ARM: socfpga: Enable Arria10 L2 cache ECC on startup

Enable ECC for Arria10 L2 cache on machine startup. The ECC has to be
enabled before data is stored in memory otherwise the ECC will fail on
reads.

Use DT_MACHINE to select Arria10 L2 cache function.

Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
Acked-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Cc: devicetree@vger.kernel.org
Cc: dinguyen@opensource.altera.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux@arm.linux.org.uk
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1458576106-24505-9-git-send-email-tthayer@opensource.altera.com
Signed-off-by: Borislav Petkov <bp@suse.de>

arch/arm/mach-socfpga/core.h

@@ -38,6 +38,7 @@ extern void socfpga_init_clocks(void);
 extern void socfpga_sysmgr_init(void);
 void socfpga_init_l2_ecc(void);
 void socfpga_init_ocram_ecc(void);
+void socfpga_init_arria10_l2_ecc(void);
 
 extern void __iomem *sys_manager_base_addr;
 extern void __iomem *rst_manager_base_addr;

arch/arm/mach-socfpga/l2_cache.c

@@ -17,6 +17,20 @@
 #include <linux/of_platform.h>
 #include <linux/of_address.h>
 
+#include "core.h"
+
+/* A10 System Manager L2 ECC Control register */
+#define A10_MPU_CTRL_L2_ECC_OFST          0x0
+#define A10_MPU_CTRL_L2_ECC_EN            BIT(0)
+
+/* A10 System Manager Global IRQ Mask register */
+#define A10_SYSMGR_ECC_INTMASK_CLR_OFST   0x98
+#define A10_SYSMGR_ECC_INTMASK_CLR_L2     BIT(0)
+
+/* A10 System Manager L2 ECC IRQ Clear register */
+#define A10_SYSMGR_MPU_CLEAR_L2_ECC_OFST  0xA8
+#define A10_SYSMGR_MPU_CLEAR_L2_ECC       (BIT(31) | BIT(15))
+
 void socfpga_init_l2_ecc(void)
 {
 	struct device_node *np;
@@ -39,3 +53,38 @@ void socfpga_init_l2_ecc(void)
 	writel(0x01, mapped_l2_edac_addr);
 	iounmap(mapped_l2_edac_addr);
 }
+
+void socfpga_init_arria10_l2_ecc(void)
+{
+	struct device_node *np;
+	void __iomem *mapped_l2_edac_addr;
+
+	/* Find the L2 EDAC device tree node */
+	np = of_find_compatible_node(NULL, NULL, "altr,socfpga-a10-l2-ecc");
+	if (!np) {
+		pr_err("Unable to find socfpga-a10-l2-ecc in dtb\n");
+		return;
+	}
+
+	mapped_l2_edac_addr = of_iomap(np, 0);
+	of_node_put(np);
+	if (!mapped_l2_edac_addr) {
+		pr_err("Unable to find L2 ECC mapping in dtb\n");
+		return;
+	}
+
+	if (!sys_manager_base_addr) {
+		pr_err("System Mananger not mapped for L2 ECC\n");
+		goto exit;
+	}
+	/* Clear any pending IRQs */
+	writel(A10_SYSMGR_MPU_CLEAR_L2_ECC, (sys_manager_base_addr +
+	       A10_SYSMGR_MPU_CLEAR_L2_ECC_OFST));
+	/* Enable ECC */
+	writel(A10_SYSMGR_ECC_INTMASK_CLR_L2, sys_manager_base_addr +
+	       A10_SYSMGR_ECC_INTMASK_CLR_OFST);
+	writel(A10_MPU_CTRL_L2_ECC_EN, mapped_l2_edac_addr +
+	       A10_MPU_CTRL_L2_ECC_OFST);
+exit:
+	iounmap(mapped_l2_edac_addr);
+}

arch/arm/mach-socfpga/socfpga.c

@@ -66,6 +66,14 @@ static void __init socfpga_init_irq(void)
 		socfpga_init_ocram_ecc();
 }
 
+static void __init socfpga_arria10_init_irq(void)
+{
+	irqchip_init();
+	socfpga_sysmgr_init();
+	if (IS_ENABLED(CONFIG_EDAC_ALTERA_L2C))
+		socfpga_init_arria10_l2_ecc();
+}
+
 static void socfpga_cyclone5_restart(enum reboot_mode mode, const char *cmd)
 {
 	u32 temp;
@@ -113,7 +121,7 @@ static const char *altera_a10_dt_match[] = {
 DT_MACHINE_START(SOCFPGA_A10, "Altera SOCFPGA Arria10")
 	.l2c_aux_val	= 0,
 	.l2c_aux_mask	= ~0,
-	.init_irq	= socfpga_init_irq,
+	.init_irq	= socfpga_arria10_init_irq,
 	.restart	= socfpga_arria10_restart,
 	.dt_compat	= altera_a10_dt_match,
 MACHINE_END