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![Heiko Carstens](/assets/img/avatar_default.png)
Fix name clash with user_mode() define which is also used in common code. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
868 lines
23 KiB
C
868 lines
23 KiB
C
/*
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* Copyright IBM Corp. 2007, 2011
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* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
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*/
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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/gfp.h>
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#include <linux/mm.h>
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#include <linux/swap.h>
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#include <linux/smp.h>
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#include <linux/highmem.h>
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#include <linux/pagemap.h>
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#include <linux/spinlock.h>
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#include <linux/module.h>
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#include <linux/quicklist.h>
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#include <linux/rcupdate.h>
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#include <linux/slab.h>
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#include <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <asm/tlb.h>
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#include <asm/tlbflush.h>
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#include <asm/mmu_context.h>
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#ifndef CONFIG_64BIT
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#define ALLOC_ORDER 1
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#define FRAG_MASK 0x0f
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#else
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#define ALLOC_ORDER 2
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#define FRAG_MASK 0x03
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#endif
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unsigned long *crst_table_alloc(struct mm_struct *mm)
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{
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struct page *page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
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if (!page)
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return NULL;
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return (unsigned long *) page_to_phys(page);
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}
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void crst_table_free(struct mm_struct *mm, unsigned long *table)
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{
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free_pages((unsigned long) table, ALLOC_ORDER);
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}
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#ifdef CONFIG_64BIT
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int crst_table_upgrade(struct mm_struct *mm, unsigned long limit)
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{
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unsigned long *table, *pgd;
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unsigned long entry;
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BUG_ON(limit > (1UL << 53));
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repeat:
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table = crst_table_alloc(mm);
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if (!table)
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return -ENOMEM;
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spin_lock_bh(&mm->page_table_lock);
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if (mm->context.asce_limit < limit) {
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pgd = (unsigned long *) mm->pgd;
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if (mm->context.asce_limit <= (1UL << 31)) {
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entry = _REGION3_ENTRY_EMPTY;
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mm->context.asce_limit = 1UL << 42;
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mm->context.asce_bits = _ASCE_TABLE_LENGTH |
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_ASCE_USER_BITS |
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_ASCE_TYPE_REGION3;
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} else {
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entry = _REGION2_ENTRY_EMPTY;
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mm->context.asce_limit = 1UL << 53;
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mm->context.asce_bits = _ASCE_TABLE_LENGTH |
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_ASCE_USER_BITS |
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_ASCE_TYPE_REGION2;
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}
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crst_table_init(table, entry);
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pgd_populate(mm, (pgd_t *) table, (pud_t *) pgd);
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mm->pgd = (pgd_t *) table;
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mm->task_size = mm->context.asce_limit;
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table = NULL;
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}
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spin_unlock_bh(&mm->page_table_lock);
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if (table)
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crst_table_free(mm, table);
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if (mm->context.asce_limit < limit)
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goto repeat;
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return 0;
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}
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void crst_table_downgrade(struct mm_struct *mm, unsigned long limit)
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{
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pgd_t *pgd;
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while (mm->context.asce_limit > limit) {
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pgd = mm->pgd;
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switch (pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) {
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case _REGION_ENTRY_TYPE_R2:
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mm->context.asce_limit = 1UL << 42;
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mm->context.asce_bits = _ASCE_TABLE_LENGTH |
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_ASCE_USER_BITS |
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_ASCE_TYPE_REGION3;
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break;
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case _REGION_ENTRY_TYPE_R3:
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mm->context.asce_limit = 1UL << 31;
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mm->context.asce_bits = _ASCE_TABLE_LENGTH |
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_ASCE_USER_BITS |
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_ASCE_TYPE_SEGMENT;
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break;
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default:
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BUG();
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}
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mm->pgd = (pgd_t *) (pgd_val(*pgd) & _REGION_ENTRY_ORIGIN);
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mm->task_size = mm->context.asce_limit;
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crst_table_free(mm, (unsigned long *) pgd);
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}
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}
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#endif
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#ifdef CONFIG_PGSTE
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/**
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* gmap_alloc - allocate a guest address space
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* @mm: pointer to the parent mm_struct
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*
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* Returns a guest address space structure.
