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| author | Dave Martin <Dave.Martin@arm.com> | 2018-04-12 16:47:20 +0100 |
|---|---|---|
| committer | Marc Zyngier <marc.zyngier@arm.com> | 2018-05-25 12:28:29 +0100 |
| commit | 31dc52b3c8faf47bf3ff5ced661488a20e5d1811 (patch) | |
| tree | 39ec9ba8565964bcceae7494bfdb8e7c1c94cb3c /arch/arm64/kernel | |
| parent | e6b673b741ea0d7cd275ad40748bfc225accc423 (diff) | |
| download | op-kernel-dev-31dc52b3c8faf47bf3ff5ced661488a20e5d1811.zip op-kernel-dev-31dc52b3c8faf47bf3ff5ced661488a20e5d1811.tar.gz | |
arm64/sve: Move read_zcr_features() out of cpufeature.h
Having read_zcr_features() inline in cpufeature.h results in that
header requiring #includes which make it hard to include
<asm/fpsimd.h> elsewhere without triggering header inclusion
cycles.
This is not a hot-path function and arguably should not be in
cpufeature.h in the first place, so this patch moves it to
fpsimd.c, compiled conditionally if CONFIG_ARM64_SVE=y.
This allows some SVE-related #includes to be dropped from
cpufeature.h, which will ease future maintenance.
A couple of missing #includes of <asm/fpsimd.h> are exposed by this
change under arch/arm64/. This patch adds the missing #includes as
necessary.
No functional change.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/fpsimd.c | 28 | ||||
| -rw-r--r-- | arch/arm64/kernel/ptrace.c | 1 |
2 files changed, 29 insertions, 0 deletions
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 794dd99..6c01ee2 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -37,6 +37,7 @@ #include <linux/sched/task_stack.h> #include <linux/signal.h> #include <linux/slab.h> +#include <linux/stddef.h> #include <linux/sysctl.h> #include <asm/esr.h> @@ -755,6 +756,33 @@ void sve_kernel_enable(const struct arm64_cpu_capabilities *__always_unused p) isb(); } +/* + * Read the pseudo-ZCR used by cpufeatures to identify the supported SVE + * vector length. + * + * Use only if SVE is present. + * This function clobbers the SVE vector length. + */ +u64 read_zcr_features(void) +{ + u64 zcr; + unsigned int vq_max; + + /* + * Set the maximum possible VL, and write zeroes to all other + * bits to see if they stick. + */ + sve_kernel_enable(NULL); + write_sysreg_s(ZCR_ELx_LEN_MASK, SYS_ZCR_EL1); + + zcr = read_sysreg_s(SYS_ZCR_EL1); + zcr &= ~(u64)ZCR_ELx_LEN_MASK; /* find sticky 1s outside LEN field */ + vq_max = sve_vq_from_vl(sve_get_vl()); + zcr |= vq_max - 1; /* set LEN field to maximum effective value */ + + return zcr; +} + void __init sve_setup(void) { u64 zcr; diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 7ff81fe..78889c4 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -44,6 +44,7 @@ #include <asm/compat.h> #include <asm/cpufeature.h> #include <asm/debug-monitors.h> +#include <asm/fpsimd.h> #include <asm/pgtable.h> #include <asm/stacktrace.h> #include <asm/syscall.h> |
