linux-kernel - Re: [PATCH 06/16] x86/amd_nb: Simplify root device search

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Message-ID: <20241031152944.GA1511886@yaz-khff2.amd.com>
Date: Thu, 31 Oct 2024 11:29:44 -0400
From: Yazen Ghannam <yazen.ghannam@....com>
To: Borislav Petkov <bp@...en8.de>
Cc: linux-edac@...r.kernel.org, linux-kernel@...r.kernel.org,
	tony.luck@...el.com, x86@...nel.org, avadhut.naik@....com,
	john.allen@....com, mario.limonciello@....com, bhelgaas@...gle.com,
	Shyam-sundar.S-k@....com, richard.gong@....com, jdelvare@...e.com,
	linux@...ck-us.net, clemens@...isch.de, hdegoede@...hat.com,
	ilpo.jarvinen@...ux.intel.com, linux-pci@...r.kernel.org,
	linux-hwmon@...r.kernel.org, platform-driver-x86@...r.kernel.org,
	naveenkrishna.chatradhi@....com, carlos.bilbao.osdev@...il.com
Subject: Re: [PATCH 06/16] x86/amd_nb: Simplify root device search

On Thu, Oct 31, 2024 at 12:20:27PM +0100, Borislav Petkov wrote:
> On Wed, Oct 23, 2024 at 05:21:40PM +0000, Yazen Ghannam wrote:
> > The "root" device search was introduced to support SMN access for Zen
> > systems. This device represents a PCIe root complex. It is not the
> > same as the "CPU/node" devices found at slots 0x18-0x1F.
> > 
> > There may be multiple PCIe root complexes within an AMD node. Such is
> > the case with server or HEDT systems, etc. Therefore it is not enough to
> 
> HEDT?
>

Sorry, forgot to spell it: High-end Desktop.

> ...
> 
> > +struct pci_dev *amd_node_get_root(u16 node)
> > +{
> > +	struct pci_dev *df_f0 __free(pci_dev_put) = NULL;
> > +	struct pci_dev *root;
> > +	u16 cntl_off;
> > +	u8 bus;
> > +
> > +	if (!boot_cpu_has(X86_FEATURE_ZEN))
> 
> check_for_deprecated_apis: WARNING: arch/x86/kernel/amd_node.c:67: Do not use boot_cpu_has() - use cpu_feature_enabled() instead
>

Ack.

Thanks,
Yazen