All PCIe devices are expected to be able to handle 8-bit tags.
'commit 60db3a4d8cc9 ("PCI: Enable PCIe Extended Tags if supported")'
enabled extended tags for all devices based on the spec direction.
The Broadcom HT2100 seems to be having issues with handling
8-bit tags. Mark it as broken.
If a device with extended tags quirk is found, disable extended tags for
all devices in the tree assuming peer-to-peer is possible.
The pci_walk_bus() in the quirk handles all devices we've already
enumerated, and all devices we'll enumerate in the future are handled in
pci_configure_device().
Reported-by: Wim ten Have <wim.ten.have@xxxxxxxxxx>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1467674
Fixes: 60db3a4d8cc9 ("PCI: Enable PCIe Extended Tags if supported")
Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
---
drivers/pci/pci.h | 1 +
drivers/pci/probe.c | 35 ++++++++++++++++++++++++++++++-----
drivers/pci/quirks.c | 19 +++++++++++++++++++
include/linux/pci.h | 1 +
4 files changed, 51 insertions(+), 5 deletions(-)
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index f8113e5..7153c92 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -239,6 +239,7 @@ enum pci_bar_type {
pci_bar_mem64, /* A 64-bit memory BAR */
};
+int pci_configure_extended_tags(struct pci_dev *dev, void *ign);
bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl,
int crs_timeout);
int pci_setup_device(struct pci_dev *dev);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 19c8950..bc067fb 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1684,22 +1684,47 @@ static void program_hpp_type2(struct pci_dev *dev, struct hpp_type2 *hpp)
*/
}
-static void pci_configure_extended_tags(struct pci_dev *dev)
+int pci_configure_extended_tags(struct pci_dev *dev, void *ign)
{
+ struct pci_host_bridge *host;
u32 dev_cap;
int ret;
+ u16 ctl;
if (!pci_is_pcie(dev))
- return;
+ return 0;
ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &dev_cap);
if (ret)
- return;
+ return 0;
+
+ if (!(dev_cap & PCI_EXP_DEVCAP_EXT_TAG))
+ return 0;
+
+ ret = pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
+ if (ret)
+ return 0;
+
+ host = pci_find_host_bridge(dev->bus);
+ if (!host)
+ return 0;
- if (dev_cap & PCI_EXP_DEVCAP_EXT_TAG)
+ if (host->broken_ext_tags) {
+ if (ctl & PCI_EXP_DEVCTL_EXT_TAG) {
+ dev_info(&dev->dev, "disabling Extended Tags\n");
+ pcie_capability_clear_word(dev, PCI_EXP_DEVCTL,
+ PCI_EXP_DEVCTL_EXT_TAG);
+ }
+ return 0;
+ }
+ if (!(ctl & PCI_EXP_DEVCTL_EXT_TAG)) {
+ dev_info(&dev->dev, "enabling Extended Tags\n");
pcie_capability_set_word(dev, PCI_EXP_DEVCTL,
PCI_EXP_DEVCTL_EXT_TAG);
+ }
+ return 0;
}
+EXPORT_SYMBOL(pci_configure_extended_tags);
static void pci_configure_device(struct pci_dev *dev)
{
@@ -1707,7 +1732,7 @@ static void pci_configure_device(struct pci_dev *dev)
int ret;
pci_configure_mps(dev);
- pci_configure_extended_tags(dev);
+ pci_configure_extended_tags(dev, NULL);
memset(&hpp, 0, sizeof(hpp));
ret = pci_get_hp_params(dev, &hpp);
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 085fb78..b5dc99c 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4664,3 +4664,22 @@ static void quirk_intel_no_flr(struct pci_dev *dev)
}
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1502, quirk_intel_no_flr);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1503, quirk_intel_no_flr);
+
+static void quirk_exttags_completer(struct pci_dev *pdev)
+{
+ struct pci_host_bridge *bridge = pci_find_host_bridge(pdev->bus);
+
+ if (!bridge)
+ return;
+
+ bridge->broken_ext_tags = 1;
+ dev_info(&pdev->dev, "Extended Tag handling is broken\n");
+
+ pci_walk_bus(bridge->bus, pci_configure_extended_tags, NULL);
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, 0x0140,
+ quirk_exttags_completer);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, 0x0142,
+ quirk_exttags_completer);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, 0x0144,
+ quirk_exttags_completer);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 8039f9f..2b22c3e 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -441,6 +441,7 @@ struct pci_host_bridge {
void *release_data;
struct msi_controller *msi;
unsigned int ignore_reset_delay:1; /* for entire hierarchy */
+ unsigned int broken_ext_tags:1;
/* Resource alignment requirements */
resource_size_t (*align_resource)(struct pci_dev *dev,
const struct resource *res,
--
1.9.1
