diff mbox series

[1/2] drivers/edac: Add L1 and L2 error detection for A53 and A57

Message ID 20200813075721.27981-2-s.hauer@pengutronix.de (mailing list archive)
State New, archived
Headers show
Series Add L1 and L2 error detection for A53 and A57 | expand

Commit Message

Sascha Hauer Aug. 13, 2020, 7:57 a.m. UTC 
The Cortex A53 and A57 cores have error detection capabilities for the
L1/L2 Caches, this patch adds a driver for them.

Unfortunately there is no robust way to inject errors into the caches,
so this driver doesn't contain any code to actually test it. It has
been tested though with code taken from an older version of this driver
found here: https://lkml.org/lkml/2018/3/14/1203. For reasons stated
in this thread the error injection code is not suitable for mainline,
so it is removed from the driver.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 .../bindings/edac/arm,cortex-a5x-edac.yaml    |  32 +++
 drivers/edac/Kconfig                          |   6 +
 drivers/edac/Makefile                         |   1 +
 drivers/edac/cortex_arm64_l1_l2.c             | 208 ++++++++++++++++++
 4 files changed, 247 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/edac/arm,cortex-a5x-edac.yaml
 create mode 100644 drivers/edac/cortex_arm64_l1_l2.c

Comments

Borislav Petkov Aug. 26, 2020, 8:41 a.m. UTC | #1 
On Thu, Aug 13, 2020 at 09:57:20AM +0200, Sascha Hauer wrote:
> The Cortex A53 and A57 cores have error detection capabilities for the
> L1/L2 Caches, this patch adds a driver for them.
> 
> Unfortunately there is no robust way to inject errors into the caches,
> so this driver doesn't contain any code to actually test it. It has
> been tested though with code taken from an older version of this driver
> found here: https://lkml.org/lkml/2018/3/14/1203. For reasons stated
> in this thread the error injection code is not suitable for mainline,
> so it is removed from the driver.
> 
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> ---
>  .../bindings/edac/arm,cortex-a5x-edac.yaml    |  32 +++
>  drivers/edac/Kconfig                          |   6 +
>  drivers/edac/Makefile                         |   1 +
>  drivers/edac/cortex_arm64_l1_l2.c             | 208 ++++++++++++++++++
>  4 files changed, 247 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/edac/arm,cortex-a5x-edac.yaml
>  create mode 100644 drivers/edac/cortex_arm64_l1_l2.c

Just nitpicks below. James'd need to look at this too before it goes
anywhere.

Checkpatch is trying to tell me something here:

WARNING: DT compatible string "arm,cortex-a53-edac" appears un-documented -- check ./Documentation/devicetree/bindings/
#296: FILE: drivers/edac/cortex_arm64_l1_l2.c:190:
+       { .compatible = "arm,cortex-a53-edac" },

WARNING: DT compatible string "arm,cortex-a57-edac" appears un-documented -- check ./Documentation/devicetree/bindings/
#297: FILE: drivers/edac/cortex_arm64_l1_l2.c:191:
+       { .compatible = "arm,cortex-a57-edac" },

for 2/2 too:

WARNING: DT compatible string "arm,cortex-a53-edac" appears un-documented -- check ./Documentation/devicetree/bindings/
#39: FILE: arch/arm64/boot/dts/freescale/fsl-ls1043a.dtsi:842:
+               compatible = "arm,cortex-a53-edac";

WARNING: DT compatible string "arm,cortex-a57-edac" appears un-documented -- check ./Documentation/devicetree/bindings/
#56: FILE: arch/arm64/boot/dts/freescale/fsl-ls1046a.dtsi:805:
+               compatible = "arm,cortex-a57-edac";


False positive or valid?

...

> +static void read_errors(void *data)
> +{
> +	u64 cpumerr, l2merr;
> +	int cpu = smp_processor_id();
> +	char msg[MESSAGE_SIZE];
> +	struct edac_device_ctl_info *edac_ctl = data;

Please sort function local variables declaration in a reverse christmas
tree order:

	<type A> longest_variable_name;
	<type B> shorter_var_name;
	<type C> even_shorter;
	<type D> i;

Check your other functions too pls.

> +	/* cpumerrsr_el1 */
> +	asm volatile("mrs %0, s3_1_c15_c2_2" : "=r" (cpumerr));
> +	asm volatile("msr s3_1_c15_c2_2, %0" :: "r" (0));
> +
> +	if (cpumerr & CPUMERRSR_EL1_VALID) {
> +		const char *str;
> +		int fatal = (cpumerr & CPUMERRSR_EL1_FATAL) != 0;

Don't need "!= 0" and fatal can be bool.

