[PATCH V3 04/30] powerpc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

Anshuman Khandual
2022-02-28T10:49:38Z

This defines and exports a platform specific custom vm_get_page_prot() via
subscribing ARCH_HAS_VM_GET_PAGE_PROT. Subsequently all __SXXX and __PXXX
macros can be dropped which are no longer needed. While here, this also
localizes arch_vm_get_page_prot() as powerpc_vm_get_page_prot() and moves
it near vm_get_page_prot().

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
arch/powerpc/Kconfig | 1 +
arch/powerpc/include/asm/mman.h | 12 ------
arch/powerpc/include/asm/pgtable.h | 19 ----------
arch/powerpc/mm/mmap.c | 59 ++++++++++++++++++++++++++++++
4 files changed, 60 insertions(+), 31 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index b779603978e1..ddb4a3687c05 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -135,6 +135,7 @@ config PPC
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAS_UACCESS_FLUSHCACHE
select ARCH_HAS_UBSAN_SANITIZE_ALL
+ select ARCH_HAS_VM_GET_PAGE_PROT
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select ARCH_KEEP_MEMBLOCK
select ARCH_MIGHT_HAVE_PC_PARPORT
diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
index 7cb6d18f5cd6..1b024e64c8ec 100644
--- a/arch/powerpc/include/asm/mman.h
+++ b/arch/powerpc/include/asm/mman.h
@@ -24,18 +24,6 @@ static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
}
#define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)

-static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
-{
-#ifdef CONFIG_PPC_MEM_KEYS
- return (vm_flags & VM_SAO) ?
- __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
- __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
-#else
- return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
-#endif
-}
-#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
-
static inline bool arch_validate_prot(unsigned long prot, unsigned long addr)
{
if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_SAO))
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index d564d0ecd4cd..3cbb6de20f9d 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -20,25 +20,6 @@ struct mm_struct;
#include <asm/nohash/pgtable.h>
#endif /* !CONFIG_PPC_BOOK3S */

-/* Note due to the way vm flags are laid out, the bits are XWR */
-#define __P000 PAGE_NONE
-#define __P001 PAGE_READONLY
-#define __P010 PAGE_COPY
-#define __P011 PAGE_COPY
-#define __P100 PAGE_READONLY_X
-#define __P101 PAGE_READONLY_X
-#define __P110 PAGE_COPY_X
-#define __P111 PAGE_COPY_X
-
-#define __S000 PAGE_NONE
-#define __S001 PAGE_READONLY
-#define __S010 PAGE_SHARED
-#define __S011 PAGE_SHARED
-#define __S100 PAGE_READONLY_X
-#define __S101 PAGE_READONLY_X
-#define __S110 PAGE_SHARED_X
-#define __S111 PAGE_SHARED_X
-
#ifndef __ASSEMBLY__

#ifndef MAX_PTRS_PER_PGD
diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c
index c475cf810aa8..ee275937fe19 100644
--- a/arch/powerpc/mm/mmap.c
+++ b/arch/powerpc/mm/mmap.c
@@ -254,3 +254,62 @@ void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)
mm->get_unmapped_area = arch_get_unmapped_area_topdown;
}
}
+
+static inline pgprot_t __vm_get_page_prot(unsigned long vm_flags)
+{
+ switch (vm_flags & (VM_READ | VM_WRITE | VM_EXEC | VM_SHARED)) {
+ case VM_NONE:
+ return PAGE_NONE;
+ case VM_READ:
+ return PAGE_READONLY;
+ case VM_WRITE:
+ case VM_WRITE | VM_READ:
+ return PAGE_COPY;
+ case VM_EXEC:
+ case VM_EXEC | VM_READ:
+ return PAGE_READONLY_X;
+ case VM_EXEC | VM_WRITE:
+ case VM_EXEC | VM_WRITE | VM_READ:
+ return PAGE_COPY_X;
+ case VM_SHARED:
+ return PAGE_NONE;
+ case VM_SHARED | VM_READ:
+ return PAGE_READONLY;
+ case VM_SHARED | VM_WRITE:
+ case VM_SHARED | VM_WRITE | VM_READ:
+ return PAGE_SHARED;
+ case VM_SHARED | VM_EXEC:
+ case VM_SHARED | VM_EXEC | VM_READ:
+ return PAGE_READONLY_X;
+ case VM_SHARED | VM_EXEC | VM_WRITE:
+ case VM_SHARED | VM_EXEC | VM_WRITE | VM_READ:
+ return PAGE_SHARED_X;
+ default:
+ BUILD_BUG();
+ }
+}
+
+#ifdef CONFIG_PPC64
+static pgprot_t powerpc_vm_get_page_prot(unsigned long vm_flags)
+{
+#ifdef CONFIG_PPC_MEM_KEYS
+ return (vm_flags & VM_SAO) ?
+ __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
+ __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
+#else
+ return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
+#endif
+}
+#else
+static pgprot_t powerpc_vm_get_page_prot(unsigned long vm_flags)
+{
+ return __pgprot(0);
+}
+#endif /* CONFIG_PPC64 */
+
+pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+ return __pgprot(pgprot_val(__vm_get_page_prot(vm_flags)) |
+ pgprot_val(powerpc_vm_get_page_prot(vm_flags)));
+}
+EXPORT_SYMBOL(vm_get_page_prot);
--
2.25.1