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-rw-r--r--arch/x86/include/asm/hpet.h6
-rw-r--r--arch/x86/kernel/apic/msi.c4
-rw-r--r--arch/x86/kernel/hpet.c139
3 files changed, 64 insertions, 85 deletions
diff --git a/arch/x86/include/asm/hpet.h b/arch/x86/include/asm/hpet.h
index e3209f5de65d..6352dee37cda 100644
--- a/arch/x86/include/asm/hpet.h
+++ b/arch/x86/include/asm/hpet.h
@@ -75,15 +75,15 @@ extern unsigned int hpet_readl(unsigned int a);
extern void force_hpet_resume(void);
struct irq_data;
-struct hpet_dev;
+struct hpet_channel;
struct irq_domain;
extern void hpet_msi_unmask(struct irq_data *data);
extern void hpet_msi_mask(struct irq_data *data);
-extern void hpet_msi_write(struct hpet_dev *hdev, struct msi_msg *msg);
+extern void hpet_msi_write(struct hpet_channel *hc, struct msi_msg *msg);
extern struct irq_domain *hpet_create_irq_domain(int hpet_id);
extern int hpet_assign_irq(struct irq_domain *domain,
- struct hpet_dev *dev, int dev_num);
+ struct hpet_channel *hc, int dev_num);
#ifdef CONFIG_HPET_EMULATE_RTC
diff --git a/arch/x86/kernel/apic/msi.c b/arch/x86/kernel/apic/msi.c
index dad0dd759de2..7f7533462474 100644
--- a/arch/x86/kernel/apic/msi.c
+++ b/arch/x86/kernel/apic/msi.c
@@ -370,14 +370,14 @@ struct irq_domain *hpet_create_irq_domain(int hpet_id)
return d;
}
-int hpet_assign_irq(struct irq_domain *domain, struct hpet_dev *dev,
+int hpet_assign_irq(struct irq_domain *domain, struct hpet_channel *hc,
int dev_num)
{
struct irq_alloc_info info;
init_irq_alloc_info(&info, NULL);
info.type = X86_IRQ_ALLOC_TYPE_HPET;
- info.hpet_data = dev;
+ info.hpet_data = hc;
info.hpet_id = hpet_dev_id(domain);
info.hpet_index = dev_num;
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 32f21b429881..7f76f07138a6 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -13,15 +13,6 @@
#undef pr_fmt
#define pr_fmt(fmt) "hpet: " fmt
-struct hpet_dev {
- struct clock_event_device evt;
- unsigned int num;
- int cpu;
- unsigned int irq;
- unsigned int flags;
- char name[10];
-};
-
enum hpet_mode {
HPET_MODE_UNUSED,
HPET_MODE_LEGACY,
@@ -30,14 +21,19 @@ enum hpet_mode {
};
struct hpet_channel {
+ struct clock_event_device evt;
unsigned int num;
+ unsigned int cpu;
unsigned int irq;
enum hpet_mode mode;
+ unsigned int flags;
unsigned int boot_cfg;
+ char name[10];
};
struct hpet_base {
unsigned int nr_channels;
+ unsigned int nr_clockevents;
unsigned int boot_cfg;
struct hpet_channel *channels;
};
@@ -61,8 +57,7 @@ u8 hpet_blockid; /* OS timer block num */
bool hpet_msi_disable;
#ifdef CONFIG_PCI_MSI
-static struct hpet_dev *hpet_devs;
-static DEFINE_PER_CPU(struct hpet_dev *, cpu_hpet_dev);
+static DEFINE_PER_CPU(struct hpet_channel *, cpu_hpet_channel);
static struct irq_domain *hpet_domain;
#endif
@@ -79,9 +74,9 @@ static bool hpet_verbose;
static struct clock_event_device hpet_clockevent;
static inline
-struct hpet_dev *clockevent_to_channel(struct clock_event_device *evt)
+struct hpet_channel *clockevent_to_channel(struct clock_event_device *evt)
{
- return container_of(evt, struct hpet_dev, evt);
+ return container_of(evt, struct hpet_channel, evt);
}
inline unsigned int hpet_readl(unsigned int a)
@@ -460,10 +455,9 @@ static struct clock_event_device hpet_clockevent = {
void hpet_msi_unmask(struct irq_data *data)
{
- struct hpet_dev *hc = irq_data_get_irq_handler_data(data);
+ struct hpet_channel *hc = irq_data_get_irq_handler_data(data);
unsigned int cfg;
- /* unmask it */
cfg = hpet_readl(HPET_Tn_CFG(hc->num));
cfg |= HPET_TN_ENABLE | HPET_TN_FSB;
hpet_writel(cfg, HPET_Tn_CFG(hc->num));
