Commit 9caf4ea2 authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by Bjorn Helgaas
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PCI: Extend enable to check for any optional resource 

pci_enable_resources() checks if device's io and mem resources are all
assigned and disallows enable if any resource failed to assign (*) but
makes an exception for the case of disabled extension ROM. There are other
optional resources, however.

Add pci_resource_is_optional() and use it instead of
pci_resource_is_disabled_rom() to cover also IOV resources that are also
optional as per pbus_size_mem().

As there will be more users of pci_resource_is_optional() inside
setup-bus.c in changes coming up after this one, the function is placed
there.

(*) In practice, resource fitting code calls reset_resource() for any
resource it fails to assign which clears resource's ->flags causing
pci_enable_resources() to never detect failed resource assignments.
This seems undesirable internal logic inconsistency, effectively
reset_resource() prevents pci_enable_resources() from functioning as
intended. This is one step of many that will be needed towards removing
reset_resource().

Link: https://lore.kernel.org/r/20241216175632.4175-20-ilpo.jarvinen@linux.intel.com


Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Tested-by: default avatarXiaochun Lee <lixc17@lenovo.com>
parent 4e362abe

drivers/pci/pci.h

+1 −0
Original line number Diff line number Diff line
@@ -333,6 +333,7 @@ void pci_walk_bus_locked(struct pci_bus *top, 
			 void *userdata);



const char *pci_resource_name(struct pci_dev *dev, unsigned int i);

bool pci_resource_is_optional(const struct pci_dev *dev, int resno);



/**

 * pci_resource_num - Reverse lookup resource number from device resources

drivers/pci/setup-bus.c

+12 −0
Original line number Diff line number Diff line
@@ -206,6 +206,18 @@ static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head) 
	}

}



bool pci_resource_is_optional(const struct pci_dev *dev, int resno)

{

	const struct resource *res = pci_resource_n(dev, resno);



	if (pci_resource_is_iov(resno))

		return true;

	if (resno == PCI_ROM_RESOURCE && !(res->flags & IORESOURCE_ROM_ENABLE))

		return true;



	return false;

}



static inline void reset_resource(struct resource *res)

{

	res->start = 0;

drivers/pci/setup-res.c

+1 −2
Original line number Diff line number Diff line
@@ -494,8 +494,7 @@ int pci_enable_resources(struct pci_dev *dev, int mask) 


		if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))

			continue;

		if ((i == PCI_ROM_RESOURCE) &&

				(!(r->flags & IORESOURCE_ROM_ENABLE)))

		if (pci_resource_is_optional(dev, i))

			continue;



		if (r->flags & IORESOURCE_UNSET) {