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![David Gibson](/assets/img/avatar_default.png)
We've now implemented code in the pseries platform to use the new PAPR interface to allow resizing the hash page table (HPT) at runtime. This patch uses that interface to automatically attempt to resize the HPT when memory is hot added or removed. This tries to always keep the HPT at a reasonable size for our current memory size. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
599 lines
15 KiB
C
599 lines
15 KiB
C
/*
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* PowerPC version
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* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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*
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* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
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* and Cort Dougan (PReP) (cort@cs.nmt.edu)
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* Copyright (C) 1996 Paul Mackerras
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* PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
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*
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* Derived from "arch/i386/mm/init.c"
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* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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*/
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#include <linux/export.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/gfp.h>
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#include <linux/types.h>
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#include <linux/mm.h>
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#include <linux/stddef.h>
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#include <linux/init.h>
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#include <linux/bootmem.h>
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#include <linux/highmem.h>
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#include <linux/initrd.h>
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#include <linux/pagemap.h>
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#include <linux/suspend.h>
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#include <linux/memblock.h>
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#include <linux/hugetlb.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <asm/pgalloc.h>
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#include <asm/prom.h>
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#include <asm/io.h>
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#include <asm/mmu_context.h>
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#include <asm/pgtable.h>
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#include <asm/mmu.h>
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#include <asm/smp.h>
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#include <asm/machdep.h>
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#include <asm/btext.h>
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#include <asm/tlb.h>
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#include <asm/sections.h>
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#include <asm/sparsemem.h>
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#include <asm/vdso.h>
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#include <asm/fixmap.h>
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#include <asm/swiotlb.h>
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#include <asm/rtas.h>
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#include "mmu_decl.h"
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#ifndef CPU_FTR_COHERENT_ICACHE
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#define CPU_FTR_COHERENT_ICACHE 0 /* XXX for now */
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#define CPU_FTR_NOEXECUTE 0
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#endif
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unsigned long long memory_limit;
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#ifdef CONFIG_HIGHMEM
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pte_t *kmap_pte;
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EXPORT_SYMBOL(kmap_pte);
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pgprot_t kmap_prot;
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EXPORT_SYMBOL(kmap_prot);
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#define TOP_ZONE ZONE_HIGHMEM
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static inline pte_t *virt_to_kpte(unsigned long vaddr)
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{
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return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
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vaddr), vaddr), vaddr);
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}
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#else
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#define TOP_ZONE ZONE_NORMAL
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#endif
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int page_is_ram(unsigned long pfn)
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{
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#ifndef CONFIG_PPC64 /* XXX for now */
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return pfn < max_pfn;
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#else
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unsigned long paddr = (pfn << PAGE_SHIFT);
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struct memblock_region *reg;
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for_each_memblock(memory, reg)
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if (paddr >= reg->base && paddr < (reg->base + reg->size))
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return 1;
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return 0;
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#endif
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}
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pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
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unsigned long size, pgprot_t vma_prot)
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{
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if (ppc_md.phys_mem_access_prot)
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return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
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if (!page_is_ram(pfn))
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vma_prot = pgprot_noncached(vma_prot);
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return vma_prot;
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}
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EXPORT_SYMBOL(phys_mem_access_prot);
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#ifdef CONFIG_MEMORY_HOTPLUG
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#ifdef CONFIG_NUMA
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int memory_add_physaddr_to_nid(u64 start)
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{
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return hot_add_scn_to_nid(start);
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}
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#endif
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int __weak create_section_mapping(unsigned long start, unsigned long end)
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{
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return -ENODEV;
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}
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int __weak remove_section_mapping(unsigned long start, unsigned long end)
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{
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return -ENODEV;
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}
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int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
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{
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struct pglist_data *pgdata;
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struct zone *zone;
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unsigned long start_pfn = start >> PAGE_SHIFT;
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unsigned long nr_pages = size >> PAGE_SHIFT;
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int rc;
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resize_hpt_for_hotplug(memblock_phys_mem_size());
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pgdata = NODE_DATA(nid);
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start = (unsigned long)__va(start);
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rc = create_section_mapping(start, start + size);
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if (rc) {
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pr_warning(
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"Unable to create mapping for hot added memory 0x%llx..0x%llx: %d\n",
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start, start + size, rc);
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return -EFAULT;
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}
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/* this should work for most non-highmem platforms */
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zone = pgdata->node_zones +
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zone_for_memory(nid, start, size, 0, for_device);
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return __add_pages(nid, zone, start_pfn, nr_pages);
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}
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#ifdef CONFIG_MEMORY_HOTREMOVE
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int arch_remove_memory(u64 start, u64 size)
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{
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unsigned long start_pfn = start >> PAGE_SHIFT;
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unsigned long nr_pages = size >> PAGE_SHIFT;
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struct zone *zone;
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int ret;
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zone = page_zone(pfn_to_page(start_pfn));
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ret = __remove_pages(zone, start_pfn, nr_pages);
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if (ret)
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return ret;
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/* Remove htab bolted mappings for this section of memory */
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start = (unsigned long)__va(start);
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ret = remove_section_mapping(start, start + size);
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/* Ensure all vmalloc mappings are flushed in case they also
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* hit that section of memory
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*/
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vm_unmap_aliases();
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resize_hpt_for_hotplug(memblock_phys_mem_size());
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return ret;
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}
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#endif
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#endif /* CONFIG_MEMORY_HOTPLUG */
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/*
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* walk_memory_resource() needs to make sure there is no holes in a given
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* memory range. PPC64 does not maintain the memory layout in /proc/iomem.
