diff mbox series

[v6,6/9] misc: smpro-errmon: Add Ampere's SMpro error monitor driver

Message ID 20211224041352.29405-7-quan@os.amperecomputing.com
State New
Headers show
Series Add Ampere's Altra SMPro MFD and its child drivers | expand

Commit Message

Quan Nguyen Dec. 24, 2021, 4:13 a.m. UTC
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@os.amperecomputing.com>
---
Change in v6:
  + First introduced in v6 [Quan]

 drivers/mfd/smpro-mfd.c     |   1 +
 drivers/misc/Kconfig        |   7 +
 drivers/misc/Makefile       |   1 +
 drivers/misc/smpro-errmon.c | 571 ++++++++++++++++++++++++++++++++++++
 4 files changed, 580 insertions(+)
 create mode 100644 drivers/misc/smpro-errmon.c

Comments

Greg KH Dec. 24, 2021, 8:32 a.m. UTC | #1
On Fri, Dec 24, 2021 at 11:13:49AM +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@os.amperecomputing.com>
> ---
> Change in v6:
>   + First introduced in v6 [Quan]
> 
>  drivers/mfd/smpro-mfd.c     |   1 +
>  drivers/misc/Kconfig        |   7 +
>  drivers/misc/Makefile       |   1 +
>  drivers/misc/smpro-errmon.c | 571 ++++++++++++++++++++++++++++++++++++
>  4 files changed, 580 insertions(+)
>  create mode 100644 drivers/misc/smpro-errmon.c

You need Documentation/ABI/ updates when you add sysfs files.  Please do
that for your next version of this patch.

Also remember that sysfs is only "one value per file", this driver seems
to violate that in huge ways and is not ok.

thanks,

greg k-h
Mark Brown Dec. 24, 2021, 1:28 p.m. UTC | #2
On Fri, Dec 24, 2021 at 11:13:49AM +0700, Quan Nguyen wrote:

> +static int read_i2c_block_data(struct i2c_client *client, u16 address, u16 length, u8 *data)
> +{
> +	unsigned char outbuf[MAX_READ_BLOCK_LENGTH];
> +	unsigned char inbuf[2];
> +	struct i2c_msg msgs[2];
> +	ssize_t ret;
> +
> +	inbuf[0] = (address & 0xff);
> +	inbuf[1] = length;
> +
> +	msgs[0].addr = client->addr;
> +	msgs[0].flags = client->flags & I2C_M_TEN;
> +	msgs[0].len = 2;
> +	msgs[0].buf = inbuf;
> +
> +	msgs[1].addr = client->addr;
> +	msgs[1].flags = (client->flags  & I2C_M_TEN) | I2C_M_RD;
> +	msgs[1].len = length;
> +	msgs[1].buf = outbuf;
> +
> +	ret = i2c_transfer(client->adapter, msgs, NUM_I2C_MESSAGES);
> +	if (ret < 0)

regmap already supports bulk data access so it's not clear why we
would open code this.  Given that this is a single I2C transfer
it's also unclear why we'd need to export the regmap lock - a
single I2C transfer is atomic at the bus level so the regmap lock
isn't providing any additional concurrency protection.
Lee Jones Dec. 29, 2021, 10:16 a.m. UTC | #3
On Fri, 24 Dec 2021, 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@os.amperecomputing.com>
> ---
> Change in v6:
>   + First introduced in v6 [Quan]
> 
>  drivers/mfd/smpro-mfd.c     |   1 +

Separate patch please.

