/* * PowerPC64 port by Mike Corrigan and Dave Engebretsen * {mikejc|engebret}@us.ibm.com * * Copyright (c) 2000 Mike Corrigan * * SMP scalability work: * Copyright (C) 2001 Anton Blanchard , IBM * * Module name: htab.c * * Description: * PowerPC Hashed Page Table functions * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #undef DEBUG #undef DEBUG_LOW #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DEBUG #define DBG(fmt...) udbg_printf(fmt) #else #define DBG(fmt...) #endif #ifdef DEBUG_LOW #define DBG_LOW(fmt...) udbg_printf(fmt) #else #define DBG_LOW(fmt...) #endif #define KB (1024) #define MB (1024*KB) #define GB (1024L*MB) /* * Note: pte --> Linux PTE * HPTE --> PowerPC Hashed Page Table Entry * * Execution context: * htab_initialize is called with the MMU off (of course), but * the kernel has been copied down to zero so it can directly * reference global data. At this point it is very difficult * to print debug info. * */ #ifdef CONFIG_U3_DART extern unsigned long dart_tablebase; #endif /* CONFIG_U3_DART */ static unsigned long _SDR1; struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT]; struct hash_pte *htab_address; unsigned long htab_size_bytes; unsigned long htab_hash_mask; EXPORT_SYMBOL_GPL(htab_hash_mask); int mmu_linear_psize = MMU_PAGE_4K; int mmu_virtual_psize = MMU_PAGE_4K; int mmu_vmalloc_psize = MMU_PAGE_4K; #ifdef CONFIG_SPARSEMEM_VMEMMAP int mmu_vmemmap_psize = MMU_PAGE_4K; #endif int mmu_io_psize = MMU_PAGE_4K; int mmu_kernel_ssize = MMU_SEGSIZE_256M; int mmu_highuser_ssize = MMU_SEGSIZE_256M; u16 mmu_slb_size = 64; EXPORT_SYMBOL_GPL(mmu_slb_size); #ifdef CONFIG_PPC_64K_PAGES int mmu_ci_restrictions; #endif #ifdef CONFIG_DEBUG_PAGEALLOC static u8 *linear_map_hash_slots; static unsigned long linear_map_hash_count; static DEFINE_SPINLOCK(linear_map_hash_lock); #endif /* CONFIG_DEBUG_PAGEALLOC */ /* There are definitions of page sizes arrays to be used when none * is provided by the firmware. */ /* Pre-POWER4 CPUs (4k pages only) */ static struct mmu_psize_def mmu_psize_defaults_old[] = { [MMU_PAGE_4K] = { .shift = 12, .sllp = 0, .penc = 0, .avpnm = 0, .tlbiel = 0, }, }; /* POWER4, GPUL, POWER5 * * Support for 16Mb large pages */ static struct mmu_psize_def mmu_psize_defaults_gp[] = { [MMU_PAGE_4K] = { .shift = 12, .sllp = 0, .penc = 0, .avpnm = 0, .tlbiel = 1, }, [MMU_PAGE_16M] = { .shift = 24, .sllp = SLB_VSID_L, .penc = 0, .avpnm = 0x1UL, .tlbiel = 0, }, }; static unsigned long htab_convert_pte_flags(unsigned long pteflags) { unsigned long rflags = pteflags & 0x1fa; /* _PAGE_EXEC -> NOEXEC */ if ((pteflags & _PAGE_EXEC) == 0) rflags |= HPTE_R_N; /* PP bits. PAGE_USER is already PP bit 0x2, so we only * need to add in 0x1 if it's a read-only user page */ if ((pteflags & _PAGE_USER) && !((pteflags & _PAGE_RW) && (pteflags & _PAGE_DIRTY))) rflags |= 1; /* Always add C */ return rflags | HPTE_R_C; } int htab_bolt_mapping(unsigned long vstart, unsigned long vend, unsigned long pstart, unsigned long prot, int psize, int ssize) { unsigned long vaddr, paddr; unsigned int step, shift; int ret = 0; shift = mmu_psize_defs[psize].shift; step = 1 << shift; prot = htab_convert_pte_flags(prot); DBG("htab_bolt_mapping(%lx..%lx -> %lx (%lx,%d,%d)\n", vstart, vend, pstart, prot, psize, ssize); for (vaddr = vstart, paddr = pstart; vaddr < vend; vaddr += step, paddr += step) { unsigned long hash, hpteg; unsigned long vsid = get_kernel_vsid(vaddr, ssize); unsigned long va = hpt_va(vaddr, vsid, ssize); unsigned long tprot = prot; /* Make kernel text executable */ if (overlaps_kernel_text(vaddr, vaddr + step)) tprot &= ~HPTE_R_N; hash = hpt_hash(va, shift, ssize); hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP); BUG_ON(!ppc_md.hpte_insert); ret = ppc_md.hpte_insert(hpteg, va, paddr, tprot, HPTE_V_BOLTED, psize, ssize); if (ret < 0) break; #ifdef CONFIG_DEBUG_PAGEALLOC if ((paddr >> PAGE_SHIFT) < linear_map_hash_count) linear_map_hash_slots[paddr >> PAGE_SHIFT] = ret | 0x80; #endif /* CONFIG_DEBUG_PAGEALLOC */ } return ret < 0 ? ret : 0; } #ifdef CONFIG_MEMORY_HOTPLUG static int htab_remove_mapping(unsigned long vstart, unsigned long vend, int psize, int ssize) { unsigned long vaddr; unsigned int step, shift; shift = mmu_psize_defs[psize].shift; step = 1 << shift; if (!ppc_md.hpte_removebolted) { printk(KERN_WARNING "Platform doesn't implement " "hpte_removebolted\n"); return -EINVAL; } for (vaddr = vstart; vaddr < vend; vaddr += step) ppc_md.hpte_removebolted(vaddr, psize, ssize); return 0; } #endif /* CONFIG_MEMORY_HOTPLUG */ static int __init htab_dt_scan_seg_sizes(unsigned long node, const char *uname, int depth, void *data) { char *type = of_get_flat_dt_prop(node, "device_type", NULL); u32 *prop; unsigned long size = 0; /* We are scanning "cpu" nodes only */ if (type == NULL || strcmp(type, "cpu") != 0) return 0; prop = (u32 *)of_get_flat_dt_prop(node, "ibm,processor-segment-sizes", &size); if (prop == NULL) return 0; for (; size >= 4; size -= 4, ++prop) { if (prop[0] == 40) { DBG("1T segment support detected\n"); cur_cpu_spec->mmu_features |= MMU_FTR_1T_SEGMENT; return 1; } } cur_cpu_spec->mmu_features &= ~MMU_FTR_NO_SLBIE_B; return 0; } static void __init htab_init_seg_sizes(void) { of_scan_flat_dt(htab_dt_scan_seg_sizes, NULL); } static int __init htab_dt_scan_page_sizes(unsigned long node, const char *uname, int depth, void *data) { char *type = of_get_flat_dt_prop(node, "device_type", NULL); u32 *prop; unsigned long size = 0; /* We are scanning "cpu" nodes only */ if (type == NULL || strcmp(type, "cpu") != 0) return 0; prop = (u32 *)of_get_flat_dt_prop(node, "ibm,segment-page-sizes", &size); if (prop != NULL) { DBG("Page sizes from device-tree:\n"); size /= 4; cur_cpu_spec->mmu_features &= ~(MMU_FTR_16M_PAGE); while(size > 0) { unsigned int shift = prop[0]; unsigned int slbenc = prop[1]; unsigned int lpnum = prop[2]; unsigned int lpenc = 0; struct mmu_psize_def *def; int idx = -1; size -= 3; prop += 3; while(size > 0 && lpnum) { if (prop[0] == shift) lpenc = prop[1]; prop += 2; size -= 2; lpnum--; } switch(shift) { case 0xc: idx = MMU_PAGE_4K; break; case 0x10: idx = MMU_PAGE_64K; break; case 0x14: idx = MMU_PAGE_1M; break; case 0x18: idx = MMU_PAGE_16M; cur_cpu_spec->mmu_features |= MMU_FTR_16M_PAGE; break; case 0x22: idx = MMU_PAGE_16G; break; } if (idx < 0) continue; def = &mmu_psize_defs[idx]; def->shift = shift; if (shift <= 23) def->avpnm = 0; else def->avpnm = (1 << (shift - 23)) - 1; def->sllp = slbenc; def->penc = lpenc; /* We don't know for sure what's up with tlbiel, so * for now we only set it for 4K and 64K pages */ if (idx == MMU_PAGE_4K || idx == MMU_PAGE_64K) def->tlbiel = 1; else def->tlbiel = 0; DBG(" %d: shift=%02x, sllp=%04lx, avpnm=%08lx, " "tlbiel=%d, penc=%d\n", idx, shift, def->sllp, def->avpnm, def->tlbiel, def->penc); } return 1; } return 0; } #ifdef CONFIG_HUGETLB_PAGE /* Scan for 16G memory blocks that have been set aside for huge pages * and reserve those blocks for 16G huge pages. */ static int __init htab_dt_scan_hugepage_blocks(unsigned long node, const char *uname, int depth, void *data) { char *type = of_get_flat_dt_prop(node, "device_type", NULL); unsigned long *addr_prop; u32 *page_count_prop; unsigned int expected_pages; long unsigned int phys_addr; long unsigned int block_size; /* We are scanning "memory" nodes only */ if (type == NULL || strcmp(type, "memory") != 0) return 0; /* This property is the log base 2 of the number of virtual pages that * will represent this memory block. */ page_count_prop = of_get_flat_dt_prop(node, "ibm,expected#pages", NULL); if (page_count_prop == NULL) return 0; expected_pages = (1 << page_count_prop[0]); addr_prop = of_get_flat_dt_prop(node, "reg", NULL); if (addr_prop == NULL) return 0; phys_addr = addr_prop[0]; block_size = addr_prop[1]; if (block_size != (16 * GB)) return 0; printk(KERN_INFO "Huge page(16GB) memory: " "addr = 0x%lX size = 0x%lX pages = %d\n", phys_addr, block_size, expected_pages); if (phys_addr + (16 * GB) <= memblock_end_of_DRAM()) { memblock_reserve(phys_addr, block_size * expected_pages); add_gpage(phys_addr, block_size, expected_pages); } return 0; } #endif /* CONFIG_HUGETLB_PAGE */ static void __init htab_init_page_sizes(void) { int rc; /* Default to 4K pages only */ memcpy(mmu_psize_defs, mmu_psize_defaults_old, sizeof(mmu_psize_defaults_old)); /* * Try to find the available page sizes in the device-tree */ rc = of_scan_flat_dt(htab_dt_scan_page_sizes, NULL); if (rc != 0) /* Found */ goto found; /* * Not in the device-tree, let's fallback on known size * list for 16M capable GP & GR */ if (mmu_has_feature(MMU_FTR_16M_PAGE)) memcpy(mmu_psize_defs, mmu_psize_defaults_gp, sizeof(mmu_psize_defaults_gp)); found: #ifndef CONFIG_DEBUG_PAGEALLOC /* * Pick a size for the linear mapping. Currently, we only support * 16M, 1M and 4K which is the default */ if (mmu_psize_defs[MMU_PAGE_16M].shift) mmu_linear_psize = MMU_PAGE_16M; else if (mmu_psize_defs[MMU_PAGE_1M].shift) mmu_linear_psize = MMU_PAGE_1M; #endif /* CONFIG_DEBUG_PAGEALLOC */ #ifdef CONFIG_PPC_64K_PAGES /* * Pick a size for the ordinary pages. Default is 4K, we support * 64K for user mappings and vmalloc if supported by the processor. * We only use 64k for ioremap if the processor * (and firmware) support cache-inhibited large pages. * If not, we use 4k and set mmu_ci_restrictions so that * hash_page knows to switch processes that use cache-inhibited * mappings to 4k pages. */ if (mmu_psize_defs[MMU_PAGE_64K].shift) { mmu_virtual_psize = MMU_PAGE_64K; mmu_vmalloc_psize = MMU_PAGE_64K; if (mmu_linear_psize == MMU_PAGE_4K) mmu_linear_psize = MMU_PAGE_64K; if (mmu_has_feature(MMU_FTR_CI_LARGE_PAGE)) { /* * Don't use 64k pages for ioremap on pSeries, since * that would stop us accessing the HEA ethernet. */ if (!machine_is(pseries)) mmu_io_psize = MMU_PAGE_64K; } else mmu_ci_restrictions = 1; } #endif /* CONFIG_PPC_64K_PAGES */ #ifdef CONFIG_SPARSEMEM_VMEMMAP /* We try to use 16M pages for vmemmap if that is supported * and we have at least 1G of RAM at boot */ if (mmu_psize_defs[MMU_PAGE_16M].shift && memblock_phys_mem_size() >= 0x40000000) mmu_vmemmap_psize = MMU_PAGE_16M; else if (mmu_psize_defs[MMU_PAGE_64K].shift) mmu_vmemmap_psize = MMU_PAGE_64K; else mmu_vmemmap_psize = MMU_PAGE_4K; #endif /* CONFIG_SPARSEMEM_VMEMMAP */ printk(KERN_DEBUG "Page orders: linear mapping = %d, " "virtual = %d, io = %d" #ifdef CONFIG_SPARSEMEM_VMEMMAP ", vmemmap = %d" #endif "\n", mmu_psize_defs[mmu_linear_psize].shift, mmu_psize_defs[mmu_virtual_psize].shift, mmu_psize_defs[mmu_io_psize].shift #ifdef CONFIG_SPARSEMEM_VMEMMAP ,mmu_psize_defs[mmu_vmemmap_psize].shift #endif ); #ifdef CONFIG_HUGETLB_PAGE /* Reserve 16G huge page memory sections for huge pages */ of_scan_flat_dt(htab_dt_scan_hugepage_blocks, NULL); #endif /* CONFIG_HUGETLB_PAGE */ } static int __init htab_dt_scan_pftsize(unsigned long node, const char *uname, int depth, void *data) { char *type = of_get_flat_dt_prop(node, "device_type", NULL); u32 *prop; /* We are scanning "cpu" nodes only */ if (type == NULL || strcmp(type, "cpu") != 0) return 0; prop = (u32 *)of_get_flat_dt_prop(node, "ibm,pft-size", NULL); if (prop != NULL) { /* pft_size[0] is the NUMA CEC cookie */ ppc64_pft_size = prop[1]; return 1; } return 0; } static unsigned long __init htab_get_table_size(void) { unsigned long mem_size, rnd_mem_size, pteg_count, psize; /* If hash size isn't already provided by the platform, we try to * retrieve it from the device-tree. If it's not there neither, we * calculate it now based on the total RAM size */ if (ppc64_pft_size == 0) of_scan_flat_dt(htab_dt_scan_pftsize, NULL); if (ppc64_pft_size) return 1UL << ppc64_pft_size; /* round mem_size up to next power of 2 */ mem_size = memblock_phys_mem_size(); rnd_mem_size = 1UL << __ilog2(mem_size); if (rnd_mem_size < mem_size) rnd_mem_size <<= 1; /* # pages / 2 */ psize = mmu_psize_defs[mmu_virtual_psize].shift; pteg_count = max(rnd_mem_size >> (psize + 1), 1UL << 