RE: [PATCH 8/9] bus: fsl-mc: dpio: add the DPAA2 DPIO object driver

[Stuart Yoder]

> -----Original Message-----
> From: Ruxandra Ioana Radulescu
> Sent: Friday, November 04, 2016 10:11 AM
> To: Stuart Yoder <stuart.yoder@xxxxxxx>; gregkh@xxxxxxxxxxxxxxxxxxx
> Cc: German Rivera <german.rivera@xxxxxxx>; devel@xxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> agraf@xxxxxxx; arnd@xxxxxxxx; Leo Li <leoyang.li@xxxxxxx>; Roy Pledge <roy.pledge@xxxxxxx>; Haiying Wang
> <haiying.wang@xxxxxxx>; Stuart Yoder <stuart.yoder@xxxxxxx>
> Subject: RE: [PATCH 8/9] bus: fsl-mc: dpio: add the DPAA2 DPIO object driver
> 
> > -----Original Message-----
> > From: Stuart Yoder
> > Sent: Thursday, November 03, 2016 4:38 PM
> > To: Ruxandra Ioana Radulescu <ruxandra.radulescu@xxxxxxx>
> > Subject: FW: [PATCH 8/9] bus: fsl-mc: dpio: add the DPAA2 DPIO object
> > driver
> >
> >
> >
> > -----Original Message-----
> > From: Stuart Yoder [mailto:stuart.yoder@xxxxxxx]
> > Sent: Friday, October 21, 2016 9:02 AM
> > To: gregkh@xxxxxxxxxxxxxxxxxxx
> > Cc: German Rivera <german.rivera@xxxxxxx>; devel@xxxxxxxxxxxxxxxxxxxx;
> > linux-kernel@xxxxxxxxxxxxxxx; agraf@xxxxxxx; arnd@xxxxxxxx; Leo Li
> > <leoyang.li@xxxxxxx>; Roy Pledge <roy.pledge@xxxxxxx>; Haiying Wang
> > <haiying.wang@xxxxxxx>; Stuart Yoder <stuart.yoder@xxxxxxx>
> > Subject: [PATCH 8/9] bus: fsl-mc: dpio: add the DPAA2 DPIO object driver
> >
> > From: Roy Pledge <roy.pledge@xxxxxxx>
> >
> > The DPIO driver registers with the fsl-mc bus to handle bus-related
> > events for DPIO objects.  Key responsibility is mapping I/O
> > regions, setting up interrupt handlers, and calling the DPIO
> > service initialization during probe.
> >
> > Signed-off-by: Roy Pledge <roy.pledge@xxxxxxx>
> > Signed-off-by: Haiying Wang <haiying.wang@xxxxxxx>
> > Signed-off-by: Stuart Yoder <stuart.yoder@xxxxxxx>
> > ---
> >  drivers/bus/fsl-mc/dpio/Makefile      |   2 +-
> >  drivers/bus/fsl-mc/dpio/dpio-driver.c | 289
> > ++++++++++++++++++++++++++++++++++
> >  2 files changed, 290 insertions(+), 1 deletion(-)
> >  create mode 100644 drivers/bus/fsl-mc/dpio/dpio-driver.c
> >
> > diff --git a/drivers/bus/fsl-mc/dpio/Makefile b/drivers/bus/fsl-
> > mc/dpio/Makefile
> > index 0778da7..837d330 100644
> > --- a/drivers/bus/fsl-mc/dpio/Makefile
> > +++ b/drivers/bus/fsl-mc/dpio/Makefile
> > @@ -6,4 +6,4 @@ subdir-ccflags-y := -Werror
> >
> >  obj-$(CONFIG_FSL_MC_DPIO) += fsl-mc-dpio.o
> >
> > -fsl-mc-dpio-objs := dpio.o qbman-portal.o dpio-service.o
> > +fsl-mc-dpio-objs := dpio.o qbman-portal.o dpio-service.o dpio-driver.o
> > diff --git a/drivers/bus/fsl-mc/dpio/dpio-driver.c b/drivers/bus/fsl-
> > mc/dpio/dpio-driver.c
> > new file mode 100644
> > index 0000000..ad04a2c
> > --- /dev/null
> > +++ b/drivers/bus/fsl-mc/dpio/dpio-driver.c
> > @@ -0,0 +1,289 @@
> > +/*
> > + * Copyright 2014-2016 Freescale Semiconductor Inc.
> > + *
> > + * Redistribution and use in source and binary forms, with or without
> > + * modification, are permitted provided that the following conditions are
> > met:
> > + *     * Redistributions of source code must retain the above copyright
> > + *	 notice, this list of conditions and the following disclaimer.
> > + *     * Redistributions in binary form must reproduce the above copyright
> > + *	 notice, this list of conditions and the following disclaimer in the
> > + *	 documentation and/or other materials provided with the
> > distribution.
> > + *     * Neither the name of Freescale Semiconductor nor the
> > + *	 names of its contributors may be used to endorse or promote
> > products
> > + *	 derived from this software without specific prior written permission.
> > + *
> > + * ALTERNATIVELY, this software may be distributed under the terms of the
> > + * GNU General Public License ("GPL") as published by the Free Software
> > + * Foundation, either version 2 of that License or (at your option) any
> > + * later version.
> > + *
> > + * THIS SOFTWARE IS PROVIDED BY Freescale Semiconductor ``AS IS'' AND
> > ANY
> > + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
> > THE IMPLIED
> > + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
> > PURPOSE ARE
> > + * DISCLAIMED. IN NO EVENT SHALL Freescale Semiconductor BE LIABLE FOR
> > ANY
> > + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
