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Commit e3f37a54 authored by Balaji Rao's avatar Balaji Rao Committed by Ingo Molnar
Browse files

x86: assign IRQs to HPET timers 



The userspace API for the HPET (see Documentation/hpet.txt) did not work. The
HPET_IE_ON ioctl was failing as there was no IRQ assigned to the timer
device. This patch fixes it by allocating IRQs to timer blocks in the HPET.

arch/x86/kernel/hpet.c |   13 +++++--------
drivers/char/hpet.c    |   45 ++++++++++++++++++++++++++++++++++++++-------
include/linux/hpet.h   |    2 +-
3 files changed, 44 insertions(+), 16 deletions(-)

Signed-off-by: default avatarBalaji Rao <balajirrao@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 45fe4fe1

arch/x86/kernel/hpet.c

+5 −8
Original line number Diff line number Diff line
@@ -117,8 +117,7 @@ int is_hpet_enabled(void) 
static void hpet_reserve_platform_timers(unsigned long id)

{

	struct hpet __iomem *hpet = hpet_virt_address;

	struct hpet_timer __iomem *timer = &hpet->hpet_timers[2];

	unsigned int nrtimers, i;

	unsigned int nrtimers;

	struct hpet_data hd;



	nrtimers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
@@ -133,16 +132,14 @@ static void hpet_reserve_platform_timers(unsigned long id) 
#ifdef CONFIG_HPET_EMULATE_RTC

	hpet_reserve_timer(&hd, 1);

#endif



	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] = (timer->hpet_config & Tn_INT_ROUTE_CNF_MASK) >>

			Tn_INT_ROUTE_CNF_SHIFT;



	/*

	 * IRQs for the other timers are assigned dynamically

	 * in hpet_alloc

	 */

	hpet_alloc(&hd);



}

#else

static void hpet_reserve_platform_timers(unsigned long id) { }

drivers/char/hpet.c

+38 −7
Original line number Diff line number Diff line
@@ -806,14 +806,14 @@ static unsigned long hpet_calibrate(struct hpets *hpetp) 


int hpet_alloc(struct hpet_data *hdp)

{

	u64 cap, mcfg;

	u64 cap, mcfg, hpet_config;

	struct hpet_dev *devp;

	u32 i, ntimer;

	u32 i, ntimer, irq;

	struct hpets *hpetp;

	size_t siz;

	struct hpet __iomem *hpet;

	static struct hpets *last = NULL;

	unsigned long period;

	unsigned long period, irq_bitmap;

	unsigned long long temp;



	/*
@@ -840,11 +840,41 @@ int hpet_alloc(struct hpet_data *hdp) 
	hpetp->hp_hpet_phys = hdp->hd_phys_address;



	hpetp->hp_ntimer = hdp->hd_nirqs;

	hpet = hpetp->hp_hpet;



	for (i = 0; i < hdp->hd_nirqs; i++)

		hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];

	/* Assign IRQs statically for legacy devices */

	hpetp->hp_dev[0].hd_hdwirq = hdp->hd_irq[0];

	hpetp->hp_dev[1].hd_hdwirq = hdp->hd_irq[1];



	hpet = hpetp->hp_hpet;

	/* Assign IRQs dynamically for the others */

	for (i = 2, devp = &hpetp->hp_dev[2]; i < hdp->hd_nirqs; i++, devp++) {

		struct hpet_timer __iomem *timer;



		timer = &hpet->hpet_timers[devp - hpetp->hp_dev];



		hpet_config = readq(&timer->hpet_config);

		irq_bitmap = (hpet_config & Tn_INT_ROUTE_CAP_MASK)

			>> Tn_INT_ROUTE_CAP_SHIFT;

		if (!irq_bitmap)

			irq = 0;        /* No valid IRQ Assignable */

		else {

			irq = find_first_bit(&irq_bitmap, 32);

			do {

				hpet_config |= irq << Tn_INT_ROUTE_CNF_SHIFT;

				writeq(hpet_config, &timer->hpet_config);



				/*

				 * Verify whether we have written a valid

				 * IRQ number by reading it back again

				 */

				hpet_config = readq(&timer->hpet_config);

				if (irq == (hpet_config & Tn_INT_ROUTE_CNF_MASK)

						>> Tn_INT_ROUTE_CNF_SHIFT)

					break;  /* Success */

			} while ((irq = (find_next_bit(&irq_bitmap, 32, irq))));

		}

		hpetp->hp_dev[i].hd_hdwirq = irq;

	}



	cap = readq(&hpet->hpet_cap);
@@ -875,7 +905,8 @@ int hpet_alloc(struct hpet_data *hdp) 
		hpetp->hp_which, hdp->hd_phys_address,

		hpetp->hp_ntimer > 1 ? "s" : "");

	for (i = 0; i < hpetp->hp_ntimer; i++)

		printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);

		printk("%s %d", i > 0 ? "," : "",

				hpetp->hp_dev[i].hd_hdwirq);

	printk("\n");



	printk(KERN_INFO "hpet%u: %u %d-bit timers, %Lu Hz\n",

include/linux/hpet.h

+1 −1
Original line number Diff line number Diff line
@@ -64,7 +64,7 @@ struct hpet { 
 */



#define	Tn_INT_ROUTE_CAP_MASK		(0xffffffff00000000ULL)

#define	Tn_INI_ROUTE_CAP_SHIFT		(32UL)

#define	Tn_INT_ROUTE_CAP_SHIFT		(32UL)

#define	Tn_FSB_INT_DELCAP_MASK		(0x8000UL)

#define	Tn_FSB_INT_DELCAP_SHIFT		(15)

#define	Tn_FSB_EN_CNF_MASK		(0x4000UL)