From e3f37a54f690d3e64995ea7ecea08c5ab3070faf Mon Sep 17 00:00:00 2001 From: Balaji Rao Date: Wed, 30 Jan 2008 13:30:03 +0100 Subject: [PATCH] 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: Balaji Rao Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/hpet.c | 13 +++++------- drivers/char/hpet.c | 45 +++++++++++++++++++++++++++++++++++------- include/linux/hpet.h | 2 +- 3 files changed, 44 insertions(+), 16 deletions(-) diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c index 9ec2ab79304..786aa227afd 100644 --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -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) { } diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c index 4c16778e3f8..593b32cfbc3 100644 --- a/drivers/char/hpet.c +++ b/drivers/char/hpet.c @@ -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", diff --git a/include/linux/hpet.h b/include/linux/hpet.h index 707f7cb9e79..e3c0b2aa944 100644 --- a/include/linux/hpet.h +++ b/include/linux/hpet.h @@ -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) -- 2.41.1