2016-03-08 10:49:57 +00:00
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/*
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* KVM guest address space mapping code
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*
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* Copyright IBM Corp. 2007, 2016
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* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
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*/
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#include <linux/kernel.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/spinlock.h>
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#include <linux/slab.h>
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#include <linux/swapops.h>
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#include <linux/ksm.h>
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#include <linux/mman.h>
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#include <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <asm/gmap.h>
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#include <asm/tlb.h>
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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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2016-04-04 07:41:32 +00:00
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* @limit: maximum address of the gmap address space
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2016-03-08 10:49:57 +00:00
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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, unsigned long limit)
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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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unsigned long etype, atype;
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if (limit < (1UL << 31)) {
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limit = (1UL << 31) - 1;
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atype = _ASCE_TYPE_SEGMENT;
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etype = _SEGMENT_ENTRY_EMPTY;
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} else if (limit < (1UL << 42)) {
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limit = (1UL << 42) - 1;
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atype = _ASCE_TYPE_REGION3;
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etype = _REGION3_ENTRY_EMPTY;
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} else if (limit < (1UL << 53)) {
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limit = (1UL << 53) - 1;
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atype = _ASCE_TYPE_REGION2;
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etype = _REGION2_ENTRY_EMPTY;
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} else {
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limit = -1UL;
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atype = _ASCE_TYPE_REGION1;
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etype = _REGION1_ENTRY_EMPTY;
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}
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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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INIT_RADIX_TREE(&gmap->guest_to_host, GFP_KERNEL);
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INIT_RADIX_TREE(&gmap->host_to_guest, GFP_ATOMIC);
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spin_lock_init(&gmap->guest_table_lock);
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gmap->mm = mm;
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page = alloc_pages(GFP_KERNEL, 2);
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if (!page)
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goto out_free;
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page->index = 0;
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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, etype);
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gmap->table = table;
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gmap->asce = atype | _ASCE_TABLE_LENGTH |
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_ASCE_USER_BITS | __pa(table);
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gmap->asce_end = limit;
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2016-03-08 10:54:14 +00:00
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spin_lock(&mm->context.gmap_lock);
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list_add_rcu(&gmap->list, &mm->context.gmap_list);
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spin_unlock(&mm->context.gmap_lock);
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2016-03-08 10:49:57 +00:00
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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 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_asce(gmap->mm, gmap->asce);
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else
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__tlb_flush_global();
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}
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static void gmap_radix_tree_free(struct radix_tree_root *root)
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{
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struct radix_tree_iter iter;
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unsigned long indices[16];
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unsigned long index;
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void **slot;
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int i, nr;
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/* A radix tree is freed by deleting all of its entries */
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index = 0;
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do {
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nr = 0;
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radix_tree_for_each_slot(slot, root, &iter, index) {
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indices[nr] = iter.index;
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if (++nr == 16)
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break;
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}
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for (i = 0; i < nr; i++) {
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index = indices[i];
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radix_tree_delete(root, index);
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}
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} while (nr > 0);
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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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/* Flush tlb. */
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if (MACHINE_HAS_IDTE)
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__tlb_flush_asce(gmap->mm, gmap->asce);
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else
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__tlb_flush_global();
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2016-03-08 10:54:14 +00:00
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spin_lock(&gmap->mm->context.gmap_lock);
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list_del_rcu(&gmap->list);
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spin_unlock(&gmap->mm->context.gmap_lock);
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synchronize_rcu();
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2016-03-08 10:49:57 +00:00
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/* Free all segment & region tables. */
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list_for_each_entry_safe(page, next, &gmap->crst_list, lru)
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__free_pages(page, 2);
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gmap_radix_tree_free(&gmap->guest_to_host);
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gmap_radix_tree_free(&gmap->host_to_guest);
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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, unsigned long *table,
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unsigned long init, unsigned long gaddr)
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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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page = alloc_pages(GFP_KERNEL, 2);
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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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spin_lock(&gmap->mm->page_table_lock);
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if (*table & _REGION_ENTRY_INVALID) {
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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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page->index = gaddr;
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page = NULL;
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}
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spin_unlock(&gmap->mm->page_table_lock);
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if (page)
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__free_pages(page, 2);
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return 0;
