From 37f49e37ab4cb5d0bc4c60eb5c6d4dd57db767bb Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 10 May 2024 07:44:59 +0000
Subject: [PATCH] gmac get mac form eeprom
---
kernel/arch/x86/kernel/hpet.c | 1041 ++++++++++++++++++++++++++++-----------------------------
1 files changed, 518 insertions(+), 523 deletions(-)
diff --git a/kernel/arch/x86/kernel/hpet.c b/kernel/arch/x86/kernel/hpet.c
index 1e3f1f1..574df24 100644
--- a/kernel/arch/x86/kernel/hpet.c
+++ b/kernel/arch/x86/kernel/hpet.c
@@ -1,35 +1,45 @@
-#include <linux/clocksource.h>
+// SPDX-License-Identifier: GPL-2.0-only
#include <linux/clockchips.h>
#include <linux/interrupt.h>
-#include <linux/irq.h>
#include <linux/export.h>
#include <linux/delay.h>
-#include <linux/errno.h>
-#include <linux/i8253.h>
-#include <linux/slab.h>
#include <linux/hpet.h>
-#include <linux/init.h>
#include <linux/cpu.h>
-#include <linux/pm.h>
-#include <linux/io.h>
+#include <linux/irq.h>
-#include <asm/cpufeature.h>
-#include <asm/irqdomain.h>
-#include <asm/fixmap.h>
#include <asm/hpet.h>
#include <asm/time.h>
+#include <asm/mwait.h>
+
+#undef pr_fmt
+#define pr_fmt(fmt) "hpet: " fmt
+
+enum hpet_mode {
+ HPET_MODE_UNUSED,
+ HPET_MODE_LEGACY,
+ HPET_MODE_CLOCKEVT,
+ HPET_MODE_DEVICE,
+};
+
+struct hpet_channel {
+ struct clock_event_device evt;
+ unsigned int num;
+ unsigned int cpu;
+ unsigned int irq;
+ unsigned int in_use;
+ enum hpet_mode mode;
+ 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;
+};
#define HPET_MASK CLOCKSOURCE_MASK(32)
-
-/* FSEC = 10^-15
- NSEC = 10^-9 */
-#define FSEC_PER_NSEC 1000000L
-
-#define HPET_DEV_USED_BIT 2
-#define HPET_DEV_USED (1 << HPET_DEV_USED_BIT)
-#define HPET_DEV_VALID 0x8
-#define HPET_DEV_FSB_CAP 0x1000
-#define HPET_DEV_PERI_CAP 0x2000
#define HPET_MIN_CYCLES 128
#define HPET_MIN_PROG_DELTA (HPET_MIN_CYCLES + (HPET_MIN_CYCLES >> 1))
@@ -42,22 +52,25 @@
bool hpet_msi_disable;
#ifdef CONFIG_PCI_MSI
-static unsigned int hpet_num_timers;
+static DEFINE_PER_CPU(struct hpet_channel *, cpu_hpet_channel);
+static struct irq_domain *hpet_domain;
#endif
+
static void __iomem *hpet_virt_address;
-struct hpet_dev {
- struct clock_event_device evt;
- unsigned int num;
- int cpu;
- unsigned int irq;
- unsigned int flags;
- char name[10];
-};
+static struct hpet_base hpet_base;
-static inline struct hpet_dev *EVT_TO_HPET_DEV(struct clock_event_device *evtdev)
+static bool hpet_legacy_int_enabled;
+static unsigned long hpet_freq;
+
+bool boot_hpet_disable;
+bool hpet_force_user;
+static bool hpet_verbose;
+
+static inline
+struct hpet_channel *clockevent_to_channel(struct clock_event_device *evt)
{
- return container_of(evtdev, struct hpet_dev, evt);
+ return container_of(evt, struct hpet_channel, evt);
}
inline unsigned int hpet_readl(unsigned int a)
@@ -70,13 +83,9 @@
writel(d, hpet_virt_address + a);
}
-#ifdef CONFIG_X86_64
-#include <asm/pgtable.h>
-#endif
-
static inline void hpet_set_mapping(void)
{
- hpet_virt_address = ioremap_nocache(hpet_address, HPET_MMAP_SIZE);
+ hpet_virt_address = ioremap(hpet_address, HPET_MMAP_SIZE);
}
static inline void hpet_clear_mapping(void)
@@ -88,10 +97,6 @@
/*
* HPET command line enable / disable
*/
-bool boot_hpet_disable;
-bool hpet_force_user;
-static bool hpet_verbose;
-
static int __init hpet_setup(char *str)
{
while (str) {
@@ -123,13 +128,8 @@
return !boot_hpet_disable && hpet_address;
}
-/*
- * HPET timer interrupt enable / disable
- */
-static bool hpet_legacy_int_enabled;
-
/**
- * is_hpet_enabled - check whether the hpet timer interrupt is enabled
+ * is_hpet_enabled - Check whether the legacy HPET timer interrupt is enabled
*/
int is_hpet_enabled(void)
{
@@ -139,32 +139,36 @@
static void _hpet_print_config(const char *function, int line)
{
- u32 i, timers, l, h;
- printk(KERN_INFO "hpet: %s(%d):\n", function, line);
- l = hpet_readl(HPET_ID);
- h = hpet_readl(HPET_PERIOD);
- timers = ((l & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
- printk(KERN_INFO "hpet: ID: 0x%x, PERIOD: 0x%x\n", l, h);
- l = hpet_readl(HPET_CFG);
- h = hpet_readl(HPET_STATUS);
- printk(KERN_INFO "hpet: CFG: 0x%x, STATUS: 0x%x\n", l, h);
+ u32 i, id, period, cfg, status, channels, l, h;
+
+ pr_info("%s(%d):\n", function, line);
+
+ id = hpet_readl(HPET_ID);
+ period = hpet_readl(HPET_PERIOD);
+ pr_info("ID: 0x%x, PERIOD: 0x%x\n", id, period);
+
+ cfg = hpet_readl(HPET_CFG);
+ status = hpet_readl(HPET_STATUS);
+ pr_info("CFG: 0x%x, STATUS: 0x%x\n", cfg, status);
+
l = hpet_readl(HPET_COUNTER);
h = hpet_readl(HPET_COUNTER+4);
- printk(KERN_INFO "hpet: COUNTER_l: 0x%x, COUNTER_h: 0x%x\n", l, h);
+ pr_info("COUNTER_l: 0x%x, COUNTER_h: 0x%x\n", l, h);
- for (i = 0; i < timers; i++) {
+ channels = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
+
+ for (i = 0; i < channels; i++) {
l = hpet_readl(HPET_Tn_CFG(i));
h = hpet_readl(HPET_Tn_CFG(i)+4);
- printk(KERN_INFO "hpet: T%d: CFG_l: 0x%x, CFG_h: 0x%x\n",
- i, l, h);
+ pr_info("T%d: CFG_l: 0x%x, CFG_h: 0x%x\n", i, l, h);
+
l = hpet_readl(HPET_Tn_CMP(i));
h = hpet_readl(HPET_Tn_CMP(i)+4);
- printk(KERN_INFO "hpet: T%d: CMP_l: 0x%x, CMP_h: 0x%x\n",
- i, l, h);
+ pr_info("T%d: CMP_l: 0x%x, CMP_h: 0x%x\n", i, l, h);
+
l = hpet_readl(HPET_Tn_ROUTE(i));
h = hpet_readl(HPET_Tn_ROUTE(i)+4);
- printk(KERN_INFO "hpet: T%d ROUTE_l: 0x%x, ROUTE_h: 0x%x\n",
- i, l, h);
+ pr_info("T%d ROUTE_l: 0x%x, ROUTE_h: 0x%x\n", i, l, h);
}
}
@@ -175,31 +179,20 @@
} while (0)
/*
- * When the hpet driver (/dev/hpet) is enabled, we need to reserve
+ * When the HPET driver (/dev/hpet) is enabled, we need to reserve
* timer 0 and timer 1 in case of RTC emulation.
