From 76002d8b48c4b08c9bd414517dd295e132ad910b Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Wed, 1 May 2019 11:00:16 -0600 Subject: [PATCH 1/4] PCI: Return error if cannot probe VF Commit 0e7df22401a3 ("PCI: Add sysfs sriov_drivers_autoprobe to control VF driver binding") allows the user to specify that drivers for VFs of a PF should not be probed, but it actually causes pci_device_probe() to return success back to the driver core in this case. Therefore by all sysfs appearances the device is bound to a driver, the driver link from the device exists as does the device link back from the driver, yet the driver's probe function is never called on the device. We also fail to do any sort of cleanup when we're prohibited from probing the device, the IRQ setup remains in place and we even hold a device reference. Instead, abort with errno before any setup or references are taken when pci_device_can_probe() prevents us from trying to probe the device. Link: https://lore.kernel.org/lkml/155672991496.20698.4279330795743262888.stgit@gimli.home Fixes: 0e7df22401a3 ("PCI: Add sysfs sriov_drivers_autoprobe to control VF driver binding") Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas --- drivers/pci/pci-driver.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index cae630fe6387..53874aae3873 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -414,6 +414,9 @@ static int pci_device_probe(struct device *dev) struct pci_dev *pci_dev = to_pci_dev(dev); struct pci_driver *drv = to_pci_driver(dev->driver); + if (!pci_device_can_probe(pci_dev)) + return -ENODEV; + pci_assign_irq(pci_dev); error = pcibios_alloc_irq(pci_dev); @@ -421,12 +424,10 @@ static int pci_device_probe(struct device *dev) return error; pci_dev_get(pci_dev); - if (pci_device_can_probe(pci_dev)) { - error = __pci_device_probe(drv, pci_dev); - if (error) { - pcibios_free_irq(pci_dev); - pci_dev_put(pci_dev); - } + error = __pci_device_probe(drv, pci_dev); + if (error) { + pcibios_free_irq(pci_dev); + pci_dev_put(pci_dev); } return error; From 2d2f4273cbe9058d1f5a518e5e880d27d7b3b30f Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Thu, 9 May 2019 13:27:22 -0600 Subject: [PATCH 2/4] PCI: Always allow probing with driver_override Commit 0e7df22401a3 ("PCI: Add sysfs sriov_drivers_autoprobe to control VF driver binding") introduced the sriov_drivers_autoprobe attribute which allows users to prevent the kernel from automatically probing a driver for new VFs as they are created. This allows VFs to be spawned without automatically binding the new device to a host driver, such as in cases where the user intends to use the device only with a meta driver like vfio-pci. However, the current implementation prevents any use of drivers_probe with the VF while sriov_drivers_autoprobe=0. This blocks the now current general practice of setting driver_override followed by using drivers_probe to bind a device to a specified driver. The kernel never automatically sets a driver_override therefore it seems we can assume a driver_override reflects the intent of the user. Also, probing a device using a driver_override match seems outside the scope of the 'auto' part of sriov_drivers_autoprobe. Therefore, let's allow driver_override matches regardless of sriov_drivers_autoprobe, which we can do by simply testing if a driver_override is set for a device as a 'can probe' condition. Fixes: 0e7df22401a3 ("PCI: Add sysfs sriov_drivers_autoprobe to control VF driver binding") Link: https://lore.kernel.org/lkml/155742996741.21878.569845487290798703.stgit@gimli.home Link: https://lore.kernel.org/linux-pci/155672991496.20698.4279330795743262888.stgit@gimli.home/T/#u Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas --- drivers/pci/pci-driver.