From 991e873223e9bcfaf10a0074eec1507c1ddfb6ab Mon Sep 17 00:00:00 2001 From: Ioana Ciornei Date: Tue, 4 Dec 2018 11:20:29 +0000 Subject: [PATCH] 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: Ioana Ciornei Signed-off-by: Li Yang --- drivers/soc/fsl/dpio/dpio-driver.c | 25 ++++++++++++++++--------- drivers/soc/fsl/dpio/dpio-service.c | 13 +++++++++++++ include/soc/fsl/dpaa2-io.h | 2 ++ 3 files changed, 31 insertions(+), 9 deletions(-) diff --git a/drivers/soc/fsl/dpio/dpio-driver.c b/drivers/soc/fsl/dpio/dpio-driver.c index e58fcc9096e8..832175cac739 100644 --- a/drivers/soc/fsl/dpio/dpio-driver.c +++ b/drivers/soc/fsl/dpio/dpio-driver.c @@ -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); diff --git a/drivers/soc/fsl/dpio/dpio-service.c b/drivers/soc/fsl/dpio/dpio-service.c index ab046f241d32..c02bfb18a1f0 100644 --- a/drivers/soc/fsl/dpio/dpio-service.c +++ b/drivers/soc/fsl/dpio/dpio-service.c @@ -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. diff --git a/include/soc/fsl/dpaa2-io.h b/include/soc/fsl/dpaa2-io.h index 3fbd71c27ba3..243119c53cdf 100644 --- a/include/soc/fsl/dpaa2-io.h +++ b/include/soc/fsl/dpaa2-io.h @@ -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,