We're about to add a Thunderbolt port service in pcie/portdrv_core.c,
allow runtime PM for Thunderbolt ports on Macs in pcie/portdrv_pci.c
and allow power state D3 for Thunderbolt ports in pci.c. In each case
we need to uniquely identify if a PCI device belongs to a Thunderbolt
controller.
We also have the need to detect presence of a Thunderbolt controller in
drivers/platform/x86/apple-gmux.c because dual GPU MacBook Pros cannot
switch external DP/HDMI ports between GPUs if they have Thunderbolt.
Intel uses a Vendor-Specific Extended Capability (VSEC) with ID 0x1234
on all Thunderbolt devices which allows us to recognize them.
Detect presence of this VSEC on device probe and cache it in a newly
added is_thunderbolt bit in struct pci_dev which can then be queried by
pci.c, portdrv, apple-gmux and possibly others.
Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx>
---
drivers/pci/pci.h | 2 ++
drivers/pci/probe.c | 17 +++++++++++++++++
include/linux/pci.h | 1 +
3 files changed, 20 insertions(+)
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 9730c47..14ceed7 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -6,6 +6,8 @@
#define PCI_FIND_CAP_TTL 48
+#define PCI_VSEC_ID_INTEL_TBT 0x1234 /* Thunderbolt */
+
extern const unsigned char pcie_link_speed[];
bool pcie_cap_has_lnkctl(const struct pci_dev *dev);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index ae7daeb..57f175e 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1078,6 +1078,20 @@ void set_pcie_hotplug_bridge(struct pci_dev *pdev)
pdev->is_hotplug_bridge = 1;
}
+static void parse_pcie_vendor_specific_caps(struct pci_dev *dev)
+{
+ int vsec = 0;
+ u32 header;
+
+ while ((vsec = pci_find_next_ext_capability(dev, vsec,
+ PCI_EXT_CAP_ID_VNDR))) {
+ pci_read_config_dword(dev, vsec + PCI_VNDR_HEADER, &header);
+ if (dev->vendor == PCI_VENDOR_ID_INTEL &&
+ PCI_VNDR_HEADER_ID(header) == PCI_VSEC_ID_INTEL_TBT)
+ dev->is_thunderbolt = 1;
+ }
+}
+
/**
* pci_ext_cfg_is_aliased - is ext config space just an alias of std config?
* @dev: PCI device
@@ -1230,6 +1244,9 @@ int pci_setup_device(struct pci_dev *dev)
/* need to have dev->class ready */
dev->cfg_size = pci_cfg_space_size(dev);
+ /* need to have dev->cfg_size ready */
+ parse_pcie_vendor_specific_caps(dev);
+
/* "Unknown power state" */
dev->current_state = PCI_UNKNOWN;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 7081db3f..267564d 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -346,6 +346,7 @@ struct pci_dev {
unsigned int is_virtfn:1;
unsigned int reset_fn:1;
unsigned int is_hotplug_bridge:1;
+ unsigned int is_thunderbolt:1;
unsigned int __aer_firmware_first_valid:1;
unsigned int __aer_firmware_first:1;
unsigned int broken_intx_masking:1;
--
2.8.1
--
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