[PATCH v6 8/8] riscv_cbqri: Add CBQRI capacity allocation platform driver

[Drew Fustini]

On Thu, Jul 30, 2026 at 01:21:24AM +0000, sashiko-bot at kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Medium] The probe function unconditionally fails if the `riscv,cbqri-rcid` device tree property is missing, which breaks support for monitoring-only capacity controllers.
> --
> 
> --- Patch [8]: [PATCH v6 8/8] riscv_cbqri: Add CBQRI capacity allocation platform driver ---
> commit 954af62b51bb07d376a8671fb6db032a2ae482bc
> Author: Drew Fustini <fustini at kernel.org>
> 
> riscv_cbqri: Add CBQRI capacity allocation platform driver
> 
> This commit adds a device-tree platform driver for the RISC-V CBQRI capacity
> controller. It binds to the "riscv,cbqri-capacity-controller" compatible,
> determines the cache domain, and registers the controller with the resctrl
> framework.
> 
> > diff --git a/drivers/resctrl/cbqri_capacity.c b/drivers/resctrl/cbqri_capacity.c
> > new file mode 100644
> > index 0000000000000..0670a676bdb1f
> > --- /dev/null
> > +++ b/drivers/resctrl/cbqri_capacity.c
> [ ... ]
> > +static int cbqri_capacity_probe(struct platform_device *pdev)
> > +{
> [ ... ]
> > +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +	if (!res)
> > +		return -EINVAL;
> > +
> > +	ret = of_property_read_u32(dev->of_node, "riscv,cbqri-rcid", &rcid_count);
> > +	if (ret) {
> > +		dev_err(dev, "missing riscv,cbqri-rcid\n");
> > +		return ret;
> > +	}
> 
> [Severity: Medium]
> Will this unconditionally failing check prevent monitoring-only controllers
> from probing?
> 
> The core registration logic in riscv_cbqri_register_cc_dt() indicates that
> monitoring-only controllers do not need an RCID count.
> 
> However, by returning an error when the riscv,cbqri-rcid property is absent,
> the driver appears to reject valid monitoring-only controllers before they
> can be registered.
> 
> Would it be better to treat this property as optional and default rcid_count
> to 0 if it is missing?

This series only implements allocation, so there is no monitoring-only
controller to describe yet.

Drew