>  drivers/misc/Kconfig        |   7 +
>  drivers/misc/Makefile       |   1 +
>  drivers/misc/smpro-errmon.c | 571 ++++++++++++++++++++++++++++++++++++
>  4 files changed, 580 insertions(+)
>  create mode 100644 drivers/misc/smpro-errmon.c
Quan Nguyen March 7, 2022, 8:30 a.m. UTC | #4
On 24/12/2021 20:28, Mark Brown wrote:
> On Fri, Dec 24, 2021 at 11:13:49AM +0700, Quan Nguyen wrote:
> 
>> +static int read_i2c_block_data(struct i2c_client *client, u16 address, u16 length, u8 *data)
>> +{
>> +	unsigned char outbuf[MAX_READ_BLOCK_LENGTH];
>> +	unsigned char inbuf[2];
>> +	struct i2c_msg msgs[2];
>> +	ssize_t ret;
>> +
>> +	inbuf[0] = (address & 0xff);
>> +	inbuf[1] = length;
>> +
>> +	msgs[0].addr = client->addr;
>> +	msgs[0].flags = client->flags & I2C_M_TEN;
>> +	msgs[0].len = 2;
>> +	msgs[0].buf = inbuf;
>> +
>> +	msgs[1].addr = client->addr;
>> +	msgs[1].flags = (client->flags  & I2C_M_TEN) | I2C_M_RD;
>> +	msgs[1].len = length;
>> +	msgs[1].buf = outbuf;
>> +
>> +	ret = i2c_transfer(client->adapter, msgs, NUM_I2C_MESSAGES);
>> +	if (ret < 0)
> 
> regmap already supports bulk data access so it's not clear why we
> would open code this.  Given that this is a single I2C transfer
> it's also unclear why we'd need to export the regmap lock - a
> single I2C transfer is atomic at the bus level so the regmap lock
> isn't providing any additional concurrency protection.

Thanks a lot for the review, Mark.
Even though the single i2c transfer is atomic at the bus level, but my 
concerns is that the transfer may be interlaced with some other 
transaction from the regmap which was guarded by regmap's lock. And so 
making these accesses atomic in regmap level should be done as well. 
That is why I need the regmap's lock export for user driver.

But your comment made re-think about the code, and I think we can handle 
multiple types of transfer by using remap_bus->read/write(). The 
read_i2c_block_data() is now replaced by regmap_noinc_read() and hence, 
remove the use of regmap's lock. These changes will be included in my 
next version.

Thanks,
- Quan
Quan Nguyen March 7, 2022, 8:31 a.m. UTC | #5
Dear Lee Jones,

This mail is to reply your comment in https://lkml.org/lkml/2021/12/29/120

Thanks for the review,
- Quan

On 24/12/2021 11:13, 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@os.amperecomputing.com>
> ---
> Change in v6:
>    + First introduced in v6 [Quan]
> 
>   drivers/mfd/smpro-mfd.c     |   1 +

[Lee Jones] Separate patch please

Will separate this smpro-mfd.c in single patch only in my next version

>   drivers/misc/Kconfig        |   7 +
>   drivers/misc/Makefile       |   1 +
>   drivers/misc/smpro-errmon.c | 571 ++++++++++++++++++++++++++++++++++++
>   4 files changed, 580 insertions(+)
>   create mode 100644 drivers/misc/smpro-errmon.c
>
Quan Nguyen March 7, 2022, 8:32 a.m. UTC | #6
On 24/12/2021 15:32, Greg Kroah-Hartman wrote:
> On Fri, Dec 24, 2021 at 11:13:49AM +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@os.amperecomputing.com>
>> ---
>> Change in v6:
>>    + First introduced in v6 [Quan]
>>
>>   drivers/mfd/smpro-mfd.c     |   1 +
>>   drivers/misc/Kconfig        |   7 +
>>   drivers/misc/Makefile       |   1 +
>>   drivers/misc/smpro-errmon.c | 571 ++++++++++++++++++++++++++++++++++++
>>   4 files changed, 580 insertions(+)
>>   create mode 100644 drivers/misc/smpro-errmon.c
> 
> You need Documentation/ABI/ updates when you add sysfs files.  Please do
> that for your next version of this patch.
> 

Thanks greg for the review,
Will update Documentation/ABI/testing/sysfs-* file in next version.

> Also remember that sysfs is only "one value per file", this driver seems
> to violate that in huge ways and is not ok.
> 

These sysfs's does not return "multi value per file" but a single record 
of data, one example is to return the 48-byte ARM RAS Vendor specific 
error record.

