/* * PowerPC version * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) * * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) * and Cort Dougan (PReP) (cort@cs.nmt.edu) * Copyright (C) 1996 Paul Mackerras * * Derived from "arch/i386/mm/init.c" * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds * * Dave Engebretsen * Rework for PPC64 port. * * 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 #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 #include #include #include #include #include #include #include "mmu_decl.h" #ifdef CONFIG_PPC_STD_MMU_64 #if PGTABLE_RANGE > USER_VSID_RANGE #warning Limited user VSID range means pagetable space is wasted #endif #if (TASK_SIZE_USER64 < PGTABLE_RANGE) && (TASK_SIZE_USER64 < USER_VSID_RANGE) #warning TASK_SIZE is smaller than it needs to be. #endif #endif /* CONFIG_PPC_STD_MMU_64 */ phys_addr_t memstart_addr = ~0; EXPORT_SYMBOL_GPL(memstart_addr); phys_addr_t kernstart_addr; EXPORT_SYMBOL_GPL(kernstart_addr); static void pgd_ctor(void *addr) { memset(addr, 0, PGD_TABLE_SIZE); } static void pmd_ctor(void *addr) { #ifdef CONFIG_TRANSPARENT_HUGEPAGE memset(addr, 0, PMD_TABLE_SIZE * 2); #else memset(addr, 0, PMD_TABLE_SIZE); #endif } struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE]; /* * Create a kmem_cache() for pagetables. This is not used for PTE * pages - they're linked to struct page, come from the normal free * pages pool and have a different entry size (see real_pte_t) to * everything else. Caches created by this function are used for all * the higher level pagetables, and for hugepage pagetables. */ void pgtable_cache_add(unsigned shift, void (*ctor)(void *)) { char *name; unsigned long table_size = sizeof(void *) << shift; unsigned long align = table_size; /* When batching pgtable pointers for RCU freeing, we store * the index size in the low bits. Table alignment must be * big enough to fit it. * * Likewise, hugeapge pagetable pointers contain a (different) * shift value in the low bits. All tables must be aligned so * as to leave enough 0 bits in the address to contain it. */ unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1, HUGEPD_SHIFT_MASK + 1); struct kmem_cache *new; /* It would be nice if this was a BUILD_BUG_ON(), but at the * moment, gcc doesn't seem to recognize is_power_of_2 as a * constant expression, so so much for that. */ BUG_ON(!is_power_of_2(minalign)); BUG_ON((shift < 1) || (shift > MAX_PGTABLE_INDEX_SIZE)); if (PGT_CACHE(shift)) return; /* Already have a cache of this size */ align = max_t(unsigned long, align, minalign); name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift); new = kmem_cache_create(name, table_size, align, 0, ctor); pgtable_cache[shift - 1] = new; pr_debug("Allocated pgtable cache for order %d\n", shift); } void pgtable_cache_init(void) { pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor); pgtable_cache_add(PMD_CACHE_INDEX, pmd_ctor); if (!PGT_CACHE(PGD_INDEX_SIZE) || !PGT_CACHE(PMD_CACHE_INDEX)) panic("Couldn't allocate pgtable caches"); /* In all current configs, when the PUD index exists it's the * same size as either the pgd or pmd index. Verify that the * initialization above has also created a PUD cache. This * will need re-examiniation if we add new possibilities for * the pagetable layout. */ BUG_ON(PUD_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE)); } #ifdef CONFIG_SPARSEMEM_VMEMMAP /* * Given an address within the vmemmap, determine the pfn of the page that * represents the start of the section it is within. Note that we have to * do this by hand as the proffered address may not be correctly aligned. * Subtraction of non-aligned pointers produces undefined results. */ static unsigned long __meminit vmemmap_section_start(unsigned long page) { unsigned long offset = page - ((unsigned long)(vmemmap)); /* Return the pfn of the start of the section. */ return (offset / sizeof(struct page)) & PAGE_SECTION_MASK; } /* * Check if this vmemmap page is already initialised. If any section * which overlaps this vmemmap page is initialised then this page is * initialised already. */ static int __meminit vmemmap_populated(unsigned long start, int page_size) { unsigned long end = start + page_size; start = (unsigned long)(pfn_to_page(vmemmap_section_start(start))); for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page))) if (pfn_valid(page_to_pfn((struct page *)start))) return 1; return 0; } /* On hash-based CPUs, the vmemmap is bolted in the hash table. * * On Book3E CPUs, the vmemmap is currently mapped in the top half of * the vmalloc space using normal page tables, though the size of * pages encoded in the PTEs can be different */ #ifdef CONFIG_PPC_BOOK3E static void __meminit vmemmap_create_mapping(unsigned long start, unsigned long page_size, unsigned long phys) { /* Create a PTE encoding without page size */ unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_KERNEL_RW; /* PTEs only contain page size encodings up to 32M */ BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf); /* Encode the size in the PTE */ flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8; /* For each PTE for that area, map things. Note that we don't * increment phys because all PTEs are of the large size and * thus must have the low bits clear */ for (i = 0; i < page_size; i += PAGE_SIZE) BUG_ON(map_kernel_page(start + i, phys, flags)); } #ifdef CONFIG_MEMORY_HOTPLUG static void vmemmap_remove_mapping(unsigned long start, unsigned long page_size) { } #endif #else /* CONFIG_PPC_BOOK3E */ static void __meminit vmemmap_create_mapping(unsigned long start, unsigned long page_size, unsigned long phys) { int mapped = htab_bolt_mapping(start, start + page_size, phys, pgprot_val(PAGE_KERNEL), mmu_vmemmap_psize, mmu_kernel_ssize); BUG_ON(mapped < 0); } #ifdef CONFIG_MEMORY_HOTPLUG static void vmemmap_remove_mapping(unsigned long start, unsigned long page_size) { int mapped = htab_remove_mapping(start, start + page_size, mmu_vmemmap_psize, mmu_kernel_ssize); BUG_ON(mapped < 0); } #endif #endif /* CONFIG_PPC_BOOK3E */ struct vmemmap_backing *vmemmap_list; static struct vmemmap_backing *next; static int num_left; static int num_freed; static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node) { struct vmemmap_backing *vmem_back; /* get from freed entries first */ if (num_freed) { num_freed--; vmem_back = next; next = next->list; return vmem_back; } /* allocate a page when required and hand out chunks */ if (!num_left) { next = vmemmap_alloc_block(PAGE_SIZE, node); if (unlikely(!next)) { WARN_ON(1); return NULL; } num_left = PAGE_SIZE / sizeof(struct vmemmap_backing); } num_left--; return next++; } static __meminit void vmemmap_list_populate(unsigned long phys, unsigned long start, int node) { struct vmemmap_backing *vmem_back; vmem_back = vmemmap_list_alloc(node); if (unlikely(!vmem_back)) { WARN_ON(1); return; } vmem_back->phys = phys; vmem_back->virt_addr = start; vmem_back->list = vmemmap_list; vmemmap_list = vmem_back; } int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) { unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; /* Align to the page size of the linear mapping. */ start = _ALIGN_DOWN(start, page_size); pr_debug("vmemmap_populate %lx..%lx, node %d\n", start, end, node); for (; start < end; start += page_size) { void *p; if (vmemmap_populated(start, page_size)) continue; p = vmemmap_alloc_block(page_size, node); if (!p) return -ENOMEM; vmemmap_list_populate(__pa(p), start, node); pr_debug(" * %016lx..%016lx allocated at %p\n", start, start + page_size, p); vmemmap_create_mapping(start, page_size, __pa(p)); } return 0; } #ifdef CONFIG_MEMORY_HOTPLUG static unsigned long vmemmap_list_free(unsigned long start) { struct vmemmap_backing *vmem_back, *vmem_back_prev; vmem_back_prev = vmem_back = vmemmap_list; /* look for it with prev pointer recorded */ for (; vmem_back; vmem_back = vmem_back->list) { if (vmem_back->virt_addr == start) break; vmem_back_prev = vmem_back; } if (unlikely(!vmem_back)) { WARN_ON(1); return 0; } /* remove it from vmemmap_list */ if (vmem_back == vmemmap_list) /* remove head */ vmemmap_list = vmem_back->list; else vmem_back_prev->list = vmem_back->list; /* next point to this freed entry */ vmem_back->list = next; next = vmem_back; num_freed++; return vmem_back->phys; } void __ref vmemmap_free(unsigned long start, unsigned long end) { unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; start = _ALIGN_DOWN(start, page_size); pr_debug("vmemmap_free %lx...%lx\n", start, end); for (; start < end; start += page_size) { unsigned long addr; /* * the section has already be marked as invalid, so * vmemmap_populated() true means some other sections still * in this page, so skip it. */ if (vmemmap_populated(start, page_size)) continue; addr = vmemmap_list_free(start); if (addr) { struct page *page = pfn_to_page(addr >> PAGE_SHIFT); if (PageReserved(page)) { /* allocated from bootmem */ if (page_size < PAGE_SIZE) { /* * this shouldn't happen, but if it is * the case, leave the memory there */ WARN_ON_ONCE(1); } else { unsigned int nr_pages = 1 << get_order(page_size); while (nr_pages--) free_reserved_page(page++); } } else free_pages((unsigned long)(__va(addr)), get_order(page_size)); vmemmap_remove_mapping(start, page_size); } } } #endif void register_page_bootmem_memmap(unsigned long section_nr, struct page *start_page, unsigned long size) { } /* * We do not have access to the sparsemem vmemmap, so we fallback to * walking the list of sparsemem blocks which we already maintain for * the sake of crashdump. In the long run, we might want to maintain * a tree if performance of that linear walk becomes a problem. * * realmode_pfn_to_page functions can fail due to: * 1) As real sparsemem blocks do not lay in RAM continously (they * are in virtual address space which is not available in the real mode), * the requested page struct can be split between blocks so get_page/put_page * may fail. * 2) When huge pages are used, the get_page/put_page API will fail * in real mode as the linked addresses in the page struct are virtual * too. */ struct page *realmode_pfn_to_page(unsigned long pfn) { struct vmemmap_backing *vmem_back; struct page *page; unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; unsigned long pg_va = (unsigned long) pfn_to_page(pfn); for (vmem_back = vmemmap_list; vmem_back; vmem_back = vmem_back->list) { if (pg_va < vmem_back->virt_addr) continue; /* After vmemmap_list entry free is possible, need check all */ if ((pg_va + sizeof(struct page)) <= (vmem_back->virt_addr + page_size)) { page = (struct page *) (vmem_back->phys + pg_va - vmem_back->virt_addr); return page; } } /* Probably that page struct is split between real pages */ return NULL; } EXPORT_SYMBOL_GPL(realmode_pfn_to_page); #elif defined(CONFIG_FLATMEM) struct page *realmode_pfn_to_page(unsigned long pfn) { struct page *page = pfn_to_page(pfn); return page; } EXPORT_SYMBOL_GPL(realmode_pfn_to_page); #endif /* CONFIG_SPARSEMEM_VMEMMAP/CONFIG_FLATMEM */