bus: omap_l3_noc: Add information about the context of operation

L3 error may be triggered using Debug interface (example JTAG) or
due to other errors, for example an opcode fetch (due to function
pointer or stack corruption) or a data access (due to some other
failure). NOC registers contain additional information to help aid
debug information.

With this, we can enhance the error information to more detailed form:
"
L3 Custom Error: MASTER MPU TARGET L4PER2 (Read): Data Access in User mode
during Functional access
"
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Darren Etheridge <detheridge@ti.com>
Tested-by: Sekhar Nori <nsekhar@ti.com>

drivers/bus/omap_l3_noc.c

@@ -60,15 +60,16 @@ static int l3_handle_target(struct omap_l3 *l3, void __iomem *base,
 {
 	int k;
 	u32 std_err_main, clear, masterid;
-	u8 op_code;
+	u8 op_code, m_req_info;
 	void __iomem *l3_targ_base;
 	void __iomem *l3_targ_stderr, *l3_targ_slvofslsb, *l3_targ_mstaddr;
-	void __iomem *l3_targ_hdr;
+	void __iomem *l3_targ_hdr, *l3_targ_info;
 	struct l3_target_data *l3_targ_inst;
 	struct l3_masters_data *master;
 	char *target_name, *master_name = "UN IDENTIFIED";
 	char *err_description;
 	char err_string[30] = { 0 };
+	char info_string[60] = { 0 };
 
 	/* We DONOT expect err_src to go out of bounds */
 	BUG_ON(err_src > MAX_CLKDM_TARGETS);
@@ -99,6 +100,7 @@ static int l3_handle_target(struct omap_l3 *l3, void __iomem *base,
 
 		l3_targ_mstaddr = l3_targ_base + L3_TARG_STDERRLOG_MSTADDR;
 		l3_targ_hdr = l3_targ_base + L3_TARG_STDERRLOG_HDR;
+		l3_targ_info = l3_targ_base + L3_TARG_STDERRLOG_INFO;
 		break;
 
 	case CUSTOM_ERROR:
@@ -107,6 +109,7 @@ static int l3_handle_target(struct omap_l3 *l3, void __iomem *base,
 		l3_targ_mstaddr = l3_targ_base +
 				  L3_TARG_STDERRLOG_CINFO_MSTADDR;
 		l3_targ_hdr = l3_targ_base + L3_TARG_STDERRLOG_CINFO_OPCODE;
+		l3_targ_info = l3_targ_base + L3_TARG_STDERRLOG_CINFO_INFO;
 		break;
 
 	default:
@@ -128,13 +131,20 @@ static int l3_handle_target(struct omap_l3 *l3, void __iomem *base,
 
 	op_code = readl_relaxed(l3_targ_hdr) & 0x7;
 
+	m_req_info = readl_relaxed(l3_targ_info) & 0xF;
+	snprintf(info_string, sizeof(info_string),
+		 ": %s in %s mode during %s access",
+		 (m_req_info & BIT(0)) ? "Opcode Fetch" : "Data Access",
+		 (m_req_info & BIT(1)) ? "Supervisor" : "User",
+		 (m_req_info & BIT(3)) ? "Debug" : "Functional");
+
 	WARN(true,
-	     "%s:L3 %s Error: MASTER %s TARGET %s (%s)%s\n",
+	     "%s:L3 %s Error: MASTER %s TARGET %s (%s)%s%s\n",
 	     dev_name(l3->dev),
 	     err_description,
 	     master_name, target_name,
 	     l3_transaction_type[op_code],
-	     err_string);
+	     err_string, info_string);
 
 	/* clear the std error log*/
 	clear = std_err_main | CLEAR_STDERR_LOG;

drivers/bus/omap_l3_noc.h

@@ -31,7 +31,9 @@
 #define L3_TARG_STDERRLOG_MAIN		0x48
 #define L3_TARG_STDERRLOG_HDR		0x4c
 #define L3_TARG_STDERRLOG_MSTADDR	0x50
+#define L3_TARG_STDERRLOG_INFO		0x58
 #define L3_TARG_STDERRLOG_SLVOFSLSB	0x5c
+#define L3_TARG_STDERRLOG_CINFO_INFO	0x64
 #define L3_TARG_STDERRLOG_CINFO_MSTADDR	0x68
 #define L3_TARG_STDERRLOG_CINFO_OPCODE	0x6c
 #define L3_FLAGMUX_REGERR0		0xc