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| author | Dave Kleikamp <shaggy@linux.vnet.ibm.com> | 2008-07-07 16:28:54 +0200 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2008-07-09 08:30:45 +0200 |
| commit | ef3d3246a0d06be622867d21af25f997aeeb105f (patch) | |
| tree | 9f0ae1913e0e637ec3aa104cc5e81557e5661b3c /arch/powerpc/kernel/syscalls.c | |
| parent | powerpc/mm: Add SAO Feature bit to the cputable (diff) | |
| download | linux-ef3d3246a0d06be622867d21af25f997aeeb105f.tar.xz linux-ef3d3246a0d06be622867d21af25f997aeeb105f.zip | |
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/kernel/syscalls.c')
| -rw-r--r-- | arch/powerpc/kernel/syscalls.c | 3 |
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; |