From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> As per PCI firmware specification v3.2 ECN (https://members.pcisig.com/wg/PCI-SIG/document/12614), when firmware owns Downstream Port Containment (DPC), its expected to use the "Error Disconnect Recover" (EDR) notification to alert OSPM of a DPC event and if OS supports EDR, its expected to handle the software state invalidation and port recovery in OS and let firmware know the recovery status via _OST ACPI call. Since EDR is a hybrid service, DPC service shall be enabled in OS even if AER is not natively enabled in OS. Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> --- drivers/pci/pcie/Kconfig | 10 + drivers/pci/pcie/dpc.c | 326 ++++++++++++++++++++++++++++++-- drivers/pci/pcie/portdrv_core.c | 9 +- 3 files changed, 329 insertions(+), 16 deletions(-) diff --git a/drivers/pci/pcie/Kconfig b/drivers/pci/pcie/Kconfig index 5cbdbca904ac..55f65d1cbc9e 100644 --- a/drivers/pci/pcie/Kconfig +++ b/drivers/pci/pcie/Kconfig @@ -142,3 +142,13 @@ config PCIE_PTM This is only useful if you have devices that support PTM, but it is safe to enable even if you don't. + +config PCIE_EDR + bool "PCI Express Error Disconnect Recover support" + default n + depends on PCIE_DPC && ACPI + help + This options adds Error Disconnect Recover support as specified + in PCI firmware specification v3.2 Downstream Port Containment + Related Enhancements ECN. Enable this if you want to support hybrid + DPC model which uses both firmware and OS to implement DPC. diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c index 7b77754a82de..bdf4ca8a0acb 100644 --- a/drivers/pci/pcie/dpc.c +++ b/drivers/pci/pcie/dpc.c @@ -11,6 +11,7 @@ #include <linux/interrupt.h> #include <linux/init.h> #include <linux/pci.h> +#include <linux/acpi.h> #include "portdrv.h" #include "../pci.h" @@ -20,8 +21,23 @@ struct dpc_dev { u16 cap_pos; bool rp_extensions; u8 rp_log_size; + bool native_dpc; + pci_ers_result_t error_state; +#ifdef CONFIG_ACPI + struct acpi_device *adev; +#endif }; +#ifdef CONFIG_ACPI + +#define EDR_PORT_ENABLE_DSM 0x0C +#define EDR_PORT_LOCATE_DSM 0x0D + +static const guid_t pci_acpi_dsm_guid = + GUID_INIT(0xe5c937d0, 0x3553, 0x4d7a, + 0x91, 0x17, 0xea, 0x4d, 0x19, 0xc3, 0x43, 0x4d); +#endif + static const char * const rp_pio_error_string[] = { "Configuration Request received UR Completion", /* Bit Position 0 */ "Configuration Request received CA Completion", /* Bit Position 1 */ @@ -67,6 +83,9 @@ void pci_save_dpc_state(struct pci_dev *dev) if (!dpc) return; + if (!dpc->native_dpc) + return; + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_DPC); if (!save_state) return; @@ -88,6 +107,9 @@ void pci_restore_dpc_state(struct pci_dev *dev) if (!dpc) return; + if (!dpc->native_dpc) + return; + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_DPC); if (!save_state) return; @@ -224,10 +246,9 @@ static int dpc_get_aer_uncorrect_severity(struct pci_dev *dev, return 1; } -static irqreturn_t dpc_handler(int irq, void *context) +static void dpc_process_error(struct dpc_dev *dpc) { struct aer_err_info info; - struct dpc_dev *dpc = context; struct pci_dev *pdev = dpc->dev->port; struct device *dev = &dpc->dev->device; u16 cap = dpc->cap_pos, status, source, reason, ext_reason; @@ -261,6 +282,13 @@ static irqreturn_t dpc_handler(int irq, void *context) /* We configure DPC so it only triggers on ERR_FATAL */ pcie_do_recovery(pdev, pci_channel_io_frozen, PCIE_PORT_SERVICE_DPC); +} + +static irqreturn_t dpc_handler(int irq, void *context) +{ + struct dpc_dev *dpc = context; + + dpc_process_error(dpc); return IRQ_HANDLED; } @@ -283,6 +311,230 @@ static irqreturn_t dpc_irq(int irq, void *context) return IRQ_HANDLED; } +void dpc_error_resume(struct pci_dev *dev) +{ + struct dpc_dev *dpc; + + dpc = to_dpc_dev(dev); + if (!dpc) + return; + + dpc->error_state = PCI_ERS_RESULT_RECOVERED; +} + +#ifdef CONFIG_ACPI + +/* + * _DSM wrapper function to enable/disable DPC port. + * @dpc : DPC device structure + * @enable: status of DPC port (0 or 1). + * + * returns 0 on success or errno on failure. + */ +static int acpi_enable_dpc_port(struct dpc_dev *dpc, bool enable) +{ + union acpi_object *obj; + int