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 <[email protected]> Signed-off-by: Krzysztof Wilczyński <[email protected]> --- drivers/pci/pci-sysfs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index f5427bcfb0cc..6099371f67e7 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -1661,6 +1661,7 @@ static const struct attribute_group pci_dev_reset_method_attr_group = { .is_visible = pci_dev_reset_attr_is_visible, }; +#if defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE) static ssize_t __resource_resize_show(struct device *dev, int n, char *buf) { struct pci_dev *pdev = to_pci_dev(dev); @@ -1775,6 +1776,7 @@ static const struct attribute_group pci_dev_resource_resize_attr_group = { .attrs = resource_resize_attrs, .is_visible = resource_resize_attr_is_visible, }; +#endif static struct attribute *pci_dev_dev_attrs[] = { &dev_attr_boot_vga.attr, @@ -1849,8 +1851,8 @@ const struct attribute_group *pci_dev_groups[] = { &pci_dev_resource_io_attr_group, &pci_dev_resource_uc_attr_group, &pci_dev_resource_wc_attr_group, -#endif &pci_dev_resource_resize_attr_group, +#endif &pci_dev_config_attr_group, &pci_dev_rom_attr_group, &pci_dev_reset_attr_group, -- 2.54.0