11); return pteg_count << 7; } #ifdef CONFIG_MEMORY_HOTPLUG int create_section_mapping(unsigned long start, unsigned long end) { return htab_bolt_mapping(start, end, __pa(start), pgprot_val(PAGE_KERNEL), mmu_linear_psize, mmu_kernel_ssize); } int remove_section_mapping(unsigned long start, unsigned long end) { return htab_remove_mapping(start, end, mmu_linear_psize, mmu_kernel_ssize); } #endif /* CONFIG_MEMORY_HOTPLUG */ #define FUNCTION_TEXT(A) ((*(unsigned long *)(A))) static void __init htab_finish_init(void) { extern unsigned int *htab_call_hpte_insert1; extern unsigned int *htab_call_hpte_insert2; extern unsigned int *htab_call_hpte_remove; extern unsigned int *htab_call_hpte_updatepp; #ifdef CONFIG_PPC_HAS_HASH_64K extern unsigned int *ht64_call_hpte_insert1; extern unsigned int *ht64_call_hpte_insert2; extern unsigned int *ht64_call_hpte_remove; extern unsigned int *ht64_call_hpte_updatepp; patch_branch(ht64_call_hpte_insert1, FUNCTION_TEXT(ppc_md.hpte_insert), BRANCH_SET_LINK); patch_branch(ht64_call_hpte_insert2, FUNCTION_TEXT(ppc_md.hpte_insert), BRANCH_SET_LINK); patch_branch(ht64_call_hpte_remove, FUNCTION_TEXT(ppc_md.hpte_remove), BRANCH_SET_LINK); patch_branch(ht64_call_hpte_updatepp, FUNCTION_TEXT(ppc_md.hpte_updatepp), BRANCH_SET_LINK); #endif /* CONFIG_PPC_HAS_HASH_64K */ patch_branch(htab_call_hpte_insert1, FUNCTION_TEXT(ppc_md.hpte_insert), BRANCH_SET_LINK); patch_branch(htab_call_hpte_insert2, FUNCTION_TEXT(ppc_md.hpte_insert), BRANCH_SET_LINK); patch_branch(htab_call_hpte_remove, FUNCTION_TEXT(ppc_md.hpte_remove), BRANCH_SET_LINK); patch_branch(htab_call_hpte_updatepp, FUNCTION_TEXT(ppc_md.hpte_updatepp), BRANCH_SET_LINK); } static void __init htab_initialize(void) { unsigned long table; unsigned long pteg_count; unsigned long prot; unsigned long base = 0, size = 0, limit; struct memblock_region *reg; DBG(" -> htab_initialize()\n"); /* Initialize segment sizes */ htab_init_seg_sizes(); /* Initialize page sizes */ htab_init_page_sizes(); if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) { mmu_kernel_ssize = MMU_SEGSIZE_1T; mmu_highuser_ssize = MMU_SEGSIZE_1T; printk(KERN_INFO "Using 1TB segments\n"); } /* * Calculate the required size of the htab. We want the number of * PTEGs to equal one half the number of real pages. */ htab_size_bytes = htab_get_table_size(); pteg_count = htab_size_bytes >> 7; htab_hash_mask = pteg_count - 1; if (firmware_has_feature(FW_FEATURE_LPAR)) { /* Using a hypervisor which owns the htab */ htab_address = NULL; _SDR1 = 0; #ifdef CONFIG_FA_DUMP /* * If firmware assisted dump is active firmware preserves * the contents of htab along with entire partition memory. * Clear the htab if firmware assisted dump is active so * that we dont end up using old mappings. */ if (is_fadump_active() && ppc_md.hpte_clear_all) ppc_md.hpte_clear_all(); #endif } else { /* Find storage for the HPT. Must be contiguous in * the absolute address space. On cell we want it to be * in the first 2 Gig so we can use it for IOMMU hacks. */ if (machine_is(cell)) limit = 0x80000000; else limit = MEMBLOCK_ALLOC_ANYWHERE; table = memblock_alloc_base(htab_size_bytes, htab_size_bytes, limit); DBG("Hash table allocated at %lx, size: %lx\n", table, htab_size_bytes); htab_address = abs_to_virt(table); /* htab absolute addr + encoded htabsize */ _SDR1 = table + __ilog2(pteg_count) - 11; /* Initialize the HPT with no entries */ memset((void *)table, 0, htab_size_bytes); /* Set SDR1 */ mtspr(SPRN_SDR1, _SDR1); } prot = pgprot_val(PAGE_KERNEL); #ifdef CONFIG_DEBUG_PAGEALLOC linear_map_hash_count = memblock_end_of_DRAM() >> PAGE_SHIFT; linear_map_hash_slots = __va(memblock_alloc_base(linear_map_hash_count, 1, ppc64_rma_size)); memset(linear_map_hash_slots, 0, linear_map_hash_count); #endif /* CONFIG_DEBUG_PAGEALLOC */ /* On U3 based machines, we need to reserve the DART area and * _NOT_ map it to avoid cache paradoxes as it's remapped non * cacheable later on */ /* create bolted the linear mapping in the hash table */ for_each_memblock(memory, reg) { base = (unsigned long)__va(reg->base); size = reg->size; DBG("creating mapping for region: %lx..