ipq806x: Clear L2 error status register before linux boots.

Previous pending L2 cache errors are cleared during the
cleanup phase before transferring the control to linux.

Change-Id: I3a54c64049135e150c2b49b0d6de1667511b6a14

arch/arm/cpu/armv7/cache_v7.c

@@ -16,6 +16,33 @@
 #define ARMV7_DCACHE_CLEAN_INVAL_RANGE	4
 
 #ifndef CONFIG_SYS_DCACHE_OFF
+
+void set_l2_indirect_reg(u32 reg_addr, u32 val)
+{
+
+        asm volatile ("mcr     p15, 3, %[l2cpselr], c15, c0, 6\n\t"
+                      "isb\n\t"
+                      "mcr     p15, 3, %[l2cpdr],   c15, c0, 7\n\t"
+                      "isb\n\t"
+                        :
+                        : [l2cpselr]"r" (reg_addr), [l2cpdr]"r" (val)
+        );
+}
+
+u32 get_l2_indirect_reg(u32 reg_addr)
+{
+        u32 val;
+
+        asm volatile ("mcr     p15, 3, %[l2cpselr], c15, c0, 6\n\t"
+                      "isb\n\t"
+                      "mrc     p15, 3, %[l2cpdr],   c15, c0, 7\n\t"
+                        : [l2cpdr]"=r" (val)
+                        : [l2cpselr]"r" (reg_addr)
+        );
+
+        return val;
+}
+
 /*
  * Write the level and type you want to Cache Size Selection Register(CSSELR)
  * to get size details from Current Cache Size ID Register(CCSIDR)

arch/arm/cpu/armv7/cpu.c

@@ -75,6 +75,8 @@ int cleanup_before_linux_select(int flags)
 	 */
 	cpu_cache_initialization();
 
+	clear_l2cache_err();
+
 	return 0;
 }
 

board/qca/arm/common/board_init.c

@@ -62,6 +62,20 @@ int board_init(void)
 	int ret;
 	uint32_t start_blocks;
 	uint32_t size_blocks;
+
+#ifdef CONFIG_IPQ_REPORT_L2ERR
+        u32 l2esr;
+
+        /* Record any kind of L2 errors caused during
+         * the previous boot stages as we are clearing
+         * the L2 errors before jumping to linux.
+         * Refer to cleanup_before_linux() */
+#ifndef CONFIG_SYS_DCACHE_OFF
+        l2esr = get_l2_indirect_reg(L2ESR_IND_ADDR);
+#endif
+        report_l2err(l2esr);
+#endif
+
 	qca_smem_flash_info_t *sfi = &qca_smem_flash_info;
 
 	gd->bd->bi_boot_params = QCA_BOOT_PARAMS_ADDR;
@@ -249,6 +263,35 @@ int dram_init(void)
 	return 0;
 }
 
+#ifdef CONFIG_IPQ_REPORT_L2ERR
+void report_l2err(u32 l2esr)
+{
+        if (l2esr & L2ESR_MPDCD)
+                printf("L2 Master port decode error\n");
+
+        if (l2esr & L2ESR_MPSLV)
+                printf("L2 master port slave error\n");
+
+        if (l2esr & L2ESR_TSESB)
+                printf("L2 tag soft error, single-bit\n");
+
+        if (l2esr & L2ESR_TSEDB)
+                printf("L2 tag soft error, double-bit\n");
+
+        if (l2esr & L2ESR_DSESB)
+                printf("L2 data soft error, single-bit\n");
+
+        if (l2esr & L2ESR_DSEDB)
+                printf("L2 data soft error, double-bit\n");
+
+        if (l2esr & L2ESR_MSE)
+                printf("L2 modified soft error\n");
+
+        if (l2esr & L2ESR_MPLDREXNOK)
+                printf("L2 master port LDREX received Normal OK response\n");
+}
+#endif
+
 void enable_caches(void)
 {
 	icache_enable();
@@ -259,7 +302,7 @@ void disable_caches(void)
 	icache_disable();
 }
 
-void clear_l2cache_err(void)
+__weak void clear_l2cache_err(void)
 {
 	return;
 }

board/qca/arm/ipq806x/ipq806x.c

@@ -831,3 +831,19 @@ int ipq_get_tz_version(char *version_name, int buf_size)
 	snprintf(version_name, buf_size, "%s\n", version_name);
 	return 0;
 }
+
+void clear_l2cache_err(void)
+{
+        unsigned int val;
+#ifndef CONFIG_SYS_DCACHE_OFF
+        val = get_l2_indirect_reg(L2ESR_IND_ADDR);
+#endif
+
+#ifdef CONFIG_IPQ_REPORT_L2ERR
+        report_l2err(val);
+#endif
+
+#ifndef CONFIG_SYS_DCACHE_OFF
+        set_l2_indirect_reg(L2ESR_IND_ADDR, val);
+#endif
+}

board/qca/arm/ipq806x/ipq806x.h

@@ -42,6 +42,18 @@
  */
 #define RESET_WDT_BARK_TIME (5 * RESET_WDT_BITE_TIME)
 
+#define L2ESR_IND_ADDR          (0x204)
+
+/* L2ESR bit fields */
+#define L2ESR_MPDCD             BIT(0)
+#define L2ESR_MPSLV             BIT(1)
+#define L2ESR_TSESB             BIT(2)
+#define L2ESR_TSEDB             BIT(3)
+#define L2ESR_DSESB             BIT(4)
+#define L2ESR_DSEDB             BIT(5)
+#define L2ESR_MSE               BIT(6)
+#define L2ESR_MPLDREXNOK        BIT(8)
+
 #define CE1_REG_USAGE           (0)
 #define CE1_ADM_USAGE           (1)
 #define CE1_RESOURCE            (1)

include/common.h

@@ -778,6 +778,10 @@ void	flush_dcache_range(unsigned long start, unsigned long stop);
 void	invalidate_dcache_range(unsigned long start, unsigned long stop);
 void	invalidate_dcache_all(void);
 void	invalidate_icache_all(void);
+void	set_l2_indirect_reg(u32 reg_addr, u32 val);
+void	clear_l2cache_err(void);
+u32	get_l2_indirect_reg(u32 reg_addr);
+void	report_l2err(u32 l2esr);
 
 enum {
 	/* Disable caches (else flush caches but leave them active) */

include/configs/ipq806x.h

@@ -328,7 +328,7 @@ typedef struct {
 
 /* Enabling this flag will report any L2 errors.
  * By default we are disabling it */
-/*#define CONFIG_IPQ_REPORT_L2ERR*/
+#define CONFIG_IPQ_REPORT_L2ERR
 
 /*
  * Location in IMEM which contains the physical address of