diff options
| author | Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> | 2024-12-16 19:56:17 +0200 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2025-02-18 15:40:53 -0600 |
| commit | e4728eed24a32f275106c498669a9d3177f9611e (patch) | |
| tree | 0d03fba8b2266204a5322905611e605988c67473 | |
| parent | 2bd0c72117841f7fb82aab7f4a0d65e66ef9543e (diff) | |
PCI: Add pci_resource_num() helper
A few places in PCI code, mainly in setup-bus.c, need to reverse lookup the
index of a resource in pci_dev's resource array. Create pci_resource_num()
helper to avoid repeating the pointer arithmetic trick used to calculate
the index.
Link: https://lore.kernel.org/r/20241216175632.4175-11-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>
| -rw-r--r-- | drivers/pci/pci.h | 24 | ||||
| -rw-r--r-- | drivers/pci/setup-bus.c | 10 |
2 files changed, 28 insertions, 6 deletions
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 89599e63f60c..996185abd30c 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -334,6 +334,28 @@ void pci_walk_bus_locked(struct pci_bus *top, const char *pci_resource_name(struct pci_dev *dev, unsigned int i); +/** + * pci_resource_num - Reverse lookup resource number from device resources + * @dev: PCI device + * @res: Resource to lookup index for (MUST be a @dev's resource) + * + * Perform reverse lookup to determine the resource number for @res within + * @dev resource array. NOTE: The caller is responsible for ensuring @res is + * among @dev's resources! + * + * Returns: resource number. + */ +static inline int pci_resource_num(const struct pci_dev *dev, + const struct resource *res) +{ + int resno = res - &dev->resource[0]; + + /* Passing a resource that is not among dev's resources? */ + WARN_ON_ONCE(resno >= PCI_NUM_RESOURCES); + + return resno; +} + void pci_reassigndev_resource_alignment(struct pci_dev *dev); void pci_disable_bridge_window(struct pci_dev *dev); struct pci_bus *pci_bus_get(struct pci_bus *bus); @@ -693,7 +715,7 @@ unsigned long pci_cardbus_resource_alignment(struct resource *); static inline resource_size_t pci_resource_alignment(struct pci_dev *dev, struct resource *res) { - int resno = res - dev->resource; + int resno = pci_resource_num(dev, res); if (pci_resource_is_iov(resno)) return pci_sriov_resource_alignment(dev, resno); diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index eaeaf09cd91d..524a6381b25b 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -242,7 +242,7 @@ static void reassign_resources_sorted(struct list_head *realloc_head, if (!found_match) /* Just skip */ continue; - idx = res - &add_res->dev->resource[0]; + idx = pci_resource_num(add_res->dev, res); res_name = pci_resource_name(add_res->dev, idx); add_size = add_res->add_size; align = add_res->min_align; @@ -284,7 +284,7 @@ static void assign_requested_resources_sorted(struct list_head *head, list_for_each_entry(dev_res, head, list) { res = dev_res->res; - idx = res - &dev_res->dev->resource[0]; + idx = pci_resource_num(dev_res->dev, res); if (!resource_size(res)) continue; @@ -2210,7 +2210,7 @@ again: res->flags = fail_res->flags; if (pci_is_bridge(fail_res->dev)) { - idx = res - &fail_res->dev->resource[0]; + idx = pci_resource_num(fail_res->dev, res); if (idx >= PCI_BRIDGE_RESOURCES && idx <= PCI_BRIDGE_RESOURCE_END) res->flags = 0; @@ -2294,7 +2294,7 @@ again: res->flags = fail_res->flags; if (pci_is_bridge(fail_res->dev)) { - idx = res - &fail_res->dev->resource[0]; + idx = pci_resource_num(fail_res->dev, res); if (idx >= PCI_BRIDGE_RESOURCES && idx <= PCI_BRIDGE_RESOURCE_END) res->flags = 0; @@ -2401,7 +2401,7 @@ cleanup: struct resource *res = dev_res->res; bridge = dev_res->dev; - i = res - bridge->resource; + i = pci_resource_num(bridge, res); res->start = dev_res->start; res->end = dev_res->end; |