Re: [PATCH RFC 7/9] powerpc/pseries: Enable HVPIPE event message interrupt

[Haren Myneni <haren@linux.ibm.com>]

On Thu, 2025-07-03 at 09:00 +0200, Krzysztof Kozlowski wrote:
> On 03/07/2025 00:14, Haren Myneni wrote:
> > +static int __init enable_hvpipe_IRQ(void)
> > +{
> > +	struct device_node *np;
> > +
> > +	hvpipe_check_exception_token =
> > rtas_function_token(RTAS_FN_CHECK_EXCEPTION);
> > +	if (hvpipe_check_exception_token  == RTAS_UNKNOWN_SERVICE)
> > +		return -ENODEV;
> > +
> > +	/* hvpipe events */
> > +	np = of_find_node_by_path("/event-sources/ibm,hvpipe-msg-
> > events");
> 
> Undocumented ABI, NAK. Plus node names should not be used at all as
> ABI... and naming does not follow DT spec/style, not sure if you care
> about it, though.

These new interfaces are documented in new version of PAPR. Please note
that /proc/device-tree/event-sources node is different which will not
have ibm,phandle unlike in some other node. event-sources already has
several event messages such as io, EPOW, hot-plug, internal-errors
events and adding hvpipe-msg events now. We can see the similar
of_find_node_by_path() usage in the current code.

io_event_irq.c:	np = of_find_node_by_path("/event-sources/ibm,io-
events");
ras.c:	np = of_find_node_by_path("/event-sources/hot-plug-events");
ras.c	np = of_find_node_by_path("/event-sources/internal-errors");
ras.c:	np = of_find_node_by_path("/event-sources/epow-events");

Thanks
Haren

> 
> 
> > +	if (np != NULL) {
> > +		request_event_sources_irqs(np, hvpipe_event_interrupt,
> > +					"HPIPE_EVENT");
> > +		of_node_put(np);
> > +	} else {
> > +		pr_err("Can not enable hvpipe event IRQ\n");
> 
> Best regards,
> Krzysztof