[ofa-general] [PATCH 2/6] IB/ipath - fix sendctrl locking
Arthur Jones
arthur.jones at qlogic.com
Fri Dec 7 08:00:43 PST 2007
From: John Gregor <john.gregor at qlogic.com>
An internal code review pointed out that the locking around uses of
ipath_sendctrl and kr_sendctrl were, in several places, incorrect
and/or inconsistent.
Signed-off-by: John Gregor <john.gregor at qlogic.com>
---
drivers/infiniband/hw/ipath/ipath_driver.c | 40 ++++++++++++++++---------
drivers/infiniband/hw/ipath/ipath_file_ops.c | 10 ++++--
drivers/infiniband/hw/ipath/ipath_init_chip.c | 24 ++++++++++-----
drivers/infiniband/hw/ipath/ipath_intr.c | 19 ++++++++++--
drivers/infiniband/hw/ipath/ipath_kernel.h | 1 +
drivers/infiniband/hw/ipath/ipath_ruc.c | 7 ++++
6 files changed, 72 insertions(+), 29 deletions(-)
diff --git a/drivers/infiniband/hw/ipath/ipath_driver.c b/drivers/infiniband/hw/ipath/ipath_driver.c
index 1f152de..5b84be1 100644
--- a/drivers/infiniband/hw/ipath/ipath_driver.c
+++ b/drivers/infiniband/hw/ipath/ipath_driver.c
@@ -800,31 +800,37 @@ void ipath_disarm_piobufs(struct ipath_devdata *dd, unsigned first,
unsigned cnt)
{
unsigned i, last = first + cnt;
- u64 sendctrl, sendorig;
+ unsigned long flags;
ipath_cdbg(PKT, "disarm %u PIObufs first=%u\n", cnt, first);
- sendorig = dd->ipath_sendctrl;
for (i = first; i < last; i++) {
- sendctrl = sendorig | INFINIPATH_S_DISARM |
- (i << INFINIPATH_S_DISARMPIOBUF_SHIFT);
+ spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
+ /*
+ * The disarm-related bits are write-only, so it
+ * is ok to OR them in with our copy of sendctrl
+ * while we hold the lock.
+ */
ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
- sendctrl);
+ dd->ipath_sendctrl | INFINIPATH_S_DISARM |
+ (i << INFINIPATH_S_DISARMPIOBUF_SHIFT));
+ /* can't disarm bufs back-to-back per iba7220 spec */
+ ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+ spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
}
/*
- * Write it again with current value, in case ipath_sendctrl changed
- * while we were looping; no critical bits that would require
- * locking.
- *
- * disable PIOAVAILUPD, then re-enable, reading scratch in
+ * Disable PIOAVAILUPD, then re-enable, reading scratch in
* between. This seems to avoid a chip timing race that causes
- * pioavail updates to memory to stop.
+ * pioavail updates to memory to stop. We xor as we don't
+ * know the state of the bit when we're called.
*/
+ spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
- sendorig & ~INFINIPATH_S_PIOBUFAVAILUPD);
- sendorig = ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+ dd->ipath_sendctrl ^ INFINIPATH_S_PIOBUFAVAILUPD);
+ ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
dd->ipath_sendctrl);
+ spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
}
/**
@@ -2053,6 +2059,8 @@ void ipath_set_led_override(struct ipath_devdata *dd, unsigned int val)
*/
void ipath_shutdown_device(struct ipath_devdata *dd)
{
+ unsigned long flags;
+
ipath_dbg("Shutting down the device\n");
dd->ipath_flags |= IPATH_LINKUNK;
@@ -2073,9 +2081,13 @@ void ipath_shutdown_device(struct ipath_devdata *dd)
* gracefully stop all sends allowing any in progress to trickle out
* first.
