From 6302bf3ef78dd210b5ff4a922afcb7d8eff8a211 Mon Sep 17 00:00:00 2001 From: Jean-Philippe Brucker Date: Mon, 18 Mar 2019 16:07:18 +0000 Subject: PCI: Init PCIe feature bits for managed host bridge alloc Two functions allocate a host bridge: devm_pci_alloc_host_bridge() and pci_alloc_host_bridge(). At the moment, only the unmanaged one initializes the PCIe feature bits, which prevents from using features such as hotplug or AER on some systems, when booting with device tree. Make the initialization code common. Fixes: 02bfeb484230 ("PCI/portdrv: Simplify PCIe feature permission checking") Signed-off-by: Jean-Philippe Brucker Signed-off-by: Bjorn Helgaas CC: stable@vger.kernel.org # v4.17+ --- drivers/pci/probe.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 2ec0df04e0dc..012250a78da7 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; -- cgit From 86fa6a344209d9414ea962b1f1ac6ade9dd7563a Mon Sep 17 00:00:00 2001 From: Stefan Mätje Date: Fri, 29 Mar 2019 18:07:34 +0100 Subject: PCI: Factor out pcie_retrain_link() function MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Factor out pcie_retrain_link() to use for Pericom Retrain Link quirk. No functional change intended. Signed-off-by: Stefan Mätje Signed-off-by: Bjorn Helgaas Reviewed-by: Andy Shevchenko CC: stable@vger.kernel.org --- drivers/pci/pcie/aspm.c | 40 ++++++++++++++++++++++++---------------- 1 file changed, 24 insertions(+), 16 deletions(-) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 727e3c1ef9a4..4fa37622ad66 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -196,6 +196,29 @@ 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 start_jiffies; + u16 reg16; + + pcie_capability_read_word(parent, PCI_EXP_LNKCTL, ®16); + 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, ®16); + if (!(reg16 & PCI_EXP_LNKSTA_LT)) + break; + if (time_after(jiffies, start_jiffies + LINK_RETRAIN_TIMEOUT)) + break; + msleep(1); + } + 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 +228,6 @@ 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 +285,7 @@ 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, ®16); - 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 */ -- cgit From 4ec73791a64bab25cabf16a6067ee478692e506d Mon Sep 17 00:00:00 2001 From: Stefan Mätje Date: Fri, 29 Mar 2019 18:07:35 +0100 Subject: PCI: Work around Pericom PCIe-to-PCI bridge Retrain Link erratum MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Due to an erratum in some Pericom PCIe-to-PCI bridges in reverse mode (conventional PCI on primary side, PCIe on downstream side), the Retrain Link bit needs to be cleared manually to allow the link training to complete successfully. If it is not cleared manually, the link training is continuously restarted and no devices below the PCI-to-PCIe bridge can be accessed. That means drivers for devices below the bridge will be loaded but won't work and may even crash because the driver is only reading 0xffff. See the Pericom Errata Sheet PI7C9X111SLB_errata_rev1.2_102711.pdf for details. Devices known as affected so far are: PI7C9X110, PI7C9X111SL, PI7C9X130. Add a new flag, clear_retrain_link, in struct pci_dev. Quirks for affected devices set this bit. Note that pcie_retrain_link() lives in aspm.c because that's currently the only place we use it, but this erratum is not specific to ASPM, and we may retrain links for other reasons in the future. Signed-off-by: Stefan Mätje [bhelgaas: apply regardless of CONFIG_PCIEASPM] Signed-off-by: Bjorn Helgaas Reviewed-by: Andy Shevchenko CC: stable@vger.kernel.org --- drivers/pci/pcie/aspm.c | 9 +++++++++ drivers/pci/quirks.c | 17 +++++++++++++++++ include/linux/pci.h | 2 ++ 3 files changed, 28 insertions(+) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 4fa37622ad66..38e7017478b5 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -205,6 +205,15 @@ static