*/
#ifdef CONFIG_HPET
-static void hpet_reserve_msi_timers(struct hpet_data *hd);
-
-static void hpet_reserve_platform_timers(unsigned int id)
+static void __init hpet_reserve_platform_timers(void)
{
- struct hpet __iomem *hpet = hpet_virt_address;
- struct hpet_timer __iomem *timer = &hpet->hpet_timers[2];
- unsigned int nrtimers, i;
struct hpet_data hd;
-
- nrtimers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
+ unsigned int i;
memset(&hd, 0, sizeof(hd));
hd.hd_phys_address = hpet_address;
- hd.hd_address = hpet;
- hd.hd_nirqs = nrtimers;
- hpet_reserve_timer(&hd, 0);
-
-#ifdef CONFIG_HPET_EMULATE_RTC
- hpet_reserve_timer(&hd, 1);
-#endif
+ hd.hd_address = hpet_virt_address;
+ hd.hd_nirqs = hpet_base.nr_channels;
/*
* NOTE that hd_irq[] reflects IOAPIC input pins (LEGACY_8254
@@ -209,30 +202,52 @@
hd.hd_irq[0] = HPET_LEGACY_8254;
hd.hd_irq[1] = HPET_LEGACY_RTC;
- for (i = 2; i < nrtimers; timer++, i++) {
- hd.hd_irq[i] = (readl(&timer->hpet_config) &
- Tn_INT_ROUTE_CNF_MASK) >> Tn_INT_ROUTE_CNF_SHIFT;
+ for (i = 0; i < hpet_base.nr_channels; i++) {
+ struct hpet_channel *hc = hpet_base.channels + i;
+
+ if (i >= 2)
+ hd.hd_irq[i] = hc->irq;
+
+ switch (hc->mode) {
+ case HPET_MODE_UNUSED:
+ case HPET_MODE_DEVICE:
+ hc->mode = HPET_MODE_DEVICE;
+ break;
+ case HPET_MODE_CLOCKEVT:
+ case HPET_MODE_LEGACY:
+ hpet_reserve_timer(&hd, hc->num);
+ break;
+ }
}
- hpet_reserve_msi_timers(&hd);
-
hpet_alloc(&hd);
-
}
+
+static void __init hpet_select_device_channel(void)
+{
+ int i;
+
+ for (i = 0; i < hpet_base.nr_channels; i++) {
+ struct hpet_channel *hc = hpet_base.channels + i;
+
+ /* Associate the first unused channel to /dev/hpet */
+ if (hc->mode == HPET_MODE_UNUSED) {
+ hc->mode = HPET_MODE_DEVICE;
+ return;
+ }
+ }
+}
+
#else
-static void hpet_reserve_platform_timers(unsigned int id) { }
+static inline void hpet_reserve_platform_timers(void) { }
+static inline void hpet_select_device_channel(void) {}
#endif
-/*
- * Common hpet info
- */
-static unsigned long hpet_freq;
-
-static struct clock_event_device hpet_clockevent;
-
+/* Common HPET functions */
static void hpet_stop_counter(void)
{
u32 cfg = hpet_readl(HPET_CFG);
+
cfg &= ~HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
}
@@ -246,6 +261,7 @@
static void hpet_start_counter(void)
{
unsigned int cfg = hpet_readl(HPET_CFG);
+
cfg |= HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
}
@@ -277,24 +293,9 @@
hpet_legacy_int_enabled = true;
}
-static void hpet_legacy_clockevent_register(void)
+static int hpet_clkevt_set_state_periodic(struct clock_event_device *evt)
{
- /* Start HPET legacy interrupts */
- hpet_enable_legacy_int();
-
- /*
- * Start hpet with the boot cpu mask and make it
- * global after the IO_APIC has been initialized.
