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authorDave Kleikamp <shaggy@linux.vnet.ibm.com>2008-07-08 00:28:54 +1000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2008-07-09 16:30:45 +1000
commitef3d3246a0d06be622867d21af25f997aeeb105f (patch)
tree9f0ae1913e0e637ec3aa104cc5e81557e5661b3c /arch/powerpc
parent379070491e1e744a59e69e5bcf3765012d15ecb4 (diff)
powerpc/mm: Add Strong Access Ordering support
Allow an application to enable Strong Access Ordering on specific pages of memory on Power 7 hardware. Currently, power has a weaker memory model than x86. Implementing a stronger memory model allows an emulator to more efficiently translate x86 code into power code, resulting in faster code execution. On Power 7 hardware, storing 0b1110 in the WIMG bits of the hpte enables strong access ordering mode for the memory page. This patchset allows a user to specify which pages are thus enabled by passing a new protection bit through mmap() and mprotect(). I have defined PROT_SAO to be 0x10. Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/kernel/syscalls.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c
index 4fe69ca24481..c04832c4a02e 100644
--- a/arch/powerpc/kernel/syscalls.c
+++ b/arch/powerpc/kernel/syscalls.c
@@ -143,6 +143,9 @@ static inline unsigned long do_mmap2(unsigned long addr, size_t len,
struct file * file = NULL;
unsigned long ret = -EINVAL;
+ if (!arch_validate_prot(prot))
+ goto out;
+
if (shift) {
if (off & ((1 << shift) - 1))
goto out;