Re: [PATCH v2 16/27] nvdimm/ocxl: Implement the Read Error Log command

Alastair D'Silva
2019-12-05T03:42:28Z

On Tue, 2019-12-03 at 14:46 +1100, Alastair D'Silva wrote:
> From: Alastair D'Silva <alastair@d-silva.org>
>
> The read error log command extracts information from the controller's
> internal error log.
>
> This patch exposes this information in 2 ways:
> - During probe, if an error occurs & a log is available, print it to
> the
> console
> - After probe, make the error log available to userspace via an
> IOCTL.
> Userspace is notified of pending error logs in a later patch
> ("nvdimm/ocxl: Forward events to userspace")
>
> Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
> ---
> drivers/nvdimm/ocxl/scm.c | 270
> +++++++++++++++++++++++++++++
> drivers/nvdimm/ocxl/scm_internal.h | 1 +
> include/uapi/nvdimm/ocxl-scm.h | 46 +++++
> 3 files changed, 317 insertions(+)
> create mode 100644 include/uapi/nvdimm/ocxl-scm.h
>
> diff --git a/drivers/nvdimm/ocxl/scm.c b/drivers/nvdimm/ocxl/scm.c
> index c313a473a28e..0bbe1a14291e 100644
> --- a/drivers/nvdimm/ocxl/scm.c
> +++ b/drivers/nvdimm/ocxl/scm.c
> @@ -495,10 +495,220 @@ static int scm_file_release(struct inode
> *inode, struct file *file)
> return 0;
> }
>
> +/**
> + * scm_error_log_header_parse() - Parse the first 64 bits of the
> error log command response
> + * @scm_data: the SCM metadata
> + * @length: out, returns the number of bytes in the response
> (excluding the 64 bit header)
> + */
> +static int scm_error_log_header_parse(struct scm_data *scm_data, u16
> *length)
> +{
> + int rc;
> + u64 val;
> +
> + u16 data_identifier;
> + u32 data_length;
> +
> + rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> + scm_data-
> >admin_command.data_offset,
> + OCXL_LITTLE_ENDIAN, &val);
> + if (rc)
> + return rc;
> +
> + data_identifier = val >> 48;
> + data_length = val & 0xFFFF;
> +
> + if (data_identifier != 0x454C) {
> + dev_err(&scm_data->dev,
> + "Bad data identifier for error log data,
> expected 'EL', got '%2s' (%#x), data_length=%u\n",
> + (char *)&data_identifier,
> + (unsigned int)data_identifier, data_length);
> + return -EINVAL;
> + }
> +
> + *length = data_length;
> + return 0;
> +}
> +
> +static int scm_error_log_offset_0x08(struct scm_data *scm_data,
> + u32 *log_identifier, u32
> *program_ref_code)
> +{
> + int rc;
> + u64 val;
> +
> + rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> + scm_data-
> >admin_command.data_offset + 0x08,
> + OCXL_LITTLE_ENDIAN, &val);
> + if (rc)
> + return rc;
> +
> + *log_identifier = val >> 32;
> + *program_ref_code = val & 0xFFFFFFFF;
> +
> + return 0;
> +}
> +
> +static int scm_read_error_log(struct scm_data *scm_data,
> + struct scm_ioctl_error_log *log, bool
> buf_is_user)
> +{
> + u64 val;
> + u16 user_buf_length;
> + u16 buf_length;
> + u16 i;
> + int rc;
> +
> + if (log->buf_size % 8)
> + return -EINVAL;
> +
> + rc = scm_chi(scm_data, &val);
> + if (rc)
> + goto out;
> +
> + if (!(val & GLOBAL_MMIO_CHI_ELA))
> + return -EAGAIN;
> +
> + user_buf_length = log->buf_size;
> +
> + mutex_lock(&scm_data->admin_command.lock);
> +
> + rc = scm_admin_command_request(scm_data, ADMIN_COMMAND_ERRLOG);
> + if (rc)
> + goto out;
> +
> + rc = scm_admin_command_execute(scm_data);
> + if (rc)
> + goto out;
> +
> + rc = scm_admin_command_complete_timeout(scm_data,
> ADMIN_COMMAND_ERRLOG);
> + if (rc < 0) {
> + dev_warn(&scm_data->dev, "Read error log timed out\n");
> + goto out;
> + }
> +
> + rc = scm_admin_response(scm_data);
> + if (rc < 0)
> + goto out;
> + if (rc != STATUS_SUCCESS) {
> + scm_warn_status(scm_data, "Unexpected status from
> retrieve error log", rc);
> + goto out;
> + }
> +
> +
> + rc = scm_error_log_header_parse(scm_data, &log->buf_size);
> + if (rc)
> + goto out;
> + // log->buf_size now contains the scm buffer size, not the user
> size
> +
> + rc = scm_error_log_offset_0x08(scm_data, &log->log_identifier,
> + &log->program_reference_code);
> + if (rc)
> + goto out;
> +
> + rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> + scm_data-
> >admin_command.data_offset + 0x10,
> + OCXL_LITTLE_ENDIAN, &val);
> + if (rc)
> + goto out;
> +
> + log->error_log_type = val >> 56;
> + log->action_flags = (log->error_log_type ==
> SCM_ERROR_LOG_TYPE_GENERAL) ?
