v4.19.13 snapshot.
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
new file mode 100644
index 0000000..04ccb27
--- /dev/null
+++ b/arch/powerpc/mm/mem.c
@@ -0,0 +1,599 @@
+/*
+ * 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
+ * PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
+ *
+ * Derived from "arch/i386/mm/init.c"
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ *
+ * 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.
+ *
+ */
+
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/gfp.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/stddef.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/highmem.h>
+#include <linux/initrd.h>
+#include <linux/pagemap.h>
+#include <linux/suspend.h>
+#include <linux/memblock.h>
+#include <linux/hugetlb.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/memremap.h>
+
+#include <asm/pgalloc.h>
+#include <asm/prom.h>
+#include <asm/io.h>
+#include <asm/mmu_context.h>
+#include <asm/pgtable.h>
+#include <asm/mmu.h>
+#include <asm/smp.h>
+#include <asm/machdep.h>
+#include <asm/btext.h>
+#include <asm/tlb.h>
+#include <asm/sections.h>
+#include <asm/sparsemem.h>
+#include <asm/vdso.h>
+#include <asm/fixmap.h>
+#include <asm/swiotlb.h>
+#include <asm/rtas.h>
+
+#include "mmu_decl.h"
+
+#ifndef CPU_FTR_COHERENT_ICACHE
+#define CPU_FTR_COHERENT_ICACHE 0 /* XXX for now */
+#define CPU_FTR_NOEXECUTE 0
+#endif
+
+unsigned long long memory_limit;
+bool init_mem_is_free;
+
+#ifdef CONFIG_HIGHMEM
+pte_t *kmap_pte;
+EXPORT_SYMBOL(kmap_pte);
+pgprot_t kmap_prot;
+EXPORT_SYMBOL(kmap_prot);
+#define TOP_ZONE ZONE_HIGHMEM
+
+static inline pte_t *virt_to_kpte(unsigned long vaddr)
+{
+ return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
+ vaddr), vaddr), vaddr);
+}
+#else
+#define TOP_ZONE ZONE_NORMAL
+#endif
+
+int page_is_ram(unsigned long pfn)
+{
+ return memblock_is_memory(__pfn_to_phys(pfn));
+}
+
+pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+ unsigned long size, pgprot_t vma_prot)
+{
+ if (ppc_md.phys_mem_access_prot)
+ return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
+
+ if (!page_is_ram(pfn))
+ vma_prot = pgprot_noncached(vma_prot);
+
+ return vma_prot;
+}
+EXPORT_SYMBOL(phys_mem_access_prot);
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+
+#ifdef CONFIG_NUMA
+int memory_add_physaddr_to_nid(u64 start)
+{
+ return hot_add_scn_to_nid(start);
+}
+#endif
+
+int __weak create_section_mapping(unsigned long start, unsigned long end, int nid)
+{
+ return -ENODEV;
+}
+
+int __weak remove_section_mapping(unsigned long start, unsigned long end)
+{
+ return -ENODEV;
+}
+
+int __meminit arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
+ bool want_memblock)
+{
+ unsigned long start_pfn = start >> PAGE_SHIFT;
+ unsigned long nr_pages = size >> PAGE_SHIFT;
+ int rc;
+
+ resize_hpt_for_hotplug(memblock_phys_mem_size());
+
+ start = (unsigned long)__va(start);
+ rc = create_section_mapping(start, start + size, nid);
+ if (rc) {
+ pr_warn("Unable to create mapping for hot added memory 0x%llx..0x%llx: %d\n",
+ start, start + size, rc);
+ return -EFAULT;
+ }
+ flush_inval_dcache_range(start, start + size);
+
+ return __add_pages(nid, start_pfn, nr_pages, altmap, want_memblock);
+}
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+int __meminit arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
+{
+ unsigned long start_pfn = start >> PAGE_SHIFT;
+ unsigned long nr_pages = size >> PAGE_SHIFT;
+ struct page *page;
+ int ret;
+
+ /*
+ * If we have an altmap then we need to skip over any reserved PFNs
+ * when querying the zone.
