From: Fenghua Yu <[email protected]> Since cpu caps are not enabled yet during early booting time, alternative can not be used in functions to access xsave area. Therefore, we define two new functions xrstor_state_booting and xsave_state_booting to access xsave area during early booting time.
Because xsave_state_booting() can be called by run-time function __save_fpu(), it's not defined as __init and will stay in memory during running time. But it's a small function and the memory cost is small. Signed-off-by: Fenghua Yu <[email protected]> --- arch/x86/include/asm/xsave.h | 60 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h index a8f31d0..0de695d 100644 --- a/arch/x86/include/asm/xsave.h +++ b/arch/x86/include/asm/xsave.h @@ -66,6 +66,66 @@ extern int init_fpu(struct task_struct *child); : [err] "=r" (err) /* + * This function is called only during boot time when x86 caps are not set + * up and alternative can not be used yet. + */ +static void xsave_state_booting(struct xsave_struct *fx, u64 mask) +{ + u32 lmask = mask; + u32 hmask = mask >> 32; + int err = 0; + + WARN_ON(system_state != SYSTEM_BOOTING); + + if (boot_cpu_has(X86_FEATURE_XSAVES)) + asm volatile("1:"XSAVES"\n\t" + "2:\n\t" + : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask) + : "memory"); + else + asm volatile("1:"XSAVE"\n\t" + "2:\n\t" + : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask) + : "memory"); + + asm volatile(xstate_fault + : "0" (0) + : "memory"); + + return err; +} + +/* + * This function is called only during boot time when x86 caps are not set + * up and alternative can not be used yet. + */ +static inline int xrstor_state_booting(struct xsave_struct *fx, u64 mask) +{ + u32 lmask = mask; + u32 hmask = mask >> 32; + int err = 0; + + WARN_ON(system_state != SYSTEM_BOOTING); + + if (boot_cpu_has(X86_FEATURE_XSAVES)) + asm volatile("1:"XRSTORS"\n\t" + "2:\n\t" + : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask) + : "memory"); + else + asm volatile("1:"XRSTOR"\n\t" + "2:\n\t" + : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask) + : "memory"); + + asm volatile(xstate_fault + : "0" (0) + : "memory"); + + return err; +} + +/* * Save processor xstate to xsave area. */ static inline void xsave_state(struct xsave_struct *fx, u64 mask) -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
