// SPDX-License-Identifier: GPL-2.0-or-later /* * 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 <engebret@us.ibm.com> * Rework for PPC64 port. */ #undef DEBUG #include <linux/signal.h> #include <linux/sched.h> #include <linux/kernel.h> #include <linux/errno.h> #include <linux/string.h> #include <linux/types.h> #include <linux/mman.h> #include <linux/mm.h> #include <linux/swap.h> #include <linux/stddef.h> #include <linux/vmalloc.h> #include <linux/init.h> #include <linux/delay.h> #include <linux/highmem.h> #include <linux/idr.h> #include <linux/nodemask.h> #include <linux/module.h> #include <linux/poison.h> #include <linux/memblock.h> #include <linux/hugetlb.h> #include <linux/slab.h> #include <linux/of_fdt.h> #include <linux/libfdt.h> #include <linux/memremap.h> #include <asm/pgalloc.h> #include <asm/page.h> #include <asm/prom.h> #include <asm/rtas.h> #include <asm/io.h> #include <asm/mmu_context.h> #include <asm/mmu.h> #include <linux/uaccess.h> #include <asm/smp.h> #include <asm/machdep.h> #include <asm/tlb.h> #include <asm/eeh.h> #include <asm/processor.h> #include <asm/mmzone.h> #include <asm/cputable.h> #include <asm/sections.h> #include <asm/iommu.h> #include <asm/vdso.h> #include <mm/mmu_decl.h> #ifdef CONFIG_SPARSEMEM_VMEMMAP /* * Given an address within the vmemmap, determine the page that * represents the start of the subsection 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 struct page * __meminit vmemmap_subsection_start(unsigned long vmemmap_addr) { unsigned long start_pfn; unsigned long offset = vmemmap_addr - ((unsigned long)(vmemmap)); /* Return the pfn of the start of the section. */ start_pfn = (offset / sizeof(struct page)) & PAGE_SUBSECTION_MASK; return pfn_to_page(start_pfn); } /* * Since memory is added in sub-section chunks, before creating a new vmemmap * mapping, the kernel should check whether there is an existing memmap mapping * covering the new subsection added. This is needed because kernel can map * vmemmap area using 16MB pages which will cover a memory range of 16G. Such * a range covers multiple subsections (2M) * * If any subsection in the 16G range mapped by vmemmap is valid we consider the * vmemmap populated (There is a page table entry already present). We can't do * a page table lookup here because with the hash translation we don't keep * vmemmap details in linux page table. */ static int __meminit vmemmap_populated(unsigned long vmemmap_addr, int vmemmap_map_size) { struct page *start; unsigned long vmemmap_end = vmemmap_addr + vmemmap_map_size; start = vmemmap_subsection_start(vmemmap_addr); for (; (unsigned long)start < vmemmap_end; start += PAGES_PER_SUBSECTION) /* * pfn valid check here is intended to really check * whether we have any subsection already initialized * in this range. */ if (pfn_valid(page_to_pfn(start))) return 1; return 0; } /* * vmemmap virtual address space management does not have a traditonal page * table to track which virtual struct pages are backed by physical mapping. * The virtual to physical mappings are tracked in a simple linked list * format. 'vmemmap_list' maintains the entire vmemmap physical mapping at * all times where as the 'next' list maintains the available * vmemmap_backing structures which have been deleted from the * 'vmemmap_global' list during system runtime (memory hotplug remove * operation). The freed 'vmemmap_backing' structures are reused later when * new requests come in without allocating fresh memory. This pointer also * tracks the allocated 'vmemmap_backing' structures as we allocate one * full page memory at a time when we dont have any. */ struct vmemmap_backing *vmemmap_list; static struct vmemmap_backing *next; /* * The same pointer 'next' tracks individual chunks inside the allocated * full page during the boot time and again tracks the freeed nodes during * runtime. It is racy but it does not happen as they are separated by the * boot process. Will create problem if some how we have memory hotplug * operation during boot !! */ 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; } static bool altmap_cross_boundary(struct vmem_altmap *altmap, unsigned long start, unsigned long page_size) { unsigned long nr_pfn = page_size / sizeof(struct page); unsigned long start_pfn = page_to_pfn((struct page *)start); if ((start_pfn + nr_pfn) > altmap->end_pfn) return true; if (start_pfn < altmap->base_pfn) return true; return false; } int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, struct vmem_altmap *altmap) { 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 = NULL; int rc; /* * This vmemmap range is backing different subsections. If any * of that subsection