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*/
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struct gmap *gmap_alloc(struct mm_struct *mm)
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{
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struct gmap *gmap;
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struct page *page;
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unsigned long *table;
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gmap = kzalloc(sizeof(struct gmap), GFP_KERNEL);
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if (!gmap)
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goto out;
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INIT_LIST_HEAD(&gmap->crst_list);
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gmap->mm = mm;
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page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
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if (!page)
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goto out_free;
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list_add(&page->lru, &gmap->crst_list);
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table = (unsigned long *) page_to_phys(page);
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crst_table_init(table, _REGION1_ENTRY_EMPTY);
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gmap->table = table;
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gmap->asce = _ASCE_TYPE_REGION1 | _ASCE_TABLE_LENGTH |
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_ASCE_USER_BITS | __pa(table);
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list_add(&gmap->list, &mm->context.gmap_list);
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return gmap;
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out_free:
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kfree(gmap);
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out:
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return NULL;
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}
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EXPORT_SYMBOL_GPL(gmap_alloc);
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static int gmap_unlink_segment(struct gmap *gmap, unsigned long *table)
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{
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struct gmap_pgtable *mp;
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struct gmap_rmap *rmap;
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struct page *page;
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if (*table & _SEGMENT_ENTRY_INV)
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return 0;
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page = pfn_to_page(*table >> PAGE_SHIFT);
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mp = (struct gmap_pgtable *) page->index;
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list_for_each_entry(rmap, &mp->mapper, list) {
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if (rmap->entry != table)
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continue;
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list_del(&rmap->list);
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kfree(rmap);
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break;
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}
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*table = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO | mp->vmaddr;
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return 1;
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}
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static void gmap_flush_tlb(struct gmap *gmap)
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{
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if (MACHINE_HAS_IDTE)
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__tlb_flush_idte((unsigned long) gmap->table |
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_ASCE_TYPE_REGION1);
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else
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__tlb_flush_global();
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}
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/**
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* gmap_free - free a guest address space
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* @gmap: pointer to the guest address space structure
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*/
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void gmap_free(struct gmap *gmap)
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{
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struct page *page, *next;
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unsigned long *table;
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int i;
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/* Flush tlb. */
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if (MACHINE_HAS_IDTE)
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__tlb_flush_idte((unsigned long) gmap->table |
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_ASCE_TYPE_REGION1);
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else
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__tlb_flush_global();
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/* Free all segment & region tables. */
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down_read(&gmap->mm->mmap_sem);
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spin_lock(&gmap->mm->page_table_lock);
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list_for_each_entry_safe(page, next, &gmap->crst_list, lru) {
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table = (unsigned long *) page_to_phys(page);
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if ((*table & _REGION_ENTRY_TYPE_MASK) == 0)
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/* Remove gmap rmap structures for segment table. */
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for (i = 0; i < PTRS_PER_PMD; i++, table++)
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gmap_unlink_segment(gmap, table);
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__free_pages(page, ALLOC_ORDER);
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}
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spin_unlock(&gmap->mm->page_table_lock);
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up_read(&gmap->mm->mmap_sem);
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list_del(&gmap->list);
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kfree(gmap);
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}
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EXPORT_SYMBOL_GPL(gmap_free);
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/**
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* gmap_enable - switch primary space to the guest address space
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* @gmap: pointer to the guest address space structure
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*/
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void gmap_enable(struct gmap *gmap)
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{
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S390_lowcore.gmap = (unsigned long) gmap;
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}
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EXPORT_SYMBOL_GPL(gmap_enable);
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/**
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* gmap_disable - switch back to the standard primary address space
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* @gmap: pointer to the guest address space structure
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*/
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void gmap_disable(struct gmap *gmap)
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{
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S390_lowcore.gmap = 0UL;
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}
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EXPORT_SYMBOL_GPL(gmap_disable);
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/*
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* gmap_alloc_table is assumed to be called with mmap_sem held
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*/
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static int gmap_alloc_table(struct gmap *gmap,
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unsigned long *table, unsigned long init)
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{
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struct page *page;
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unsigned long *new;
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/* since we dont free the gmap table until gmap_free we can unlock */
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spin_unlock(&gmap->mm->page_table_lock);
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page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
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spin_lock(&gmap->mm->page_table_lock);
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if (!page)
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return -ENOMEM;
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new = (unsigned long *) page_to_phys(page);
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crst_table_init(new, init);
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if (*table & _REGION_ENTRY_INV) {
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list_add(&page->lru, &gmap->crst_list);
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*table = (unsigned long) new | _REGION_ENTRY_LENGTH |
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(*table & _REGION_ENTRY_TYPE_MASK);
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} else
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__free_pages(page, ALLOC_ORDER);
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return 0;
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}
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/**
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* gmap_unmap_segment - unmap segment from the guest address space
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* @gmap: pointer to the guest address space structure
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* @addr: address in the guest address space
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* @len: length of the memory area to unmap
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*
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* Returns 0 if the unmap succeded, -EINVAL if not.
