Re: [PATCH v8 25/25] PCI/sysfs: Limit BAR resize attribute scope to platforms with PCI mmap

[sashiko-bot@kernel.org]

> Currently, __resource_resize_store() uses sysfs_remove_groups()
> and sysfs_create_groups() on pci_dev_resource_attr_groups to
> tear down and recreate the resourceN files after a BAR resize,
> so the updated BAR sizes are visible in sysfs.
> 
> The resourceN files only exist on platforms that define
> HAVE_PCI_MMAP or ARCH_GENERIC_PCI_MMAP_RESOURCE.  On platforms
> that define neither, pci_dev_resource_attr_groups is NULL and
> the sysfs_remove_groups() and sysfs_create_groups() calls in
> __resource_resize_store() become no-ops.
> 
> Resizable BAR (ReBAR) is a PCI Express extended capability
> (PCI_EXT_CAP_ID_REBAR) that requires PCIe extended config
> space.  Every PCIe-capable architecture defines HAVE_PCI_MMAP
> or ARCH_GENERIC_PCI_MMAP_RESOURCE (via arch headers or the
> asm-generic/pci.h fallback).  Architectures without either
> only support conventional PCI and cannot have any ReBAR-capable
> devices.
> 
> Thus, move the resize show and store helpers, the per-BAR attribute
> definitions, and the attribute group behind the existing #ifdef
> HAVE_PCI_MMAP || ARCH_GENERIC_PCI_MMAP_RESOURCE guard, and fold the
> group reference in pci_dev_groups[] into the existing #if block.
> 
> Tested-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
> Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260619085200.3729431-1-kwilczynski@kernel.org?part=25