Re: [PATCH v2 3/4] drivers: edac: Add EDAC driver support for QCOM SoCs
From: vnkgutta
Date: Fri Aug 24 2018 - 17:05:27 EST
On 2018-08-24 13:18, Evan Green wrote:
On Fri, Aug 24, 2018 at 11:32 AM <vnkgutta@xxxxxxxxxxxxxx> wrote:
On 2018-08-23 16:04, Evan Green wrote:
> On Fri, Aug 17, 2018 at 5:08 PM Venkata Narendra Kumar Gutta
> <vnkgutta@xxxxxxxxxxxxxx> wrote:
>>
>> From: Channagoud Kadabi <ckadabi@xxxxxxxxxxxxxx>
>>
>> Add error reporting driver for Single Bit Errors (SBEs) and Double Bit
>> Errors (DBEs). As of now, this driver supports erp for Last Level
>> Cache
>> Controller (LLCC). This driver takes care of dumping registers and
>> adding
>> config options to enable and disable panic when the errors happen in
>> cache.
>>
>> Signed-off-by: Channagoud Kadabi <ckadabi@xxxxxxxxxxxxxx>
>> Signed-off-by: Venkata Narendra Kumar Gutta <vnkgutta@xxxxxxxxxxxxxx>
>> Co-developed-by: Venkata Narendra Kumar Gutta
>> <vnkgutta@xxxxxxxxxxxxxx>
>> ---
>> MAINTAINERS | 8 +
>> drivers/edac/Kconfig | 28 +++
>> drivers/edac/Makefile | 1 +
>> drivers/edac/qcom_edac.c | 446
>> +++++++++++++++++++++++++++++++++++++
>> include/linux/soc/qcom/llcc-qcom.h | 25 +++
>> 5 files changed, 508 insertions(+)
>> create mode 100644 drivers/edac/qcom_edac.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 0a23427..0bff713 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -5227,6 +5227,14 @@ L: linux-edac@xxxxxxxxxxxxxxx
>> S: Maintained
>> F: drivers/edac/ti_edac.c
>>
>> +EDAC-QUALCOMM
>> +M: Channagoud Kadabi <ckadabi@xxxxxxxxxxxxxx>
>> +M: Venkata Narendra Kumar Gutta <vnkgutta@xxxxxxxxxxxxxx>
>> +L: linux-arm-msm@xxxxxxxxxxxxxxx
>> +L: linux-edac@xxxxxxxxxxxxxxx
>> +S: Maintained
>> +F: drivers/edac/qcom_edac.c
>> +
>> EDIROL UA-101/UA-1000 DRIVER
>> M: Clemens Ladisch <clemens@xxxxxxxxxx>
>> L: alsa-devel@xxxxxxxxxxxxxxxx (moderated for non-subscribers)
>> diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
>> index 57304b2..da8f150 100644
>> --- a/drivers/edac/Kconfig
>> +++ b/drivers/edac/Kconfig
>> @@ -460,4 +460,32 @@ config EDAC_TI
>> Support for error detection and correction on the
>> TI SoCs.
>>
>> +config EDAC_QCOM
>> + tristate "QCOM EDAC Controller"
>> + depends on EDAC
>> + help
>> + Support for error detection and correction on the
>> + QCOM SoCs.
>> +
>> +config EDAC_QCOM_LLCC
>> + tristate "QCOM EDAC Controller for LLCC Cache"
>> + depends on EDAC_QCOM && QCOM_LLCC
>> + help
>> + Support for error detection and correction on the
>> + QCOM LLCC cache. Report errors caught by LLCC ECC
>> + mechanism.
>> +
>> + For debugging issues having to do with stability and overall
>> system
>> + health, you should probably say 'Y' here.
>> +
>> +config EDAC_QCOM_LLCC_PANIC_ON_UE
>> + bool "Panic on uncorrectable errors - qcom llcc"
>> + depends on EDAC_QCOM_LLCC
>> + help
>> + Forcibly cause a kernel panic if an uncorrectable error (UE)
>> is
>> + detected. This can reduce debugging times on hardware which
>> may be
>> + operating at voltages or frequencies outside normal
>> specification.
>> +
>> + For production builds, you should probably say 'N' here.
>> +
>> endif # EDAC
>> diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile
>> index 02b43a7..716096d 100644
>> --- a/drivers/edac/Makefile
>> +++ b/drivers/edac/Makefile
>> @@ -77,3 +77,4 @@ obj-$(CONFIG_EDAC_ALTERA) +=
>> altera_edac.o
>> obj-$(CONFIG_EDAC_SYNOPSYS) += synopsys_edac.o
>> obj-$(CONFIG_EDAC_XGENE) += xgene_edac.o
>> obj-$(CONFIG_EDAC_TI) += ti_edac.o
>> +obj-$(CONFIG_EDAC_QCOM) += qcom_edac.o
>> diff --git a/drivers/edac/qcom_edac.c b/drivers/edac/qcom_edac.c
>> new file mode 100644
>> index 0000000..9a8c670
>> --- /dev/null
>> +++ b/drivers/edac/qcom_edac.c
>> @@ -0,0 +1,446 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Copyright (c) 2018, The Linux Foundation. All rights reserved.