- */
- hpet_clockevent.cpumask = cpumask_of(boot_cpu_data.cpu_index);
- clockevents_config_and_register(&hpet_clockevent, hpet_freq,
- HPET_MIN_PROG_DELTA, 0x7FFFFFFF);
- global_clock_event = &hpet_clockevent;
- printk(KERN_DEBUG "hpet clockevent registered\n");
-}
-
-static int hpet_set_periodic(struct clock_event_device *evt, int timer)
-{
+ unsigned int channel = clockevent_to_channel(evt)->num;
unsigned int cfg, cmp, now;
uint64_t delta;
@@ -303,11 +304,11 @@
delta >>= evt->shift;
now = hpet_readl(HPET_COUNTER);
cmp = now + (unsigned int)delta;
- cfg = hpet_readl(HPET_Tn_CFG(timer));
+ cfg = hpet_readl(HPET_Tn_CFG(channel));
cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC | HPET_TN_SETVAL |
HPET_TN_32BIT;
- hpet_writel(cfg, HPET_Tn_CFG(timer));
- hpet_writel(cmp, HPET_Tn_CMP(timer));
+ hpet_writel(cfg, HPET_Tn_CFG(channel));
+ hpet_writel(cmp, HPET_Tn_CMP(channel));
udelay(1);
/*
* HPET on AMD 81xx needs a second write (with HPET_TN_SETVAL
@@ -316,52 +317,55 @@
* (See AMD-8111 HyperTransport I/O Hub Data Sheet,
* Publication # 24674)
*/
- hpet_writel((unsigned int)delta, HPET_Tn_CMP(timer));
+ hpet_writel((unsigned int)delta, HPET_Tn_CMP(channel));
hpet_start_counter();
hpet_print_config();
return 0;
}
-static int hpet_set_oneshot(struct clock_event_device *evt, int timer)
+static int hpet_clkevt_set_state_oneshot(struct clock_event_device *evt)
{
+ unsigned int channel = clockevent_to_channel(evt)->num;
unsigned int cfg;
- cfg = hpet_readl(HPET_Tn_CFG(timer));
+ cfg = hpet_readl(HPET_Tn_CFG(channel));
cfg &= ~HPET_TN_PERIODIC;
cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
- hpet_writel(cfg, HPET_Tn_CFG(timer));
+ hpet_writel(cfg, HPET_Tn_CFG(channel));
return 0;
}
-static int hpet_shutdown(struct clock_event_device *evt, int timer)
+static int hpet_clkevt_set_state_shutdown(struct clock_event_device *evt)
{
+ unsigned int channel = clockevent_to_channel(evt)->num;
unsigned int cfg;
- cfg = hpet_readl(HPET_Tn_CFG(timer));
+ cfg = hpet_readl(HPET_Tn_CFG(channel));
cfg &= ~HPET_TN_ENABLE;
- hpet_writel(cfg, HPET_Tn_CFG(timer));
+ hpet_writel(cfg, HPET_Tn_CFG(channel));
return 0;
}
-static int hpet_resume(struct clock_event_device *evt)
+static int hpet_clkevt_legacy_resume(struct clock_event_device *evt)
{
hpet_enable_legacy_int();
hpet_print_config();
return 0;
}
-static int hpet_next_event(unsigned long delta,
- struct clock_event_device *evt, int timer)
+static int
+hpet_clkevt_set_next_event(unsigned long delta, struct clock_event_device *evt)
{
+ unsigned int channel = clockevent_to_channel(evt)->num;
u32 cnt;
s32 res;
cnt = hpet_readl(HPET_COUNTER);
cnt += (u32) delta;
- hpet_writel(cnt, HPET_Tn_CMP(timer));
+ hpet_writel(cnt, HPET_Tn_CMP(channel));
/*
* HPETs are a complete disaster. The compare register is
@@ -390,360 +394,250 @@
return res < HPET_MIN_CYCLES ? -ETIME : 0;
}
-static int hpet_legacy_shutdown(struct clock_event_device *evt)
+static void hpet_init_clockevent(struct hpet_channel *hc, unsigned int rating)
{
- return hpet_shutdown(evt, 0);
+ struct clock_event_device *evt = &hc->evt;
+
+ evt->rating = rating;
+ evt->irq = hc->irq;
+ evt->name = hc->name;
+ evt->cpumask = cpumask_of(hc->cpu);
+ evt->set_state_oneshot = hpet_clkevt_set_state_oneshot;
+ evt->set_next_event = hpet_clkevt_set_next_event;
+ evt->set_state_shutdown = hpet_clkevt_set_state_shutdown;
+
+ evt->features = CLOCK_EVT_FEAT_ONESHOT;
+ if (hc->boot_cfg & HPET_TN_PERIODIC) {
+ evt->features |= CLOCK_EVT_FEAT_PERIODIC;
+ evt->set_state_periodic = hpet_clkevt_set_state_periodic;
+ }
}
-static int hpet_legacy_set_oneshot(struct clock_event_device *evt)
+static void __init hpet_legacy_clockevent_register(struct hpet_channel *hc)
{
- return hpet_set_oneshot(evt, 0);
-}
+ /*
+ * Start HPET with the boot CPU's cpumask and make it global after
+ * the IO_APIC has been initialized.
+ */
+ hc->cpu = boot_cpu_data.cpu_index;
+ strncpy(hc->name, "hpet", sizeof(hc->name));
+ hpet_init_clockevent(hc, 50);
-static int hpet_legacy_set_periodic(struct clock_event_device *evt)
-{
- return hpet_set_periodic(evt, 0);
-}
+ hc->evt.tick_resume = hpet_clkevt_legacy_resume;
-static int hpet_legacy_resume(struct clock_event_device *evt)
-{
- return hpet_resume(evt);
-}
+ /*
+ * Legacy horrors and sins from the past. HPET used periodic mode
+ * unconditionally forever on the legacy channel 0. Removing the
+ * below hack and using the conditional in hpet_init_clockevent()
+ * makes at least Qemu and one hardware machine fail to boot.
+ * There are two issues which cause the boot failure:
+ *
+ * #1 After the timer delivery test in IOAPIC and the IOAPIC setup
+ * the next interrupt is not delivered despite the HPET channel
+ * being programmed correctly. Reprogramming the HPET after
+ * switching to IOAPIC makes it work again. After fixing this,
+ * the next issue surfaces:
+ *
+ * #2 Due to the unconditional periodic mode availability the Local
+ * APIC timer calibration can hijack the global clockevents
+ * event handler without causing damage. Using oneshot at this
+ * stage makes if hang because the HPET does not get
+ * reprogrammed due to the handler hijacking. Duh, stupid me!
+ *
+ * Both issues require major surgery and especially the kick HPET
+ * again after enabling IOAPIC results in really nasty hackery.
+ * This 'assume periodic works' magic has survived since HPET
+ * support got added, so it's questionable whether this should be
+ * fixed. Both Qemu and the failing hardware machine support
+ * periodic mode despite the fact that both don't advertise it in
+ * the configuration register and both need that extra kick after
+ * switching to IOAPIC. Seems to be a feature...
