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

From: Borislav Petkov
Date: Thu Oct 31 2024 - 07:21:05 EST


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?

...

> +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

> + return NULL;

--
Regards/Gruss,
Boris.

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