powerpc/mm: Use _PAGE_READ to indicate Read access
This splits the _PAGE_RW bit into _PAGE_READ and _PAGE_WRITE. It also
removes the dependency on _PAGE_USER for implying read only. Few things
to note here is that, we have read implied with write and execute
permission. Hence we should always find _PAGE_READ set on hash pte
fault.
We still can't switch PROT_NONE to !(_PAGE_RWX). Auto numa depends on
marking a prot none pte _PAGE_WRITE. (For more details look at
b191f9b106ea "mm: numa: preserve PTE write permissions across a NUMA
hinting fault")
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 7635b1c..ed190e4 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -175,8 +175,9 @@
* or PP=0x3 for read-only (including writeable but clean pages).
*/
if (pteflags & _PAGE_USER) {
- rflags |= 0x2;
- if (!((pteflags & _PAGE_RW) && (pteflags & _PAGE_DIRTY)))
+ if (pteflags & _PAGE_RWX)
+ rflags |= 0x2;
+ if (!((pteflags & _PAGE_WRITE) && (pteflags & _PAGE_DIRTY)))
rflags |= 0x1;
}
/*
@@ -1209,7 +1210,7 @@
int __hash_page(unsigned long ea, unsigned long msr, unsigned long trap,
unsigned long dsisr)
{
- unsigned long access = _PAGE_PRESENT;
+ unsigned long access = _PAGE_PRESENT | _PAGE_READ;
unsigned long flags = 0;
struct mm_struct *mm = current->mm;
@@ -1220,7 +1221,7 @@
flags |= HPTE_NOHPTE_UPDATE;
if (dsisr & DSISR_ISSTORE)
- access |= _PAGE_RW;
+ access |= _PAGE_WRITE;
/*
* We need to set the _PAGE_USER bit if MSR_PR is set or if we are
* accessing a userspace segment (even from the kernel). We assume