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*/
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int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len)
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{
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unsigned long *table;
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unsigned long off;
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int flush;
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if ((to | len) & (PMD_SIZE - 1))
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return -EINVAL;
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if (len == 0 || to + len < to)
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return -EINVAL;
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flush = 0;
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down_read(&gmap->mm->mmap_sem);
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spin_lock(&gmap->mm->page_table_lock);
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for (off = 0; off < len; off += PMD_SIZE) {
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/* Walk the guest addr space page table */
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table = gmap->table + (((to + off) >> 53) & 0x7ff);
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if (*table & _REGION_ENTRY_INV)
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goto out;
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table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
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table = table + (((to + off) >> 42) & 0x7ff);
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if (*table & _REGION_ENTRY_INV)
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goto out;
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table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
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table = table + (((to + off) >> 31) & 0x7ff);
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if (*table & _REGION_ENTRY_INV)
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goto out;
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table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
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table = table + (((to + off) >> 20) & 0x7ff);
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/* Clear segment table entry in guest address space. */
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flush |= gmap_unlink_segment(gmap, table);
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*table = _SEGMENT_ENTRY_INV;
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}
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out:
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spin_unlock(&gmap->mm->page_table_lock);
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up_read(&gmap->mm->mmap_sem);
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if (flush)
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gmap_flush_tlb(gmap);
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return 0;
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}
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EXPORT_SYMBOL_GPL(gmap_unmap_segment);
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/**
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* gmap_mmap_segment - map a segment to the guest address space
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* @gmap: pointer to the guest address space structure
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* @from: source address in the parent address space
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* @to: target address in the guest address space
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*
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* Returns 0 if the mmap succeded, -EINVAL or -ENOMEM if not.
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*/
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int gmap_map_segment(struct gmap *gmap, unsigned long from,
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unsigned long to, unsigned long len)
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{
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unsigned long *table;
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unsigned long off;
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int flush;
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if ((from | to | len) & (PMD_SIZE - 1))
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return -EINVAL;
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if (len == 0 || from + len > PGDIR_SIZE ||
