x86: apic - rearrange functions and comments
Rearrange functions and comments to find differences
easier.
Also use apic_printk in setup_boot_APIC_clock for
64bit mode.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c
index 13dea93..46523c0 100644
--- a/arch/x86/kernel/apic_64.c
+++ b/arch/x86/kernel/apic_64.c
@@ -81,6 +81,9 @@
static void lapic_timer_broadcast(cpumask_t mask);
static void apic_pm_activate(void);
+/*
+ * The local apic timer can be used for any function which is CPU local.
+ */
static struct clock_event_device lapic_clockevent = {
.name = "lapic",
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
@@ -127,6 +130,11 @@
return lapic_get_version() >= 0x14;
}
+/*
+ * Paravirt kernels also might be using these below ops. So we still
+ * use generic apic_read()/apic_write(), which might be pointing to different
+ * ops in PARAVIRT case.
+ */
void xapic_wait_icr_idle(void)
{
while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
@@ -175,7 +183,6 @@
};
struct apic_ops __read_mostly *apic_ops = &xapic_ops;
-
EXPORT_SYMBOL_GPL(apic_ops);
static void x2apic_wait_icr_idle(void)
@@ -244,6 +251,10 @@
return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2;
}
+/*
+ * Local APIC timer
+ */
+
/* Clock divisor is set to 1 */
#define APIC_DIVISOR 1
@@ -257,7 +268,6 @@
* We do reads before writes even if unnecessary, to get around the
* P5 APIC double write bug.
*/
-
static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
{
unsigned int lvtt_value, tmp_value;
@@ -474,10 +484,10 @@
void __init setup_boot_APIC_clock(void)
{
/*
- * The local apic timer can be disabled via the kernel commandline.
- * Register the lapic timer as a dummy clock event source on SMP
- * systems, so the broadcast mechanism is used. On UP systems simply
- * ignore it.
+ * The local apic timer can be disabled via the kernel
+ * commandline or from the CPU detection code. Register the lapic
+ * timer as a dummy clock event source on SMP systems, so the
+ * broadcast mechanism is used. On UP systems simply ignore it.
*/
if (disable_apic_timer) {
printk(KERN_INFO "Disabling APIC timer\n");
@@ -489,7 +499,9 @@
return;
}
- printk(KERN_INFO "Using local APIC timer interrupts.\n");
+ apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
+ "calibrating APIC timer ...\n");
+
if (calibrate_APIC_clock()) {
/* No broadcast on UP ! */
if (num_possible_cpus() > 1)
@@ -508,6 +520,7 @@
printk(KERN_WARNING "APIC timer registered as dummy,"
" due to nmi_watchdog=%d!\n", nmi_watchdog);
+ /* Setup the lapic or request the broadcast */
setup_APIC_timer();
}
@@ -577,6 +590,7 @@
irq_enter();
local_apic_timer_interrupt();
irq_exit();
+
set_irq_regs(old_regs);
}
@@ -1248,6 +1262,13 @@
enable_apic_mode();
}
+/**
+ * disconnect_bsp_APIC - detach the APIC from the interrupt system
+ * @virt_wire_setup: indicates, whether virtual wire mode is selected
+ *
+ * Virtual wire mode is necessary to deliver legacy interrupts even when the
+ * APIC is disabled.
+ */
void disconnect_bsp_APIC(int virt_wire_setup)
{
/* Go back to Virtual Wire compatibility mode */
@@ -1347,9 +1368,11 @@
#ifdef CONFIG_PM
static struct {
- /* 'active' is true if the local APIC was enabled by us and
- not the BIOS; this signifies that we are also responsible
- for disabling it before entering apm/acpi suspend */
+ /*
+ * 'active' is true if the local APIC was enabled by us and
+ * not the BIOS; this signifies that we are also responsible
+ * for disabling it before entering apm/acpi suspend
+ */
int active;
/* r/w apic fields */
unsigned int apic_id;
@@ -1458,6 +1481,11 @@
return 0;
}
+/*
+ * This device has no shutdown method - fully functioning local APICs
+ * are needed on every CPU up until machine_halt/restart/poweroff.
+ */
+
static struct sysdev_class lapic_sysclass = {
.name = "lapic",
.resume = lapic_resume,