+ */
+ hc->evt.features |= CLOCK_EVT_FEAT_PERIODIC;
+ hc->evt.set_state_periodic = hpet_clkevt_set_state_periodic;
-static int hpet_legacy_next_event(unsigned long delta,
- struct clock_event_device *evt)
-{
- return hpet_next_event(delta, evt, 0);
-}
+ /* Start HPET legacy interrupts */
+ hpet_enable_legacy_int();
-/*
- * The hpet clock event device
- */
-static struct clock_event_device hpet_clockevent = {
- .name = "hpet",
- .features = CLOCK_EVT_FEAT_PERIODIC |
- CLOCK_EVT_FEAT_ONESHOT,
- .set_state_periodic = hpet_legacy_set_periodic,
- .set_state_oneshot = hpet_legacy_set_oneshot,
- .set_state_shutdown = hpet_legacy_shutdown,
- .tick_resume = hpet_legacy_resume,
- .set_next_event = hpet_legacy_next_event,
- .irq = 0,
- .rating = 50,
-};
+ clockevents_config_and_register(&hc->evt, hpet_freq,
+ HPET_MIN_PROG_DELTA, 0x7FFFFFFF);
+ global_clock_event = &hc->evt;
+ pr_debug("Clockevent registered\n");
+}
/*
* HPET MSI Support
*/
#ifdef CONFIG_PCI_MSI
-static DEFINE_PER_CPU(struct hpet_dev *, cpu_hpet_dev);
-static struct hpet_dev *hpet_devs;
-static struct irq_domain *hpet_domain;
-
void hpet_msi_unmask(struct irq_data *data)
{
- struct hpet_dev *hdev = 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(hdev->num));
+ cfg = hpet_readl(HPET_Tn_CFG(hc->num));
cfg |= HPET_TN_ENABLE | HPET_TN_FSB;
- hpet_writel(cfg, HPET_Tn_CFG(hdev->num));
+ hpet_writel(cfg, HPET_Tn_CFG(hc->num));
}
void hpet_msi_mask(struct irq_data *data)
{
- struct hpet_dev *hdev = 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(hdev->num));
+ cfg = hpet_readl(HPET_Tn_CFG(hc->num));
cfg &= ~(HPET_TN_ENABLE | HPET_TN_FSB);
- hpet_writel(cfg, HPET_Tn_CFG(hdev->num));
+ hpet_writel(cfg, HPET_Tn_CFG(hc->num));
}
-void hpet_msi_write(struct hpet_dev *hdev, struct msi_msg *msg)
+void hpet_msi_write(struct hpet_channel *hc, struct msi_msg *msg)
{
- hpet_writel(msg->data, HPET_Tn_ROUTE(hdev->num));
- hpet_writel(msg->address_lo, HPET_Tn_ROUTE(hdev->num) + 4);
+ hpet_writel(msg->data, HPET_Tn_ROUTE(hc->num));
+ hpet_writel(msg->address_lo, HPET_Tn_ROUTE(hc->num) + 4);
}
-void hpet_msi_read(struct hpet_dev *hdev, struct msi_msg *msg)
+static int hpet_clkevt_msi_resume(struct clock_event_device *evt)
{
- msg->data = hpet_readl(HPET_Tn_ROUTE(hdev->num));
- msg->address_lo = hpet_readl(HPET_Tn_ROUTE(hdev->num) + 4);
- msg->address_hi = 0;
-}
-
-static int hpet_msi_shutdown(struct clock_event_device *evt)
-{
- struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
-
- return hpet_shutdown(evt, hdev->num);
-}
-
-static int hpet_msi_set_oneshot(struct clock_event_device *evt)
-{
- struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
-
- return hpet_set_oneshot(evt, hdev->num);
-}
-
-static int hpet_msi_set_periodic(struct clock_event_device *evt)
-{
- struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
-
- return hpet_set_periodic(evt, hdev->num);
-}
-
-static int hpet_msi_resume(struct clock_event_device *evt)
-{
- struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
- struct irq_data *data = irq_get_irq_data(hdev->irq);
+ struct hpet_channel *hc = clockevent_to_channel(evt);
+ struct irq_data *data = irq_get_irq_data(hc->irq);
struct msi_msg msg;
/* Restore the MSI msg and unmask the interrupt */
irq_chip_compose_msi_msg(data, &msg);
- hpet_msi_write(hdev, &msg);
+ hpet_msi_write(hc, &msg);
hpet_msi_unmask(data);
return 0;
}
-static int hpet_msi_next_event(unsigned long delta,
- struct clock_event_device *evt)
+static irqreturn_t hpet_msi_interrupt_handler(int irq, void *data)
{
- struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
- return hpet_next_event(delta, evt, hdev->num);
-}
+ struct hpet_channel *hc = data;
+ struct clock_event_device *evt = &hc->evt;
-static irqreturn_t hpet_interrupt_handler(int irq, void *data)
-{
- struct hpet_dev *dev = (struct hpet_dev *)data;
- struct clock_event_device *hevt = &dev->evt;
-
- if (!hevt->event_handler) {
- printk(KERN_INFO "Spurious HPET timer interrupt on HPET timer %d\n",
- dev->num);
+ if (!evt->event_handler) {
+ pr_info("Spurious interrupt HPET channel %d\n", hc->num);
return IRQ_HANDLED;
}
- hevt->event_handler(hevt);
+ evt->event_handler(evt);
return IRQ_HANDLED;
}
-static int hpet_setup_irq(struct hpet_dev *dev)
+static int hpet_setup_msi_irq(struct hpet_channel *hc)
{
-
- if (request_irq(dev->irq, hpet_interrupt_handler,
+ if (request_irq(hc->irq, hpet_msi_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);
- printk(KERN_DEBUG "hpet: %s irq %d for MSI\n",
- dev->name, dev->irq);
+ pr_debug("%s irq %u for MSI\n", hc->name, hc->irq);
return 0;
}
-/* This should be called in specific @cpu */
-static void init_one_hpet_msi_clockevent(struct hpet_dev *hdev, int cpu)
+/* Invoked from the hotplug callback on @cpu */
+static void init_one_hpet_msi_clockevent(struct hpet_channel *hc, int cpu)
{
- struct clock_event_device *evt = &hdev->evt;
+ struct clock_event_device *evt = &hc->evt;
- WARN_ON(cpu != smp_processor_id());
- if (!(hdev->flags & HPET_DEV_VALID))
- return;
+ hc->cpu = cpu;
+ per_cpu(cpu_hpet_channel, cpu) = hc;
+ hpet_setup_msi_irq(hc);
- hdev->cpu = cpu;
- per_cpu(cpu_hpet_dev, cpu) = hdev;
- evt->name = hdev->name;
- hpet_setup_irq(hdev);
- evt->irq = hdev->irq;
-
- evt->rating = 110;
- evt->features = CLOCK_EVT_FEAT_ONESHOT;
- if (hdev->flags & HPET_DEV_PERI_CAP) {
- evt->features |= CLOCK_EVT_FEAT_PERIODIC;
- evt->set_state_periodic = hpet_msi_set_periodic;
- }
-
- evt->set_state_shutdown = hpet_msi_shutdown;
- evt->set_state_oneshot = hpet_msi_set_oneshot;
- evt->tick_resume = hpet_msi_resume;
- evt->set_next_event = hpet_msi_next_event;
