Re: [PATCH 15/24] clocksource/timer-riscv: Refactor riscv_timer_init_dt()

Sunil V L
2023-02-13T17:23:12Z

Hi Conor,

On Thu, Feb 09, 2023 at 08:54:11PM +0000, Conor Dooley wrote:
> Hey Sunil,
>
> On Mon, Jan 30, 2023 at 11:52:16PM +0530, Sunil V L wrote:
> > Refactor the timer init function such that few things can be shared by
> > both DT and ACPI based platforms.
> >
> > Signed-off-by: Anup Patel <apatel@ventanamicro.com>
>
> What did Anup do here? He's not author or co-author, so the SoB chain
> looks incorrect.
>
When I wanted to refactor, I realized Anup had done similar in his branch for
a different purpose. So, I took some of his changes and I added SOB. Let me
add him in co-developed-by:

> > Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
> > ---
> > drivers/clocksource/timer-riscv.c | 79 +++++++++++++++----------------
> > 1 file changed, 37 insertions(+), 42 deletions(-)
> >
> > diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
> > index 1b4b36df5484..4016c065a01c 100644
> > --- a/drivers/clocksource/timer-riscv.c
> > +++ b/drivers/clocksource/timer-riscv.c
> > @@ -119,61 +119,28 @@ static irqreturn_t riscv_timer_interrupt(int irq, void *dev_id)
> > return IRQ_HANDLED;
> > }
> >
> > -static int __init riscv_timer_init_dt(struct device_node *n)
> > +static int __init riscv_timer_init_common(void)
> > {
> > - int cpuid, error;
> > - unsigned long hartid;
> > - struct device_node *child;
> > - struct irq_domain *domain;
> > -
> > - error = riscv_of_processor_hartid(n, &hartid);
> > - if (error < 0) {
> > - pr_warn("Not valid hartid for node [%pOF] error = [%lu]\n",
> > - n, hartid);
> > - return error;
> > - }
> > -
> > - cpuid = riscv_hartid_to_cpuid(hartid);
> > - if (cpuid < 0) {
> > - pr_warn("Invalid cpuid for hartid [%lu]\n", hartid);
> > - return cpuid;
> > - }
> > -
> > - if (cpuid != smp_processor_id())
> > - return 0;
> > + int error;
> > + struct fwnode_handle *intc_fwnode = riscv_get_intc_hwnode();
> > + struct irq_domain *domain = NULL;
> >
> > - child = of_find_compatible_node(NULL, NULL, "riscv,timer");
> > - if (child) {
> > - riscv_timer_cannot_wake_cpu = of_property_read_bool(child,
> > - "riscv,timer-cannot-wake-cpu");
> > - of_node_put(child);
> > - }
>
> Uhh, where did this code go?
> Unless I've badly missed something, this has vanished in the patch.
>
Oops! Anup's patch had moved this to a separate DT timer node instead of
cpu node which I didn't realize. Thanks for catching this. Will fix it.

> >
> > - domain = NULL;
> > - child = of_get_compatible_child(n, "riscv,cpu-intc");
> > - if (!child) {
> > - pr_err("Failed to find INTC node [%pOF]\n", n);
> > - return -ENODEV;
> > - }
> > - domain = irq_find_host(child);
> > - of_node_put(child);
> > + domain = irq_find_matching_fwnode(intc_fwnode, DOMAIN_BUS_ANY);
> > if (!domain) {
> > - pr_err("Failed to find IRQ domain for node [%pOF]\n", n);
> > + pr_err("Failed to find INTC node [%pfwP]\n", intc_fwnode);
> > return -ENODEV;
> > }
> >
> > riscv_clock_event_irq = irq_create_mapping(domain, RV_IRQ_TIMER);
> > if (!riscv_clock_event_irq) {
> > - pr_err("Failed to map timer interrupt for node [%pOF]\n", n);
> > - return -ENODEV;
> > + pr_err("Failed to map timer interrupt for node [%pfwP]\n",
> > + intc_fwnode);
> > }
> >
> > - pr_info("%s: Registering clocksource cpuid [%d] hartid [%lu]\n",
> > - __func__, cpuid, hartid);
> > error = clocksource_register_hz(&riscv_clocksource, riscv_timebase);
> > if (error) {
> > - pr_err("RISCV timer register failed [%d] for cpu = [%d]\n",
> > - error, cpuid);
> > + pr_err("clocksource register failed [%d]\n", error);
>
> If you're changing this, s/register/registration/ to be grammatically
> correct I suppose.
>
Sure.
> > return error;
> > }
> >
> > @@ -199,7 +166,35 @@ static int __init riscv_timer_init_dt(struct device_node *n)
> > static_branch_enable(&riscv_sstc_available);
> > }
> >
> > + pr_info("timer registered using %s\n",
> > + (static_branch_likely(&riscv_sstc_available)) ?
> > + "RISC-V Sstc" : "RISC-V SBI");
>
> Why is this needed? Isn't there a print like 3 lines above here that
> says "Timer interrupt in S-mode is available via sstc extension"?
>
Yes, will remove it.

> > +
> > return error;
> > }
> >
> > +static int __init riscv_timer_init_dt(struct device_node *n)
> > +{
> > + int cpuid, error;
> > + unsigned long hartid;
> > +
> > + error = riscv_of_processor_hartid(n, &hartid);
> > + if (error < 0) {
> > + pr_warn("Not valid hartid for node [%pOF] error = [%lu]\n",
>
> While you're already moving this, may as well fix the grammar IMO.
> s/Not valid/Invalid/
>
Okay

Thanks!
Sunil