arm: socfpga: stratix10: Add cpu_has_been_warmreset()

Add helper function cpu_has_been_warmreset() to check
if CPU is from warm reset boot.
Signed-off-by: NLey Foon Tan <ley.foon.tan@intel.com>

arch/arm/mach-socfpga/include/mach/reset_manager_s10.h

@@ -9,6 +9,7 @@
 
 void reset_cpu(ulong addr);
 void reset_deassert_peripherals_handoff(void);
+int cpu_has_been_warmreset(void);
 
 void socfpga_bridges_reset(int enable);
 
@@ -47,6 +48,8 @@ struct socfpga_reset_manager {
 #define RSTMGR_MPUMODRST_CORE0		0
 #define RSTMGR_PER0MODRST_OCP_MASK	0x0020bf00
 #define RSTMGR_BRGMODRST_DDRSCH_MASK	0X00000040
+/* Watchdogs and MPU warm reset mask */
+#define RSTMGR_L4WD_MPU_WARMRESET_MASK	0x000F0F00
 
 /*
  * Define a reset identifier, from which a permodrst bank ID

arch/arm/mach-socfpga/reset_manager_s10.c

@@ -103,3 +103,12 @@ void reset_deassert_peripherals_handoff(void)
 	writel(~RSTMGR_PER0MODRST_OCP_MASK, &reset_manager_base->per0modrst);
 	writel(0, &reset_manager_base->per0modrst);
 }
+
+/*
+ * Return non-zero if the CPU has been warm reset
+ */
+int cpu_has_been_warmreset(void)
+{
+	return readl(&reset_manager_base->status) &
+		RSTMGR_L4WD_MPU_WARMRESET_MASK;
+}