- evt->cpumask = cpumask_of(hdev->cpu);
+ hpet_init_clockevent(hc, 110);
+ evt->tick_resume = hpet_clkevt_msi_resume;
clockevents_config_and_register(evt, hpet_freq, HPET_MIN_PROG_DELTA,
0x7FFFFFFF);
}
-#ifdef CONFIG_HPET
-/* Reserve at least one timer for userspace (/dev/hpet) */
-#define RESERVE_TIMERS 1
-#else
-#define RESERVE_TIMERS 0
-#endif
-
-static void hpet_msi_capability_lookup(unsigned int start_timer)
+static struct hpet_channel *hpet_get_unused_clockevent(void)
{
- unsigned int id;
- unsigned int num_timers;
- unsigned int num_timers_used = 0;
- int i, irq;
+ int i;
- if (hpet_msi_disable)
+ for (i = 0; i < hpet_base.nr_channels; i++) {
+ struct hpet_channel *hc = hpet_base.channels + i;
+
+ if (hc->mode != HPET_MODE_CLOCKEVT || hc->in_use)
+ continue;
+ hc->in_use = 1;
+ return hc;
+ }
+ return NULL;
+}
+
+static int hpet_cpuhp_online(unsigned int cpu)
+{
+ struct hpet_channel *hc = hpet_get_unused_clockevent();
+
+ if (hc)
+ init_one_hpet_msi_clockevent(hc, cpu);
+ return 0;
+}
+
+static int hpet_cpuhp_dead(unsigned int cpu)
+{
+ struct hpet_channel *hc = per_cpu(cpu_hpet_channel, cpu);
+
+ if (!hc)
+ return 0;
+ free_irq(hc->irq, hc);
+ hc->in_use = 0;
+ per_cpu(cpu_hpet_channel, cpu) = NULL;
+ return 0;
+}
+
+static void __init hpet_select_clockevents(void)
+{
+ unsigned int i;
+
+ hpet_base.nr_clockevents = 0;
+
+ /* 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;
- if (boot_cpu_has(X86_FEATURE_ARAT))
- return;
- id = hpet_readl(HPET_ID);
-
- num_timers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT);
- num_timers++; /* Value read out starts from 0 */
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;
- hpet_num_timers = num_timers;
-
- for (i = start_timer; i < num_timers - RESERVE_TIMERS; i++) {
- struct hpet_dev *hdev = &hpet_devs[num_timers_used];
- unsigned int cfg = hpet_readl(HPET_Tn_CFG(i));
-
- /* Only consider HPET timer with MSI support */
- if (!(cfg & HPET_TN_FSB_CAP))
+ if (hc->mode != HPET_MODE_UNUSED)
continue;
- hdev->flags = 0;
- if (cfg & HPET_TN_PERIODIC_CAP)
- hdev->flags |= HPET_DEV_PERI_CAP;
- sprintf(hdev->name, "hpet%d", i);
- hdev->num = i;
+ /* Only consider HPET channel with MSI support */
+ if (!(hc->boot_cfg & HPET_TN_FSB_CAP))
+ continue;
- irq = hpet_assign_irq(hpet_domain, hdev, hdev->num);
+ sprintf(hc->name, "hpet%d", i);
+
+ irq = hpet_assign_irq(hpet_domain, hc, hc->num);
if (irq <= 0)
continue;
- hdev->irq = irq;
- hdev->flags |= HPET_DEV_FSB_CAP;
- hdev->flags |= HPET_DEV_VALID;
- num_timers_used++;
- if (num_timers_used == num_possible_cpus())
+ hc->irq = irq;
+ hc->mode = HPET_MODE_CLOCKEVT;
+
+ if (++hpet_base.nr_clockevents == num_possible_cpus())
break;
}
- printk(KERN_INFO "HPET: %d timers in total, %d timers will be used for per-cpu timer\n",
- num_timers, num_timers_used);
+ pr_info("%d channels of %d reserved for per-cpu timers\n",
+ hpet_base.nr_channels, hpet_base.nr_clockevents);
}
-#ifdef CONFIG_HPET
-static void hpet_reserve_msi_timers(struct hpet_data *hd)
-{
- int i;
-
- if (!hpet_devs)
- return;
-
- for (i = 0; i < hpet_num_timers; i++) {
- struct hpet_dev *hdev = &hpet_devs[i];
-
- if (!(hdev->flags & HPET_DEV_VALID))
- continue;
-
- hd->hd_irq[hdev->num] = hdev->irq;
- hpet_reserve_timer(hd, hdev->num);
- }
-}
-#endif
-
-static struct hpet_dev *hpet_get_unused_timer(void)
-{
- int i;
-
- if (!hpet_devs)
- return NULL;
-
- for (i = 0; i < hpet_num_timers; i++) {
- struct hpet_dev *hdev = &hpet_devs[i];
-
- if (!(hdev->flags & HPET_DEV_VALID))
- continue;
- if (test_and_set_bit(HPET_DEV_USED_BIT,
- (unsigned long *)&hdev->flags))
- continue;
- return hdev;
- }
- return NULL;
-}
-
-struct hpet_work_struct {
- struct delayed_work work;
- struct completion complete;
-};
-
-static void hpet_work(struct work_struct *w)
-{
- struct hpet_dev *hdev;
- int cpu = smp_processor_id();
- struct hpet_work_struct *hpet_work;
-
- hpet_work = container_of(w, struct hpet_work_struct, work.work);
-
- hdev = hpet_get_unused_timer();
- if (hdev)
- init_one_hpet_msi_clockevent(hdev, cpu);
-
- complete(&hpet_work->complete);
-}
-
-static int hpet_cpuhp_online(unsigned int cpu)
-{
- struct hpet_work_struct work;
-
- INIT_DELAYED_WORK_ONSTACK(&work.work, hpet_work);
- init_completion(&work.complete);
- /* FIXME: add schedule_work_on() */
- schedule_delayed_work_on(cpu, &work.work, 0);
- wait_for_completion(&work.complete);
- destroy_delayed_work_on_stack(&work.work);
- return 0;
-}
-
-static int hpet_cpuhp_dead(unsigned int cpu)
-{
- struct hpet_dev *hdev = per_cpu(cpu_hpet_dev, cpu);
-
- if (!hdev)
- return 0;
- free_irq(hdev->irq, hdev);
- hdev->flags &= ~HPET_DEV_USED;
- per_cpu(cpu_hpet_dev, cpu) = NULL;
- return 0;
-}
#else
-static void hpet_msi_capability_lookup(unsigned int start_timer)
-{
- return;
-}
-
-#ifdef CONFIG_HPET
-static void hpet_reserve_msi_timers(struct hpet_data *hd)
-{
- return;
-}
-#endif
+static inline void hpet_select_clockevents(void) { }
#define hpet_cpuhp_online NULL
#define hpet_cpuhp_dead NULL
@@ -757,10 +651,10 @@
/*
* Reading the HPET counter is a very slow operation. If a large number of
* CPUs are trying to access the HPET counter simultaneously, it can cause
- * massive delay and slow down system performance dramatically. This may
+ * massive delays and slow down system performance dramatically. This may
* happen when HPET is the default clock source instead of TSC. For a
* really large system with hundreds of CPUs, the slowdown may be so
- * severe that it may actually crash the system because of a NMI watchdog
+ * severe, that it can actually crash the system because of a NMI watchdog
* soft lockup, for example.