+ */
+ page = pfn_to_page(start_pfn);
+ if (altmap)
+ page += vmem_altmap_offset(altmap);
+
+ ret = __remove_pages(page_zone(page), start_pfn, nr_pages, altmap);
+ if (ret)
+ return ret;
+
+ /* Remove htab bolted mappings for this section of memory */
+ start = (unsigned long)__va(start);
+ flush_inval_dcache_range(start, start + size);
+ ret = remove_section_mapping(start, start + size);
+
+ /* Ensure all vmalloc mappings are flushed in case they also
+ * hit that section of memory
+ */
+ vm_unmap_aliases();
+
+ resize_hpt_for_hotplug(memblock_phys_mem_size());
+
+ return ret;
+}
+#endif
+#endif /* CONFIG_MEMORY_HOTPLUG */
+
+/*
+ * walk_memory_resource() needs to make sure there is no holes in a given
+ * memory range. PPC64 does not maintain the memory layout in /proc/iomem.
+ * Instead it maintains it in memblock.memory structures. Walk through the
+ * memory regions, find holes and callback for contiguous regions.
+ */
+int
+walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
+ void *arg, int (*func)(unsigned long, unsigned long, void *))
+{
+ struct memblock_region *reg;
+ unsigned long end_pfn = start_pfn + nr_pages;
+ unsigned long tstart, tend;
+ int ret = -1;
+
+ for_each_memblock(memory, reg) {
+ tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
+ tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
+ if (tstart >= tend)
+ continue;
+ ret = (*func)(tstart, tend - tstart, arg);
+ if (ret)
+ break;
+ }
+ return ret;
+}
+EXPORT_SYMBOL_GPL(walk_system_ram_range);
+
+#ifndef CONFIG_NEED_MULTIPLE_NODES
+void __init mem_topology_setup(void)
+{
+ max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
+ min_low_pfn = MEMORY_START >> PAGE_SHIFT;
+#ifdef CONFIG_HIGHMEM
+ max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
+#endif
+
+ /* Place all memblock_regions in the same node and merge contiguous
+ * memblock_regions
+ */
+ memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
+}
+
+void __init initmem_init(void)
+{
+ /* XXX need to clip this if using highmem? */
+ sparse_memory_present_with_active_regions(0);
+ sparse_init();
+}
+
+/* mark pages that don't exist as nosave */
+static int __init mark_nonram_nosave(void)
+{
+ struct memblock_region *reg, *prev = NULL;
+
+ for_each_memblock(memory, reg) {
+ if (prev &&
+ memblock_region_memory_end_pfn(prev) < memblock_region_memory_base_pfn(reg))
+ register_nosave_region(memblock_region_memory_end_pfn(prev),
+ memblock_region_memory_base_pfn(reg));
+ prev = reg;
+ }
+ return 0;
+}
+#else /* CONFIG_NEED_MULTIPLE_NODES */
+static int __init mark_nonram_nosave(void)
+{
+ return 0;
+}
+#endif
+
+static bool zone_limits_final;
+
+/*
+ * The memory zones past TOP_ZONE are managed by generic mm code.
+ * These should be set to zero since that's what every other
+ * architecture does.
+ */
+static unsigned long max_zone_pfns[MAX_NR_ZONES] = {
+ [0 ... TOP_ZONE ] = ~0UL,
+ [TOP_ZONE + 1 ... MAX_NR_ZONES - 1] = 0
+};
+
+/*
+ * Restrict the specified zone and all more restrictive zones
+ * to be below the specified pfn. May not be called after
+ * paging_init().
+ */
+void __init limit_zone_pfn(enum zone_type zone, unsigned long pfn_limit)
+{
+ int i;
+
+ if (WARN_ON(zone_limits_final))
+ return;
+
+ for (i = zone; i >= 0; i--) {
+ if (max_zone_pfns[i] > pfn_limit)
+ max_zone_pfns[i] = pfn_limit;
+ }
+}
+
+/*
+ * Find the least restrictive zone that is entirely below the
+ * specified pfn limit. Returns < 0 if no suitable zone is found.
+ *
+ * pfn_limit must be u64 because it can exceed 32 bits even on 32-bit
+ * systems -- the DMA limit can be higher than any possible real pfn.
+ */
+int dma_pfn_limit_to_zone(u64 pfn_limit)
+{
+ int i;
+
+ for (i = TOP_ZONE; i >= 0; i--) {
+ if (max_zone_pfns[i] <= pfn_limit)
+ return i;
+ }
+
+ return -EPERM;
+}
+
+/*
+ * paging_init() sets up the page tables - in fact we've already done this.
