Re: [PATCH V2 4/4] irq: imx: irqsteer: add multi output interrupts support

Lucas Stach
2019-01-30T13:32:25Z

Am Mittwoch, den 30.01.2019, 13:06 +0000 schrieb Aisheng Dong:
> One irqsteer channel can support up to 8 output interrupts.
>
> > Cc: Marc Zyngier <marc.zyngier@arm.com>
> > Cc: Lucas Stach <l.stach@pengutronix.de>
> > Cc: Shawn Guo <shawnguo@kernel.org>
> > Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
> ---
> ChangeLog:
> v1->v2:
>  * calculate irq_count by fsl,num-irqs instead of parsing interrupts
>    property from devicetree to match the input interrupts and outputs
>  * improve output interrupt handler by searching only two registers
>    withint the same group
> ---
>  drivers/irqchip/irq-imx-irqsteer.c | 76 +++++++++++++++++++++++++++++---------
>  1 file changed, 59 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/irqchip/irq-imx-irqsteer.c b/drivers/irqchip/irq-imx-irqsteer.c
> index 67ed862..cc40039 100644
> --- a/drivers/irqchip/irq-imx-irqsteer.c
> +++ b/drivers/irqchip/irq-imx-irqsteer.c
> @@ -10,6 +10,7 @@
>  #include <linux/irqchip/chained_irq.h>
>  #include <linux/irqdomain.h>
>  #include <linux/kernel.h>
> +#include <linux/of_irq.h>
>  #include <linux/of_platform.h>
>  #include <linux/spinlock.h>
>
> @@ -21,10 +22,13 @@
> >  #define CHAN_MINTDIS(t) (CTRL_STRIDE_OFF(t, 3) + 0x4)
> >  #define CHAN_MASTRSTAT(t) (CTRL_STRIDE_OFF(t, 3) + 0x8)
>
> > +#define CHAN_MAX_OUTPUT_INT 0x8
> +
>  struct irqsteer_data {
> > >   void __iomem *regs;
> > >   struct clk *ipg_clk;
> > > - int irq;
> > > + int irq[CHAN_MAX_OUTPUT_INT];
> > > + int irq_count;
> > >   raw_spinlock_t lock;
> > >   int reg_num;
> > >   int channel;
> @@ -87,26 +91,45 @@ static const struct irq_domain_ops imx_irqsteer_domain_ops = {
> > >   .xlate = irq_domain_xlate_onecell,
>  };
>
> +static int imx_irqsteer_get_hwirq_base(struct irqsteer_data *data, u32 irq)
> +{
> > + int i;
> +
> > + for (i = 0; i < data->irq_count; i++) {
> > + if (data->irq[i] == irq)
> + break;

return i * 64; here...
> + }
> +
> + return i * 64;

... and -EINVAL or something here, so we don't return a out of bounds
hwirq base if the loop ever doesn't match something?

> +}
> +
>  static void imx_irqsteer_irq_handler(struct irq_desc *desc)
>  {
> >   struct irqsteer_data *data = irq_desc_get_handler_data(desc);
> > + int hwirq;
> >   int i;
>
> >   chained_irq_enter(irq_desc_get_chip(desc), desc);
>
> > - for (i = 0; i < data->reg_num * 32; i += 32) {
> > - int idx = imx_irqsteer_get_reg_index(data, i);
> > + hwirq = imx_irqsteer_get_hwirq_base(data, irq_desc_get_irq(desc));
> +
> > + for (i = 0; i < 2; i++) {
> > + int idx = imx_irqsteer_get_reg_index(data, hwirq);
> >   unsigned long irqmap;
> >   int pos, virq;
>
> > + if (hwirq >= data->reg_num * 32)
> > + break;
> +
> >   irqmap = readl_relaxed(data->regs +
> >          CHANSTATUS(idx, data->reg_num));
>
> >   for_each_set_bit(pos, &irqmap, 32) {
> > - virq = irq_find_mapping(data->domain, pos + i);
> + virq = irq_find_mapping(data->domain, pos + hwirq);

The irq index calculation need to be "pos + i * 32 + hwirq", otherwise
this will map to the wrong virqs for the second register in each group.