@@ -471,16 +465,15 @@ void hpet_msi_unmask(struct irq_data *data)
void hpet_msi_mask(struct irq_data *data)
{
- struct hpet_dev *hc = irq_data_get_irq_handler_data(data);
+ struct hpet_channel *hc = irq_data_get_irq_handler_data(data);
unsigned int cfg;
- /* mask it */
cfg = hpet_readl(HPET_Tn_CFG(hc->num));
cfg &= ~(HPET_TN_ENABLE | HPET_TN_FSB);
hpet_writel(cfg, HPET_Tn_CFG(hc->num));
}
-void hpet_msi_write(struct hpet_dev *hc, struct msi_msg *msg)
+void hpet_msi_write(struct hpet_channel *hc, struct msi_msg *msg)
{
hpet_writel(msg->data, HPET_Tn_ROUTE(hc->num));
hpet_writel(msg->address_lo, HPET_Tn_ROUTE(hc->num) + 4);
@@ -503,7 +496,7 @@ static int hpet_msi_set_periodic(struct clock_event_device *evt)
static int hpet_msi_resume(struct clock_event_device *evt)
{
- struct hpet_dev *hc = clockevent_to_channel(evt);
+ struct hpet_channel *hc = clockevent_to_channel(evt);
struct irq_data *data = irq_get_irq_data(hc->irq);
struct msi_msg msg;
@@ -522,7 +515,7 @@ static int hpet_msi_next_event(unsigned long delta,
static irqreturn_t hpet_interrupt_handler(int irq, void *data)
{
- struct hpet_dev *hc = data;
+ struct hpet_channel *hc = data;
struct clock_event_device *evt = &hc->evt;
if (!evt->event_handler) {
@@ -534,24 +527,23 @@ static irqreturn_t hpet_interrupt_handler(int irq, void *data)
return IRQ_HANDLED;
}
-static int hpet_setup_irq(struct hpet_dev *dev)
+static int hpet_setup_irq(struct hpet_channel *hc)
{
-
- if (request_irq(dev->irq, hpet_interrupt_handler,
+ if (request_irq(hc->irq, hpet_interrupt_handler,
IRQF_TIMER | IRQF_NOBALANCING,
- dev->name, dev))
+ hc->name, hc))
return -1;
- disable_irq(dev->irq);
- irq_set_affinity(dev->irq, cpumask_of(dev->cpu));
- enable_irq(dev->irq);
+ disable_irq(hc->irq);
+ irq_set_affinity(hc->irq, cpumask_of(hc->cpu));
+ enable_irq(hc->irq);
- pr_debug("%s irq %d for MSI\n", dev->name, dev->irq);
+ pr_debug("%s irq %u for MSI\n", hc->name, hc->irq);
return 0;
}
-static void init_one_hpet_msi_clockevent(struct hpet_dev *hc, int cpu)
+static void init_one_hpet_msi_clockevent(struct hpet_channel *hc, int cpu)
{
struct clock_event_device *evt = &hc->evt;
@@ -559,7 +551,7 @@ static void init_one_hpet_msi_clockevent(struct hpet_dev *hc, int cpu)
return;
hc->cpu = cpu;
- per_cpu(cpu_hpet_dev, cpu) = hc;
+ per_cpu(cpu_hpet_channel, cpu) = hc;
evt->name = hc->name;
hpet_setup_irq(hc);
evt->irq = hc->irq;
@@ -581,15 +573,12 @@ static void init_one_hpet_msi_clockevent(struct hpet_dev *hc, int cpu)
0x7FFFFFFF);
}
-static struct hpet_dev *hpet_get_unused_timer(void)
+static struct hpet_channel *hpet_get_unused_clockevent(void)
{
int i;
- if (!hpet_devs)
- return NULL;
-
for (i = 0; i < hpet_base.nr_channels; i++) {
- struct hpet_dev *hc = &hpet_devs[i];
+ struct hpet_channel *hc = hpet_base.channels + i;
if (!(hc->flags & HPET_DEV_VALID))
continue;
@@ -603,7 +592,7 @@ static struct hpet_dev *hpet_get_unused_timer(void)
static int hpet_cpuhp_online(unsigned int cpu)
{
- struct hpet_dev *hc = hpet_get_unused_timer();
+ struct hpet_channel *hc = hpet_get_unused_clockevent();
if (hc)
init_one_hpet_msi_clockevent(hc, cpu);
@@ -612,59 +601,47 @@ static int hpet_cpuhp_online(unsigned int cpu)
static int hpet_cpuhp_dead(unsigned int cpu)
{
- struct hpet_dev *hc = per_cpu(cpu_hpet_dev, cpu);
+ struct hpet_channel *hc = per_cpu(cpu_hpet_channel, cpu);
if (!hc)
return 0;
free_irq(hc->irq, hc);
hc->flags &= ~HPET_DEV_USED;
- per_cpu(cpu_hpet_dev, cpu) = NULL;
+ per_cpu(cpu_hpet_channel, cpu) = NULL;
return 0;
}
-#ifdef CONFIG_HPET
-/* Reserve at least one timer for userspace (/dev/hpet) */
-#define RESERVE_TIMERS 1
-#else
-#define RESERVE_TIMERS 0
