Dan - attached are 2 patches for stable inclusion in kernel versions
3.2, 3.5, and 3.8. The first patch
8a52b9ff1154a68b6a2a8da9a31a87e52f5f6418 (ioatdma: channel reset scheme
fixup on Intel Atom S1200 platforms) is a partial backport sufficient to
allow a clean cherry-pick of the second patch
da87ca4d4ca101f177fffd84f1f0a5e4c0343557 (ioat: fix tasklet tear down).
Please advise if you think this is correct. I should get test results in
http://bugs.launchpad.net/bugs/1291113 sometime soon.
Stable releases 3.11.10.6, 3.12.14, and 3.13.6 are up to date wrt to
da87ca4d4ca101f177fffd84f1f0a5e4c0343557 (ioat: fix tasklet tear down).
rtg
--
Tim Gardner tim.gardner@xxxxxxxxxxxxx
>From e2ff589a895d119146b46ec5579cc51792641218 Mon Sep 17 00:00:00 2001
From: Dave Jiang <dave.jiang@xxxxxxxxx>
Date: Tue, 26 Mar 2013 15:42:47 -0700
Subject: [PATCH 1/2] ioatdma: channel reset scheme fixup on Intel Atom S1200 platforms
BugLink: http://bugs.launchpad.net/bugs/1291113
The Intel Atom S1200 family ioatdma changed the channel reset behavior.
It does a reset similar to PCI FLR by resetting all the MSIX
registers. We have to re-init msix interrupts because of this. This
workaround is only specific to this platform and is not expected to carry
over to the later generations.
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Acked-by: Dan Williams <djbw@xxxxxx>
Signed-off-by: Vinod Koul <vinod.koul@xxxxxxxxx>
(back ported from commit 8a52b9ff1154a68b6a2a8da9a31a87e52f5f6418)
Back port notes: I implemented enough of this patch to support
device->irq_mode storage, upon which da87ca4d4ca101f177fffd84f1f0a5e4c0343557
(ioat: fix tasklet tear down) is dependent.
Signed-off-by: Tim Gardner <tim.gardner@xxxxxxxxxxxxx>
---
drivers/dma/ioat/dma.c | 8 +++++++-
drivers/dma/ioat/dma.h | 10 ++++++++++
2 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c
index 6595180..fe5152a 100644
--- a/drivers/dma/ioat/dma.c
+++ b/drivers/dma/ioat/dma.c
@@ -890,7 +890,7 @@ MODULE_PARM_DESC(ioat_interrupt_style,
* ioat_dma_setup_interrupts - setup interrupt handler
* @device: ioat device
*/
-static int ioat_dma_setup_interrupts(struct ioatdma_device *device)
+int ioat_dma_setup_interrupts(struct ioatdma_device *device)
{
struct ioat_chan_common *chan;
struct pci_dev *pdev = device->pdev;
@@ -939,6 +939,7 @@ msix:
}
}
intrctrl |= IOAT_INTRCTRL_MSIX_VECTOR_CONTROL;
+ device->irq_mode = IOAT_MSIX;
goto done;
msix_single_vector:
@@ -954,6 +955,7 @@ msix_single_vector:
pci_disable_msix(pdev);
goto msi;
}
+ device->irq_mode = IOAT_MSIX_SINGLE;
goto done;
msi:
@@ -967,6 +969,7 @@ msi:
pci_disable_msi(pdev);
goto intx;
}
+ device->irq_mode = IOAT_MSIX;
goto done;
intx:
@@ -975,6 +978,7 @@ intx:
if (err)
goto err_no_irq;
+ device->irq_mode = IOAT_INTX;
done:
if (device->intr_quirk)
device->intr_quirk(device);
@@ -985,9 +989,11 @@ done:
err_no_irq:
/* Disable all interrupt generation */
writeb(0, device->reg_base + IOAT_INTRCTRL_OFFSET);
+ device->irq_mode = IOAT_NOIRQ;
dev_err(dev, "no usable interrupts\n");
return err;
}
