kernel-ark/arch/x86/kernel/cpu/mcheck/winchip.c
Andy Lutomirski 375074cc73 x86: Clean up cr4 manipulation
CR4 manipulation was split, seemingly at random, between direct
(write_cr4) and using a helper (set/clear_in_cr4).  Unfortunately,
the set_in_cr4 and clear_in_cr4 helpers also poke at the boot code,
which only a small subset of users actually wanted.

This patch replaces all cr4 access in functions that don't leave cr4
exactly the way they found it with new helpers cr4_set_bits,
cr4_clear_bits, and cr4_set_bits_and_update_boot.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Vince Weaver <vince@deater.net>
Cc: "hillf.zj" <hillf.zj@alibaba-inc.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/495a10bdc9e67016b8fd3945700d46cfd5c12c2f.1414190806.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-04 12:10:41 +01:00

45 lines
1.1 KiB
C

/*
* IDT Winchip specific Machine Check Exception Reporting
* (C) Copyright 2002 Alan Cox <alan@lxorguk.ukuu.org.uk>
*/
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <asm/processor.h>
#include <asm/traps.h>
#include <asm/tlbflush.h>
#include <asm/mce.h>
#include <asm/msr.h>
/* Machine check handler for WinChip C6: */
static void winchip_machine_check(struct pt_regs *regs, long error_code)
{
enum ctx_state prev_state = ist_enter(regs);
printk(KERN_EMERG "CPU0: Machine Check Exception.\n");
add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
ist_exit(regs, prev_state);
}
/* Set up machine check reporting on the Winchip C6 series */
void winchip_mcheck_init(struct cpuinfo_x86 *c)
{
u32 lo, hi;
machine_check_vector = winchip_machine_check;
/* Make sure the vector pointer is visible before we enable MCEs: */
wmb();
rdmsr(MSR_IDT_FCR1, lo, hi);
lo |= (1<<2); /* Enable EIERRINT (int 18 MCE) */
lo &= ~(1<<4); /* Enable MCE */
wrmsr(MSR_IDT_FCR1, lo, hi);
cr4_set_bits(X86_CR4_MCE);
printk(KERN_INFO
"Winchip machine check reporting enabled on CPU#0.\n");
}