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Commit 1bd12c91 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86/nuke386' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull one final 386 removal patch from Peter Anvin.

IRQ 13 FPU error handling is gone.  That was not one of the proudest
moments in PC history.

* 'x86/nuke386' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, 386 removal: Remove support for IRQ 13 FPU error reporting
parents 3dbff0d5 bc3eba60

arch/x86/kernel/cpu/proc.c

+1 −6
Original line number Diff line number Diff line
@@ -26,11 +26,6 @@ static void show_cpuinfo_core(struct seq_file *m, struct cpuinfo_x86 *c, 
#ifdef CONFIG_X86_32

static void show_cpuinfo_misc(struct seq_file *m, struct cpuinfo_x86 *c)

{

	/*

	 * We use exception 16 if we have hardware math and we've either seen

	 * it or the CPU claims it is internal

	 */

	int fpu_exception = c->hard_math && (ignore_fpu_irq || cpu_has_fpu);

	seq_printf(m,

		   "fdiv_bug\t: %s\n"

		   "hlt_bug\t\t: %s\n"
@@ -45,7 +40,7 @@ static void show_cpuinfo_misc(struct seq_file *m, struct cpuinfo_x86 *c) 
		   c->f00f_bug ? "yes" : "no",

		   c->coma_bug ? "yes" : "no",

		   c->hard_math ? "yes" : "no",

		   fpu_exception ? "yes" : "no",

		   c->hard_math ? "yes" : "no",

		   c->cpuid_level,

		   c->wp_works_ok ? "yes" : "no");

}

arch/x86/kernel/irqinit.c

+0 −40
Original line number Diff line number Diff line
@@ -42,39 +42,6 @@ 
 * (these are usually mapped into the 0x30-0xff vector range)

 */



#ifdef CONFIG_X86_32

/*

 * Note that on a 486, we don't want to do a SIGFPE on an irq13

 * as the irq is unreliable, and exception 16 works correctly

 * (ie as explained in the intel literature). On a 386, you

 * can't use exception 16 due to bad IBM design, so we have to

 * rely on the less exact irq13.

 *

 * Careful.. Not only is IRQ13 unreliable, but it is also

 * leads to races. IBM designers who came up with it should

 * be shot.

 */



static irqreturn_t math_error_irq(int cpl, void *dev_id)

{

	outb(0, 0xF0);

	if (ignore_fpu_irq || !boot_cpu_data.hard_math)

		return IRQ_NONE;

	math_error(get_irq_regs(), 0, X86_TRAP_MF);

	return IRQ_HANDLED;

}



/*

 * New motherboards sometimes make IRQ 13 be a PCI interrupt,

 * so allow interrupt sharing.

 */

static struct irqaction fpu_irq = {

	.handler = math_error_irq,

	.name = "fpu",

	.flags = IRQF_NO_THREAD,

};

#endif



/*

 * IRQ2 is cascade interrupt to second interrupt controller

 */
@@ -242,13 +209,6 @@ void __init native_init_IRQ(void) 
		setup_irq(2, &irq2);



#ifdef CONFIG_X86_32

	/*

	 * External FPU? Set up irq13 if so, for

	 * original braindamaged IBM FERR coupling.

	 */

	if (boot_cpu_data.hard_math && !cpu_has_fpu)

		setup_irq(FPU_IRQ, &fpu_irq);



	irq_ctx_init(smp_processor_id());

#endif

}

arch/x86/kernel/traps.c

+0 −6
Original line number Diff line number Diff line
@@ -69,9 +69,6 @@ 


asmlinkage int system_call(void);



/* Do we ignore FPU interrupts ? */

char ignore_fpu_irq;



/*

 * The IDT has to be page-aligned to simplify the Pentium

 * F0 0F bug workaround.
@@ -564,9 +561,6 @@ void math_error(struct pt_regs *regs, int error_code, int trapnr) 


dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)

{

#ifdef CONFIG_X86_32

	ignore_fpu_irq = 1;

#endif

	exception_enter(regs);

	math_error(regs, error_code, X86_TRAP_MF);

	exception_exit(regs);