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- // SPDX-License-Identifier: GPL-2.0-or-later
- /*
- * PowerPC version
- * Copyright (C) 1995-1996 Gary Thomas ([email protected])
- *
- * Modifications by Paul Mackerras (PowerMac) ([email protected])
- * and Cort Dougan (PReP) ([email protected])
- * Copyright (C) 1996 Paul Mackerras
- *
- * Derived from "arch/i386/mm/init.c"
- * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
- *
- * Dave Engebretsen <[email protected]>
- * 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 */
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