status; + union acpi_object argv4; + + /* Check whether EDR_PORT_ENABLE_DSM is supported in firmware */ + status = acpi_check_dsm(dpc->adev->handle, &pci_acpi_dsm_guid, 1, + 1 << EDR_PORT_ENABLE_DSM); + if (!status) + return -ENOTSUPP; + + argv4.type = ACPI_TYPE_INTEGER; + argv4.integer.value = enable; + + obj = acpi_evaluate_dsm(dpc->adev->handle, &pci_acpi_dsm_guid, 1, + EDR_PORT_ENABLE_DSM, &argv4); + if (!obj) + return -EIO; + + if (obj->type == ACPI_TYPE_INTEGER && obj->integer.value == enable) + status = 0; + else + status = -EIO; + + ACPI_FREE(obj); + + return status; +} + +/* + * _DSM wrapper function to locate DPC port. + * @dpc : DPC device structure + * + * returns pci_dev or NULL. + */ +static struct pci_dev *acpi_locate_dpc_port(struct dpc_dev *dpc) +{ + union acpi_object *obj; + int status; + u16 port; + + /* Check whether EDR_PORT_LOCATE_DSM is supported in firmware */ + status = acpi_check_dsm(dpc->adev->handle, &pci_acpi_dsm_guid, 1, + 1 << EDR_PORT_LOCATE_DSM); + if (!status) + return dpc->dev->port; + + + obj = acpi_evaluate_dsm(dpc->adev->handle, &pci_acpi_dsm_guid, 1, + EDR_PORT_LOCATE_DSM, NULL); + if (!obj) + return NULL; + + if (obj->type == ACPI_TYPE_INTEGER) { + /* + * Firmware returns DPC port BDF details in following format: + * 15:8 = bus + * 7:3 = device + * 2:0 = function + */ + port = obj->integer.value; + ACPI_FREE(obj); + } else { + ACPI_FREE(obj); + return NULL; + } + + return pci_get_domain_bus_and_slot(0, PCI_BUS_NUM(port), port & 0xff); +} + +/* + * _OST wrapper function to let firmware know the status of EDR event. + * @dpc : DPC device structure. + * @status: Status of EDR event. + * + */ +static int acpi_send_edr_status(struct dpc_dev *dpc, u16 status) +{ + u32 ost_status; + struct pci_dev *pdev = dpc->dev->port; + + dev_dbg(&pdev->dev, "Sending EDR status :%x\n", status); + + ost_status = PCI_DEVID(pdev->bus->number, pdev->devfn); + ost_status = (ost_status << 16) | status; + + if (!acpi_has_method(dpc->adev->handle, "_OST")) + return -ENOTSUPP; + + status = acpi_evaluate_ost(dpc->adev->handle, + ACPI_NOTIFY_DISCONNECT_RECOVER, + ost_status, NULL); + if (ACPI_FAILURE(status)) + return -EINVAL; + + return 0; +} + +/* + * Helper function used for disconnecting the child devices when EDR event is + * received from firmware. + */ +static void dpc_disconnect_devices(struct pci_dev *dev) +{ + struct pci_dev *udev; + struct pci_bus *parent; + struct pci_dev *pdev, *temp; + + dev_dbg(&dev->dev, "Disconnecting the child devices\n"); + + if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) + udev = dev; + else + udev = dev->bus->self; + + parent = udev->subordinate; + pci_walk_bus(parent, pci_dev_set_disconnected, NULL); + + pci_lock_rescan_remove(); + pci_dev_get(dev); + list_for_each_entry_safe_reverse(pdev, temp, &parent->devices, + bus_list) { + pci_stop_and_remove_bus_device(pdev); + } + pci_dev_put(dev); + pci_unlock_rescan_remove(); +} + +static void edr_handle_event(acpi_handle handle, u32 event, void *data) +{ + struct dpc_dev *dpc = (struct dpc_dev *) data; + struct pci_dev *pdev; + u16 status, cap; + + if (event != ACPI_NOTIFY_DISCONNECT_RECOVER) + return; + + if (!data) { + pr_err("Invalid EDR event\n"); + return; + } + + dev_dbg(&dpc->dev->port->dev, "Valid EDR event received\n"); + + /* + * Check if _DSM(0xD) is available, and if present locate the + * port which issued EDR event. + */ + pdev = acpi_locate_dpc_port(dpc); + if (!pdev) { + dev_err(&dpc->dev->port->dev, "No valid port found\n"); + return; + } + + /* + * Get DPC priv data for given pdev + */ + dpc = to_dpc_dev(pdev); + dpc->error_state = PCI_ERS_RESULT_DISCONNECT; + pdev = dpc->dev->port; + cap = dpc->cap_pos; + + /* + * Check if the port supports DPC: + * + * if port does not support DPC, then let firmware handle + * the error recovery and OS is responsible for cleaning + * up the child devices. + * + * if port supports DPC, then fall back to default error + * recovery. + * + */ + if (cap) { + /* Check if there is a valid DPC trigger */ + pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status); + if (!