From 23686ef25d4ae81bc12fe3994d1905191fcf71f8 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 21 Oct 2021 15:55:11 -0700 Subject: x86/fpu: Add basic helpers for dynamically enabled features To allow building up the infrastructure required to support dynamically enabled FPU features, add: - XFEATURES_MASK_DYNAMIC This constant will hold xfeatures which can be dynamically enabled. - fpu_state_size_dynamic() A static branch for 64-bit and a simple 'return false' for 32-bit. This helper allows to add dynamic-feature-specific changes to common code which is shared between 32-bit and 64-bit without #ifdeffery. Signed-off-by: Thomas Gleixner Signed-off-by: Chang S. Bae Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20211021225527.10184-8-chang.seok.bae@intel.com --- arch/x86/kernel/fpu/core.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index b05f6a3b2057..4018083c5b36 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -25,6 +25,10 @@ #define CREATE_TRACE_POINTS #include +#ifdef CONFIG_X86_64 +DEFINE_STATIC_KEY_FALSE(__fpu_state_size_dynamic); +#endif + /* The FPU state configuration data for kernel and user space */ struct fpu_state_config fpu_kernel_cfg __ro_after_init; struct fpu_state_config fpu_user_cfg __ro_after_init; -- cgit v1.2.3