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* Instead it maintains it in memblock.memory structures. Walk through the
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* memory regions, find holes and callback for contiguous regions.
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*/
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int
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walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
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void *arg, int (*func)(unsigned long, unsigned long, void *))
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{
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struct memblock_region *reg;
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unsigned long end_pfn = start_pfn + nr_pages;
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unsigned long tstart, tend;
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int ret = -1;
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for_each_memblock(memory, reg) {
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tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
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tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
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if (tstart >= tend)
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continue;
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ret = (*func)(tstart, tend - tstart, arg);
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if (ret)
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break;
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}
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return ret;
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}
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EXPORT_SYMBOL_GPL(walk_system_ram_range);
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#ifndef CONFIG_NEED_MULTIPLE_NODES
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void __init initmem_init(void)
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{
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max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
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min_low_pfn = MEMORY_START >> PAGE_SHIFT;
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#ifdef CONFIG_HIGHMEM
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max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
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#endif
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/* Place all memblock_regions in the same node and merge contiguous
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* memblock_regions
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*/
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memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0);
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/* XXX need to clip this if using highmem? */
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sparse_memory_present_with_active_regions(0);
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sparse_init();
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}
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/* mark pages that don't exist as nosave */
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static int __init mark_nonram_nosave(void)
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{
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struct memblock_region *reg, *prev = NULL;
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for_each_memblock(memory, reg) {
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if (prev &&
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memblock_region_memory_end_pfn(prev) < memblock_region_memory_base_pfn(reg))
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register_nosave_region(memblock_region_memory_end_pfn(prev),
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memblock_region_memory_base_pfn(reg));
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prev = reg;
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}
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return 0;
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}
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#else /* CONFIG_NEED_MULTIPLE_NODES */
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static int __init mark_nonram_nosave(void)
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{
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return 0;
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}
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#endif
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static bool zone_limits_final;
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/*
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* The memory zones past TOP_ZONE are managed by generic mm code.
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* These should be set to zero since that's what every other
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* architecture does.
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*/
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static unsigned long max_zone_pfns[MAX_NR_ZONES] = {
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[0 ... TOP_ZONE ] = ~0UL,
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[TOP_ZONE + 1 ... MAX_NR_ZONES - 1] = 0
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};
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/*
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* Restrict the specified zone and all more restrictive zones
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* to be below the specified pfn. May not be called after
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* paging_init().
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*/
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void __init limit_zone_pfn(enum zone_type zone, unsigned long pfn_limit)
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{
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int i;
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if (WARN_ON(zone_limits_final))
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return;
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for (i = zone; i >= 0; i--) {
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if (max_zone_pfns[i] > pfn_limit)
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max_zone_pfns[i] = pfn_limit;
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}
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}
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/*
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* Find the least restrictive zone that is entirely below the
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* specified pfn limit. Returns < 0 if no suitable zone is found.
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*
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* pfn_limit must be u64 because it can exceed 32 bits even on 32-bit
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* systems -- the DMA limit can be higher than any possible real pfn.
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*/
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int dma_pfn_limit_to_zone(u64 pfn_limit)
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{
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int i;
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for (i = TOP_ZONE; i >= 0; i--) {
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if (max_zone_pfns[i] <= pfn_limit)
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return i;
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}
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return -EPERM;
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}
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/*
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* paging_init() sets up the page tables - in fact we've already done this.
