[PATCH v5 11/25] mm: Introduce arch_calc_vm_flag_bits()

Catalin Marinas
2020-06-24T17:53:14Z

From: Kevin Brodsky <Kevin.Brodsky@arm.com>

Similarly to arch_calc_vm_prot_bits(), introduce a dummy
arch_calc_vm_flag_bits() invoked from calc_vm_flag_bits(). This macro
can be overridden by architectures to insert specific VM_* flags derived
from the mmap() MAP_* flags.

Signed-off-by: Kevin Brodsky <Kevin.Brodsky@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---

Notes:
v2:
- Updated the comment above arch_calc_vm_prot_bits().
- Changed author since this patch had already been posted (internally).

include/linux/mman.h | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/include/linux/mman.h b/include/linux/mman.h
index 4b08e9c9c538..15c1162b9d65 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -74,13 +74,17 @@ static inline void vm_unacct_memory(long pages)
}

/*
- * Allow architectures to handle additional protection bits
+ * Allow architectures to handle additional protection and flag bits
*/

#ifndef arch_calc_vm_prot_bits
#define arch_calc_vm_prot_bits(prot, pkey) 0
#endif

+#ifndef arch_calc_vm_flag_bits
+#define arch_calc_vm_flag_bits(flags) 0
+#endif
+
#ifndef arch_vm_get_page_prot
#define arch_vm_get_page_prot(vm_flags) __pgprot(0)
#endif
@@ -131,7 +135,8 @@ calc_vm_flag_bits(unsigned long flags)
return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) |
_calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) |
_calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) |
- _calc_vm_trans(flags, MAP_SYNC, VM_SYNC );
+ _calc_vm_trans(flags, MAP_SYNC, VM_SYNC ) |
+ arch_calc_vm_flag_bits(flags);
}

unsigned long vm_commit_limit(void);