Date:   Fri, 4 Nov 2016 15:11:19 +0000
From:   Ruxandra Ioana Radulescu <ruxandra.radulescu@....com>
To:     Stuart Yoder <stuart.yoder@....com>,
        "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>
CC:     German Rivera <german.rivera@....com>,
        "devel@...verdev.osuosl.org" <devel@...verdev.osuosl.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "agraf@...e.de" <agraf@...e.de>, "arnd@...db.de" <arnd@...db.de>,
        Leo Li <leoyang.li@....com>, Roy Pledge <roy.pledge@....com>,
        Haiying Wang <haiying.wang@....com>,
        Stuart Yoder <stuart.yoder@....com>
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@....com>
> Subject: FW: [PATCH 8/9] bus: fsl-mc: dpio: add the DPAA2 DPIO object
> driver
> 
> 
> 
> -----Original Message-----
> From: Stuart Yoder [mailto:stuart.yoder@....com]
> Sent: Friday, October 21, 2016 9:02 AM
> To: gregkh@...uxfoundation.org
> Cc: German Rivera <german.rivera@....com>; devel@...verdev.osuosl.org;
> linux-kernel@...r.kernel.org; agraf@...e.de; arnd@...db.de; Leo Li
> <leoyang.li@....com>; Roy Pledge <roy.pledge@....com>; Haiying Wang
> <haiying.wang@....com>; Stuart Yoder <stuart.yoder@....com>
> Subject: [PATCH 8/9] bus: fsl-mc: dpio: add the DPAA2 DPIO object driver
> 
> From: Roy Pledge <roy.pledge@....com>
> 
> 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@....com>
> Signed-off-by: Haiying Wang <haiying.wang@....com>
> Signed-off-by: Stuart Yoder <stuart.yoder@....com>
> ---
>  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?

Thanks,
Ioana

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