UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity

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>
This commit is contained in:
Will Deacon 2011-06-08 11:42:43 +01:00
parent 254cdf8ec3
commit 18b9dc130c
1 changed files with 4 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
arch/arm/vfp/vfpmodule.c
View File

@ -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;
}