> > CONSEQUENTIAL DAMAGES
> > + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
> > GOODS OR SERVICES;
> > + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> > HOWEVER CAUSED AND
> > + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
> > OR TORT
> > + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
> > THE USE OF THIS
> > + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
> > + */
> > +
> > +#include <linux/types.h>
> > +#include <linux/init.h>
> > +#include <linux/module.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/msi.h>
> > +#include <linux/dma-mapping.h>
> > +#include <linux/delay.h>
> > +
> > +#include <linux/fsl/mc.h>
> > +#include <linux/fsl/dpaa2-io.h>
> > +
> > +#include "qbman-portal.h"
> > +#include "dpio.h"
> > +#include "dpio-cmd.h"
> > +
> > +MODULE_LICENSE("Dual BSD/GPL");
> > +MODULE_AUTHOR("Freescale Semiconductor, Inc");
> > +MODULE_DESCRIPTION("DPIO Driver");
> > +
> > +struct dpio_priv {
> > +	struct dpaa2_io *io;
> > +};
> > +
> > +static irqreturn_t dpio_irq_handler(int irq_num, void *arg)
> > +{
> > +	struct device *dev = (struct device *)arg;
> > +	struct dpio_priv *priv = dev_get_drvdata(dev);
> > +
> > +	return dpaa2_io_irq(priv->io);
> > +}
> > +
> > +static void unregister_dpio_irq_handlers(struct fsl_mc_device *dpio_dev)
> > +{
> > +	struct fsl_mc_device_irq *irq;
> > +
> > +	irq = dpio_dev->irqs[0];
> > +
> > +	/* clear the affinity hint */
> > +	irq_set_affinity_hint(irq->msi_desc->irq, NULL);
> > +}
> > +
> > +static int register_dpio_irq_handlers(struct fsl_mc_device *dpio_dev, int
> > cpu)
> > +{
> > +	struct dpio_priv *priv;
> > +	int error;
> > +	struct fsl_mc_device_irq *irq;
> > +	cpumask_t mask;
> > +
> > +	priv = dev_get_drvdata(&dpio_dev->dev);
> > +
> > +	irq = dpio_dev->irqs[0];
> > +	error = devm_request_irq(&dpio_dev->dev,
> > +				 irq->msi_desc->irq,
> > +				 dpio_irq_handler,
> > +				 0,
> > +				 dev_name(&dpio_dev->dev),
> > +				 &dpio_dev->dev);
> > +	if (error < 0) {
> > +		dev_err(&dpio_dev->dev,
> > +			"devm_request_irq() failed: %d\n",
> > +			error);
> > +		return error;
> > +	}
> > +
> > +	/* set the affinity hint */
> > +	cpumask_clear(&mask);
> > +	cpumask_set_cpu(cpu, &mask);
> > +	if (irq_set_affinity_hint(irq->msi_desc->irq, &mask))
> > +		dev_err(&dpio_dev->dev,
> > +		       "irq_set_affinity failed irq %d cpu %d\n",
> > +		       irq->msi_desc->irq, cpu);
> > +
> > +	return 0;
> > +}
> > +
> > +static int dpaa2_dpio_probe(struct fsl_mc_device *dpio_dev)
> > +{
> > +	struct dpio_attr dpio_attrs;
> > +	struct dpaa2_io_desc desc;
> > +	struct dpio_priv *priv;
> > +	int err = -ENOMEM;
> > +	struct device *dev = &dpio_dev->dev;
> > +	static int next_cpu = -1;
> > +
> > +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> > +	if (!priv)
> > +		goto err_priv_alloc;
> > +
> > +	dev_set_drvdata(dev, priv);
> > +
> > +	err = fsl_mc_portal_allocate(dpio_dev, 0, &dpio_dev->mc_io);
> > +	if (err) {
> > +		dev_dbg(dev, "MC portal allocation failed\n");
> > +		err = -EPROBE_DEFER;
> > +		goto err_mcportal;
> > +	}
> > +
> > +	err = dpio_open(dpio_dev->mc_io, 0, dpio_dev->obj_desc.id,
> > +			&dpio_dev->mc_handle);
> > +	if (err) {
> > +		dev_err(dev, "dpio_open() failed\n");
> > +		goto err_open;
> > +	}
> > +
> > +	err = dpio_get_attributes(dpio_dev->mc_io, 0, dpio_dev-
> > >mc_handle,
> > +				  &dpio_attrs);
> > +	if (err) {
> > +		dev_err(dev, "dpio_get_attributes() failed %d\n", err);
> > +		goto err_get_attr;
> > +	}
> > +	desc.qman_version = dpio_attrs.qbman_version;
> > +
> > +	err = dpio_enable(dpio_dev->mc_io, 0, dpio_dev->mc_handle);
> > +	if (err) {
> > +		dev_err(dev, "dpio_enable() failed %d\n", err);
> > +		goto err_get_attr;
> > +	}
> > +
> > +	/* initialize DPIO descriptor */
> > +	desc.receives_notifications = dpio_attrs.num_priorities ? 1 : 0;
> > +	desc.has_8prio = dpio_attrs.num_priorities == 8 ? 1 : 0;
> > +	desc.dpio_id = dpio_dev->obj_desc.id;
> > +
> > +	/* get the cpu to use for the affinity hint */
> > +	if (next_cpu == -1)
> > +		next_cpu = cpumask_first(cpu_online_mask);
> > +	else
> > +		next_cpu = cpumask_next(next_cpu, cpu_online_mask);
> > +	desc.cpu = next_cpu;
> 
> What happens if there's more DPIOs than cores and cpumask_next
> returns nr_cpu_ids?

We need to error out in that case.  DPIO can't handle >= NR_CPUS.

Stuart