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from + len < from || to + len < to)
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return -EINVAL;
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flush = 0;
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down_read(&gmap->mm->mmap_sem);
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spin_lock(&gmap->mm->page_table_lock);
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for (off = 0; off < len; off += PMD_SIZE) {
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/* Walk the gmap address space page table */
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table = gmap->table + (((to + off) >> 53) & 0x7ff);
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if ((*table & _REGION_ENTRY_INV) &&
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gmap_alloc_table(gmap, table, _REGION2_ENTRY_EMPTY))
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goto out_unmap;
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table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
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table = table + (((to + off) >> 42) & 0x7ff);
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if ((*table & _REGION_ENTRY_INV) &&
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gmap_alloc_table(gmap, table, _REGION3_ENTRY_EMPTY))
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goto out_unmap;
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table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
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table = table + (((to + off) >> 31) & 0x7ff);
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if ((*table & _REGION_ENTRY_INV) &&
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gmap_alloc_table(gmap, table, _SEGMENT_ENTRY_EMPTY))
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goto out_unmap;
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table = (unsigned long *) (*table & _REGION_ENTRY_ORIGIN);
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table = table + (((to + off) >> 20) & 0x7ff);
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/* Store 'from' address in an invalid segment table entry. */
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flush |= gmap_unlink_segment(gmap, table);
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*table = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO | (from + off);
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}
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spin_unlock(&gmap->mm->page_table_lock);
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up_read(&gmap->mm->mmap_sem);
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if (flush)
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gmap_flush_tlb(gmap);
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return 0;
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out_unmap:
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spin_unlock(&gmap->mm->page_table_lock);
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up_read(&gmap->mm->mmap_sem);
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gmap_unmap_segment(gmap, to, len);
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return -ENOMEM;
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}
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EXPORT_SYMBOL_GPL(gmap_map_segment);
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/*
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* this function is assumed to be called with mmap_sem held
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*/
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unsigned long __gmap_fault(unsigned long address, struct gmap *gmap)
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{
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unsigned long *table, vmaddr, segment;
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struct mm_struct *mm;
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struct gmap_pgtable *mp;
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struct gmap_rmap *rmap;
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struct vm_area_struct *vma;
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struct page *page;
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmd;
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current->thread.gmap_addr = address;
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mm = gmap->mm;
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/* Walk the gmap address space page table */
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table = gmap->table + ((address >> 53) & 0x7ff);
