From 4f802170a861265680cad03f47b19c4c3a137052 Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Thu, 20 Sep 2018 10:27:08 -0600 Subject: [PATCH] PCI/DPC: Save and restore config state This patch provides DPC save and restore capabilities. This is necessary for the driver to observe DPC events in the event the configuration space needs to be restored after a reset. Signed-off-by: Keith Busch Signed-off-by: Bjorn Helgaas Reviewed-by: Sinan Kaya --- drivers/pci/pci.c | 2 ++ drivers/pci/pci.h | 8 ++++++ drivers/pci/pcie/dpc.c | 61 +++++++++++++++++++++++++++++++++++++----- 3 files changed, 65 insertions(+), 6 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 0e54588825cb..d6bb56fbee6d 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1284,6 +1284,7 @@ int pci_save_state(struct pci_dev *dev) if (i != 0) return i; + pci_save_dpc_state(dev); return pci_save_vc_state(dev); } EXPORT_SYMBOL(pci_save_state); @@ -1378,6 +1379,7 @@ void pci_restore_state(struct pci_dev *dev) pci_restore_ats_state(dev); pci_restore_vc_state(dev); pci_restore_rebar_state(dev); + pci_restore_dpc_state(dev); pci_cleanup_aer_error_status_regs(dev); diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 6e0d1528d471..b5af5642c6c9 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -346,6 +346,14 @@ int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info); void aer_print_error(struct pci_dev *dev, struct aer_err_info *info); #endif /* CONFIG_PCIEAER */ +#ifdef CONFIG_PCIE_DPC +void pci_save_dpc_state(struct pci_dev *dev); +void pci_restore_dpc_state(struct pci_dev *dev); +#else +static inline void pci_save_dpc_state(struct pci_dev *dev) {} +static inline void pci_restore_dpc_state(struct pci_dev *dev) {} +#endif + #ifdef CONFIG_PCI_ATS void pci_restore_ats_state(struct pci_dev *dev); #else diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c index a1fd16bf1cab..ed815a28512e 100644 --- a/drivers/pci/pcie/dpc.c +++ b/drivers/pci/pcie/dpc.c @@ -44,6 +44,58 @@ static const char * const rp_pio_error_string[] = { "Memory Request Completion Timeout", /* Bit Position 18 */ }; +static struct dpc_dev *to_dpc_dev(struct pci_dev *dev) +{ + struct device *device; + + device = pcie_port_find_device(dev, PCIE_PORT_SERVICE_DPC); + if (!device) + return NULL; + return get_service_data(to_pcie_device(device)); +} + +void pci_save_dpc_state(struct pci_dev *dev) +{ + struct dpc_dev *dpc; + struct pci_cap_saved_state *save_state; + u16 *cap; + + if (!pci_is_pcie(dev)) + return; + + dpc = to_dpc_dev(dev); + if (!dpc) + return; + + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_DPC); + if (!save_state) + return; + + cap = (u16 *)&save_state->cap.data[0]; + pci_read_config_word(dev, dpc->cap_pos + PCI_EXP_DPC_CTL, cap); +} + +void pci_restore_dpc_state(struct pci_dev *dev) +{ + struct dpc_dev *dpc; + struct pci_cap_saved_state *save_state; + u16 *cap; + + if (!pci_is_pcie(dev)) + return; + + dpc = to_dpc_dev(dev); + if (!dpc) + return; + + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_DPC); + if (!save_state) + return; + + cap = (u16 *)&save_state->cap.data[0]; + pci_write_config_word(dev, dpc->cap_pos + PCI_EXP_DPC_CTL, *cap); +} + static int dpc_wait_rp_inactive(struct dpc_dev *dpc) { unsigned long timeout = jiffies + HZ; @@ -67,18 +119,13 @@ static int dpc_wait_rp_inactive(struct dpc_dev *dpc) static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev) { struct dpc_dev *dpc; - struct pcie_device *pciedev; - struct device *devdpc; - u16 cap; /* * DPC disables the Link automatically in hardware, so it has * already been reset by the time we get here. */ - devdpc = pcie_port_find_device(pdev, PCIE_PORT_SERVICE_DPC); - pciedev = to_pcie_device(devdpc); - dpc = get_service_data(pciedev); + dpc = to_dpc_dev(pdev); cap = dpc->cap_pos; /* @@ -259,6 +306,8 @@ static int dpc_probe(struct pcie_device *dev) FLAG(cap, PCI_EXP_DPC_CAP_POISONED_TLP), FLAG(cap, PCI_EXP_DPC_CAP_SW_TRIGGER), dpc->rp_log_size, FLAG(cap, PCI_EXP_DPC_CAP_DL_ACTIVE)); + + pci_add_ext_cap_save_buffer(pdev, PCI_EXT_CAP_ID_DPC, sizeof(u16)); return status; } -- 2.30.2