diff options
Diffstat (limited to 'arch/powerpc/mm/init_64.c')
| -rw-r--r-- | arch/powerpc/mm/init_64.c | 526 |
1 files changed, 526 insertions, 0 deletions
diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c new file mode 100644 index 000000000..0ec5b45b1 --- /dev/null +++ b/arch/powerpc/mm/init_64.c @@ -0,0 +1,526 @@ +// 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 <asm/hugetlb.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 traditional 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 freed 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 int 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)) { + pr_debug("vmemap list allocation failed\n"); + return -ENOMEM; + } + + vmem_back->phys = phys; + vmem_back->virt_addr = start; + vmem_back->list = vmemmap_list; + + vmemmap_list = vmem_back; + return 0; +} + +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 - 1) > 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) +{ + bool altmap_alloc; + 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 = vmemmap_alloc_block_buf(page_size, node, altmap); + if (!p) + pr_debug("altmap block allocation failed, falling back to system memory"); + else + altmap_alloc = true; + } + if (!p) { + p = vmemmap_alloc_block_buf(page_size, node, NULL); + altmap_alloc = false; + } + if (!p) + return -ENOMEM; + + if (vmemmap_list_populate(__pa(p), start, node)) { + /* + * If we don't populate vmemap list, we don't have + * the ability to free the allocated vmemmap + * pages in section_deactivate. Hence free them + * here. + */ + int nr_pfns = page_size >> PAGE_SHIFT; + unsigned long page_order = get_order(page_size); + + if (altmap_alloc) + vmem_altmap_free(altmap, nr_pfns); + else + free_pages((unsigned long)p, page_order); + return -ENOMEM; + } + + 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)) + 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; + } + + 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 +unsigned int mmu_lpid_bits; +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE +EXPORT_SYMBOL_GPL(mmu_lpid_bits); +#endif +unsigned int mmu_pid_bits; + +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))) { + cur_cpu_spec->mmu_features &= ~MMU_FTR_GTSE; + } else + cur_cpu_spec->mmu_features |= MMU_FTR_GTSE; + /* 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; + cur_cpu_spec->mmu_features &= ~MMU_FTR_GTSE; + } +} + +static int __init dt_scan_mmu_pid_width(unsigned long node, + const char *uname, int depth, + void *data) +{ + int size = 0; + const __be32 *prop; + const char *type = of_get_flat_dt_prop(node, "device_type", NULL); + + /* We are scanning "cpu" nodes only */ + if (type == NULL || strcmp(type, "cpu") != 0) + return 0; + + /* Find MMU LPID, PID register size */ + prop = of_get_flat_dt_prop(node, "ibm,mmu-lpid-bits", &size); + if (prop && size == 4) + mmu_lpid_bits = be32_to_cpup(prop); + + prop = of_get_flat_dt_prop(node, "ibm,mmu-pid-bits", &size); + if (prop && size == 4) + mmu_pid_bits = be32_to_cpup(prop); + + if (!mmu_pid_bits && !mmu_lpid_bits) + return 0; + + return 1; +} + +void __init mmu_early_init_devtree(void) +{ + bool hvmode = !!(mfmsr() & MSR_HV); + + /* Disable radix mode based on kernel command line. */ + if (disable_radix) { + if (IS_ENABLED(CONFIG_PPC_64S_HASH_MMU)) + cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; + else + pr_warn("WARNING: Ignoring cmdline option disable_radix\n"); + } + + of_scan_flat_dt(dt_scan_mmu_pid_width, NULL); + if (hvmode && !mmu_lpid_bits) { + if (early_cpu_has_feature(CPU_FTR_ARCH_207S)) + mmu_lpid_bits = 12; /* POWER8-10 */ + else + mmu_lpid_bits = 10; /* POWER7 */ + } + if (!mmu_pid_bits) { + if (early_cpu_has_feature(CPU_FTR_ARCH_300)) + mmu_pid_bits = 20; /* POWER9-10 */ + } + + /* + * 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 (!hvmode) + early_check_vec5(); + + if (early_radix_enabled()) { + radix__early_init_devtree(); + + /* + * We have finalized the translation we are going to use by now. + * Radix mode is not limited by RMA / VRMA addressing. + * Hence don't limit memblock allocations. + */ + ppc64_rma_size = ULONG_MAX; + memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE); + } else + hash__early_init_devtree(); + + if (IS_ENABLED(CONFIG_HUGETLB_PAGE_SIZE_VARIABLE)) + hugetlbpage_init_defaultsize(); + + if (!(cur_cpu_spec->mmu_features & MMU_FTR_HPTE_TABLE) && + !(cur_cpu_spec->mmu_features & MMU_FTR_TYPE_RADIX)) + panic("kernel does not support any MMU type offered by platform"); +} +#endif /* CONFIG_PPC_BOOK3S_64 */ |