407 lines
9 KiB
C
407 lines
9 KiB
C
/*
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* Copyright IBM Corp. 2006
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* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
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*/
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#include <linux/bootmem.h>
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#include <linux/pfn.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/list.h>
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#include <linux/hugetlb.h>
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#include <linux/slab.h>
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#include <linux/memblock.h>
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#include <asm/cacheflush.h>
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#include <asm/pgalloc.h>
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#include <asm/pgtable.h>
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#include <asm/setup.h>
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#include <asm/tlbflush.h>
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#include <asm/sections.h>
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static DEFINE_MUTEX(vmem_mutex);
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struct memory_segment {
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struct list_head list;
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unsigned long start;
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unsigned long size;
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};
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static LIST_HEAD(mem_segs);
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static void __ref *vmem_alloc_pages(unsigned int order)
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{
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unsigned long size = PAGE_SIZE << order;
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if (slab_is_available())
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return (void *)__get_free_pages(GFP_KERNEL, order);
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return alloc_bootmem_align(size, size);
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}
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static inline pud_t *vmem_pud_alloc(void)
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{
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pud_t *pud = NULL;
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pud = vmem_alloc_pages(2);
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if (!pud)
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return NULL;
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clear_table((unsigned long *) pud, _REGION3_ENTRY_EMPTY, PAGE_SIZE * 4);
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return pud;
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}
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pmd_t *vmem_pmd_alloc(void)
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{
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pmd_t *pmd = NULL;
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pmd = vmem_alloc_pages(2);
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if (!pmd)
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return NULL;
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clear_table((unsigned long *) pmd, _SEGMENT_ENTRY_EMPTY, PAGE_SIZE * 4);
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return pmd;
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}
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pte_t __ref *vmem_pte_alloc(void)
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{
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pte_t *pte;
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if (slab_is_available())
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pte = (pte_t *) page_table_alloc(&init_mm);
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else
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pte = alloc_bootmem_align(PTRS_PER_PTE * sizeof(pte_t),
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PTRS_PER_PTE * sizeof(pte_t));
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if (!pte)
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return NULL;
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clear_table((unsigned long *) pte, _PAGE_INVALID,
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PTRS_PER_PTE * sizeof(pte_t));
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return pte;
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}
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/*
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* Add a physical memory range to the 1:1 mapping.
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*/
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static int vmem_add_mem(unsigned long start, unsigned long size)
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{
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unsigned long pages4k, pages1m, pages2g;
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unsigned long end = start + size;
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unsigned long address = start;
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pgd_t *pg_dir;
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pud_t *pu_dir;
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pmd_t *pm_dir;
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pte_t *pt_dir;
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int ret = -ENOMEM;
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pages4k = pages1m = pages2g = 0;
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while (address < end) {
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pg_dir = pgd_offset_k(address);
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if (pgd_none(*pg_dir)) {
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pu_dir = vmem_pud_alloc();
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if (!pu_dir)
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goto out;
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pgd_populate(&init_mm, pg_dir, pu_dir);
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}
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pu_dir = pud_offset(pg_dir, address);
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if (MACHINE_HAS_EDAT2 && pud_none(*pu_dir) && address &&
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!(address & ~PUD_MASK) && (address + PUD_SIZE <= end) &&
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!debug_pagealloc_enabled()) {
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pud_val(*pu_dir) = address | pgprot_val(REGION3_KERNEL);
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address += PUD_SIZE;
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pages2g++;
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continue;
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}
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if (pud_none(*pu_dir)) {
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pm_dir = vmem_pmd_alloc();
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if (!pm_dir)
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goto out;
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pud_populate(&init_mm, pu_dir, pm_dir);
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}
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pm_dir = pmd_offset(pu_dir, address);
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if (MACHINE_HAS_EDAT1 && pmd_none(*pm_dir) && address &&
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!(address & ~PMD_MASK) && (address + PMD_SIZE <= end) &&
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!debug_pagealloc_enabled()) {
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pmd_val(*pm_dir) = address | pgprot_val(SEGMENT_KERNEL);
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address += PMD_SIZE;
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pages1m++;
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continue;
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}
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if (pmd_none(*pm_dir)) {
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pt_dir = vmem_pte_alloc();
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if (!pt_dir)
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goto out;
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pmd_populate(&init_mm, pm_dir, pt_dir);
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}
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pt_dir = pte_offset_kernel(pm_dir, address);
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pte_val(*pt_dir) = address | pgprot_val(PAGE_KERNEL);
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address += PAGE_SIZE;
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pages4k++;
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}
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ret = 0;
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out:
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update_page_count(PG_DIRECT_MAP_4K, pages4k);
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update_page_count(PG_DIRECT_MAP_1M, pages1m);
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update_page_count(PG_DIRECT_MAP_2G, pages2g);
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return ret;
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}
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/*
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* Remove a physical memory range from the 1:1 mapping.