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if (unlikely(*table & _REGION_ENTRY_INV))
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return -EFAULT;
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table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
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table = table + ((address >> 42) & 0x7ff);
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if (unlikely(*table & _REGION_ENTRY_INV))
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return -EFAULT;
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table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
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table = table + ((address >> 31) & 0x7ff);
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if (unlikely(*table & _REGION_ENTRY_INV))
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return -EFAULT;
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table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
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table = table + ((address >> 20) & 0x7ff);
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/* Convert the gmap address to an mm address. */
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segment = *table;
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if (likely(!(segment & _SEGMENT_ENTRY_INV))) {
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page = pfn_to_page(segment >> PAGE_SHIFT);
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mp = (struct gmap_pgtable *) page->index;
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return mp->vmaddr | (address & ~PMD_MASK);
|
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} else if (segment & _SEGMENT_ENTRY_RO) {
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vmaddr = segment & _SEGMENT_ENTRY_ORIGIN;
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vma = find_vma(mm, vmaddr);
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if (!vma || vma->vm_start > vmaddr)
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return -EFAULT;
|
|
|
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/* Walk the parent mm page table */
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pgd = pgd_offset(mm, vmaddr);
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pud = pud_alloc(mm, pgd, vmaddr);
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if (!pud)
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return -ENOMEM;
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pmd = pmd_alloc(mm, pud, vmaddr);
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if (!pmd)
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return -ENOMEM;
|
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if (!pmd_present(*pmd) &&
|
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__pte_alloc(mm, vma, pmd, vmaddr))
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return -ENOMEM;
|
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/* pmd now points to a valid segment table entry. */
|
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rmap = kmalloc(sizeof(*rmap), GFP_KERNEL|__GFP_REPEAT);
|
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if (!rmap)
|
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return -ENOMEM;
|
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/* Link gmap segment table entry location to page table. */
|
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page = pmd_page(*pmd);
|
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mp = (struct gmap_pgtable *) page->index;
|
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rmap->entry = table;
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spin_lock(&mm->page_table_lock);
|
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list_add(&rmap->list, &mp->mapper);
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spin_unlock(&mm->page_table_lock);
|
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/* Set gmap segment table entry to page table. */
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*table = pmd_val(*pmd) & PAGE_MASK;
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return vmaddr | (address & ~PMD_MASK);
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}
|
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return -EFAULT;
|
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}
|
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|
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unsigned long gmap_fault(unsigned long address, struct gmap *gmap)
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{
|
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unsigned long rc;
|
