Commit 3b520b23 authored by Shaohua Li's avatar Shaohua Li Committed by Linus Torvalds
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[PATCH] MTRR suspend/resume cleanup 



There has been some discuss about solving the SMP MTRR suspend/resume
breakage, but I didn't find a patch for it.  This is an intent for it.  The
basic idea is moving mtrr initializing into cpu_identify for all APs (so it
works for cpu hotplug).  For BP, restore_processor_state is responsible for
restoring MTRR.

Signed-off-by: default avatarShaohua Li <shaohua.li@intel.com>
Acked-by: default avatarAndi Kleen <ak@muc.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 01d29936

arch/i386/kernel/cpu/common.c

+5 −0
Original line number Diff line number Diff line
@@ -435,6 +435,11 @@ void __devinit identify_cpu(struct cpuinfo_x86 *c) 
	if (c == &boot_cpu_data)

		sysenter_setup();

	enable_sep_cpu();



	if (c == &boot_cpu_data)

		mtrr_bp_init();

	else

		mtrr_ap_init();

}



#ifdef CONFIG_X86_HT

arch/i386/kernel/cpu/mtrr/generic.c

+11 −11
Original line number Diff line number Diff line
@@ -67,13 +67,6 @@ void __init get_mtrr_state(void) 
	mtrr_state.enabled = (lo & 0xc00) >> 10;

}



/*  Free resources associated with a struct mtrr_state  */

void __init finalize_mtrr_state(void)

{

	kfree(mtrr_state.var_ranges);

	mtrr_state.var_ranges = NULL;

}



/*  Some BIOS's are fucked and don't set all MTRRs the same!  */

void __init mtrr_state_warn(void)

{
@@ -334,6 +327,9 @@ static void generic_set_mtrr(unsigned int reg, unsigned long base, 
*/

{

	unsigned long flags;

	struct mtrr_var_range *vr;



	vr = &mtrr_state.var_ranges[reg];



	local_irq_save(flags);

	prepare_set();
@@ -342,11 +338,15 @@ static void generic_set_mtrr(unsigned int reg, unsigned long base, 
		/* The invalid bit is kept in the mask, so we simply clear the

		   relevant mask register to disable a range. */

		mtrr_wrmsr(MTRRphysMask_MSR(reg), 0, 0);

		memset(vr, 0, sizeof(struct mtrr_var_range));

	} else {

		mtrr_wrmsr(MTRRphysBase_MSR(reg), base << PAGE_SHIFT | type,

		      (base & size_and_mask) >> (32 - PAGE_SHIFT));

		mtrr_wrmsr(MTRRphysMask_MSR(reg), -size << PAGE_SHIFT | 0x800,

		      (-size & size_and_mask) >> (32 - PAGE_SHIFT));

		vr->base_lo = base << PAGE_SHIFT | type;

		vr->base_hi = (base & size_and_mask) >> (32 - PAGE_SHIFT);

		vr->mask_lo = -size << PAGE_SHIFT | 0x800;

		vr->mask_hi = (-size & size_and_mask) >> (32 - PAGE_SHIFT);



		mtrr_wrmsr(MTRRphysBase_MSR(reg), vr->base_lo, vr->base_hi);

		mtrr_wrmsr(MTRRphysMask_MSR(reg), vr->mask_lo, vr->mask_hi);

	}



	post_set();

arch/i386/kernel/cpu/mtrr/main.c

+53 −23
Original line number Diff line number Diff line
@@ -332,6 +332,8 @@ int mtrr_add_page(unsigned long base, unsigned long size, 


	error = -EINVAL;



	/* No CPU hotplug when we change MTRR entries */

	lock_cpu_hotplug();

	/*  Search for existing MTRR  */

	down(&main_lock);

	for (i = 0; i < num_var_ranges; ++i) {
@@ -372,6 +374,7 @@ int mtrr_add_page(unsigned long base, unsigned long size, 
	error = i;

 out:

	up(&main_lock);

	unlock_cpu_hotplug();

	return error;

