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Diffstat (limited to 'arch/x86/kernel/hpet.c')
-rw-r--r--arch/x86/kernel/hpet.c77
1 files changed, 49 insertions, 28 deletions
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index dedc2bddf7a5..ba6e65884603 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -33,6 +33,7 @@
* HPET address is set in acpi/boot.c, when an ACPI entry exists
*/
unsigned long hpet_address;
+u8 hpet_blockid; /* OS timer block num */
#ifdef CONFIG_PCI_MSI
static unsigned long hpet_num_timers;
#endif
@@ -47,12 +48,12 @@ struct hpet_dev {
char name[10];
};
-unsigned long hpet_readl(unsigned long a)
+inline unsigned int hpet_readl(unsigned int a)
{
return readl(hpet_virt_address + a);
}
-static inline void hpet_writel(unsigned long d, unsigned long a)
+static inline void hpet_writel(unsigned int d, unsigned int a)
{
writel(d, hpet_virt_address + a);
}
@@ -167,7 +168,7 @@ do { \
static void hpet_reserve_msi_timers(struct hpet_data *hd);
-static void hpet_reserve_platform_timers(unsigned long id)
+static void hpet_reserve_platform_timers(unsigned int id)
{
struct hpet __iomem *hpet = hpet_virt_address;
struct hpet_timer __iomem *timer = &hpet->hpet_timers[2];
@@ -205,7 +206,7 @@ static void hpet_reserve_platform_timers(unsigned long id)
}
#else
-static void hpet_reserve_platform_timers(unsigned long id) { }
+static void hpet_reserve_platform_timers(unsigned int id) { }
#endif
/*
@@ -246,7 +247,7 @@ static void hpet_reset_counter(void)
static void hpet_start_counter(void)
{
- unsigned long cfg = hpet_readl(HPET_CFG);
+ unsigned int cfg = hpet_readl(HPET_CFG);
cfg |= HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
}
@@ -271,7 +272,7 @@ static void hpet_resume_counter(void)
static void hpet_enable_legacy_int(void)
{
- unsigned long cfg = hpet_readl(HPET_CFG);
+ unsigned int cfg = hpet_readl(HPET_CFG);
cfg |= HPET_CFG_LEGACY;
hpet_writel(cfg, HPET_CFG);
@@ -314,7 +315,7 @@ static int hpet_setup_msi_irq(unsigned int irq);
static void hpet_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt, int timer)
{
- unsigned long cfg, cmp, now;
+ unsigned int cfg, cmp, now;
uint64_t delta;
switch (mode) {
@@ -323,7 +324,7 @@ static void hpet_set_mode(enum clock_event_mode mode,
delta = ((uint64_t)(NSEC_PER_SEC/HZ)) * evt->mult;
delta >>= evt->shift;
now = hpet_readl(HPET_COUNTER);
- cmp = now + (unsigned long) delta;
+ cmp = now + (unsigned int) delta;
cfg = hpet_readl(HPET_Tn_CFG(timer));
/* Make sure we use edge triggered interrupts */
cfg &= ~HPET_TN_LEVEL;
@@ -339,7 +340,7 @@ static void hpet_set_mode(enum clock_event_mode mode,
* (See AMD-8111 HyperTransport I/O Hub Data Sheet,
* Publication # 24674)
*/
- hpet_writel((unsigned long) delta, HPET_Tn_CMP(timer));
+ hpet_writel((unsigned int) delta, HPET_Tn_CMP(timer));
hpet_start_counter();
hpet_print_config();
break;
@@ -383,13 +384,24 @@ static int hpet_next_event(unsigned long delta,
hpet_writel(cnt, HPET_Tn_CMP(timer));
/*
- * We need to read back the CMP register to make sure that
- * what we wrote hit the chip before we compare it to the
- * counter.
+ * We need to read back the CMP register on certain HPET
+ * implementations (ATI chipsets) which seem to delay the
+ * transfer of the compare register into the internal compare
+ * logic. With small deltas this might actually be too late as
+ * the counter could already be higher than the compare value
+ * at that point and we would wait for the next hpet interrupt
+ * forever. We found out that reading the CMP register back
+ * forces the transfer so we can rely on the comparison with
+ * the counter register below. If the read back from the
+ * compare register does not match the value we programmed
+ * then we might have a real hardware problem. We can not do
+ * much about it here, but at least alert the user/admin with
+ * a prominent warning.
