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authorBjorn Helgaas <bhelgaas@google.com>2019-05-13 18:34:30 -0500
committerBjorn Helgaas <bhelgaas@google.com>2019-05-13 18:34:30 -0500
commit178901bf6a7d8e6d22fb8265a8886f1ba0272fc7 (patch)
tree99bf1c3a549db7c7044c30afcbefbb5f69ddd44f /drivers/pci
parent156752817cb090643f7e20094d17dbd2c3f14f0d (diff)
parent2dbce590117981196fe355efc0569bc6f949ae9b (diff)
downloadlinux-178901bf6a7d8e6d22fb8265a8886f1ba0272fc7.tar.bz2
Merge branch 'pci/enumeration'
- Enable PCIe services for host controller drivers that use managed host bridge alloc (Jean-Philippe Brucker) - Add quirk to clear PCIe Retrain Link bit to work around Pericom bridge erratum (Stefan Mätje) - Add "external-facing" DT property to identify cases where we require IOMMU protection from untrusted devices (Jean-Philippe Brucker) - Support fixed bus numbers from bridge Enhanced Allocation capabilities (Subbaraya Sundeep) * pci/enumeration: PCI: Assign bus numbers present in EA capability for bridges PCI: OF: Support "external-facing" property dt-bindings: Add "external-facing" PCIe port property PCI: Rework pcie_retrain_link() wait loop PCI: Work around Pericom PCIe-to-PCI bridge Retrain Link erratum PCI: Factor out pcie_retrain_link() function PCI: Init PCIe feature bits for managed host bridge alloc
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/of.c14
-rw-r--r--drivers/pci/pcie/aspm.c47
-rw-r--r--drivers/pci/probe.c77
-rw-r--r--drivers/pci/quirks.c17
4 files changed, 122 insertions, 33 deletions
diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 3d32da15c215..67376cf45880 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -31,10 +31,16 @@ void pci_release_of_node(struct pci_dev *dev)
void pci_set_bus_of_node(struct pci_bus *bus)
{
- if (bus->self == NULL)
- bus->dev.of_node = pcibios_get_phb_of_node(bus);
- else
- bus->dev.of_node = of_node_get(bus->self->dev.of_node);
+ struct device_node *node;
+
+ if (bus->self == NULL) {
+ node = pcibios_get_phb_of_node(bus);
+ } else {
+ node = of_node_get(bus->self->dev.of_node);
+ if (node && of_property_read_bool(node, "external-facing"))
+ bus->self->untrusted = true;
+ }
+ bus->dev.of_node = node;
}
void pci_release_bus_of_node(struct pci_bus *bus)
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 727e3c1ef9a4..fd4cb75088f9 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -196,6 +196,36 @@ static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist)
link->clkpm_capable = (blacklist) ? 0 : capable;
}
+static bool pcie_retrain_link(struct pcie_link_state *link)
+{
+ struct pci_dev *parent = link->pdev;
+ unsigned long end_jiffies;
+ u16 reg16;
+
+ pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &reg16);
+ reg16 |= PCI_EXP_LNKCTL_RL;
+ pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16);
+ if (parent->clear_retrain_link) {
+ /*
+ * Due to an erratum in some devices the Retrain Link bit
+ * needs to be cleared again manually to allow the link
+ * training to succeed.
+ */
+ reg16 &= ~PCI_EXP_LNKCTL_RL;
+ pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16);
+ }
+
+ /* Wait for link training end. Break out after waiting for timeout */
+ end_jiffies = jiffies + LINK_RETRAIN_TIMEOUT;
+ do {
+ pcie_capability_read_word(parent, PCI_EXP_LNKSTA, &reg16);
+ if (!(reg16 & PCI_EXP_LNKSTA_LT))
+ break;
+ msleep(1);
+ } while (time_before(jiffies, end_jiffies));
+ return !(reg16 & PCI_EXP_LNKSTA_LT);
+}
+
/*
* pcie_aspm_configure_common_clock: check if the 2 ends of a link
* could use common clock. If they are, configure them to use the
@@ -205,7 +235,6 @@ static void pcie_aspm_configure_common_clock(struct pcie_link_state *link)
{
int same_clock = 1;
u16 reg16, parent_reg, child_reg[8];
- unsigned long start_jiffies;
struct pci_dev *child, *parent = link->pdev;
struct pci_bus *linkbus = parent->subordinate;
/*
@@ -263,21 +292,7 @@ static void pcie_aspm_configure_common_clock(struct pcie_link_state *link)
reg16 &= ~PCI_EXP_LNKCTL_CCC;
pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16);
- /* Retrain link */
- reg16 |= PCI_EXP_LNKCTL_RL;
- pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16);
-
- /* Wait for link training end. Break out after waiting for timeout */
- start_jiffies = jiffies;
- for (;;) {
- pcie_capability_read_word(parent, PCI_EXP_LNKSTA, &reg16);
- if (!(reg16 & PCI_EXP_LNKSTA_LT))
- break;
- if (time_after(jiffies, start_jiffies + LINK_RETRAIN_TIMEOUT))
- break;
- msleep(1);
- }
- if (!(reg16 & PCI_EXP_LNKSTA_LT))
+ if (pcie_retrain_link(link))
return;
/* Training failed. Restore common clock configurations */
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 2ec0df04e0dc..a6874c306908 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -586,16 +586,9 @@ static void pci_release_host_bridge_dev(struct device *dev)
kfree(to_pci_host_bridge(dev));
}
-struct pci_host_bridge *pci_alloc_host_bridge(size_t priv)
+static void pci_init_host_bridge(struct pci_host_bridge *bridge)
{
- struct pci_host_bridge *bridge;
-
- bridge = kzalloc(sizeof(*bridge) + priv, GFP_KERNEL);
- if (!bridge)
- return NULL;
-
INIT_LIST_HEAD(&bridge->windows);
- bridge->dev.release = pci_release_host_bridge_dev;
/*
* We assume we can manage these PCIe features. Some systems may
@@ -608,6 +601,18 @@ struct pci_host_bridge *pci_alloc_host_bridge(size_t priv)
bridge->native_shpc_hotplug = 1;
bridge->native_pme = 1;
bridge->native_ltr = 1;
+}
+
+struct pci_host_bridge *pci_alloc_host_bridge(size_t priv)
+{
+ struct pci_host_bridge *bridge;
+
+ bridge = kzalloc(sizeof(*bridge) + priv, GFP_KERNEL);
+ if (!bridge)
+ return NULL;
+
+ pci_init_host_bridge(bridge);
+ bridge->dev.release = pci_release_host_bridge_dev;
return bridge;
}
@@ -622,7 +627,7 @@ struct pci_host_bridge *devm_pci_alloc_host_bridge(struct device *dev,
if (!bridge)
return NULL;
- INIT_LIST_HEAD(&bridge->windows);
+ pci_init_host_bridge(bridge);
bridge->dev.release = devm_pci_release_host_bridge_dev;
return bridge;
@@ -1081,6 +1086,36 @@ static void pci_enable_crs(struct pci_dev *pdev)
static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus,
unsigned int available_buses);
+/**
+ * pci_ea_fixed_busnrs() - Read fixed Secondary and Subordinate bus
+ * numbers from EA capability.