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}
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/**
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* __gmap_segment_gaddr - find virtual address from segment pointer
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* @entry: pointer to a segment table entry in the guest address space
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*
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* Returns the virtual address in the guest address space for the segment
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*/
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static unsigned long __gmap_segment_gaddr(unsigned long *entry)
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{
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struct page *page;
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unsigned long offset, mask;
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offset = (unsigned long) entry / sizeof(unsigned long);
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offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE;
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mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
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page = virt_to_page((void *)((unsigned long) entry & mask));
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return page->index + offset;
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}
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/**
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* __gmap_unlink_by_vmaddr - unlink a single segment via a host address
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* @gmap: pointer to the guest address space structure
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* @vmaddr: address in the host process address space
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*
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* Returns 1 if a TLB flush is required
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*/
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static int __gmap_unlink_by_vmaddr(struct gmap *gmap, unsigned long vmaddr)
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{
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unsigned long *entry;
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int flush = 0;
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spin_lock(&gmap->guest_table_lock);
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entry = radix_tree_delete(&gmap->host_to_guest, vmaddr >> PMD_SHIFT);
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if (entry) {
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flush = (*entry != _SEGMENT_ENTRY_INVALID);
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*entry = _SEGMENT_ENTRY_INVALID;
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}
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spin_unlock(&gmap->guest_table_lock);
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return flush;
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}
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/**
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* __gmap_unmap_by_gaddr - unmap a single segment via a guest address
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* @gmap: pointer to the guest address space structure
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* @gaddr: address in the guest address space
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*
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* Returns 1 if a TLB flush is required
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*/
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static int __gmap_unmap_by_gaddr(struct gmap *gmap, unsigned long gaddr)
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{
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unsigned long vmaddr;
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vmaddr = (unsigned long) radix_tree_delete(&gmap->guest_to_host,
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gaddr >> PMD_SHIFT);
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return vmaddr ? __gmap_unlink_by_vmaddr(gmap, vmaddr) : 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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* @to: 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 succeeded, -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 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_write(&gmap->mm->mmap_sem);
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for (off = 0; off < len; off += PMD_SIZE)
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flush |= __gmap_unmap_by_gaddr(gmap, to + off);
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up_write(&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_map_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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* @len: length of the memory area to map
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*
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* Returns 0 if the mmap succeeded, -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 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 < from || to + len < to ||
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2016-04-04 07:41:32 +00:00
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from + len - 1 > TASK_MAX_SIZE || to + len - 1 > gmap->asce_end)
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2016-03-08 10:49:57 +00:00
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return -EINVAL;
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flush = 0;
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down_write(&gmap->mm->mmap_sem);
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for (off = 0; off < len; off += PMD_SIZE) {
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/* Remove old translation */
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flush |= __gmap_unmap_by_gaddr(gmap, to + off);
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/* Store new translation */
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if (radix_tree_insert(&gmap->guest_to_host,
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(to + off) >> PMD_SHIFT,
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(void *) from + off))
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break;
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}
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up_write(&gmap->mm->mmap_sem);
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if (flush)
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gmap_flush_tlb(gmap);
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if (off >= len)
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return 0;
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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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* __gmap_translate - translate a guest address to a user space address
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* @gmap: pointer to guest mapping meta data structure
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* @gaddr: guest address
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*
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* Returns user space address which corresponds to the guest address or
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* -EFAULT if no such mapping exists.
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* This function does not establish potentially missing page table entries.
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* The mmap_sem of the mm that belongs to the address space must be held
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* when this function gets called.
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*/
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unsigned long __gmap_translate(struct gmap *gmap, unsigned long gaddr)
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{
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unsigned long vmaddr;
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vmaddr = (unsigned long)
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radix_tree_lookup(&gmap->guest_to_host, gaddr >> PMD_SHIFT);
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return vmaddr ? (vmaddr | (gaddr & ~PMD_MASK)) : -EFAULT;
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}
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EXPORT_SYMBOL_GPL(__gmap_translate);
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/**
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* gmap_translate - translate a guest address to a user space address
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* @gmap: pointer to guest mapping meta data structure
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* @gaddr: guest address
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*
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* Returns user space address which corresponds to the guest address or
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* -EFAULT if no such mapping exists.
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* This function does not establish potentially missing page table entries.
