[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: Shaohua Li <shaohua.li@intel.com>
Acked-by: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/kernel/cpu/common.c b/arch/i386/kernel/cpu/common.c
index 2203a9d..4553ffd 100644
--- a/arch/i386/kernel/cpu/common.c
+++ b/arch/i386/kernel/cpu/common.c
@@ -435,6 +435,11 @@
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
diff --git a/arch/i386/kernel/cpu/mtrr/generic.c b/arch/i386/kernel/cpu/mtrr/generic.c
index 64d91f7..169ac8e 100644
--- a/arch/i386/kernel/cpu/mtrr/generic.c
+++ b/arch/i386/kernel/cpu/mtrr/generic.c
@@ -67,13 +67,6 @@
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 @@
*/
{
unsigned long flags;
+ struct mtrr_var_range *vr;
+
+ vr = &mtrr_state.var_ranges[reg];
local_irq_save(flags);
prepare_set();
@@ -342,11 +338,15 @@
/* 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();
diff --git a/arch/i386/kernel/cpu/mtrr/main.c b/arch/i386/kernel/cpu/mtrr/main.c
index d66b09e..764cac6 100644
--- a/arch/i386/kernel/cpu/mtrr/main.c
+++ b/arch/i386/kernel/cpu/mtrr/main.c
@@ -332,6 +332,8 @@
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 @@
error = i;
out:
up(&main_lock);
+ unlock_cpu_hotplug();
return error;
}
@@ -461,6 +464,8 @@
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 @@
error = reg;
out:
up(&main_lock);
+ unlock_cpu_hotplug();
return error;
}
/**
@@ -544,21 +550,9 @@
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 @@
/**
- * 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 @@
if (mtrr_if) {
set_num_var_ranges();
init_table();
- init_other_cpus();
-
- return sysdev_driver_register(&cpu_sysdev_class,
- &mtrr_sysdev_driver);
+ if (use_intel())
+ get_mtrr_state();
}
- return -ENXIO;
}
-subsys_initcall(mtrr_init);
+void mtrr_ap_init(void)
+{
+ unsigned long flags;
+
+ 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 0;
+}
+subsys_initcall(mtrr_init_finialize);
diff --git a/arch/i386/kernel/cpu/mtrr/mtrr.h b/arch/i386/kernel/cpu/mtrr/mtrr.h
index de13512..99c9f26 100644
--- a/arch/i386/kernel/cpu/mtrr/mtrr.h
+++ b/arch/i386/kernel/cpu/mtrr/mtrr.h
@@ -91,7 +91,6 @@
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);
