Re: [RFC PATCH 11/27] acpi: Add KEYP Key Configuration Unit parsing

[Jonathan Cameron <jonathan.cameron@huawei.com>]

On Fri, 19 Sep 2025 07:22:20 -0700
Dan Williams <dan.j.williams@intel.com> wrote:

> From: Dave Jiang <dave.jiang@intel.com>
> 
> Parse the KEYP Key Configuration Units (KCU), to decide the max IDE
> streams supported for each host bridge.
> 
> The KEYP table points to a number of KCU structures that each associates
> with a list of root ports (RP) via segment, bus, and devfn. Sanity check
> the KEYP table, ensure all RPs listed for each KCU are included in one
> host bridge. Then extact the max IDE streams supported to
> pci_host_bridge via pci_ide_init_nr_streams().
> 
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> Co-developed-by: Xu Yilun <yilun.xu@linux.intel.com>
> Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>
> [djbw: todo: find a better place for this than common host-bridge init]
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Generally all this ACPI code looks fine (up to the TODOs Dan has called out)
One trivial thing below

> diff --git a/drivers/acpi/x86/keyp.c b/drivers/acpi/x86/keyp.c
> new file mode 100644
> index 000000000000..99680f1edff7
> --- /dev/null
> +++ b/drivers/acpi/x86/keyp.c

> +static bool keyp_info_match(struct acpi_keyp_rp_info *rp,
> +			    struct keyp_hb_info *hb)
> +{
> +	if (rp->segment != hb->segment)
> +		return false;
> +
> +	if (rp->bus >= hb->bus_start && rp->bus <= hb->bus_end)
> +		return true;
If you are going to not use the simple pattern for matching that
would have this inverted so we only match if we pass all checks
might as well do
	return rp->bus >= hb->bus_start && rp->bus <= hb->bus_end;


> +
> +	return false;
> +}