diff options
| author | Dave Kleikamp <shaggy@linux.vnet.ibm.com> | 2008-07-08 00:28:54 +1000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2008-07-09 16:30:45 +1000 |
| commit | ef3d3246a0d06be622867d21af25f997aeeb105f (patch) | |
| tree | 9f0ae1913e0e637ec3aa104cc5e81557e5661b3c | |
| parent | 379070491e1e744a59e69e5bcf3765012d15ecb4 (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>
| -rw-r--r-- | arch/powerpc/kernel/syscalls.c | 3 | ||||
| -rw-r--r-- | include/asm-powerpc/mman.h | 30 |
2 files changed, 33 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; diff --git a/include/asm-powerpc/mman.h b/include/asm-powerpc/mman.h index 0c46bf2c7d5f..f8a32e20ba04 100644 --- a/include/asm-powerpc/mman.h +++ b/include/asm-powerpc/mman.h @@ -1,7 +1,9 @@ #ifndef _ASM_POWERPC_MMAN_H #define _ASM_POWERPC_MMAN_H +#include <asm/cputable.h> #include <asm-generic/mman.h> +#include <linux/mm.h> /* * This program is free software; you can redistribute it and/or @@ -26,4 +28,32 @@ #define MAP_POPULATE 0x8000 /* populate (prefault) pagetables */ #define MAP_NONBLOCK 0x10000 /* do not block on IO */ +#ifdef CONFIG_PPC64 +/* + * This file is included by linux/mman.h, so we can't use cacl_vm_prot_bits() + * here. How important is the optimization? + */ +static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot) +{ + return (prot & PROT_SAO) ? VM_SAO : 0; +} +#define arch_calc_vm_prot_bits(prot) arch_calc_vm_prot_bits(prot) + +static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags) +{ + return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : 0; +} +#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags) + +static inline int arch_validate_prot(unsigned long prot) +{ + if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_SAO)) + return 0; + if ((prot & PROT_SAO) && !cpu_has_feature(CPU_FTR_SAO)) + return 0; + return 1; +} +#define arch_validate_prot(prot) arch_validate_prot(prot) + +#endif /* CONFIG_PPC64 */ #endif /* _ASM_POWERPC_MMAN_H */ |