bool pcie_retrain_link(struct pcie_link_state *link) pcie_capability_read_word(parent, PCI_EXP_LNKCTL, ®16); 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 */ start_jiffies = jiffies; 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; diff --git a/include/linux/pci.h b/include/linux/pci.h index 77448215ef5b..2c056a7a728a 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -348,6 +348,8 @@ struct pci_dev { unsigned int hotplug_user_indicators:1; /* SlotCtl indicators controlled exclusively by user sysfs */ + unsigned int clear_retrain_link:1; /* Need to clear Retrain Link + bit manually */ unsigned int d3_delay; /* D3->D0 transition time in ms */ unsigned int d3cold_delay; /* D3cold->D0 transition time in ms */ -- cgit From 658eec837b11fbfab9082ebf8da24d94cefa47c0 Mon Sep 17 00:00:00 2001 From: Stefan Mätje Date: Fri, 29 Mar 2019 18:07:36 +0100 Subject: PCI: Rework pcie_retrain_link() wait loop MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Transform wait code to a "do {} while (time_before())" loop as recommended by reviewer. No functional change intended. Signed-off-by: Stefan Mätje Signed-off-by: Bjorn Helgaas Reviewed-by: Andy Shevchenko --- drivers/pci/pcie/aspm.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 38e7017478b5..fd4cb75088f9 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -199,7 +199,7 @@ static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist) static bool pcie_retrain_link(struct pcie_link_state *link) { struct pci_dev *parent = link->pdev; - unsigned long start_jiffies; + unsigned long end_jiffies; u16 reg16; pcie_capability_read_word(parent, PCI_EXP_LNKCTL, ®16); @@ -216,15 +216,13 @@ static bool pcie_retrain_link(struct pcie_link_state *link) } /* Wait for link training end. Break out after waiting for timeout */ - start_jiffies = jiffies; - for (;;) { + end_jiffies = jiffies + LINK_RETRAIN_TIMEOUT; + do { pcie_capability_read_word(parent, PCI_EXP_LNKSTA, ®16); if (!(reg16 & PCI_EXP_LNKSTA_LT)) break; - if (time_after(jiffies, start_jiffies + LINK_RETRAIN_TIMEOUT)) - break; msleep(1); - } + } while (time_before(jiffies, end_jiffies)); return !(reg16 & PCI_EXP_LNKSTA_LT); } -- cgit From badd9f19f1992218b771c72e0cdc8825dd45938c Mon Sep 17 00:00:00 2001 From: Jean-Philippe Brucker Date: Thu, 11 Apr 2019 13:40:26 +0100 Subject: dt-bindings: Add "external-facing" PCIe port property Provide a way for the firmware to tell the OS which devices are external to the machine and therefore untrusted. The property can describe for example Thunderbolt and other user-accessible ports, which should always have the strongest IOMMU protection. Signed-off-by: Jean-Philippe Brucker Signed-off-by: Bjorn Helgaas Reviewed-by: Grant Likely Reviewed-by: Rob Herring Reviewed-by: Robin Murphy --- Documentation/devicetree/bindings/pci/pci.txt | 50 +++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/Documentation/devicetree/bindings/pci/pci.txt b/Documentation/devicetree/bindings/pci/pci.txt index c77981c5dd18..92c01db610df 100644 --- a/Documentation/devicetree/bindings/pci/pci.txt +++ b/Documentation/devicetree/bindings/pci/pci.txt @@ -24,3 +24,53 @@ driver implementation may support the following properties: unsupported link speed, for instance, trying to do training for unsupported link speed, etc. Must be '4' for gen4, '3' for gen3, '2' for gen2, and '1' for gen1. Any other values are invalid. + +PCI-PCI Bridge properties +------------------------- + +PCIe root ports and switch ports may be described explicitly in the device +tree, as children of the host bridge node. Even though those devices are +discoverable by probing, it might be necessary to describe properties that +aren't provided by standard PCIe capabilities. + +Required properties: + +- reg: + Identifies the PCI-PCI bridge. As defined in the IEEE Std 1275-1994 + document, it is a five-cell address