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*/
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unsigned long gmap_translate(struct gmap *gmap, unsigned long gaddr)
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{
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unsigned long rc;
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down_read(&gmap->mm->mmap_sem);
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rc = __gmap_translate(gmap, gaddr);
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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_translate);
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/**
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|
|
* gmap_unlink - disconnect a page table from the gmap shadow tables
|
|
|
|
* @gmap: pointer to guest mapping meta data structure
|
|
|
|
* @table: pointer to the host page table
|
|
|
|
* @vmaddr: vm address associated with the host page table
|
|
|
|
*/
|
|
|
|
void gmap_unlink(struct mm_struct *mm, unsigned long *table,
|
|
|
|
unsigned long vmaddr)
|
|
|
|
{
|
|
|
|
struct gmap *gmap;
|
|
|
|
int flush;
|
|
|
|
|
2016-03-08 10:54:14 +00:00
|
|
|
rcu_read_lock();
|
|
|
|
list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
|
2016-03-08 10:49:57 +00:00
|
|
|
flush = __gmap_unlink_by_vmaddr(gmap, vmaddr);
|
|
|
|
if (flush)
|
|
|
|
gmap_flush_tlb(gmap);
|
|
|
|
}
|
2016-03-08 10:54:14 +00:00
|
|
|
rcu_read_unlock();
|
2016-03-08 10:49:57 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* gmap_link - set up shadow page tables to connect a host to a guest address
|
|
|
|
* @gmap: pointer to guest mapping meta data structure
|
|
|
|
* @gaddr: guest address
|
|
|
|
* @vmaddr: vm address
|
|
|
|
*
|
|
|
|
* Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
|
|
|
|
* if the vm address is already mapped to a different guest segment.
|
|
|
|
* The mmap_sem of the mm that belongs to the address space must be held
|
|
|
|
* when this function gets called.
|
|
|
|
*/
|
|
|
|
int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr)
|
|
|
|
{
|
|
|
|
struct mm_struct *mm;
|
|
|
|
unsigned long *table;
|
|
|
|
spinlock_t *ptl;
|
|
|
|
pgd_t *pgd;
|
|
|
|
pud_t *pud;
|
|
|
|
pmd_t *pmd;
|
|
|
|
int rc;
|
|
|
|
|
|
|
|
/* Create higher level tables in the gmap page table */
|
|
|
|
table = gmap->table;
|
|
|
|
if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION1) {
|
|
|
|
table += (gaddr >> 53) & 0x7ff;
|
|
|
|
if ((*table & _REGION_ENTRY_INVALID) &&
|
|
|
|
gmap_alloc_table(gmap, table, _REGION2_ENTRY_EMPTY,
|
|
|
|
gaddr & 0xffe0000000000000UL))
|
|
|
|
return -ENOMEM;
|
|
|
|
table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
|
|
|
|
}
|
|
|
|
if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION2) {
|
|
|
|
table += (gaddr >> 42) & 0x7ff;
|
|
|
|
if ((*table & _REGION_ENTRY_INVALID) &&
|
|
|
|
gmap_alloc_table(gmap, table, _REGION3_ENTRY_EMPTY,
|
|
|
|
gaddr & 0xfffffc0000000000UL))
|
|
|
|
return -ENOMEM;
|
|
|
|
table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
|
|
|
|
}
|
|
|
|
if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION3) {
|
|
|
|
table += (gaddr >> 31) & 0x7ff;
|
|
|
|
if ((*table & _REGION_ENTRY_INVALID) &&
|
|
|
|
gmap_alloc_table(gmap, table, _SEGMENT_ENTRY_EMPTY,
|
|
|
|
gaddr & 0xffffffff80000000UL))
|
|
|
|
return -ENOMEM;
|
|
|
|
table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
|
|
|
|
}
|
|
|
|
table += (gaddr >> 20) & 0x7ff;
|
|
|
|
/* Walk the parent mm page table */
|
|
|
|
mm = gmap->mm;
|
|
|
|
pgd = pgd_offset(mm, vmaddr);
|
|
|
|
VM_BUG_ON(pgd_none(*pgd));
|
|
|
|
pud = pud_offset(pgd, vmaddr);
|
|
|
|
VM_BUG_ON(pud_none(*pud));
|
|
|
|
pmd = pmd_offset(pud, vmaddr);
|
|
|
|
VM_BUG_ON(pmd_none(*pmd));
|
|
|
|
/* large pmds cannot yet be handled */
|
|
|
|
if (pmd_large(*pmd))
|
|
|
|
return -EFAULT;
|
|
|
|
/* Link gmap segment table entry location to page table. */
|
|
|
|
rc = radix_tree_preload(GFP_KERNEL);
|
|
|
|
if (rc)
|
|
|
|
return rc;
|
|
|
|
ptl = pmd_lock(mm, pmd);
|
|
|
|
spin_lock(&gmap->guest_table_lock);
|
|
|
|
if (*table == _SEGMENT_ENTRY_INVALID) {
|
|
|
|
rc = radix_tree_insert(&gmap->host_to_guest,
|
|
|
|
vmaddr >> PMD_SHIFT, table);
|
|
|
|
if (!rc)
|
|
|
|
*table = pmd_val(*pmd);
|
|
|
|
} else
|
|
|
|
rc = 0;
|
|
|
|
spin_unlock(&gmap->guest_table_lock);
|
|
|
|
spin_unlock(ptl);
|
|
|
|
radix_tree_preload_end();
|
|
|
|
return rc;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* gmap_fault - resolve a fault on a guest address
|
|
|
|
* @gmap: pointer to guest mapping meta data structure
|
|
|
|
* @gaddr: guest address
|
|
|
|
* @fault_flags: flags to pass down to handle_mm_fault()
|
|
|
|
*
|
|
|
|
* Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
|
|
|
|
* if the vm address is already mapped to a different guest segment.
