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: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Xiaochun Lee <lixc17@lenovo.com>
This commit is contained in:
Ilpo Järvinen 2024-12-16 19:56:26 +02:00 committed by Bjorn Helgaas
parent 4e362abe48
commit 9caf4ea2fd
3 changed files with 14 additions and 2 deletions

View File

@ -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

View File

@ -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;

View File

@ -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) {