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*/
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void __init paging_init(void)
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{
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unsigned long long total_ram = memblock_phys_mem_size();
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phys_addr_t top_of_ram = memblock_end_of_DRAM();
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#ifdef CONFIG_PPC32
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unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
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unsigned long end = __fix_to_virt(FIX_HOLE);
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for (; v < end; v += PAGE_SIZE)
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map_page(v, 0, 0); /* XXX gross */
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#endif
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#ifdef CONFIG_HIGHMEM
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map_page(PKMAP_BASE, 0, 0); /* XXX gross */
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pkmap_page_table = virt_to_kpte(PKMAP_BASE);
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kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
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kmap_prot = PAGE_KERNEL;
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#endif /* CONFIG_HIGHMEM */
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printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
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(unsigned long long)top_of_ram, total_ram);
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printk(KERN_DEBUG "Memory hole size: %ldMB\n",
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(long int)((top_of_ram - total_ram) >> 20));
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#ifdef CONFIG_HIGHMEM
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limit_zone_pfn(ZONE_NORMAL, lowmem_end_addr >> PAGE_SHIFT);
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#endif
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limit_zone_pfn(TOP_ZONE, top_of_ram >> PAGE_SHIFT);
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zone_limits_final = true;
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free_area_init_nodes(max_zone_pfns);
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mark_nonram_nosave();
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}
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void __init mem_init(void)
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{
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/*
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* book3s is limited to 16 page sizes due to encoding this in
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* a 4-bit field for slices.
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*/
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BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
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#ifdef CONFIG_SWIOTLB
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swiotlb_init(0);
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#endif
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high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
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set_max_mapnr(max_pfn);
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free_all_bootmem();
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#ifdef CONFIG_HIGHMEM
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{
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unsigned long pfn, highmem_mapnr;
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highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
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for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
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phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
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struct page *page = pfn_to_page(pfn);
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if (!memblock_is_reserved(paddr))
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free_highmem_page(page);
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}
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}
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#endif /* CONFIG_HIGHMEM */
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#if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP)
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/*
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* If smp is enabled, next_tlbcam_idx is initialized in the cpu up
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* functions.... do it here for the non-smp case.
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*/
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per_cpu(next_tlbcam_idx, smp_processor_id()) =
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(mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
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#endif
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mem_init_print_info(NULL);
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#ifdef CONFIG_PPC32
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pr_info("Kernel virtual memory layout:\n");
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pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP);
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#ifdef CONFIG_HIGHMEM
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pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n",
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PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
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#endif /* CONFIG_HIGHMEM */
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#ifdef CONFIG_NOT_COHERENT_CACHE
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pr_info(" * 0x%08lx..0x%08lx : consistent mem\n",
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IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE);
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#endif /* CONFIG_NOT_COHERENT_CACHE */
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pr_info(" * 0x%08lx..0x%08lx : early ioremap\n",
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ioremap_bot, IOREMAP_TOP);
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pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n",
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VMALLOC_START, VMALLOC_END);
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#endif /* CONFIG_PPC32 */
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}
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void free_initmem(void)
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{
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ppc_md.progress = ppc_printk_progress;
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free_initmem_default(POISON_FREE_INITMEM);
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}
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#ifdef CONFIG_BLK_DEV_INITRD
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void __init free_initrd_mem(unsigned long start, unsigned long end)
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{
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free_reserved_area((void *)start, (void *)end, -1, "initrd");
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}
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#endif
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/*
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* This is called when a page has been modified by the kernel.
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* It just marks the page as not i-cache clean. We do the i-cache
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* flush later when the page is given to a user process, if necessary.
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*/
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void flush_dcache_page(struct page *page)
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{
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if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
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return;
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/* avoid an atomic op if possible */
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if (test_bit(PG_arch_1, &page->flags))
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clear_bit(PG_arch_1, &page->flags);
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}
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EXPORT_SYMBOL(flush_dcache_page);
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void flush_dcache_icache_page(struct page *page)
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{
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#ifdef CONFIG_HUGETLB_PAGE
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if (PageCompound(page)) {
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flush_dcache_icache_hugepage(page);
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return;
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}
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#endif
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#if defined(CONFIG_8xx) || defined(CONFIG_PPC64)
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/* On 8xx there is no need to kmap since highmem is not supported */
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__flush_dcache_icache(page_address(page));
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#else
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if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) {
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void *start = kmap_atomic(page);
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__flush_dcache_icache(start);
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kunmap_atomic(start);
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} else {
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__flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
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}
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#endif
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}
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EXPORT_SYMBOL(flush_dcache_icache_page);
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void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
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{
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clear_page(page);
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/*
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* We shouldn't have to do this, but some versions of glibc
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* require it (ld.so assumes zero filled pages are icache clean)
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* - Anton
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*/
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flush_dcache_page(pg);
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}
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EXPORT_SYMBOL(clear_user_page);
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void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
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struct page *pg)
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{
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copy_page(vto, vfrom);
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/*
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* We should be able to use the following optimisation, however
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* there are two problems.
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* Firstly a bug in some versions of binutils meant PLT sections
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* were not marked executable.
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* Secondly the first word in the GOT section is blrl, used
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* to establish the GOT address. Until recently the GOT was
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* not marked executable.
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* - Anton
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*/
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#if 0
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if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
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return;
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#endif
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flush_dcache_page(pg);
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}
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void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
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unsigned long addr, int len)
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{
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unsigned long maddr;
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|
|
|
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())
|
|
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 */
|