385 lines
8.5 KiB
C
385 lines
8.5 KiB
C
/*
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* arch/s390/mm/vmem.c
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*
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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 <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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if (slab_is_available())
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return (void *)__get_free_pages(GFP_KERNEL, order);
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return alloc_bootmem_pages((1 << order) * PAGE_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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#ifdef CONFIG_64BIT
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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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#endif
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return pud;
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}
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static inline pmd_t *vmem_pmd_alloc(void)
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{
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pmd_t *pmd = NULL;
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#ifdef CONFIG_64BIT
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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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#endif
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return pmd;
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}
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static 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(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_TYPE_EMPTY,
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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, int ro)
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{
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unsigned long address;
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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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pte_t pte;
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int ret = -ENOMEM;
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for (address = start; address < start + size; address += PAGE_SIZE) {
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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_kernel(&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_kernel(&init_mm, pu_dir, pm_dir);
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}
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pte = mk_pte_phys(address, __pgprot(ro ? _PAGE_RO : 0));
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pm_dir = pmd_offset(pu_dir, address);
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#ifdef __s390x__
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if (MACHINE_HAS_HPAGE && !(address & ~HPAGE_MASK) &&
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(address + HPAGE_SIZE <= start + size) &&
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(address >= HPAGE_SIZE)) {
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pte_val(pte) |= _SEGMENT_ENTRY_LARGE;
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pmd_val(*pm_dir) = pte_val(pte);
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address += HPAGE_SIZE - PAGE_SIZE;
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continue;
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}
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#endif
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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_kernel(&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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*pt_dir = pte;
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}
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ret = 0;
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out:
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flush_tlb_kernel_range(start, start + size);
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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 address;
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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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pte_t pte;
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pte_val(pte) = _PAGE_TYPE_EMPTY;
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for (address = start; address < start + size; address += PAGE_SIZE) {
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pg_dir = pgd_offset_k(address);
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pu_dir = pud_offset(pg_dir, address);
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if (pud_none(*pu_dir))
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continue;
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pm_dir = pmd_offset(pu_dir, address);
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if (pmd_none(*pm_dir))
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continue;
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if (pmd_huge(*pm_dir)) {
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pmd_clear_kernel(pm_dir);
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address += HPAGE_SIZE - PAGE_SIZE;
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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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*pt_dir = pte;
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}
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flush_tlb_kernel_range(start, start + size);
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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(struct page *start, unsigned long nr, int node)
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{
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unsigned long address, start_addr, end_addr;
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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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pte_t pte;
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int ret = -ENOMEM;
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start_addr = (unsigned long) start;
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end_addr = (unsigned long) (start + nr);
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for (address = start_addr; address < end_addr; address += PAGE_SIZE) {
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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_kernel(&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_kernel(&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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pt_dir = vmem_pte_alloc();
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if (!pt_dir)
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goto out;
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pmd_populate_kernel(&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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if (pte_none(*pt_dir)) {
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unsigned long new_page;
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new_page =__pa(vmem_alloc_pages(0));
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if (!new_page)
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goto out;
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pte = pfn_pte(new_page >> PAGE_SHIFT, PAGE_KERNEL);
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*pt_dir = pte;
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}
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}
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memset(start, 0, nr * sizeof(struct page));
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ret = 0;
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out:
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flush_tlb_kernel_range(start_addr, end_addr);
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return ret;
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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, 0);
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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 ro_start, ro_end;
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unsigned long start, end;
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int i;
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INIT_LIST_HEAD(&init_mm.context.crst_list);
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INIT_LIST_HEAD(&init_mm.context.pgtable_list);
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init_mm.context.noexec = 0;
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ro_start = ((unsigned long)&_stext) & PAGE_MASK;
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ro_end = PFN_ALIGN((unsigned long)&_eshared);
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for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
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start = memory_chunk[i].addr;
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end = memory_chunk[i].addr + memory_chunk[i].size;
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if (start >= ro_end || end <= ro_start)
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vmem_add_mem(start, end - start, 0);
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else if (start >= ro_start && end <= ro_end)
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vmem_add_mem(start, end - start, 1);
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else if (start >= ro_start) {
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vmem_add_mem(start, ro_end - start, 1);
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vmem_add_mem(ro_end, end - ro_end, 0);
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} else if (end < ro_end) {
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vmem_add_mem(start, ro_start - start, 0);
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vmem_add_mem(ro_start, end - ro_start, 1);
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} else {
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vmem_add_mem(start, ro_start - start, 0);
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vmem_add_mem(ro_start, ro_end - ro_start, 1);
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vmem_add_mem(ro_end, end - ro_end, 0);
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}
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}
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}
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/*
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* Convert memory chunk array to a memory segment list so there is a single
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* list that contains both r/w memory and shared 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 memory_segment *seg;
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int i;
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mutex_lock(&vmem_mutex);
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for (i = 0; i < MEMORY_CHUNKS; i++) {
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if (!memory_chunk[i].size)
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continue;
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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 = memory_chunk[i].addr;
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seg->size = memory_chunk[i].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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