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|
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down_read(&gmap->mm->mmap_sem);
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rc = __gmap_fault(address, gmap);
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up_read(&gmap->mm->mmap_sem);
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return rc;
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}
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EXPORT_SYMBOL_GPL(gmap_fault);
|
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|
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void gmap_discard(unsigned long from, unsigned long to, struct gmap *gmap)
|
|
{
|
|
|
|
unsigned long *table, address, size;
|
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struct vm_area_struct *vma;
|
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struct gmap_pgtable *mp;
|
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struct page *page;
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|
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down_read(&gmap->mm->mmap_sem);
|
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address = from;
|
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while (address < to) {
|
|
/* Walk the gmap address space page table */
|
|
table = gmap->table + ((address >> 53) & 0x7ff);
|
|
if (unlikely(*table & _REGION_ENTRY_INV)) {
|
|
address = (address + PMD_SIZE) & PMD_MASK;
|
|
continue;
|
|
}
|
|
table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
|
|
table = table + ((address >> 42) & 0x7ff);
|
|
if (unlikely(*table & _REGION_ENTRY_INV)) {
|
|
address = (address + PMD_SIZE) & PMD_MASK;
|
|
continue;
|
|
}
|
|
table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
|
|
table = table + ((address >> 31) & 0x7ff);
|
|
if (unlikely(*table & _REGION_ENTRY_INV)) {
|
|
address = (address + PMD_SIZE) & PMD_MASK;
|
|
continue;
|
|
}
|
|
table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
|
|
table = table + ((address >> 20) & 0x7ff);
|
|
if (unlikely(*table & _SEGMENT_ENTRY_INV)) {
|
|
address = (address + PMD_SIZE) & PMD_MASK;
|
|
continue;
|
|
}
|
|
page = pfn_to_page(*table >> PAGE_SHIFT);
|
|
mp = (struct gmap_pgtable *) page->index;
|
|
vma = find_vma(gmap->mm, mp->vmaddr);
|
|
size = min(to - address, PMD_SIZE - (address & ~PMD_MASK));
|
|
zap_page_range(vma, mp->vmaddr | (address & ~PMD_MASK),
|
|
size, NULL);
|
|
address = (address + PMD_SIZE) & PMD_MASK;
|
|
}
|
|
up_read(&gmap->mm->mmap_sem);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gmap_discard);
|
|
|
|
void gmap_unmap_notifier(struct mm_struct *mm, unsigned long *table)
|
|
{
|
|
struct gmap_rmap *rmap, *next;
|
|
struct gmap_pgtable *mp;
|
|
struct page *page;
|
|
int flush;
|
|
|
|
flush = 0;
|
|
spin_lock(&mm->page_table_lock);
|
|
page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
|
|
mp = (struct gmap_pgtable *) page->index;
|
|
list_for_each_entry_safe(rmap, next, &mp->mapper, list) {
|
|
*rmap->entry =
|
|
_SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO | mp->vmaddr;
|
|
list_del(&rmap->list);
|
|
kfree(rmap);
|
|
flush = 1;
|
|
}
|
|
spin_unlock(&mm->page_table_lock);
|
|
if (flush)
|
|
__tlb_flush_global();
|
|
}
|
|
|
|
static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm,
|
|
unsigned long vmaddr)
|
|
{
|
|
struct page *page;
|
|
unsigned long *table;
|
|
struct gmap_pgtable *mp;
|
|
|
|
page = alloc_page(GFP_KERNEL|__GFP_REPEAT);
|
|
if (!page)
|
|
return NULL;
|
|
mp = kmalloc(sizeof(*mp), GFP_KERNEL|__GFP_REPEAT);
|
|
if (!mp) {
|
|
__free_page(page);
|
|
return NULL;
|
|
}
|
|
pgtable_page_ctor(page);
|
|
mp->vmaddr = vmaddr & PMD_MASK;
|
|
INIT_LIST_HEAD(&mp->mapper);
|
|
page->index = (unsigned long) mp;
|
|
atomic_set(&page->_mapcount, 3);
|
|
table = (unsigned long *) page_to_phys(page);
|
|
clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE/2);
|
|
clear_table(table + PTRS_PER_PTE, 0, PAGE_SIZE/2);
|
|
return table;
|
|
}
|
|
|
|
static inline void page_table_free_pgste(unsigned long *table)
|
|
{
|
|
struct page *page;
|
|
struct gmap_pgtable *mp;
|
|
|
|
page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
|
|
mp = (struct gmap_pgtable *) page->index;
|
|
BUG_ON(!list_empty(&mp->mapper));
|
|
pgtable_page_dtor(page);
|
|
atomic_set(&page->_mapcount, -1);
|
|
kfree(mp);
|
|
__free_page(page);
|
|
}
|
|
|
|
#else /* CONFIG_PGSTE */
|
|
|
|
static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm,
|
|
unsigned long vmaddr)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static inline void page_table_free_pgste(unsigned long *table)
|
|
{
|
|
}
|
|
|
|
static inline void gmap_unmap_notifier(struct mm_struct *mm,
|
|
