s390/mm: Abstract gmap notify bit setting

Currently we use the software PGSTE bits PGSTE_IN_BIT and
PGSTE_VSIE_BIT to notify before an invalidation occurs on a prefix
page or a VSIE page respectively. Both bits are pgste specific, but
are used when protecting a memory range.

Let's introduce abstract GMAP_NOTIFY_* bits that will be realized into
the respective bits when gmap DAT table entries are protected.

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>

diff --git a/arch/s390/include/asm/gmap.h b/arch/s390/include/asm/gmap.h
index e07cce8..c1bc563 100644 (file)
--- a/arch/s390/include/asm/gmap.h
+++ b/arch/s390/include/asm/gmap.h
@@ -9,6 +9,10 @@
 #ifndef _ASM_S390_GMAP_H
 #define _ASM_S390_GMAP_H
 
+/* Generic bits for GMAP notification on DAT table entry changes. */
+#define GMAP_NOTIFY_SHADOW     0x2
+#define GMAP_NOTIFY_MPROT      0x1
+
 /**
  * struct gmap_struct - guest address space
  * @list: list head for the mm->context gmap list

diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index 71b0e9c..0bada5e 100644 (file)
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -912,7 +912,7 @@ static inline void gmap_pmd_op_end(struct gmap *gmap, pmd_t *pmdp)
  * @gaddr: virtual address in the guest address space
  * @pmdp: pointer to the pmd associated with the pte
  * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
- * @bits: pgste notification bits to set
+ * @bits: notification bits to set
  *
  * Returns 0 if successfully protected, -ENOMEM if out of memory and
  * -EAGAIN if a fixup is needed.
@@ -925,6 +925,7 @@ static int gmap_protect_pte(struct gmap *gmap, unsigned long gaddr,
        int rc;
        pte_t *ptep;
        spinlock_t *ptl = NULL;
+       unsigned long pbits = 0;
 
        if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)
                return -EAGAIN;
@@ -933,8 +934,10 @@ static int gmap_protect_pte(struct gmap *gmap, unsigned long gaddr,
        if (!ptep)
                return -ENOMEM;
 
+       pbits |= (bits & GMAP_NOTIFY_MPROT) ? PGSTE_IN_BIT : 0;
+       pbits |= (bits & GMAP_NOTIFY_SHADOW) ? PGSTE_VSIE_BIT : 0;
        /* Protect and unlock. */
-       rc = ptep_force_prot(gmap->mm, gaddr, ptep, prot, bits);
+       rc = ptep_force_prot(gmap->mm, gaddr, ptep, prot, pbits);
        gmap_pte_op_end(ptl);
        return rc;
 }
@@ -1008,7 +1011,7 @@ int gmap_mprotect_notify(struct gmap *gmap, unsigned long gaddr,
        if (!MACHINE_HAS_ESOP && prot == PROT_READ)
                return -EINVAL;
        down_read(&gmap->mm->mmap_sem);
-       rc = gmap_protect_range(gmap, gaddr, len, prot, PGSTE_IN_BIT);
+       rc = gmap_protect_range(gmap, gaddr, len, prot, GMAP_NOTIFY_MPROT);
        up_read(&gmap->mm->mmap_sem);
        return rc;
 }
@@ -1599,7 +1602,7 @@ struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
        down_read(&parent->mm->mmap_sem);
        rc = gmap_protect_range(parent, asce & _ASCE_ORIGIN,
                                ((asce & _ASCE_TABLE_LENGTH) + 1) * PAGE_SIZE,
-                               PROT_READ, PGSTE_VSIE_BIT);
+                               PROT_READ, GMAP_NOTIFY_SHADOW);
        up_read(&parent->mm->mmap_sem);
        spin_lock(&parent->shadow_lock);
        new->initialized = true;