%lx (prot: %lx)\n", base, size, prot); #ifdef CONFIG_U3_DART /* Do not map the DART space. Fortunately, it will be aligned * in such a way that it will not cross two memblock regions and * will fit within a single 16Mb page. * The DART space is assumed to be a full 16Mb region even if * we only use 2Mb of that space. We will use more of it later * for AGP GART. We have to use a full 16Mb large page. */ DBG("DART base: %lx\n", dart_tablebase); if (dart_tablebase != 0 && dart_tablebase >= base && dart_tablebase < (base + size)) { unsigned long dart_table_end = dart_tablebase + 16 * MB; if (base != dart_tablebase) BUG_ON(htab_bolt_mapping(base, dart_tablebase, __pa(base), prot, mmu_linear_psize, mmu_kernel_ssize)); if ((base + size) > dart_table_end) BUG_ON(htab_bolt_mapping(dart_tablebase+16*MB, base + size, __pa(dart_table_end), prot, mmu_linear_psize, mmu_kernel_ssize)); continue; } #endif /* CONFIG_U3_DART */ BUG_ON(htab_bolt_mapping(base, base + size, __pa(base), prot, mmu_linear_psize, mmu_kernel_ssize)); } memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE); /* * If we have a memory_limit and we've allocated TCEs then we need to * explicitly map the TCE area at the top of RAM. We also cope with the * case that the TCEs start below memory_limit. * tce_alloc_start/end are 16MB aligned so the mapping should work * for either 4K or 16MB pages. */ if (tce_alloc_start) { tce_alloc_start = (unsigned long)__va(tce_alloc_start); tce_alloc_end = (unsigned long)__va(tce_alloc_end); if (base + size >= tce_alloc_start) tce_alloc_start = base + size + 1; BUG_ON(htab_bolt_mapping(tce_alloc_start, tce_alloc_end, __pa(tce_alloc_start), prot, mmu_linear_psize, mmu_kernel_ssize)); } htab_finish_init(); DBG(" <- htab_initialize()\n"); } #undef KB #undef MB void __init early_init_mmu(void) { /* Setup initial STAB address in the PACA */ get_paca()->stab_real = __pa((u64)&initial_stab); get_paca()->stab_addr = (u64)&initial_stab; /* Initialize the MMU Hash table and create the linear mapping * of memory. Has to be done before stab/slb initialization as * this is currently where the page size encoding is obtained */ htab_initialize(); /* Initialize stab / SLB management */ if (mmu_has_feature(MMU_FTR_SLB)) slb_initialize(); else stab_initialize(get_paca()->stab_real); } #ifdef CONFIG_SMP void __cpuinit early_init_mmu_secondary(void) { /* Initialize hash table for that CPU */ if (!firmware_has_feature(FW_FEATURE_LPAR)) mtspr(SPRN_SDR1, _SDR1); /* Initialize STAB/SLB. We use a virtual address as it works * in real mode on pSeries. */ if (mmu_has_feature(MMU_FTR_SLB)) slb_initialize(); else stab_initialize(get_paca()->stab_addr); } #endif /* CONFIG_SMP */ /* * Called by asm hashtable.S for doing lazy icache flush */ unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap) { struct page *page; if (!pfn_valid(pte_pfn(pte))) return pp; page = pte_page(pte); /* page is dirty */ if (!test_bit(PG_arch_1, &page->flags) && !PageReserved(page)) { if (trap == 0x400) { flush_dcache_icache_page(page); set_bit(PG_arch_1, &page->flags); } else pp |= HPTE_R_N; } return pp; } #ifdef CONFIG_PPC_MM_SLICES unsigned int get_paca_psize(unsigned long addr) { unsigned long index, slices; if (addr < SLICE_LOW_TOP) { slices = get_paca()->context.low_slices_psize; index = GET_LOW_SLICE_INDEX(addr); } else { slices = get_paca()->context.high_slices_psize; index = GET_HIGH_SLICE_INDEX(addr); } return (slices >> (index * 4)) & 0xF; } #else unsigned int get_paca_psize(unsigned long addr) { return get_paca()->context.user_psize; } #endif /* * Demote a segment to using 4k pages. * For now this makes the whole process use 4k pages. */ #ifdef CONFIG_PPC_64K_PAGES void demote_segment_4k(struct mm_struct *mm, unsigned long addr) { if (get_slice_psize(mm, addr) == MMU_PAGE_4K) return; slice_set_range_psize(mm, addr, 1, MMU_PAGE_4K); #ifdef