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* Currently only invalidates page table entries.
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*/
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static void vmem_remove_range(unsigned long start, unsigned long size)
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{
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unsigned long pages4k, pages1m, pages2g;
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unsigned long end = start + size;
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unsigned long address = start;
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pgd_t *pg_dir;
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pud_t *pu_dir;
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pmd_t *pm_dir;
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pte_t *pt_dir;
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pages4k = pages1m = pages2g = 0;
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while (address < end) {
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pg_dir = pgd_offset_k(address);
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if (pgd_none(*pg_dir)) {
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address += PGDIR_SIZE;
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continue;
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}
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pu_dir = pud_offset(pg_dir, address);
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if (pud_none(*pu_dir)) {
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address += PUD_SIZE;
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continue;
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}
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if (pud_large(*pu_dir)) {
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pud_clear(pu_dir);
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address += PUD_SIZE;
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pages2g++;
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continue;
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}
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pm_dir = pmd_offset(pu_dir, address);
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if (pmd_none(*pm_dir)) {
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address += PMD_SIZE;
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continue;
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}
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if (pmd_large(*pm_dir)) {
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pmd_clear(pm_dir);
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address += PMD_SIZE;
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pages1m++;
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continue;
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}
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pt_dir = pte_offset_kernel(pm_dir, address);
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pte_clear(&init_mm, address, pt_dir);
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address += PAGE_SIZE;
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pages4k++;
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}
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flush_tlb_kernel_range(start, end);
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update_page_count(PG_DIRECT_MAP_4K, -pages4k);
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update_page_count(PG_DIRECT_MAP_1M, -pages1m);
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update_page_count(PG_DIRECT_MAP_2G, -pages2g);
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}
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/*
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* Add a backed mem_map array to the virtual mem_map array.
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*/
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int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
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{
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unsigned long address = start;
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pgd_t *pg_dir;
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pud_t *pu_dir;
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pmd_t *pm_dir;
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pte_t *pt_dir;
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int ret = -ENOMEM;
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for (address = start; address < end;) {
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pg_dir = pgd_offset_k(address);
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if (pgd_none(*pg_dir)) {
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pu_dir = vmem_pud_alloc();
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if (!pu_dir)
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goto out;
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pgd_populate(&init_mm, pg_dir, pu_dir);
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}
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pu_dir = pud_offset(pg_dir, address);
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if (pud_none(*pu_dir)) {
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pm_dir = vmem_pmd_alloc();
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if (!pm_dir)
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goto out;
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pud_populate(&init_mm, pu_dir, pm_dir);
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}
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pm_dir = pmd_offset(pu_dir, address);
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if (pmd_none(*pm_dir)) {
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/* Use 1MB frames for vmemmap if available. We always
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* use large frames even if they are only partially
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* used.
