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Commit 991e8732 authored by Ioana Ciornei's avatar Ioana Ciornei Committed by Li Yang
Browse files

soc: fsl: dpio: use a cpumask to identify which cpus are unused 



The current implementation of the dpio driver uses a static next_cpu
variable to keep track of the index of the next cpu available. This
approach does not handle well unbinding and binding dpio devices in a
random order. For example, unbinding a dpio and then binding it again
with the driver, will generate the below error:

$ echo dpio.5 > /sys/bus/fsl-mc/drivers/fsl_mc_dpio/unbind
$ echo dpio.5 > /sys/bus/fsl-mc/drivers/fsl_mc_dpio/bind
[  103.946380] fsl_mc_dpio dpio.5: probe failed. Number of DPIOs exceeds
NR_CPUS.
[  103.955157] fsl_mc_dpio dpio.5: fsl_mc_driver_probe failed: -34
-bash: echo: write error: No such device

Fix this error by keeping a global cpumask of unused cpus that will be
updated at every dpaa2_dpio_[probe,remove].

Signed-off-by: default avatarIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: default avatarLi Yang <leoyang.li@nxp.com>
parent e181a569

drivers/soc/fsl/dpio/dpio-driver.c

+16 −9
Original line number Diff line number Diff line
@@ -30,6 +30,8 @@ struct dpio_priv { 
	struct dpaa2_io *io;

};



static cpumask_var_t cpus_unused_mask;



static irqreturn_t dpio_irq_handler(int irq_num, void *arg)

{

	struct device *dev = (struct device *)arg;
@@ -86,7 +88,7 @@ static int dpaa2_dpio_probe(struct fsl_mc_device *dpio_dev) 
	struct dpio_priv *priv;

	int err = -ENOMEM;

	struct device *dev = &dpio_dev->dev;

	static int next_cpu = -1;

	int possible_next_cpu;



	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);

	if (!priv)
@@ -128,17 +130,14 @@ static int dpaa2_dpio_probe(struct fsl_mc_device *dpio_dev) 
	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);



	if (!cpu_possible(next_cpu)) {

	possible_next_cpu = cpumask_first(cpus_unused_mask);

	if (possible_next_cpu >= nr_cpu_ids) {

		dev_err(dev, "probe failed. Number of DPIOs exceeds NR_CPUS.\n");

		err = -ERANGE;

		goto err_allocate_irqs;

	}

	desc.cpu = next_cpu;

	desc.cpu = possible_next_cpu;

	cpumask_clear_cpu(possible_next_cpu, cpus_unused_mask);



	/*

	 * Set the CENA regs to be the cache inhibited area of the portal to
@@ -211,7 +210,7 @@ static int dpaa2_dpio_remove(struct fsl_mc_device *dpio_dev) 
{

	struct device *dev;

	struct dpio_priv *priv;

	int err;

	int err = 0, cpu;



	dev = &dpio_dev->dev;

	priv = dev_get_drvdata(dev);
@@ -220,6 +219,9 @@ static int dpaa2_dpio_remove(struct fsl_mc_device *dpio_dev) 


	dpio_teardown_irqs(dpio_dev);



	cpu = dpaa2_io_get_cpu(priv->io);

	cpumask_set_cpu(cpu, cpus_unused_mask);



	err = fsl_mc_portal_allocate(dpio_dev, 0, &dpio_dev->mc_io);

	if (err) {

		dev_err(dev, "MC portal allocation failed\n");
@@ -267,11 +269,16 @@ static struct fsl_mc_driver dpaa2_dpio_driver = { 


static int dpio_driver_init(void)

{

	if (!zalloc_cpumask_var(&cpus_unused_mask, GFP_KERNEL))

		return -ENOMEM;

	cpumask_copy(cpus_unused_mask, cpu_online_mask);



	return fsl_mc_driver_register(&dpaa2_dpio_driver);

}



static void dpio_driver_exit(void)

{

	free_cpumask_var(cpus_unused_mask);

	fsl_mc_driver_unregister(&dpaa2_dpio_driver);

}

module_init(dpio_driver_init);

drivers/soc/fsl/dpio/dpio-service.c

+13 −0
Original line number Diff line number Diff line
@@ -214,6 +214,19 @@ irqreturn_t dpaa2_io_irq(struct dpaa2_io *obj) 
	return IRQ_HANDLED;

}



/**

 * dpaa2_io_get_cpu() - get the cpu associated with a given DPIO object

 *

 * @d: the given DPIO object.

 *

 * Return the cpu associated with the DPIO object

 */

int dpaa2_io_get_cpu(struct dpaa2_io *d)

{

	return d->dpio_desc.cpu;

}

EXPORT_SYMBOL(dpaa2_io_get_cpu);



/**

 * dpaa2_io_service_register() - Prepare for servicing of FQDAN or CDAN

 *                               notifications on the given DPIO service.

include/soc/fsl/dpaa2-io.h

+2 −0
Original line number Diff line number Diff line
@@ -90,6 +90,8 @@ struct dpaa2_io_notification_ctx { 
	void *dpio_private;

};



int dpaa2_io_get_cpu(struct dpaa2_io *d);



int dpaa2_io_service_register(struct dpaa2_io *service,

			      struct dpaa2_io_notification_ctx *ctx);

void dpaa2_io_service_deregister(struct dpaa2_io *service,