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

Dong Aisheng
2019-01-30T14:03:44Z

On Wed, Jan 30, 2019 at 9:33 PM Lucas Stach <l.stach@pengutronix.de> wrote:
>
> 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?
>

Good suggestion, will add it.

> > +}
> > +
> > 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.
>

For second register map, hwirq will plus 32 in next round.
So i can't see this will map a wrong virqs.
And it looks to me ""pos + i * 32 + hwirq" is equal to "hwirq + 32".
Am i missed something?

> > if (virq)
> > > generic_handle_irq(virq);
> > > }
> > + hwirq += 32;
>
> Could be folded into the loop head.
>

You mean “for (i = 0; i < 2; i++, hwirq +=32)” ?
I feel that's not quite necessary.

> > }
> >
> > > 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.
>

Got it

> > + * 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.
>

Good suggestion

> > + 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.
>

Sound goods to me

Regards
Dong Aisheng

> > + }
> > +
> > > + 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);