[tip:x86/timers] x86/hpet: Use cached info instead of extra flags

From: tip-bot for Thomas Gleixner
Date: Thu Jun 27 2019 - 19:50:42 EST


Commit-ID: 45e0a415634600e608188480bc355b20344f9e3f
Gitweb: https://git.kernel.org/tip/45e0a415634600e608188480bc355b20344f9e3f
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Sun, 23 Jun 2019 15:24:04 +0200
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 28 Jun 2019 00:57:25 +0200

x86/hpet: Use cached info instead of extra flags

Now that HPET clockevent support is integrated into the channel data, reuse
the cached boot configuration instead of copying the same information into
a flags field.

This also allows to consolidate the reservation code into one place, which
can now solely depend on the mode information.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx>
Cc: Ashok Raj <ashok.raj@xxxxxxxxx>
Cc: Andi Kleen <andi.kleen@xxxxxxxxx>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Ravi Shankar <ravi.v.shankar@xxxxxxxxx>
Link: https://lkml.kernel.org/r/20190623132436.277510163@xxxxxxxxxxxxx

---
arch/x86/kernel/hpet.c | 76 +++++++++++++++-----------------------------------
1 file changed, 23 insertions(+), 53 deletions(-)

diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 7f76f07138a6..985a2246d20c 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -25,8 +25,8 @@ struct hpet_channel {
unsigned int num;
unsigned int cpu;
unsigned int irq;
+ unsigned int in_use;
enum hpet_mode mode;
- unsigned int flags;
unsigned int boot_cfg;
char name[10];
};
@@ -40,12 +40,6 @@ struct hpet_base {

#define HPET_MASK CLOCKSOURCE_MASK(32)

-#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))

@@ -62,6 +56,7 @@ static struct irq_domain *hpet_domain;
#endif

static void __iomem *hpet_virt_address;
+
static struct hpet_base hpet_base;

static bool hpet_legacy_int_enabled;
@@ -190,8 +185,6 @@ do { \
*/
#ifdef CONFIG_HPET

-static void hpet_reserve_msi_timers(struct hpet_data *hd);
-
static void __init hpet_reserve_platform_timers(void)
{
struct hpet_data hd;
@@ -201,11 +194,6 @@ static void __init hpet_reserve_platform_timers(void)
hd.hd_phys_address = hpet_address;
hd.hd_address = hpet_virt_address;
hd.hd_nirqs = hpet_base.nr_channels;
- hpet_reserve_timer(&hd, 0);
-
-#ifdef CONFIG_HPET_EMULATE_RTC
- hpet_reserve_timer(&hd, 1);
-#endif

/*
* NOTE that hd_irq[] reflects IOAPIC input pins (LEGACY_8254
@@ -215,13 +203,25 @@ static void __init hpet_reserve_platform_timers(void)
hd.hd_irq[0] = HPET_LEGACY_8254;
hd.hd_irq[1] = HPET_LEGACY_RTC;

- for (i = 2; i < hpet_base.nr_channels; i++)
- hd.hd_irq[i] = hpet_base.channels[i].irq;
+ for (i = 0; i < hpet_base.nr_channels; i++) {
+ struct hpet_channel *hc = hpet_base.channels + i;

- hpet_reserve_msi_timers(&hd);
+ if (i >= 2)
+ hd.hd_irq[i] = hc->irq;

- hpet_alloc(&hd);
+ 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_alloc(&hd);
}

static void __init hpet_select_device_channel(void)
@@ -543,13 +543,11 @@ static int hpet_setup_irq(struct hpet_channel *hc)
return 0;
}

+/* 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 = &hc->evt;

- if (!(hc->flags & HPET_DEV_VALID))
- return;
-
hc->cpu = cpu;
per_cpu(cpu_hpet_channel, cpu) = hc;
evt->name = hc->name;
@@ -558,7 +556,7 @@ static void init_one_hpet_msi_clockevent(struct hpet_channel *hc, int cpu)

evt->rating = 110;
evt->features = CLOCK_EVT_FEAT_ONESHOT;
- if (hc->flags & HPET_DEV_PERI_CAP) {
+ if (hc->boot_cfg & HPET_TN_PERIODIC) {
evt->features |= CLOCK_EVT_FEAT_PERIODIC;
evt->set_state_periodic = hpet_msi_set_periodic;
}
@@ -580,11 +578,9 @@ static struct hpet_channel *hpet_get_unused_clockevent(void)
for (i = 0; i < hpet_base.nr_channels; i++) {
struct hpet_channel *hc = hpet_base.channels + i;

- if (!(hc->flags & HPET_DEV_VALID))
- continue;
- if (test_and_set_bit(HPET_DEV_USED_BIT,
- (unsigned long *)&hc->flags))
+ if (hc->mode != HPET_MODE_CLOCKEVT || hc->in_use)
continue;
+ hc->in_use = 1;
return hc;
}
return NULL;
@@ -606,7 +602,7 @@ static int hpet_cpuhp_dead(unsigned int cpu)
if (!hc)
return 0;
free_irq(hc->irq, hc);
- hc->flags &= ~HPET_DEV_USED;
+ hc->in_use = 0;
per_cpu(cpu_hpet_channel, cpu) = NULL;
return 0;
}
@@ -638,9 +634,6 @@ static void __init hpet_select_clockevents(void)
if (!(hc->boot_cfg & HPET_TN_FSB_CAP))
continue;

- hc->flags = 0;
- if (hc->boot_cfg & HPET_TN_PERIODIC_CAP)
- hc->flags |= HPET_DEV_PERI_CAP;
sprintf(hc->name, "hpet%d", i);

irq = hpet_assign_irq(hpet_domain, hc, hc->num);
@@ -648,8 +641,6 @@ static void __init hpet_select_clockevents(void)
continue;

hc->irq = irq;
- hc->flags |= HPET_DEV_FSB_CAP;
- hc->flags |= HPET_DEV_VALID;
hc->mode = HPET_MODE_CLOCKEVT;

if (++hpet_base.nr_clockevents == num_possible_cpus())
@@ -660,31 +651,10 @@ static void __init hpet_select_clockevents(void)
hpet_base.nr_channels, hpet_base.nr_clockevents);
}

-#ifdef CONFIG_HPET
-static void __init hpet_reserve_msi_timers(struct hpet_data *hd)
-{
- int i;
-
- for (i = 0; i < hpet_base.nr_channels; i++) {
- struct hpet_channel *hc = hpet_base.channels + i;
-
- if (!(hc->flags & HPET_DEV_VALID))
- continue;
-
- hd->hd_irq[hc->num] = hc->irq;
- hpet_reserve_timer(hd, hc->num);
- }
-}
-#endif
-
#else

static inline void hpet_select_clockevents(void) { }

-#ifdef CONFIG_HPET
-static inline void hpet_reserve_msi_timers(struct hpet_data *hd) { }
-#endif
-
#define hpet_cpuhp_online NULL
#define hpet_cpuhp_dead NULL