Re: [PATCH v2 2/4] edac: Add support for Amazon's Annapurna Labs L1 EDAC

Jonathan Cameron
2019-07-09T09:32:52Z

On Sun, 7 Jul 2019 14:57:36 +0300
Hanna Hawa <hhhawa@amazon.com> wrote:

> Adds support for Amazon's Annapurna Labs L1 EDAC driver to detect and
> report L1 errors.
>
> Signed-off-by: Hanna Hawa <hhhawa@amazon.com>
A quick drive by review as I was feeling curious.

Just a couple of trivial queries and observation on the fact it
might be useful to add a few devm managed functions to cut down
on edac driver boilerplate.

Thanks,

Jonathan

> ---
> MAINTAINERS | 6 ++
> drivers/edac/Kconfig | 8 +++
> drivers/edac/Makefile | 1 +
> drivers/edac/al_l1_edac.c | 154 ++++++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 169 insertions(+)
> create mode 100644 drivers/edac/al_l1_edac.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 77eae44..fd29ea6 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -743,6 +743,12 @@ F: drivers/tty/serial/altera_jtaguart.c
> F: include/linux/altera_uart.h
> F: include/linux/altera_jtaguart.h
>
> +AMAZON ANNAPURNA LABS L1 EDAC
> +M: Hanna Hawa <hhhawa@amazon.com>
> +S: Maintained
> +F: drivers/edac/al_l1_edac.c
> +F: Documentation/devicetree/bindings/edac/amazon,al-l1-edac.txt
> +
> AMAZON ANNAPURNA LABS THERMAL MMIO DRIVER
> M: Talel Shenhar <talel@amazon.com>
> S: Maintained
> diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
> index 200c04c..58b92bc 100644
> --- a/drivers/edac/Kconfig
> +++ b/drivers/edac/Kconfig
> @@ -74,6 +74,14 @@ config EDAC_GHES
>
> In doubt, say 'Y'.
>
> +config EDAC_AL_L1
> + bool "Amazon's Annapurna Labs L1 EDAC"
> + depends on ARCH_ALPINE
> + help
> + Support for L1 error detection and correction
> + for Amazon's Annapurna Labs SoCs.
> + This driver detects errors of L1 caches.
> +
> config EDAC_AMD64
> tristate "AMD64 (Opteron, Athlon64)"
> depends on AMD_NB && EDAC_DECODE_MCE
> diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile
> index 165ca65e..caa2dc9 100644
> --- a/drivers/edac/Makefile
> +++ b/drivers/edac/Makefile
> @@ -22,6 +22,7 @@ obj-$(CONFIG_EDAC_GHES) += ghes_edac.o
> edac_mce_amd-y := mce_amd.o
> obj-$(CONFIG_EDAC_DECODE_MCE) += edac_mce_amd.o
>
> +obj-$(CONFIG_EDAC_AL_L1) += al_l1_edac.o
> obj-$(CONFIG_EDAC_AMD76X) += amd76x_edac.o
> obj-$(CONFIG_EDAC_CPC925) += cpc925_edac.o
> obj-$(CONFIG_EDAC_I5000) += i5000_edac.o
> diff --git a/drivers/edac/al_l1_edac.c b/drivers/edac/al_l1_edac.c
> new file mode 100644
> index 0000000..f51a6c3
> --- /dev/null
> +++ b/drivers/edac/al_l1_edac.c
> @@ -0,0 +1,154 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
> + */
> +
> +#include <linux/bitfield.h>
> +
> +#include "edac_device.h"
> +#include "edac_module.h"
> +
> +/* Same bit assignments of CPUMERRSR_EL1 in ARM CA57/CA72 */
> +#define ARM_CA57_CPUMERRSR_EL1 sys_reg(3, 1, 15, 2, 2)
> +#define ARM_CA57_CPUMERRSR_RAM_ID GENMASK(30, 24)
> +#define ARM_CA57_L1_I_TAG_RAM 0x00
> +#define ARM_CA57_L1_I_DATA_RAM 0x01
> +#define ARM_CA57_L1_D_TAG_RAM 0x08
> +#define ARM_CA57_L1_D_DATA_RAM 0x09
> +#define ARM_CA57_L2_TLB_RAM 0x18
> +#define ARM_CA57_CPUMERRSR_VALID GENMASK(31, 31)

For a single bit it's common to use BIT(31) rather than GENMASK to make
it explicit.

