Re: [PATCH v9 3/9] misc: smpro-errmon: Add Ampere's SMpro error monitor driver

From: Quan Nguyen
Date: Thu Oct 06 2022 - 03:45:02 EST




On 29/09/2022 16:53, Greg Kroah-Hartman wrote:
On Thu, Sep 29, 2022 at 04:43:15PM +0700, Quan Nguyen wrote:
This commit adds Ampere's SMpro error monitor driver for monitoring
and reporting RAS-related errors as reported by SMpro co-processor
found on Ampere's Altra processor family.

Signed-off-by: Quan Nguyen <quan@xxxxxxxxxxxxxxxxxxxxxx>
---
Changes in v9:
+ Fix ugly static struct define [Greg]
+ Remove unused defines and update documentation [Quan]
+ Add minor refactor code [Quan]
+ Fix messy goto [Greg]
+ Update SPDX licence [Greg]
+ Use ATTRIBUTE_GROUPS() [Greg]
+ Use dev_groups instead of sysfs_create_group() to avoid
racing issue with user space [Greg]
+ Refactor code to fix unnecessary initialization issue [Quan]
+ Refactor code to avoid clever encoding issue [Quan]
+ Separate error_[smpro|pmpro] to error_* and warn_* [Quan]
+ Add minor code refactor [Quan]

Changes in v8:
+ Update wording for SMPRO_ERRMON on Kconfig file [Quan]
+ Avoid uninitialized variable use [kernel test robot]
+ Switch to use sysfs_emit() [Greg]
+ Make sysfs to return single value [Greg]
+ Change errors_* sysfs to error_* [Quan]
+ Add overflow_[core|mem|pcie|other]_[ce|ue] sysfs to report
overflow status of each type of HW errors [Quan]
+ Add some minor refactor [Quan]

Changes in v7:
+ Remove regmap_acquire/release_lock(), read_i2c_block_data() [Quan]
+ Use regmap_noinc_read() instead of errmon_read_block() [Quan]
+ Validate number of errors before read [Quan]
+ Fix wrong return type of *_show() function [kernel test robot]
+ Adjust patch order to avoid dependence with smpro-mfd [Lee Jones]
+ Use pointer instead of stack memory [Quan]

Changes in v6:
+ First introduced in v6 [Quan]

drivers/misc/Kconfig | 12 +
drivers/misc/Makefile | 1 +
drivers/misc/smpro-errmon.c | 529 ++++++++++++++++++++++++++++++++++++
3 files changed, 542 insertions(+)
create mode 100644 drivers/misc/smpro-errmon.c