> +		switch (FIELD_GET(CPUMERRSR_EL1_RAMID, cpumerr)) {
> +		case L1_I_TAG_RAM:
> +			str = "L1-I Tag RAM";
> +			break;
> +		case L1_I_DATA_RAM:
> +			str = "L1-I Data RAM";
> +			break;
> +		case L1_D_TAG_RAM:
> +			str = "L1-D Tag RAM";
> +			break;
> +		case L1_D_DATA_RAM:
> +			str = "L1-D Data RAM";
> +			break;
> +		case L1_D_DIRTY_RAM:
> +			str = "L1 Dirty RAM";
> +			break;
> +		case TLB_RAM:
> +			str = "TLB RAM";
> +			break;
> +		default:
> +			str = "unknown";
> +			break;
> +		}
> +
> +		snprintf(msg, MESSAGE_SIZE, "%s %s error(s) on CPU %d",
> +			 str, fatal ? "fatal" : "correctable", cpu);
> +
> +		if (fatal)
> +			edac_device_handle_ue(edac_ctl, 0, 0, msg);
> +		else
> +			edac_device_handle_ce(edac_ctl, 0, 0, msg);
> +	}
> +
> +	/* l2merrsr_el1 */
> +	asm volatile("mrs %0, s3_1_c15_c2_3" : "=r" (l2merr));
> +	asm volatile("msr s3_1_c15_c2_3, %0" :: "r" (0));
> +
> +	if (l2merr & L2MERRSR_EL1_VALID) {
> +		int fatal = (l2merr & L2MERRSR_EL1_FATAL) != 0;

See above.

> +
> +		snprintf(msg, MESSAGE_SIZE, "L2 %s error(s) on CPU %d",
> +			 fatal ? "fatal" : "correctable", cpu);
> +		if (fatal)
> +			edac_device_handle_ue(edac_ctl, 0, 1, msg);
> +		else
> +			edac_device_handle_ce(edac_ctl, 0, 1, msg);
> +	}
> +}

...
Sascha Hauer Oct. 13, 2020, 11:13 a.m. UTC | #2 
Hi Boris,

Sorry for the long delay, your mail was buried in my inbox.

On Wed, Aug 26, 2020 at 10:41:35AM +0200, Borislav Petkov wrote:
> On Thu, Aug 13, 2020 at 09:57:20AM +0200, Sascha Hauer wrote:
> > The Cortex A53 and A57 cores have error detection capabilities for the
> > L1/L2 Caches, this patch adds a driver for them.
> > 
> > Unfortunately there is no robust way to inject errors into the caches,
> > so this driver doesn't contain any code to actually test it. It has
> > been tested though with code taken from an older version of this driver
> > found here: https://lkml.org/lkml/2018/3/14/1203. For reasons stated
> > in this thread the error injection code is not suitable for mainline,
> > so it is removed from the driver.
> > 
> > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> > ---
> >  .../bindings/edac/arm,cortex-a5x-edac.yaml    |  32 +++
> >  drivers/edac/Kconfig                          |   6 +
> >  drivers/edac/Makefile                         |   1 +
> >  drivers/edac/cortex_arm64_l1_l2.c             | 208 ++++++++++++++++++
> >  4 files changed, 247 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/edac/arm,cortex-a5x-edac.yaml
> >  create mode 100644 drivers/edac/cortex_arm64_l1_l2.c
> 
> Just nitpicks below. James'd need to look at this too before it goes
> anywhere.
> 
> Checkpatch is trying to tell me something here:
> 
> WARNING: DT compatible string "arm,cortex-a53-edac" appears un-documented -- check ./Documentation/devicetree/bindings/
> #296: FILE: drivers/edac/cortex_arm64_l1_l2.c:190:
> +       { .compatible = "arm,cortex-a53-edac" },
> 
> WARNING: DT compatible string "arm,cortex-a57-edac" appears un-documented -- check ./Documentation/devicetree/bindings/
> #297: FILE: drivers/edac/cortex_arm64_l1_l2.c:191:
> +       { .compatible = "arm,cortex-a57-edac" },
> 
> for 2/2 too:
> 
> WARNING: DT compatible string "arm,cortex-a53-edac" appears un-documented -- check ./Documentation/devicetree/bindings/
> #39: FILE: arch/arm64/boot/dts/freescale/fsl-ls1043a.dtsi:842:
> +               compatible = "arm,cortex-a53-edac";
> 
> WARNING: DT compatible string "arm,cortex-a57-edac" appears un-documented -- check ./Documentation/devicetree/bindings/
> #56: FILE: arch/arm64/boot/dts/freescale/fsl-ls1046a.dtsi:805:
> +               compatible = "arm,cortex-a57-edac";
> 
> 
> False positive or valid?