unsigned long *table)
|
|
{
|
|
}
|
|
|
|
#endif /* CONFIG_PGSTE */
|
|
|
|
static inline unsigned int atomic_xor_bits(atomic_t *v, unsigned int bits)
|
|
{
|
|
unsigned int old, new;
|
|
|
|
do {
|
|
old = atomic_read(v);
|
|
new = old ^ bits;
|
|
} while (atomic_cmpxchg(v, old, new) != old);
|
|
return new;
|
|
}
|
|
|
|
/*
|
|
* page table entry allocation/free routines.
|
|
*/
|
|
unsigned long *page_table_alloc(struct mm_struct *mm, unsigned long vmaddr)
|
|
{
|
|
struct page *page;
|
|
unsigned long *table;
|
|
unsigned int mask, bit;
|
|
|
|
if (mm_has_pgste(mm))
|
|
return page_table_alloc_pgste(mm, vmaddr);
|
|
/* Allocate fragments of a 4K page as 1K/2K page table */
|
|
spin_lock_bh(&mm->context.list_lock);
|
|
mask = FRAG_MASK;
|
|
if (!list_empty(&mm->context.pgtable_list)) {
|
|
page = list_first_entry(&mm->context.pgtable_list,
|
|
struct page, lru);
|
|
table = (unsigned long *) page_to_phys(page);
|
|
mask = atomic_read(&page->_mapcount);
|
|
mask = mask | (mask >> 4);
|
|
}
|
|
if ((mask & FRAG_MASK) == FRAG_MASK) {
|
|
spin_unlock_bh(&mm->context.list_lock);
|
|
page = alloc_page(GFP_KERNEL|__GFP_REPEAT);
|
|
if (!page)
|
|
return NULL;
|
|
pgtable_page_ctor(page);
|
|
atomic_set(&page->_mapcount, 1);
|
|
table = (unsigned long *) page_to_phys(page);
|
|
clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE);
|
|
spin_lock_bh(&mm->context.list_lock);
|
|
list_add(&page->lru, &mm->context.pgtable_list);
|
|
} else {
|
|
for (bit = 1; mask & bit; bit <<= 1)
|
|
table += PTRS_PER_PTE;
|
|
mask = atomic_xor_bits(&page->_mapcount, bit);
|
|
if ((mask & FRAG_MASK) == FRAG_MASK)
|
|
list_del(&page->lru);
|
|
}
|
|
spin_unlock_bh(&mm->context.list_lock);
|
|
return table;
|
|
}
|
|
|
|
void page_table_free(struct mm_struct *mm, unsigned long *table)
|
|
{
|
|
struct page *page;
|
|
unsigned int bit, mask;
|
|
|
|
if (mm_has_pgste(mm)) {
|
|
gmap_unmap_notifier(mm, table);
|
|
return page_table_free_pgste(table);
|
|
}
|
|
/* Free 1K/2K page table fragment of a 4K page */
|
|
page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
|
|
bit = 1 << ((__pa(table) & ~PAGE_MASK)/(PTRS_PER_PTE*sizeof(pte_t)));
|
|
spin_lock_bh(&mm->context.list_lock);
|
|
if ((atomic_read(&page->_mapcount) & FRAG_MASK) != FRAG_MASK)
|
|
list_del(&page->lru);
|
|
mask = atomic_xor_bits(&page->_mapcount, bit);
|
|
if (mask & FRAG_MASK)
|
|
list_add(&page->lru, &mm->context.pgtable_list);
|
|
spin_unlock_bh(&mm->context.list_lock);
|
|
if (mask == 0) {
|
|
pgtable_page_dtor(page);
|
|
atomic_set(&page->_mapcount, -1);
|
|
__free_page(page);
|
|
}
|
|
}
|
|
|
|
static void __page_table_free_rcu(void *table, unsigned bit)
|
|
{
|
|
struct page *page;
|
|
|
|
if (bit == FRAG_MASK)
|
|
return page_table_free_pgste(table);
|
|
/* Free 1K/2K page table fragment of a 4K page */
|
|
page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
|
|
if (atomic_xor_bits(&page->_mapcount, bit) == 0) {
|
|
pgtable_page_dtor(page);
|
|
atomic_set(&page->_mapcount, -1);
|
|
__free_page(page);
|
|
}
|
|
}
|
|
|
|
void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table)
|
|
{
|
|
struct mm_struct *mm;
|
|
struct page *page;
|
|
unsigned int bit, mask;
|
|
|
|
mm = tlb->mm;
|
|
if (mm_has_pgste(mm)) {
|
|
gmap_unmap_notifier(mm, table);
|
|
table = (unsigned long *) (__pa(table) | FRAG_MASK);
|
|
tlb_remove_table(tlb, table);
|
|
return;
|
|
}
|
|
bit = 1 << ((__pa(table) & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t)));
|
|
page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
|
|
spin_lock_bh(&mm->context.list_lock);
|
|
if ((atomic_read(&page->_mapcount) & FRAG_MASK) != FRAG_MASK)
|
|
list_del(&page->lru);
|
|
mask = atomic_xor_bits(&page->_mapcount, bit | (bit << 4));
|
|
if (mask & FRAG_MASK)
|
|
list_add_tail(&page->lru, &mm->context.pgtable_list);
|
|
spin_unlock_bh(&mm->context.list_lock);
|
|
table = (unsigned long *) (__pa(table) | (bit << 4));
|
|
tlb_remove_table(tlb, table);
|
|
}
|
|
|
|
void __tlb_remove_table(void *_table)
|
|
{
|
|
const unsigned long mask = (FRAG_MASK << 4) | FRAG_MASK;
|
|
void *table = (void *)((unsigned long) _table & ~mask);
|
|
unsigned type = (unsigned long) _table & mask;
|
|
|
|
if (type)
|
|
__page_table_free_rcu(table, type);
|
|
else
|
|
free_pages((unsigned long) table, ALLOC_ORDER);
|
|
}
|
|
|
|
static void tlb_remove_table_smp_sync(void *arg)
|
|
{
|
|
/* Simply deliver the interrupt */
|
|
}
|
|
|
|
static void tlb_remove_table_one(void *table)
|
|
{
|
|
/*
|
|
* This isn't an RCU grace period and hence the page-tables cannot be
|
|
* assumed to be actually RCU-freed.
|
|
*
|
|
* It is however sufficient for software page-table walkers that rely
|
|
* on IRQ disabling. See the comment near struct mmu_table_batch.
