From 513d359dad3a99c13846f4e97b372ec98d245695 Mon Sep 17 00:00:00 2001 From: Bill XIE Date: Tue, 2 Aug 2022 22:55:51 +0800 Subject: [PATCH] pci_device: Add a function to find PCI capability ID recursively Some PCI capabilities should only be enabled if it is available not only on a device, but also all bridge upstream of it. Checking only the device and the bridge just above it may not be enough. Signed-off-by: Bill XIE Change-Id: I1237d3b4b86dd0ae5eb586e3c3c407362e6ca291 Reviewed-on: https://review.coreboot.org/c/coreboot/+/66383 Reviewed-by: Arthur Heymans Reviewed-by: Lean Sheng Tan Tested-by: build bot (Jenkins) --- src/device/pci_device.c | 24 ++++++++++++++++++++++++ src/include/device/pci.h | 1 + 2 files changed, 25 insertions(+) diff --git a/src/device/pci_device.c b/src/device/pci_device.c index fda088b020..44c47a7548 100644 --- a/src/device/pci_device.c +++ b/src/device/pci_device.c @@ -6,6 +6,7 @@ */ #include +#include #include #include #include @@ -1298,6 +1299,29 @@ unsigned int pci_match_simple_dev(struct device *dev, pci_devfn_t sdev) dev->path.pci.devfn == PCI_DEV2DEVFN(sdev); } +/** + * Test whether a capability is available along the whole path from the given + * device to the host bridge. + * + * @param dev Pointer to the device structure. + * @param cap PCI_CAP_LIST_ID of the PCI capability we're looking for. + * @return The next matching capability of the given device, if it is available + * along the whole path, or zero if not. + */ +uint16_t pci_find_cap_recursive(const struct device *dev, uint16_t cap) +{ + assert(dev->bus); + uint16_t pos = pci_find_capability(dev, cap); + const struct device *bridge = dev->bus->dev; + while (bridge && (bridge->path.type == DEVICE_PATH_PCI)) { + assert(bridge->bus); + if (!pci_find_capability(bridge, cap)) + return 0; + bridge = bridge->bus->dev; + } + return pos; +} + /** * PCI devices that are marked as "hidden" do not get probed. However, the same * initialization logic is still performed as if it were. This is useful when diff --git a/src/include/device/pci.h b/src/include/device/pci.h index f2e250631e..f28f319d8c 100644 --- a/src/include/device/pci.h +++ b/src/include/device/pci.h @@ -97,6 +97,7 @@ void pci_dev_set_subsystem(struct device *dev, unsigned int vendor, unsigned int device); void pci_dev_init(struct device *dev); unsigned int pci_match_simple_dev(struct device *dev, pci_devfn_t sdev); +uint16_t pci_find_cap_recursive(const struct device *dev, uint16_t cap); const char *pin_to_str(int pin); int get_pci_irq_pins(struct device *dev, struct device **parent_bdg);