CONFIG_SPU_BASE spu_flush_all_slbs(mm); #endif if (get_paca_psize(addr) != MMU_PAGE_4K) { get_paca()->context = mm->context; slb_flush_and_rebolt(); } } #endif /* CONFIG_PPC_64K_PAGES */ #ifdef CONFIG_PPC_SUBPAGE_PROT /* * This looks up a 2-bit protection code for a 4k subpage of a 64k page. * Userspace sets the subpage permissions using the subpage_prot system call. * * Result is 0: full permissions, _PAGE_RW: read-only, * _PAGE_USER or _PAGE_USER|_PAGE_RW: no access. */ static int subpage_protection(struct mm_struct *mm, unsigned long ea) { struct subpage_prot_table *spt = &mm->context.spt; u32 spp = 0; u32 **sbpm, *sbpp; if (ea >= spt->maxaddr) return 0; if (ea < 0x100000000) { /* addresses below 4GB use spt->low_prot */ sbpm = spt->low_prot; } else { sbpm = spt->protptrs[ea >> SBP_L3_SHIFT]; if (!sbpm) return 0; } sbpp = sbpm[(ea >> SBP_L2_SHIFT) & (SBP_L2_COUNT - 1)]; if (!sbpp) return 0; spp = sbpp[(ea >> PAGE_SHIFT) & (SBP_L1_COUNT - 1)]; /* extract 2-bit bitfield for this 4k subpage */ spp >>= 30 - 2 * ((ea >> 12) & 0xf); /* turn 0,1,2,3 into combination of _PAGE_USER and _PAGE_RW */ spp = ((spp & 2) ? _PAGE_USER : 0) | ((spp & 1) ? _PAGE_RW : 0); return spp; } #else /* CONFIG_PPC_SUBPAGE_PROT */ static inline int subpage_protection(struct mm_struct *mm, unsigned long ea) { return 0; } #endif void hash_failure_debug(unsigned long ea, unsigned long access, unsigned long vsid, unsigned long trap, int ssize, int psize, unsigned long pte) { if (!printk_ratelimit()) return; pr_info("mm: Hashing failure ! EA=0x%lx access=0x%lx current=%s\n", ea, access, current->comm); pr_info(" trap=0x%lx vsid=0x%lx ssize=%d psize=%d pte=0x%lx\n", trap, vsid, ssize, psize, pte); } /* Result code is: * 0 - handled * 1 - normal page fault * -1 - critical hash insertion error * -2 - access not permitted by subpage protection mechanism */ int hash_page(unsigned long ea, unsigned long access, unsigned long trap) { pgd_t *pgdir; unsigned long vsid; struct mm_struct *mm; pte_t *ptep; unsigned hugeshift; const struct cpumask *tmp; int rc, user_region = 0, local = 0; int psize, ssize; DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n", ea, access, trap); if ((ea & ~REGION_MASK) >= PGTABLE_RANGE) { DBG_LOW(" out of pgtable range !\n"); return 1; } /* Get region & vsid */ switch (REGION_ID(ea)) { case USER_REGION_ID: user_region = 1; mm = current->mm; if (! mm) { DBG_LOW(" user region with no mm !\n"); return 1; } psize = get_slice_psize(mm, ea); ssize = user_segment_size(ea); vsid = get_vsid(mm->context.id, ea, ssize); break; case VMALLOC_REGION_ID: mm = &init_mm; vsid = get_kernel_vsid(ea, mmu_kernel_ssize); if (ea < VMALLOC_END) psize = mmu_vmalloc_psize; else psize = mmu_io_psize; ssize = mmu_kernel_ssize; break; default: /* Not a valid range * Send the problem up to do_page_fault */ return 1; } DBG_LOW(" mm=%p, mm->pgdir=%p, vsid=%016lx\n", mm, mm->pgd, vsid); /* Get pgdir */ pgdir = mm->pgd; if (pgdir == NULL) return 1; /* Check CPU locality */ tmp = cpumask_of(smp_processor_id()); if (user_region && cpumask_equal(mm_cpumask(mm), tmp)) local = 1; #ifndef CONFIG_PPC_64K_PAGES /* If we use 4K pages and our psize is not 4K, then we might * be hitting a special driver mapping, and need to align the * address before we fetch the PTE. * * It could also be a hugepage mapping, in which case this is * not necessary, but it's not harmful, either. */ if (psize != MMU_PAGE_4K) ea &= ~((1ul << mmu_psize_defs[psize].shift) - 1); #endif /* CONFIG_PPC_64K_PAGES */ /* Get PTE and page size from page tables */ ptep = find_linux_pte_or_hugepte(pgdir, ea, &hugeshift); if (ptep == NULL || !pte_present(*ptep)) { DBG_LOW(" no PTE !\n"); return 1; } /* Add _PAGE_PRESENT to the required access perm */ access |= _PAGE_PRESENT; /* Pre-check access permissions (will be re-checked atomically * in __hash_page_XX but this pre-check is a fast path */ if (access & ~pte_val(*ptep)) { DBG_LOW(" no access !