(status & PCI_EXP_DPC_STATUS_TRIGGER)) { + dev_err(&pdev->dev, "Invalid DPC trigger\n"); + return; + } + dpc_process_error(dpc); + } + + if (dpc->error_state == PCI_ERS_RESULT_RECOVERED) { + /* + * Recovery is successful, so send + * _OST(0xF, BDF << 16 | 0x80, "") to firmware. + */ + status = 0x80; + } else { + /* + * Recovery is not successful, so disconnect child devices + * and send _OST(0xF, BDF << 16 | 0x81, "") to firmware. + */ + dpc_disconnect_devices(pdev); + status = 0x81; + } + + acpi_send_edr_status(dpc, status); +} + +#endif + #define FLAG(x, y) (((x) & (y)) ? '+' : '-') static int dpc_probe(struct pcie_device *dev) { @@ -291,9 +543,10 @@ static int dpc_probe(struct pcie_device *dev) struct device *device = &dev->device; int status; u16 ctl, cap; - - if (pcie_aer_get_firmware_first(pdev)) - return -ENOTSUPP; +#ifdef CONFIG_ACPI + struct acpi_device *adev = ACPI_COMPANION(&pdev->dev); + acpi_status astatus; +#endif dpc = devm_kzalloc(device, sizeof(*dpc), GFP_KERNEL); if (!dpc) @@ -302,16 +555,53 @@ static int dpc_probe(struct pcie_device *dev) dpc->cap_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DPC); dpc->dev = dev; set_service_data(dev, dpc); + dpc->error_state = PCI_ERS_RESULT_NONE; + + if (!pcie_aer_get_firmware_first(pdev)) + if (pci_aer_available() && dpc->cap_pos) + dpc->native_dpc = 1; - status = devm_request_threaded_irq(device, dev->irq, dpc_irq, - dpc_handler, IRQF_SHARED, - "pcie-dpc", dpc); - if (status) { - dev_warn(device, "request IRQ%d failed: %d\n", dev->irq, - status); - return status; + /* + * If native support is not enabled and ACPI is not + * enabled then return error. + */ + if (!dpc->native_dpc && !IS_ENABLED(CONFIG_APCI)) + return -ENODEV; + + if (dpc->native_dpc) { + status = devm_request_threaded_irq(device, dev->irq, dpc_irq, + dpc_handler, IRQF_SHARED, + "pcie-dpc", dpc); + if (status) { + dev_warn(device, "request IRQ%d failed: %d\n", dev->irq, + status); + return status; + } } +#ifdef CONFIG_ACPI + if (!dpc->native_dpc) { + if (!adev) { + dev_err(device, "No valid acpi device found\n"); + return -ENODEV; + } + + dpc->adev = adev; + + /* Register ACPI notifier for EDR event */ + astatus = acpi_install_notify_handler(adev->handle, + ACPI_SYSTEM_NOTIFY, + edr_handle_event, + dpc); + + if (ACPI_FAILURE(astatus)) { + dev_err(device, "Install notifier failed\n"); + return -EBUSY; + } + + acpi_enable_dpc_port(dpc, true); + } +#endif pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CAP, &cap); pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, &ctl); @@ -325,8 +615,12 @@ static int dpc_probe(struct pcie_device *dev) } } - ctl = (ctl & 0xfff4) | 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); + if (dpc->native_dpc) { + ctl = (ctl & 0xfff4) | 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); + } dev_info(device, "DPC error containment capabilities: Int Msg #%d, RPExt%c PoisonedTLP%c SwTrigger%c RP PIO Log %d, DL_ActiveErr%c\n", cap & PCI_EXP_DPC_IRQ, FLAG(cap, PCI_EXP_DPC_CAP_RP_EXT), @@ -344,6 +638,9 @@ static void dpc_remove(struct pcie_device *dev) struct pci_dev *pdev = dev->port; u16 ctl; + if (!dpc->native_dpc) + return; + 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); @@ -356,6 +653,7 @@ static struct pcie_port_service_driver dpcdriver = { .probe = dpc_probe, .remove = dpc_remove, .reset_link = dpc_reset_link, + .error_resume = dpc_error_resume, }; int __init pcie_dpc_init(void) diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c index 865f12f4b314..050cbb7a5083 100644 --- a/drivers/pci/pcie/portdrv_core.c +++ b/drivers/pci/pcie/portdrv_core.c @@ -249,9 +249,14 @@ static int get_port_device_capability(struct pci_dev *dev) pcie_pme_interrupt_enable(dev, false); } + /* + * If EDR support is enabled in OS, then even if AER is not handled in + * OS, DPC service can be enabled. + */ if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC) && - pci_aer_available() && services & PCIE_PORT_SERVICE_AER && - (pcie_ports_native || host->native_dpc)) + ((IS_ENABLED(CONFIG_PCIE_EDR) && !host->native_dpc) || + (pci_aer_available() && services & PCIE_PORT_SERVICE_AER && + (pcie_ports_native || host->native_dpc)))) services |= PCIE_PORT_SERVICE_DPC; if (pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM || -- 2.20.1