>> + */
>> +
>> +#include <linux/edac.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/kernel.h>
>> +#include <linux/of_device.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regmap.h>
>> +#include <linux/smp.h>
>> +#include <linux/soc/qcom/llcc-qcom.h>
>> +
>> +#include "edac_mc.h"
>> +#include "edac_device.h"
>> +
>> +#ifdef CONFIG_EDAC_QCOM_LLCC_PANIC_ON_UE
>> +#define LLCC_ERP_PANIC_ON_UE 1
>> +#else
>> +#define LLCC_ERP_PANIC_ON_UE 0
>> +#endif
>> +
>> +#define EDAC_LLCC "qcom_llcc"
>> +
>> +#define TRP_SYN_REG_CNT 6
>> +
>> +#define DRP_SYN_REG_CNT 8
>> +
>> +#define LLCC_COMMON_STATUS0 0x0003000C
>> +#define LLCC_LB_CNT_MASK GENMASK(31, 28)
>> +#define LLCC_LB_CNT_SHIFT 28
>> +
>> +/* single & Double Bit syndrome register offsets */
>
> Strange capitalization going on here.
I'll fix this.
>
>> +#define TRP_ECC_SB_ERR_SYN0 0x0002304C
>> +#define TRP_ECC_DB_ERR_SYN0 0x00020370
>> +#define DRP_ECC_SB_ERR_SYN0 0x0004204C
>> +#define DRP_ECC_DB_ERR_SYN0 0x00042070
>
> I think the convention is to use lowercase hex everywhere.
I didn't get you. Do you mean, the Macros should be in lower case or
the
comments?
I mean 0x0002304C should be 0x0002304c.
Oh, I see. I'll update it, Thanks.
>
>> +
>> +/* Error register offsets */
>> +#define TRP_ECC_ERROR_STATUS1 0x00020348
>> +#define TRP_ECC_ERROR_STATUS0 0x00020344
>> +#define DRP_ECC_ERROR_STATUS1 0x00042048
>> +#define DRP_ECC_ERROR_STATUS0 0x00042044
>> +
>> +/* TRP, DRP interrupt register offsets */
>> +#define DRP_INTERRUPT_STATUS 0x00041000
>> +#define TRP_INTERRUPT_0_STATUS 0x00020480
>> +#define DRP_INTERRUPT_CLEAR 0x00041008
>> +#define DRP_ECC_ERROR_CNTR_CLEAR 0x00040004
>> +#define TRP_INTERRUPT_0_CLEAR 0x00020484
>> +#define TRP_ECC_ERROR_CNTR_CLEAR 0x00020440
>> +
>> +/* Mask and shift macros */
>> +#define ECC_DB_ERR_COUNT_MASK GENMASK(4, 0)
>> +#define ECC_DB_ERR_WAYS_MASK GENMASK(31, 16)
>> +#define ECC_DB_ERR_WAYS_SHIFT BIT(4)
>> +
>> +#define ECC_SB_ERR_COUNT_MASK GENMASK(23, 16)
>> +#define ECC_SB_ERR_COUNT_SHIFT BIT(4)
>> +#define ECC_SB_ERR_WAYS_MASK GENMASK(15, 0)
>> +
>> +#define SB_ECC_ERROR BIT(0)
>> +#define DB_ECC_ERROR BIT(1)
>> +
>> +#define DRP_TRP_INT_CLEAR GENMASK(1, 0)
>> +#define DRP_TRP_CNT_CLEAR GENMASK(1, 0)
>> +
>> +/* Config registers offsets*/
>> +#define DRP_ECC_ERROR_CFG 0x00040000
>> +
>> +/* TRP, DRP interrupt register offsets */
>> +#define CMN_INTERRUPT_0_ENABLE 0x0003001C
>> +#define CMN_INTERRUPT_2_ENABLE 0x0003003C
>> +#define TRP_INTERRUPT_0_ENABLE 0x00020488
>> +#define DRP_INTERRUPT_ENABLE 0x0004100C
>> +
>> +#define SB_ERROR_THRESHOLD 0x1
>> +#define SB_ERROR_THRESHOLD_SHIFT 24
>> +#define SB_DB_TRP_INTERRUPT_ENABLE 0x3
>> +#define TRP0_INTERRUPT_ENABLE 0x1
>> +#define DRP0_INTERRUPT_ENABLE BIT(6)
>> +#define SB_DB_DRP_INTERRUPT_ENABLE 0x3
>> +
>> +enum {
>> + LLCC_DRAM_CE = 0,
>> + LLCC_DRAM_UE,
>> + LLCC_TRAM_CE,
>> + LLCC_TRAM_UE,
>> + LLCC_ERR_TYPE_MAX = LLCC_TRAM_UE + 1,
>
> This is a nit, or perhaps personal preference, but I prefer to not
> have initializers for sentinel values, since it's one more thing
> someone could forget to update when adding new values.