Thanks
- Quan
diff mbox series

Patch

diff --git a/drivers/mfd/smpro-mfd.c b/drivers/mfd/smpro-mfd.c
index 132d4e2dde12..a7cd64bf9eaa 100644
--- a/drivers/mfd/smpro-mfd.c
+++ b/drivers/mfd/smpro-mfd.c
@@ -27,6 +27,7 @@  static const struct regmap_config simple_word_regmap_config = {
 
 static const struct mfd_cell smpro_devs[] = {
 	MFD_CELL_NAME("smpro-hwmon"),
+	MFD_CELL_NAME("smpro-errmon"),
 };
 
 static int smpro_mfd_probe(struct i2c_client *i2c)
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 0f5a49fc7c9e..0cbd8a2561a7 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -176,6 +176,13 @@  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
+	  If you say yes here you get support for error monitor function
+	  provides by Ampere Computing's SoC with SMpro processor.
+
 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 a086197af544..8ec9961b941b 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..d694ebb06977
--- /dev/null
+++ b/drivers/misc/smpro-errmon.c
@@ -0,0 +1,571 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Ampere Computing SoC's SMpro Error Monitoring Driver
+ *
+ * Copyright (c) 2021, 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 Source Registers */
+#define EVENT_SRC1		0x62
+#define EVENT_SRC2		0x63
+
+/* Event Data Registers */
+#define VRD_WARN_FAULT_EVENT_DATA	0x78
+#define VRD_HOT_EVENT_DATA		0x79
+#define DIMM_HOT_EVENT_DATA		0x7A
+#define DIMM_2X_REFRESH_EVENT_DATA	0x96
+
+#define MAX_READ_BLOCK_LENGTH	48
+#define NUM_I2C_MESSAGES	2
+#define MAX_READ_ERROR		35
+#define MAX_MSG_LEN		128
+
+#define RAS_SMPRO_ERRS		0
+#define RAS_PMPRO_ERRS		1
+
+enum RAS_48BYTES_ERR_TYPES {
+	CORE_CE_ERRS,
+	CORE_UE_ERRS,
+	MEM_CE_ERRS,
+	MEM_UE_ERRS,
+	PCIE_CE_ERRS,
+	PCIE_UE_ERRS,
+	OTHER_CE_ERRS,
+	OTHER_UE_ERRS,
+	NUM_48BYTES_ERR_TYPE,
+};
+
+struct smpro_error_hdr {
+	u8 err_count;	/* Number of the RAS errors */
+	u8 err_len;	/* Number of data bytes */
+	u8 err_data;	/* Start of 48-byte data */
+};
+
+/*
+ * Included Address of registers to get Count, Length of data and Data
+ * of the 48 bytes error data
+ */
+struct smpro_error_hdr smpro_error_table[NUM_48BYTES_ERR_TYPE] = {
+	{CORE_CE_ERR_CNT, CORE_CE_ERR_LEN, CORE_CE_ERR_DATA},
+	{CORE_UE_ERR_CNT, CORE_UE_ERR_LEN, CORE_UE_ERR_DATA},
+	{MEM_CE_ERR_CNT, MEM_CE_ERR_LEN, MEM_CE_ERR_DATA},
+	{MEM_UE_ERR_CNT, MEM_UE_ERR_LEN, MEM_UE_ERR_DATA},
+	{PCIE_CE_ERR_CNT, PCIE_CE_ERR_LEN, PCIE_CE_ERR_DATA},
+	{PCIE_UE_ERR_CNT, PCIE_UE_ERR_LEN, PCIE_UE_ERR_DATA},
+	{OTHER_CE_ERR_CNT, OTHER_CE_ERR_LEN, OTHER_CE_ERR_DATA},
+	{OTHER_UE_ERR_CNT, OTHER_UE_ERR_LEN, OTHER_UE_ERR_DATA},
+};
+
+/*
+ * List of SCP registers which are used to get
+ * one type of RAS Internal errors.
+ */
+struct smpro_int_error_hdr {
+	u8 err_type;
+	u8 err_info_low;
+	u8 err_info_high;
+	u8 err_data_high;
+	u8 err_data_low;
+	u8 warn_info_low;
+	u8 warn_info_high;
+};
+
+struct smpro_int_error_hdr list_smpro_int_error_hdr[2] = {
+	{
+	 ERR_SMPRO_TYPE,
+	 ERR_SMPRO_INFO_LO, ERR_SMPRO_INFO_HI,
+	 ERR_SMPRO_DATA_LO, ERR_SMPRO_DATA_HI,
+	 WARN_SMPRO_INFO_LO, WARN_SMPRO_INFO_HI
+	},
+	{