+ */
+void __init paging_init(void)
+{
+ unsigned long long total_ram = memblock_phys_mem_size();
+ phys_addr_t top_of_ram = memblock_end_of_DRAM();
+
+#ifdef CONFIG_PPC32
+ unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
+ unsigned long end = __fix_to_virt(FIX_HOLE);
+
+ for (; v < end; v += PAGE_SIZE)
+ map_kernel_page(v, 0, 0); /* XXX gross */
+#endif
+
+#ifdef CONFIG_HIGHMEM
+ map_kernel_page(PKMAP_BASE, 0, 0); /* XXX gross */
+ pkmap_page_table = virt_to_kpte(PKMAP_BASE);
+
+ kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
+ kmap_prot = PAGE_KERNEL;
+#endif /* CONFIG_HIGHMEM */
+
+ printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
+ (unsigned long long)top_of_ram, total_ram);
+ printk(KERN_DEBUG "Memory hole size: %ldMB\n",
+ (long int)((top_of_ram - total_ram) >> 20));
+
+#ifdef CONFIG_HIGHMEM
+ limit_zone_pfn(ZONE_NORMAL, lowmem_end_addr >> PAGE_SHIFT);
+#endif
+ limit_zone_pfn(TOP_ZONE, top_of_ram >> PAGE_SHIFT);
+ zone_limits_final = true;
+ free_area_init_nodes(max_zone_pfns);
+
+ mark_nonram_nosave();
+}
+
+void __init mem_init(void)
+{
+ /*
+ * book3s is limited to 16 page sizes due to encoding this in
+ * a 4-bit field for slices.
+ */
+ BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
+
+#ifdef CONFIG_SWIOTLB
+ swiotlb_init(0);
+#endif
+
+ high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
+ set_max_mapnr(max_pfn);
+ free_all_bootmem();
+
+#ifdef CONFIG_HIGHMEM
+ {
+ unsigned long pfn, highmem_mapnr;
+
+ highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
+ for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
+ phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
+ struct page *page = pfn_to_page(pfn);
+ if (!memblock_is_reserved(paddr))
+ free_highmem_page(page);
+ }
+ }
+#endif /* CONFIG_HIGHMEM */
+
+#if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP)
+ /*
+ * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
+ * functions.... do it here for the non-smp case.
+ */
+ per_cpu(next_tlbcam_idx, smp_processor_id()) =
+ (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
+#endif
+
+ mem_init_print_info(NULL);
+#ifdef CONFIG_PPC32
+ pr_info("Kernel virtual memory layout:\n");
+ pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP);
+#ifdef CONFIG_HIGHMEM
+ pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n",
+ PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
+#endif /* CONFIG_HIGHMEM */
+#ifdef CONFIG_NOT_COHERENT_CACHE
+ pr_info(" * 0x%08lx..0x%08lx : consistent mem\n",
+ IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE);
+#endif /* CONFIG_NOT_COHERENT_CACHE */
+ pr_info(" * 0x%08lx..0x%08lx : early ioremap\n",
+ ioremap_bot, IOREMAP_TOP);
+ pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n",
+ VMALLOC_START, VMALLOC_END);
+#endif /* CONFIG_PPC32 */
+}
+
+void free_initmem(void)
+{
+ ppc_md.progress = ppc_printk_progress;
+ mark_initmem_nx();
+ init_mem_is_free = true;
+ free_initmem_default(POISON_FREE_INITMEM);
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void __init free_initrd_mem(unsigned long start, unsigned long end)
+{
+ free_reserved_area((void *)start, (void *)end, -1, "initrd");
+}
+#endif
+
+/*
+ * This is called when a page has been modified by the kernel.
+ * It just marks the page as not i-cache clean. We do the i-cache
+ * flush later when the page is given to a user process, if necessary.
+ */
+void flush_dcache_page(struct page *page)
+{
+ if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
+ return;
+ /* avoid an atomic op if possible */
+ if (test_bit(PG_arch_1, &page->flags))
+ clear_bit(PG_arch_1, &page->flags);
+}
+EXPORT_SYMBOL(flush_dcache_page);
+
+void flush_dcache_icache_page(struct page *page)
+{
+#ifdef CONFIG_HUGETLB_PAGE
+ if (PageCompound(page)) {
+ flush_dcache_icache_hugepage(page);
+ return;
+ }
+#endif
+#if defined(CONFIG_PPC_8xx) || defined(CONFIG_PPC64)
+ /* On 8xx there is no need to kmap since highmem is not supported */
+ __flush_dcache_icache(page_address(page));
+#else
+ if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) {
+ void *start = kmap_atomic(page);
+ __flush_dcache_icache(start);
+ kunmap_atomic(start);
+ } else {
+ __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
+ }
+#endif
+}
+EXPORT_SYMBOL(flush_dcache_icache_page);
+
+void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
+{
+ clear_page(page);
+
+ /*
+ * We shouldn't have to do this, but some versions of glibc
+ * require it (ld.so assumes zero filled pages are icache clean)
+ * - Anton
+ */
+ flush_dcache_page(pg);
+}
+EXPORT_SYMBOL(clear_user_page);
+
+void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
+ struct page *pg)
+{
+ copy_page(vto, vfrom);
+
+ /*
+ * We should be able to use the following optimisation, however
+ * there are two problems.