Have you run checkpatch on a tree with this patch applied? If not, then
yes, it's undocumented as the docs are added with this patch.

> 
> ...
> 
> > +static void read_errors(void *data)
> > +{
> > +	u64 cpumerr, l2merr;
> > +	int cpu = smp_processor_id();
> > +	char msg[MESSAGE_SIZE];
> > +	struct edac_device_ctl_info *edac_ctl = data;
> 
> Please sort function local variables declaration in a reverse christmas
> tree order:
> 
> 	<type A> longest_variable_name;
> 	<type B> shorter_var_name;
> 	<type C> even_shorter;
> 	<type D> i;

I never heard of such a requirement. How is the length defined? Is it
only the length of the variable name or is it the length of the name
including the type? Including the array braces [] or not? What if a
variable shall be initialized with the value of an earlier declared
variable, do I have to make up variable names with a suitable length in
that case?  What if shorter_var_name and even_shorter are of same type,
can I still write them in a single line? Finally, Is this documented
somewhere?

I hope that was a joke from you that I didn't understand.

> 
> Check your other functions too pls.
> 
> > +	/* cpumerrsr_el1 */
> > +	asm volatile("mrs %0, s3_1_c15_c2_2" : "=r" (cpumerr));
> > +	asm volatile("msr s3_1_c15_c2_2, %0" :: "r" (0));
> > +
> > +	if (cpumerr & CPUMERRSR_EL1_VALID) {
> > +		const char *str;
> > +		int fatal = (cpumerr & CPUMERRSR_EL1_FATAL) != 0;
> 
> Don't need "!= 0" and fatal can be bool.

Ok.

Sascha
Borislav Petkov Oct. 13, 2020, 11:31 a.m. UTC | #3 
On Tue, Oct 13, 2020 at 01:13:46PM +0200, Sascha Hauer wrote:
> Have you run checkpatch on a tree with this patch applied? If not, then
> yes, it's undocumented as the docs are added with this patch.

Aha, I'm usually running checkpatch on the patch itself so if this patch
adds it then checkpatch is doing it wrong. Oh well.

> I never heard of such a requirement. How is the length defined? Is it
> only the length of the variable name or is it the length of the name
> including the type? Including the array braces [] or not?

The total textual length.

>  What if a variable shall be initialized with the value of an earlier
> declared variable, do I have to make up variable names with a suitable
> length in that case?

In that case you should order it so that the initialization is correct.

> What if shorter_var_name and even_shorter are of same type, can I
> still write them in a single line?

You simply sort them so that it remains a reversed xmas tree.

> Finally, Is this documented somewhere?

No, would it make any difference if it were?

> I hope that was a joke from you that I didn't understand.

This is the convention that is used in the tip tree and I'm using it in
the EDAC tree too. Just think of it as a subsystem formatting rule.

Thx.
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/edac/arm,cortex-a5x-edac.yaml b/Documentation/devicetree/bindings/edac/arm,cortex-a5x-edac.yaml
new file mode 100644
index 0000000000000..de9325b688a02
--- /dev/null
+++ b/Documentation/devicetree/bindings/edac/arm,cortex-a5x-edac.yaml
@@ -0,0 +1,32 @@ 
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/edac/arm,cortex-a5x-edac.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM cortex A53/A57 EDAC bindings
+
+description: |+
+  This contains the binding to support error detection for the L1 and L2 caches
+  on ARM Cortex A53 and A57 cores.
+
+properties:
+  compatible:
+    items:
+      - const: arm,cortex-a53-edac
+      - const: arm,cortex-a57-edac
+
+  cpus:
+    minItems: 1
+    description: phandles to the cpu nodes this device handles
+
+required:
+  - compatible
+  - cpus
+
+examples:
+  - |
+    edac-a53 {
+        compatible = "arm,cortex-a53-edac";
+        cpus = <&cpu0 &cpu1 &cpu2 &cpu3>;
+    };
diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
index 7b6ec3014ba2d..19501e5529edd 100644
--- a/drivers/edac/Kconfig
+++ b/drivers/edac/Kconfig
@@ -530,4 +530,10 @@  config EDAC_DMC520
 	  Support for error detection and correction on the
 	  SoCs with ARM DMC-520 DRAM controller.
 