+EXPORT_SYMBOL(ioat_dma_setup_interrupts);
static void ioat_disable_interrupts(struct ioatdma_device *device)
{
diff --git a/drivers/dma/ioat/dma.h b/drivers/dma/ioat/dma.h
index 8bebddd..148883e 100644
--- a/drivers/dma/ioat/dma.h
+++ b/drivers/dma/ioat/dma.h
@@ -48,6 +48,14 @@
*/
#define NULL_DESC_BUFFER_SIZE 1
+enum ioat_irq_mode {
+ IOAT_NOIRQ = 0,
+ IOAT_MSIX,
+ IOAT_MSIX_SINGLE,
+ IOAT_MSI,
+ IOAT_INTX
+};
+
/**
* struct ioatdma_device - internal representation of a IOAT device
* @pdev: PCI-Express device
@@ -77,6 +85,7 @@ struct ioatdma_device {
struct msix_entry msix_entries[4];
struct ioat_chan_common *idx[4];
struct dca_provider *dca;
+ enum ioat_irq_mode irq_mode;
void (*intr_quirk)(struct ioatdma_device *device);
int (*enumerate_channels)(struct ioatdma_device *device);
int (*reset_hw)(struct ioat_chan_common *chan);
@@ -344,6 +353,7 @@ bool ioat_cleanup_preamble(struct ioat_chan_common *chan,
dma_addr_t *phys_complete);
void ioat_kobject_add(struct ioatdma_device *device, struct kobj_type *type);
void ioat_kobject_del(struct ioatdma_device *device);
+int ioat_dma_setup_interrupts(struct ioatdma_device *device);
extern const struct sysfs_ops ioat_sysfs_ops;
extern struct ioat_sysfs_entry ioat_version_attr;
extern struct ioat_sysfs_entry ioat_cap_attr;
--
1.7.9.5
>From 48fbb694150ff1ae04d622bfb0771b7e03a068cd Mon Sep 17 00:00:00 2001
From: Dan Williams <dan.j.williams@xxxxxxxxx>
Date: Wed, 19 Feb 2014 16:19:35 -0800
Subject: [PATCH 2/2] ioat: fix tasklet tear down
BugLink: http://bugs.launchpad.net/bugs/1291113
Since commit 77873803363c "net_dma: mark broken" we no longer pin dma
engines active for the network-receive-offload use case. As a result
the ->free_chan_resources() that occurs after the driver self test no
longer has a NET_DMA induced ->alloc_chan_resources() to back it up. A
late firing irq can lead to ksoftirqd spinning indefinitely due to the
tasklet_disable() performed by ->free_chan_resources(). Only
->alloc_chan_resources() can clear this condition in affected kernels.
This problem has been present since commit 3e037454bcfa "I/OAT: Add
support for MSI and MSI-X" in 2.6.24, but is now exposed. Given the
NET_DMA use case is deprecated we can revisit moving the driver to use
threaded irqs. For now, just tear down the irq and tasklet properly by:
1/ Disable the irq from triggering the tasklet
2/ Disable the irq from re-arming
3/ Flush inflight interrupts
4/ Flush the timer
5/ Flush inflight tasklets
References:
https://lkml.org/lkml/2014/1/27/282
https://lkml.org/lkml/2014/2/19/672
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Reported-by: Mike Galbraith <bitbucket@xxxxxxxxx>
Reported-by: Stanislav Fomichev <stfomichev@xxxxxxxxxxxxxx>
Tested-by: Mike Galbraith <bitbucket@xxxxxxxxx>
Tested-by: Stanislav Fomichev <stfomichev@xxxxxxxxxxxxxx>
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
(cherry picked from commit da87ca4d4ca101f177fffd84f1f0a5e4c0343557)
Signed-off-by: Tim Gardner <tim.gardner@xxxxxxxxxxxxx>
---
