON(!pmd_trans_huge(*pmdp));
608 assert_spin_locked(&vma->vm_mm->page_table_lock);
609 #endif
611 #ifdef PTE_ATOMIC_UPDATES
613 __asm__ __volatile__(
614 "1: ldarx %0,0,%3\n\
615 andi. %1,%0,%6\n\
616 bne- 1b \n\
617 ori %1,%0,%4 \n\
618 stdcx. %1,0,%3 \n\
619 bne- 1b"
620 : "=&r" (old), "=&r" (tmp), "=m" (*pmdp)
621 : "r" (pmdp), "i" (_PAGE_SPLITTING), "m" (*pmdp), "i" (_PAGE_BUSY)
622 : "cc" );
623 #else
624 old = pmd_val(*pmdp);
625 *pmdp = __pmd(old | _PAGE_SPLITTING);
626 #endif
628 * If we didn't had the splitting flag set, go and flush the
629 * HPTE entries.
631 if (!(old & _PAGE_SPLITTING)) {
632 /* We need to flush the hpte */
633 if (old & _PAGE_HASHPTE)
634 hpte_do_hugepage_flush(vma->vm_mm, address, pmdp);
639 * We want to put the pgtable in pmd and use pgtable for tracking
640 * the base page size hptes
642 void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
643 pgtable_t pgtable)
645 pgtable_t *pgtable_slot;
646 assert_spin_locked(&mm->page_table_lock);
648 * we store the pgtable in the second half of PMD
650 pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD;
651 *pgtable_slot = pgtable;
653 * expose the deposited pgtable to other cpus.
654 * before we set the hugepage PTE at pmd level
655 * hash fault code looks at the deposted pgtable
656 * to store hash index values.
658 smp_wmb();
661 pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
663 pgtable_t pgtable;
664 pgtable_t *pgtable_slot;
666 assert_spin_locked(&mm->page_table_lock);
667 pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD;
668 pgtable = *pgtable_slot;
670 * Once we withdraw, mark the entry NULL.
672 *pgtable_slot = NULL;
674 * We store HPTE information in the deposited PTE fragment.
675 * zero out the content on withdraw.
677 memset(pgtable, 0, PTE_FRAG_SIZE);
678 return pgtable;
682 * set a new huge pmd. We should not be called for updating
683 * an existing pmd entry. That should go via pmd_hugepage_update.
685 void set_pmd_at(struct mm_struct *mm, unsigned long addr,
686 pmd_t *pmdp, pmd_t pmd)
688 #ifdef CONFIG_DEBUG_VM
689 WARN_ON(!pmd_none(*pmdp));
690 assert_spin_locked(&mm->page_table_lock);
691 WARN_ON(!pmd_trans_huge(pmd));
692 #endif
693 return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
696 void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
697 pmd_t *pmdp)
699 pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT);
703 * A linux hugepage PMD was changed and the corresponding hash table entries
704 * neesd to be flushed.
706 void hpte_do_hugepage_flush(struct mm_struct *mm, unsigned long addr,
707 pmd_t *pmdp)
709 int ssize, i;
710 unsigned long s_addr;
711 int max_hpte_count;
712 unsigned int psize, valid;
713 unsigned char *hpte_slot_array;
714 unsigned long hidx, vpn, vsid, hash, shift, slot;
717 * Flush all the hptes mapping this hugepage
719 s_addr = addr & HPAGE_PMD_MASK;
720 hpte_slot_array = get_hpte_slot_array(pmdp);
722 * IF we try to do a HUGE PTE update after a withdraw is done.
