Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b7fb4af0 authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge Committed by Andi Kleen
Browse files

[PATCH] i386: Allow boot-time disable of SMP altinstructions



Add "noreplace-smp" to disable SMP instruction replacement.

Signed-off-by: default avatarJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
parent d0175ab6
Loading
Loading
Loading
Loading
+6 −0
Original line number Diff line number Diff line
@@ -1164,6 +1164,9 @@ and is between 256 and 4096 characters. It is defined in the file

	nomce		[IA-32] Machine Check Exception

	noreplace-smp	[IA-32,SMP] Don't replace SMP instructions
			with UP alternatives

	noresidual	[PPC] Don't use residual data on PReP machines.

	noresume	[SWSUSP] Disables resume and restores original swap
@@ -1569,6 +1572,9 @@ and is between 256 and 4096 characters. It is defined in the file
	smart2=		[HW]
			Format: <io1>[,<io2>[,...,<io8>]]

	smp-alt-once	[IA-32,SMP] On a hotplug CPU system, only
			attempt to substitute SMP alternatives once at boot.

	snd-ad1816a=	[HW,ALSA]

	snd-ad1848=	[HW,ALSA]
+19 −4
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@
#include <asm/alternative.h>
#include <asm/sections.h>

static int noreplace_smp     = 0;
static int smp_alt_once      = 0;
static int debug_alternative = 0;

@@ -13,15 +14,23 @@ static int __init bootonly(char *str)
	smp_alt_once = 1;
	return 1;
}
__setup("smp-alt-boot", bootonly);

static int __init debug_alt(char *str)
{
	debug_alternative = 1;
	return 1;
}

__setup("smp-alt-boot", bootonly);
__setup("debug-alternative", debug_alt);

static int __init setup_noreplace_smp(char *str)
{
	noreplace_smp = 1;
	return 1;
}
__setup("noreplace-smp", setup_noreplace_smp);


#define DPRINTK(fmt, args...) if (debug_alternative) \
	printk(KERN_DEBUG fmt, args)

@@ -185,6 +194,9 @@ static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end
{
	u8 **ptr;

	if (noreplace_smp)
		return;

	for (ptr = start; ptr < end; ptr++) {
		if (*ptr < text)
			continue;
@@ -219,6 +231,9 @@ void alternatives_smp_module_add(struct module *mod, char *name,
	struct smp_alt_module *smp;
	unsigned long flags;

	if (noreplace_smp)
		return;

	if (smp_alt_once) {
		if (boot_cpu_has(X86_FEATURE_UP))
			alternatives_smp_unlock(locks, locks_end,
@@ -253,7 +268,7 @@ void alternatives_smp_module_del(struct module *mod)
	struct smp_alt_module *item;
	unsigned long flags;

	if (smp_alt_once)
	if (smp_alt_once || noreplace_smp)
		return;

	spin_lock_irqsave(&smp_alt, flags);
@@ -284,7 +299,7 @@ void alternatives_smp_switch(int smp)
	return;
#endif

	if (smp_alt_once)
	if (noreplace_smp || smp_alt_once)
		return;
	BUG_ON(!smp && (num_online_cpus() > 1));