\n"); return 1; } #ifdef CONFIG_HUGETLB_PAGE if (hugeshift) return __hash_page_huge(ea, access, vsid, ptep, trap, local, ssize, hugeshift, psize); #endif /* CONFIG_HUGETLB_PAGE */ #ifndef CONFIG_PPC_64K_PAGES DBG_LOW(" i-pte: %016lx\n", pte_val(*ptep)); #else DBG_LOW(" i-pte: %016lx %016lx\n", pte_val(*ptep), pte_val(*(ptep + PTRS_PER_PTE))); #endif /* Do actual hashing */ #ifdef CONFIG_PPC_64K_PAGES /* If _PAGE_4K_PFN is set, make sure this is a 4k segment */ if ((pte_val(*ptep) & _PAGE_4K_PFN) && psize == MMU_PAGE_64K) { demote_segment_4k(mm, ea); psize = MMU_PAGE_4K; } /* If this PTE is non-cacheable and we have restrictions on * using non cacheable large pages, then we switch to 4k */ if (mmu_ci_restrictions && psize == MMU_PAGE_64K && (pte_val(*ptep) & _PAGE_NO_CACHE)) { if (user_region) { demote_segment_4k(mm, ea); psize = MMU_PAGE_4K; } else if (ea < VMALLOC_END) { /* * some driver did a non-cacheable mapping * in vmalloc space, so switch vmalloc * to 4k pages */ printk(KERN_ALERT "Reducing vmalloc segment " "to 4kB pages because of " "non-cacheable mapping\n"); psize = mmu_vmalloc_psize = MMU_PAGE_4K; #ifdef CONFIG_SPU_BASE spu_flush_all_slbs(mm); #endif } } if (user_region) { if (psize != get_paca_psize(ea)) { get_paca()->context = mm->context; slb_flush_and_rebolt(); } } else if (get_paca()->vmalloc_sllp != mmu_psize_defs[mmu_vmalloc_psize].sllp) { get_paca()->vmalloc_sllp = mmu_psize_defs[mmu_vmalloc_psize].sllp; slb_vmalloc_update(); } #endif /* CONFIG_PPC_64K_PAGES */ #ifdef CONFIG_PPC_HAS_HASH_64K if (psize == MMU_PAGE_64K) rc = __hash_page_64K(ea, access, vsid, ptep, trap, local, ssize); else #endif /* CONFIG_PPC_HAS_HASH_64K */ { int spp = subpage_protection(mm, ea); if (access & spp) rc = -2; else rc = __hash_page_4K(ea, access, vsid, ptep, trap, local, ssize, spp); } /* Dump some info in case of hash insertion failure, they should * never happen so it is really useful to know if/when they do */ if (rc == -1) hash_failure_debug(ea, access, vsid, trap, ssize, psize, pte_val(*ptep)); #ifndef CONFIG_PPC_64K_PAGES DBG_LOW(" o-pte: %016lx\n", pte_val(*ptep)); #else DBG_LOW(" o-pte: %016lx %016lx\n", pte_val(*ptep), pte_val(*(ptep + PTRS_PER_PTE))); #endif DBG_LOW(" -> rc=%d\n", rc); return rc; } EXPORT_SYMBOL_GPL(hash_page); void hash_preload(struct mm_struct *mm, unsigned long ea, unsigned long access, unsigned long trap) { unsigned long vsid; pgd_t *pgdir; pte_t *ptep; unsigned long flags; int rc, ssize, local = 0; BUG_ON(REGION_ID(ea) != USER_REGION_ID); #ifdef CONFIG_PPC_MM_SLICES /* We only prefault standard pages for now */ if (unlikely(get_slice_psize(mm, ea) != mm->context.user_psize)) return; #endif DBG_LOW("hash_preload(mm=%p, mm->pgdir=%p, ea=%016lx, access=%lx," " trap=%lx\n", mm, mm->pgd, ea, access, trap); /* Get Linux PTE if available */ pgdir = mm->pgd; if (pgdir == NULL) return; ptep = find_linux_pte(pgdir, ea); if (!ptep) return; #ifdef CONFIG_PPC_64K_PAGES /* If either _PAGE_4K_PFN or _PAGE_NO_CACHE is set (and we are on * a 64K kernel), then we don't preload, hash_page() will take * care of it once we actually try to access the page. * That way we don't have to duplicate all of the logic for segment * page size demotion here */ if (pte_val(*ptep) & (_PAGE_4K_PFN | _PAGE_NO_CACHE)) return; #endif /* CONFIG_PPC_64K_PAGES */ /* Get VSID */ ssize = user_segment_size(ea); vsid = get_vsid(mm->context.id, ea, ssize); /* Hash doesn't like irqs */ local_irq_save(flags); /* Is that local to this CPU ? */ if (cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id()))) local = 1; /* Hash it in */ #ifdef CONFIG_PPC_HAS_HASH_64K if (mm->context.user_psize == MMU_PAGE_64K) rc = __hash_page_64K(ea, access, vsid, ptep, trap, local, ssize); else #endif /* CONFIG_PPC_HAS_HASH_64K */ rc = __hash_page_4K(ea, access, vsid, ptep, trap, local, ssize, subpage_protection(mm, ea)); /* Dump some info in case of hash insertion failure, they should * never happen so it is really useful to know if/when they do */ if (rc == -1) hash_failure_debug(ea, access, vsid, trap, ssize, mm->context.user_psize, pte_val(*ptep)); local_irq_restore(flags); } /* WARNING: This is called from hash_low_64.S, if you change this prototype, * do not forget to update the assembly call site ! */ void flush_hash_page(unsigned long va, real_pte_t pte, int psize, int ssize, int local) { unsigned long hash, index, shift, hidx, slot; DBG_LOW("flush_hash_page(va=%016lx)\n", va); pte_iterate_hashed_subpages(pte, psize, va, index, shift) { hash = hpt_hash(va, shift, ssize); hidx = __rpte_to_hidx(pte, index); if (hidx & _PTEIDX_SECONDARY) hash = ~hash; slot = (hash & htab_hash_mask) * HPTES_PER_GROUP; slot += hidx & _PTEIDX_GROUP_IX; DBG_LOW(" sub %ld: hash=%lx, hidx=%lx\n", index, slot, hidx); ppc_md.hpte_invalidate(slot, va, psize, ssize, local); } pte_iterate_hashed_end(); } void flush_hash_range(unsigned long number, int local) { if (ppc_md.flush_hash_range) ppc_md.flush_hash_range(number, local); else { int i; struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch); for (i = 0; i < number; i++) flush_hash_page(batch->vaddr[i], batch->pte[i], batch->psize, batch->ssize, local); } } /* * low_hash_fault is called when we the low level hash code failed * to instert a PTE due to an hypervisor error */ void low_hash_fault(struct pt_regs *regs, unsigned long address, int rc) { if (user_mode(regs)) { #ifdef CONFIG_PPC_SUBPAGE_PROT if (rc == -2) _exception(SIGSEGV, regs, SEGV_ACCERR, address); else #endif _exception(SIGBUS, regs, BUS_ADRERR, address); } else bad_page_fault(regs, address, SIGBUS); } #ifdef CONFIG_DEBUG_PAGEALLOC static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi) { unsigned long hash, hpteg; unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize); unsigned long va = hpt_va(vaddr, vsid, mmu_kernel_ssize); unsigned long mode = htab_convert_pte_flags(PAGE_KERNEL); int ret; hash = hpt_hash(va, PAGE_SHIFT, mmu_kernel_ssize); hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP); ret = ppc_md.hpte_insert(hpteg, va, __pa(vaddr), mode, HPTE_V_BOLTED, mmu_linear_psize, mmu_kernel_ssize); BUG_ON (ret < 0); spin_lock(&linear_map_hash_lock); BUG_ON(linear_map_hash_slots[lmi] & 0x80); linear_map_hash_slots[lmi] = ret | 0x80; spin_unlock(&linear_map_hash_lock); } static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi) { unsigned long hash, hidx, slot; unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize); unsigned long va = hpt_va(vaddr, vsid, mmu_kernel_ssize); hash = hpt_hash(va, PAGE_SHIFT, mmu_kernel_ssize); spin_lock(&linear_map_hash_lock); BUG_ON(!(linear_map_hash_slots[lmi] & 0x80)); hidx = linear_map_hash_slots[lmi] & 0x7f; linear_map_hash_slots[lmi] = 0; spin_unlock(&linear_map_hash_lock); if (hidx & _PTEIDX_SECONDARY) hash = ~hash; slot = (hash & htab_hash_mask) * HPTES_PER_GROUP; slot += hidx & _PTEIDX_GROUP_IX; ppc_md.hpte_invalidate(slot, va, mmu_linear_psize, mmu_kernel_ssize, 0); } void kernel_map_pages(struct page *page, int numpages, int enable) { unsigned long flags, vaddr, lmi; int i; local_irq_save(flags); for (i = 0; i < numpages; i++, page++) { vaddr = (unsigned long)page_address(page); lmi = __pa(vaddr) >> PAGE_SHIFT; if (lmi >= linear_map_hash_count) continue; if (enable) kernel_map_linear_page(vaddr, lmi); else kernel_unmap_linear_page(vaddr, lmi); } local_irq_restore(flags); } #endif /* CONFIG_DEBUG_PAGEALLOC */ void setup_initial_memory_limit(phys_addr_t first_memblock_base, phys_addr_t first_memblock_size) { /* We don't currently support the first MEMBLOCK not mapping 0 * physical on those processors */ BUG_ON(first_memblock_base != 0); /* On LPAR systems, the first entry is our RMA region, * non-LPAR 64-bit hash MMU systems don't have a limitation * on real mode access, but using the first entry works well * enough. We also clamp it to 1G to avoid some funky things * such as RTAS bugs etc... */ ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000); /* Finally limit subsequent allocations */ memblock_set_current_limit(ppc64_rma_size); }