diff options
| author | Tony Lindgren <tony@atomide.com> | 2010-07-01 13:41:05 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-07-09 14:41:34 +0100 |
| commit | 5aaf254409f8d58229107b59507a8235b715a960 (patch) | |
| tree | 30b3a289808a34a1db28a0eb6d92bc160be3bc0c /arch/arm | |
| parent | e513f8bf240d34bd6e732ba2f74df9ab84686ce6 (diff) | |
ARM: 6203/1: Make VFPv3 usable on ARMv6
MVFR0 and MVFR1 are only available starting with ARM1136 r1p0 release
according to "B.5 VFP changes" in DDI0211F_arm1136_r1p0_trm.pdf. This is
also when TLS register got added, so we can use HAS_TLS also to test for
MVFR0 and MVFR1.
Otherwise VFPFMRX and VFPFMXR access fails and we get:
Internal error: Oops - undefined instruction: 0 [#1]
PC is at no_old_VFP_process+0x8/0x3c
LR is at __und_svc+0x48/0x80
...
Signed-off-by: Tony Lindgren <tony@atomide.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/include/asm/vfpmacros.h | 18 | ||||
| -rw-r--r-- | arch/arm/vfp/vfpmodule.c | 10 |
2 files changed, 25 insertions, 3 deletions
diff --git a/arch/arm/include/asm/vfpmacros.h b/arch/arm/include/asm/vfpmacros.h index 422f3cc204a..3d5fc41ae8d 100644 --- a/arch/arm/include/asm/vfpmacros.h +++ b/arch/arm/include/asm/vfpmacros.h @@ -3,6 +3,8 @@ * * Assembler-only file containing VFP macros and register definitions. */ +#include <asm/hwcap.h> + #include "vfp.h" @ Macros to allow building with old toolkits (with no VFP support) @@ -22,12 +24,20 @@ LDC p11, cr0, [\base],#32*4 @ FLDMIAD \base!, {d0-d15} #endif #ifdef CONFIG_VFPv3 +#if __LINUX_ARM_ARCH__ <= 6 + ldr \tmp, =elf_hwcap @ may not have MVFR regs + ldr \tmp, [\tmp, #0] + tst \tmp, #HWCAP_VFPv3D16 + ldceq p11, cr0, [\base],#32*4 @ FLDMIAD \base!, {d16-d31} + addne \base, \base, #32*4 @ step over unused register space +#else VFPFMRX \tmp, MVFR0 @ Media and VFP Feature Register 0 and \tmp, \tmp, #MVFR0_A_SIMD_MASK @ A_SIMD field cmp \tmp, #2 @ 32 x 64bit registers? ldceql p11, cr0, [\base],#32*4 @ FLDMIAD \base!, {d16-d31} addne \base, \base, #32*4 @ step over unused register space #endif +#endif .endm @ write all the working registers out of the VFP @@ -38,10 +48,18 @@ STC p11, cr0, [\base],#32*4 @ FSTMIAD \base!, {d0-d15} #endif #ifdef CONFIG_VFPv3 +#if __LINUX_ARM_ARCH__ <= 6 + ldr \tmp, =elf_hwcap @ may not have MVFR regs + ldr \tmp, [\tmp, #0] + tst \tmp, #HWCAP_VFPv3D16 + stceq p11, cr0, [\base],#32*4 @ FSTMIAD \base!, {d16-d31} + addne \base, \base, #32*4 @ step over unused register space +#else VFPFMRX \tmp, MVFR0 @ Media and VFP Feature Register 0 and \tmp, \tmp, #MVFR0_A_SIMD_MASK @ A_SIMD field cmp \tmp, #2 @ 32 x 64bit registers? stceql p11, cr0, [\base],#32*4 @ FSTMIAD \base!, {d16-d31} addne \base, \base, #32*4 @ step over unused register space #endif +#endif .endm diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c index 315a540c7ce..8063a322c79 100644 --- a/arch/arm/vfp/vfpmodule.c +++ b/arch/arm/vfp/vfpmodule.c @@ -15,6 +15,7 @@ #include <linux/sched.h> #include <linux/init.h> +#include <asm/cputype.h> #include <asm/thread_notify.h> #include <asm/vfp.h> @@ -549,10 +550,13 @@ static int __init vfp_init(void) /* * Check for the presence of the Advanced SIMD * load/store instructions, integer and single - * precision floating point operations. + * precision floating point operations. Only check + * for NEON if the hardware has the MVFR registers. */ - if ((fmrx(MVFR1) & 0x000fff00) == 0x00011100) - elf_hwcap |= HWCAP_NEON; + if ((read_cpuid_id() & 0x000f0000) == 0x000f0000) { + if ((fmrx(MVFR1) & 0x000fff00) == 0x00011100) + elf_hwcap |= HWCAP_NEON; + } #endif } return 0; |