Commit 472ff48e authored by Alex Williamson's avatar Alex Williamson Committed by Bjorn Helgaas
Browse files

PCI: Fix BUILD_BUG_ON usage for old gcc 

As reported in the below link, it seems older versions of gcc cannot
determine that the howmany variable is known for all callers.  Include
a test so that newer compilers can enforce this sanity check and older
compilers can still work.  Add __always_inline attribute to give the
compiler an even better chance to know the inputs.

Link: https://lore.kernel.org/r/20250212185337.293023-1-alex.williamson@redhat.com


Fixes: 4453f360 ("PCI: Batch BAR sizing operations")
Reported-by: default avatarOleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/all/20250209154512.GA18688@redhat.com


Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Tested-by: default avatarOleg Nesterov <oleg@redhat.com>
Tested-by: default avatarMitchell Augustin <mitchell.augustin@canonical.com>
parent 2014c95a

drivers/pci/probe.c

+3 −2
Original line number Diff line number Diff line
@@ -339,13 +339,14 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, 
	return (res->flags & IORESOURCE_MEM_64) ? 1 : 0;

}



static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom)

static __always_inline void pci_read_bases(struct pci_dev *dev,

					   unsigned int howmany, int rom)

{

	u32 rombar, stdbars[PCI_STD_NUM_BARS];

	unsigned int pos, reg;

	u16 orig_cmd;



	BUILD_BUG_ON(howmany > PCI_STD_NUM_BARS);

	BUILD_BUG_ON(statically_true(howmany > PCI_STD_NUM_BARS));



	if (dev->non_compliant_bars)

		return;