*/
- WARN_ON_ONCE((u32)hpet_readl(HPET_Tn_CMP(timer)) != cnt);
+ WARN_ONCE(hpet_readl(HPET_Tn_CMP(timer)) != cnt,
+ KERN_WARNING "hpet: compare register read back failed.\n");
- return (s32)((u32)hpet_readl(HPET_COUNTER) - cnt) >= 0 ? -ETIME : 0;
+ return (s32)(hpet_readl(HPET_COUNTER) - cnt) >= 0 ? -ETIME : 0;
}
static void hpet_legacy_set_mode(enum clock_event_mode mode,
@@ -415,7 +427,7 @@ static struct hpet_dev *hpet_devs;
void hpet_msi_unmask(unsigned int irq)
{
struct hpet_dev *hdev = get_irq_data(irq);
- unsigned long cfg;
+ unsigned int cfg;
/* unmask it */
cfg = hpet_readl(HPET_Tn_CFG(hdev->num));
@@ -425,7 +437,7 @@ void hpet_msi_unmask(unsigned int irq)
void hpet_msi_mask(unsigned int irq)
{
- unsigned long cfg;
+ unsigned int cfg;
struct hpet_dev *hdev = get_irq_data(irq);
/* mask it */
@@ -467,7 +479,7 @@ static int hpet_msi_next_event(unsigned long delta,
static int hpet_setup_msi_irq(unsigned int irq)
{
- if (arch_setup_hpet_msi(irq)) {
+ if (arch_setup_hpet_msi(irq, hpet_blockid)) {
destroy_irq(irq);
return -EINVAL;
}
@@ -584,6 +596,8 @@ static void hpet_msi_capability_lookup(unsigned int start_timer)
unsigned int num_timers_used = 0;
int i;
+ if (boot_cpu_has(X86_FEATURE_ARAT))
+ return;
id = hpet_readl(HPET_ID);
num_timers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT);
@@ -598,7 +612,7 @@ static void hpet_msi_capability_lookup(unsigned int start_timer)
for (i = start_timer; i < num_timers - RESERVE_TIMERS; i++) {
struct hpet_dev *hdev = &hpet_devs[num_timers_used];
- unsigned long cfg = hpet_readl(HPET_Tn_CFG(i));
+ unsigned int cfg = hpet_readl(HPET_Tn_CFG(i));
/* Only consider HPET timer with MSI support */
if (!(cfg & HPET_TN_FSB_CAP))
@@ -813,7 +827,7 @@ static int hpet_clocksource_register(void)
*/
int __init hpet_enable(void)
{
- unsigned long id;
+ unsigned int id;
int i;
if (!is_hpet_capable())
@@ -872,10 +886,8 @@ int __init hpet_enable(void)
if (id & HPET_ID_LEGSUP) {
hpet_legacy_clockevent_register();
- hpet_msi_capability_lookup(2);
return 1;
}
- hpet_msi_capability_lookup(0);
return 0;
out_nohpet:
@@ -908,9 +920,17 @@ static __init int hpet_late_init(void)
if (!hpet_virt_address)
return -ENODEV;
+ if (hpet_readl(HPET_ID) & HPET_ID_LEGSUP)
+ hpet_msi_capability_lookup(2);
+ else
+ hpet_msi_capability_lookup(0);
+
hpet_reserve_platform_timers(hpet_readl(HPET_ID));
hpet_print_config();
+ if (boot_cpu_has(X86_FEATURE_ARAT))
+ return 0;
+
for_each_online_cpu(cpu) {
hpet_cpuhp_notify(NULL, CPU_ONLINE, (void *)(long)cpu);
}
@@ -925,7 +945,7 @@ fs_initcall(hpet_late_init);
void hpet_disable(void)
{
if (is_hpet_capable()) {
- unsigned long cfg = hpet_readl(HPET_CFG);
+ unsigned int cfg = hpet_readl(HPET_CFG);
if (hpet_legacy_int_enabled) {
cfg &= ~HPET_CFG_LEGACY;
@@ -965,8 +985,8 @@ static int hpet_prev_update_sec;
static struct rtc_time hpet_alarm_time;
static unsigned long hpet_pie_count;
static u32 hpet_t1_cmp;
-static unsigned long hpet_default_delta;
-static unsigned long hpet_pie_delta;
+static u32 hpet_default_delta;
+static u32 hpet_pie_delta;
static unsigned long hpet_pie_limit;
static rtc_irq_handler irq_handler;
@@ -1017,7 +1037,8 @@ EXPORT_SYMBOL_GPL(hpet_unregister_irq_handler);
*/
int hpet_rtc_timer_init(void)
{
- unsigned long cfg, cnt, delta, flags;
+ unsigned int cfg, cnt, delta;
+ unsigned long flags;
if (!is_hpet_enabled())
return 0;
@@ -1027,7 +1048,7 @@ int hpet_rtc_timer_init(void)
clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
clc >>= hpet_clockevent.shift + DEFAULT_RTC_SHIFT;
- hpet_default_delta = (unsigned long) clc;
+ hpet_default_delta = clc;
}
if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit)
@@ -1113,7 +1134,7 @@ int hpet_set_periodic_freq(unsigned long freq)
clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
do_div(clc, freq);
clc >>= hpet_clockevent.shift;
- hpet_pie_delta = (unsigned long) clc;
+ hpet_pie_delta = clc;
}
return 1;
}
@@ -1127,7 +1148,7 @@ EXPORT_SYMBOL_GPL(hpet_rtc_dropped_irq);
static void hpet_rtc_timer_reinit(void)
{
- unsigned long cfg, delta;
+ unsigned int cfg, delta;
int lost_ints = -1;
if (unlikely(!hpet_rtc_flags)) {
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.