+	 ERR_PMPRO_TYPE,
+	 ERR_PMPRO_INFO_LO, ERR_PMPRO_INFO_HI,
+	 ERR_PMPRO_DATA_LO, ERR_PMPRO_DATA_HI,
+	 WARN_PMPRO_INFO_LO, WARN_PMPRO_INFO_HI
+	},
+};
+
+struct smpro_errmon {
+	struct regmap *regmap;
+};
+
+enum EVENT_TYPES {
+	VRD_WARN_FAULT_EVENTS,
+	VRD_HOT_EVENTS,
+	DIMM_HOT_EVENTS,
+	NUM_EVENTS_TYPE,
+};
+
+struct smpro_event_hdr {
+	u8 event_src;	/* Source register of event type */
+	u8 event_data;	/* Data register of event type */
+};
+
+/* Included Address of event source and data registers */
+struct smpro_event_hdr smpro_event_table[NUM_EVENTS_TYPE] = {
+	{EVENT_SRC1, VRD_WARN_FAULT_EVENT_DATA},
+	{EVENT_SRC1, VRD_HOT_EVENT_DATA},
+	{EVENT_SRC2, DIMM_HOT_EVENT_DATA}
+};
+
+static int read_i2c_block_data(struct i2c_client *client, u16 address, u16 length, u8 *data)
+{
+	unsigned char outbuf[MAX_READ_BLOCK_LENGTH];
+	unsigned char inbuf[2];
+	struct i2c_msg msgs[2];
+	ssize_t ret;
+
+	inbuf[0] = (address & 0xff);
+	inbuf[1] = length;
+
+	msgs[0].addr = client->addr;
+	msgs[0].flags = client->flags & I2C_M_TEN;
+	msgs[0].len = 2;
+	msgs[0].buf = inbuf;
+
+	msgs[1].addr = client->addr;
+	msgs[1].flags = (client->flags  & I2C_M_TEN) | I2C_M_RD;
+	msgs[1].len = length;
+	msgs[1].buf = outbuf;
+
+	ret = i2c_transfer(client->adapter, msgs, NUM_I2C_MESSAGES);
+	if (ret < 0)
+		return ret;
+
+	if (ret != NUM_I2C_MESSAGES)
+		return -EIO;
+
+	memcpy(data, outbuf, length);
+
+	return length;
+}
+
+static int errmon_read_block(struct regmap *map, u16 address, u16 length, u8 *data)
+{
+	struct i2c_client *client = to_i2c_client(regmap_get_device(map));
+	int ret;
+
+	regmap_acquire_lock(map);
+
+	ret = read_i2c_block_data(client, address, length, data);
+
+	regmap_release_lock(map);
+
+	return ret;
+}
+
+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);
+	unsigned char msg[MAX_MSG_LEN] = {'\0'};
+	struct smpro_event_hdr event_info;
+	s32 event_data = 0;
+	int ret;
+
+	*buf = 0;
+	if (channel >= NUM_EVENTS_TYPE)
+		goto done;
+
+	event_info = smpro_event_table[channel];
+	ret = regmap_read(errmon->regmap, event_info.event_data, &event_data);
+	if (ret)
+		goto done;
+
+	ret = scnprintf(msg, MAX_MSG_LEN, "%02x %04x\n", channel, event_data);
+	strncat(buf, msg, ret);
+done:
+	return strlen(buf);
+}
+
+static ssize_t smpro_error_data_read(struct device *dev, struct device_attribute *da,
+				     char *buf, int channel)
+{
+	struct smpro_errmon *errmon = dev_get_drvdata(dev);
+	unsigned char err_data[MAX_READ_BLOCK_LENGTH];
+	unsigned char msg[MAX_MSG_LEN] = {'\0'};
+	struct smpro_error_hdr err_info;
+	s32 err_count = 1, err_length = 0;
+	u8 i = 0;
+	int len;
+	int ret;
+
+	*buf = 0;
+	if (channel >= NUM_48BYTES_ERR_TYPE)
+		goto done;
+
+	err_info = smpro_error_table[channel];
+
+	ret = regmap_read(errmon->regmap, err_info.err_count, &err_count);
+	if (ret || err_count <= 0)
+		goto done;
+
+	/* Bit 8 indentifies the overflow status of one error type */
+	if (err_count & BIT(8)) {
+		len = scnprintf(msg, MAX_MSG_LEN,
+				"%02x %02x %04x %08x %016llx %016llx %016llx %016llx %016llx\n",
+				0xFF, 0xFF, 0, 0, 0LL, 0LL, 0LL, 0LL, 0LL);
