Re: [PATCH v9 5/5] riscv_cbqri: Add CBQRI capacity allocation platform driver

[Drew Fustini <fustini@kernel.org>]

On Mon, Oct 12, 2026 at 10:33:21PM +0530, Sunil V L wrote:
> On Sat, Oct 3, 2026 at 12:45 PM Drew Fustini <fustini@kernel.org> wrote:
> >
> > Add a platform driver for CBQRI capacity controllers described in
> > device tree with the riscv,cbqri-capacity-controller compatible.
> >
> > The controller node points at the cache it governs with a
> > riscv,cbqri-cache phandle. The driver looks that cache up in cacheinfo
> > and uses its cache id as the resctrl domain id, so the binding does not
> > need to carry a CPU mask. The controller is then handed to the CBQRI
> > core, which probes its capabilities and decides whether to expose it
> > through resctrl.
> >
> > Nothing is vendor-specific and reg is the CBQRI register block itself,
> > so any SoC that describes a CBQRI capacity controller in device tree can
> > use the driver unchanged.
> >
> > Assisted-by: LLM
> > Tested-by: Chen Pei <cp0613@linux.alibaba.com>
> > Signed-off-by: Drew Fustini <fustini@kernel.org>
> > ---
> >  MAINTAINERS                      |   1 +
> >  drivers/resctrl/Kconfig          |  15 +++++
> >  drivers/resctrl/Makefile         |   1 +
> >  drivers/resctrl/cbqri_capacity.c | 127 +++++++++++++++++++++++++++++++++++++++
> >  4 files changed, 144 insertions(+)
[..]
> > diff --git a/drivers/resctrl/cbqri_capacity.c b/drivers/resctrl/cbqri_capacity.c
> > new file mode 100644
> > index 000000000000..0670a676bdb1
> > --- /dev/null
> > +++ b/drivers/resctrl/cbqri_capacity.c
[..]
> > +static int cbqri_capacity_probe(struct platform_device *pdev)
> > +{
> > +       struct device *dev = &pdev->dev;
> > +       struct cbqri_controller_info info = {};
> > +       struct device_node *cache_np;
> > +       struct resource *res;
> > +       u32 rcid_count, cache_level;
> > +       int cache_id, cpu, ret;
> > +
> > +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +       if (!res)
> > +               return -EINVAL;
> > +
> Unless I am missing something, I think you can simplify the code by
> using devm_platform_ioremap_resource().

Yes, I'll switch to devm_platform_get_and_ioremap_resource().

[..]
> > +
> > +       info.type = CBQRI_CONTROLLER_TYPE_CAPACITY;
> > +       info.addr = res->start;
> > +       info.size = resource_size(res);
> > +       info.rcid_count = rcid_count;
> > +       info.cache_id = cache_id;
> > +
> > +       ret = riscv_cbqri_register_cc_dt(&info, cache_level);
> >
> As I mentioned in the comment for another patch, this function doesn't
> need to have "_dt" in its name.

Good point, I'll drop it.

Thanks,
Drew