From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: From: Jon Derrick To: Cc: , , Bjorn Helgaas , Keith Busch , Sinan Kaya , Oza Pawandeep , Dongdong Liu , Jon Derrick Subject: [PATCH 1/2] PCI/DPC: Add 'nodpc' parameter Date: Wed, 15 Aug 2018 15:26:39 -0600 Message-Id: <1534368400-2807-1-git-send-email-jonathan.derrick@intel.com> List-ID: Some users may want to disable downstream port containment (DPC), so give them this option Signed-off-by: Jon Derrick --- drivers/pci/pci.c | 2 ++ drivers/pci/pci.h | 6 ++++++ drivers/pci/pcie/dpc.c | 48 ++++++++++++++++++++++++++++++++++++++---------- include/linux/pci.h | 6 ++++++ 4 files changed, 52 insertions(+), 10 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 80da484..4e629c2 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -6062,6 +6062,8 @@ static int __init pci_setup(char *str) pcie_ats_disabled = true; } else if (!strcmp(str, "noaer")) { pci_no_aer(); + } else if (!strcmp(str, "nodpc")) { + pci_no_dpc(); } else if (!strcmp(str, "earlydump")) { pci_early_dump = true; } else if (!strncmp(str, "realloc=", 8)) { diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 6e0d152..f73f29e 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -536,4 +536,10 @@ static inline void pci_aer_clear_fatal_status(struct pci_dev *dev) { } static inline void pci_aer_clear_device_status(struct pci_dev *dev) { } #endif +#ifdef CONFIG_PCIE_DPC +void pci_no_dpc(void); +#else +static inline void pci_no_dpc(void) { } +#endif + #endif /* DRIVERS_PCI_H */ diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c index f03279f..068fca0 100644 --- a/drivers/pci/pcie/dpc.c +++ b/drivers/pci/pcie/dpc.c @@ -44,6 +44,18 @@ struct dpc_dev { "Memory Request Completion Timeout", /* Bit Position 18 */ }; +static int pcie_dpc_disable; + +void pci_no_dpc(void) +{ + pcie_dpc_disable = 1; +} + +bool pci_dpc_available(void) +{ + return !pcie_dpc_disable && pci_aer_available() && pci_msi_enabled(); +} + static int dpc_wait_rp_inactive(struct dpc_dev *dpc) { unsigned long timeout = jiffies + HZ; @@ -209,6 +221,17 @@ static irqreturn_t dpc_irq(int irq, void *context) return IRQ_HANDLED; } +static void dpc_disable(struct pci_dev *pdev) +{ + u16 cap_pos, ctl; + + cap_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DPC); + pci_read_config_word(pdev, cap_pos + PCI_EXP_DPC_CTL, &ctl); + ctl &= ~(PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_EN_NONFATAL | + PCI_EXP_DPC_CTL_INT_EN); + pci_write_config_word(pdev, cap_pos + PCI_EXP_DPC_CTL, ctl); +} + #define FLAG(x, y) (((x) & (y)) ? '+' : '-') static int dpc_probe(struct pcie_device *dev) { @@ -221,9 +244,16 @@ static int dpc_probe(struct pcie_device *dev) if (pcie_aer_get_firmware_first(pdev)) return -ENOTSUPP; + if (!pci_dpc_available()) { + status = -ENOTSUPP; + goto disable_dpc; + } + dpc = devm_kzalloc(device, sizeof(*dpc), GFP_KERNEL); - if (!dpc) - return -ENOMEM; + if (!dpc) { + status = -ENOMEM; + goto disable_dpc; + } dpc->cap_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DPC); dpc->dev = dev; @@ -235,7 +265,7 @@ static int dpc_probe(struct pcie_device *dev) if (status) { dev_warn(device, "request IRQ%d failed: %d\n", dev->irq, status); - return status; + goto disable_dpc; } pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CAP, &cap); @@ -260,17 +290,15 @@ static int dpc_probe(struct pcie_device *dev) FLAG(cap, PCI_EXP_DPC_CAP_SW_TRIGGER), dpc->rp_log_size, FLAG(cap, PCI_EXP_DPC_CAP_DL_ACTIVE)); return status; + +disable_dpc: + dpc_disable(pdev); + return status; } static void dpc_remove(struct pcie_device *dev) { - struct dpc_dev *dpc = get_service_data(dev); - struct pci_dev *pdev = dev->port; - u16 ctl; - - pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, &ctl); - ctl &= ~(PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_INT_EN); - pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, ctl); + dpc_disable(dev->port); } static struct pcie_port_service_driver dpcdriver = { diff --git a/include/linux/pci.h b/include/linux/pci.h index 5454e6b..559b792 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1473,6 +1473,12 @@ static inline int pci_irqd_intx_xlate(struct irq_domain *d, static inline bool pci_aer_available(void) { return false; } #endif +#ifdef CONFIG_PCIE_DPC +bool pci_dpc_available(void); +#else +static inline bool pci_dpc_available(void) { return false; } +#endif + #ifdef CONFIG_PCIE_ECRC void pcie_set_ecrc_checking(struct pci_dev *dev); void pcie_ecrc_get_policy(char *str); -- 1.8.3.1