|
|
|
|
*/
|
|
|
|
int gmap_fault(struct gmap *gmap, unsigned long gaddr,
|
|
|
|
unsigned int fault_flags)
|
|
|
|
{
|
|
|
|
unsigned long vmaddr;
|
|
|
|
int rc;
|
|
|
|
bool unlocked;
|
|
|
|
|
|
|
|
down_read(&gmap->mm->mmap_sem);
|
|
|
|
|
|
|
|
retry:
|
|
|
|
unlocked = false;
|
|
|
|
vmaddr = __gmap_translate(gmap, gaddr);
|
|
|
|
if (IS_ERR_VALUE(vmaddr)) {
|
|
|
|
rc = vmaddr;
|
|
|
|
goto out_up;
|
|
|
|
}
|
|
|
|
if (fixup_user_fault(current, gmap->mm, vmaddr, fault_flags,
|
|
|
|
&unlocked)) {
|
|
|
|
rc = -EFAULT;
|
|
|
|
goto out_up;
|
|
|
|
}
|
|
|
|
/*
|
|
|
|
* In the case that fixup_user_fault unlocked the mmap_sem during
|
|
|
|
* faultin redo __gmap_translate to not race with a map/unmap_segment.
|
|
|
|
*/
|
|
|
|
if (unlocked)
|
|
|
|
goto retry;
|
|
|
|
|
|
|
|
rc = __gmap_link(gmap, gaddr, vmaddr);
|
|
|
|
out_up:
|
|
|
|
up_read(&gmap->mm->mmap_sem);
|
|
|
|
return rc;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(gmap_fault);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* this function is assumed to be called with mmap_sem held
|
|
|
|
*/
|
|
|
|
void __gmap_zap(struct gmap *gmap, unsigned long gaddr)
|
|
|
|
{
|
|
|
|
unsigned long vmaddr;
|
|
|
|
spinlock_t *ptl;
|
|
|
|
pte_t *ptep;
|
|
|
|
|
|
|
|
/* Find the vm address for the guest address */
|
|
|
|
vmaddr = (unsigned long) radix_tree_lookup(&gmap->guest_to_host,
|
|
|
|
gaddr >> PMD_SHIFT);
|
|
|
|
if (vmaddr) {
|
|
|
|
vmaddr |= gaddr & ~PMD_MASK;
|
|
|
|
/* Get pointer to the page table entry */
|
|
|
|
ptep = get_locked_pte(gmap->mm, vmaddr, &ptl);
|
|
|
|
if (likely(ptep))
|
|
|
|
ptep_zap_unused(gmap->mm, vmaddr, ptep, 0);
|
|
|
|
pte_unmap_unlock(ptep, ptl);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(__gmap_zap);
|
|
|
|
|
|
|
|
void gmap_discard(struct gmap *gmap, unsigned long from, unsigned long to)
|
|
|
|
{
|
|
|
|
unsigned long gaddr, vmaddr, size;
|
|
|
|
struct vm_area_struct *vma;
|
|
|
|
|
|
|
|
down_read(&gmap->mm->mmap_sem);
|
|
|
|
for (gaddr = from; gaddr < to;
|
|
|
|
gaddr = (gaddr + PMD_SIZE) & PMD_MASK) {
|
|
|
|
/* Find the vm address for the guest address */
|
|
|
|
vmaddr = (unsigned long)
|
|
|
|
radix_tree_lookup(&gmap->guest_to_host,
|
|
|
|
gaddr >> PMD_SHIFT);
|
|
|
|
if (!vmaddr)
|
|
|
|
continue;
|
|
|
|
vmaddr |= gaddr & ~PMD_MASK;
|
|
|
|
/* Find vma in the parent mm */
|
|
|
|
vma = find_vma(gmap->mm, vmaddr);
|
|
|
|
size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK));
|
|
|
|
zap_page_range(vma, vmaddr, size, NULL);
