Commit 4f58f0bf authored Apr 27, 2017 by Vaibhav Jain Committed by Michael Ellerman May 02, 2017

cxl: Route eeh events to all drivers in cxl_pci_error_detected()



Fix a boundary condition where in some cases an eeh event that results
in card reset isn't passed on to a driver attached to the virtual PCI
device associated with a slice. This will happen in case when a slice
attached device driver returns a value other than
PCI_ERS_RESULT_NEED_RESET from the eeh error_detected() callback. This
would result in an early return from cxl_pci_error_detected() and
other drivers attached to other AFUs on the card wont be notified.

The patch fixes this by making sure that all slice attached
device-drivers are notified and the return values from
error_detected() callback are aggregated in a scheme where request for
'disconnect' trumps all and 'none' trumps 'need_reset'.

Fixes: 9e8df8a2 ("cxl: EEH support")
Cc: stable@vger.kernel.org # v4.3+
Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

parent ea9a26d1

drivers/misc/cxl/pci.c

+9 −6

Original line number	Diff line number	Diff line
		@@ -2057,7 +2057,7 @@ static pci_ers_result_t cxl_pci_error_detected(struct pci_dev *pdev,
		{
		struct cxl *adapter = pci_get_drvdata(pdev);
		struct cxl_afu *afu;
		pci_ers_result_t result = PCI_ERS_RESULT_NEED_RESET;
		pci_ers_result_t result = PCI_ERS_RESULT_NEED_RESET, afu_result;
		int i;

		/* At this point, we could still have an interrupt pending.
		@@ -2162,15 +2162,18 @@ static pci_ers_result_t cxl_pci_error_detected(struct pci_dev *pdev,
		for (i = 0; i < adapter->slices; i++) {
		afu = adapter->afu[i];

		result = cxl_vphb_error_detected(afu, state);

		/* Only continue if everyone agrees on NEED_RESET */
		if (result != PCI_ERS_RESULT_NEED_RESET)
		return result;
		afu_result = cxl_vphb_error_detected(afu, state);

		cxl_context_detach_all(afu);
		cxl_ops->afu_deactivate_mode(afu, afu->current_mode);
		pci_deconfigure_afu(afu);

		/* Disconnect trumps all, NONE trumps NEED_RESET */
		if (afu_result == PCI_ERS_RESULT_DISCONNECT)
		result = PCI_ERS_RESULT_DISCONNECT;
		else if ((afu_result == PCI_ERS_RESULT_NONE) &&
		(result == PCI_ERS_RESULT_NEED_RESET))
		result = PCI_ERS_RESULT_NONE;
		}

		/* should take the context lock here */

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