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Diffstat (limited to 'arch/s390/mm/pgtable.c')
-rw-r--r--arch/s390/mm/pgtable.c158
1 files changed, 153 insertions, 5 deletions
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 3584ed9b20a1..796c9320c709 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -17,6 +17,7 @@
#include <linux/quicklist.h>
#include <linux/rcupdate.h>
#include <linux/slab.h>
+#include <linux/swapops.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
@@ -594,6 +595,82 @@ unsigned long gmap_fault(unsigned long address, struct gmap *gmap)
}
EXPORT_SYMBOL_GPL(gmap_fault);
+static void gmap_zap_swap_entry(swp_entry_t entry, struct mm_struct *mm)
+{
+ if (!non_swap_entry(entry))
+ dec_mm_counter(mm, MM_SWAPENTS);
+ else if (is_migration_entry(entry)) {
+ struct page *page = migration_entry_to_page(entry);
+
+ if (PageAnon(page))
+ dec_mm_counter(mm, MM_ANONPAGES);
+ else
+ dec_mm_counter(mm, MM_FILEPAGES);
+ }
+ free_swap_and_cache(entry);
+}
+
+/**
+ * The mm->mmap_sem lock must be held
+ */
+static void gmap_zap_unused(struct mm_struct *mm, unsigned long address)
+{
+ unsigned long ptev, pgstev;
+ spinlock_t *ptl;
+ pgste_t pgste;
+ pte_t *ptep, pte;
+
+ ptep = get_locked_pte(mm, address, &ptl);
+ if (unlikely(!ptep))
+ return;
+ pte = *ptep;
+ if (!pte_swap(pte))
+ goto out_pte;
+ /* Zap unused and logically-zero pages */
+ pgste = pgste_get_lock(ptep);
+ pgstev = pgste_val(pgste);
+ ptev = pte_val(pte);
+ if (((pgstev & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED) ||
+ ((pgstev & _PGSTE_GPS_ZERO) && (ptev & _PAGE_INVALID))) {
+ gmap_zap_swap_entry(pte_to_swp_entry(pte), mm);
+ pte_clear(mm, address, ptep);
+ }
+ pgste_set_unlock(ptep, pgste);
+out_pte:
+ pte_unmap_unlock(*ptep, ptl);
+}
+
+/*
+ * this function is assumed to be called with mmap_sem held
+ */
+void __gmap_zap(unsigned long address, struct gmap *gmap)
+{
+ unsigned long *table, *segment_ptr;
+ unsigned long segment, pgstev, ptev;
+ struct gmap_pgtable *mp;
+ struct page *page;
+
+ segment_ptr = gmap_table_walk(address, gmap);
+ if (IS_ERR(segment_ptr))
+ return;
+ segment = *segment_ptr;
+ if (segment & _SEGMENT_ENTRY_INVALID)
+ return;
+ page = pfn_to_page(segment >> PAGE_SHIFT);
+ mp = (struct gmap_pgtable *) page->index;
+ address = mp->vmaddr | (address & ~PMD_MASK);
+ /* Page table is present */
+ table = (unsigned long *)(segment & _SEGMENT_ENTRY_ORIGIN);
+ table = table + ((address >> 12) & 0xff);
+ pgstev = table[PTRS_PER_PTE];
+ ptev = table[0];
+ /* quick check, checked again with locks held */
+ if (((pgstev & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED) ||
+ ((pgstev & _PGSTE_GPS_ZERO) && (ptev & _PAGE_INVALID)))
+ gmap_zap_unused(gmap->mm, address);
+}
+EXPORT_SYMBOL_GPL(__gmap_zap);
+
void gmap_discard(unsigned long from, unsigned long to, struct gmap *gmap)
{
@@ -671,7 +748,7 @@ EXPORT_SYMBOL_GPL(gmap_unregister_ipte_notifier);
/**
* gmap_ipte_notify - mark a range of ptes for invalidation notification
* @gmap: pointer to guest mapping meta data structure
- * @address: virtual address in the guest address space
+ * @start: virtual address in the guest address space
* @len: size of area
*
* Returns 0 if for each page in the given range a gmap mapping exists and
@@ -725,13 +802,12 @@ EXPORT_SYMBOL_GPL(gmap_ipte_notify);
/**
* gmap_do_ipte_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 gmap_do_ipte_notify(struct mm_struct *mm, unsigned long addr, pte_t *pte)
+void gmap_do_ipte_notify(struct mm_struct *mm, pte_t *pte)
{
unsigned long segment_offset;
struct gmap_notifier *nb;
@@ -802,6 +878,78 @@ static inline void page_table_free_pgste(unsigned long *table)
__free_page(page);
}
+static inline unsigned long page_table_reset_pte(struct mm_struct *mm,
+ pmd_t *pmd, unsigned long addr, unsigned long end)
+{
+ pte_t *start_pte, *pte;
+ spinlock_t *ptl;
+ pgste_t pgste;
+
+ start_pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
+ pte = start_pte;
+ do {
+ pgste = pgste_get_lock(pte);
+ pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;
+ pgste_set_unlock(pte, pgste);
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+ pte_unmap_unlock(start_pte, ptl);
+
+ return addr;
+}
+
+static inline unsigned long page_table_reset_pmd(struct mm_struct *mm,
+ pud_t *pud, unsigned long addr, unsigned long end)
+{
+ unsigned long next;
+ pmd_t *pmd;
+
+ pmd = pmd_offset(pud, addr);
+ do {
+ next = pmd_addr_end(addr, end);
+ if (pmd_none_or_clear_bad(pmd))
+ continue;
+ next = page_table_reset_pte(mm, pmd, addr, next);
+ } while (pmd++, addr = next, addr != end);
+
+ return addr;
+}
+
+static inline unsigned long page_table_reset_pud(struct mm_struct *mm,
+ pgd_t *pgd, unsigned long addr, unsigned long end)
+{
+ unsigned long next;
+ pud_t *pud;
+
+ pud = pud_offset(pgd, addr);
+ do {
+ next = pud_addr_end(addr, end);
+ if (pud_none_or_clear_bad(pud))
+ continue;
+ next = page_table_reset_pmd(mm, pud, addr, next);
+ } while (pud++, addr = next, addr != end);
+
+ return addr;
+}
+
+void page_table_reset_pgste(struct mm_struct *mm,
+ unsigned long start, unsigned long end)
+{
+ unsigned long addr, next;
+ pgd_t *pgd;
+
+ addr = start;
+ down_read(&mm->mmap_sem);
+ pgd = pgd_offset(mm, addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ if (pgd_none_or_clear_bad(pgd))
+ continue;
+ next = page_table_reset_pud(mm, pgd, addr, next);
+ } while (pgd++, addr = next, addr != end);
+ up_read(&mm->mmap_sem);
+}
+EXPORT_SYMBOL(page_table_reset_pgste);
+
int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
unsigned long key, bool nq)
{
@@ -1248,7 +1396,7 @@ void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
{
struct list_head *lh = (struct list_head *) pgtable;
- assert_spin_locked(&mm->page_table_lock);
+ assert_spin_locked(pmd_lockptr(mm, pmdp));
/* FIFO */
if (!pmd_huge_pte(mm, pmdp))
@@ -1264,7 +1412,7 @@ pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
pgtable_t pgtable;
pte_t *ptep;
- assert_spin_locked(&mm->page_table_lock);
+ assert_spin_locked(pmd_lockptr(mm, pmdp));
/* FIFO */
pgtable = pmd_huge_pte(mm, pmdp);