is marked valid, that means we already * have initialized a page table covering this range and hence * the vmemmap range is populated. */ if (vmemmap_populated(start, page_size)) continue; /* * Allocate from the altmap first if we have one. This may * fail due to alignment issues when using 16MB hugepages, so * fall back to system memory if the altmap allocation fail. */ if (altmap && !altmap_cross_boundary(altmap, start, page_size)) { p = altmap_alloc_block_buf(page_size, altmap); if (!p) pr_debug("altmap block allocation failed, falling back to system memory"); } if (!p) p = vmemmap_alloc_block_buf(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); rc = vmemmap_create_mapping(start, page_size, __pa(p)); if (rc < 0) { pr_warn("%s: Unable to create vmemmap mapping: %d\n", __func__, rc); return -EFAULT; } } 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, struct vmem_altmap *altmap) { unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; unsigned long page_order = get_order(page_size); unsigned long alt_start = ~0, alt_end = ~0; unsigned long base_pfn; start = ALIGN_DOWN(start, page_size); if (altmap) { alt_start = altmap->base_pfn; alt_end = altmap->base_pfn + altmap->reserve + altmap->free + altmap->alloc + altmap->align; } pr_debug("vmemmap_free %lx...%lx\n", start, end); for (; start < end; start += page_size) { unsigned long nr_pages, addr; struct page *page; /* * We have already marked the subsection we are trying to remove * invalid. So if we want to remove the vmemmap range, we * need to make sure there is no subsection marked valid * in this range. */ if (vmemmap_populated(start, page_size)) continue; addr = vmemmap_list_free(start); if (!addr) continue; page = pfn_to_page(addr >> PAGE_SHIFT); nr_pages = 1 << page_order; base_pfn = PHYS_PFN(addr); if (base_pfn >= alt_start && base_pfn < alt_end) { vmem_altmap_free(altmap, nr_pages); } else 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 { while (nr_pages--) free_reserved_page(page++); } } else { free_pages((unsigned long)(__va(addr)), page_order); } vmemmap_remove_mapping(start, page_size); } } #endif void register_page_bootmem_memmap(unsigned long section_nr, struct page *start_page, unsigned long size) { } #endif /* CONFIG_SPARSEMEM_VMEMMAP */ #ifdef CONFIG_PPC_BOOK3S_64 static bool disable_radix = !IS_ENABLED(CONFIG_PPC_RADIX_MMU_DEFAULT); static int __init parse_disable_radix(char *p) { bool val; if (!p) val = true; else if (kstrtobool(p, &val)) return -EINVAL; disable_radix = val; return 0; } early_param("disable_radix", parse_disable_radix); /* * If we're running under a hypervisor, we need to check the contents of * /chosen/ibm,architecture-vec-5 to see if the hypervisor is willing to do * radix. If not, we clear the radix feature bit so we fall back to hash. */ static void __init early_check_vec5(void) { unsigned long root, chosen; int size; const u8 *vec5; u8 mmu_supported; root = of_get_flat_dt_root(); chosen = of_get_flat_dt_subnode_by_name(root, "chosen"); if (chosen == -FDT_ERR_NOTFOUND) { cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; return; } vec5 = of_get_flat_dt_prop(chosen, "ibm,architecture-vec-5", &size); if (!vec5) { cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; return; } if (size <= OV5_INDX(OV5_MMU_SUPPORT)) { cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; return; } /* Check for supported configuration */ mmu_supported = vec5[OV5_INDX(OV5_MMU_SUPPORT)] & OV5_FEAT(OV5_MMU_SUPPORT); if (mmu_supported == OV5_FEAT(OV5_MMU_RADIX)) { /* Hypervisor only supports radix - check enabled && GTSE */ if (!early_radix_enabled()) { pr_warn("WARNING: Ignoring cmdline option disable_radix\n"); } if (!(vec5[OV5_INDX(OV5_RADIX_GTSE)] & OV5_FEAT(OV5_RADIX_GTSE))) { pr_warn("WARNING: Hypervisor doesn't support RADIX with GTSE\n"); } /* Do radix anyway - the hypervisor said we had to */ cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX; } else if (mmu_supported == OV5_FEAT(OV5_MMU_HASH)) { /* Hypervisor only supports hash - disable radix */ cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; } } void __init mmu_early_init_devtree(void) { /* Disable radix mode based on kernel command line. */ if (disable_radix) cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; /* * Check /chosen/ibm,architecture-vec-5 if running as a guest. * When running bare-metal, we can use radix if we like * even though the ibm,architecture-vec-5 property created by * skiboot doesn't have the necessary bits set. */ if (!(mfmsr() & MSR_HV)) early_check_vec5(); if (early_radix_enabled()) radix__early_init_devtree(); else hash__early_init_devtree(); } #endif /* CONFIG_PPC_BOOK3S_64 */