*
* If multiple CPUs are trying to access the HPET counter at the same time,
@@ -769,10 +663,9 @@
*
* This special feature is only enabled on x86-64 systems. It is unlikely
* that 32-bit x86 systems will have enough CPUs to require this feature
- * with its associated locking overhead. And we also need 64-bit atomic
- * read.
+ * with its associated locking overhead. We also need 64-bit atomic read.
*
- * The lock and the hpet value are stored together and can be read in a
+ * The lock and the HPET value are stored together and can be read in a
* single atomic 64-bit read. It is explicitly assumed that arch_spinlock_t
* is 32 bits in size.
*/
@@ -861,15 +754,40 @@
.resume = hpet_resume_counter,
};
-static int hpet_clocksource_register(void)
+/*
+ * AMD SB700 based systems with spread spectrum enabled use a SMM based
+ * HPET emulation to provide proper frequency setting.
+ *
+ * On such systems the SMM code is initialized with the first HPET register
+ * access and takes some time to complete. During this time the config
+ * register reads 0xffffffff. We check for max 1000 loops whether the
+ * config register reads a non-0xffffffff value to make sure that the
+ * HPET is up and running before we proceed any further.
+ *
+ * A counting loop is safe, as the HPET access takes thousands of CPU cycles.
+ *
+ * On non-SB700 based machines this check is only done once and has no
+ * side effects.
+ */
+static bool __init hpet_cfg_working(void)
{
- u64 start, now;
- u64 t1;
+ int i;
- /* Start the counter */
+ for (i = 0; i < 1000; i++) {
+ if (hpet_readl(HPET_CFG) != 0xFFFFFFFF)
+ return true;
+ }
+
+ pr_warn("Config register invalid. Disabling HPET\n");
+ return false;
+}
+
+static bool __init hpet_counting(void)
+{
+ u64 start, now, t1;
+
hpet_restart_counter();
- /* Verify whether hpet counter works */
t1 = hpet_readl(HPET_COUNTER);
start = rdtsc();
@@ -880,72 +798,124 @@
* 1 GHz == 200us
*/
do {
- rep_nop();
+ if (t1 != hpet_readl(HPET_COUNTER))
+ return true;
now = rdtsc();
} while ((now - start) < 200000UL);
- if (t1 == hpet_readl(HPET_COUNTER)) {
- printk(KERN_WARNING
- "HPET counter not counting. HPET disabled\n");
- return -ENODEV;
- }
-
- clocksource_register_hz(&clocksource_hpet, (u32)hpet_freq);
- return 0;
+ pr_warn("Counter not counting. HPET disabled\n");
+ return false;
}
-static u32 *hpet_boot_cfg;
+static bool __init mwait_pc10_supported(void)
+{
+ unsigned int eax, ebx, ecx, mwait_substates;
+
+ if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
+ return false;
+
+ if (!cpu_feature_enabled(X86_FEATURE_MWAIT))
+ return false;
+
+ if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
+ return false;
+
+ cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
+
+ return (ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) &&
+ (ecx & CPUID5_ECX_INTERRUPT_BREAK) &&
+ (mwait_substates & (0xF << 28));
+}
+
+/*
+ * Check whether the system supports PC10. If so force disable HPET as that
+ * stops counting in PC10. This check is overbroad as it does not take any
+ * of the following into account:
+ *
+ * - ACPI tables
+ * - Enablement of intel_idle
+ * - Command line arguments which limit intel_idle C-state support
+ *
+ * That's perfectly fine. HPET is a piece of hardware designed by committee
+ * and the only reasons why it is still in use on modern systems is the
+ * fact that it is impossible to reliably query TSC and CPU frequency via
+ * CPUID or firmware.
+ *
+ * If HPET is functional it is useful for calibrating TSC, but this can be
+ * done via PMTIMER as well which seems to be the last remaining timer on
+ * X86/INTEL platforms that has not been completely wreckaged by feature
+ * creep.
+ *
+ * In theory HPET support should be removed altogether, but there are older
+ * systems out there which depend on it because TSC and APIC timer are
+ * dysfunctional in deeper C-states.
+ *
+ * It's only 20 years now that hardware people have been asked to provide
+ * reliable and discoverable facilities which can be used for timekeeping
+ * and per CPU timer interrupts.
+ *
+ * The probability that this problem is going to be solved in the
+ * forseeable future is close to zero, so the kernel has to be cluttered
+ * with heuristics to keep up with the ever growing amount of hardware and
+ * firmware trainwrecks. Hopefully some day hardware people will understand
+ * that the approach of "This can be fixed in software" is not sustainable.
+ * Hope dies last...
+ */
+static bool __init hpet_is_pc10_damaged(void)
+{
+ unsigned long long pcfg;
+
+ /* Check whether PC10 substates are supported */
+ if (!mwait_pc10_supported())
+ return false;
+
+ /* Check whether PC10 is enabled in PKG C-state limit */
+ rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, pcfg);
+ if ((pcfg & 0xF) < 8)
+ return false;
+
+ if (hpet_force_user) {
+ pr_warn("HPET force enabled via command line, but dysfunctional in PC10.\n");
+ return false;
+ }
+
+ pr_info("HPET dysfunctional in PC10. Force disabled.\n");
+ boot_hpet_disable = true;
+ return true;
+}
/**
* hpet_enable - Try to setup the HPET timer. Returns 1 on success.
*/
int __init hpet_enable(void)
{
- u32 hpet_period, cfg, id;
+ u32 hpet_period, cfg, id, irq;
+ unsigned int i, channels;
+ struct hpet_channel *hc;
u64 freq;
- unsigned int i, last;
if (!is_hpet_capable())
+ return 0;
+
+ if (hpet_is_pc10_damaged())
return 0;
hpet_set_mapping();
if (!hpet_virt_address)
return 0;
+ /* Validate that the config register is working */
+ if (!hpet_cfg_working())
+ goto out_nohpet;
+
/*
* Read the period and check for a sane value:
*/
hpet_period = hpet_readl(HPET_PERIOD);
-
- /*
- * AMD SB700 based systems with spread spectrum enabled use a
- * SMM based HPET emulation to provide proper frequency
- * setting. The SMM code is initialized with the first HPET
- * register access and takes some time to complete. During
- * this time the config register reads 0xffffffff. We check
- * for max. 1000 loops whether the config register reads a non
- * 0xffffffff value to make sure that HPET is up and running
- * before we go further. A counting loop is safe, as the HPET
- * access takes thousands of CPU cycles. On non SB700 based
- * machines this check is only done once and has no side
- * effects.
