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authorArthur Jones <arthur.jones@qlogic.com>2007-05-10 12:10:49 -0700
committerRoland Dreier <rolandd@cisco.com>2007-05-14 13:22:42 -0700
commit8f140b407f3be04e7202be9aa0cfef3006d14c9f (patch)
tree34f308cacd261f03cc3e490a187df369f0bac7f3 /drivers/infiniband/hw/ipath/ipath_verbs.c
parent26c6bc7b812b4157ba929035e467c0f4dd165916 (diff)
IB/ipath: Shadow the gpio_mask register
Once upon a time, GPIO interrupts were rare. But then a chip bug in the waldo series forced the use of a GPIO interrupt to signal packet reception. This greatly increased the frequency of GPIO interrupts which have the gpio_mask bits set on the waldo chips. Other bits in the gpio_status register are used for I2C clock and data lines, these bits are usually on. An "unlikely" annotation leftover from the old days was improperly applied to these bits, and an unnecessary chip mmio read was being accessed in the interrupt fast path on waldo. Remove the stagnant unlikely annotation in the interrupt handler and keep a shadow copy of the gpio_mask register to avoid the slow mmio read when testing for interruptable GPIO bits. Signed-off-by: Arthur Jones <arthur.jones@qlogic.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
Diffstat (limited to 'drivers/infiniband/hw/ipath/ipath_verbs.c')
-rw-r--r--drivers/infiniband/hw/ipath/ipath_verbs.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/infiniband/hw/ipath/ipath_verbs.c b/drivers/infiniband/hw/ipath/ipath_verbs.c
index 12933e77c7e9..bb70845279b8 100644
--- a/drivers/infiniband/hw/ipath/ipath_verbs.c
+++ b/drivers/infiniband/hw/ipath/ipath_verbs.c
@@ -1387,13 +1387,12 @@ static int enable_timer(struct ipath_devdata *dd)
* processing.
*/
if (dd->ipath_flags & IPATH_GPIO_INTR) {
- u64 val;
ipath_write_kreg(dd, dd->ipath_kregs->kr_debugportselect,
0x2074076542310ULL);
/* Enable GPIO bit 2 interrupt */
- val = ipath_read_kreg64(dd, dd->ipath_kregs->kr_gpio_mask);
- val |= (u64) (1 << IPATH_GPIO_PORT0_BIT);
- ipath_write_kreg( dd, dd->ipath_kregs->kr_gpio_mask, val);
+ dd->ipath_gpio_mask |= (u64) (1 << IPATH_GPIO_PORT0_BIT);
+ ipath_write_kreg(dd, dd->ipath_kregs->kr_gpio_mask,
+ dd->ipath_gpio_mask);
}
init_timer(&dd->verbs_timer);
@@ -1412,8 +1411,9 @@ static int disable_timer(struct ipath_devdata *dd)
u64 val;
/* Disable GPIO bit 2 interrupt */
val = ipath_read_kreg64(dd, dd->ipath_kregs->kr_gpio_mask);
- val &= ~((u64) (1 << IPATH_GPIO_PORT0_BIT));
- ipath_write_kreg( dd, dd->ipath_kregs->kr_gpio_mask, val);
+ dd->ipath_gpio_mask &= ~((u64) (1 << IPATH_GPIO_PORT0_BIT));
+ ipath_write_kreg(dd, dd->ipath_kregs->kr_gpio_mask,
+ dd->ipath_gpio_mask);
/*
* We might want to undo changes to debugportselect,
* but how?