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

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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: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
This commit is contained in:
Ioana Ciornei 2018-12-04 11:20:29 +00:00 committed by Li Yang
parent e181a569d8
commit 991e873223
3 changed files with 31 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
drivers/soc/fsl/dpio/dpio-driver.c
View File

@ -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);

13
drivers/soc/fsl/dpio/dpio-service.c
View File

@ -214,6 +214,19 @@ done:
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.

2
include/soc/fsl/dpaa2-io.h
View File

@ -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,