[PATCH 2/2] EDAC/igen6: Add polling support

[Orange Kao]

I have a PC with Intel N100 (with PCI device 8086:461c, DID_ADL_N_SKU4)
but interrupt does not seems to work, even with the following
configuration in BIOS. I am not sure if this is caused by a BIOS bug or
not.

    In-Band ECC Support: Enabled
    In-Band ECC Operation Mode: 2 (make all requests protected and
                                  ignore range checks)
    IBECC Error Injection Control: Inject Correctable Error on insertion
                                   counter
    Error Injaction Insertion Count: 251658240 (0xf000000)

This commit tried to add polling support.
---
 drivers/edac/igen6_edac.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/edac/igen6_edac.c b/drivers/edac/igen6_edac.c
index 07dacf8c10be..5027070410a5 100644
--- a/drivers/edac/igen6_edac.c
+++ b/drivers/edac/igen6_edac.c
@@ -1170,6 +1170,19 @@ static int igen6_pci_setup(struct pci_dev *pdev, u64 *mchbar)
 	return -ENODEV;
 }
 
+static void igen6_check(struct mem_ctl_info *mci)
+{
+	struct igen6_imc *imc = mci->pvt_info;
+
+	/* errsts_clear() isn't NMI-safe. Delay it in the IRQ context */
+	u64 ecclog = ecclog_read_and_clear(imc);
+	if (!ecclog)
+		return;
+	if (!ecclog_gen_pool_add(imc->mc, ecclog))
+		irq_work_queue(&ecclog_irq_work);
+
+}
+
 static int igen6_register_mci(int mc, u64 mchbar, struct pci_dev *pdev)
 {
 	struct edac_mc_layer layers[2];
@@ -1211,6 +1224,9 @@ static int igen6_register_mci(int mc, u64 mchbar, struct pci_dev *pdev)
 	mci->edac_cap = EDAC_FLAG_SECDED;
 	mci->mod_name = EDAC_MOD_STR;
 	mci->dev_name = pci_name(pdev);
+	if (edac_op_state == EDAC_OPSTATE_POLL) {
+		mci->edac_check = igen6_check;
+	}
 	mci->pvt_info = &igen6_pvt->imc[mc];
 
 	imc = mci->pvt_info;
@@ -1450,7 +1466,9 @@ static int __init igen6_init(void)
 	if (owner && strncmp(owner, EDAC_MOD_STR, sizeof(EDAC_MOD_STR)))
 		return -EBUSY;
 
-	edac_op_state = EDAC_OPSTATE_NMI;
+	if (edac_op_state == EDAC_OPSTATE_INVAL) {
+		edac_op_state = EDAC_OPSTATE_NMI;
+	}
 
 	rc = pci_register_driver(&igen6_driver);
 	if (rc)
@@ -1474,3 +1492,6 @@ module_exit(igen6_exit);
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Qiuxu Zhuo");
 MODULE_DESCRIPTION("MC Driver for Intel client SoC using In-Band ECC");
+
+module_param(edac_op_state, int, 0444);
+MODULE_PARM_DESC(edac_op_state, "EDAC Error Reporting state: 0=Poll,1=NMI. Default=1");
-- 
2.47.0