Re: [PATCHv4 2/5] arm: socfpga: Enable OCRAM ECC on startup.

Thor Thayer <tthayer@xxxxxxxxxxxxxxxxxxxxx> · Fri, 7 Nov 2014 16:11:27 -0600

Hi Dinh,

On 11/07/2014 02:32 PM, Dinh Nguyen wrote:
Hi Thor,

On 11/07/2014 10:54 AM, tthayer@xxxxxxxxxxxxxxxxxxxxx wrote:
From: Thor Thayer <tthayer@xxxxxxxxxxxxxxxxxxxxx>

This patch enables the ECC for On-Chip RAM on machine
startup.  The ECC has to be enabled before data is
is stored in memory otherwise the ECC will fail on
reads.

Signed-off-by: Thor Thayer <tthayer@xxxxxxxxxxxxxxxxxxxxx>
---
v2: Split OCRAM ECC portion separately. Addition of iounmap()
and reorganization of gen_pool_free. Remove defconfig from patch.

v3/4: No change
---
  MAINTAINERS                     |    1 +
  arch/arm/mach-socfpga/Makefile  |    1 +
  arch/arm/mach-socfpga/ocram.c   |   90 +++++++++++++++++++++++++++++++++++++++
  arch/arm/mach-socfpga/ocram.h   |   28 ++++++++++++
  arch/arm/mach-socfpga/socfpga.c |    8 ++++
  5 files changed, 128 insertions(+)
  create mode 100644 arch/arm/mach-socfpga/ocram.c
  create mode 100644 arch/arm/mach-socfpga/ocram.h

diff --git a/MAINTAINERS b/MAINTAINERS
index d0c7752..c6d390e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1408,6 +1408,7 @@ M:	Thor Thayer <tthayer@xxxxxxxxxxxxxxxxxxxxx>
  S:	Maintained
  F:	drivers/edac/altera_edac.
  F:	arch/arm/mach-socfpga/l2_cache.*
+F:	arch/arm/mach-socfpga/ocram.*
I think you can remove these entries for l2_cache.c and ocram.c since it
already falls under mach-socfpga/, which I already maintain.

Thanks. I will remove them.
  
  ARM/STI ARCHITECTURE
  M:	Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxx>
diff --git a/arch/arm/mach-socfpga/Makefile b/arch/arm/mach-socfpga/Makefile
index 142609e..1552ca5 100644
--- a/arch/arm/mach-socfpga/Makefile
+++ b/arch/arm/mach-socfpga/Makefile
@@ -5,3 +5,4 @@
  obj-y					:= socfpga.o
  obj-$(CONFIG_SMP)	+= headsmp.o platsmp.o
  obj-$(CONFIG_EDAC_ALTERA_L2C) += l2_cache.o
+obj-$(CONFIG_EDAC_ALTERA_OCRAM) += ocram.o
diff --git a/arch/arm/mach-socfpga/ocram.c b/arch/arm/mach-socfpga/ocram.c
new file mode 100644
index 0000000..9136009
--- /dev/null
+++ b/arch/arm/mach-socfpga/ocram.c
@@ -0,0 +1,90 @@
+/*
+ * Copyright Altera Corporation (C) 2014. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/clk-provider.h>
Why clk-provider.h and not io.h?

I will change to io.h.
+#include <linux/genalloc.h>
+#include <linux/of_platform.h>
+
+#include "ocram.h"
+
+void socfpga_init_ocram_ecc(void)
+{
+	struct device_node *np;
+	const __be32 *prop;
+	u32 ocr_edac_addr, iram_addr, len;
+	void __iomem  *mapped_ocr_edac_addr;
+	size_t size;
+	struct gen_pool *gp;
+
+	np = of_find_compatible_node(NULL, NULL, "altr,ocram-edac");
+	if (!np) {
+		pr_err("SOCFPGA: Unable to find altr,ocram-edac in dtb\n");
+		return;
+	}
+
+	prop = of_get_property(np, "reg", &size);
+	ocr_edac_addr = be32_to_cpup(prop++);
+	len = be32_to_cpup(prop);
You should be checking for prop before calling be32_to_cpup.

+	if (!prop || size < sizeof(*prop)) {
Then you don't need check for prop here.

