powerpc: Fix ioremap_flags() with book3e pte definition

commit 55052eec upstream.

We can't just clear the user read permission in book3e pte, because
that will also clear supervisor read permission.  This surely isn't
desired.  Fix the problem by adding the supervisor read back.

BenH: Slightly simplified the ifdef and applied to ppc64 too
Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

arch/powerpc/mm/pgtable_32.c

@@ -146,6 +146,14 @@ ioremap_flags(phys_addr_t addr, unsigned long size, unsigned long flags)
 	/* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
 	flags &= ~(_PAGE_USER | _PAGE_EXEC);
 
+#ifdef _PAGE_BAP_SR
+	/* _PAGE_USER contains _PAGE_BAP_SR on BookE using the new PTE format
+	 * which means that we just cleared supervisor access... oops ;-) This
+	 * restores it
+	 */
+	flags |= _PAGE_BAP_SR;
+#endif
+
 	return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
 }
 EXPORT_SYMBOL(ioremap_flags);

arch/powerpc/mm/pgtable_64.c

@@ -265,6 +265,14 @@ void __iomem * ioremap_flags(phys_addr_t addr, unsigned long size,
 	/* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
 	flags &= ~(_PAGE_USER | _PAGE_EXEC);
 
+#ifdef _PAGE_BAP_SR
+	/* _PAGE_USER contains _PAGE_BAP_SR on BookE using the new PTE format
+	 * which means that we just cleared supervisor access... oops ;-) This
+	 * restores it
+	 */
+	flags |= _PAGE_BAP_SR;
+#endif
+
 	if (ppc_md.ioremap)
 		return ppc_md.ioremap(addr, size, flags, caller);
 	return __ioremap_caller(addr, size, flags, caller);