|
|
|
|
}
|
|
|
|
up_read(&gmap->mm->mmap_sem);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(gmap_discard);
|
|
|
|
|
|
|
|
static LIST_HEAD(gmap_notifier_list);
|
|
|
|
static DEFINE_SPINLOCK(gmap_notifier_lock);
|
|
|
|
|
|
|
|
/**
|
2016-03-08 10:54:42 +00:00
|
|
|
* gmap_register_pte_notifier - register a pte invalidation callback
|
2016-03-08 10:49:57 +00:00
|
|
|
* @nb: pointer to the gmap notifier block
|
|
|
|
*/
|
2016-03-08 10:54:42 +00:00
|
|
|
void gmap_register_pte_notifier(struct gmap_notifier *nb)
|
2016-03-08 10:49:57 +00:00
|
|
|
{
|
|
|
|
spin_lock(&gmap_notifier_lock);
|
2016-03-08 10:54:14 +00:00
|
|
|
list_add_rcu(&nb->list, &gmap_notifier_list);
|
2016-03-08 10:49:57 +00:00
|
|
|
spin_unlock(&gmap_notifier_lock);
|
|
|
|
}
|
2016-03-08 10:54:42 +00:00
|
|
|
EXPORT_SYMBOL_GPL(gmap_register_pte_notifier);
|
2016-03-08 10:49:57 +00:00
|
|
|
|
|
|
|
/**
|
2016-03-08 10:54:42 +00:00
|
|
|
* gmap_unregister_pte_notifier - remove a pte invalidation callback
|
2016-03-08 10:49:57 +00:00
|
|
|
* @nb: pointer to the gmap notifier block
|
|
|
|
*/
|
2016-03-08 10:54:42 +00:00
|
|
|
void gmap_unregister_pte_notifier(struct gmap_notifier *nb)
|
2016-03-08 10:49:57 +00:00
|
|
|
{
|
|
|
|
spin_lock(&gmap_notifier_lock);
|
2016-03-08 10:54:14 +00:00
|
|
|
list_del_rcu(&nb->list);
|
2016-03-08 10:49:57 +00:00
|
|
|
spin_unlock(&gmap_notifier_lock);
|
2016-03-08 10:54:14 +00:00
|
|
|
synchronize_rcu();
|
2016-03-08 10:49:57 +00:00
|
|
|
}
|
2016-03-08 10:54:42 +00:00
|
|
|
EXPORT_SYMBOL_GPL(gmap_unregister_pte_notifier);
|
2016-03-08 10:49:57 +00:00
|
|
|
|
2016-03-08 10:52:54 +00:00
|
|
|
/**
|
|
|
|
* gmap_call_notifier - call all registered invalidation callbacks
|
|
|
|
* @gmap: pointer to guest mapping meta data structure
|
|
|
|
* @start: start virtual address in the guest address space
|
|
|
|
* @end: end virtual address in the guest address space
|
|
|
|
*/
|
|
|
|
static void gmap_call_notifier(struct gmap *gmap, unsigned long start,
|
|
|
|
unsigned long end)
|
|
|
|
{
|
|
|
|
struct gmap_notifier *nb;
|
|
|
|
|
|
|
|
list_for_each_entry(nb, &gmap_notifier_list, list)
|
|
|
|
nb->notifier_call(gmap, start, end);
|
|
|
|
}
|
|
|
|
|
2016-03-08 10:49:57 +00:00
|
|
|
/**
|
2016-03-08 10:54:42 +00:00
|
|
|
* gmap_table_walk - walk the gmap page tables
|
|
|
|
* @gmap: pointer to guest mapping meta data structure
|
|
|
|
* @gaddr: virtual address in the guest address space
|
|
|
|
*
|
|
|
|
* Returns a table pointer for the given guest address.