}
@@ -461,6 +464,8 @@ int mtrr_del_page(int reg, unsigned long base, unsigned long size) 
		return -ENXIO;



	max = num_var_ranges;

	/* No CPU hotplug when we change MTRR entries */

	lock_cpu_hotplug();

	down(&main_lock);

	if (reg < 0) {

		/*  Search for existing MTRR  */
@@ -501,6 +506,7 @@ int mtrr_del_page(int reg, unsigned long base, unsigned long size) 
	error = reg;

 out:

	up(&main_lock);

	unlock_cpu_hotplug();

	return error;

}

/**
@@ -544,21 +550,9 @@ static void __init init_ifs(void) 
	centaur_init_mtrr();

}



static void __init init_other_cpus(void)

{

	if (use_intel())

		get_mtrr_state();



	/* bring up the other processors */

	set_mtrr(~0U,0,0,0);



	if (use_intel()) {

		finalize_mtrr_state();

		mtrr_state_warn();

	}

}





/* The suspend/resume methods are only for CPU without MTRR. CPU using generic

 * MTRR driver doesn't require this

 */

struct mtrr_value {

	mtrr_type	ltype;

	unsigned long	lbase;
@@ -611,13 +605,13 @@ static struct sysdev_driver mtrr_sysdev_driver = { 




/**

 * mtrr_init - initialize mtrrs on the boot CPU

 * mtrr_bp_init - initialize mtrrs on the boot CPU

 *

 * This needs to be called early; before any of the other CPUs are 

 * initialized (i.e. before smp_init()).

 * 

 */

static int __init mtrr_init(void)

void __init mtrr_bp_init(void)

{

	init_ifs();
@@ -674,12 +668,48 @@ static int __init mtrr_init(void) 
	if (mtrr_if) {

		set_num_var_ranges();

		init_table();

		init_other_cpus();

		if (use_intel())

			get_mtrr_state();

	}

}



void mtrr_ap_init(void)

{

	unsigned long flags;



		return sysdev_driver_register(&cpu_sysdev_class,

	if (!mtrr_if || !use_intel())

		return;

	/*

	 * Ideally we should hold main_lock here to avoid mtrr entries changed,

	 * but this routine will be called in cpu boot time, holding the lock

	 * breaks it. This routine is called in two cases: 1.very earily time

	 * of software resume, when there absolutely isn't mtrr entry changes;

	 * 2.cpu hotadd time. We let mtrr_add/del_page hold cpuhotplug lock to

	 * prevent mtrr entry changes

	 */

	local_irq_save(flags);



	mtrr_if->set_all();



	local_irq_restore(flags);

}



static int __init mtrr_init_finialize(void)

{

	if (!mtrr_if)

		return 0;

	if (use_intel())

		mtrr_state_warn();

	else {

		/* The CPUs haven't MTRR and seemes not support SMP. They have

		 * specific drivers, we use a tricky method to support

		 * suspend/resume for them.

		 * TBD: is there any system with such CPU which supports

		 * suspend/resume?  if no, we should remove the code.

		 */

		sysdev_driver_register(&cpu_sysdev_class,

			&mtrr_sysdev_driver);

	}

	return -ENXIO;

	return 0;

}



subsys_initcall(mtrr_init);
 
subsys_initcall(mtrr_init_finialize);

arch/i386/kernel/cpu/mtrr/mtrr.h

+0 −1
Original line number Diff line number Diff line
@@ -91,7 +91,6 @@ extern struct mtrr_ops * mtrr_if; 


extern unsigned int num_var_ranges;



void finalize_mtrr_state(void);

void mtrr_state_warn(void);

char *mtrr_attrib_to_str(int x);

void mtrr_wrmsr(unsigned, unsigned, unsigned);

arch/i386/power/cpu.c

+1 −0
Original line number Diff line number Diff line
@@ -137,6 +137,7 @@ void __restore_processor_state(struct saved_context *ctxt) 


	fix_processor_context();

	do_fpu_end();

	mtrr_ap_init();

}



void restore_processor_state(void)

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