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 <balajirrao@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index 4c16778..593b32c 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -806,14 +806,14 @@
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;
/*
@@ -840,12 +840,42 @@
hpetp->hp_hpet_phys = hdp->hd_phys_address;
hpetp->hp_ntimer = hdp->hd_nirqs;
-
- for (i = 0; i < hdp->hd_nirqs; i++)
- hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
-
hpet = hpetp->hp_hpet;
+ /* 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];
+
+ /* 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);
ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
@@ -875,7 +905,8 @@
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",