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authorThomas Gleixner <tglx@linutronix.de>2021-10-22 00:55:11 +0200
committerBorislav Petkov <bp@suse.de>2021-10-26 10:18:09 +0200
commit23686ef25d4ae81bc12fe3994d1905191fcf71f8 (patch)
tree1df83e5f7ad25484ce845e6771185bde2421c065 /arch/x86/include/asm/fpu
parentx86/arch_prctl: Add controls for dynamic XSTATE components (diff)
downloadlinux-23686ef25d4ae81bc12fe3994d1905191fcf71f8.tar.xz
linux-23686ef25d4ae81bc12fe3994d1905191fcf71f8.zip
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 <tglx@linutronix.de> Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20211021225527.10184-8-chang.seok.bae@intel.com
Diffstat (limited to 'arch/x86/include/asm/fpu')
-rw-r--r--arch/x86/include/asm/fpu/xstate.h21
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h
index 43ae89d4bcd2..cf285464eabe 100644
--- a/arch/x86/include/asm/fpu/xstate.h
+++ b/arch/x86/include/asm/fpu/xstate.h
@@ -43,6 +43,9 @@
#define XFEATURE_MASK_USER_RESTORE \
(XFEATURE_MASK_USER_SUPPORTED & ~XFEATURE_MASK_PKRU)
+/* Features which are dynamically enabled for a process on request */
+#define XFEATURE_MASK_USER_DYNAMIC 0ULL
+
/* All currently supported supervisor features */
#define XFEATURE_MASK_SUPERVISOR_SUPPORTED (XFEATURE_MASK_PASID)
@@ -96,4 +99,22 @@ int xfeature_size(int xfeature_nr);
void xsaves(struct xregs_state *xsave, u64 mask);
void xrstors(struct xregs_state *xsave, u64 mask);
+#ifdef CONFIG_X86_64
+DECLARE_STATIC_KEY_FALSE(__fpu_state_size_dynamic);
+#endif
+
+#ifdef CONFIG_X86_64
+DECLARE_STATIC_KEY_FALSE(__fpu_state_size_dynamic);
+
+static __always_inline __pure bool fpu_state_size_dynamic(void)
+{
+ return static_branch_unlikely(&__fpu_state_size_dynamic);
+}
+#else
+static __always_inline __pure bool fpu_state_size_dynamic(void)
+{
+ return false;
+}
+#endif
+
#endif