-#endif
-
-static void __init hpet_msi_capability_lookup(unsigned int start_timer)
+static void __init hpet_select_clockevents(void)
{
- unsigned int num_timers;
- unsigned int num_timers_used = 0;
- int i, irq;
+ unsigned int i;
- if (hpet_msi_disable)
- return;
+ hpet_base.nr_clockevents = 0;
- if (boot_cpu_has(X86_FEATURE_ARAT))
+ /* No point if MSI is disabled or CPU has an Always Runing APIC Timer */
+ if (hpet_msi_disable || boot_cpu_has(X86_FEATURE_ARAT))
return;
- num_timers = hpet_base.nr_channels;
hpet_print_config();
hpet_domain = hpet_create_irq_domain(hpet_blockid);
if (!hpet_domain)
return;
- hpet_devs = kcalloc(num_timers, sizeof(struct hpet_dev), GFP_KERNEL);
- if (!hpet_devs)
- return;
+ for (i = 0; i < hpet_base.nr_channels; i++) {
+ struct hpet_channel *hc = hpet_base.channels + i;
+ int irq;
- for (i = start_timer; i < num_timers - RESERVE_TIMERS; i++) {
- struct hpet_dev *hc = &hpet_devs[num_timers_used];
- unsigned int cfg = hpet_base.channels[i].boot_cfg;
+ if (hc->mode != HPET_MODE_UNUSED)
+ continue;
- /* Only consider HPET timer with MSI support */
- if (!(cfg & HPET_TN_FSB_CAP))
+ /* Only consider HPET channel with MSI support */
+ if (!(hc->boot_cfg & HPET_TN_FSB_CAP))
continue;
hc->flags = 0;
- if (cfg & HPET_TN_PERIODIC_CAP)
+ if (hc->boot_cfg & HPET_TN_PERIODIC_CAP)
hc->flags |= HPET_DEV_PERI_CAP;
sprintf(hc->name, "hpet%d", i);
- hc->num = i;
irq = hpet_assign_irq(hpet_domain, hc, hc->num);
if (irq <= 0)
@@ -673,13 +650,14 @@ static void __init hpet_msi_capability_lookup(unsigned int start_timer)
hc->irq = irq;
hc->flags |= HPET_DEV_FSB_CAP;
hc->flags |= HPET_DEV_VALID;
- num_timers_used++;
- if (num_timers_used == num_possible_cpus())
+ hc->mode = HPET_MODE_CLOCKEVT;
+
+ if (++hpet_base.nr_clockevents == num_possible_cpus())
break;
}
pr_info("%d channels of %d reserved for per-cpu timers\n",
- num_timers, num_timers_used);
+ hpet_base.nr_channels, hpet_base.nr_clockevents);
}
#ifdef CONFIG_HPET
@@ -687,11 +665,8 @@ static void __init hpet_reserve_msi_timers(struct hpet_data *hd)
{
int i;
- if (!hpet_devs)
- return;
-
for (i = 0; i < hpet_base.nr_channels; i++) {
- struct hpet_dev *hc = &hpet_devs[i];
+ struct hpet_channel *hc = hpet_base.channels + i;
if (!(hc->flags & HPET_DEV_VALID))
continue;
@@ -704,7 +679,7 @@ static void __init hpet_reserve_msi_timers(struct hpet_data *hd)
#else
-static inline void hpet_msi_capability_lookup(unsigned int start_timer) { }
+static inline void hpet_select_clockevents(void) { }
#ifdef CONFIG_HPET
static inline void hpet_reserve_msi_timers(struct hpet_data *hd) { }
@@ -991,6 +966,16 @@ out_nohpet:
/*
* The late initialization runs after the PCI quirks have been invoked
* which might have detected a system on which the HPET can be enforced.
+ *
+ * Also, the MSI machinery is not working yet when the HPET is initialized
+ * early.
+ *
+ * If the HPET is enabled, then:
+ *
+ * 1) Reserve one channel for /dev/hpet if CONFIG_HPET=y
+ * 2) Reserve up to num_possible_cpus() channels as per CPU clockevents
+ * 3) Setup /dev/hpet if CONFIG_HPET=y
+ * 4) Register hotplug callbacks when clockevents are available
*/
static __init int hpet_late_init(void)
{
@@ -1007,18 +992,12 @@ 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_select_device_channel();
+ hpet_select_clockevents();
hpet_reserve_platform_timers();
hpet_print_config();
- if (hpet_msi_disable)
- return 0;
-
- if (boot_cpu_has(X86_FEATURE_ARAT))
+ if (!hpet_base.nr_clockevents)
return 0;
ret = cpuhp_setup_state(CPUHP_AP_X86_HPET_ONLINE, "x86/hpet:online",
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