>   if (virq)
> >   generic_handle_irq(virq);
> >   }
> + hwirq += 32;

Could be folded into the loop head.

>   }
>
> >   chained_irq_exit(irq_desc_get_chip(desc), desc);
> @@ -117,7 +140,8 @@ static int imx_irqsteer_probe(struct platform_device *pdev)
> >   struct device_node *np = pdev->dev.of_node;
> >   struct irqsteer_data *data;
> >   struct resource *res;
> > - int ret;
> > + u32 irqs_num;
> > + int i, ret;
>
> >   data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> >   if (!data)
> @@ -130,12 +154,6 @@ static int imx_irqsteer_probe(struct platform_device *pdev)
> >   return PTR_ERR(data->regs);
> >   }
>
> > - data->irq = platform_get_irq(pdev, 0);
> > - if (data->irq <= 0) {
> > - dev_err(&pdev->dev, "failed to get irq\n");
> > - return -ENODEV;
> > - }
> -
> >   data->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
> >   if (IS_ERR(data->ipg_clk)) {
> >   ret = PTR_ERR(data->ipg_clk);
> @@ -146,11 +164,17 @@ static int imx_irqsteer_probe(struct platform_device *pdev)
>
> >   raw_spin_lock_init(&data->lock);
>
> > - of_property_read_u32(np, "fsl,num-irqs", &data->reg_num);
> > + of_property_read_u32(np, "fsl,num-irqs", &irqs_num);
> >   of_property_read_u32(np, "fsl,channel", &data->channel);
>
> > - /* one register bit map represents 32 input interrupts */
> > - data->reg_num /= 32;
> > + /*
> +  * There is one output irqs for each group of 64 inputs.

"irq", singular.

> +  * One register bit map can represent 32 input interrupts.
> > +  */
> > + data->irq_count = irqs_num / 64;
> > + if (irqs_num % 64)
> + data->irq_count += 1;

This is a weird way of writing DIV_ROUND_UP.

> + data->reg_num = irqs_num / 32;
>
> >   if (IS_ENABLED(CONFIG_PM_SLEEP)) {
> >   data->saved_reg = devm_kzalloc(&pdev->dev,
> @@ -177,8 +201,22 @@ static int imx_irqsteer_probe(struct platform_device *pdev)
> >   return -ENOMEM;
> >   }
>
> > - irq_set_chained_handler_and_data(data->irq, imx_irqsteer_irq_handler,
> > -  data);
> > + if (!data->irq_count || data->irq_count > CHAN_MAX_OUTPUT_INT) {
> > + clk_disable_unprepare(data->ipg_clk);
> > + return -EINVAL;
> > + }
> +
> > + for (i = 0; i < data->irq_count; i++) {
> > + data->irq[i] = irq_of_parse_and_map(np, i);
> > + if (!data->irq[i]) {
> > + clk_disable_unprepare(data->ipg_clk);
> + return -EINVAL;

With a lot of failure paths now replicating the clk_disable_unprepare,
return error, I think this warrants a common cleanup path that all
those paths could reach via simple goto.

> + }
> +
> > + irq_set_chained_handler_and_data(data->irq[i],
> > +  imx_irqsteer_irq_handler,
> > +  data);
> > + }
>
> >   platform_set_drvdata(pdev, data);
>
> @@ -188,8 +226,12 @@ static int imx_irqsteer_probe(struct platform_device *pdev)
>  static int imx_irqsteer_remove(struct platform_device *pdev)
>  {
> >   struct irqsteer_data *irqsteer_data = platform_get_drvdata(pdev);
> > + int i;
> +
> > + for (i = 0; i < irqsteer_data->irq_count; i++)
> > + irq_set_chained_handler_and_data(irqsteer_data->irq[i],
> > +  NULL, NULL);
>
> > - irq_set_chained_handler_and_data(irqsteer_data->irq, NULL, NULL);
> >   irq_domain_remove(irqsteer_data->domain);
>
> >   clk_disable_unprepare(irqsteer_data->ipg_clk);