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 53874aae3873..b6a3a51801f0 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -399,7 +399,8 @@ void __weak pcibios_free_irq(struct pci_dev *dev) #ifdef CONFIG_PCI_IOV static inline bool pci_device_can_probe(struct pci_dev *pdev) { - return (!pdev->is_virtfn || pdev->physfn->sriov->drivers_autoprobe); + return (!pdev->is_virtfn || pdev->physfn->sriov->drivers_autoprobe || + pdev->driver_override); } #else static inline bool pci_device_can_probe(struct pci_dev *pdev) From de76cda215d56256ffcda7ffa538b70f9fb301a7 Mon Sep 17 00:00:00 2001 From: Gustavo Pimentel Date: Tue, 4 Jun 2019 18:24:43 +0200 Subject: [PATCH 3/4] PCI: Decode PCIe 32 GT/s link speed PCIe r5.0, sec 7.5.3.18, defines a new 32.0 GT/s bit in the Supported Link Speeds Vector of Link Capabilities 2. Decode this new speed. This does not affect the speed of the link, which should be negotiated automatically by the hardware; it only adds decoding when showing the speed to the user. Previously, reading the speed of a link operating at this speed showed "Unknown speed" instead of "32.0 GT/s". Link: https://lore.kernel.org/lkml/92365e3caf0fc559f9ab14bcd053bfc92d4f661c.1559664969.git.gustavo.pimentel@synopsys.com Signed-off-by: Gustavo Pimentel [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas --- drivers/pci/pci-sysfs.c | 3 +++ drivers/pci/pci.c | 4 +++- drivers/pci/probe.c | 2 +- drivers/pci/slot.c | 1 + include/linux/pci.h | 1 + include/uapi/linux/pci_regs.h | 4 ++++ 6 files changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 6d27475e39b2..d52d30448e41 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -182,6 +182,9 @@ static ssize_t current_link_speed_show(struct device *dev, return -EINVAL; switch (linkstat & PCI_EXP_LNKSTA_CLS) { + case PCI_EXP_LNKSTA_CLS_32_0GB: + speed = "32 GT/s"; + break; case PCI_EXP_LNKSTA_CLS_16_0GB: speed = "16 GT/s"; break; diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 8abc843b1615..4729a7c7a9d9 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5621,7 +5621,9 @@ enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev) */ pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2, &lnkcap2); if (lnkcap2) { /* PCIe r3.0-compliant */ - if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_16_0GB) + if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_32_0GB) + return PCIE_SPEED_32_0GT; + else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_16_0GB) return PCIE_SPEED_16_0GT; else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_8_0GB) return PCIE_SPEED_8_0GT; diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 0e8e2c186f50..c5f27c8cd140 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -668,7 +668,7 @@ const unsigned char pcie_link_speed[] = { PCIE_SPEED_5_0GT, /* 2 */ PCIE_SPEED_8_0GT, /* 3 */ PCIE_SPEED_16_0GT, /* 4 */ - PCI_SPEED_UNKNOWN, /* 5 */ + PCIE_SPEED_32_0GT, /* 5 */ PCI_SPEED_UNKNOWN, /* 6 */ PCI_SPEED_UNKNOWN, /* 7 */ PCI_SPEED_UNKNOWN, /* 8 */ diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c index f4d92b1afe7b..ae4aa0e1f2f4 100644 --- a/drivers/pci/slot.c +++ b/drivers/pci/slot.c @@ -75,6 +75,7 @@ static const char *pci_bus_speed_strings[] = { "5.0 GT/s PCIe", /* 0x15 */ "8.0 GT/s PCIe", /* 0x16 */ "16.0 GT/s PCIe", /* 0x17 */ + "32.0 GT/s PCIe", /* 0x18 */ }; static ssize_t bus_speed_read(enum pci_bus_speed speed, char *buf) diff --git a/include/linux/pci.h b/include/linux/pci.h index 4a5a84d7bdd4..2173e6b75579 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -258,6 +258,7 @@ enum pci_bus_speed { PCIE_SPEED_5_0GT = 0x15, PCIE_SPEED_8_0GT = 0x16, PCIE_SPEED_16_0GT = 0x17, + PCIE_SPEED_32_0GT = 0x18, PCI_SPEED_UNKNOWN = 0xff, }; diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index 27164769d184..f28e562d7ca8 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -528,6 +528,7 @@ #define PCI_EXP_LNKCAP_SLS_5_0GB 0x00000002 /* LNKCAP2 SLS Vector bit 1 */ #define PCI_EXP_LNKCAP_SLS_8_0GB 0x00000003 /* LNKCAP2 SLS