The suspend code accesses FPU state internals, add a helper for
it and isolate it.
Reviewed-by: Borislav Petkov <b...@alien8.de>
Cc: Andy Lutomirski <l...@amacapital.net>
Cc: Dave Hansen <dave.han...@linux.intel.com>
Cc: Fenghua Yu <fenghua...@intel.com>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Oleg Nesterov <o...@redhat.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
arch/x86/include/asm/fpu/api.h | 1 +
arch/x86/kernel/fpu/xsave.c | 12 ++++++++++++
arch/x86/power/cpu.c | 10 ++--------
3 files changed, 15 insertions(+), 8 deletions(-)
diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h
index f1eddcccba16..5bdde8ca87bc 100644
--- a/arch/x86/include/asm/fpu/api.h
+++ b/arch/x86/include/asm/fpu/api.h
@@ -23,6 +23,7 @@ extern void fpu__clear(struct task_struct *tsk);
extern int dump_fpu(struct pt_regs *, struct user_i387_struct *);
extern void fpu__restore(void);
extern void fpu__init_check_bugs(void);
+extern void fpu__resume_cpu(void);
extern bool irq_fpu_usable(void);
diff --git a/arch/x86/kernel/fpu/xsave.c b/arch/x86/kernel/fpu/xsave.c
index 1d0e27128f18..a485180ebc32 100644
--- a/arch/x86/kernel/fpu/xsave.c
+++ b/arch/x86/kernel/fpu/xsave.c
@@ -735,6 +735,18 @@ void __init_refok eager_fpu_init(void)
}
/*
+ * Restore minimal FPU state after suspend:
+ */
+void fpu__resume_cpu(void)
+{
+ /*
+ * Restore XCR0 on xsave capable CPUs:
+ */
+ if (cpu_has_xsave)
+ xsetbv(XCR_XFEATURE_ENABLED_MASK, xfeatures_mask);
+}
+
+/*
* Given the xsave area and a state inside, this function returns the
* address of the state.
*
diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
index 62054acbd0d8..ad0ce6b70fac 100644
--- a/arch/x86/power/cpu.c
+++ b/arch/x86/power/cpu.c
@@ -18,10 +18,8 @@
#include <asm/mtrr.h>
#include <asm/page.h>
#include <asm/mce.h>
-#include <asm/xcr.h>
#include <asm/suspend.h>
#include <asm/debugreg.h>
-#include <asm/fpu/internal.h> /* xfeatures_mask */
#include <asm/cpu.h>
#ifdef CONFIG_X86_32
@@ -155,6 +153,8 @@ static void fix_processor_context(void)
#endif
load_TR_desc(); /* This does ltr */
load_LDT(¤t->active_mm->context); /* This does lldt */
+
+ fpu__resume_cpu();
}
/**
@@ -221,12 +221,6 @@ static void notrace __restore_processor_state(struct
saved_context *ctxt)
wrmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base);
#endif
- /*
- * restore XCR0 for xsave capable cpu's.
- */
- if (cpu_has_xsave)
- xsetbv(XCR_XFEATURE_ENABLED_MASK, xfeatures_mask);
-
fix_processor_context();
do_fpu_end();
--
2.1.0
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