*/
- ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, 0ULL);
+ spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
+ dd->ipath_sendctrl = 0;
+ ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, dd->ipath_sendctrl);
/* flush it */
ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+ spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
+
/*
* enough for anything that's going to trickle out to have actually
* done so.
diff --git a/drivers/infiniband/hw/ipath/ipath_file_ops.c b/drivers/infiniband/hw/ipath/ipath_file_ops.c
index 5de3243..92dae6f 100644
--- a/drivers/infiniband/hw/ipath/ipath_file_ops.c
+++ b/drivers/infiniband/hw/ipath/ipath_file_ops.c
@@ -2149,11 +2149,15 @@ static int ipath_get_slave_info(struct ipath_portdata *pd,
static int ipath_force_pio_avail_update(struct ipath_devdata *dd)
{
- u64 reg = dd->ipath_sendctrl;
+ unsigned long flags;
- clear_bit(IPATH_S_PIOBUFAVAILUPD, ®);
- ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, reg);
+ spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
+ ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
+ dd->ipath_sendctrl & ~INFINIPATH_S_PIOBUFAVAILUPD);
+ ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, dd->ipath_sendctrl);
+ ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+ spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
return 0;
}
diff --git a/drivers/infiniband/hw/ipath/ipath_init_chip.c b/drivers/infiniband/hw/ipath/ipath_init_chip.c
index 9e9d6fa..1c65ab9 100644
--- a/drivers/infiniband/hw/ipath/ipath_init_chip.c
+++ b/drivers/infiniband/hw/ipath/ipath_init_chip.c
@@ -345,7 +345,7 @@ static int init_chip_first(struct ipath_devdata *dd,
dd->ipath_piobcnt2k, dd->ipath_pio2kbase);
spin_lock_init(&dd->ipath_tid_lock);
-
+ spin_lock_init(&dd->ipath_sendctrl_lock);
spin_lock_init(&dd->ipath_gpio_lock);
spin_lock_init(&dd->ipath_eep_st_lock);
mutex_init(&dd->ipath_eep_lock);
@@ -372,9 +372,9 @@ static int init_chip_reset(struct ipath_devdata *dd,
*pdp = dd->ipath_pd[0];
/* ensure chip does no sends or receives while we re-initialize */
dd->ipath_control = dd->ipath_sendctrl = dd->ipath_rcvctrl = 0U;
- ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl, 0);
- ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, 0);
- ipath_write_kreg(dd, dd->ipath_kregs->kr_control, 0);
+ ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl, dd->ipath_rcvctrl);
+ ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, dd->ipath_sendctrl);
+ ipath_write_kreg(dd, dd->ipath_kregs->kr_control, dd->ipath_control);
rtmp = ipath_read_kreg32(dd, dd->ipath_kregs->kr_portcnt);
if (dd->ipath_portcnt != rtmp)
@@ -487,6 +487,7 @@ static void enable_chip(struct ipath_devdata *dd,
struct ipath_portdata *pd, int reinit)
{
u32 val;
+ unsigned long flags;
int i;
if (!reinit)
@@ -495,11 +496,13 @@ static void enable_chip(struct ipath_devdata *dd,
ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl,
dd->ipath_rcvctrl);
+ spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
/* Enable PIO send, and update of PIOavail regs to memory. */
dd->ipath_sendctrl = INFINIPATH_S_PIOENABLE |
INFINIPATH_S_PIOBUFAVAILUPD;
- ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
- dd->ipath_sendctrl);
+ ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, dd->ipath_sendctrl);
+ ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+ spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
/*
* enable port 0 receive, and receive interrupt. other ports
@@ -696,6 +699,7 @@ int ipath_init_chip(struct ipath_devdata *dd, int reinit)
u64 val;
struct ipath_portdata *pd = NULL; /* keep gcc4 happy */
gfp_t gfp_flags = GFP_USER | __GFP_COMP;
+ unsigned long flags;
ret = init_housekeeping(dd, &pd, reinit);
if (ret)
@@ -827,8 +831,12 @@ int ipath_init_chip(struct ipath_devdata *dd, int reinit)
ipath_write_kreg(dd, dd->ipath_kregs->kr_hwerrclear,
