[PATCH 05/13] scsi: hisi_sas: shutdown axi bus to avoid exception CQ returned

[John Garry <john.garry@huawei.com>]

From: Xiang Chen <chenxiang66@hisilicon.com>

When injecting 2 bit ECC error, it will cause fatal AXI interrupts. Before
the recovery of SAS controller reset, the internal of SAS controller is in
error. If CQ interrupts return at the time, actually it is exception CQ
interrupt, and it may cause resource release in disorder.

To avoid the exception situation, shutdown AXI bus after fatal AXI
interrupt. In SAS controller reset, it will restart AXI bus. For later
version of v3 hw, hardware will shutdown AXI bus for this situation, so just
fix current ver of v3 hw.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
---
 drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index 726ac4bd..d5eabfc 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -1646,6 +1646,7 @@ static irqreturn_t fatal_axi_int_v3_hw(int irq_no, void *p)
 	u32 irq_value, irq_msk;
 	struct hisi_hba *hisi_hba = p;
 	struct device *dev = hisi_hba->dev;
+	struct pci_dev *pdev = hisi_hba->pci_dev;
 	int i;
 
 	irq_msk = hisi_sas_read32(hisi_hba, ENT_INT_SRC_MSK3);
@@ -1677,6 +1678,17 @@ static irqreturn_t fatal_axi_int_v3_hw(int irq_no, void *p)
 				error->msg, irq_value);
 			queue_work(hisi_hba->wq, &hisi_hba->rst_work);
 		}
+
+		if (pdev->revision < 0x21) {
+			u32 reg_val;
+
+			reg_val = hisi_sas_read32(hisi_hba,
+						  AXI_MASTER_CFG_BASE +
+						  AM_CTRL_GLOBAL);
+			reg_val |= AM_CTRL_SHUTDOWN_REQ_MSK;
+			hisi_sas_write32(hisi_hba, AXI_MASTER_CFG_BASE +
+					 AM_CTRL_GLOBAL, reg_val);
+		}
 	}
 
 	if (irq_value & BIT(ENT_INT_SRC3_ITC_INT_OFF)) {
-- 
1.9.1