+		strncat(buf, msg, len);
+	}
+
+	/* Error count is the low byte */
+	err_count = err_count & 0xff;
+
+	if (err_count > MAX_READ_ERROR)
+		err_count = MAX_READ_ERROR;
+
+	for (i = 0; i < err_count; i++) {
+		ret = regmap_read(errmon->regmap, err_info.err_len, &err_length);
+		if (ret || err_length <= 0)
+			break;
+
+		if (err_length > MAX_READ_BLOCK_LENGTH)
+			err_length = MAX_READ_BLOCK_LENGTH;
+
+		ret = errmon_read_block(errmon->regmap, err_info.err_data, err_length, err_data);
+		if (ret < 0)
+			break;
+		/*
+		 * The output of Core/Memory/PCIe/Others UE/CE errors follows below format:
+		 * <Error Type>  <Error SubType>  <Instance>  <Error Status> \
+		 * <Error Address>  <Error Misc 0> <Error Misc 1> <Error Misc2> <Error Misc 3>
+		 * Where:
+		 *  + Error Type: The hardwares cause the errors. (1 byte)
+		 *  + SubType: Sub type of error in the specified hardware error. (1 byte)
+		 *  + Instance: Combination of the socket, channel,
+		 *    slot cause the error. (2 bytes)
+		 *  + Error Status: Encode of error status. (4 bytes)
+		 *  + Error Address: The address in device causes the errors. (8 bytes)
+		 *  + Error Misc 0/1/2/3: Addition info about the errors. (8 bytes for each)
+		 * Reference Altra SOC BMC Interface specification.
+		 */
+		len = scnprintf(msg, MAX_MSG_LEN,
+				"%02x %02x %04x %08x %016llx %016llx %016llx %016llx %016llx\n",
+				err_data[0], err_data[1], *(u16 *)&err_data[2],
+				*(u32 *)&err_data[4], *(u64 *)&err_data[8],
+				*(u64 *)&err_data[16], *(u64 *)&err_data[24],
+				*(u64 *)&err_data[32], *(u64 *)&err_data[40]);
+
+		/* go to next error */
+		ret = regmap_write(errmon->regmap, err_info.err_count, 0x100);
+		if (ret)
+			break;
+
+		/* add error message to buffer */
+		strncat(buf, msg, len);
+	}
+done:
+	return strlen(buf);
+}
+
+static s32 smpro_internal_err_get_info(struct regmap *regmap, u8 addr, u8 addr1, u8 addr2, u8 addr3,
+				       u8 subtype, char *buf)
+{
+	unsigned int ret_hi = 0, ret_lo = 0, data_lo = 0, data_hi = 0;
+	int ret;
+
+	ret = regmap_read(regmap, addr, &ret_lo);
+	if (ret)
+		return ret;
+
+	ret = regmap_read(regmap, addr1, &ret_hi);
+	if (ret)
+		return ret;
+
+	if (addr2 != 0xff) {
+		ret = regmap_read(regmap, addr2, &data_lo);
+		if (ret)
+			return ret;
+		ret = regmap_read(regmap, addr3, &data_hi);
+		if (ret)
+			return ret;
+	}
+	/*
+	 * Output format:
+	 * <errType> <image> <dir> <Location> <errorCode> <data>
+	 * Where:
+	 *   + errType: SCP Error Type (3 bits)
+	 *      1: Warning
+	 *      2: Error
+	 *      4: Error with data
+	 *   + image: SCP Image Code (8 bits)
+	 *   + dir: Direction (1 bit)
+	 *      0: Enter
+	 *      1: Exit
+	 *   + location: SCP Module Location Code (8 bits)
+	 *   + errorCode: SCP Error Code (16 bits)
+	 *   + data : Extensive data (32 bits)
+	 *      All bits are 0 when errType is warning or error.
+	 */
+	return scnprintf(buf, MAX_MSG_LEN, "%01x %02x %01x %02x %04x %04x%04x\n",
+			 subtype, (ret_hi & 0xf000) >> 12, (ret_hi & 0x0800) >> 11,
+			 ret_hi & 0xff, ret_lo, data_hi, data_lo);
+}
+