|
|
*/
|
|
smp_call_function(tlb_remove_table_smp_sync, NULL, 1);
|
|
__tlb_remove_table(table);
|
|
}
|
|
|
|
static void tlb_remove_table_rcu(struct rcu_head *head)
|
|
{
|
|
struct mmu_table_batch *batch;
|
|
int i;
|
|
|
|
batch = container_of(head, struct mmu_table_batch, rcu);
|
|
|
|
for (i = 0; i < batch->nr; i++)
|
|
__tlb_remove_table(batch->tables[i]);
|
|
|
|
free_page((unsigned long)batch);
|
|
}
|
|
|
|
void tlb_table_flush(struct mmu_gather *tlb)
|
|
{
|
|
struct mmu_table_batch **batch = &tlb->batch;
|
|
|
|
if (*batch) {
|
|
__tlb_flush_mm(tlb->mm);
|
|
call_rcu_sched(&(*batch)->rcu, tlb_remove_table_rcu);
|
|
*batch = NULL;
|
|
}
|
|
}
|
|
|
|
void tlb_remove_table(struct mmu_gather *tlb, void *table)
|
|
{
|
|
struct mmu_table_batch **batch = &tlb->batch;
|
|
|
|
if (*batch == NULL) {
|
|
*batch = (struct mmu_table_batch *)
|
|
__get_free_page(GFP_NOWAIT | __GFP_NOWARN);
|
|
if (*batch == NULL) {
|
|
__tlb_flush_mm(tlb->mm);
|
|
tlb_remove_table_one(table);
|
|
return;
|
|
}
|
|
(*batch)->nr = 0;
|
|
}
|
|
(*batch)->tables[(*batch)->nr++] = table;
|
|
if ((*batch)->nr == MAX_TABLE_BATCH)
|
|
tlb_table_flush(tlb);
|
|
}
|
|
|
|
/*
|
|
* switch on pgstes for its userspace process (for kvm)
|
|
*/
|
|
int s390_enable_sie(void)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
struct mm_struct *mm, *old_mm;
|
|
|
|
/* Do we have switched amode? If no, we cannot do sie */
|
|
if (addressing_mode == HOME_SPACE_MODE)
|
|
return -EINVAL;
|
|
|
|
/* Do we have pgstes? if yes, we are done */
|
|
if (mm_has_pgste(tsk->mm))
|
|
return 0;
|
|
|
|
/* lets check if we are allowed to replace the mm */
|
|
task_lock(tsk);
|
|
if (!tsk->mm || atomic_read(&tsk->mm->mm_users) > 1 ||
|
|
#ifdef CONFIG_AIO
|
|
!hlist_empty(&tsk->mm->ioctx_list) ||
|
|
#endif
|
|
tsk->mm != tsk->active_mm) {
|
|
task_unlock(tsk);
|
|
return -EINVAL;
|
|
}
|
|
task_unlock(tsk);
|
|
|
|
/* we copy the mm and let dup_mm create the page tables with_pgstes */
|
|
tsk->mm->context.alloc_pgste = 1;
|
|
/* make sure that both mms have a correct rss state */
|
|
sync_mm_rss(tsk->mm);
|
|
mm = dup_mm(tsk);
|
|
tsk->mm->context.alloc_pgste = 0;
|
|
if (!mm)
|
|
return -ENOMEM;
|
|
|
|
/* Now lets check again if something happened */
|
|
task_lock(tsk);
|
|
if (!tsk->mm || atomic_read(&tsk->mm->mm_users) > 1 ||
|
|
#ifdef CONFIG_AIO
|
|
!hlist_empty(&tsk->mm->ioctx_list) ||
|
|
#endif
|
|
tsk->mm != tsk->active_mm) {
|
|
mmput(mm);
|
|
task_unlock(tsk);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* ok, we are alone. No ptrace, no threads, etc. */
|
|
old_mm = tsk->mm;
|
|
tsk->mm = tsk->active_mm = mm;
|
|
preempt_disable();
|
|
update_mm(mm, tsk);
|
|
atomic_inc(&mm->context.attach_count);
|
|
atomic_dec(&old_mm->context.attach_count);
|
|
cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm));
|
|
preempt_enable();
|
|
task_unlock(tsk);
|
|
mmput(old_mm);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(s390_enable_sie);
|
|
|
|
#if defined(CONFIG_DEBUG_PAGEALLOC) && defined(CONFIG_HIBERNATION)
|
|
bool kernel_page_present(struct page *page)
|
|
{
|
|
unsigned long addr;
|
|
int cc;
|
|
|
|
addr = page_to_phys(page);
|
|
asm volatile(
|
|
" lra %1,0(%1)\n"
|
|
" ipm %0\n"
|
|
" srl %0,28"
|
|
: "=d" (cc), "+a" (addr) : : "cc");
|
|
return cc == 0;
|
|
}
|
|
#endif /* CONFIG_HIBERNATION && CONFIG_DEBUG_PAGEALLOC */
|