|
|
|
|
*/
|
|
|
|
static inline unsigned long *gmap_table_walk(struct gmap *gmap,
|
|
|
|
unsigned long gaddr)
|
|
|
|
{
|
|
|
|
unsigned long *table;
|
|
|
|
|
|
|
|
table = gmap->table;
|
|
|
|
switch (gmap->asce & _ASCE_TYPE_MASK) {
|
|
|
|
case _ASCE_TYPE_REGION1:
|
|
|
|
table += (gaddr >> 53) & 0x7ff;
|
|
|
|
if (*table & _REGION_ENTRY_INVALID)
|
|
|
|
return NULL;
|
|
|
|
table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
|
|
|
|
/* Fallthrough */
|
|
|
|
case _ASCE_TYPE_REGION2:
|
|
|
|
table += (gaddr >> 42) & 0x7ff;
|
|
|
|
if (*table & _REGION_ENTRY_INVALID)
|
|
|
|
return NULL;
|
|
|
|
table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
|
|
|
|
/* Fallthrough */
|
|
|
|
case _ASCE_TYPE_REGION3:
|
|
|
|
table += (gaddr >> 31) & 0x7ff;
|
|
|
|
if (*table & _REGION_ENTRY_INVALID)
|
|
|
|
return NULL;
|
|
|
|
table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
|
|
|
|
/* Fallthrough */
|
|
|
|
case _ASCE_TYPE_SEGMENT:
|
|
|
|
table += (gaddr >> 20) & 0x7ff;
|
|
|
|
}
|
|
|
|
return table;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* gmap_pte_op_walk - walk the gmap page table, get the page table lock
|
|
|
|
* and return the pte pointer
|
|
|
|
* @gmap: pointer to guest mapping meta data structure
|
|
|
|
* @gaddr: virtual address in the guest address space
|
|
|
|
* @ptl: pointer to the spinlock pointer
|
|
|
|
*
|
|
|
|
* Returns a pointer to the locked pte for a guest address, or NULL
|
|
|
|
*/
|
|
|
|
static pte_t *gmap_pte_op_walk(struct gmap *gmap, unsigned long gaddr,
|
|
|
|
spinlock_t **ptl)
|
|
|
|
{
|
|
|
|
unsigned long *table;
|
|
|
|
|
|
|
|
/* Walk the gmap page table, lock and get pte pointer */
|
|
|
|
table = gmap_table_walk(gmap, gaddr);
|
|
|
|
if (!table || *table & _SEGMENT_ENTRY_INVALID)
|
|
|
|
return NULL;
|
|
|
|
return pte_alloc_map_lock(gmap->mm, (pmd_t *) table, gaddr, ptl);
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* gmap_pte_op_fixup - force a page in and connect the gmap page table
|
|
|
|
* @gmap: pointer to guest mapping meta data structure
|
|
|
|
* @gaddr: virtual address in the guest address space
|
|
|
|
* @vmaddr: address in the host process address space
|
|
|
|
*
|
|
|
|
* Returns 0 if the caller can retry __gmap_translate (might fail again),
|
|
|
|
* -ENOMEM if out of memory and -EFAULT if anything goes wrong while fixing
|
|
|
|
* up or connecting the gmap page table.
|
|
|
|
*/
|
|
|
|
static int gmap_pte_op_fixup(struct gmap *gmap, unsigned long gaddr,
|
|
|
|
unsigned long vmaddr)
|
|
|
|
{
|
|
|
|
struct mm_struct *mm = gmap->mm;
|
|
|
|
bool unlocked = false;
|
|
|
|
|
|
|
|
if (fixup_user_fault(current, mm, vmaddr, FAULT_FLAG_WRITE, &unlocked))
|
|
|
|
return -EFAULT;
|
|
|
|
if (unlocked)
|
|
|
|
/* lost mmap_sem, caller has to retry __gmap_translate */
|
|
|
|
return 0;
|
|
|
|
/* Connect the page tables */
|
|
|
|
return __gmap_link(gmap, gaddr, vmaddr);
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* gmap_pte_op_end - release the page table lock
|
|
|
|
* @ptl: pointer to the spinlock pointer
|
|
|
|
*/
|
|
|
|
static void gmap_pte_op_end(spinlock_t *ptl)
|
|
|
|
{
|
|
|
|
spin_unlock(ptl);
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* gmap_mprotect_notify - change access rights for a range of ptes and
|
|
|
|
* call the notifier if any pte changes again
|
2016-03-08 10:49:57 +00:00
|
|
|
* @gmap: pointer to guest mapping meta data structure
|
|
|
|
* @gaddr: virtual address in the guest address space
|
|
|
|
* @len: size of area
|
2016-03-08 10:54:42 +00:00
|
|
|
* @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
|
2016-03-08 10:49:57 +00:00
|
|
|
*
|
2016-03-08 10:54:42 +00:00
|
|
|
* Returns 0 if for each page in the given range a gmap mapping exists,
|
|
|
|
* the new access rights could be set and the notifier could be armed.
|
|
|
|
* If the gmap mapping is missing for one or more pages -EFAULT is
|
|
|
|
* returned. If no memory could be allocated -ENOMEM is returned.
|
|
|
|
* This function establishes missing page table entries.
