2 * PowerPC64 port by Mike Corrigan and Dave Engebretsen
3 * {mikejc|engebret}@us.ibm.com
5 * Copyright (c) 2000 Mike Corrigan <mikejc@us.ibm.com>
7 * SMP scalability work:
8 * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
13 * PowerPC Hashed Page Table functions
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
24 #include <linux/config.h>
25 #include <linux/spinlock.h>
26 #include <linux/errno.h>
27 #include <linux/sched.h>
28 #include <linux/proc_fs.h>
29 #include <linux/stat.h>
30 #include <linux/sysctl.h>
31 #include <linux/ctype.h>
32 #include <linux/cache.h>
33 #include <linux/init.h>
34 #include <linux/signal.h>
36 #include <asm/processor.h>
37 #include <asm/pgtable.h>
39 #include <asm/mmu_context.h>
41 #include <asm/types.h>
42 #include <asm/system.h>
43 #include <asm/uaccess.h>
44 #include <asm/machdep.h>
46 #include <asm/abs_addr.h>
47 #include <asm/tlbflush.h>
51 #include <asm/cacheflush.h>
52 #include <asm/cputable.h>
53 #include <asm/abs_addr.h>
54 #include <asm/sections.h>
57 #define DBG(fmt...) udbg_printf(fmt)
63 #define DBG_LOW(fmt...) udbg_printf(fmt)
65 #define DBG_LOW(fmt...)
72 * Note: pte --> Linux PTE
73 * HPTE --> PowerPC Hashed Page Table Entry
76 * htab_initialize is called with the MMU off (of course), but
77 * the kernel has been copied down to zero so it can directly
78 * reference global data. At this point it is very difficult
79 * to print debug info.
84 extern unsigned long dart_tablebase;
85 #endif /* CONFIG_U3_DART */
87 static unsigned long _SDR1;
88 struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];
91 unsigned long htab_size_bytes;
92 unsigned long htab_hash_mask;
93 int mmu_linear_psize = MMU_PAGE_4K;
94 int mmu_virtual_psize = MMU_PAGE_4K;
95 int mmu_vmalloc_psize = MMU_PAGE_4K;
96 int mmu_io_psize = MMU_PAGE_4K;
97 #ifdef CONFIG_HUGETLB_PAGE
98 int mmu_huge_psize = MMU_PAGE_16M;
99 unsigned int HPAGE_SHIFT;
101 #ifdef CONFIG_PPC_64K_PAGES
102 int mmu_ci_restrictions;
105 /* There are definitions of page sizes arrays to be used when none
106 * is provided by the firmware.
109 /* Pre-POWER4 CPUs (4k pages only)
111 struct mmu_psize_def mmu_psize_defaults_old[] = {
121 /* POWER4, GPUL, POWER5
123 * Support for 16Mb large pages
125 struct mmu_psize_def mmu_psize_defaults_gp[] = {
143 int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
144 unsigned long pstart, unsigned long mode, int psize)
146 unsigned long vaddr, paddr;
147 unsigned int step, shift;
148 unsigned long tmp_mode;
151 shift = mmu_psize_defs[psize].shift;
154 for (vaddr = vstart, paddr = pstart; vaddr < vend;
155 vaddr += step, paddr += step) {
156 unsigned long vpn, hash, hpteg;
157 unsigned long vsid = get_kernel_vsid(vaddr);
158 unsigned long va = (vsid << 28) | (vaddr & 0x0fffffff);
163 /* Make non-kernel text non-executable */
164 if (!in_kernel_text(vaddr))
165 tmp_mode = mode | HPTE_R_N;
167 hash = hpt_hash(va, shift);
168 hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
170 /* The crap below can be cleaned once ppd_md.probe() can
171 * set up the hash callbacks, thus we can just used the
172 * normal insert callback here.
174 #ifdef CONFIG_PPC_ISERIES
175 if (machine_is(iseries))
176 ret = iSeries_hpte_insert(hpteg, va,
183 #ifdef CONFIG_PPC_PSERIES
184 if (machine_is(pseries) && firmware_has_feature(FW_FEATURE_LPAR))
185 ret = pSeries_lpar_hpte_insert(hpteg, va,
192 #ifdef CONFIG_PPC_MULTIPLATFORM
193 ret = native_hpte_insert(hpteg, va,
195 tmp_mode, HPTE_V_BOLTED,
201 return ret < 0 ? ret : 0;
204 static int __init htab_dt_scan_page_sizes(unsigned long node,
205 const char *uname, int depth,
208 char *type = of_get_flat_dt_prop(node, "device_type", NULL);
210 unsigned long size = 0;
212 /* We are scanning "cpu" nodes only */
213 if (type == NULL || strcmp(type, "cpu") != 0)
216 prop = (u32 *)of_get_flat_dt_prop(node,
217 "ibm,segment-page-sizes", &size);
219 DBG("Page sizes from device-tree:\n");
221 cur_cpu_spec->cpu_features &= ~(CPU_FTR_16M_PAGE);
223 unsigned int shift = prop[0];
224 unsigned int slbenc = prop[1];
225 unsigned int lpnum = prop[2];
226 unsigned int lpenc = 0;
227 struct mmu_psize_def *def;
230 size -= 3; prop += 3;
231 while(size > 0 && lpnum) {
232 if (prop[0] == shift)
234 prop += 2; size -= 2;
249 cur_cpu_spec->cpu_features |= CPU_FTR_16M_PAGE;
257 def = &mmu_psize_defs[idx];
262 def->avpnm = (1 << (shift - 23)) - 1;
265 /* We don't know for sure what's up with tlbiel, so
266 * for now we only set it for 4K and 64K pages
268 if (idx == MMU_PAGE_4K || idx == MMU_PAGE_64K)
273 DBG(" %d: shift=%02x, sllp=%04x, avpnm=%08x, "
274 "tlbiel=%d, penc=%d\n",
275 idx, shift, def->sllp, def->avpnm, def->tlbiel,
284 static void __init htab_init_page_sizes(void)
288 /* Default to 4K pages only */
289 memcpy(mmu_psize_defs, mmu_psize_defaults_old,
290 sizeof(mmu_psize_defaults_old));
293 * Try to find the available page sizes in the device-tree
295 rc = of_scan_flat_dt(htab_dt_scan_page_sizes, NULL);
296 if (rc != 0) /* Found */
300 * Not in the device-tree, let's fallback on known size
301 * list for 16M capable GP & GR
303 if (cpu_has_feature(CPU_FTR_16M_PAGE) && !machine_is(iseries))
304 memcpy(mmu_psize_defs, mmu_psize_defaults_gp,
305 sizeof(mmu_psize_defaults_gp));
308 * Pick a size for the linear mapping. Currently, we only support
309 * 16M, 1M and 4K which is the default
311 if (mmu_psize_defs[MMU_PAGE_16M].shift)
312 mmu_linear_psize = MMU_PAGE_16M;
313 else if (mmu_psize_defs[MMU_PAGE_1M].shift)
314 mmu_linear_psize = MMU_PAGE_1M;
316 #ifdef CONFIG_PPC_64K_PAGES
318 * Pick a size for the ordinary pages. Default is 4K, we support
319 * 64K for user mappings and vmalloc if supported by the processor.
320 * We only use 64k for ioremap if the processor
321 * (and firmware) support cache-inhibited large pages.
322 * If not, we use 4k and set mmu_ci_restrictions so that
323 * hash_page knows to switch processes that use cache-inhibited
324 * mappings to 4k pages.
326 if (mmu_psize_defs[MMU_PAGE_64K].shift) {
327 mmu_virtual_psize = MMU_PAGE_64K;
328 mmu_vmalloc_psize = MMU_PAGE_64K;
329 if (cpu_has_feature(CPU_FTR_CI_LARGE_PAGE))
330 mmu_io_psize = MMU_PAGE_64K;
332 mmu_ci_restrictions = 1;
336 printk(KERN_DEBUG "Page orders: linear mapping = %d, "
337 "virtual = %d, io = %d\n",
338 mmu_psize_defs[mmu_linear_psize].shift,
339 mmu_psize_defs[mmu_virtual_psize].shift,
340 mmu_psize_defs[mmu_io_psize].shift);
342 #ifdef CONFIG_HUGETLB_PAGE
343 /* Init large page size. Currently, we pick 16M or 1M depending
344 * on what is available
346 if (mmu_psize_defs[MMU_PAGE_16M].shift)
347 mmu_huge_psize = MMU_PAGE_16M;
348 /* With 4k/4level pagetables, we can't (for now) cope with a
349 * huge page size < PMD_SIZE */
350 else if (mmu_psize_defs[MMU_PAGE_1M].shift)
351 mmu_huge_psize = MMU_PAGE_1M;
353 /* Calculate HPAGE_SHIFT and sanity check it */
354 if (mmu_psize_defs[mmu_huge_psize].shift > MIN_HUGEPTE_SHIFT &&
355 mmu_psize_defs[mmu_huge_psize].shift < SID_SHIFT)
356 HPAGE_SHIFT = mmu_psize_defs[mmu_huge_psize].shift;
358 HPAGE_SHIFT = 0; /* No huge pages dude ! */
359 #endif /* CONFIG_HUGETLB_PAGE */
362 static int __init htab_dt_scan_pftsize(unsigned long node,
363 const char *uname, int depth,
366 char *type = of_get_flat_dt_prop(node, "device_type", NULL);
369 /* We are scanning "cpu" nodes only */
370 if (type == NULL || strcmp(type, "cpu") != 0)
373 prop = (u32 *)of_get_flat_dt_prop(node, "ibm,pft-size", NULL);
375 /* pft_size[0] is the NUMA CEC cookie */
376 ppc64_pft_size = prop[1];
382 static unsigned long __init htab_get_table_size(void)
384 unsigned long mem_size, rnd_mem_size, pteg_count;
386 /* If hash size isn't already provided by the platform, we try to
387 * retrieve it from the device-tree. If it's not there neither, we
388 * calculate it now based on the total RAM size
390 if (ppc64_pft_size == 0)
391 of_scan_flat_dt(htab_dt_scan_pftsize, NULL);
393 return 1UL << ppc64_pft_size;
395 /* round mem_size up to next power of 2 */
396 mem_size = lmb_phys_mem_size();
397 rnd_mem_size = 1UL << __ilog2(mem_size);
398 if (rnd_mem_size < mem_size)
402 pteg_count = max(rnd_mem_size >> (12 + 1), 1UL << 11);
404 return pteg_count << 7;
407 #ifdef CONFIG_MEMORY_HOTPLUG
408 void create_section_mapping(unsigned long start, unsigned long end)
410 BUG_ON(htab_bolt_mapping(start, end, __pa(start),
411 _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_COHERENT | PP_RWXX,
414 #endif /* CONFIG_MEMORY_HOTPLUG */
416 void __init htab_initialize(void)
419 unsigned long pteg_count;
420 unsigned long mode_rw;
421 unsigned long base = 0, size = 0;
424 extern unsigned long tce_alloc_start, tce_alloc_end;
426 DBG(" -> htab_initialize()\n");
428 /* Initialize page sizes */
429 htab_init_page_sizes();
432 * Calculate the required size of the htab. We want the number of
433 * PTEGs to equal one half the number of real pages.
435 htab_size_bytes = htab_get_table_size();
436 pteg_count = htab_size_bytes >> 7;
438 htab_hash_mask = pteg_count - 1;
440 if (firmware_has_feature(FW_FEATURE_LPAR)) {
441 /* Using a hypervisor which owns the htab */
445 /* Find storage for the HPT. Must be contiguous in
446 * the absolute address space.
448 table = lmb_alloc(htab_size_bytes, htab_size_bytes);
450 DBG("Hash table allocated at %lx, size: %lx\n", table,
453 htab_address = abs_to_virt(table);
455 /* htab absolute addr + encoded htabsize */
456 _SDR1 = table + __ilog2(pteg_count) - 11;
458 /* Initialize the HPT with no entries */
459 memset((void *)table, 0, htab_size_bytes);
462 mtspr(SPRN_SDR1, _SDR1);
465 mode_rw = _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_COHERENT | PP_RWXX;
467 /* On U3 based machines, we need to reserve the DART area and
468 * _NOT_ map it to avoid cache paradoxes as it's remapped non
472 /* create bolted the linear mapping in the hash table */
473 for (i=0; i < lmb.memory.cnt; i++) {
474 base = (unsigned long)__va(lmb.memory.region[i].base);
475 size = lmb.memory.region[i].size;
477 DBG("creating mapping for region: %lx : %lx\n", base, size);
479 #ifdef CONFIG_U3_DART
480 /* Do not map the DART space. Fortunately, it will be aligned
481 * in such a way that it will not cross two lmb regions and
482 * will fit within a single 16Mb page.
483 * The DART space is assumed to be a full 16Mb region even if
484 * we only use 2Mb of that space. We will use more of it later
485 * for AGP GART. We have to use a full 16Mb large page.
487 DBG("DART base: %lx\n", dart_tablebase);
489 if (dart_tablebase != 0 && dart_tablebase >= base
490 && dart_tablebase < (base + size)) {
491 unsigned long dart_table_end = dart_tablebase + 16 * MB;
492 if (base != dart_tablebase)
493 BUG_ON(htab_bolt_mapping(base, dart_tablebase,
496 if ((base + size) > dart_table_end)
497 BUG_ON(htab_bolt_mapping(dart_tablebase+16*MB,
499 __pa(dart_table_end),
504 #endif /* CONFIG_U3_DART */
505 BUG_ON(htab_bolt_mapping(base, base + size, __pa(base),
506 mode_rw, mmu_linear_psize));
510 * If we have a memory_limit and we've allocated TCEs then we need to
511 * explicitly map the TCE area at the top of RAM. We also cope with the
512 * case that the TCEs start below memory_limit.
513 * tce_alloc_start/end are 16MB aligned so the mapping should work
514 * for either 4K or 16MB pages.
516 if (tce_alloc_start) {
517 tce_alloc_start = (unsigned long)__va(tce_alloc_start);
518 tce_alloc_end = (unsigned long)__va(tce_alloc_end);
520 if (base + size >= tce_alloc_start)
521 tce_alloc_start = base + size + 1;
523 BUG_ON(htab_bolt_mapping(tce_alloc_start, tce_alloc_end,
524 __pa(tce_alloc_start), mode_rw,
528 DBG(" <- htab_initialize()\n");
533 void htab_initialize_secondary(void)
535 if (!firmware_has_feature(FW_FEATURE_LPAR))
536 mtspr(SPRN_SDR1, _SDR1);
540 * Called by asm hashtable.S for doing lazy icache flush
542 unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap)
546 if (!pfn_valid(pte_pfn(pte)))
549 page = pte_page(pte);
552 if (!test_bit(PG_arch_1, &page->flags) && !PageReserved(page)) {
554 __flush_dcache_icache(page_address(page));
555 set_bit(PG_arch_1, &page->flags);
564 * 1 - normal page fault
565 * -1 - critical hash insertion error
567 int hash_page(unsigned long ea, unsigned long access, unsigned long trap)
571 struct mm_struct *mm;
574 int rc, user_region = 0, local = 0;
577 DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n",
580 if ((ea & ~REGION_MASK) >= PGTABLE_RANGE) {
581 DBG_LOW(" out of pgtable range !\n");
585 /* Get region & vsid */
586 switch (REGION_ID(ea)) {
591 DBG_LOW(" user region with no mm !\n");
594 vsid = get_vsid(mm->context.id, ea);
595 psize = mm->context.user_psize;
597 case VMALLOC_REGION_ID:
599 vsid = get_kernel_vsid(ea);
600 if (ea < VMALLOC_END)
601 psize = mmu_vmalloc_psize;
603 psize = mmu_io_psize;
607 * Send the problem up to do_page_fault
611 DBG_LOW(" mm=%p, mm->pgdir=%p, vsid=%016lx\n", mm, mm->pgd, vsid);
618 /* Check CPU locality */
619 tmp = cpumask_of_cpu(smp_processor_id());
620 if (user_region && cpus_equal(mm->cpu_vm_mask, tmp))
623 /* Handle hugepage regions */
624 if (unlikely(in_hugepage_area(mm->context, ea))) {
625 DBG_LOW(" -> huge page !\n");
626 return hash_huge_page(mm, access, ea, vsid, local, trap);
629 /* Get PTE and page size from page tables */
630 ptep = find_linux_pte(pgdir, ea);
631 if (ptep == NULL || !pte_present(*ptep)) {
632 DBG_LOW(" no PTE !\n");
636 #ifndef CONFIG_PPC_64K_PAGES
637 DBG_LOW(" i-pte: %016lx\n", pte_val(*ptep));
639 DBG_LOW(" i-pte: %016lx %016lx\n", pte_val(*ptep),
640 pte_val(*(ptep + PTRS_PER_PTE)));
642 /* Pre-check access permissions (will be re-checked atomically
643 * in __hash_page_XX but this pre-check is a fast path
645 if (access & ~pte_val(*ptep)) {
646 DBG_LOW(" no access !\n");
650 /* Do actual hashing */
651 #ifndef CONFIG_PPC_64K_PAGES
652 rc = __hash_page_4K(ea, access, vsid, ptep, trap, local);
654 if (mmu_ci_restrictions) {
655 /* If this PTE is non-cacheable, switch to 4k */
656 if (psize == MMU_PAGE_64K &&
657 (pte_val(*ptep) & _PAGE_NO_CACHE)) {
660 mm->context.user_psize = MMU_PAGE_4K;
661 mm->context.sllp = SLB_VSID_USER |
662 mmu_psize_defs[MMU_PAGE_4K].sllp;
663 } else if (ea < VMALLOC_END) {
665 * some driver did a non-cacheable mapping
666 * in vmalloc space, so switch vmalloc
669 printk(KERN_ALERT "Reducing vmalloc segment "
670 "to 4kB pages because of "
671 "non-cacheable mapping\n");
672 psize = mmu_vmalloc_psize = MMU_PAGE_4K;
676 if (psize != get_paca()->context.user_psize) {
677 get_paca()->context = mm->context;
678 slb_flush_and_rebolt();
680 } else if (get_paca()->vmalloc_sllp !=
681 mmu_psize_defs[mmu_vmalloc_psize].sllp) {
682 get_paca()->vmalloc_sllp =
683 mmu_psize_defs[mmu_vmalloc_psize].sllp;
684 slb_flush_and_rebolt();
687 if (psize == MMU_PAGE_64K)
688 rc = __hash_page_64K(ea, access, vsid, ptep, trap, local);
690 rc = __hash_page_4K(ea, access, vsid, ptep, trap, local);
691 #endif /* CONFIG_PPC_64K_PAGES */
693 #ifndef CONFIG_PPC_64K_PAGES
694 DBG_LOW(" o-pte: %016lx\n", pte_val(*ptep));
696 DBG_LOW(" o-pte: %016lx %016lx\n", pte_val(*ptep),
697 pte_val(*(ptep + PTRS_PER_PTE)));
699 DBG_LOW(" -> rc=%d\n", rc);
702 EXPORT_SYMBOL_GPL(hash_page);
704 void hash_preload(struct mm_struct *mm, unsigned long ea,
705 unsigned long access, unsigned long trap)
714 /* We don't want huge pages prefaulted for now
716 if (unlikely(in_hugepage_area(mm->context, ea)))
719 DBG_LOW("hash_preload(mm=%p, mm->pgdir=%p, ea=%016lx, access=%lx,"
720 " trap=%lx\n", mm, mm->pgd, ea, access, trap);
722 /* Get PTE, VSID, access mask */
726 ptep = find_linux_pte(pgdir, ea);
729 vsid = get_vsid(mm->context.id, ea);
732 local_irq_save(flags);
733 mask = cpumask_of_cpu(smp_processor_id());
734 if (cpus_equal(mm->cpu_vm_mask, mask))