+		pr_err("SOCFPGA: Unable to find OCRAM ECC mapping in dtb\n");
+		return;
+	}
+
+	gp = of_get_named_gen_pool(np, "iram", 0);
+	if (!gp) {
+		pr_err("SOCFPGA: OCRAM cannot find gen pool\n");
+		return;
+	}
+
+	np = of_find_compatible_node(NULL, NULL, "mmio-sram");
+	if (!np) {
+		pr_err("SOCFPGA: Unable to find mmio-sram in dtb\n");
+		return;
+	}
+	/* Determine the OCRAM address and size */
+	prop = of_get_property(np, "reg", &size);
+	iram_addr = be32_to_cpup(prop++);
+	len = be32_to_cpup(prop);
Same comment here for checking prop before calling be32_to_cpu.

Good catch. Thanks.
+
+	if (!prop || size < sizeof(*prop)) {
+		pr_err("SOCFPGA: Unable to find OCRAM mapping in dtb\n");
+		return;
+	}
+
+	iram_addr = gen_pool_alloc(gp, len);
+	if (iram_addr == 0) {
+		pr_err("SOCFPGA: cannot alloc from gen pool\n");
+		return;
+	}
+
+	memset((void *)iram_addr, 0, len);
+
+	gen_pool_free(gp, iram_addr, len);
+
+	mapped_ocr_edac_addr = ioremap(ocr_edac_addr, 4);
+	if (!mapped_ocr_edac_addr) {
+		pr_err("SOCFPGA: Unable to map OCRAM ecc regs.\n");
+		return;
+	}
+
+	/* Clear any pending OCRAM ECC interrupts, then enable ECC */
+	writel(0x18, mapped_ocr_edac_addr);
+	writel(0x19, mapped_ocr_edac_addr);
Can you add a define for 0x18 and 0x19? What do these values mean?

Sure.
+
+	iounmap(mapped_ocr_edac_addr);
+
+	pr_debug("SOCFPGA: Success Initializing OCRAM\n");
+}
+
diff --git a/arch/arm/mach-socfpga/ocram.h b/arch/arm/mach-socfpga/ocram.h
new file mode 100644
index 0000000..f93cf84
--- /dev/null
+++ b/arch/arm/mach-socfpga/ocram.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright Altera Corporation (C) 2014. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef MACH_SOCFPGA_OCRAM_H
+#define MACH_SOCFPGA_OCRAM_H
+
+#ifdef CONFIG_EDAC_ALTERA_OCRAM
+void socfpga_init_ocram_ecc(void);
+#else
+inline void socfpga_init_ocram_ecc(void)
+{
+}
+#endif
+
+#endif /* #ifndef MACH_SOCFPGA_OCRAM_H */
diff --git a/arch/arm/mach-socfpga/socfpga.c b/arch/arm/mach-socfpga/socfpga.c
index af6413a..fb41aca 100644
--- a/arch/arm/mach-socfpga/socfpga.c
+++ b/arch/arm/mach-socfpga/socfpga.c
@@ -101,6 +101,13 @@ static void socfpga_cyclone5_restart(enum reboot_mode mode, const char *cmd)
  	writel(temp, rst_manager_base_addr + SOCFPGA_RSTMGR_CTRL);
  }
  
+static void __init socfpga_cyclone5_init(void)
+{
+	of_platform_populate(NULL, of_default_bus_match_table,
+			     NULL, NULL);
+	socfpga_init_ocram_ecc();
Use IS_ENABLED() here, so you can remove the need to have ocram.h. You
can put the function declaration in core.h.

Dinh

I will make the changes. Thanks!

+}
+
  static const char *altera_dt_match[] = {
  	"altr,socfpga",
  	NULL
@@ -112,6 +119,7 @@ DT_MACHINE_START(SOCFPGA, "Altera SOCFPGA")
  	.smp		= smp_ops(socfpga_smp_ops),
  	.map_io		= socfpga_map_io,
  	.init_irq	= socfpga_init_irq,
+	.init_machine	= socfpga_cyclone5_init,
  	.restart	= socfpga_cyclone5_restart,
  	.dt_compat	= altera_dt_match,
  MACHINE_END


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