+config EDAC_CORTEX_ARM64_L1_L2
+	tristate "ARM Cortex A57/A53"
+	depends on ARM64
+	help
+	  Support for error detection on ARM Cortex A57 and A53.
+
 endif # EDAC
diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile
index 269e15118ceac..3edba6bea3507 100644
--- a/drivers/edac/Makefile
+++ b/drivers/edac/Makefile
@@ -88,3 +88,4 @@  obj-$(CONFIG_EDAC_QCOM)			+= qcom_edac.o
 obj-$(CONFIG_EDAC_ASPEED)		+= aspeed_edac.o
 obj-$(CONFIG_EDAC_BLUEFIELD)		+= bluefield_edac.o
 obj-$(CONFIG_EDAC_DMC520)		+= dmc520_edac.o
+obj-$(CONFIG_EDAC_CORTEX_ARM64_L1_L2)	+= cortex_arm64_l1_l2.o
diff --git a/drivers/edac/cortex_arm64_l1_l2.c b/drivers/edac/cortex_arm64_l1_l2.c
new file mode 100644
index 0000000000000..12b49a5af3c0f
--- /dev/null
+++ b/drivers/edac/cortex_arm64_l1_l2.c
@@ -0,0 +1,208 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Cortex A57 and A53 EDAC L1 and L2 cache error detection
+ *
+ * Copyright (c) 2020 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de>
+ *
+ * Based on Code from:
+ * Copyright (c) 2018, NXP Semiconductor
+ * Author: York Sun <york.sun@nxp.com>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/of_device.h>
+#include <linux/bitfield.h>
+#include <asm/smp_plat.h>
+
+#include "edac_module.h"
+
+#define EDAC_MOD_STR			"cortex_edac_l1_l2"
+
+#define CPUMERRSR_EL1_RAMID		GENMASK(30, 24)
+
+#define CPUMERRSR_EL1_VALID		BIT(31)
+#define CPUMERRSR_EL1_FATAL		BIT(63)
+
+#define L1_I_TAG_RAM			0x00
+#define L1_I_DATA_RAM			0x01
+#define L1_D_TAG_RAM			0x08
+#define L1_D_DATA_RAM			0x09
+#define L1_D_DIRTY_RAM			0x14
+#define TLB_RAM				0x18
+
+#define L2MERRSR_EL1_VALID		BIT(31)
+#define L2MERRSR_EL1_FATAL		BIT(63)
+
+struct arm64_pvt {
+	call_single_data_t __percpu *csd_check;
+	struct cpumask compat_mask;
+};
+
+#define MESSAGE_SIZE 64
+
+static void read_errors(void *data)
+{
+	u64 cpumerr, l2merr;
+	int cpu = smp_processor_id();
+	char msg[MESSAGE_SIZE];
+	struct edac_device_ctl_info *edac_ctl = data;
+
+	/* cpumerrsr_el1 */
+	asm volatile("mrs %0, s3_1_c15_c2_2" : "=r" (cpumerr));
+	asm volatile("msr s3_1_c15_c2_2, %0" :: "r" (0));
+
+	if (cpumerr & CPUMERRSR_EL1_VALID) {
+		const char *str;
+		int fatal = (cpumerr & CPUMERRSR_EL1_FATAL) != 0;
+
+		switch (FIELD_GET(CPUMERRSR_EL1_RAMID, cpumerr)) {
+		case L1_I_TAG_RAM:
+			str = "L1-I Tag RAM";
+			break;
+		case L1_I_DATA_RAM:
+			str = "L1-I Data RAM";
+			break;
+		case L1_D_TAG_RAM:
+			str = "L1-D Tag RAM";
+			break;
+		case L1_D_DATA_RAM:
+			str = "L1-D Data RAM";
+			break;
+		case L1_D_DIRTY_RAM:
+			str = "L1 Dirty RAM";
+			break;
+		case TLB_RAM:
+			str = "TLB RAM";
+			break;
+		default:
+			str = "unknown";
+			break;
+		}
+
+		snprintf(msg, MESSAGE_SIZE, "%s %s error(s) on CPU %d",
+			 str, fatal ? "fatal" : "correctable", cpu);
+
+		if (fatal)
+			edac_device_handle_ue(edac_ctl, 0, 0, msg);
+		else
+			edac_device_handle_ce(edac_ctl, 0, 0, msg);
+	}
+
+	/* l2merrsr_el1 */
+	asm volatile("mrs %0, s3_1_c15_c2_3" : "=r" (l2merr));