723 * we will find the below NULL. This happens when we do
724 * split_huge_page_pmd
726 if (!hpte_slot_array)
727 return;
729 /* get the base page size */
730 psize = get_slice_psize(mm, s_addr);
732 if (ppc_md.hugepage_invalidate)
733 return ppc_md.hugepage_invalidate(mm, hpte_slot_array,
734 s_addr, psize);
736 * No bluk hpte removal support, invalidate each entry
738 shift = mmu_psize_defs[psize].shift;
739 max_hpte_count = HPAGE_PMD_SIZE >> shift;
740 for (i = 0; i < max_hpte_count; i++) {
742 * 8 bits per each hpte entries
743 * 000| [ secondary group (one bit) | hidx (3 bits) | valid bit]
745 valid = hpte_valid(hpte_slot_array, i);
746 if (!valid)
747 continue;
748 hidx = hpte_hash_index(hpte_slot_array, i);
750 /* get the vpn */
751 addr = s_addr + (i * (1ul << shift));
752 if (!is_kernel_addr(addr)) {
753 ssize = user_segment_size(addr);
754 vsid = get_vsid(mm->context.id, addr, ssize);
755 WARN_ON(vsid == 0);
756 } else {
757 vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
758 ssize = mmu_kernel_ssize;
761 vpn = hpt_vpn(addr, vsid, ssize);
762 hash = hpt_hash(vpn, shift, ssize);
763 if (hidx & _PTEIDX_SECONDARY)
764 hash = ~hash;
766 slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
767 slot += hidx & _PTEIDX_GROUP_IX;
768 ppc_md.hpte_invalidate(slot, vpn, psize,
769 MMU_PAGE_16M, ssize, 0);
773 static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot)
775 pmd_val(pmd) |= pgprot_val(pgprot);
776 return pmd;
779 pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot)
781 pmd_t pmd;
783 * For a valid pte, we would have _PAGE_PRESENT or _PAGE_FILE always
784 * set. We use this to check THP page at pmd level.
785 * leaf pte for huge page, bottom two bits != 00
787 pmd_val(pmd) = pfn << PTE_RPN_SHIFT;
788 pmd_val(pmd) |= _PAGE_THP_HUGE;
789 pmd = pmd_set_protbits(pmd, pgprot);
790 return pmd;
793 pmd_t mk_pmd(struct page *page, pgprot_t pgprot)
795 return pfn_pmd(page_to_pfn(page), pgprot);
798 pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
801 pmd_val(pmd) &= _HPAGE_CHG_MASK;
802 pmd = pmd_set_protbits(pmd, newprot);
803 return pmd;
807 * This is called at the end of handling a user page fault, when the
808 * fault has been handled by updating a HUGE PMD entry in the linux page tables.
809 * We use it to preload an HPTE into the hash table corresponding to
810 * the updated linux HUGE PMD entry.
812 void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
813 pmd_t *pmd)
815 return;
818 pmd_t pmdp_get_and_clear(struct mm_struct *mm,
819 unsigned long addr, pmd_t *pmdp)
821 pmd_t old_pmd;
822 pgtable_t pgtable;
823 unsigned long old;
824 pgtable_t *pgtable_slot;
826 old = pmd_hugepage_update(mm, addr, pmdp, ~0UL);
827 old_pmd = __pmd(old);
829 * We have pmd == none and we are holding page_table_lock.
830 * So we can safely go and clear the pgtable hash
831 * index info.
833 pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD;
834 pgtable = *pgtable_slot;
836 * Let's zero out old valid and hash index details
837 * hash fault look at them.
839 memset(pgtable, 0, PTE_FRAG_SIZE);
840 return old_pmd;
843 int has_transparent_hugepage(void)
845 if (!mmu_has_feature(MMU_FTR_16M_PAGE))
846 return 0;
848 * We support THP only if PMD_SIZE is 16MB.
850 if (mmu_psize_defs[MMU_PAGE_16M].shift != PMD_SHIFT)
851 return 0;
853 * We need to make sure that we support 16MB hugepage in a segement
854 * with base page size 64K or 4K. We only enable THP with a PAGE_SIZE
855 * of 64K.
858 * If we have 64K HPTE, we will be using that by default
860 if (mmu_psize_defs[MMU_PAGE_64K].shift &&
861 (mmu_psize_defs[MMU_PAGE_64K].penc[MMU_PAGE_16M] == -1))
862 return 0;
864 * Ok we only have 4K HPTE
866 if (mmu_psize_defs[MMU_PAGE_4K].penc[MMU_PAGE_16M] == -1)
867 return 0;
869 return 1;
871 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */