1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * PowerPC64 port by Mike Corrigan and Dave Engebretsen
4 * {mikejc|engebret}@us.ibm.com
6 * Copyright (c) 2000 Mike Corrigan <mikejc@us.ibm.com>
8 * SMP scalability work:
9 * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
14 * PowerPC Hashed Page Table functions
20 #define pr_fmt(fmt) "hash-mmu: " fmt
21 #include <linux/spinlock.h>
22 #include <linux/errno.h>
23 #include <linux/sched/mm.h>
24 #include <linux/proc_fs.h>
25 #include <linux/stat.h>
26 #include <linux/sysctl.h>
27 #include <linux/export.h>
28 #include <linux/ctype.h>
29 #include <linux/cache.h>
30 #include <linux/init.h>
31 #include <linux/signal.h>
32 #include <linux/memblock.h>
33 #include <linux/context_tracking.h>
34 #include <linux/libfdt.h>
35 #include <linux/pkeys.h>
36 #include <linux/hugetlb.h>
37 #include <linux/cpu.h>
38 #include <linux/pgtable.h>
40 #include <asm/debugfs.h>
41 #include <asm/processor.h>
43 #include <asm/mmu_context.h>
45 #include <asm/types.h>
46 #include <linux/uaccess.h>
47 #include <asm/machdep.h>
52 #include <asm/cacheflush.h>
53 #include <asm/cputable.h>
54 #include <asm/sections.h>
55 #include <asm/copro.h>
57 #include <asm/code-patching.h>
58 #include <asm/fadump.h>
59 #include <asm/firmware.h>
61 #include <asm/trace.h>
63 #include <asm/pte-walk.h>
64 #include <asm/asm-prototypes.h>
65 #include <asm/ultravisor.h>
67 #include <mm/mmu_decl.h>
73 #define DBG(fmt...) udbg_printf(fmt)
79 #define DBG_LOW(fmt...) udbg_printf(fmt)
81 #define DBG_LOW(fmt...)
89 * Note: pte --> Linux PTE
90 * HPTE --> PowerPC Hashed Page Table Entry
93 * htab_initialize is called with the MMU off (of course), but
94 * the kernel has been copied down to zero so it can directly
95 * reference global data. At this point it is very difficult
96 * to print debug info.
100 static unsigned long _SDR1;
101 struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];
102 EXPORT_SYMBOL_GPL(mmu_psize_defs);
104 u8 hpte_page_sizes[1 << LP_BITS];
105 EXPORT_SYMBOL_GPL(hpte_page_sizes);
107 struct hash_pte *htab_address;
108 unsigned long htab_size_bytes;
109 unsigned long htab_hash_mask;
110 EXPORT_SYMBOL_GPL(htab_hash_mask);
111 int mmu_linear_psize = MMU_PAGE_4K;
112 EXPORT_SYMBOL_GPL(mmu_linear_psize);
113 int mmu_virtual_psize = MMU_PAGE_4K;
114 int mmu_vmalloc_psize = MMU_PAGE_4K;
115 #ifdef CONFIG_SPARSEMEM_VMEMMAP
116 int mmu_vmemmap_psize = MMU_PAGE_4K;
118 int mmu_io_psize = MMU_PAGE_4K;
119 int mmu_kernel_ssize = MMU_SEGSIZE_256M;
120 EXPORT_SYMBOL_GPL(mmu_kernel_ssize);
121 int mmu_highuser_ssize = MMU_SEGSIZE_256M;
122 u16 mmu_slb_size = 64;
123 EXPORT_SYMBOL_GPL(mmu_slb_size);
124 #ifdef CONFIG_PPC_64K_PAGES
125 int mmu_ci_restrictions;
127 #ifdef CONFIG_DEBUG_PAGEALLOC
128 static u8 *linear_map_hash_slots;
129 static unsigned long linear_map_hash_count;
130 static DEFINE_SPINLOCK(linear_map_hash_lock);
131 #endif /* CONFIG_DEBUG_PAGEALLOC */
132 struct mmu_hash_ops mmu_hash_ops;
133 EXPORT_SYMBOL(mmu_hash_ops);
136 * These are definitions of page sizes arrays to be used when none
137 * is provided by the firmware.
141 * Fallback (4k pages only)
143 static struct mmu_psize_def mmu_psize_defaults[] = {
147 .penc = {[MMU_PAGE_4K] = 0, [1 ... MMU_PAGE_COUNT - 1] = -1},
154 * POWER4, GPUL, POWER5
156 * Support for 16Mb large pages
158 static struct mmu_psize_def mmu_psize_defaults_gp[] = {
162 .penc = {[MMU_PAGE_4K] = 0, [1 ... MMU_PAGE_COUNT - 1] = -1},
169 .penc = {[0 ... MMU_PAGE_16M - 1] = -1, [MMU_PAGE_16M] = 0,
170 [MMU_PAGE_16M + 1 ... MMU_PAGE_COUNT - 1] = -1 },
177 * 'R' and 'C' update notes:
178 * - Under pHyp or KVM, the updatepp path will not set C, thus it *will*
179 * create writeable HPTEs without C set, because the hcall H_PROTECT
180 * that we use in that case will not update C
181 * - The above is however not a problem, because we also don't do that
182 * fancy "no flush" variant of eviction and we use H_REMOVE which will
183 * do the right thing and thus we don't have the race I described earlier
185 * - Under bare metal, we do have the race, so we need R and C set
186 * - We make sure R is always set and never lost
187 * - C is _PAGE_DIRTY, and *should* always be set for a writeable mapping
189 unsigned long htab_convert_pte_flags(unsigned long pteflags)
191 unsigned long rflags = 0;
193 /* _PAGE_EXEC -> NOEXEC */
194 if ((pteflags & _PAGE_EXEC) == 0)
198 * Linux uses slb key 0 for kernel and 1 for user.
199 * kernel RW areas are mapped with PPP=0b000
200 * User area is mapped with PPP=0b010 for read/write
201 * or PPP=0b011 for read-only (including writeable but clean pages).
203 if (pteflags & _PAGE_PRIVILEGED) {
205 * Kernel read only mapped with ppp bits 0b110
207 if (!(pteflags & _PAGE_WRITE)) {
208 if (mmu_has_feature(MMU_FTR_KERNEL_RO))
209 rflags |= (HPTE_R_PP0 | 0x2);
214 if (pteflags & _PAGE_RWX)
216 if (!((pteflags & _PAGE_WRITE) && (pteflags & _PAGE_DIRTY)))
220 * We can't allow hardware to update hpte bits. Hence always
221 * set 'R' bit and set 'C' if it is a write fault
225 if (pteflags & _PAGE_DIRTY)
231 if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_TOLERANT)
233 else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_NON_IDEMPOTENT)
234 rflags |= (HPTE_R_I | HPTE_R_G);
237 * Add memory coherence if cache inhibited is not set
241 rflags |= pte_to_hpte_pkey_bits(pteflags);
245 int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
246 unsigned long pstart, unsigned long prot,
247 int psize, int ssize)
249 unsigned long vaddr, paddr;
250 unsigned int step, shift;
253 shift = mmu_psize_defs[psize].shift;
256 prot = htab_convert_pte_flags(prot);
258 DBG("htab_bolt_mapping(%lx..%lx -> %lx (%lx,%d,%d)\n",
259 vstart, vend, pstart, prot, psize, ssize);
261 for (vaddr = vstart, paddr = pstart; vaddr < vend;
262 vaddr += step, paddr += step) {
263 unsigned long hash, hpteg;
264 unsigned long vsid = get_kernel_vsid(vaddr, ssize);
265 unsigned long vpn = hpt_vpn(vaddr, vsid, ssize);
266 unsigned long tprot = prot;
267 bool secondary_hash = false;
270 * If we hit a bad address return error.
274 /* Make kernel text executable */
275 if (overlaps_kernel_text(vaddr, vaddr + step))
279 * If relocatable, check if it overlaps interrupt vectors that
280 * are copied down to real 0. For relocatable kernel
281 * (e.g. kdump case) we copy interrupt vectors down to real
282 * address 0. Mark that region as executable. This is
283 * because on p8 system with relocation on exception feature
284 * enabled, exceptions are raised with MMU (IR=DR=1) ON. Hence
285 * in order to execute the interrupt handlers in virtual
286 * mode the vector region need to be marked as executable.
288 if ((PHYSICAL_START > MEMORY_START) &&
289 overlaps_interrupt_vector_text(vaddr, vaddr + step))
292 hash = hpt_hash(vpn, shift, ssize);
293 hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
295 BUG_ON(!mmu_hash_ops.hpte_insert);
297 ret = mmu_hash_ops.hpte_insert(hpteg, vpn, paddr, tprot,
298 HPTE_V_BOLTED, psize, psize,
302 * Try to to keep bolted entries in primary.
303 * Remove non bolted entries and try insert again
305 ret = mmu_hash_ops.hpte_remove(hpteg);
307 ret = mmu_hash_ops.hpte_insert(hpteg, vpn, paddr, tprot,
308 HPTE_V_BOLTED, psize, psize,
310 if (ret == -1 && !secondary_hash) {
311 secondary_hash = true;
312 hpteg = ((~hash & htab_hash_mask) * HPTES_PER_GROUP);
321 #ifdef CONFIG_DEBUG_PAGEALLOC
322 if (debug_pagealloc_enabled() &&
323 (paddr >> PAGE_SHIFT) < linear_map_hash_count)
324 linear_map_hash_slots[paddr >> PAGE_SHIFT] = ret | 0x80;
325 #endif /* CONFIG_DEBUG_PAGEALLOC */
327 return ret < 0 ? ret : 0;
330 int htab_remove_mapping(unsigned long vstart, unsigned long vend,
331 int psize, int ssize)
334 unsigned int step, shift;
338 shift = mmu_psize_defs[psize].shift;
341 if (!mmu_hash_ops.hpte_removebolted)
344 for (vaddr = vstart; vaddr < vend; vaddr += step) {
345 rc = mmu_hash_ops.hpte_removebolted(vaddr, psize, ssize);
357 static bool disable_1tb_segments = false;
359 static int __init parse_disable_1tb_segments(char *p)
361 disable_1tb_segments = true;
364 early_param("disable_1tb_segments", parse_disable_1tb_segments);
366 static int __init htab_dt_scan_seg_sizes(unsigned long node,
367 const char *uname, int depth,
370 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
374 /* We are scanning "cpu" nodes only */
375 if (type == NULL || strcmp(type, "cpu") != 0)
378 prop = of_get_flat_dt_prop(node, "ibm,processor-segment-sizes", &size);
381 for (; size >= 4; size -= 4, ++prop) {
382 if (be32_to_cpu(prop[0]) == 40) {
383 DBG("1T segment support detected\n");
385 if (disable_1tb_segments) {
386 DBG("1T segments disabled by command line\n");
390 cur_cpu_spec->mmu_features |= MMU_FTR_1T_SEGMENT;
394 cur_cpu_spec->mmu_features &= ~MMU_FTR_NO_SLBIE_B;
398 static int __init get_idx_from_shift(unsigned int shift)
422 static int __init htab_dt_scan_page_sizes(unsigned long node,
423 const char *uname, int depth,
426 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
430 /* We are scanning "cpu" nodes only */
431 if (type == NULL || strcmp(type, "cpu") != 0)
434 prop = of_get_flat_dt_prop(node, "ibm,segment-page-sizes", &size);
438 pr_info("Page sizes from device-tree:\n");
440 cur_cpu_spec->mmu_features &= ~(MMU_FTR_16M_PAGE);
442 unsigned int base_shift = be32_to_cpu(prop[0]);
443 unsigned int slbenc = be32_to_cpu(prop[1]);
444 unsigned int lpnum = be32_to_cpu(prop[2]);
445 struct mmu_psize_def *def;
448 size -= 3; prop += 3;
449 base_idx = get_idx_from_shift(base_shift);
451 /* skip the pte encoding also */
452 prop += lpnum * 2; size -= lpnum * 2;
455 def = &mmu_psize_defs[base_idx];
456 if (base_idx == MMU_PAGE_16M)
457 cur_cpu_spec->mmu_features |= MMU_FTR_16M_PAGE;
459 def->shift = base_shift;
460 if (base_shift <= 23)
463 def->avpnm = (1 << (base_shift - 23)) - 1;
466 * We don't know for sure what's up with tlbiel, so
467 * for now we only set it for 4K and 64K pages
469 if (base_idx == MMU_PAGE_4K || base_idx == MMU_PAGE_64K)
474 while (size > 0 && lpnum) {
475 unsigned int shift = be32_to_cpu(prop[0]);
476 int penc = be32_to_cpu(prop[1]);
478 prop += 2; size -= 2;
481 idx = get_idx_from_shift(shift);
486 pr_err("Invalid penc for base_shift=%d "
487 "shift=%d\n", base_shift, shift);
489 def->penc[idx] = penc;
490 pr_info("base_shift=%d: shift=%d, sllp=0x%04lx,"
491 " avpnm=0x%08lx, tlbiel=%d, penc=%d\n",
492 base_shift, shift, def->sllp,
493 def->avpnm, def->tlbiel, def->penc[idx]);
500 #ifdef CONFIG_HUGETLB_PAGE
502 * Scan for 16G memory blocks that have been set aside for huge pages
503 * and reserve those blocks for 16G huge pages.
505 static int __init htab_dt_scan_hugepage_blocks(unsigned long node,
506 const char *uname, int depth,
508 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
509 const __be64 *addr_prop;
510 const __be32 *page_count_prop;
511 unsigned int expected_pages;
512 long unsigned int phys_addr;
513 long unsigned int block_size;
515 /* We are scanning "memory" nodes only */
516 if (type == NULL || strcmp(type, "memory") != 0)
520 * This property is the log base 2 of the number of virtual pages that
521 * will represent this memory block.
523 page_count_prop = of_get_flat_dt_prop(node, "ibm,expected#pages", NULL);
524 if (page_count_prop == NULL)
526 expected_pages = (1 << be32_to_cpu(page_count_prop[0]));
527 addr_prop = of_get_flat_dt_prop(node, "reg", NULL);
528 if (addr_prop == NULL)
530 phys_addr = be64_to_cpu(addr_prop[0]);
531 block_size = be64_to_cpu(addr_prop[1]);
532 if (block_size != (16 * GB))
534 printk(KERN_INFO "Huge page(16GB) memory: "
535 "addr = 0x%lX size = 0x%lX pages = %d\n",
536 phys_addr, block_size, expected_pages);
537 if (phys_addr + block_size * expected_pages <= memblock_end_of_DRAM()) {
538 memblock_reserve(phys_addr, block_size * expected_pages);
539 pseries_add_gpage(phys_addr, block_size, expected_pages);
543 #endif /* CONFIG_HUGETLB_PAGE */
545 static void mmu_psize_set_default_penc(void)
548 for (bpsize = 0; bpsize < MMU_PAGE_COUNT; bpsize++)
549 for (apsize = 0; apsize < MMU_PAGE_COUNT; apsize++)
550 mmu_psize_defs[bpsize].penc[apsize] = -1;
553 #ifdef CONFIG_PPC_64K_PAGES
555 static bool might_have_hea(void)
558 * The HEA ethernet adapter requires awareness of the
559 * GX bus. Without that awareness we can easily assume
560 * we will never see an HEA ethernet device.
562 #ifdef CONFIG_IBMEBUS
563 return !cpu_has_feature(CPU_FTR_ARCH_207S) &&
564 firmware_has_feature(FW_FEATURE_SPLPAR);
570 #endif /* #ifdef CONFIG_PPC_64K_PAGES */
572 static void __init htab_scan_page_sizes(void)
576 /* se the invalid penc to -1 */
577 mmu_psize_set_default_penc();
579 /* Default to 4K pages only */
580 memcpy(mmu_psize_defs, mmu_psize_defaults,
581 sizeof(mmu_psize_defaults));
584 * Try to find the available page sizes in the device-tree
586 rc = of_scan_flat_dt(htab_dt_scan_page_sizes, NULL);
587 if (rc == 0 && early_mmu_has_feature(MMU_FTR_16M_PAGE)) {
589 * Nothing in the device-tree, but the CPU supports 16M pages,
590 * so let's fallback on a known size list for 16M capable CPUs.
592 memcpy(mmu_psize_defs, mmu_psize_defaults_gp,
593 sizeof(mmu_psize_defaults_gp));
596 #ifdef CONFIG_HUGETLB_PAGE
597 if (!hugetlb_disabled && !early_radix_enabled() ) {
598 /* Reserve 16G huge page memory sections for huge pages */
599 of_scan_flat_dt(htab_dt_scan_hugepage_blocks, NULL);
601 #endif /* CONFIG_HUGETLB_PAGE */
605 * Fill in the hpte_page_sizes[] array.
606 * We go through the mmu_psize_defs[] array looking for all the
607 * supported base/actual page size combinations. Each combination
608 * has a unique pagesize encoding (penc) value in the low bits of
609 * the LP field of the HPTE. For actual page sizes less than 1MB,
610 * some of the upper LP bits are used for RPN bits, meaning that
611 * we need to fill in several entries in hpte_page_sizes[].
613 * In diagrammatic form, with r = RPN bits and z = page size bits:
614 * PTE LP actual page size
621 * The zzzz bits are implementation-specific but are chosen so that
622 * no encoding for a larger page size uses the same value in its
623 * low-order N bits as the encoding for the 2^(12+N) byte page size
626 static void init_hpte_page_sizes(void)
629 long int shift, penc;
631 for (bp = 0; bp < MMU_PAGE_COUNT; ++bp) {
632 if (!mmu_psize_defs[bp].shift)
633 continue; /* not a supported page size */
634 for (ap = bp; ap < MMU_PAGE_COUNT; ++ap) {
635 penc = mmu_psize_defs[bp].penc[ap];
636 if (penc == -1 || !mmu_psize_defs[ap].shift)
638 shift = mmu_psize_defs[ap].shift - LP_SHIFT;
640 continue; /* should never happen */
642 * For page sizes less than 1MB, this loop
643 * replicates the entry for all possible values
646 while (penc < (1 << LP_BITS)) {
647 hpte_page_sizes[penc] = (ap << 4) | bp;
654 static void __init htab_init_page_sizes(void)
657 init_hpte_page_sizes();
659 if (!debug_pagealloc_enabled()) {
661 * Pick a size for the linear mapping. Currently, we only
662 * support 16M, 1M and 4K which is the default
664 if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) &&
665 (unsigned long)_stext % 0x1000000) {
666 if (mmu_psize_defs[MMU_PAGE_16M].shift)
667 pr_warn("Kernel not 16M aligned, disabling 16M linear map alignment\n");
671 if (mmu_psize_defs[MMU_PAGE_16M].shift && aligned)
672 mmu_linear_psize = MMU_PAGE_16M;
673 else if (mmu_psize_defs[MMU_PAGE_1M].shift)
674 mmu_linear_psize = MMU_PAGE_1M;
677 #ifdef CONFIG_PPC_64K_PAGES
679 * Pick a size for the ordinary pages. Default is 4K, we support
680 * 64K for user mappings and vmalloc if supported by the processor.
681 * We only use 64k for ioremap if the processor
682 * (and firmware) support cache-inhibited large pages.
683 * If not, we use 4k and set mmu_ci_restrictions so that
684 * hash_page knows to switch processes that use cache-inhibited
685 * mappings to 4k pages.
687 if (mmu_psize_defs[MMU_PAGE_64K].shift) {
688 mmu_virtual_psize = MMU_PAGE_64K;
689 mmu_vmalloc_psize = MMU_PAGE_64K;
690 if (mmu_linear_psize == MMU_PAGE_4K)
691 mmu_linear_psize = MMU_PAGE_64K;
692 if (mmu_has_feature(MMU_FTR_CI_LARGE_PAGE)) {
694 * When running on pSeries using 64k pages for ioremap
695 * would stop us accessing the HEA ethernet. So if we
696 * have the chance of ever seeing one, stay at 4k.
698 if (!might_have_hea())
699 mmu_io_psize = MMU_PAGE_64K;
701 mmu_ci_restrictions = 1;
703 #endif /* CONFIG_PPC_64K_PAGES */
705 #ifdef CONFIG_SPARSEMEM_VMEMMAP
707 * We try to use 16M pages for vmemmap if that is supported
708 * and we have at least 1G of RAM at boot
710 if (mmu_psize_defs[MMU_PAGE_16M].shift &&
711 memblock_phys_mem_size() >= 0x40000000)
712 mmu_vmemmap_psize = MMU_PAGE_16M;
714 mmu_vmemmap_psize = mmu_virtual_psize;
715 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
717 printk(KERN_DEBUG "Page orders: linear mapping = %d, "
718 "virtual = %d, io = %d"
719 #ifdef CONFIG_SPARSEMEM_VMEMMAP
723 mmu_psize_defs[mmu_linear_psize].shift,
724 mmu_psize_defs[mmu_virtual_psize].shift,
725 mmu_psize_defs[mmu_io_psize].shift
726 #ifdef CONFIG_SPARSEMEM_VMEMMAP
727 ,mmu_psize_defs[mmu_vmemmap_psize].shift
732 static int __init htab_dt_scan_pftsize(unsigned long node,
733 const char *uname, int depth,
736 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
739 /* We are scanning "cpu" nodes only */
740 if (type == NULL || strcmp(type, "cpu") != 0)
743 prop = of_get_flat_dt_prop(node, "ibm,pft-size", NULL);
745 /* pft_size[0] is the NUMA CEC cookie */
746 ppc64_pft_size = be32_to_cpu(prop[1]);
752 unsigned htab_shift_for_mem_size(unsigned long mem_size)
754 unsigned memshift = __ilog2(mem_size);
755 unsigned pshift = mmu_psize_defs[mmu_virtual_psize].shift;
758 /* round mem_size up to next power of 2 */
759 if ((1UL << memshift) < mem_size)
762 /* aim for 2 pages / pteg */
763 pteg_shift = memshift - (pshift + 1);
766 * 2^11 PTEGS of 128 bytes each, ie. 2^18 bytes is the minimum htab
767 * size permitted by the architecture.
769 return max(pteg_shift + 7, 18U);
772 static unsigned long __init htab_get_table_size(void)
775 * If hash size isn't already provided by the platform, we try to
776 * retrieve it from the device-tree. If it's not there neither, we
777 * calculate it now based on the total RAM size
779 if (ppc64_pft_size == 0)
780 of_scan_flat_dt(htab_dt_scan_pftsize, NULL);
782 return 1UL << ppc64_pft_size;
784 return 1UL << htab_shift_for_mem_size(memblock_phys_mem_size());
787 #ifdef CONFIG_MEMORY_HOTPLUG
788 static int resize_hpt_for_hotplug(unsigned long new_mem_size)
790 unsigned target_hpt_shift;
792 if (!mmu_hash_ops.resize_hpt)
795 target_hpt_shift = htab_shift_for_mem_size(new_mem_size);
798 * To avoid lots of HPT resizes if memory size is fluctuating
799 * across a boundary, we deliberately have some hysterisis
800 * here: we immediately increase the HPT size if the target
801 * shift exceeds the current shift, but we won't attempt to
802 * reduce unless the target shift is at least 2 below the
805 if (target_hpt_shift > ppc64_pft_size ||
806 target_hpt_shift < ppc64_pft_size - 1)
807 return mmu_hash_ops.resize_hpt(target_hpt_shift);
812 int hash__create_section_mapping(unsigned long start, unsigned long end,
813 int nid, pgprot_t prot)
817 if (end >= H_VMALLOC_START) {
818 pr_warn("Outside the supported range\n");
822 resize_hpt_for_hotplug(memblock_phys_mem_size());
824 rc = htab_bolt_mapping(start, end, __pa(start),
825 pgprot_val(prot), mmu_linear_psize,
829 int rc2 = htab_remove_mapping(start, end, mmu_linear_psize,
831 BUG_ON(rc2 && (rc2 != -ENOENT));
836 int hash__remove_section_mapping(unsigned long start, unsigned long end)
838 int rc = htab_remove_mapping(start, end, mmu_linear_psize,
842 if (resize_hpt_for_hotplug(memblock_phys_mem_size()) == -ENOSPC)
843 pr_warn("Hash collision while resizing HPT\n");
847 #endif /* CONFIG_MEMORY_HOTPLUG */
849 static void __init hash_init_partition_table(phys_addr_t hash_table,
850 unsigned long htab_size)
852 mmu_partition_table_init();
855 * PS field (VRMA page size) is not used for LPID 0, hence set to 0.
856 * For now, UPRT is 0 and we have no segment table.
858 htab_size = __ilog2(htab_size) - 18;
859 mmu_partition_table_set_entry(0, hash_table | htab_size, 0, false);
860 pr_info("Partition table %p\n", partition_tb);
863 static void __init htab_initialize(void)
866 unsigned long pteg_count;
868 unsigned long base = 0, size = 0;
869 struct memblock_region *reg;
871 DBG(" -> htab_initialize()\n");
873 if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) {
874 mmu_kernel_ssize = MMU_SEGSIZE_1T;
875 mmu_highuser_ssize = MMU_SEGSIZE_1T;
876 printk(KERN_INFO "Using 1TB segments\n");
879 if (stress_slb_enabled)
880 static_branch_enable(&stress_slb_key);
883 * Calculate the required size of the htab. We want the number of
884 * PTEGs to equal one half the number of real pages.
886 htab_size_bytes = htab_get_table_size();
887 pteg_count = htab_size_bytes >> 7;
889 htab_hash_mask = pteg_count - 1;
891 if (firmware_has_feature(FW_FEATURE_LPAR) ||
892 firmware_has_feature(FW_FEATURE_PS3_LV1)) {
893 /* Using a hypervisor which owns the htab */
896 #ifdef CONFIG_FA_DUMP
898 * If firmware assisted dump is active firmware preserves
899 * the contents of htab along with entire partition memory.
900 * Clear the htab if firmware assisted dump is active so
901 * that we dont end up using old mappings.
903 if (is_fadump_active() && mmu_hash_ops.hpte_clear_all)
904 mmu_hash_ops.hpte_clear_all();
907 unsigned long limit = MEMBLOCK_ALLOC_ANYWHERE;
909 #ifdef CONFIG_PPC_CELL
911 * Cell may require the hash table down low when using the
912 * Axon IOMMU in order to fit the dynamic region over it, see
913 * comments in cell/iommu.c
915 if (fdt_subnode_offset(initial_boot_params, 0, "axon") > 0) {
917 pr_info("Hash table forced below 2G for Axon IOMMU\n");
919 #endif /* CONFIG_PPC_CELL */
921 table = memblock_phys_alloc_range(htab_size_bytes,
925 panic("ERROR: Failed to allocate %pa bytes below %pa\n",
926 &htab_size_bytes, &limit);
928 DBG("Hash table allocated at %lx, size: %lx\n", table,
931 htab_address = __va(table);
933 /* htab absolute addr + encoded htabsize */
934 _SDR1 = table + __ilog2(htab_size_bytes) - 18;
936 /* Initialize the HPT with no entries */
937 memset((void *)table, 0, htab_size_bytes);
939 if (!cpu_has_feature(CPU_FTR_ARCH_300))
941 mtspr(SPRN_SDR1, _SDR1);
943 hash_init_partition_table(table, htab_size_bytes);
946 prot = pgprot_val(PAGE_KERNEL);
948 #ifdef CONFIG_DEBUG_PAGEALLOC
949 if (debug_pagealloc_enabled()) {
950 linear_map_hash_count = memblock_end_of_DRAM() >> PAGE_SHIFT;
951 linear_map_hash_slots = memblock_alloc_try_nid(
952 linear_map_hash_count, 1, MEMBLOCK_LOW_LIMIT,
953 ppc64_rma_size, NUMA_NO_NODE);
954 if (!linear_map_hash_slots)
955 panic("%s: Failed to allocate %lu bytes max_addr=%pa\n",
956 __func__, linear_map_hash_count, &ppc64_rma_size);
958 #endif /* CONFIG_DEBUG_PAGEALLOC */
960 /* create bolted the linear mapping in the hash table */
961 for_each_memblock(memory, reg) {
962 base = (unsigned long)__va(reg->base);
965 DBG("creating mapping for region: %lx..%lx (prot: %lx)\n",
968 if ((base + size) >= H_VMALLOC_START) {
969 pr_warn("Outside the supported range\n");
973 BUG_ON(htab_bolt_mapping(base, base + size, __pa(base),
974 prot, mmu_linear_psize, mmu_kernel_ssize));
976 memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
979 * If we have a memory_limit and we've allocated TCEs then we need to
980 * explicitly map the TCE area at the top of RAM. We also cope with the
981 * case that the TCEs start below memory_limit.
982 * tce_alloc_start/end are 16MB aligned so the mapping should work
983 * for either 4K or 16MB pages.
985 if (tce_alloc_start) {
986 tce_alloc_start = (unsigned long)__va(tce_alloc_start);
987 tce_alloc_end = (unsigned long)__va(tce_alloc_end);
989 if (base + size >= tce_alloc_start)
990 tce_alloc_start = base + size + 1;
992 BUG_ON(htab_bolt_mapping(tce_alloc_start, tce_alloc_end,
993 __pa(tce_alloc_start), prot,
994 mmu_linear_psize, mmu_kernel_ssize));
998 DBG(" <- htab_initialize()\n");
1003 void __init hash__early_init_devtree(void)
1005 /* Initialize segment sizes */
1006 of_scan_flat_dt(htab_dt_scan_seg_sizes, NULL);
1008 /* Initialize page sizes */
1009 htab_scan_page_sizes();
1012 static struct hash_mm_context init_hash_mm_context;
1013 void __init hash__early_init_mmu(void)
1015 #ifndef CONFIG_PPC_64K_PAGES
1017 * We have code in __hash_page_4K() and elsewhere, which assumes it can
1019 * new_pte |= (slot << H_PAGE_F_GIX_SHIFT) & (H_PAGE_F_SECOND | H_PAGE_F_GIX);
1021 * Where the slot number is between 0-15, and values of 8-15 indicate
1022 * the secondary bucket. For that code to work H_PAGE_F_SECOND and
1023 * H_PAGE_F_GIX must occupy four contiguous bits in the PTE, and
1024 * H_PAGE_F_SECOND must be placed above H_PAGE_F_GIX. Assert that here
1025 * with a BUILD_BUG_ON().
1027 BUILD_BUG_ON(H_PAGE_F_SECOND != (1ul << (H_PAGE_F_GIX_SHIFT + 3)));
1028 #endif /* CONFIG_PPC_64K_PAGES */
1030 htab_init_page_sizes();
1033 * initialize page table size
1035 __pte_frag_nr = H_PTE_FRAG_NR;
1036 __pte_frag_size_shift = H_PTE_FRAG_SIZE_SHIFT;
1037 __pmd_frag_nr = H_PMD_FRAG_NR;
1038 __pmd_frag_size_shift = H_PMD_FRAG_SIZE_SHIFT;
1040 __pte_index_size = H_PTE_INDEX_SIZE;
1041 __pmd_index_size = H_PMD_INDEX_SIZE;
1042 __pud_index_size = H_PUD_INDEX_SIZE;
1043 __pgd_index_size = H_PGD_INDEX_SIZE;
1044 __pud_cache_index = H_PUD_CACHE_INDEX;
1045 __pte_table_size = H_PTE_TABLE_SIZE;
1046 __pmd_table_size = H_PMD_TABLE_SIZE;
1047 __pud_table_size = H_PUD_TABLE_SIZE;
1048 __pgd_table_size = H_PGD_TABLE_SIZE;
1050 * 4k use hugepd format, so for hash set then to
1053 __pmd_val_bits = HASH_PMD_VAL_BITS;
1054 __pud_val_bits = HASH_PUD_VAL_BITS;
1055 __pgd_val_bits = HASH_PGD_VAL_BITS;
1057 __kernel_virt_start = H_KERN_VIRT_START;
1058 __vmalloc_start = H_VMALLOC_START;
1059 __vmalloc_end = H_VMALLOC_END;
1060 __kernel_io_start = H_KERN_IO_START;
1061 __kernel_io_end = H_KERN_IO_END;
1062 vmemmap = (struct page *)H_VMEMMAP_START;
1063 ioremap_bot = IOREMAP_BASE;
1066 pci_io_base = ISA_IO_BASE;
1069 /* Select appropriate backend */
1070 if (firmware_has_feature(FW_FEATURE_PS3_LV1))
1071 ps3_early_mm_init();
1072 else if (firmware_has_feature(FW_FEATURE_LPAR))
1073 hpte_init_pseries();
1074 else if (IS_ENABLED(CONFIG_PPC_NATIVE))
1077 if (!mmu_hash_ops.hpte_insert)
1078 panic("hash__early_init_mmu: No MMU hash ops defined!\n");
1081 * Initialize the MMU Hash table and create the linear mapping
1082 * of memory. Has to be done before SLB initialization as this is
1083 * currently where the page size encoding is obtained.
1087 init_mm.context.hash_context = &init_hash_mm_context;
1088 mm_ctx_set_slb_addr_limit(&init_mm.context, SLB_ADDR_LIMIT_DEFAULT);
1090 pr_info("Initializing hash mmu with SLB\n");
1091 /* Initialize SLB management */
1094 if (cpu_has_feature(CPU_FTR_ARCH_206)
1095 && cpu_has_feature(CPU_FTR_HVMODE))
1100 void hash__early_init_mmu_secondary(void)
1102 /* Initialize hash table for that CPU */
1103 if (!firmware_has_feature(FW_FEATURE_LPAR)) {
1105 if (!cpu_has_feature(CPU_FTR_ARCH_300))
1106 mtspr(SPRN_SDR1, _SDR1);
1108 set_ptcr_when_no_uv(__pa(partition_tb) |
1109 (PATB_SIZE_SHIFT - 12));
1111 /* Initialize SLB */
1114 if (cpu_has_feature(CPU_FTR_ARCH_206)
1115 && cpu_has_feature(CPU_FTR_HVMODE))
1118 #ifdef CONFIG_PPC_MEM_KEYS
1119 if (mmu_has_feature(MMU_FTR_PKEY))
1120 mtspr(SPRN_UAMOR, default_uamor);
1123 #endif /* CONFIG_SMP */
1126 * Called by asm hashtable.S for doing lazy icache flush
1128 unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap)
1132 if (!pfn_valid(pte_pfn(pte)))
1135 page = pte_page(pte);
1138 if (!test_bit(PG_arch_1, &page->flags) && !PageReserved(page)) {
1139 if (trap == 0x400) {
1140 flush_dcache_icache_page(page);
1141 set_bit(PG_arch_1, &page->flags);
1148 #ifdef CONFIG_PPC_MM_SLICES
1149 static unsigned int get_paca_psize(unsigned long addr)
1151 unsigned char *psizes;
1152 unsigned long index, mask_index;
1154 if (addr < SLICE_LOW_TOP) {
1155 psizes = get_paca()->mm_ctx_low_slices_psize;
1156 index = GET_LOW_SLICE_INDEX(addr);
1158 psizes = get_paca()->mm_ctx_high_slices_psize;
1159 index = GET_HIGH_SLICE_INDEX(addr);
1161 mask_index = index & 0x1;
1162 return (psizes[index >> 1] >> (mask_index * 4)) & 0xF;
1166 unsigned int get_paca_psize(unsigned long addr)
1168 return get_paca()->mm_ctx_user_psize;
1173 * Demote a segment to using 4k pages.
1174 * For now this makes the whole process use 4k pages.
1176 #ifdef CONFIG_PPC_64K_PAGES
1177 void demote_segment_4k(struct mm_struct *mm, unsigned long addr)
1179 if (get_slice_psize(mm, addr) == MMU_PAGE_4K)
1181 slice_set_range_psize(mm, addr, 1, MMU_PAGE_4K);
1182 copro_flush_all_slbs(mm);
1183 if ((get_paca_psize(addr) != MMU_PAGE_4K) && (current->mm == mm)) {
1185 copy_mm_to_paca(mm);
1186 slb_flush_and_restore_bolted();
1189 #endif /* CONFIG_PPC_64K_PAGES */
1191 #ifdef CONFIG_PPC_SUBPAGE_PROT
1193 * This looks up a 2-bit protection code for a 4k subpage of a 64k page.
1194 * Userspace sets the subpage permissions using the subpage_prot system call.
1196 * Result is 0: full permissions, _PAGE_RW: read-only,
1197 * _PAGE_RWX: no access.
1199 static int subpage_protection(struct mm_struct *mm, unsigned long ea)
1201 struct subpage_prot_table *spt = mm_ctx_subpage_prot(&mm->context);
1208 if (ea >= spt->maxaddr)
1210 if (ea < 0x100000000UL) {
1211 /* addresses below 4GB use spt->low_prot */
1212 sbpm = spt->low_prot;
1214 sbpm = spt->protptrs[ea >> SBP_L3_SHIFT];
1218 sbpp = sbpm[(ea >> SBP_L2_SHIFT) & (SBP_L2_COUNT - 1)];
1221 spp = sbpp[(ea >> PAGE_SHIFT) & (SBP_L1_COUNT - 1)];
1223 /* extract 2-bit bitfield for this 4k subpage */
1224 spp >>= 30 - 2 * ((ea >> 12) & 0xf);
1227 * 0 -> full premission
1230 * We return the flag that need to be cleared.
1232 spp = ((spp & 2) ? _PAGE_RWX : 0) | ((spp & 1) ? _PAGE_WRITE : 0);
1236 #else /* CONFIG_PPC_SUBPAGE_PROT */
1237 static inline int subpage_protection(struct mm_struct *mm, unsigned long ea)
1243 void hash_failure_debug(unsigned long ea, unsigned long access,
1244 unsigned long vsid, unsigned long trap,
1245 int ssize, int psize, int lpsize, unsigned long pte)
1247 if (!printk_ratelimit())
1249 pr_info("mm: Hashing failure ! EA=0x%lx access=0x%lx current=%s\n",
1250 ea, access, current->comm);
1251 pr_info(" trap=0x%lx vsid=0x%lx ssize=%d base psize=%d psize %d pte=0x%lx\n",
1252 trap, vsid, ssize, psize, lpsize, pte);
1255 static void check_paca_psize(unsigned long ea, struct mm_struct *mm,
1256 int psize, bool user_region)
1259 if (psize != get_paca_psize(ea)) {
1260 copy_mm_to_paca(mm);
1261 slb_flush_and_restore_bolted();
1263 } else if (get_paca()->vmalloc_sllp !=
1264 mmu_psize_defs[mmu_vmalloc_psize].sllp) {
1265 get_paca()->vmalloc_sllp =
1266 mmu_psize_defs[mmu_vmalloc_psize].sllp;
1267 slb_vmalloc_update();
1274 * 1 - normal page fault
1275 * -1 - critical hash insertion error
1276 * -2 - access not permitted by subpage protection mechanism
1278 int hash_page_mm(struct mm_struct *mm, unsigned long ea,
1279 unsigned long access, unsigned long trap,
1280 unsigned long flags)
1283 enum ctx_state prev_state = exception_enter();
1288 int rc, user_region = 0;
1291 DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n",
1293 trace_hash_fault(ea, access, trap);
1295 /* Get region & vsid */
1296 switch (get_region_id(ea)) {
1297 case USER_REGION_ID:
1300 DBG_LOW(" user region with no mm !\n");
1304 psize = get_slice_psize(mm, ea);
1305 ssize = user_segment_size(ea);
1306 vsid = get_user_vsid(&mm->context, ea, ssize);
1308 case VMALLOC_REGION_ID:
1309 vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
1310 psize = mmu_vmalloc_psize;
1311 ssize = mmu_kernel_ssize;
1315 vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
1316 psize = mmu_io_psize;
1317 ssize = mmu_kernel_ssize;
1322 * Send the problem up to do_page_fault()
1327 DBG_LOW(" mm=%p, mm->pgdir=%p, vsid=%016lx\n", mm, mm->pgd, vsid);
1331 DBG_LOW("Bad address!\n");
1337 if (pgdir == NULL) {
1342 /* Check CPU locality */
1343 if (user_region && mm_is_thread_local(mm))
1344 flags |= HPTE_LOCAL_UPDATE;
1346 #ifndef CONFIG_PPC_64K_PAGES
1348 * If we use 4K pages and our psize is not 4K, then we might
1349 * be hitting a special driver mapping, and need to align the
1350 * address before we fetch the PTE.
1352 * It could also be a hugepage mapping, in which case this is
1353 * not necessary, but it's not harmful, either.
1355 if (psize != MMU_PAGE_4K)
1356 ea &= ~((1ul << mmu_psize_defs[psize].shift) - 1);
1357 #endif /* CONFIG_PPC_64K_PAGES */
1359 /* Get PTE and page size from page tables */
1360 ptep = find_linux_pte(pgdir, ea, &is_thp, &hugeshift);
1361 if (ptep == NULL || !pte_present(*ptep)) {
1362 DBG_LOW(" no PTE !\n");
1368 * Add _PAGE_PRESENT to the required access perm. If there are parallel
1369 * updates to the pte that can possibly clear _PAGE_PTE, catch that too.
1371 * We can safely use the return pte address in rest of the function
1372 * because we do set H_PAGE_BUSY which prevents further updates to pte
1373 * from generic code.
1375 access |= _PAGE_PRESENT | _PAGE_PTE;
1378 * Pre-check access permissions (will be re-checked atomically
1379 * in __hash_page_XX but this pre-check is a fast path
1381 if (!check_pte_access(access, pte_val(*ptep))) {
1382 DBG_LOW(" no access !\n");
1389 rc = __hash_page_thp(ea, access, vsid, (pmd_t *)ptep,
1390 trap, flags, ssize, psize);
1391 #ifdef CONFIG_HUGETLB_PAGE
1393 rc = __hash_page_huge(ea, access, vsid, ptep, trap,
1394 flags, ssize, hugeshift, psize);
1398 * if we have hugeshift, and is not transhuge with
1399 * hugetlb disabled, something is really wrong.
1405 if (current->mm == mm)
1406 check_paca_psize(ea, mm, psize, user_region);
1411 #ifndef CONFIG_PPC_64K_PAGES
1412 DBG_LOW(" i-pte: %016lx\n", pte_val(*ptep));
1414 DBG_LOW(" i-pte: %016lx %016lx\n", pte_val(*ptep),
1415 pte_val(*(ptep + PTRS_PER_PTE)));
1417 /* Do actual hashing */
1418 #ifdef CONFIG_PPC_64K_PAGES
1419 /* If H_PAGE_4K_PFN is set, make sure this is a 4k segment */
1420 if ((pte_val(*ptep) & H_PAGE_4K_PFN) && psize == MMU_PAGE_64K) {
1421 demote_segment_4k(mm, ea);
1422 psize = MMU_PAGE_4K;
1426 * If this PTE is non-cacheable and we have restrictions on
1427 * using non cacheable large pages, then we switch to 4k
1429 if (mmu_ci_restrictions && psize == MMU_PAGE_64K && pte_ci(*ptep)) {
1431 demote_segment_4k(mm, ea);
1432 psize = MMU_PAGE_4K;
1433 } else if (ea < VMALLOC_END) {
1435 * some driver did a non-cacheable mapping
1436 * in vmalloc space, so switch vmalloc
1439 printk(KERN_ALERT "Reducing vmalloc segment "
1440 "to 4kB pages because of "
1441 "non-cacheable mapping\n");
1442 psize = mmu_vmalloc_psize = MMU_PAGE_4K;
1443 copro_flush_all_slbs(mm);
1447 #endif /* CONFIG_PPC_64K_PAGES */
1449 if (current->mm == mm)
1450 check_paca_psize(ea, mm, psize, user_region);
1452 #ifdef CONFIG_PPC_64K_PAGES
1453 if (psize == MMU_PAGE_64K)
1454 rc = __hash_page_64K(ea, access, vsid, ptep, trap,
1457 #endif /* CONFIG_PPC_64K_PAGES */
1459 int spp = subpage_protection(mm, ea);
1463 rc = __hash_page_4K(ea, access, vsid, ptep, trap,
1468 * Dump some info in case of hash insertion failure, they should
1469 * never happen so it is really useful to know if/when they do
1472 hash_failure_debug(ea, access, vsid, trap, ssize, psize,
1473 psize, pte_val(*ptep));
1474 #ifndef CONFIG_PPC_64K_PAGES
1475 DBG_LOW(" o-pte: %016lx\n", pte_val(*ptep));
1477 DBG_LOW(" o-pte: %016lx %016lx\n", pte_val(*ptep),
1478 pte_val(*(ptep + PTRS_PER_PTE)));
1480 DBG_LOW(" -> rc=%d\n", rc);
1483 exception_exit(prev_state);
1486 EXPORT_SYMBOL_GPL(hash_page_mm);
1488 int hash_page(unsigned long ea, unsigned long access, unsigned long trap,
1489 unsigned long dsisr)
1491 unsigned long flags = 0;
1492 struct mm_struct *mm = current->mm;
1494 if ((get_region_id(ea) == VMALLOC_REGION_ID) ||
1495 (get_region_id(ea) == IO_REGION_ID))
1498 if (dsisr & DSISR_NOHPTE)
1499 flags |= HPTE_NOHPTE_UPDATE;
1501 return hash_page_mm(mm, ea, access, trap, flags);
1503 EXPORT_SYMBOL_GPL(hash_page);
1505 int __hash_page(unsigned long trap, unsigned long ea, unsigned long dsisr,
1508 unsigned long access = _PAGE_PRESENT | _PAGE_READ;
1509 unsigned long flags = 0;
1510 struct mm_struct *mm = current->mm;
1511 unsigned int region_id = get_region_id(ea);
1513 if ((region_id == VMALLOC_REGION_ID) || (region_id == IO_REGION_ID))
1516 if (dsisr & DSISR_NOHPTE)
1517 flags |= HPTE_NOHPTE_UPDATE;
1519 if (dsisr & DSISR_ISSTORE)
1520 access |= _PAGE_WRITE;
1522 * We set _PAGE_PRIVILEGED only when
1523 * kernel mode access kernel space.
1525 * _PAGE_PRIVILEGED is NOT set
1526 * 1) when kernel mode access user space
1527 * 2) user space access kernel space.
1529 access |= _PAGE_PRIVILEGED;
1530 if ((msr & MSR_PR) || (region_id == USER_REGION_ID))
1531 access &= ~_PAGE_PRIVILEGED;
1534 access |= _PAGE_EXEC;
1536 return hash_page_mm(mm, ea, access, trap, flags);
1539 #ifdef CONFIG_PPC_MM_SLICES
1540 static bool should_hash_preload(struct mm_struct *mm, unsigned long ea)
1542 int psize = get_slice_psize(mm, ea);
1544 /* We only prefault standard pages for now */
1545 if (unlikely(psize != mm_ctx_user_psize(&mm->context)))
1549 * Don't prefault if subpage protection is enabled for the EA.
1551 if (unlikely((psize == MMU_PAGE_4K) && subpage_protection(mm, ea)))
1557 static bool should_hash_preload(struct mm_struct *mm, unsigned long ea)
1563 static void hash_preload(struct mm_struct *mm, pte_t *ptep, unsigned long ea,
1564 bool is_exec, unsigned long trap)
1568 int rc, ssize, update_flags = 0;
1569 unsigned long access = _PAGE_PRESENT | _PAGE_READ | (is_exec ? _PAGE_EXEC : 0);
1570 unsigned long flags;
1572 BUG_ON(get_region_id(ea) != USER_REGION_ID);
1574 if (!should_hash_preload(mm, ea))
1577 DBG_LOW("hash_preload(mm=%p, mm->pgdir=%p, ea=%016lx, access=%lx,"
1578 " trap=%lx\n", mm, mm->pgd, ea, access, trap);
1580 /* Get Linux PTE if available */
1586 ssize = user_segment_size(ea);
1587 vsid = get_user_vsid(&mm->context, ea, ssize);
1591 #ifdef CONFIG_PPC_64K_PAGES
1592 /* If either H_PAGE_4K_PFN or cache inhibited is set (and we are on
1593 * a 64K kernel), then we don't preload, hash_page() will take
1594 * care of it once we actually try to access the page.
1595 * That way we don't have to duplicate all of the logic for segment
1596 * page size demotion here
1597 * Called with PTL held, hence can be sure the value won't change in
1600 if ((pte_val(*ptep) & H_PAGE_4K_PFN) || pte_ci(*ptep))
1602 #endif /* CONFIG_PPC_64K_PAGES */
1605 * __hash_page_* must run with interrupts off, as it sets the
1606 * H_PAGE_BUSY bit. It's possible for perf interrupts to hit at any
1607 * time and may take a hash fault reading the user stack, see
1608 * read_user_stack_slow() in the powerpc/perf code.
1610 * If that takes a hash fault on the same page as we lock here, it
1611 * will bail out when seeing H_PAGE_BUSY set, and retry the access
1612 * leading to an infinite loop.
1614 * Disabling interrupts here does not prevent perf interrupts, but it
1615 * will prevent them taking hash faults (see the NMI test in
1616 * do_hash_page), then read_user_stack's copy_from_user_nofault will
1617 * fail and perf will fall back to read_user_stack_slow(), which
1618 * walks the Linux page tables.
1620 * Interrupts must also be off for the duration of the
1621 * mm_is_thread_local test and update, to prevent preempt running the
1622 * mm on another CPU (XXX: this may be racy vs kthread_use_mm).
1624 local_irq_save(flags);
1626 /* Is that local to this CPU ? */
1627 if (mm_is_thread_local(mm))
1628 update_flags |= HPTE_LOCAL_UPDATE;
1631 #ifdef CONFIG_PPC_64K_PAGES
1632 if (mm_ctx_user_psize(&mm->context) == MMU_PAGE_64K)
1633 rc = __hash_page_64K(ea, access, vsid, ptep, trap,
1634 update_flags, ssize);
1636 #endif /* CONFIG_PPC_64K_PAGES */
1637 rc = __hash_page_4K(ea, access, vsid, ptep, trap, update_flags,
1638 ssize, subpage_protection(mm, ea));
1640 /* Dump some info in case of hash insertion failure, they should
1641 * never happen so it is really useful to know if/when they do
1644 hash_failure_debug(ea, access, vsid, trap, ssize,
1645 mm_ctx_user_psize(&mm->context),
1646 mm_ctx_user_psize(&mm->context),
1649 local_irq_restore(flags);
1653 * This is called at the end of handling a user page fault, when the
1654 * fault has been handled by updating a PTE in the linux page tables.
1655 * We use it to preload an HPTE into the hash table corresponding to
1656 * the updated linux PTE.
1658 * This must always be called with the pte lock held.
1660 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
1664 * We don't need to worry about _PAGE_PRESENT here because we are
1665 * called with either mm->page_table_lock held or ptl lock held
1670 if (radix_enabled())
1673 /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
1674 if (!pte_young(*ptep) || address >= TASK_SIZE)
1678 * We try to figure out if we are coming from an instruction
1679 * access fault and pass that down to __hash_page so we avoid
1680 * double-faulting on execution of fresh text. We have to test
1681 * for regs NULL since init will get here first thing at boot.
1683 * We also avoid filling the hash if not coming from a fault.
1686 trap = current->thread.regs ? TRAP(current->thread.regs) : 0UL;
1698 hash_preload(vma->vm_mm, ptep, address, is_exec, trap);
1701 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1702 static inline void tm_flush_hash_page(int local)
1705 * Transactions are not aborted by tlbiel, only tlbie. Without, syncing a
1706 * page back to a block device w/PIO could pick up transactional data
1707 * (bad!) so we force an abort here. Before the sync the page will be
1708 * made read-only, which will flush_hash_page. BIG ISSUE here: if the
1709 * kernel uses a page from userspace without unmapping it first, it may
1710 * see the speculated version.
1712 if (local && cpu_has_feature(CPU_FTR_TM) && current->thread.regs &&
1713 MSR_TM_ACTIVE(current->thread.regs->msr)) {
1715 tm_abort(TM_CAUSE_TLBI);
1719 static inline void tm_flush_hash_page(int local)
1725 * Return the global hash slot, corresponding to the given PTE, which contains
1728 unsigned long pte_get_hash_gslot(unsigned long vpn, unsigned long shift,
1729 int ssize, real_pte_t rpte, unsigned int subpg_index)
1731 unsigned long hash, gslot, hidx;
1733 hash = hpt_hash(vpn, shift, ssize);
1734 hidx = __rpte_to_hidx(rpte, subpg_index);
1735 if (hidx & _PTEIDX_SECONDARY)
1737 gslot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1738 gslot += hidx & _PTEIDX_GROUP_IX;
1742 void flush_hash_page(unsigned long vpn, real_pte_t pte, int psize, int ssize,
1743 unsigned long flags)
1745 unsigned long index, shift, gslot;
1746 int local = flags & HPTE_LOCAL_UPDATE;
1748 DBG_LOW("flush_hash_page(vpn=%016lx)\n", vpn);
1749 pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
1750 gslot = pte_get_hash_gslot(vpn, shift, ssize, pte, index);
1751 DBG_LOW(" sub %ld: gslot=%lx\n", index, gslot);
1753 * We use same base page size and actual psize, because we don't
1754 * use these functions for hugepage
1756 mmu_hash_ops.hpte_invalidate(gslot, vpn, psize, psize,
1758 } pte_iterate_hashed_end();
1760 tm_flush_hash_page(local);
1763 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1764 void flush_hash_hugepage(unsigned long vsid, unsigned long addr,
1765 pmd_t *pmdp, unsigned int psize, int ssize,
1766 unsigned long flags)
1768 int i, max_hpte_count, valid;
1769 unsigned long s_addr;
1770 unsigned char *hpte_slot_array;
1771 unsigned long hidx, shift, vpn, hash, slot;
1772 int local = flags & HPTE_LOCAL_UPDATE;
1774 s_addr = addr & HPAGE_PMD_MASK;
1775 hpte_slot_array = get_hpte_slot_array(pmdp);
1777 * IF we try to do a HUGE PTE update after a withdraw is done.