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 358ad56f6524..b9ceee949dab 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -176,6 +176,18 @@ config SGI_XP
this feature will allow for direct communication between SSIs
based on a network adapter and DMA messaging.
+config SMPRO_ERRMON
+ tristate "Ampere Computing SMPro error monitor driver"
+ depends on MFD_SMPRO || COMPILE_TEST
+ help
+ Say Y here to get support for the SMpro error monitor function
+ provided by Ampere Computing's Altra and Altra Max SoCs. Upon
+ loading, the driver creates sysfs files which can be use to gather
+ multiple HW error data reported via read and write system calls.
+
+ To compile this driver as a module, say M here. The driver will be
+ called smpro-errmon.
+
config CS5535_MFGPT
tristate "CS5535/CS5536 Geode Multi-Function General Purpose Timer (MFGPT) support"
depends on MFD_CS5535
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index ac9b3e757ba1..bbe24d4511a3 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_ENCLOSURE_SERVICES) += enclosure.o
obj-$(CONFIG_KGDB_TESTS) += kgdbts.o
obj-$(CONFIG_SGI_XP) += sgi-xp/
obj-$(CONFIG_SGI_GRU) += sgi-gru/
+obj-$(CONFIG_SMPRO_ERRMON) += smpro-errmon.o
obj-$(CONFIG_CS5535_MFGPT) += cs5535-mfgpt.o
obj-$(CONFIG_GEHC_ACHC) += gehc-achc.o
obj-$(CONFIG_HP_ILO) += hpilo.o
diff --git a/drivers/misc/smpro-errmon.c b/drivers/misc/smpro-errmon.c
new file mode 100644
index 000000000000..d1431d419aa4
--- /dev/null
+++ b/drivers/misc/smpro-errmon.c
@@ -0,0 +1,529 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Ampere Computing SoC's SMpro Error Monitoring Driver
+ *
+ * Copyright (c) 2022, Ampere Computing LLC
+ *
+ */
+
+#include <linux/i2c.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+/* GPI RAS Error Registers */
+#define GPI_RAS_ERR 0x7E
+
+/* Core and L2C Error Registers */
+#define CORE_CE_ERR_CNT 0x80
+#define CORE_CE_ERR_LEN 0x81
+#define CORE_CE_ERR_DATA 0x82
+#define CORE_UE_ERR_CNT 0x83
+#define CORE_UE_ERR_LEN 0x84
+#define CORE_UE_ERR_DATA 0x85
+
+/* Memory Error Registers */
+#define MEM_CE_ERR_CNT 0x90
+#define MEM_CE_ERR_LEN 0x91
+#define MEM_CE_ERR_DATA 0x92
+#define MEM_UE_ERR_CNT 0x93
+#define MEM_UE_ERR_LEN 0x94
+#define MEM_UE_ERR_DATA 0x95
+
+/* RAS Error/Warning Registers */
+#define ERR_SMPRO_TYPE 0xA0
+#define ERR_PMPRO_TYPE 0xA1
+#define ERR_SMPRO_INFO_LO 0xA2
+#define ERR_SMPRO_INFO_HI 0xA3
+#define ERR_SMPRO_DATA_LO 0xA4
+#define ERR_SMPRO_DATA_HI 0xA5
+#define WARN_SMPRO_INFO_LO 0xAA
+#define WARN_SMPRO_INFO_HI 0xAB
+#define ERR_PMPRO_INFO_LO 0xA6
+#define ERR_PMPRO_INFO_HI 0xA7
+#define ERR_PMPRO_DATA_LO 0xA8
+#define ERR_PMPRO_DATA_HI 0xA9
+#define WARN_PMPRO_INFO_LO 0xAC
+#define WARN_PMPRO_INFO_HI 0xAD
+
+/* PCIE Error Registers */
+#define PCIE_CE_ERR_CNT 0xC0
+#define PCIE_CE_ERR_LEN 0xC1
+#define PCIE_CE_ERR_DATA 0xC2
+#define PCIE_UE_ERR_CNT 0xC3
+#define PCIE_UE_ERR_LEN 0xC4
+#define PCIE_UE_ERR_DATA 0xC5
+
+/* Other Error Registers */
+#define OTHER_CE_ERR_CNT 0xD0
+#define OTHER_CE_ERR_LEN 0xD1
+#define OTHER_CE_ERR_DATA 0xD2
+#define OTHER_UE_ERR_CNT 0xD8
+#define OTHER_UE_ERR_LEN 0xD9
+#define OTHER_UE_ERR_DATA 0xDA
+
+/* Event Data Registers */
+#define VRD_WARN_FAULT_EVENT_DATA 0x78
+#define VRD_HOT_EVENT_DATA 0x79
+#define DIMM_HOT_EVENT_DATA 0x7A
+
+#define MAX_READ_BLOCK_LENGTH 48
+
+#define RAS_SMPRO_ERR 0
+#define RAS_PMPRO_ERR 1
+
+enum RAS_48BYTES_ERR_TYPES {
+ CORE_CE_ERR,
+ CORE_UE_ERR,
+ MEM_CE_ERR,
+ MEM_UE_ERR,
+ PCIE_CE_ERR,
+ PCIE_UE_ERR,
+ OTHER_CE_ERR,
+ OTHER_UE_ERR,
+ NUM_48BYTES_ERR_TYPE,
+};
+
+struct smpro_error_hdr {
+ u8 count; /* Number of the RAS errors */
+ u8 len; /* Number of data bytes */
+ u8 data; /* Start of 48-byte data */
