PCI/ERR: Remove service dependency in pcie_do_recovery()

Previously we passed the PCIe service type parameter to pcie_do_recovery(),
where reset_link() looked up the underlying pci_port_service_driver and its
.reset_link() function pointer. Instead of using this roundabout way, we
can just pass the driver-specific .reset_link() callback function when
calling pcie_do_recovery() function.

This allows us to call pcie_do_recovery() from code that is not a PCIe port
service driver, e.g., Error Disconnect Recover (EDR) support.

Remove pcie_port_find_service() and pcie_port_service_driver.reset_link
since they are now unused.

Link: https://lore.kernel.org/r/60e02b87b526cdf2930400059d98704bf0a147d1.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 4 insertions, 15 deletions

diff --git a/Documentation/PCI/pcieaer-howto.rst b/Documentation/PCI/pcieaer-howto.rst
index 18bdefaafd1a..afbd8c1c321d 100644
--- a/Documentation/PCI/pcieaer-howto.rst
+++ b/Documentation/PCI/pcieaer-howto.rst
@@ -156,12 +156,6 @@ default reset_link function, but different upstream ports might
 have different specifications to reset pci express link, so all
 upstream ports should provide their own reset_link functions.
 
-In struct pcie_port_service_driver, a new pointer, reset_link, is
-added.
-::
-
-	pci_ers_result_t (*reset_link) (struct pci_dev *dev);
-
 Section 3.2.2.2 provides more detailed info on when to call
 reset_link.
 
@@ -212,15 +206,10 @@ error_detected(dev, pci_channel_io_frozen) to all drivers within
 a hierarchy in question. Then, performing link reset at upstream is
 necessary. As different kinds of devices might use different approaches
 to reset link, AER port service driver is required to provide the
-function to reset link. Firstly, kernel looks for if the upstream
-component has an aer driver. If it has, kernel uses the reset_link
-callback of the aer driver. If the upstream component has no aer driver
-and the port is downstream port, we will perform a hot reset as the
-default by setting the Secondary Bus Reset bit of the Bridge Control
-register associated with the downstream port. As for upstream ports,
-they should provide their own aer service drivers with reset_link
-function. If error_detected returns PCI_ERS_RESULT_CAN_RECOVER and
-reset_link returns PCI_ERS_RESULT_RECOVERED, the error handling goes
+function to reset link via callback parameter of pcie_do_recovery()
+function. If reset_link is not NULL, recovery function will use it
+to reset the link. If error_detected returns PCI_ERS_RESULT_CAN_RECOVER
+and reset_link returns PCI_ERS_RESULT_RECOVERED, the error handling goes
 to mmio_enabled.
 
 helper functions