s390/mm: recfactor global pgste updates

Replace the s390 specific page table walker for the pgste updates
with a call to the common code walk_page_range function.
There are now two pte modification functions, one for the reset
of the CMMA state and another one for the initialization of the
storage keys.

Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h
index d39a31c3cdf2055ce794ffc287bcce6d6848cfa9..e510b9460efa40bd165d2a254fa283d1d72a20b3 100644 (file)
--- a/arch/s390/include/asm/pgalloc.h
+++ b/arch/s390/include/asm/pgalloc.h
@@ -22,8 +22,6 @@ unsigned long *page_table_alloc(struct mm_struct *);
 void page_table_free(struct mm_struct *, unsigned long *);
 void page_table_free_rcu(struct mmu_gather *, unsigned long *, unsigned long);
 
-void page_table_reset_pgste(struct mm_struct *, unsigned long, unsigned long,
-                           bool init_skey);
 int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
                          unsigned long key, bool nq);
 

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 57c882761deaa2e543342e5bb68cdb5524851eef..4399be1aaeff128e5d0965378c60fb02c96a0a96 100644 (file)
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1747,6 +1747,7 @@ extern int vmem_add_mapping(unsigned long start, unsigned long size);
 extern int vmem_remove_mapping(unsigned long start, unsigned long size);
 extern int s390_enable_sie(void);
 extern void s390_enable_skey(void);
+extern void s390_reset_cmma(struct mm_struct *mm);
 
 /*
  * No page table caches to initialise

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 55aade49b6d1164f1ecd01f14f5cdb841077df6d..6b049ee75a5694d74cce4f6402b92ae7879f8c4e 100644 (file)
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -271,7 +271,7 @@ static int kvm_s390_mem_control(struct kvm *kvm, struct kvm_device_attr *attr)
        case KVM_S390_VM_MEM_CLR_CMMA:
                mutex_lock(&kvm->lock);
                idx = srcu_read_lock(&kvm->srcu);
-               page_table_reset_pgste(kvm->arch.gmap->mm, 0, TASK_SIZE, false);
+               s390_reset_cmma(kvm->arch.gmap->mm);
                srcu_read_unlock(&kvm->srcu, idx);
                mutex_unlock(&kvm->lock);
                ret = 0;

diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 1b79ca67392fdffc2e6dd7328717267d16d87650..019afdf50b1a35393250993c689a8c5ce5e21c2e 100644 (file)
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -834,99 +834,6 @@ 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, bool init_skey)
-{
-       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;
-               if (init_skey) {
-                       unsigned long address;
-
-                       pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT |
-                                             PGSTE_GR_BIT | PGSTE_GC_BIT);
-
-                       /* skip invalid and not writable pages */
-                       if (pte_val(*pte) & _PAGE_INVALID ||
-                           !(pte_val(*pte) & _PAGE_WRITE)) {
-                               pgste_set_unlock(pte, pgste);
-                               continue;
-                       }
-
-                       address = pte_val(*pte) & PAGE_MASK;
-                       page_set_storage_key(address, PAGE_DEFAULT_KEY, 1);
-               }
-               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, bool init_skey)
-{
-       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, init_skey);
-       } 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, bool init_skey)
-{
-       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, init_skey);
-       } while (pud++, addr = next, addr != end);
-
-       return addr;
-}
-
-void page_table_reset_pgste(struct mm_struct *mm, unsigned long start,
-                           unsigned long end, bool init_skey)
-{
-       unsigned long addr, next;
-       pgd_t *pgd;
-
-       down_write(&mm->mmap_sem);
-       if (init_skey && mm_use_skey(mm))
-               goto out_up;
-       addr = start;
-       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, init_skey);
-       } while (pgd++, addr = next, addr != end);
-       if (init_skey)
-               current->mm->context.use_skey = 1;
-out_up:
-       up_write(&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)
 {
@@ -992,11 +899,6 @@ static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm)
        return NULL;
 }
 
-void page_table_reset_pgste(struct mm_struct *mm, unsigned long start,
-                           unsigned long end, bool init_skey)
-{
-}
-
 static inline void page_table_free_pgste(unsigned long *table)
 {
 }
@@ -1347,12 +1249,65 @@ 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)
+{
+       unsigned long ptev;
+       pgste_t pgste;
+
+       pgste = pgste_get_lock(pte);
+       /* Clear storage key */
+       pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT |
+                             PGSTE_GR_BIT | PGSTE_GC_BIT);
+       ptev = pte_val(*pte);
+       if (!(ptev & _PAGE_INVALID) && (ptev & _PAGE_WRITE))
+               page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 1);
+       pgste_set_unlock(pte, pgste);
+       return 0;
+}
+
 void s390_enable_skey(void)
 {
-       page_table_reset_pgste(current->mm, 0, TASK_SIZE, true);
+       struct mm_walk walk = { .pte_entry = __s390_enable_skey };
+       struct mm_struct *mm = current->mm;
+
+       down_write(&mm->mmap_sem);
+       if (mm_use_skey(mm))
+               goto out_up;
+       walk.mm = mm;
+       walk_page_range(0, TASK_SIZE, &walk);
+       mm->context.use_skey = 1;
+
+out_up:
+       up_write(&mm->mmap_sem);
 }
 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)
+{
+       pgste_t pgste;
+
+       pgste = pgste_get_lock(pte);
+       pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;
+       pgste_set_unlock(pte, pgste);
+       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);
+
 /*
  * Test and reset if a guest page is dirty
  */