Re: [PATCH 2/2] dmaengine: idxd: track enabled workqueues in bitmap

[Dave Jiang]

On 9/28/2022 8:21 AM, Jerry Snitselaar wrote:
> On Mon, Sep 19, 2022 at 02:55:53PM -0700, Jerry Snitselaar wrote:
> > Now that idxd_wq_disable_cleanup() sets the workqueue state to
> > IDXD_WQ_DISABLED, use a bitmap to track which workqueues have been
> > enabled. This will then be used to determine which workqueues
> > should be re-enabled when attempting a software reset to recover
> > from a device halt state.
> >
> > Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
> > Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
> > Cc: Vinod Koul <vkoul@xxxxxxxxxx>
> > Signed-off-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
> > ---
> >   drivers/dma/idxd/device.c | 2 ++
> >   drivers/dma/idxd/idxd.h   | 2 ++
> >   drivers/dma/idxd/init.c   | 6 ++++++
> >   drivers/dma/idxd/irq.c    | 4 ++--
> >   drivers/dma/idxd/sysfs.c  | 1 +
> >   5 files changed, 13 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
> > index 31911e255ac1..f0c7d6d348e3 100644
> > --- a/drivers/dma/idxd/device.c
> > +++ b/drivers/dma/idxd/device.c
> > @@ -196,6 +196,7 @@ int idxd_wq_enable(struct idxd_wq *wq)
> >   	}
> >   
> >   	wq->state = IDXD_WQ_ENABLED;
> > +	set_bit(wq->id, idxd->wq_enable_map);
> >   	dev_dbg(dev, "WQ %d enabled\n", wq->id);
> >   	return 0;
> >   }
> > @@ -223,6 +224,7 @@ int idxd_wq_disable(struct idxd_wq *wq, bool reset_config)
> >   
> >   	if (reset_config)
> >   		idxd_wq_disable_cleanup(wq);
> > +	clear_bit(wq->id, idxd->wq_enable_map);
> >   	wq->state = IDXD_WQ_DISABLED;
> >   	dev_dbg(dev, "WQ %d disabled\n", wq->id);
> >   	return 0;
> > diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
> > index fed0dfc1eaa8..f527a7f88b92 100644
> > --- a/drivers/dma/idxd/idxd.h
> > +++ b/drivers/dma/idxd/idxd.h
> > @@ -11,6 +11,7 @@
> >   #include <linux/idr.h>
> >   #include <linux/pci.h>
> >   #include <linux/ioasid.h>
> > +#include <linux/bitmap.h>
> >   #include <linux/perf_event.h>
> >   #include <uapi/linux/idxd.h>
> >   #include "registers.h"
> > @@ -299,6 +300,7 @@ struct idxd_device {
> >   	int rdbuf_limit;
> >   	int nr_rdbufs;		/* non-reserved read buffers */
> >   	unsigned int wqcfg_size;
> > +	unsigned long *wq_enable_map;
> >   
> >   	union sw_err_reg sw_err;
> >   	wait_queue_head_t cmd_waitq;
> > diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
> > index aa3478257ddb..7e27e69ff741 100644
> > --- a/drivers/dma/idxd/init.c
> > +++ b/drivers/dma/idxd/init.c
> > @@ -151,6 +151,12 @@ static int idxd_setup_wqs(struct idxd_device *idxd)
> >   	if (!idxd->wqs)
> >   		return -ENOMEM;
> >   
> > +	idxd->wq_enable_map = bitmap_zalloc_node(idxd->max_wqs, GFP_KERNEL, dev_to_node(dev));
> > +	if (!idxd->wq_enable_map) {
> > +		kfree(idxd->wqs);
> > +		return -ENOMEM;
> > +	}
> > +
> >   	for (i = 0; i < idxd->max_wqs; i++) {
> >   		wq = kzalloc_node(sizeof(*wq), GFP_KERNEL, dev_to_node(dev));
> >   		if (!wq) {
> > diff --git a/drivers/dma/idxd/irq.c b/drivers/dma/idxd/irq.c
> > index 743ead5ebc57..8efaf137fc65 100644
> > --- a/drivers/dma/idxd/irq.c
> > +++ b/drivers/dma/idxd/irq.c
> > @@ -49,9 +49,9 @@ static void idxd_device_reinit(struct work_struct *work)
> >   		goto out;
> >   
> >   	for (i = 0; i < idxd->max_wqs; i++) {
> > -		struct idxd_wq *wq = idxd->wqs[i];
> > +		if (test_bit(i, idxd->wq_enable_map)) {
> > +			struct idxd_wq *wq = idxd->wqs[i];
> >   
> > -		if (wq->state == IDXD_WQ_ENABLED) {
> >   			rc = idxd_wq_enable(wq);
> >   			if (rc < 0) {
> >   				dev_warn(dev, "Unable to re-enable wq %s\n",
> Hi Dave and Fenghua,
>
> Thinking about this last night, this should probably clear the bit here in
> the case where an error is returned from idxd_wq_enable here, yes? I can
> send a v2.
Ah yeah I think so. We failed to enable, so just give up. Thanks.
> > diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
> > index 3f262a57441b..3325b16ed959 100644
> > --- a/drivers/dma/idxd/sysfs.c
> > +++ b/drivers/dma/idxd/sysfs.c
> > @@ -1405,6 +1405,7 @@ static void idxd_conf_device_release(struct device *dev)
> >   	struct idxd_device *idxd = confdev_to_idxd(dev);
> >   
> >   	kfree(idxd->groups);
> > +	bitmap_free(idxd->wq_enable_map);
> >   	kfree(idxd->wqs);
> >   	kfree(idxd->engines);
> >   	ida_free(&idxd_ida, idxd->id);
> > --
> > 2.37.2