Commit-ID: 55cc4678b7ee2edd3e6a9411250530eb871bc61d
Gitweb: http://git.kernel.org/tip/55cc4678b7ee2edd3e6a9411250530eb871bc61d
Author: Ingo Molnar <mingo@xxxxxxxxxx>
AuthorDate: Sat, 25 Apr 2015 06:26:36 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 19 May 2015 15:47:39 +0200
x86/fpu: Make the system/cpu init distinction clear in the xstate code as well
Rename existing xstate init functions along the system/cpu init principles:
fpu__init_system_xstate(): called once per system bootup
fpu__init_cpu_xstate(): called per CPU onlining
Also make the fpu__init_cpu_xstate() early code invariant:
if xfeatures_mask is not set yet then don't crash but return.
Reviewed-by: Borislav Petkov <bp@xxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/include/asm/fpu/internal.h | 3 +++
arch/x86/kernel/fpu/xsave.c | 22 ++++++++++++++--------
2 files changed, 17 insertions(+), 8 deletions(-)
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index 19b7cdf..71d44be 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -39,6 +39,9 @@ extern unsigned int mxcsr_feature_mask;
extern void fpu__cpu_init(void);
extern void eager_fpu_init(void);
+extern void fpu__init_system_xstate(void);
+extern void fpu__init_cpu_xstate(void);
+
DECLARE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx);
extern void convert_from_fxsr(struct user_i387_ia32_struct *env,
diff --git a/arch/x86/kernel/fpu/xsave.c b/arch/x86/kernel/fpu/xsave.c
index 45130ba..961c258 100644
--- a/arch/x86/kernel/fpu/xsave.c
+++ b/arch/x86/kernel/fpu/xsave.c
@@ -460,10 +460,14 @@ static void prepare_fx_sw_frame(void)
}
/*
- * Enable the extended processor state save/restore feature
+ * Enable the extended processor state save/restore feature.
+ * Called once per CPU onlining.
*/
-static inline void xstate_enable(void)
+void fpu__init_cpu_xstate(void)
{
+ if (!xfeatures_mask)
+ return;
+
cr4_set_bits(X86_CR4_OSXSAVE);
xsetbv(XCR_XFEATURE_ENABLED_MASK, xfeatures_mask);
}
@@ -640,11 +644,12 @@ static void __init init_xstate_size(void)
/*
* Enable and initialize the xsave feature.
+ * Called once per system bootup.
*
* ( Not marked __init because of false positive section warnings
* generated by xsave_init(). )
*/
-static void /* __init */ xstate_enable_boot_cpu(void)
+void fpu__init_system_xstate(void)
{
unsigned int eax, ebx, ecx, edx;
@@ -666,7 +671,8 @@ static void /* __init */ xstate_enable_boot_cpu(void)
*/
xfeatures_mask = xfeatures_mask & XCNTXT_MASK;
- xstate_enable();
+ /* Enable xstate instructions to be able to continue with initialization: */
+ fpu__init_cpu_xstate();
/*
* Recompute the context size for enabled features
@@ -698,8 +704,8 @@ static void /* __init */ xstate_enable_boot_cpu(void)
}
/*
- * For the very first instance, this calls xstate_enable_boot_cpu();
- * for all subsequent instances, this calls xstate_enable().
+ * For the very first instance, this calls fpu__init_system_xstate();
+ * for all subsequent instances, this calls fpu__init_cpu_xstate().
*/
void xsave_init(void)
{
@@ -715,9 +721,9 @@ void xsave_init(void)
if (on_boot_cpu) {
on_boot_cpu = 0;
- xstate_enable_boot_cpu();
+ fpu__init_system_xstate();
} else {
- xstate_enable();
+ fpu__init_cpu_xstate();
}
}
--
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