+ * @dev: Bridge
+ * @sec: updated with secondary bus number from EA
+ * @sub: updated with subordinate bus number from EA
+ *
+ * If @dev is a bridge with EA capability, update @sec and @sub with
+ * fixed bus numbers from the capability and return true. Otherwise,
+ * return false.
+ */
+static bool pci_ea_fixed_busnrs(struct pci_dev *dev, u8 *sec, u8 *sub)
+{
+ int ea, offset;
+ u32 dw;
+
+ if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE)
+ return false;
+
+ /* find PCI EA capability in list */
+ ea = pci_find_capability(dev, PCI_CAP_ID_EA);
+ if (!ea)
+ return false;
+
+ offset = ea + PCI_EA_FIRST_ENT;
+ pci_read_config_dword(dev, offset, &dw);
+ *sec = dw & PCI_EA_SEC_BUS_MASK;
+ *sub = (dw & PCI_EA_SUB_BUS_MASK) >> PCI_EA_SUB_BUS_SHIFT;
+ return true;
+}
/*
* pci_scan_bridge_extend() - Scan buses behind a bridge
@@ -1115,6 +1150,9 @@ static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev,
u16 bctl;
u8 primary, secondary, subordinate;
int broken = 0;
+ bool fixed_buses;
+ u8 fixed_sec, fixed_sub;
+ int next_busnr;
/*
* Make sure the bridge is powered on to be able to access config
@@ -1214,17 +1252,24 @@ static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev,
/* Clear errors */
pci_write_config_word(dev, PCI_STATUS, 0xffff);
+ /* Read bus numbers from EA Capability (if present) */
+ fixed_buses = pci_ea_fixed_busnrs(dev, &fixed_sec, &fixed_sub);
+ if (fixed_buses)
+ next_busnr = fixed_sec;
+ else
+ next_busnr = max + 1;
+
/*
* Prevent assigning a bus number that already exists.
* This can happen when a bridge is hot-plugged, so in this
* case we only re-scan this bus.
*/
- child = pci_find_bus(pci_domain_nr(bus), max+1);
+ child = pci_find_bus(pci_domain_nr(bus), next_busnr);
if (!child) {
- child = pci_add_new_bus(bus, dev, max+1);
+ child = pci_add_new_bus(bus, dev, next_busnr);
if (!child)
goto out;
- pci_bus_insert_busn_res(child, max+1,
+ pci_bus_insert_busn_res(child, next_busnr,
bus->busn_res.end);
}
max++;
@@ -1285,7 +1330,13 @@ static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev,
max += i;
}
- /* Set subordinate bus number to its real value */
+ /*
+ * Set subordinate bus number to its real value.
+ * If fixed subordinate bus number exists from EA
+ * capability then use it.
+ */
+ if (fixed_buses)
+ max = fixed_sub;
pci_bus_update_busn_res_end(child, max);
pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, max);
}
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index a59ad09ce911..6f34e17c98f4 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -2245,6 +2245,23 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x10f1, quirk_disable_aspm_l0s);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x10f4, quirk_disable_aspm_l0s);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x1508, quirk_disable_aspm_l0s);
+/*
+ * Some Pericom PCIe-to-PCI bridges in reverse mode need the PCIe Retrain
+ * Link bit cleared after starting the link retrain process to allow this
+ * process to finish.
+ *
+ * Affected devices: PI7C9X110, PI7C9X111SL, PI7C9X130. See also the
+ * Pericom Errata Sheet PI7C9X111SLB_errata_rev1.2_102711.pdf.
+ */
+static void quirk_enable_clear_retrain_link(struct pci_dev *dev)
+{
+ dev->clear_retrain_link = 1;
+ pci_info(dev, "Enable PCIe Retrain Link quirk\n");
+}
+DECLARE_PCI_FIXUP_HEADER(0x12d8, 0xe110, quirk_enable_clear_retrain_link);
+DECLARE_PCI_FIXUP_HEADER(0x12d8, 0xe111, quirk_enable_clear_retrain_link);
+DECLARE_PCI_FIXUP_HEADER(0x12d8, 0xe130, quirk_enable_clear_retrain_link);
+
static void fixup_rev1_53c810(struct pci_dev *dev)
{
u32 class = dev->class;