|
2016-03-08 10:49:57 +00:00
|
|
|
*/
|
2016-03-08 10:54:42 +00:00
|
|
|
int gmap_mprotect_notify(struct gmap *gmap, unsigned long gaddr,
|
|
|
|
unsigned long len, int prot)
|
2016-03-08 10:49:57 +00:00
|
|
|
{
|
2016-03-08 10:54:42 +00:00
|
|
|
unsigned long vmaddr;
|
2016-03-08 10:49:57 +00:00
|
|
|
spinlock_t *ptl;
|
|
|
|
pte_t *ptep;
|
|
|
|
int rc = 0;
|
|
|
|
|
|
|
|
if ((gaddr & ~PAGE_MASK) || (len & ~PAGE_MASK))
|
|
|
|
return -EINVAL;
|
2016-03-08 10:54:42 +00:00
|
|
|
if (!MACHINE_HAS_ESOP && prot == PROT_READ)
|
|
|
|
return -EINVAL;
|
2016-03-08 10:49:57 +00:00
|
|
|
down_read(&gmap->mm->mmap_sem);
|
|
|
|
while (len) {
|
2016-03-08 10:54:42 +00:00
|
|
|
rc = -EAGAIN;
|
|
|
|
ptep = gmap_pte_op_walk(gmap, gaddr, &ptl);
|
|
|
|
if (ptep) {
|
|
|
|
rc = ptep_force_prot(gmap->mm, gaddr, ptep, prot);
|
|
|
|
gmap_pte_op_end(ptl);
|
2016-03-08 10:49:57 +00:00
|
|
|
}
|
2016-03-08 10:54:42 +00:00
|
|
|
if (rc) {
|
|
|
|
vmaddr = __gmap_translate(gmap, gaddr);
|
|
|
|
if (IS_ERR_VALUE(vmaddr)) {
|
|
|
|
rc = vmaddr;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
rc = gmap_pte_op_fixup(gmap, gaddr, vmaddr);
|
|
|
|
if (rc)
|
|
|
|
break;
|
2016-03-08 10:49:57 +00:00
|
|
|
continue;
|
|
|
|
}
|
2016-03-08 10:54:42 +00:00
|
|
|
gaddr += PAGE_SIZE;
|
|
|
|
len -= PAGE_SIZE;
|
2016-03-08 10:49:57 +00:00
|
|
|
}
|
|
|
|
up_read(&gmap->mm->mmap_sem);
|
|
|
|
return rc;
|
|
|
|
}
|
2016-03-08 10:54:42 +00:00
|
|
|
EXPORT_SYMBOL_GPL(gmap_mprotect_notify);
|
2016-03-08 10:49:57 +00:00
|
|
|
|
|
|
|
/**
|
|
|
|
* ptep_notify - call all invalidation callbacks for a specific pte.
|
|
|
|
* @mm: pointer to the process mm_struct
|
|
|
|
* @addr: virtual address in the process address space
|
|
|
|
* @pte: pointer to the page table entry
|
|
|
|
*
|
|
|
|
* This function is assumed to be called with the page table lock held
|
|
|
|
* for the pte to notify.
|
|
|
|
*/
|
|
|
|
void ptep_notify(struct mm_struct *mm, unsigned long vmaddr, pte_t *pte)
|
|
|
|
{
|
|
|
|
unsigned long offset, gaddr;
|
|
|
|
unsigned long *table;
|
|
|
|
struct gmap *gmap;
|
|
|
|
|
|
|
|
offset = ((unsigned long) pte) & (255 * sizeof(pte_t));
|
|
|
|
offset = offset * (4096 / sizeof(pte_t));
|
2016-03-08 10:54:14 +00:00
|
|
|
rcu_read_lock();
|
|
|
|
list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
|
|
|
|
spin_lock(&gmap->guest_table_lock);
|
2016-03-08 10:49:57 +00:00
|
|
|
table = radix_tree_lookup(&gmap->host_to_guest,
|
|
|
|
vmaddr >> PMD_SHIFT);
|
2016-03-08 10:54:14 +00:00
|
|
|
if (table)
|
|
|
|
gaddr = __gmap_segment_gaddr(table) + offset;
|
|
|
|
spin_unlock(&gmap->guest_table_lock);
|
|
|
|
if (table)
|
|
|
|
gmap_call_notifier(gmap, gaddr, gaddr + PAGE_SIZE - 1);
|
2016-03-08 10:49:57 +00:00
|
|
|
}
|
2016-03-08 10:54:14 +00:00
|
|
|
rcu_read_unlock();
|
2016-03-08 10:49:57 +00:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(ptep_notify);
|
|
|
|
|
|
|
|
static inline void thp_split_mm(struct mm_struct *mm)
|
|
|
|
{
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
|
|
struct vm_area_struct *vma;
|
|
|
|
unsigned long addr;
|
|
|
|
|
|
|
|
for (vma = mm->mmap; vma != NULL; vma = vma->vm_next) {
|
|
|
|
for (addr = vma->vm_start;
|
|
|
|