> + (val >> 32) & 0xFFFFFF : 0;
> + log->power_on_seconds = val & 0xFFFFFFFF;
> +
> + rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> + scm_data-
> >admin_command.data_offset + 0x18,
> + OCXL_LITTLE_ENDIAN, &log-
> >timestamp);
> + if (rc)
> + goto out;
> +
> + rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> + scm_data-
> >admin_command.data_offset + 0x20,
> + OCXL_HOST_ENDIAN, &log->wwid[0]);
> + if (rc)
> + goto out;
> +
> + rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> + scm_data-
> >admin_command.data_offset + 0x28,
> + OCXL_HOST_ENDIAN, &log->wwid[1]);
> + if (rc)
> + goto out;
> +
> + rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> + scm_data-
> >admin_command.data_offset + 0x30,
> + OCXL_HOST_ENDIAN, (u64 *)log-
> >fw_revision);
> + if (rc)
> + goto out;
> + log->fw_revision[8] = '\0';
> +
> + buf_length = (user_buf_length < log->buf_size) ?
> + user_buf_length : log->buf_size;
> + for (i = 0; i < buf_length + 0x48; i += 8) {
> + u64 val;
> +
> + rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> + scm_data-
> >admin_command.data_offset + i,
> + OCXL_HOST_ENDIAN, &val);
> + if (rc)
> + goto out;
> +
> + if (buf_is_user) {
> + if (copy_to_user(&log->buf[i], &val,
> sizeof(u64))) {
> + rc = -EFAULT;
> + goto out;
> + }
> + } else
> + log->buf[i] = val;
> + }
> +
> + rc = scm_admin_response_handled(scm_data);
> + if (rc)
> + goto out;
> +
> +out:
> + mutex_unlock(&scm_data->admin_command.lock);
> + return rc;
> +
> +}
> +
> +static int scm_ioctl_error_log(struct scm_data *scm_data,
> + struct scm_ioctl_error_log __user *uarg)
> +{
> + struct scm_ioctl_error_log args;
> + int rc;
> +
> + if (copy_from_user(&args, uarg, sizeof(args)))
> + return -EFAULT;
> +
> + rc = scm_read_error_log(scm_data, &args, true);
> + if (rc)
> + return rc;
> +
> + if (copy_to_user(uarg, &args, sizeof(args)))
> + return -EFAULT;
> +
> + return 0;
> +}
> +
> +static long scm_file_ioctl(struct file *file, unsigned int cmd,
> + unsigned long args)
> +{
> + struct scm_data *scm_data = file->private_data;
> + int rc = -EINVAL;
> +
> + switch (cmd) {
> + case SCM_IOCTL_ERROR_LOG:
> + rc = scm_ioctl_error_log(scm_data,
> + (struct scm_ioctl_error_log
> __user *)args);
> + break;
> + }
> + return rc;
> +}
> +
> static const struct file_operations scm_fops = {
> .owner = THIS_MODULE,
> .open = scm_file_open,
> .release = scm_file_release,
> + .unlocked_ioctl = scm_file_ioctl,
> + .compat_ioctl = scm_file_ioctl,
> };
>
> /**
> @@ -575,6 +785,60 @@ static int read_device_metadata(struct scm_data
> *scm_data)
> return 0;
> }
>
> +static const char *scm_decode_error_log_type(u8 error_log_type)
> +{
> + switch (error_log_type) {
> + case 0x00:
> + return "general";
> + case 0x01:
> + return "predictive failure";
> + case 0x02:
> + return "thermal warning";
> + case 0x03:
> + return "data loss";
> + case 0x04:
> + return "health & performance";
> + default:
> + return "unknown";
> + }
> +}
> +
> +static void scm_dump_error_log(struct scm_data *scm_data)
> +{
> + struct scm_ioctl_error_log log;
> + u32 buf_size;
> + u8 *buf;
> + int rc;
> +
> + if (scm_data->admin_command.data_size == 0)
> + return;
> +
> + buf_size = scm_data->admin_command.data_size - 0x48;
> + buf = kzalloc(buf_size, GFP_KERNEL);
> + if (!buf)
> + return;
> +
> + log.buf = buf;
> + log.buf_size = buf_size;
> +
> + rc = scm_read_error_log(scm_data, &log, false);
> + if (rc < 0)
> + goto out;
> +
> + dev_warn(&scm_data->dev,
> + "SCM Error log: WWID=0x%016llx%016llx LID=0x%x PRC=%x
> type=0x%x %s, Uptime=%u seconds timestamp=0x%llx\n",
> + log.wwid[0], log.wwid[1],
> + log.log_identifier, log.program_reference_code,
> + log.error_log_type,