Vector bit 2 */ #define PCI_EXP_LNKCAP_SLS_16_0GB 0x00000004 /* LNKCAP2 SLS Vector bit 3 */ +#define PCI_EXP_LNKCAP_SLS_32_0GB 0x00000005 /* LNKCAP2 SLS Vector bit 4 */ #define PCI_EXP_LNKCAP_MLW 0x000003f0 /* Maximum Link Width */ #define PCI_EXP_LNKCAP_ASPMS 0x00000c00 /* ASPM Support */ #define PCI_EXP_LNKCAP_L0SEL 0x00007000 /* L0s Exit Latency */ @@ -556,6 +557,7 @@ #define PCI_EXP_LNKSTA_CLS_5_0GB 0x0002 /* Current Link Speed 5.0GT/s */ #define PCI_EXP_LNKSTA_CLS_8_0GB 0x0003 /* Current Link Speed 8.0GT/s */ #define PCI_EXP_LNKSTA_CLS_16_0GB 0x0004 /* Current Link Speed 16.0GT/s */ +#define PCI_EXP_LNKSTA_CLS_32_0GB 0x0005 /* Current Link Speed 32.0GT/s */ #define PCI_EXP_LNKSTA_NLW 0x03f0 /* Negotiated Link Width */ #define PCI_EXP_LNKSTA_NLW_X1 0x0010 /* Current Link Width x1 */ #define PCI_EXP_LNKSTA_NLW_X2 0x0020 /* Current Link Width x2 */ @@ -661,6 +663,7 @@ #define PCI_EXP_LNKCAP2_SLS_5_0GB 0x00000004 /* Supported Speed 5GT/s */ #define PCI_EXP_LNKCAP2_SLS_8_0GB 0x00000008 /* Supported Speed 8GT/s */ #define PCI_EXP_LNKCAP2_SLS_16_0GB 0x00000010 /* Supported Speed 16GT/s */ +#define PCI_EXP_LNKCAP2_SLS_32_0GB 0x00000020 /* Supported Speed 32GT/s */ #define PCI_EXP_LNKCAP2_CROSSLINK 0x00000100 /* Crosslink supported */ #define PCI_EXP_LNKCTL2 48 /* Link Control 2 */ #define PCI_EXP_LNKCTL2_TLS 0x000f @@ -668,6 +671,7 @@ #define PCI_EXP_LNKCTL2_TLS_5_0GT 0x0002 /* Supported Speed 5GT/s */ #define PCI_EXP_LNKCTL2_TLS_8_0GT 0x0003 /* Supported Speed 8GT/s */ #define PCI_EXP_LNKCTL2_TLS_16_0GT 0x0004 /* Supported Speed 16GT/s */ +#define PCI_EXP_LNKCTL2_TLS_32_0GT 0x0005 /* Supported Speed 32GT/s */ #define PCI_EXP_LNKSTA2 50 /* Link Status 2 */ #define PCI_CAP_EXP_ENDPOINT_SIZEOF_V2 52 /* v2 endpoints with link end here */ #define PCI_EXP_SLTCAP2 52 /* Slot Capabilities 2 */ From dc6b698a86fe40a50525433eb8e92a267847f6f9 Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Mon, 27 May 2019 00:51:51 +0200 Subject: [PATCH 4/4] PCI: sysfs: Ignore lockdep for remove attribute With CONFIG_PROVE_LOCKING=y, using sysfs to remove a bridge with a device below it causes a lockdep warning, e.g., # echo 1 > /sys/class/pci_bus/0000:00/device/0000:00:00.0/remove ============================================ WARNING: possible recursive locking detected ... pci_bus 0000:01: busn_res: [bus 01] is released The remove recursively removes the subtree below the bridge. Each call uses a different lock so there's no deadlock, but the locks were all created with the same lockdep key so the lockdep checker can't tell them apart. Mark the "remove" sysfs attribute with __ATTR_IGNORE_LOCKDEP() as it is safe to ignore the lockdep check between different "remove" kernfs instances. There's discussion about a similar issue in USB at [1], which resulted in 356c05d58af0 ("sysfs: get rid of some lockdep false positives") and e9b526fe7048 ("i2c: suppress lockdep warning on delete_device"), which do basically the same thing for USB "remove" and i2c "delete_device" files. [1] https://lore.kernel.org/r/Pine.LNX.4.44L0.1204251436140.1206-100000@iolanthe.rowland.org Link: https://lore.kernel.org/r/20190526225151.3865-1-marek.vasut@gmail.com Signed-off-by: Marek Vasut [bhelgaas: trim commit log, details at above links] Signed-off-by: Bjorn Helgaas Cc: Geert Uytterhoeven Cc: Phil Edworthy Cc: Simon Horman Cc: Tejun Heo Cc: Wolfram Sang --- drivers/pci/pci-sysfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index d52d30448e41..965c72104150 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -480,7 +480,7 @@ static ssize_t remove_store(struct device *dev, struct device_attribute *attr, pci_stop_and_remove_bus_device_locked(to_pci_dev(dev)); return count; } -static struct device_attribute dev_remove_attr = __ATTR(remove, +static struct device_attribute dev_remove_attr = __ATTR_IGNORE_LOCKDEP(remove, (S_IWUSR|S_IWGRP), NULL, remove_store);