encoded as (phys.hi phys.mid + phys.lo size.hi size.lo). phys.hi should contain the device's BDF as + 0b00000000 bbbbbbbb dddddfff 00000000. The other cells should be zero. + + The bus number is defined by firmware, through the standard bridge + configuration mechanism. If this port is a switch port, then firmware + allocates the bus number and writes it into the Secondary Bus Number + register of the bridge directly above this port. Otherwise, the bus + number of a root port is the first number in the bus-range property, + defaulting to zero. + + If firmware leaves the ARI Forwarding Enable bit set in the bridge + above this port, then phys.hi contains the 8-bit function number as + 0b00000000 bbbbbbbb ffffffff 00000000. Note that the PCIe specification + recommends that firmware only leaves ARI enabled when it knows that the + OS is ARI-aware. + +Optional properties: + +- external-facing: + When present, the port is external-facing. All bridges and endpoints + downstream of this port are external to the machine. The OS can, for + example, use this information to identify devices that cannot be + trusted with relaxed DMA protection, as users could easily attach + malicious devices to this port. + +Example: + +pcie@10000000 { + compatible = "pci-host-ecam-generic"; + ... + pcie@0008 { + /* Root port 00:01.0 is external-facing */ + reg = <0x00000800 0 0 0 0>; + external-facing; + }; +}; -- cgit From 9cb30a71acd45d65321c73160626f15fcdceba7a Mon Sep 17 00:00:00 2001 From: Jean-Philippe Brucker Date: Thu, 11 Apr 2019 13:40:27 +0100 Subject: PCI: OF: Support "external-facing" property Set the "untrusted" attribute to any PCIe port that has an "external-facing" device tree property. Any device downstream of this port will inherit the attribute and have only the strictest IOMMU protection. Signed-off-by: Jean-Philippe Brucker Signed-off-by: Bjorn Helgaas --- drivers/pci/of.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 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) -- cgit From 2dbce590117981196fe355efc0569bc6f949ae9b Mon Sep 17 00:00:00 2001 From: Subbaraya Sundeep Date: Mon, 19 Nov 2018 18:44:32 +0530 Subject: PCI: Assign bus numbers present in EA capability for bridges The "Enhanced Allocation (EA) for Memory and I/O Resources" ECN, approved 23 October 2014, sec 6.9.1.2, specifies a second DW in the capability for type 1 (bridge) functions to describe fixed secondary and subordinate bus numbers. This ECN was included in the PCIe r4.0 spec, but sec 6.9.1.2 was omitted, presumably by mistake. Read fixed bus numbers from the EA capability for bridges. Signed-off-by: Subbaraya Sundeep [bhelgaas: add pci_ea_fixed_busnrs() return value] Signed-off-by: Bjorn Helgaas --- drivers/pci/probe.c | 54 +++++++++++++++++++++++++++++++++++++++---- include/uapi/linux/pci_regs.h | 6 +++++ 2 files changed, 56 insertions(+), 4 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 012250a78da7..a6874c306908 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1086,6 +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 @@ -1120,6 +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 @@ -1219,17 +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++; @@ -1290,7 +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/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index 5c98133f2c94..c51e0066de8b 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -372,6 +372,12 @@ #define PCI_EA_FIRST_ENT_BRIDGE 8 /* First EA Entry for Bridges */ #define PCI_EA_ES 0x00000007 /* Entry Size */ #define PCI_EA_BEI 0x000000f0 /* BAR Equivalent Indicator */ + +/* EA fixed Secondary and Subordinate bus numbers for Bridge */ +#define PCI_EA_SEC_BUS_MASK 0xff +#define PCI_EA_SUB_BUS_MASK 0xff00 +#define PCI_EA_SUB_BUS_SHIFT 8 + /* 0-5 map to BARs 0-5 respectively */ #define PCI_EA_BEI_BAR0 0 #define PCI_EA_BEI_BAR5 5 -- cgit