+ u8 max_cnt; /* Max num of errors */
+};
+
+/*
+ * Included Address of registers to get Count, Length of data and Data
+ * of the 48 bytes error data
+ */
+static struct smpro_error_hdr smpro_error_table[] = {
+ [CORE_CE_ERR] = {
+ .count = CORE_CE_ERR_CNT,
+ .len = CORE_CE_ERR_LEN,
+ .data = CORE_CE_ERR_DATA,
+ .max_cnt = 32
+ },
+ [CORE_UE_ERR] = {
+ .count = CORE_UE_ERR_CNT,
+ .len = CORE_UE_ERR_LEN,
+ .data = CORE_UE_ERR_DATA,
+ .max_cnt = 32
+ },
+ [MEM_CE_ERR] = {
+ .count = MEM_CE_ERR_CNT,
+ .len = MEM_CE_ERR_LEN,
+ .data = MEM_CE_ERR_DATA,
+ .max_cnt = 16
+ },
+ [MEM_UE_ERR] = {
+ .count = MEM_UE_ERR_CNT,
+ .len = MEM_UE_ERR_LEN,
+ .data = MEM_UE_ERR_DATA,
+ .max_cnt = 16
+ },
+ [PCIE_CE_ERR] = {
+ .count = PCIE_CE_ERR_CNT,
+ .len = PCIE_CE_ERR_LEN,
+ .data = PCIE_CE_ERR_DATA,
+ .max_cnt = 96
+ },
+ [PCIE_UE_ERR] = {
+ .count = PCIE_UE_ERR_CNT,
+ .len = PCIE_UE_ERR_LEN,
+ .data = PCIE_UE_ERR_DATA,
+ .max_cnt = 96
+ },
+ [OTHER_CE_ERR] = {
+ .count = OTHER_CE_ERR_CNT,
+ .len = OTHER_CE_ERR_LEN,
+ .data = OTHER_CE_ERR_DATA,
+ .max_cnt = 8
+ },
+ [OTHER_UE_ERR] = {
+ .count = OTHER_UE_ERR_CNT,
+ .len = OTHER_UE_ERR_LEN,
+ .data = OTHER_UE_ERR_DATA,
+ .max_cnt = 8
+ },
+};
+
+/*
+ * List of SCP registers which are used to get
+ * one type of RAS Internal errors.
+ */
+struct smpro_int_error_hdr {
+ u8 type;
+ u8 info_l;
+ u8 info_h;
+ u8 data_l;
+ u8 data_h;
+ u8 warn_l;
+ u8 warn_h;
+};
+
+static struct smpro_int_error_hdr list_smpro_int_error_hdr[] = {
+ [RAS_SMPRO_ERR] = {
+ .type = ERR_SMPRO_TYPE,
+ .info_l = ERR_SMPRO_INFO_LO,
+ .info_h = ERR_SMPRO_INFO_HI,
+ .data_l = ERR_SMPRO_DATA_LO,
+ .data_h = ERR_SMPRO_DATA_HI,
+ .warn_l = WARN_SMPRO_INFO_LO,
+ .warn_h = WARN_SMPRO_INFO_HI,
+ },
+ [RAS_PMPRO_ERR] = {
+ .type = ERR_PMPRO_TYPE,
+ .info_l = ERR_PMPRO_INFO_LO,
+ .info_h = ERR_PMPRO_INFO_HI,
+ .data_l = ERR_PMPRO_DATA_LO,
+ .data_h = ERR_PMPRO_DATA_HI,
+ .warn_l = WARN_PMPRO_INFO_LO,
+ .warn_h = WARN_PMPRO_INFO_HI,
+ },
+};
+
+struct smpro_errmon {
+ struct regmap *regmap;
+};
+
+enum EVENT_TYPES {
+ VRD_WARN_FAULT_EVENT,
+ VRD_HOT_EVENT,
+ DIMM_HOT_EVENT,
+ NUM_EVENTS_TYPE,
+};
+
+/* Included Address of event source and data registers */
+static u8 smpro_event_table[NUM_EVENTS_TYPE] = {
+ VRD_WARN_FAULT_EVENT_DATA,
+ VRD_HOT_EVENT_DATA,
+ DIMM_HOT_EVENT_DATA,
+};
+
+static ssize_t smpro_event_data_read(struct device *dev,
+ struct device_attribute *da, char *buf,
+ int channel)
+{
+ struct smpro_errmon *errmon = dev_get_drvdata(dev);
+ s32 event_data;
+ int ret;
+
+ ret = regmap_read(errmon->regmap, smpro_event_table[channel], &event_data);
+ if (ret)
+ return ret;
+ /* Clear event after read */
+ if (event_data != 0)
+ regmap_write(errmon->regmap, smpro_event_table[channel], event_data);
+
+ return sysfs_emit(buf, "%04x\n", event_data);
+}
+
+static ssize_t smpro_overflow_data_read(struct device *dev, struct device_attribute *da,
+ char *buf, int channel)
+{
+ struct smpro_errmon *errmon = dev_get_drvdata(dev);
+ struct smpro_error_hdr *err_info;
+ s32 err_count;
+ int ret;
+
+ err_info = &smpro_error_table[channel];
+
+ ret = regmap_read(errmon->regmap, err_info->count, &err_count);
+ if (ret)
+ return ret;
+
+ /* Bit 8 indicates the overflow status */
+ return sysfs_emit(buf, "%d\n", (err_count & BIT(8)) ? 1 : 0);
+}

Where is the Documentation/ABI/ entry for this field?

It is documented under the entry for the "/sys/bus/platform/devices/smpro-errmon.*/overflow_[core|mem|pcie|other]_[ce|ue]" in the [9/9] patch.

Please put that in the same commit so that it is easier to validate that
you really did document everything properly.


I'll follow this suggestion in next version.

Thank your for the reviews,
- Quan