- */
- for (i = 0; hpet_readl(HPET_CFG) == 0xFFFFFFFF; i++) {
- if (i == 1000) {
- printk(KERN_WARNING
- "HPET config register value = 0xFFFFFFFF. "
- "Disabling HPET\n");
- goto out_nohpet;
- }
- }
-
if (hpet_period < HPET_MIN_PERIOD || hpet_period > HPET_MAX_PERIOD)
goto out_nohpet;
- /*
- * The period is a femto seconds value. Convert it to a
- * frequency.
- */
+ /* The period is a femtoseconds value. Convert it to a frequency. */
freq = FSEC_PER_SEC;
do_div(freq, hpet_period);
hpet_freq = freq;
@@ -957,71 +927,97 @@
id = hpet_readl(HPET_ID);
hpet_print_config();
- last = (id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT;
+ /* This is the HPET channel number which is zero based */
+ channels = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
-#ifdef CONFIG_HPET_EMULATE_RTC
/*
* The legacy routing mode needs at least two channels, tick timer
* and the rtc emulation channel.
*/
- if (!last)
+ if (IS_ENABLED(CONFIG_HPET_EMULATE_RTC) && channels < 2)
goto out_nohpet;
-#endif
+ hc = kcalloc(channels, sizeof(*hc), GFP_KERNEL);
+ if (!hc) {
+ pr_warn("Disabling HPET.\n");
+ goto out_nohpet;
+ }
+ hpet_base.channels = hc;
+ hpet_base.nr_channels = channels;
+
+ /* Read, store and sanitize the global configuration */
cfg = hpet_readl(HPET_CFG);
- hpet_boot_cfg = kmalloc_array(last + 2, sizeof(*hpet_boot_cfg),
- GFP_KERNEL);
- if (hpet_boot_cfg)
- *hpet_boot_cfg = cfg;
- else
- pr_warn("HPET initial state will not be saved\n");
+ hpet_base.boot_cfg = cfg;
cfg &= ~(HPET_CFG_ENABLE | HPET_CFG_LEGACY);
hpet_writel(cfg, HPET_CFG);
if (cfg)
- pr_warn("Unrecognized bits %#x set in global cfg\n", cfg);
+ pr_warn("Global config: Unknown bits %#x\n", cfg);
- for (i = 0; i <= last; ++i) {
+ /* Read, store and sanitize the per channel configuration */
+ for (i = 0; i < channels; i++, hc++) {
+ hc->num = i;
+
cfg = hpet_readl(HPET_Tn_CFG(i));
- if (hpet_boot_cfg)
- hpet_boot_cfg[i + 1] = cfg;
+ hc->boot_cfg = cfg;
+ irq = (cfg & Tn_INT_ROUTE_CNF_MASK) >> Tn_INT_ROUTE_CNF_SHIFT;
+ hc->irq = irq;
+
cfg &= ~(HPET_TN_ENABLE | HPET_TN_LEVEL | HPET_TN_FSB);
hpet_writel(cfg, HPET_Tn_CFG(i));
+
cfg &= ~(HPET_TN_PERIODIC | HPET_TN_PERIODIC_CAP
| HPET_TN_64BIT_CAP | HPET_TN_32BIT | HPET_TN_ROUTE
| HPET_TN_FSB | HPET_TN_FSB_CAP);
if (cfg)
- pr_warn("Unrecognized bits %#x set in cfg#%u\n",
- cfg, i);
+ pr_warn("Channel #%u config: Unknown bits %#x\n", i, cfg);
}
hpet_print_config();
- if (hpet_clocksource_register())
+ /*
+ * Validate that the counter is counting. This needs to be done
+ * after sanitizing the config registers to properly deal with
+ * force enabled HPETs.
+ */
+ if (!hpet_counting())
goto out_nohpet;
+ clocksource_register_hz(&clocksource_hpet, (u32)hpet_freq);
+
if (id & HPET_ID_LEGSUP) {
- hpet_legacy_clockevent_register();
+ hpet_legacy_clockevent_register(&hpet_base.channels[0]);
+ hpet_base.channels[0].mode = HPET_MODE_LEGACY;
+ if (IS_ENABLED(CONFIG_HPET_EMULATE_RTC))
+ hpet_base.channels[1].mode = HPET_MODE_LEGACY;
return 1;
}
return 0;
out_nohpet:
+ kfree(hpet_base.channels);
+ hpet_base.channels = NULL;
+ hpet_base.nr_channels = 0;
hpet_clear_mapping();
hpet_address = 0;
return 0;
}
/*
- * Needs to be late, as the reserve_timer code calls kalloc !
+ * The late initialization runs after the PCI quirks have been invoked
+ * which might have detected a system on which the HPET can be enforced.
*
- * Not a problem on i386 as hpet_enable is called from late_time_init,
- * but on x86_64 it is necessary !
+ * 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)
{
int ret;
-
- if (boot_hpet_disable)
- return -ENODEV;
if (!hpet_address) {
if (!force_hpet_address)
@@ -1034,21 +1030,14 @@
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_select_device_channel();
+ hpet_select_clockevents();
+ hpet_reserve_platform_timers();
hpet_print_config();
- if (hpet_msi_disable)
+ if (!hpet_base.nr_clockevents)
return 0;
- if (boot_cpu_has(X86_FEATURE_ARAT))
- return 0;
-
- /* This notifier should be called after workqueue is ready */
ret = cpuhp_setup_state(CPUHP_AP_X86_HPET_ONLINE, "x86/hpet:online",
hpet_cpuhp_online, NULL);
if (ret)
@@ -1067,47 +1056,47 @@
void hpet_disable(void)
{
- if (is_hpet_capable() && hpet_virt_address) {
- unsigned int cfg = hpet_readl(HPET_CFG), id, last;
+ unsigned int i;
+ u32 cfg;
- if (hpet_boot_cfg)
- cfg = *hpet_boot_cfg;
- else if (hpet_legacy_int_enabled) {
- cfg &= ~HPET_CFG_LEGACY;
- hpet_legacy_int_enabled = false;
- }
- cfg &= ~HPET_CFG_ENABLE;
- hpet_writel(cfg, HPET_CFG);
+ if (!is_hpet_capable() || !hpet_virt_address)
+ return;
- if (!hpet_boot_cfg)
- return;
+ /* Restore boot configuration with the enable bit cleared */
+ cfg = hpet_base.boot_cfg;
+ cfg &= ~HPET_CFG_ENABLE;
+ hpet_writel(cfg, HPET_CFG);
- id = hpet_readl(HPET_ID);
- last = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT);
+ /* Restore the channel boot configuration */
+ for (i = 0; i < hpet_base.nr_channels; i++)
+ hpet_writel(hpet_base.channels[i].boot_cfg, HPET_Tn_CFG(i));
- for (id = 0; id <= last; ++id)
- hpet_writel(hpet_boot_cfg[id + 1], HPET_Tn_CFG(id));
-
- if (*hpet_boot_cfg & HPET_CFG_ENABLE)
- hpet_writel(*hpet_boot_cfg, HPET_CFG);
- }
+ /* If the HPET was enabled at boot time, reenable it */
+ if (hpet_base.boot_cfg & HPET_CFG_ENABLE)
+ hpet_writel(hpet_base.boot_cfg, HPET_CFG);
}
#ifdef CONFIG_HPET_EMULATE_RTC
-/* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET
+/*
+ * HPET in LegacyReplacement mode eats up the RTC interrupt line. When HPET
* is enabled, we support RTC interrupt functionality in software.