736 #ifndef CONFIG_PPC_64K_PAGES
737 __hash_page_4K(ea, access, vsid, ptep, trap, local);
739 if (mmu_ci_restrictions) {
740 /* If this PTE is non-cacheable, switch to 4k */
741 if (mm->context.user_psize == MMU_PAGE_64K &&
742 (pte_val(*ptep) & _PAGE_NO_CACHE)) {
743 mm->context.user_psize = MMU_PAGE_4K;
744 mm->context.sllp = SLB_VSID_USER |
745 mmu_psize_defs[MMU_PAGE_4K].sllp;
746 get_paca()->context = mm->context;
747 slb_flush_and_rebolt();
750 if (mm->context.user_psize == MMU_PAGE_64K)
751 __hash_page_64K(ea, access, vsid, ptep, trap, local);
753 __hash_page_4K(ea, access, vsid, ptep, trap, local);
754 #endif /* CONFIG_PPC_64K_PAGES */
755 local_irq_restore(flags);
758 void flush_hash_page(unsigned long va, real_pte_t pte, int psize, int local)
760 unsigned long hash, index, shift, hidx, slot;
762 DBG_LOW("flush_hash_page(va=%016x)\n", va);
763 pte_iterate_hashed_subpages(pte, psize, va, index, shift) {
764 hash = hpt_hash(va, shift);
765 hidx = __rpte_to_hidx(pte, index);
766 if (hidx & _PTEIDX_SECONDARY)
768 slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
769 slot += hidx & _PTEIDX_GROUP_IX;
770 DBG_LOW(" sub %d: hash=%x, hidx=%x\n", index, slot, hidx);
771 ppc_md.hpte_invalidate(slot, va, psize, local);
772 } pte_iterate_hashed_end();
775 void flush_hash_range(unsigned long number, int local)
777 if (ppc_md.flush_hash_range)
778 ppc_md.flush_hash_range(number, local);
781 struct ppc64_tlb_batch *batch =
782 &__get_cpu_var(ppc64_tlb_batch);
784 for (i = 0; i < number; i++)
785 flush_hash_page(batch->vaddr[i], batch->pte[i],
786 batch->psize, local);
790 static inline void make_bl(unsigned int *insn_addr, void *func)
792 unsigned long funcp = *((unsigned long *)func);
793 int offset = funcp - (unsigned long)insn_addr;
795 *insn_addr = (unsigned int)(0x48000001 | (offset & 0x03fffffc));
796 flush_icache_range((unsigned long)insn_addr, 4+
797 (unsigned long)insn_addr);
801 * low_hash_fault is called when we the low level hash code failed
802 * to instert a PTE due to an hypervisor error
804 void low_hash_fault(struct pt_regs *regs, unsigned long address)
806 if (user_mode(regs)) {
809 info.si_signo = SIGBUS;
811 info.si_code = BUS_ADRERR;
812 info.si_addr = (void __user *)address;
813 force_sig_info(SIGBUS, &info, current);
816 bad_page_fault(regs, address, SIGBUS);
819 void __init htab_finish_init(void)
821 extern unsigned int *htab_call_hpte_insert1;
822 extern unsigned int *htab_call_hpte_insert2;
823 extern unsigned int *htab_call_hpte_remove;
824 extern unsigned int *htab_call_hpte_updatepp;
826 #ifdef CONFIG_PPC_64K_PAGES
827 extern unsigned int *ht64_call_hpte_insert1;
828 extern unsigned int *ht64_call_hpte_insert2;
829 extern unsigned int *ht64_call_hpte_remove;
830 extern unsigned int *ht64_call_hpte_updatepp;
832 make_bl(ht64_call_hpte_insert1, ppc_md.hpte_insert);
833 make_bl(ht64_call_hpte_insert2, ppc_md.hpte_insert);
834 make_bl(ht64_call_hpte_remove, ppc_md.hpte_remove);
835 make_bl(ht64_call_hpte_updatepp, ppc_md.hpte_updatepp);
836 #endif /* CONFIG_PPC_64K_PAGES */
838 make_bl(htab_call_hpte_insert1, ppc_md.hpte_insert);
839 make_bl(htab_call_hpte_insert2, ppc_md.hpte_insert);
840 make_bl(htab_call_hpte_remove, ppc_md.hpte_remove);
841 make_bl(htab_call_hpte_updatepp, ppc_md.hpte_updatepp);