+	asm volatile("msr s3_1_c15_c2_3, %0" :: "r" (0));
+
+	if (l2merr & L2MERRSR_EL1_VALID) {
+		int fatal = (l2merr & L2MERRSR_EL1_FATAL) != 0;
+
+		snprintf(msg, MESSAGE_SIZE, "L2 %s error(s) on CPU %d",
+			 fatal ? "fatal" : "correctable", cpu);
+		if (fatal)
+			edac_device_handle_ue(edac_ctl, 0, 1, msg);
+		else
+			edac_device_handle_ce(edac_ctl, 0, 1, msg);
+	}
+}
+
+static void cortex_arm64_edac_check(struct edac_device_ctl_info *edac_ctl)
+{
+	struct arm64_pvt *pvt = edac_ctl->pvt_info;
+	int cpu;
+	call_single_data_t *csd;
+
+	get_online_cpus();
+	for_each_cpu_and(cpu, cpu_online_mask, &pvt->compat_mask) {
+		csd = per_cpu_ptr(pvt->csd_check, cpu);
+		csd->func = read_errors;
+		csd->info = edac_ctl;
+		csd->flags = 0;
+		/* Read CPU L1/L2 errors */
+		smp_call_function_single_async(cpu, csd);
+		/* Wait until flags cleared */
+		smp_cond_load_acquire(&csd->flags, !VAL);
+	}
+	put_online_cpus();
+}
+
+static int cortex_arm64_edac_probe(struct platform_device *pdev)
+{
+	int rc, cpu;
+	struct edac_device_ctl_info *edac_ctl;
+	struct device *dev = &pdev->dev;
+	struct device_node *np, *dn = pdev->dev.of_node;
+	struct of_phandle_iterator it;
+	struct arm64_pvt *pvt;
+
+	edac_ctl = edac_device_alloc_ctl_info(sizeof(*pvt), "cpu_cache",
+					      1, "L", 2, 1, NULL, 0,
+					      edac_device_alloc_index());
+	if (!edac_ctl)
+		return -ENOMEM;
+
+	pvt = edac_ctl->pvt_info;
+	pvt->csd_check = devm_alloc_percpu(dev, call_single_data_t);
+	if (!pvt->csd_check) {
+		rc = -ENOMEM;
+		goto out_dev;
+	}
+
+	of_for_each_phandle(&it, rc, dn, "cpus", NULL, 0) {
+		np = it.node;
+		cpu = of_cpu_node_to_id(np);
+		if (cpu < 0)
+			continue;
+
+		cpumask_set_cpu(cpu, &pvt->compat_mask);
+	}
+
+	edac_ctl->edac_check = cortex_arm64_edac_check;
+	edac_ctl->dev = dev;
+	edac_ctl->mod_name = dev_name(dev);
+	edac_ctl->dev_name = dev_name(dev);
+	edac_ctl->ctl_name = EDAC_MOD_STR;
+	dev_set_drvdata(dev, edac_ctl);
+
+	rc = edac_device_add_device(edac_ctl);
+	if (rc)
+		goto out_dev;
+
+	return 0;
+
+out_dev:
+	edac_device_free_ctl_info(edac_ctl);
+
+	return rc;
+}
+
+static int cortex_arm64_edac_remove(struct platform_device *pdev)
+{
+	struct edac_device_ctl_info *edac_ctl = dev_get_drvdata(&pdev->dev);
+
+	edac_device_del_device(edac_ctl->dev);
+	edac_device_free_ctl_info(edac_ctl);
+
+	return 0;
+}
+
+static const struct of_device_id cortex_arm64_edac_of_match[] = {
+	{ .compatible = "arm,cortex-a53-edac" },
+	{ .compatible = "arm,cortex-a57-edac" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, cortex_arm64_edac_of_match);
+
+static struct platform_driver cortex_arm64_edac_driver = {
+	.probe = cortex_arm64_edac_probe,
+	.remove = cortex_arm64_edac_remove,
+	.driver = {
+		.name = EDAC_MOD_STR,
+		.of_match_table = cortex_arm64_edac_of_match,
+	},
+};
+module_platform_driver(cortex_arm64_edac_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
+MODULE_DESCRIPTION("Cortex A57 and A53 L1 and L2 cache EDAC driver");