> +#define ARM_CA57_CPUMERRSR_REPEAT GENMASK(39, 32)
> +#define ARM_CA57_CPUMERRSR_OTHER GENMASK(47, 40)
> +#define ARM_CA57_CPUMERRSR_FATAL GENMASK(63, 63)
> +
> +#define AL_L1_EDAC_MSG_MAX 256
> +
> +static void al_l1_edac_cpumerrsr(void *arg)
> +{
> + struct edac_device_ctl_info *edac_dev = arg;
> + int cpu, i;
> + u32 ramid, repeat, other, fatal;
> + u64 val = read_sysreg_s(ARM_CA57_CPUMERRSR_EL1);
> + char msg[AL_L1_EDAC_MSG_MAX];
> + int space, count;
> + char *p;
> +
> + if (!(FIELD_GET(ARM_CA57_CPUMERRSR_VALID, val)))
> + return;
> +
> + cpu = smp_processor_id();
> + ramid = FIELD_GET(ARM_CA57_CPUMERRSR_RAM_ID, val);
> + repeat = FIELD_GET(ARM_CA57_CPUMERRSR_REPEAT, val);
> + other = FIELD_GET(ARM_CA57_CPUMERRSR_OTHER, val);
> + fatal = FIELD_GET(ARM_CA57_CPUMERRSR_FATAL, val);
> +
> + space = sizeof(msg);
> + p = msg;
> + count = snprintf(p, space, "CPU%d L1 %serror detected", cpu,
> + (fatal) ? "Fatal " : "");
> + p += count;
> + space -= count;
> +
> + switch (ramid) {
> + case ARM_CA57_L1_I_TAG_RAM:
> + count = snprintf(p, space, " RAMID='L1-I Tag RAM'");
> + break;
> + case ARM_CA57_L1_I_DATA_RAM:
> + count = snprintf(p, space, " RAMID='L1-I Data RAM'");
> + break;
> + case ARM_CA57_L1_D_TAG_RAM:
> + count = snprintf(p, space, " RAMID='L1-D Tag RAM'");
> + break;
> + case ARM_CA57_L1_D_DATA_RAM:
> + count = snprintf(p, space, " RAMID='L1-D Data RAM'");
> + break;
> + case ARM_CA57_L2_TLB_RAM:
> + count = snprintf(p, space, " RAMID='L2 TLB RAM'");
> + break;
> + default:
> + count = snprintf(p, space, " RAMID='unknown'");
> + break;
> + }
> +
> + p += count;
> + space -= count;
> + count = snprintf(p, space,
> + " repeat=%d, other=%d (CPUMERRSR_EL1=0x%llx)",
> + repeat, other, val);
> +
> + for (i = 0; i < repeat; i++) {
> + if (fatal)
> + edac_device_handle_ue(edac_dev, 0, 0, msg);
> + else
> + edac_device_handle_ce(edac_dev, 0, 0, msg);
> + }
> +
> + write_sysreg_s(0, ARM_CA57_CPUMERRSR_EL1);
> +}
> +
> +static void al_l1_edac_check(struct edac_device_ctl_info *edac_dev)
> +{
> + on_each_cpu(al_l1_edac_cpumerrsr, edac_dev, 1);
> +}
> +
> +static int al_l1_edac_probe(struct platform_device *pdev)
> +{
> + struct edac_device_ctl_info *edac_dev;
> + struct device *dev = &pdev->dev;
> + int ret;
> +
> + edac_dev = edac_device_alloc_ctl_info(0, (char *)dev_name(dev), 1, "L",
> + 1, 1, NULL, 0,
> + edac_device_alloc_index());
> + if (IS_ERR(edac_dev))
> + return -ENOMEM;
> +
> + edac_dev->edac_check = al_l1_edac_check;
> + edac_dev->dev = dev;
> + edac_dev->mod_name = dev_name(dev);

I'd admit I'm not that familiar with edac, but seems odd that a
module name field would have the dev_name.

> + edac_dev->dev_name = dev_name(dev);
> + edac_dev->ctl_name = dev_name(dev);
> + platform_set_drvdata(pdev, edac_dev);
> +
> + ret = edac_device_add_device(edac_dev);
> + if (ret) {
> + dev_err(dev, "Failed to add L1 edac device\n");
> + goto err;
> + }
> +
> + return 0;
> +err:
> + edac_device_free_ctl_info(edac_dev);
> +
> + return ret;
> +}
> +
> +static int al_l1_edac_remove(struct platform_device *pdev)
> +{
> + struct edac_device_ctl_info *edac_dev = platform_get_drvdata(pdev);
> +
> + edac_device_del_device(edac_dev->dev);
> + edac_device_free_ctl_info(edac_dev);

More a passing observation than a suggestion for this driver, but if there was
ever a place where it looked like a couple of devm_ allocation functions would
be useful, this is it ;)

edac_dev = devm_device_alloc_ctrl_info(dev, ...)
...
devm_edac_device_add_device(dev, ...)

> +
> + return 0;
> +}
> +
> +static const struct of_device_id al_l1_edac_of_match[] = {
> + { .compatible = "amazon,al-l1-edac" },
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, al_l1_edac_of_match);
> +
> +static struct platform_driver al_l1_edac_driver = {
> + .probe = al_l1_edac_probe,
> + .remove = al_l1_edac_remove,
> + .driver = {
> + .name = "al_l1_edac",
> + .of_match_table = al_l1_edac_of_match,
> + },
> +};
> +module_platform_driver(al_l1_edac_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Hanna Hawa <hhhawa@amazon.com>");
> +MODULE_DESCRIPTION("Amazon's Annapurna Lab's L1 EDAC Driver");