drivers/dma/ioat/dma.c | 52 +++++++++++++++++++++++++++++++++++++++------
drivers/dma/ioat/dma.h | 1 +
drivers/dma/ioat/dma_v2.c | 11 +++++-----
drivers/dma/ioat/dma_v3.c | 3 +++
4 files changed, 54 insertions(+), 13 deletions(-)
diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c
index fe5152a..1bb65da 100644
--- a/drivers/dma/ioat/dma.c
+++ b/drivers/dma/ioat/dma.c
@@ -75,7 +75,8 @@ static irqreturn_t ioat_dma_do_interrupt(int irq, void *data)
attnstatus = readl(instance->reg_base + IOAT_ATTNSTATUS_OFFSET);
for_each_set_bit(bit, &attnstatus, BITS_PER_LONG) {
chan = ioat_chan_by_index(instance, bit);
- tasklet_schedule(&chan->cleanup_task);
+ if (test_bit(IOAT_RUN, &chan->state))
+ tasklet_schedule(&chan->cleanup_task);
}
writeb(intrctrl, instance->reg_base + IOAT_INTRCTRL_OFFSET);
@@ -91,7 +92,8 @@ static irqreturn_t ioat_dma_do_interrupt_msix(int irq, void *data)
{
struct ioat_chan_common *chan = data;
- tasklet_schedule(&chan->cleanup_task);
+ if (test_bit(IOAT_RUN, &chan->state))
+ tasklet_schedule(&chan->cleanup_task);
return IRQ_HANDLED;
}
@@ -113,7 +115,6 @@ void ioat_init_channel(struct ioatdma_device *device, struct ioat_chan_common *c
chan->timer.function = device->timer_fn;
chan->timer.data = data;
tasklet_init(&chan->cleanup_task, device->cleanup_fn, data);
- tasklet_disable(&chan->cleanup_task);
}
/**
@@ -356,13 +357,49 @@ static int ioat1_dma_alloc_chan_resources(struct dma_chan *c)
writel(((u64) chan->completion_dma) >> 32,
chan->reg_base + IOAT_CHANCMP_OFFSET_HIGH);
- tasklet_enable(&chan->cleanup_task);
+ set_bit(IOAT_RUN, &chan->state);
ioat1_dma_start_null_desc(ioat); /* give chain to dma device */
dev_dbg(to_dev(chan), "%s: allocated %d descriptors\n",
__func__, ioat->desccount);
return ioat->desccount;
}
+void ioat_stop(struct ioat_chan_common *chan)
+{
+ struct ioatdma_device *device = chan->device;
+ struct pci_dev *pdev = device->pdev;
+ int chan_id = chan_num(chan);
+ struct msix_entry *msix;
+
+ /* 1/ stop irq from firing tasklets
+ * 2/ stop the tasklet from re-arming irqs
+ */
+ clear_bit(IOAT_RUN, &chan->state);
+
+ /* flush inflight interrupts */
+ switch (device->irq_mode) {
+ case IOAT_MSIX:
+ msix = &device->msix_entries[chan_id];
+ synchronize_irq(msix->vector);
+ break;
+ case IOAT_MSI:
+ case IOAT_INTX:
+ synchronize_irq(pdev->irq);
+ break;
+ default:
+ break;
+ }
+
+ /* flush inflight timers */
+ del_timer_sync(&chan->timer);
+
+ /* flush inflight tasklet runs */
+ tasklet_kill(&chan->cleanup_task);
+
+ /* final cleanup now that everything is quiesced and can't re-arm */
+ device->cleanup_fn((unsigned long) &chan->common);
+}
+
/**
* ioat1_dma_free_chan_resources - release all the descriptors
* @chan: the channel to be cleaned
@@ -381,9 +418,7 @@ static void ioat1_dma_free_chan_resources(struct dma_chan *c)
if (ioat->desccount == 0)
return;
- tasklet_disable(&chan->cleanup_task);
- del_timer_sync(&chan->timer);
- ioat1_cleanup(ioat);
+ ioat_stop(chan);
/* Delay 100ms after reset to allow internal DMA logic to quiesce
* before removing DMA descriptor resources.