+static ssize_t smpro_internal_err_read(struct device *dev, struct device_attribute *da,
+				       char *buf, int channel)
+{
+	struct smpro_errmon *errmon = dev_get_drvdata(dev);
+	struct smpro_int_error_hdr err_info;
+	unsigned char msg[MAX_MSG_LEN] = {'\0'};
+	unsigned int err_type;
+	unsigned int value;
+	int ret = 0;
+
+	*buf = 0;
+	/* read error status */
+	ret = regmap_read(errmon->regmap, GPI_RAS_ERR, &value);
+	if (ret)
+		goto done;
+
+	if (!((channel == RAS_SMPRO_ERRS && (value & BIT(0))) ||
+	      (channel == RAS_PMPRO_ERRS && (value & BIT(1)))))
+		goto done;
+
+	err_info = list_smpro_int_error_hdr[channel];
+	ret = regmap_read(errmon->regmap, err_info.err_type, &err_type);
+	if (ret)
+		goto done;
+
+	/* Warning type */
+	if (err_type & BIT(0)) {
+		ret = smpro_internal_err_get_info(errmon->regmap, err_info.warn_info_low,
+						  err_info.warn_info_high, 0xff, 0xff, 1, msg);
+		if (ret < 0)
+			goto done;
+
+		strncat(buf, msg, ret);
+	}
+
+	/* Error with data type */
+	if (err_type & BIT(2)) {
+		ret = smpro_internal_err_get_info(errmon->regmap, err_info.err_info_low,
+						  err_info.err_info_high, err_info.err_data_low,
+						  err_info.err_data_high, 4, msg);
+		if (ret < 0)
+			goto done;
+
+		strncat(buf, msg, ret);
+	}
+	/* Error type */
+	else if (err_type & BIT(1)) {
+		ret = smpro_internal_err_get_info(errmon->regmap, err_info.err_info_low,
+						  err_info.err_info_high, 0xff, 0xff, 2, msg);
+		if (ret < 0)
+			goto done;
+
+		strncat(buf, msg, ret);
+	}
+
+	/* clear the read errors */
+	regmap_write(errmon->regmap, err_info.err_type, err_type);
+
+done:
+	return strlen(buf);
+}
+
+static int errors_core_ce_show(struct device *dev, struct device_attribute *da, char *buf)
+{
+	return smpro_error_data_read(dev, da, buf, CORE_CE_ERRS);
+}
+static DEVICE_ATTR_RO(errors_core_ce);
+
+static int errors_core_ue_show(struct device *dev, struct device_attribute *da, char *buf)
+{
+	return smpro_error_data_read(dev, da, buf, CORE_UE_ERRS);
+}
+static DEVICE_ATTR_RO(errors_core_ue);
+
+static int errors_mem_ce_show(struct device *dev, struct device_attribute *da, char *buf)
+{
+	return smpro_error_data_read(dev, da, buf, MEM_CE_ERRS);
+}
+static DEVICE_ATTR_RO(errors_mem_ce);
+
+static int errors_mem_ue_show(struct device *dev, struct device_attribute *da, char *buf)
+{
+	return smpro_error_data_read(dev, da, buf, MEM_UE_ERRS);
+}
+static DEVICE_ATTR_RO(errors_mem_ue);
+
+static int errors_pcie_ce_show(struct device *dev, struct device_attribute *da, char *buf)
+{
+	return smpro_error_data_read(dev, da, buf, PCIE_CE_ERRS);
+}
+static DEVICE_ATTR_RO(errors_pcie_ce);
+
+static int errors_pcie_ue_show(struct device *dev, struct device_attribute *da, char *buf)
+{
+	return smpro_error_data_read(dev, da, buf, PCIE_UE_ERRS);
+}
+static DEVICE_ATTR_RO(errors_pcie_ue);
+
+static int errors_other_ce_show(struct device *dev, struct device_attribute *da, char *buf)
+{
+	return smpro_error_data_read(dev, da, buf, OTHER_CE_ERRS);
+}
+static DEVICE_ATTR_RO(errors_other_ce);
+
+static int errors_other_ue_show(struct device *dev, struct device_attribute *da, char *buf)