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* Otherwise we would have also page tables since
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* vmemmap_populate gets called for each section
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* separately. */
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if (MACHINE_HAS_EDAT1) {
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void *new_page;
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new_page = vmemmap_alloc_block(PMD_SIZE, node);
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if (!new_page)
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goto out;
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pmd_val(*pm_dir) = __pa(new_page) |
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_SEGMENT_ENTRY | _SEGMENT_ENTRY_LARGE;
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address = (address + PMD_SIZE) & PMD_MASK;
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continue;
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}
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pt_dir = vmem_pte_alloc();
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if (!pt_dir)
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goto out;
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pmd_populate(&init_mm, pm_dir, pt_dir);
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} else if (pmd_large(*pm_dir)) {
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address = (address + PMD_SIZE) & PMD_MASK;
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continue;
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}
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pt_dir = pte_offset_kernel(pm_dir, address);
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if (pte_none(*pt_dir)) {
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void *new_page;
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new_page = vmemmap_alloc_block(PAGE_SIZE, node);
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if (!new_page)
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goto out;
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pte_val(*pt_dir) =
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__pa(new_page) | pgprot_val(PAGE_KERNEL);
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}
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address += PAGE_SIZE;
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}
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ret = 0;
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out:
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return ret;
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}
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void vmemmap_free(unsigned long start, unsigned long end)
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{
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}
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/*
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* Add memory segment to the segment list if it doesn't overlap with
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* an already present segment.
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*/
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static int insert_memory_segment(struct memory_segment *seg)
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{
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struct memory_segment *tmp;
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if (seg->start + seg->size > VMEM_MAX_PHYS ||
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seg->start + seg->size < seg->start)
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return -ERANGE;
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list_for_each_entry(tmp, &mem_segs, list) {
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if (seg->start >= tmp->start + tmp->size)
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continue;
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if (seg->start + seg->size <= tmp->start)
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continue;
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return -ENOSPC;
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}
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list_add(&seg->list, &mem_segs);
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return 0;
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}
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/*
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* Remove memory segment from the segment list.
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*/
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static void remove_memory_segment(struct memory_segment *seg)
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{
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list_del(&seg->list);
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}
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static void __remove_shared_memory(struct memory_segment *seg)
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{
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remove_memory_segment(seg);
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vmem_remove_range(seg->start, seg->size);
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}
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int vmem_remove_mapping(unsigned long start, unsigned long size)
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{
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struct memory_segment *seg;
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int ret;
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mutex_lock(&vmem_mutex);
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ret = -ENOENT;
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list_for_each_entry(seg, &mem_segs, list) {
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if (seg->start == start && seg->size == size)
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break;
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}
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if (seg->start != start || seg->size != size)
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goto out;
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ret = 0;
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__remove_shared_memory(seg);
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kfree(seg);
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out:
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mutex_unlock(&vmem_mutex);
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return ret;
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}
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int vmem_add_mapping(unsigned long start, unsigned long size)
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{
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struct memory_segment *seg;
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int ret;
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mutex_lock(&vmem_mutex);
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ret = -ENOMEM;
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seg = kzalloc(sizeof(*seg), GFP_KERNEL);
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if (!seg)
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goto out;
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seg->start = start;
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seg->size = size;
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ret = insert_memory_segment(seg);
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if (ret)
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goto out_free;
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ret = vmem_add_mem(start, size);
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if (ret)
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goto out_remove;
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goto out;
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out_remove:
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__remove_shared_memory(seg);
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out_free:
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kfree(seg);
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out:
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mutex_unlock(&vmem_mutex);
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return ret;
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}
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/*
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* map whole physical memory to virtual memory (identity mapping)
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* we reserve enough space in the vmalloc area for vmemmap to hotplug
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* additional memory segments.
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*/
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void __init vmem_map_init(void)
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{
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unsigned long size = _eshared - _stext;
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struct memblock_region *reg;
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for_each_memblock(memory, reg)
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vmem_add_mem(reg->base, reg->size);
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set_memory_ro((unsigned long)_stext, size >> PAGE_SHIFT);
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pr_info("Write protected kernel read-only data: %luk\n", size >> 10);
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}
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/*
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* Convert memblock.memory to a memory segment list so there is a single
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* list that contains all memory segments.
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*/
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static int __init vmem_convert_memory_chunk(void)
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{
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struct memblock_region *reg;
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struct memory_segment *seg;
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mutex_lock(&vmem_mutex);
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for_each_memblock(memory, reg) {
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seg = kzalloc(sizeof(*seg), GFP_KERNEL);
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if (!seg)
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panic("Out of memory...\n");
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seg->start = reg->base;
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seg->size = reg->size;
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insert_memory_segment(seg);
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}
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mutex_unlock(&vmem_mutex);
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return 0;
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}
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core_initcall(vmem_convert_memory_chunk);
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