[PATCH v2 12/21] megaraid_sas: Dump system registers for debugging

[Shivasharan S <shivasharan.srikanteshwara@xxxxxxxxxxxx>]

When controller fails to transition to READY state during driver probe,
dump the system interface register set.
This will give snapshot of the firmware status for debugging
driver load issues.

Signed-off-by: Sumit Saxena <sumit.saxena@xxxxxxxxxxxx>
Signed-off-by: Shivasharan S <shivasharan.srikanteshwara@xxxxxxxxxxxx>
---
Changes in v2:
Fixed the sparse warning and removed the endianness conversion after
readl.

 drivers/scsi/megaraid/megaraid_sas_base.c | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index e2a89821bdd2..905b45590c7e 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -2862,6 +2862,24 @@ megasas_dump(void *buf, int sz, int format)
 	printk(KERN_CONT "\n");
 }
 
+/**
+ * megasas_dump_reg_set -	This function will print hexdump of register set
+ * @buf:			Buffer to be dumped
+ * @sz:				Size in bytes
+ * @format:			Different formats of dumping e.g. format=n will
+ *				cause only 'n' 32 bit words to be dumped in a
+ *				single line.
+ */
+inline void
+megasas_dump_reg_set(void __iomem *reg_set)
+{
+	unsigned int i, sz = 256;
+	u32 __iomem *reg = (u32 __iomem *)reg_set;
+
+	for (i = 0; i < (sz / sizeof(u32)); i++)
+		printk("%08x: %08x\n", (i * 4), readl(&reg[i]));
+}
+
 /**
  * megasas_dump_fusion_io -	This function will print key details
  *				of SCSI IO
@@ -3891,8 +3909,11 @@ megasas_transition_to_ready(struct megasas_instance *instance, int ocr)
 				max_wait = MEGASAS_RESET_WAIT_TIME;
 				cur_state = MFI_STATE_FAULT;
 				break;
-			} else
+			} else {
+				dev_printk(KERN_DEBUG, &instance->pdev->dev, "System Register set:\n");
+				megasas_dump_reg_set(instance->reg_set);
 				return -ENODEV;
+			}
 
 		case MFI_STATE_WAIT_HANDSHAKE:
 			/*
@@ -4000,6 +4021,8 @@ megasas_transition_to_ready(struct megasas_instance *instance, int ocr)
 		default:
 			dev_printk(KERN_DEBUG, &instance->pdev->dev, "Unknown state 0x%x\n",
 			       fw_state);
+			dev_printk(KERN_DEBUG, &instance->pdev->dev, "System Register set:\n");
+			megasas_dump_reg_set(instance->reg_set);
 			return -ENODEV;
 		}
 
@@ -4022,6 +4045,8 @@ megasas_transition_to_ready(struct megasas_instance *instance, int ocr)
 		if (curr_abs_state == abs_state) {
 			dev_printk(KERN_DEBUG, &instance->pdev->dev, "FW state [%d] hasn't changed "
 			       "in %d secs\n", fw_state, max_wait);
+			dev_printk(KERN_DEBUG, &instance->pdev->dev, "System Register set:\n");
+			megasas_dump_reg_set(instance->reg_set);
 			return -ENODEV;
 		}
 
-- 
2.16.1