+ *
* RTC has 3 kinds of interrupts:
- * 1) Update Interrupt - generate an interrupt, every sec, when RTC clock
- * is updated
- * 2) Alarm Interrupt - generate an interrupt at a specific time of day
- * 3) Periodic Interrupt - generate periodic interrupt, with frequencies
- * 2Hz-8192Hz (2Hz-64Hz for non-root user) (all freqs in powers of 2)
- * (1) and (2) above are implemented using polling at a frequency of
- * 64 Hz. The exact frequency is a tradeoff between accuracy and interrupt
- * overhead. (DEFAULT_RTC_INT_FREQ)
- * For (3), we use interrupts at 64Hz or user specified periodic
- * frequency, whichever is higher.
+ *
+ * 1) Update Interrupt - generate an interrupt, every second, when the
+ * RTC clock is updated
+ * 2) Alarm Interrupt - generate an interrupt at a specific time of day
+ * 3) Periodic Interrupt - generate periodic interrupt, with frequencies
+ * 2Hz-8192Hz (2Hz-64Hz for non-root user) (all frequencies in powers of 2)
+ *
+ * (1) and (2) above are implemented using polling at a frequency of 64 Hz:
+ * DEFAULT_RTC_INT_FREQ.
+ *
+ * The exact frequency is a tradeoff between accuracy and interrupt overhead.
+ *
+ * For (3), we use interrupts at 64 Hz, or the user specified periodic frequency,
+ * if it's higher.
*/
#include <linux/mc146818rtc.h>
#include <linux/rtc.h>
@@ -1128,7 +1117,7 @@
static rtc_irq_handler irq_handler;
/*
- * Check that the hpet counter c1 is ahead of the c2
+ * Check that the HPET counter c1 is ahead of c2
*/
static inline int hpet_cnt_ahead(u32 c1, u32 c2)
{
@@ -1166,8 +1155,8 @@
EXPORT_SYMBOL_GPL(hpet_unregister_irq_handler);
/*
- * Timer 1 for RTC emulation. We use one shot mode, as periodic mode
- * is not supported by all HPET implementations for timer 1.
+ * Channel 1 for RTC emulation. We use one shot mode, as periodic mode
+ * is not supported by all HPET implementations for channel 1.
*
* hpet_rtc_timer_init() is called when the rtc is initialized.
*/
@@ -1180,10 +1169,11 @@
return 0;
if (!hpet_default_delta) {
+ struct clock_event_device *evt = &hpet_base.channels[0].evt;
uint64_t clc;
- clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
- clc >>= hpet_clockevent.shift + DEFAULT_RTC_SHIFT;
+ clc = (uint64_t) evt->mult * NSEC_PER_SEC;
+ clc >>= evt->shift + DEFAULT_RTC_SHIFT;
hpet_default_delta = clc;
}
@@ -1212,6 +1202,7 @@
static void hpet_disable_rtc_channel(void)
{
u32 cfg = hpet_readl(HPET_T1_CFG);
+
cfg &= ~HPET_TN_ENABLE;
hpet_writel(cfg, HPET_T1_CFG);
}
@@ -1253,8 +1244,7 @@
}
EXPORT_SYMBOL_GPL(hpet_set_rtc_irq_bit);
-int hpet_set_alarm_time(unsigned char hrs, unsigned char min,
- unsigned char sec)
+int hpet_set_alarm_time(unsigned char hrs, unsigned char min, unsigned char sec)
{
if (!is_hpet_enabled())
return 0;
@@ -1274,15 +1264,18 @@
if (!is_hpet_enabled())
return 0;
- if (freq <= DEFAULT_RTC_INT_FREQ)
+ if (freq <= DEFAULT_RTC_INT_FREQ) {
hpet_pie_limit = DEFAULT_RTC_INT_FREQ / freq;
- else {
- clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
+ } else {
+ struct clock_event_device *evt = &hpet_base.channels[0].evt;
+
+ clc = (uint64_t) evt->mult * NSEC_PER_SEC;
do_div(clc, freq);
- clc >>= hpet_clockevent.shift;
+ clc >>= evt->shift;
hpet_pie_delta = clc;
hpet_pie_limit = 0;
}
+
return 1;
}
EXPORT_SYMBOL_GPL(hpet_set_periodic_freq);
@@ -1320,8 +1313,7 @@
if (hpet_rtc_flags & RTC_PIE)
hpet_pie_count += lost_ints;
if (printk_ratelimit())
- printk(KERN_WARNING "hpet1: lost %d rtc interrupts\n",
- lost_ints);
+ pr_warn("Lost %d RTC interrupts\n", lost_ints);
}
}
@@ -1333,8 +1325,12 @@
hpet_rtc_timer_reinit();
memset(&curr_time, 0, sizeof(struct rtc_time));
- if (hpet_rtc_flags & (RTC_UIE | RTC_AIE))
- mc146818_get_time(&curr_time);
+ if (hpet_rtc_flags & (RTC_UIE | RTC_AIE)) {
+ if (unlikely(mc146818_get_time(&curr_time) < 0)) {
+ pr_err_ratelimited("unable to read current time from RTC\n");
+ return IRQ_HANDLED;
+ }
+ }
if (hpet_rtc_flags & RTC_UIE &&
curr_time.tm_sec != hpet_prev_update_sec) {
@@ -1343,8 +1339,7 @@
hpet_prev_update_sec = curr_time.tm_sec;
}
- if (hpet_rtc_flags & RTC_PIE &&
- ++hpet_pie_count >= hpet_pie_limit) {
+ if (hpet_rtc_flags & RTC_PIE && ++hpet_pie_count >= hpet_pie_limit) {
rtc_int_flag |= RTC_PF;
hpet_pie_count = 0;
}
@@ -1353,7 +1348,7 @@
(curr_time.tm_sec == hpet_alarm_time.tm_sec) &&
(curr_time.tm_min == hpet_alarm_time.tm_min) &&
(curr_time.tm_hour == hpet_alarm_time.tm_hour))
- rtc_int_flag |= RTC_AF;
+ rtc_int_flag |= RTC_AF;
if (rtc_int_flag) {
rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8));
--
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