~0ULL&~INFINIPATH_HWE_MEMBISTFAILED);
ipath_write_kreg(dd, dd->ipath_kregs->kr_control, 0ULL);
- ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
- INFINIPATH_S_PIOENABLE);
+
+ spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
+ dd->ipath_sendctrl = INFINIPATH_S_PIOENABLE;
+ ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, dd->ipath_sendctrl);
+ ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+ spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
/*
* before error clears, since we expect serdes pll errors during
diff --git a/drivers/infiniband/hw/ipath/ipath_intr.c b/drivers/infiniband/hw/ipath/ipath_intr.c
index ad41ccc..eac2e9c 100644
--- a/drivers/infiniband/hw/ipath/ipath_intr.c
+++ b/drivers/infiniband/hw/ipath/ipath_intr.c
@@ -795,6 +795,7 @@ void ipath_clear_freeze(struct ipath_devdata *dd)
{
int i, im;
__le64 val;
+ unsigned long flags;
/* disable error interrupts, to avoid confusion */
ipath_write_kreg(dd, dd->ipath_kregs->kr_errormask, 0ULL);
@@ -813,11 +814,14 @@ void ipath_clear_freeze(struct ipath_devdata *dd)
dd->ipath_control);
/* ensure pio avail updates continue */
+ spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
dd->ipath_sendctrl & ~INFINIPATH_S_PIOBUFAVAILUPD);
ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
- dd->ipath_sendctrl);
+ dd->ipath_sendctrl);
+ ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+ spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
/*
* We just enabled pioavailupdate, so dma copy is almost certainly
@@ -922,6 +926,7 @@ static noinline void ipath_bad_regread(struct ipath_devdata *dd)
static void handle_layer_pioavail(struct ipath_devdata *dd)
{
+ unsigned long flags;
int ret;
ret = ipath_ib_piobufavail(dd->verbs_dev);
@@ -930,9 +935,12 @@ static void handle_layer_pioavail(struct ipath_devdata *dd)
return;
set:
- set_bit(IPATH_S_PIOINTBUFAVAIL, &dd->ipath_sendctrl);
+ spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
+ dd->ipath_sendctrl |= INFINIPATH_S_PIOINTBUFAVAIL;
ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
dd->ipath_sendctrl);
+ ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+ spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
}
/*
@@ -1168,9 +1176,14 @@ irqreturn_t ipath_intr(int irq, void *data)
handle_urcv(dd, istat);
if (istat & INFINIPATH_I_SPIOBUFAVAIL) {
- clear_bit(IPATH_S_PIOINTBUFAVAIL, &dd->ipath_sendctrl);
+ unsigned long flags;
+
+ spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
+ dd->ipath_sendctrl &= ~INFINIPATH_S_PIOINTBUFAVAIL;
ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
dd->ipath_sendctrl);
+ ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+ spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
handle_layer_pioavail(dd);
}
diff --git a/drivers/infiniband/hw/ipath/ipath_kernel.h b/drivers/infiniband/hw/ipath/ipath_kernel.h
index 728eb39..96553f4 100644
--- a/drivers/infiniband/hw/ipath/ipath_kernel.h
+++ b/drivers/infiniband/hw/ipath/ipath_kernel.h
@@ -376,6 +376,7 @@ struct ipath_devdata {
dma_addr_t *ipath_physshadow;
/* lock to workaround chip bug 9437 */
spinlock_t ipath_tid_lock;
+ spinlock_t ipath_sendctrl_lock;
/*
* IPATH_STATUS_*,
diff --git a/drivers/infiniband/hw/ipath/ipath_ruc.c b/drivers/infiniband/hw/ipath/ipath_ruc.c
index 54c61a9..1b4f7e1 100644
--- a/drivers/infiniband/hw/ipath/ipath_ruc.c
+++ b/drivers/infiniband/hw/ipath/ipath_ruc.c
@@ -479,9 +479,14 @@ done:
static void want_buffer(struct ipath_devdata *dd)
{
- set_bit(IPATH_S_PIOINTBUFAVAIL, &dd->ipath_sendctrl);
+ unsigned long flags;
+
+ spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
+ dd->ipath_sendctrl |= INFINIPATH_S_PIOINTBUFAVAIL;
ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
dd->ipath_sendctrl);
+ ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+ spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
}
/**
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