addr < vma->vm_end;
|
|
|
|
addr += PAGE_SIZE)
|
|
|
|
follow_page(vma, addr, FOLL_SPLIT);
|
|
|
|
vma->vm_flags &= ~VM_HUGEPAGE;
|
|
|
|
vma->vm_flags |= VM_NOHUGEPAGE;
|
|
|
|
}
|
|
|
|
mm->def_flags |= VM_NOHUGEPAGE;
|
|
|
|
#endif
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* switch on pgstes for its userspace process (for kvm)
|
|
|
|
*/
|
|
|
|
int s390_enable_sie(void)
|
|
|
|
{
|
|
|
|
struct mm_struct *mm = current->mm;
|
|
|
|
|
|
|
|
/* Do we have pgstes? if yes, we are done */
|
|
|
|
if (mm_has_pgste(mm))
|
|
|
|
return 0;
|
|
|
|
/* Fail if the page tables are 2K */
|
|
|
|
if (!mm_alloc_pgste(mm))
|
|
|
|
return -EINVAL;
|
|
|
|
down_write(&mm->mmap_sem);
|
|
|
|
mm->context.has_pgste = 1;
|
|
|
|
/* split thp mappings and disable thp for future mappings */
|
|
|
|
thp_split_mm(mm);
|
|
|
|
up_write(&mm->mmap_sem);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(s390_enable_sie);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Enable storage key handling from now on and initialize the storage
|
|
|
|
* keys with the default key.
|
|
|
|
*/
|
|
|
|
static int __s390_enable_skey(pte_t *pte, unsigned long addr,
|
|
|
|
unsigned long next, struct mm_walk *walk)
|
|
|
|
{
|
|
|
|
/*
|
|
|
|
* Remove all zero page mappings,
|
|
|
|
* after establishing a policy to forbid zero page mappings
|
|
|
|
* following faults for that page will get fresh anonymous pages
|
|
|
|
*/
|
|
|
|
if (is_zero_pfn(pte_pfn(*pte)))
|
|
|
|
ptep_xchg_direct(walk->mm, addr, pte, __pte(_PAGE_INVALID));
|
|
|
|
/* Clear storage key */
|
|
|
|
ptep_zap_key(walk->mm, addr, pte);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
int s390_enable_skey(void)
|
|
|
|
{
|
|
|
|
struct mm_walk walk = { .pte_entry = __s390_enable_skey };
|
|
|
|
struct mm_struct *mm = current->mm;
|
|
|
|
struct vm_area_struct *vma;
|
|
|
|
int rc = 0;
|
|
|
|
|
|
|
|
down_write(&mm->mmap_sem);
|
|
|
|
if (mm_use_skey(mm))
|
|
|
|
goto out_up;
|
|
|
|
|
|
|
|
mm->context.use_skey = 1;
|
|
|
|
for (vma = mm->mmap; vma; vma = vma->vm_next) {
|
|
|
|
if (ksm_madvise(vma, vma->vm_start, vma->vm_end,
|
|
|
|
MADV_UNMERGEABLE, &vma->vm_flags)) {
|
|
|
|
mm->context.use_skey = 0;
|
|
|
|
rc = -ENOMEM;
|
|
|
|
goto out_up;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
mm->def_flags &= ~VM_MERGEABLE;
|
|
|
|
|
|
|
|
walk.mm = mm;
|
|
|
|
walk_page_range(0, TASK_SIZE, &walk);
|
|
|
|
|
|
|
|
out_up:
|
|
|
|
up_write(&mm->mmap_sem);
|
|
|
|
return rc;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(s390_enable_skey);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Reset CMMA state, make all pages stable again.
|
|
|
|
*/
|
|
|
|
static int __s390_reset_cmma(pte_t *pte, unsigned long addr,
|
|
|
|
unsigned long next, struct mm_walk *walk)
|
|
|
|
{
|
|
|
|
ptep_zap_unused(walk->mm, addr, pte, 1);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
void s390_reset_cmma(struct mm_struct *mm)
|
|
|
|
{
|
|
|
|
struct mm_walk walk = { .pte_entry = __s390_reset_cmma };
|
|
|
|
|
|
|
|
down_write(&mm->mmap_sem);
|
|
|
|
walk.mm = mm;
|
|
|
|
walk_page_range(0, TASK_SIZE, &walk);
|
|
|
|
up_write(&mm->mmap_sem);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(s390_reset_cmma);
|