+ * Firstly a bug in some versions of binutils meant PLT sections
+ * were not marked executable.
+ * Secondly the first word in the GOT section is blrl, used
+ * to establish the GOT address. Until recently the GOT was
+ * not marked executable.
+ * - Anton
+ */
+#if 0
+ if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
+ return;
+#endif
+
+ flush_dcache_page(pg);
+}
+
+void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
+ unsigned long addr, int len)
+{
+ unsigned long maddr;
+
+ maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
+ flush_icache_range(maddr, maddr + len);
+ kunmap(page);
+}
+EXPORT_SYMBOL(flush_icache_user_range);
+
+/*
+ * This is called at the end of handling a user page fault, when the
+ * fault has been handled by updating a PTE in the linux page tables.
+ * We use it to preload an HPTE into the hash table corresponding to
+ * the updated linux PTE.
+ *
+ * This must always be called with the pte lock held.
+ */
+void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
+ pte_t *ptep)
+{
+#ifdef CONFIG_PPC_STD_MMU
+ /*
+ * We don't need to worry about _PAGE_PRESENT here because we are
+ * called with either mm->page_table_lock held or ptl lock held
+ */
+ unsigned long access, trap;
+
+ if (radix_enabled()) {
+ prefetch((void *)address);
+ return;
+ }
+
+ /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
+ if (!pte_young(*ptep) || address >= TASK_SIZE)
+ return;
+
+ /* We try to figure out if we are coming from an instruction
+ * access fault and pass that down to __hash_page so we avoid
+ * double-faulting on execution of fresh text. We have to test
+ * for regs NULL since init will get here first thing at boot
+ *
+ * We also avoid filling the hash if not coming from a fault
+ */
+
+ trap = current->thread.regs ? TRAP(current->thread.regs) : 0UL;
+ switch (trap) {
+ case 0x300:
+ access = 0UL;
+ break;
+ case 0x400:
+ access = _PAGE_EXEC;
+ break;
+ default:
+ return;
+ }
+
+ hash_preload(vma->vm_mm, address, access, trap);
+#endif /* CONFIG_PPC_STD_MMU */
+#if (defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_FSL_BOOK3E)) \
+ && defined(CONFIG_HUGETLB_PAGE)
+ if (is_vm_hugetlb_page(vma))
+ book3e_hugetlb_preload(vma, address, *ptep);
+#endif
+}
+
+/*
+ * System memory should not be in /proc/iomem but various tools expect it
+ * (eg kdump).
+ */
+static int __init add_system_ram_resources(void)
+{
+ struct memblock_region *reg;
+
+ for_each_memblock(memory, reg) {
+ struct resource *res;
+ unsigned long base = reg->base;
+ unsigned long size = reg->size;
+
+ res = kzalloc(sizeof(struct resource), GFP_KERNEL);
+ WARN_ON(!res);
+
+ if (res) {
+ res->name = "System RAM";
+ res->start = base;
+ res->end = base + size - 1;
+ res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+ WARN_ON(request_resource(&iomem_resource, res) < 0);
+ }
+ }
+
+ return 0;
+}
+subsys_initcall(add_system_ram_resources);
+
+#ifdef CONFIG_STRICT_DEVMEM
+/*
+ * devmem_is_allowed(): check to see if /dev/mem access to a certain address
+ * is valid. The argument is a physical page number.
+ *
+ * Access has to be given to non-kernel-ram areas as well, these contain the
+ * PCI mmio resources as well as potential bios/acpi data regions.
+ */
+int devmem_is_allowed(unsigned long pfn)
+{
+ if (page_is_rtas_user_buf(pfn))
+ return 1;
+ if (iomem_is_exclusive(PFN_PHYS(pfn)))
+ return 0;
+ if (!page_is_ram(pfn))
+ return 1;
+ return 0;
+}
+#endif /* CONFIG_STRICT_DEVMEM */