@@ -12,9 +12,11 @@
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
+#include <linux/pci.h>
#include <linux/pci-ecam.h>
#include <linux/platform_device.h>
+#include "../pci.h"
#include "pci-host-common.h"
static void gen_pci_unmap_cfg(void *ptr)
@@ -96,5 +98,61 @@ void pci_host_common_remove(struct platform_device *pdev)
}
EXPORT_SYMBOL_GPL(pci_host_common_remove);
+#if IS_ENABLED(CONFIG_PCIEAER)
+static pci_ers_result_t pci_host_reset_slot(struct pci_dev *dev)
+{
+ int ret;
+
+ ret = pci_bus_error_reset(dev);
+ if (ret) {
+ pci_err(dev, "Failed to reset slot: %d\n", ret);
+ return PCI_ERS_RESULT_DISCONNECT;
+ }
+
+ pci_info(dev, "Slot has been reset\n");
+
+ return PCI_ERS_RESULT_RECOVERED;
+}
+
+static void pci_host_recover_slots(struct pci_host_bridge *host)
+{
+ struct pci_bus *bus = host->bus;
+ struct pci_dev *dev;
+
+ for_each_pci_bridge(dev, bus) {
+ if (!pci_is_root_bus(bus))
+ continue;
+
+ pcie_do_recovery(dev, pci_channel_io_frozen,
+ pci_host_reset_slot);
+ }
+}
+#else
+static void pci_host_recover_slots(struct pci_host_bridge *host)
+{
+ struct pci_bus *bus = host->bus;
+ struct pci_dev *dev;
+ int ret;
+
+ for_each_pci_bridge(dev, bus) {
+ if (!pci_is_root_bus(bus))
+ continue;
+
+ ret = pci_bus_error_reset(dev);
+ if (ret)
+ pci_err(dev, "Failed to reset slot: %d\n", ret);
+ else
+ pci_info(dev, "Slot has been reset\n");
+ }
+}
+#endif
+
+void pci_host_handle_link_down(struct pci_host_bridge *bridge)
+{
+ dev_info(&bridge->dev, "Recovering slots due to Link Down\n");
+ pci_host_recover_slots(bridge);
+}
+EXPORT_SYMBOL_GPL(pci_host_handle_link_down);
+
MODULE_DESCRIPTION("Common library for PCI host controller drivers");
MODULE_LICENSE("GPL v2");
@@ -12,5 +12,6 @@
int pci_host_common_probe(struct platform_device *pdev);
void pci_host_common_remove(struct platform_device *pdev);
+void pci_host_handle_link_down(struct pci_host_bridge *bridge);
#endif
@@ -5781,6 +5781,7 @@ int pci_bus_error_reset(struct pci_dev *bridge)
mutex_unlock(&pci_slot_mutex);
return pci_bus_reset(bridge->subordinate, PCI_RESET_DO_RESET);
}
+EXPORT_SYMBOL_GPL(pci_bus_error_reset);
/**
* pci_probe_reset_bus - probe whether a PCI bus can be reset
@@ -270,3 +270,4 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
return status;
}
+EXPORT_SYMBOL_GPL(pcie_do_recovery);
The PCI link, when down, needs to be recovered to bring it back. But that cannot be done in a generic way as link recovery procedure is specific to host bridges. So add a new API pci_host_handle_link_down() that could be called by the host bridge drivers when the link goes down. The API will iterate through all the slots and calls the pcie_do_recovery() function with 'pci_channel_io_frozen' as the state. This will result in the execution of the AER Fatal error handling code. Since the link down recovery is pretty much the same as AER Fatal error handling, pcie_do_recovery() helper is reused here. First the AER error_detected callback will be triggered for the bridge and the downstream devices. Then, pci_host_reset_slot() will be called for the slot, which will reset the slot using 'reset_slot' callback to recover the link. Once that's done, resume message will be broadcasted to the bridge and the downstream devices indicating successful link recovery. In case if the AER support is not enabled in the kernel, only pci_bus_error_reset() will be called for each slots as there is no way we could inform the drivers about link recovery. Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> --- drivers/pci/controller/pci-host-common.c | 58 ++++++++++++++++++++++++++++++++ drivers/pci/controller/pci-host-common.h | 1 + drivers/pci/pci.c | 1 + drivers/pci/pcie/err.c | 1 + 4 files changed, 61 insertions(+)