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authorWill Deacon <will.deacon@arm.com>2011-06-08 11:42:43 +0100
committerWill Deacon <will.deacon@arm.com>2011-07-07 19:20:52 +0100
commit18b9dc130c33de2d1fd46bd668e67d0e1a544b16 (patch)
tree6baac3359f06737ab27d28d2c29311334aa39313 /arch/arm/vfp
parent254cdf8ec39653d19cce71b6622f38a6b62ac3a8 (diff)
downloadop-kernel-dev-18b9dc130c33de2d1fd46bd668e67d0e1a544b16.zip
op-kernel-dev-18b9dc130c33de2d1fd46bd668e67d0e1a544b16.tar.gz
ARM: vfp: add VFPv4 capability detection and populate elf_hwcap
The presence of VFPv4 cannot be detected simply by looking at the FPSID subarchitecture field, as a value >= 2 signifies the architecture as VFPv3 or later. This patch reads from MVFR1 to check whether or not the fused multiply accumulate instructions are supported. Since these are introduced with VFPv4, this tells us what we need to know. Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm/vfp')
-rw-r--r--arch/arm/vfp/vfpmodule.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index f25e7ec..650d90b 100644
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -582,7 +582,6 @@ static int __init vfp_init(void)
elf_hwcap |= HWCAP_VFPv3D16;
}
#endif
-#ifdef CONFIG_NEON
/*
* Check for the presence of the Advanced SIMD
* load/store instructions, integer and single
@@ -590,10 +589,13 @@ static int __init vfp_init(void)
* for NEON if the hardware has the MVFR registers.
*/
if ((read_cpuid_id() & 0x000f0000) == 0x000f0000) {
+#ifdef CONFIG_NEON
if ((fmrx(MVFR1) & 0x000fff00) == 0x00011100)
elf_hwcap |= HWCAP_NEON;
- }
#endif
+ if ((fmrx(MVFR1) & 0xf0000000) == 0x10000000)
+ elf_hwcap |= HWCAP_VFPv4;
+ }
}
return 0;
}
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