x86/traps: Document do_spurious_interrupt_bug() (d244d0e1) · Commits · 戴 / test

arch/x86/kernel/traps.c

+19 −0

Original line number	Diff line number	Diff line
		@@ -862,6 +862,25 @@ do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
		dotraplinkage void
		do_spurious_interrupt_bug(struct pt_regs *regs, long error_code)
		{
		/*
		* This addresses a Pentium Pro Erratum:
		*
		* PROBLEM: If the APIC subsystem is configured in mixed mode with
		* Virtual Wire mode implemented through the local APIC, an
		* interrupt vector of 0Fh (Intel reserved encoding) may be
		* generated by the local APIC (Int 15). This vector may be
		* generated upon receipt of a spurious interrupt (an interrupt
		* which is removed before the system receives the INTA sequence)
		* instead of the programmed 8259 spurious interrupt vector.
		*
		* IMPLICATION: The spurious interrupt vector programmed in the
		* 8259 is normally handled by an operating system's spurious
		* interrupt handler. However, a vector of 0Fh is unknown to some
		* operating systems, which would crash if this erratum occurred.
		*
		* In theory this could be limited to 32bit, but the handler is not
		* hurting and who knows which other CPUs suffer from this.
		*/
		}

		dotraplinkage void