@@ -528,8 +563,11 @@ ioat1_dma_prep_memcpy(struct dma_chan *c, dma_addr_t dma_dest,
static void ioat1_cleanup_event(unsigned long data)
{
struct ioat_dma_chan *ioat = to_ioat_chan((void *) data);
+ struct ioat_chan_common *chan = &ioat->base;
ioat1_cleanup(ioat);
+ if (!test_bit(IOAT_RUN, &chan->state))
+ return;
writew(IOAT_CHANCTRL_RUN, ioat->base.reg_base + IOAT_CHANCTRL_OFFSET);
}
diff --git a/drivers/dma/ioat/dma.h b/drivers/dma/ioat/dma.h
index 148883e..d70124b 100644
--- a/drivers/dma/ioat/dma.h
+++ b/drivers/dma/ioat/dma.h
@@ -354,6 +354,7 @@ bool ioat_cleanup_preamble(struct ioat_chan_common *chan,
void ioat_kobject_add(struct ioatdma_device *device, struct kobj_type *type);
void ioat_kobject_del(struct ioatdma_device *device);
int ioat_dma_setup_interrupts(struct ioatdma_device *device);
+void ioat_stop(struct ioat_chan_common *chan);
extern const struct sysfs_ops ioat_sysfs_ops;
extern struct ioat_sysfs_entry ioat_version_attr;
extern struct ioat_sysfs_entry ioat_cap_attr;
diff --git a/drivers/dma/ioat/dma_v2.c b/drivers/dma/ioat/dma_v2.c
index cb8864d..e60933e 100644
--- a/drivers/dma/ioat/dma_v2.c
+++ b/drivers/dma/ioat/dma_v2.c
@@ -189,8 +189,11 @@ static void ioat2_cleanup(struct ioat2_dma_chan *ioat)
void ioat2_cleanup_event(unsigned long data)
{
struct ioat2_dma_chan *ioat = to_ioat2_chan((void *) data);
+ struct ioat_chan_common *chan = &ioat->base;
ioat2_cleanup(ioat);
+ if (!test_bit(IOAT_RUN, &chan->state))
+ return;
writew(IOAT_CHANCTRL_RUN, ioat->base.reg_base + IOAT_CHANCTRL_OFFSET);
}
@@ -542,10 +545,10 @@ int ioat2_alloc_chan_resources(struct dma_chan *c)
ioat->issued = 0;
ioat->tail = 0;
ioat->alloc_order = order;
+ set_bit(IOAT_RUN, &chan->state);
spin_unlock_bh(&ioat->prep_lock);
spin_unlock_bh(&chan->cleanup_lock);
- tasklet_enable(&chan->cleanup_task);
ioat2_start_null_desc(ioat);
/* check that we got off the ground */
@@ -555,7 +558,6 @@ int ioat2_alloc_chan_resources(struct dma_chan *c)
} while (i++ < 20 && !is_ioat_active(status) && !is_ioat_idle(status));
if (is_ioat_active(status) || is_ioat_idle(status)) {
- set_bit(IOAT_RUN, &chan->state);
return 1 << ioat->alloc_order;
} else {
u32 chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
@@ -798,11 +800,8 @@ void ioat2_free_chan_resources(struct dma_chan *c)
if (!ioat->ring)
return;
- tasklet_disable(&chan->cleanup_task);
- del_timer_sync(&chan->timer);
- device->cleanup_fn((unsigned long) c);
+ ioat_stop(chan);
device->reset_hw(chan);
- clear_bit(IOAT_RUN, &chan->state);
spin_lock_bh(&chan->cleanup_lock);
spin_lock_bh(&ioat->prep_lock);
diff --git a/drivers/dma/ioat/dma_v3.c b/drivers/dma/ioat/dma_v3.c
index 714560f..8680031 100644
--- a/drivers/dma/ioat/dma_v3.c
+++ b/drivers/dma/ioat/dma_v3.c
@@ -325,8 +325,11 @@ static void ioat3_cleanup(struct ioat2_dma_chan *ioat)
static void ioat3_cleanup_event(unsigned long data)
{
struct ioat2_dma_chan *ioat = to_ioat2_chan((void *) data);
+ struct ioat_chan_common *chan = &ioat->base;
ioat3_cleanup(ioat);
+ if (!test_bit(IOAT_RUN, &chan->state))
+ return;
writew(IOAT_CHANCTRL_RUN, ioat->base.reg_base + IOAT_CHANCTRL_OFFSET);
}
--
1.7.9.5