powerpc/mm: Allow platforms to redefine some helpers

The 40xx defines _PAGE_HWWRITE while others don't.
The 8xx defines _PAGE_RO instead of _PAGE_RW.
The 8xx defines _PAGE_PRIVILEGED instead of _PAGE_USER.
The 8xx defines _PAGE_HUGE and _PAGE_NA while others don't.

Lets those platforms redefine pte_write(), pte_wrprotect() and
pte_mkwrite() and get _PAGE_RO and _PAGE_HWWRITE off the common
helpers.

Lets the 8xx redefine pte_user(), pte_mkprivileged() and pte_mkuser()
and get rid of _PAGE_PRIVILEGED and _PAGE_USER default values.

Lets the 8xx redefine pte_mkhuge() and get rid of
_PAGE_HUGE default value.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

3 files changed, 73 insertions, 10 deletions

diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h b/arch/powerpc/include/asm/nohash/32/pgtable.h
index a4156da4a7a4..ce9270a0ea42 100644
--- a/arch/powerpc/include/asm/nohash/32/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/32/pgtable.h
@@ -136,14 +136,12 @@ extern int icache_44x_need_flush;
 #define pte_clear(mm, addr, ptep) \
 	do { pte_update(ptep, ~0, 0); } while (0)
 
+#ifndef pte_mkwrite
 static inline pte_t pte_mkwrite(pte_t pte)
 {
-	pte_basic_t ptev;
-
-	ptev = pte_val(pte) & ~_PAGE_RO;
-	ptev |= _PAGE_RW;
-	return __pte(ptev);
+	return __pte(pte_val(pte) | _PAGE_RW);
 }
+#endif
 
 static inline pte_t pte_mkdirty(pte_t pte)
 {
@@ -155,14 +153,12 @@ static inline pte_t pte_mkyoung(pte_t pte)
 	return __pte(pte_val(pte) | _PAGE_ACCESSED);
 }
 
+#ifndef pte_wrprotect
 static inline pte_t pte_wrprotect(pte_t pte)
 {
-	pte_basic_t ptev;
-
-	ptev = pte_val(pte) & ~(_PAGE_RW | _PAGE_HWWRITE);
-	ptev |= _PAGE_RO;
-	return __pte(ptev);
+	return __pte(pte_val(pte) & ~_PAGE_RW);
 }
+#endif
 
 static inline pte_t pte_mkexec(pte_t pte)
 {
diff --git a/arch/powerpc/include/asm/nohash/32/pte-40x.h b/arch/powerpc/include/asm/nohash/32/pte-40x.h
index 2b48bc289a4d..ab043b3e9b99 100644
--- a/arch/powerpc/include/asm/nohash/32/pte-40x.h
+++ b/arch/powerpc/include/asm/nohash/32/pte-40x.h
@@ -87,5 +87,21 @@
 #define PAGE_READONLY	__pgprot(_PAGE_BASE | _PAGE_USER)
 #define PAGE_READONLY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
 
+#ifndef __ASSEMBLY__
+static inline pte_t pte_wrprotect(pte_t pte)
+{
+	return __pte(pte_val(pte) & ~(_PAGE_RW | _PAGE_HWWRITE));
+}
+
+#define pte_wrprotect pte_wrprotect
+
+static inline pte_t pte_mkclean(pte_t pte)
+{
+	return __pte(pte_val(pte) & ~(_PAGE_DIRTY | _PAGE_HWWRITE));
+}
+
+#define pte_mkclean pte_mkclean
+#endif
+
 #endif /* __KERNEL__ */
 #endif /*  _ASM_POWERPC_NOHASH_32_PTE_40x_H */
diff --git a/arch/powerpc/include/asm/nohash/32/pte-8xx.h b/arch/powerpc/include/asm/nohash/32/pte-8xx.h
index d06fc45bd9ac..b899c3c877ac 100644
--- a/arch/powerpc/include/asm/nohash/32/pte-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/pte-8xx.h
@@ -87,5 +87,56 @@
 #define PAGE_READONLY	__pgprot(_PAGE_BASE | _PAGE_RO)
 #define PAGE_READONLY_X	__pgprot(_PAGE_BASE | _PAGE_RO | _PAGE_EXEC)
 
+#ifndef __ASSEMBLY__
+static inline pte_t pte_wrprotect(pte_t pte)
+{
+	return __pte(pte_val(pte) | _PAGE_RO);
+}
+
+#define pte_wrprotect pte_wrprotect
+
+static inline int pte_write(pte_t pte)
+{
+	return !(pte_val(pte) & _PAGE_RO);
+}
+
+#define pte_write pte_write
+
+static inline pte_t pte_mkwrite(pte_t pte)
+{
+	return __pte(pte_val(pte) & ~_PAGE_RO);
+}
+
+#define pte_mkwrite pte_mkwrite
+
+static inline bool pte_user(pte_t pte)
+{
+	return !(pte_val(pte) & _PAGE_PRIVILEGED);
+}
+
+#define pte_user pte_user
+
+static inline pte_t pte_mkprivileged(pte_t pte)
+{
+	return __pte(pte_val(pte) | _PAGE_PRIVILEGED);
+}
+
+#define pte_mkprivileged pte_mkprivileged
+
+static inline pte_t pte_mkuser(pte_t pte)
+{
+	return __pte(pte_val(pte) & ~_PAGE_PRIVILEGED);
+}
+
+#define pte_mkuser pte_mkuser
+
+static inline pte_t pte_mkhuge(pte_t pte)
+{
+	return __pte(pte_val(pte) | _PAGE_HUGE);
+}
+
+#define pte_mkhuge pte_mkhuge
+#endif
+
 #endif /* __KERNEL__ */
 #endif /*  _ASM_POWERPC_NOHASH_32_PTE_8xx_H */