> + scm_decode_error_log_type(log.error_log_type),
> + log.power_on_seconds, log.timestamp);
> + print_hex_dump(KERN_WARNING, "buf", DUMP_PREFIX_OFFSET, 16, 1,
> buf,
> + log.buf_size, false);
> +
> +out:
> + kfree(buf);
> +}
> +
> /**
> * scm_probe_function_0 - Set up function 0 for an OpenCAPI Storage
> Class Memory device
> * This is important as it enables templates higher than 0 across
> all other functions,
> @@ -617,6 +881,7 @@ static int scm_probe(struct pci_dev *pdev, const
> struct pci_device_id *ent)
> struct scm_data *scm_data = NULL;
> int elapsed;
> u16 timeout;
> + u64 chi;
>
> if (PCI_FUNC(pdev->devfn) == 0)
> return scm_probe_function_0(pdev);
> @@ -707,6 +972,11 @@ static int scm_probe(struct pci_dev *pdev, const
> struct pci_device_id *ent)
> return 0;
>
> err:
> + if (scm_data &&
> + (scm_chi(scm_data, &chi) == 0) &&
> + (chi & GLOBAL_MMIO_CHI_ELA))
> + scm_dump_error_log(scm_data);
> +
> /*
> * Further cleanup is done in the release handler via
> free_scm()
> * This allows us to keep the character device live to handle
> IOCTLs to
> diff --git a/drivers/nvdimm/ocxl/scm_internal.h
> b/drivers/nvdimm/ocxl/scm_internal.h
> index 57491dbee1a4..9bf8fcf30ea6 100644
> --- a/drivers/nvdimm/ocxl/scm_internal.h
> +++ b/drivers/nvdimm/ocxl/scm_internal.h
> @@ -5,6 +5,7 @@
> #include <linux/cdev.h>
> #include <misc/ocxl.h>
> #include <linux/libnvdimm.h>
> +#include <uapi/linux/ocxl-scm.h>

This should be uapi/nvdimm/ocxl-scm.h

> #include <linux/mm.h>
>
> #define SCM_DEFAULT_TIMEOUT 100
> diff --git a/include/uapi/nvdimm/ocxl-scm.h
> b/include/uapi/nvdimm/ocxl-scm.h
> new file mode 100644
> index 000000000000..b34dd1ba06ff
> --- /dev/null
> +++ b/include/uapi/nvdimm/ocxl-scm.h
> @@ -0,0 +1,46 @@
> +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
> +/* Copyright 2017 IBM Corp. */
> +#ifndef _UAPI_OCXL_SCM_H
> +#define _UAPI_OCXL_SCM_H
> +
> +#include <linux/types.h>
> +#include <linux/ioctl.h>
> +
> +#define SCM_ERROR_LOG_ACTION_RESET (1 << (32-32))
> +#define SCM_ERROR_LOG_ACTION_CHKFW (1 << (53-32))
> +#define SCM_ERROR_LOG_ACTION_REPLACE (1 << (54-32))
> +#define SCM_ERROR_LOG_ACTION_DUMP (1 << (55-32))
> +
> +#define SCM_ERROR_LOG_TYPE_GENERAL (0x00)
> +#define SCM_ERROR_LOG_TYPE_PREDICTIVE_FAILURE (0x01)
> +#define SCM_ERROR_LOG_TYPE_THERMAL_WARNING (0x02)
> +#define SCM_ERROR_LOG_TYPE_DATA_LOSS (0x03)
> +#define SCM_ERROR_LOG_TYPE_HEALTH_PERFORMANCE (0x04)
> +
> +struct scm_ioctl_error_log {
> + __u32 log_identifier; // out
> + __u32 program_reference_code; // out
> + __u32 action_flags; //out, recommended course of action
> + __u32 power_on_seconds; // out, Number of seconds the
> controller has been on when the error occurred
> + __u64 timestamp; // out, relative time since the current IPL
> + __u64 wwid[2]; // out, the NAA formatted WWID associated with
> the controller
> + char fw_revision[8+1]; // out, firmware revision as null
> terminated text
> + __u16 buf_size; /* in/out, buffer size provided/required.
> + * If required is greater than provided, the
> buffer
> + * will be truncated to the amount provided. If
> its
> + * less, then only the required bytes will be
> populated.
> + * If it is 0, then there are no more error log
> entries.
> + */
> + __u8 error_log_type;
> + __u8 reserved1;
> + __u32 reserved2;
> + __u64 reserved3[2];
> + __u8 *buf; // pointer to output buffer
> +};
> +
> +/* ioctl numbers */
> +#define SCM_MAGIC 0x5C
> +/* SCM devices */
> +#define SCM_IOCTL_ERROR_LOG _IOWR(SCM_MAGIC, 0x01, struct
> scm_ioctl_error_log)
> +
> +#endif /* _UAPI_OCXL_SCM_H */
--
Alastair D'Silva
Open Source Developer
Linux Technology Centre, IBM Australia
mob: 0423 762 819