[PATCH 07/13] powerpc/eeh: Clean up pci_ers_result handling
From: Sam Bobroff <hidden>
Date: 2018-05-02 06:36:12
Subsystem:
linux for powerpc (32-bit and 64-bit), pci enhanced error handling (eeh) for powerpc, the rest · Maintainers:
Madhavan Srinivasan, Mahesh J Salgaonkar, Linus Torvalds
As EEH event handling progresses, a cumulative result of type pci_ers_result is built up by (some of) the eeh_report_*() functions using either: if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc; if (*res == PCI_ERS_RESULT_NONE) *res = rc; or: if ((*res == PCI_ERS_RESULT_NONE) || (*res == PCI_ERS_RESULT_RECOVERED)) *res = rc; if (*res == PCI_ERS_RESULT_DISCONNECT && rc == PCI_ERS_RESULT_NEED_RESET) *res = rc; (Where *res is the accumulator.) However, the intent is not immediately clear and the result in some situations is order dependent. Address this by assigning a priority to each result value, and always merging to the highest priority. This renders the intent clear, and provides a stable value for all orderings. Signed-off-by: Sam Bobroff <redacted> --- arch/powerpc/kernel/eeh_driver.c | 36 ++++++++++++++++++++++++++---------- 1 file changed, 26 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c
index 188d15c4fe3a..f33dd68a9ca2 100644
--- a/arch/powerpc/kernel/eeh_driver.c
+++ b/arch/powerpc/kernel/eeh_driver.c@@ -39,6 +39,29 @@ struct eeh_rmv_data { int removed; }; +static int eeh_result_priority(enum pci_ers_result result) +{ + switch (result) { + case PCI_ERS_RESULT_NONE: return 0; + case PCI_ERS_RESULT_NO_AER_DRIVER: return 1; + case PCI_ERS_RESULT_RECOVERED: return 2; + case PCI_ERS_RESULT_CAN_RECOVER: return 3; + case PCI_ERS_RESULT_DISCONNECT: return 4; + case PCI_ERS_RESULT_NEED_RESET: return 5; + default: + WARN_ONCE(1, "Unknown pci_ers_result value"); + return 0; + } +}; + +static enum pci_ers_result merge_result(enum pci_ers_result old, + enum pci_ers_result new) +{ + if (eeh_result_priority(new) > eeh_result_priority(old)) + return new; + return old; +} + /** * eeh_pcid_get - Get the PCI device driver * @pdev: PCI device
@@ -206,9 +229,7 @@ static void *eeh_report_error(struct eeh_dev *edev, void *userdata) rc = driver->err_handler->error_detected(dev, pci_channel_io_frozen); - /* A driver that needs a reset trumps all others */ - if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc; - if (*res == PCI_ERS_RESULT_NONE) *res = rc; + *res = merge_result(*res, rc); edev->in_error = true; pci_uevent_ers(dev, PCI_ERS_RESULT_NONE);
@@ -249,9 +270,7 @@ static void *eeh_report_mmio_enabled(struct eeh_dev *edev, void *userdata) rc = driver->err_handler->mmio_enabled(dev); - /* A driver that needs a reset trumps all others */ - if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc; - if (*res == PCI_ERS_RESULT_NONE) *res = rc; + *res = merge_result(*res, rc); out: eeh_pcid_put(dev);
@@ -294,10 +313,7 @@ static void *eeh_report_reset(struct eeh_dev *edev, void *userdata) goto out; rc = driver->err_handler->slot_reset(dev); - if ((*res == PCI_ERS_RESULT_NONE) || - (*res == PCI_ERS_RESULT_RECOVERED)) *res = rc; - if (*res == PCI_ERS_RESULT_DISCONNECT && - rc == PCI_ERS_RESULT_NEED_RESET) *res = rc; + *res = merge_result(*res, rc); out: eeh_pcid_put(dev);
--
2.16.1.74.g9b0b1f47b