1778 * we will find the below NULL. This happens when we do
1781 if (!hpte_slot_array)
1784 if (mmu_hash_ops.hugepage_invalidate) {
1785 mmu_hash_ops.hugepage_invalidate(vsid, s_addr, hpte_slot_array,
1786 psize, ssize, local);
1790 * No bluk hpte removal support, invalidate each entry
1792 shift = mmu_psize_defs[psize].shift;
1793 max_hpte_count = HPAGE_PMD_SIZE >> shift;
1794 for (i = 0; i < max_hpte_count; i++) {
1796 * 8 bits per each hpte entries
1797 * 000| [ secondary group (one bit) | hidx (3 bits) | valid bit]
1799 valid = hpte_valid(hpte_slot_array, i);
1802 hidx = hpte_hash_index(hpte_slot_array, i);
1805 addr = s_addr + (i * (1ul << shift));
1806 vpn = hpt_vpn(addr, vsid, ssize);
1807 hash = hpt_hash(vpn, shift, ssize);
1808 if (hidx & _PTEIDX_SECONDARY)
1811 slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1812 slot += hidx & _PTEIDX_GROUP_IX;
1813 mmu_hash_ops.hpte_invalidate(slot, vpn, psize,
1814 MMU_PAGE_16M, ssize, local);
1817 tm_flush_hash_page(local);
1819 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1821 void flush_hash_range(unsigned long number, int local)
1823 if (mmu_hash_ops.flush_hash_range)
1824 mmu_hash_ops.flush_hash_range(number, local);
1827 struct ppc64_tlb_batch *batch =
1828 this_cpu_ptr(&ppc64_tlb_batch);
1830 for (i = 0; i < number; i++)
1831 flush_hash_page(batch->vpn[i], batch->pte[i],
1832 batch->psize, batch->ssize, local);
1837 * low_hash_fault is called when we the low level hash code failed
1838 * to instert a PTE due to an hypervisor error
1840 void low_hash_fault(struct pt_regs *regs, unsigned long address, int rc)
1842 enum ctx_state prev_state = exception_enter();
1844 if (user_mode(regs)) {
1845 #ifdef CONFIG_PPC_SUBPAGE_PROT
1847 _exception(SIGSEGV, regs, SEGV_ACCERR, address);
1850 _exception(SIGBUS, regs, BUS_ADRERR, address);
1852 bad_page_fault(regs, address, SIGBUS);
1854 exception_exit(prev_state);
1857 long hpte_insert_repeating(unsigned long hash, unsigned long vpn,
1858 unsigned long pa, unsigned long rflags,
1859 unsigned long vflags, int psize, int ssize)
1861 unsigned long hpte_group;
1865 hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1867 /* Insert into the hash table, primary slot */
1868 slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags, vflags,
1869 psize, psize, ssize);
1871 /* Primary is full, try the secondary */
1872 if (unlikely(slot == -1)) {
1873 hpte_group = (~hash & htab_hash_mask) * HPTES_PER_GROUP;
1874 slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags,
1875 vflags | HPTE_V_SECONDARY,
1876 psize, psize, ssize);
1879 hpte_group = (hash & htab_hash_mask) *
1882 mmu_hash_ops.hpte_remove(hpte_group);
1890 #ifdef CONFIG_DEBUG_PAGEALLOC
1891 static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi)
1894 unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
1895 unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);
1896 unsigned long mode = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL));
1899 hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
1901 /* Don't create HPTE entries for bad address */
1905 ret = hpte_insert_repeating(hash, vpn, __pa(vaddr), mode,
1907 mmu_linear_psize, mmu_kernel_ssize);
1910 spin_lock(&linear_map_hash_lock);
1911 BUG_ON(linear_map_hash_slots[lmi] & 0x80);
1912 linear_map_hash_slots[lmi] = ret | 0x80;
1913 spin_unlock(&linear_map_hash_lock);
1916 static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi)
1918 unsigned long hash, hidx, slot;
1919 unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
1920 unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);
1922 hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
1923 spin_lock(&linear_map_hash_lock);
1924 BUG_ON(!(linear_map_hash_slots[lmi] & 0x80));
1925 hidx = linear_map_hash_slots[lmi] & 0x7f;
1926 linear_map_hash_slots[lmi] = 0;
1927 spin_unlock(&linear_map_hash_lock);
1928 if (hidx & _PTEIDX_SECONDARY)
1930 slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1931 slot += hidx & _PTEIDX_GROUP_IX;
1932 mmu_hash_ops.hpte_invalidate(slot, vpn, mmu_linear_psize,
1934 mmu_kernel_ssize, 0);
1937 void __kernel_map_pages(struct page *page, int numpages, int enable)
1939 unsigned long flags, vaddr, lmi;
1942 local_irq_save(flags);
1943 for (i = 0; i < numpages; i++, page++) {
1944 vaddr = (unsigned long)page_address(page);
1945 lmi = __pa(vaddr) >> PAGE_SHIFT;
1946 if (lmi >= linear_map_hash_count)
1949 kernel_map_linear_page(vaddr, lmi);
1951 kernel_unmap_linear_page(vaddr, lmi);
1953 local_irq_restore(flags);
1955 #endif /* CONFIG_DEBUG_PAGEALLOC */
1957 void hash__setup_initial_memory_limit(phys_addr_t first_memblock_base,
1958 phys_addr_t first_memblock_size)
1961 * We don't currently support the first MEMBLOCK not mapping 0
1962 * physical on those processors
1964 BUG_ON(first_memblock_base != 0);
1967 * On virtualized systems the first entry is our RMA region aka VRMA,
1968 * non-virtualized 64-bit hash MMU systems don't have a limitation
1969 * on real mode access.
1971 * For guests on platforms before POWER9, we clamp the it limit to 1G
1972 * to avoid some funky things such as RTAS bugs etc...
1974 * On POWER9 we limit to 1TB in case the host erroneously told us that
1975 * the RMA was >1TB. Effective address bits 0:23 are treated as zero
1976 * (meaning the access is aliased to zero i.e. addr = addr % 1TB)
1977 * for virtual real mode addressing and so it doesn't make sense to
1978 * have an area larger than 1TB as it can't be addressed.
1980 if (!early_cpu_has_feature(CPU_FTR_HVMODE)) {
1981 ppc64_rma_size = first_memblock_size;
1982 if (!early_cpu_has_feature(CPU_FTR_ARCH_300))
1983 ppc64_rma_size = min_t(u64, ppc64_rma_size, 0x40000000);
1985 ppc64_rma_size = min_t(u64, ppc64_rma_size,
1986 1UL << SID_SHIFT_1T);
1988 /* Finally limit subsequent allocations */
1989 memblock_set_current_limit(ppc64_rma_size);
1991 ppc64_rma_size = ULONG_MAX;
1995 #ifdef CONFIG_DEBUG_FS
1997 static int hpt_order_get(void *data, u64 *val)
1999 *val = ppc64_pft_size;
2003 static int hpt_order_set(void *data, u64 val)
2007 if (!mmu_hash_ops.resize_hpt)
2011 ret = mmu_hash_ops.resize_hpt(val);
2017 DEFINE_DEBUGFS_ATTRIBUTE(fops_hpt_order, hpt_order_get, hpt_order_set, "%llu\n");
2019 static int __init hash64_debugfs(void)
2021 debugfs_create_file("hpt_order", 0600, powerpc_debugfs_root, NULL,
2025 machine_device_initcall(pseries, hash64_debugfs);
2026 #endif /* CONFIG_DEBUG_FS */
2028 void __init print_system_hash_info(void)
2030 pr_info("ppc64_pft_size = 0x%llx\n", ppc64_pft_size);
2033 pr_info("htab_hash_mask = 0x%lx\n", htab_hash_mask);