+{
+	return smpro_error_data_read(dev, da, buf, OTHER_UE_ERRS);
+}
+static DEVICE_ATTR_RO(errors_other_ue);
+
+static int errors_smpro_show(struct device *dev, struct device_attribute *da, char *buf)
+{
+	return smpro_internal_err_read(dev, da, buf, RAS_SMPRO_ERRS);
+}
+static DEVICE_ATTR_RO(errors_smpro);
+
+static int errors_pmpro_show(struct device *dev, struct device_attribute *da, char *buf)
+{
+	return smpro_internal_err_read(dev, da, buf, RAS_PMPRO_ERRS);
+}
+static DEVICE_ATTR_RO(errors_pmpro);
+
+static int event_vrd_warn_fault_show(struct device *dev, struct device_attribute *da, char *buf)
+{
+	return smpro_event_data_read(dev, da, buf, VRD_WARN_FAULT_EVENTS);
+}
+static DEVICE_ATTR_RO(event_vrd_warn_fault);
+
+static int event_vrd_hot_show(struct device *dev, struct device_attribute *da, char *buf)
+{
+	return smpro_event_data_read(dev, da, buf, VRD_HOT_EVENTS);
+}
+static DEVICE_ATTR_RO(event_vrd_hot);
+
+static int event_dimm_hot_show(struct device *dev, struct device_attribute *da, char *buf)
+{
+	return smpro_event_data_read(dev, da, buf, DIMM_HOT_EVENTS);
+}
+static DEVICE_ATTR_RO(event_dimm_hot);
+
+static struct attribute *smpro_errmon_attrs[] = {
+	&dev_attr_errors_core_ce.attr,
+	&dev_attr_errors_core_ue.attr,
+	&dev_attr_errors_mem_ce.attr,
+	&dev_attr_errors_mem_ue.attr,
+	&dev_attr_errors_pcie_ce.attr,
+	&dev_attr_errors_pcie_ue.attr,
+	&dev_attr_errors_other_ce.attr,
+	&dev_attr_errors_other_ue.attr,
+	&dev_attr_errors_smpro.attr,
+	&dev_attr_errors_pmpro.attr,
+	&dev_attr_event_vrd_warn_fault.attr,
+	&dev_attr_event_vrd_hot.attr,
+	&dev_attr_event_dimm_hot.attr,
+	NULL
+};
+
+static const struct attribute_group smpro_errmon_attr_group = {
+	.attrs = smpro_errmon_attrs
+};
+
+static int smpro_errmon_probe(struct platform_device *pdev)
+{
+	struct smpro_errmon *errmon;
+	int ret;
+
+	errmon = devm_kzalloc(&pdev->dev, sizeof(struct smpro_errmon), GFP_KERNEL);
+	if (!errmon)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, errmon);
+
+	errmon->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	if (!errmon->regmap)
+		return -ENODEV;
+
+	ret = sysfs_create_group(&pdev->dev.kobj, &smpro_errmon_attr_group);
+	if (ret)
+		dev_err(&pdev->dev, "SMPro errmon sysfs registration failed\n");
+
+	return 0;
+}
+
+static int smpro_errmon_remove(struct platform_device *pdev)
+{
+	sysfs_remove_group(&pdev->dev.kobj, &smpro_errmon_attr_group);
+	pr_info("SMPro errmon sysfs entries removed");
+
+	return 0;
+}
+
+static struct platform_driver smpro_errmon_driver = {
+	.probe          = smpro_errmon_probe,
+	.remove         = smpro_errmon_remove,
+	.driver = {
+		.name   = "smpro-errmon",
+	},
+};
+
+module_platform_driver(smpro_errmon_driver);
+
+MODULE_AUTHOR("Tung Nguyen <tung.nguyen@amperecomputing.com>");
+MODULE_AUTHOR("Thinh Pham <thinh.pham@amperecomputing.com>");
+MODULE_AUTHOR("Hoang Nguyen <hnguyen@amperecomputing.com>");
+MODULE_AUTHOR("Thu Nguyen <thu@os.amperecomputing.com>");
+MODULE_AUTHOR("Quan Nguyen <quan@os.amperecomputing.com>");
+MODULE_DESCRIPTION("Ampere Altra SMpro driver");
+MODULE_LICENSE("GPL");