diff options
| author | Paul Burton <[email protected]> | 2015-07-27 12:58:23 -0700 |
|---|---|---|
| committer | Ralf Baechle <[email protected]> | 2015-09-03 12:07:59 +0200 |
| commit | e14f1db7a61f016d74393ca9e8fc49a91d27f603 (patch) | |
| tree | 42c39860145a108787727893e220c98813290aa0 | |
| parent | bf82cb30c7e58b3a9742f0a45962ebdf51befac7 (diff) | |
MIPS: AT_HWCAP aux vector infrastructure
In order for userland to determine whether various features are safe to
use, it will need to know both that the hardware supports those features
and that the kernel is recent enough & configured appropriately to
support them. For example under the O32 modeless FP proposal the dynamic
linker & ifunc resolvers will need this information. The kernel is the
only thing in a position to know availability accurately, so the kernel
needs to provide the information to userland. This patch introduces the
infrastructure to provide the AT_HWCAP aux vector to userland in order
to provide that information. It also defines the 2 currently specified
flags, which indicate MIPSr6 & MSA support.
Signed-off-by: Paul Burton <[email protected]>
Cc: [email protected]
Cc: Guenter Roeck <[email protected]>
Cc: Matthew Fortune <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: Maciej W. Rozycki <[email protected]>
Cc: Alex Smith <[email protected]>
Cc: [email protected]
Cc: Leonid Yegoshin <[email protected]>
Cc: Markos Chandras <[email protected]>
Cc: Ingo Molnar <[email protected]>
Patchwork: https://patchwork.linux-mips.org/patch/10797/
Signed-off-by: Ralf Baechle <[email protected]>
| -rw-r--r-- | arch/mips/include/asm/elf.h | 4 | ||||
| -rw-r--r-- | arch/mips/include/uapi/asm/hwcap.h | 8 | ||||
| -rw-r--r-- | arch/mips/kernel/cpu-probe.c | 3 |
3 files changed, 14 insertions, 1 deletions
diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h index f19e890b99d2..53b26933b12c 100644 --- a/arch/mips/include/asm/elf.h +++ b/arch/mips/include/asm/elf.h @@ -382,7 +382,9 @@ do { \ instruction set this cpu supports. This could be done in userspace, but it's not easy, and we've already done it here. */ -#define ELF_HWCAP (0) +#define ELF_HWCAP (elf_hwcap) +extern unsigned int elf_hwcap; +#include <asm/hwcap.h> /* * This yields a string that ld.so will use to load implementation diff --git a/arch/mips/include/uapi/asm/hwcap.h b/arch/mips/include/uapi/asm/hwcap.h new file mode 100644 index 000000000000..c7484a7ca686 --- /dev/null +++ b/arch/mips/include/uapi/asm/hwcap.h @@ -0,0 +1,8 @@ +#ifndef _UAPI_ASM_HWCAP_H +#define _UAPI_ASM_HWCAP_H + +/* HWCAP flags */ +#define HWCAP_MIPS_R6 (1 << 0) +#define HWCAP_MIPS_MSA (1 << 1) + +#endif /* _UAPI_ASM_HWCAP_H */ diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index 987036761fb6..b6c1feed8b7b 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -32,6 +32,9 @@ #include <asm/spram.h> #include <asm/uaccess.h> +/* Hardware capabilities */ +unsigned int elf_hwcap __read_mostly; + /* * Get the FPU Implementation/Revision. */ |