I'll get rid of this, I was using this one to allocate the memory for
llcc_driv_data->edac_reg, (struct llcc_edac_reg_data).
But the suggestion was to initialize that one statically.
Sounds good.
>
>> +};
>> +
>> +static int qcom_llcc_core_setup(struct regmap *llcc_bcast_regmap)
>> +{
>> + u32 sb_err_threshold;
>> + int ret;
>> +
>> + /* Enable TRP in instance 2 of common interrupt enable
>> register */
>
> Can we get a comment explaining what's so special about instance 2?
> Instances 1 and 3 get no love?
I'll try to elaborate on this.
>
>> + ret = regmap_update_bits(llcc_bcast_regmap,
>> CMN_INTERRUPT_2_ENABLE,
>> + TRP0_INTERRUPT_ENABLE,
>> + TRP0_INTERRUPT_ENABLE);
>> + if (ret)
>> + return ret;
>> +
>> + /* Enable ECC interrupts on Tag Ram */
>> + ret = regmap_update_bits(llcc_bcast_regmap,
>> TRP_INTERRUPT_0_ENABLE,
>> + SB_DB_TRP_INTERRUPT_ENABLE,
>> + SB_DB_TRP_INTERRUPT_ENABLE);
>> + if (ret)
>> + return ret;
>> +
>> + /* Enable SB error for Data RAM */
>> + sb_err_threshold = (SB_ERROR_THRESHOLD <<
>> SB_ERROR_THRESHOLD_SHIFT);
>> + ret = regmap_write(llcc_bcast_regmap, DRP_ECC_ERROR_CFG,
>> + sb_err_threshold);
>> + if (ret)
>> + return ret;
>> +
>> + /* Enable DRP in instance 2 of common interrupt enable
>> register */
>> + ret = regmap_update_bits(llcc_bcast_regmap,
>> CMN_INTERRUPT_2_ENABLE,
>> + DRP0_INTERRUPT_ENABLE,
>> + DRP0_INTERRUPT_ENABLE);
>> + if (ret)
>> + return ret;
>> +
>> + /* Enable ECC interrupts on Data Ram */
>> + ret = regmap_write(llcc_bcast_regmap, DRP_INTERRUPT_ENABLE,
>> + SB_DB_DRP_INTERRUPT_ENABLE);
>> + return ret;
>> +}
>> +
>> +/* Clear the error interrupt and counter registers */
>> +static int
>> +qcom_llcc_clear_errors_status(int err_type, struct llcc_drv_data
>> *drv)
>
> Another nit: errors_status is kind of weird. Maybe
> qcom_llcc_clear_errors or qcom_llcc_clear_error_status?
I'll update the name.
>
>> +{
>> + int ret = 0;
>> +
>> + switch (err_type) {
>> + case LLCC_DRAM_CE:
>> + case LLCC_DRAM_UE:
>> + /* Clear the interrupt */
>> + ret = regmap_write(drv->bcast_regmap,
>> DRP_INTERRUPT_CLEAR,
>> + DRP_TRP_INT_CLEAR);
>> + if (ret)
>> + return ret;
>> +
>> + /* Clear the counters */
>> + ret = regmap_write(drv->bcast_regmap,
>> DRP_ECC_ERROR_CNTR_CLEAR,
>> + DRP_TRP_CNT_CLEAR);
>> + if (ret)
>> + return ret;
>> + break;
>> + case LLCC_TRAM_CE:
>> + case LLCC_TRAM_UE:
>> + ret = regmap_write(drv->bcast_regmap,
>> TRP_INTERRUPT_0_CLEAR,
>> + DRP_TRP_INT_CLEAR);
>> + if (ret)
>> + return ret;
>> +
>> + ret = regmap_write(drv->bcast_regmap,
>> TRP_ECC_ERROR_CNTR_CLEAR,
>> + DRP_TRP_CNT_CLEAR);
>> + if (ret)
>> + return ret;
>> + break;
>
> A default case that errors or complains or both would be nice.
Ok, I had this thought too, but we never run into that scenario,
that's we don't ever call this function with any other types,
Had it been an API it makes sense to have a default case.
The internal functions require them too! I don't know!!
What do you think?
As we say, if it's good to have it, I'll add it.
I personally like the default case, I find it to be defensive against
someone adding code later who passes the wrong value or type down.
Others might disagree. It's up to you.
It makes sense to have a defensive code against someone adding the code
later,
I'll add it.