@@ -143,3 +143,13 @@ 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.
@@ -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;
@@ -202,10 +224,9 @@ static void dpc_process_rp_pio_error(struct dpc_dev *dpc)
pci_write_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_STATUS, status);
}
-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;
@@ -236,6 +257,13 @@ 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;
}
@@ -258,6 +286,230 @@ 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_ERROR_DISCONNECT,
+ 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_ERROR_DISCONNECT)
+ 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)
{
@@ -266,9 +518,10 @@ 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)
@@ -277,16 +530,53 @@ 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;
- 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 (!pcie_aer_get_firmware_first(pdev))
+ if (pci_aer_available() && dpc->cap_pos)
+ dpc->native_dpc = 1;
+
+ /*
+ * 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);
@@ -300,8 +590,12 @@ 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),
@@ -319,6 +613,9 @@ 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);
@@ -331,6 +628,7 @@ 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)
@@ -246,9 +246,14 @@ 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;
return services;