Re: [PATCH v4 16/25] nvdimm/ocxl: Implement the Read Error Log command

[Dan Williams <dan.j.williams@intel.com>]

On Tue, Mar 31, 2020 at 1:59 AM Alastair D'Silva <alastair@d-silva.org> wrote:
>
> 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
>   ("powerpc/powernv/pmem: Forward events to userspace")

So, have a look at the recent papr_scm patches to add health flags and
smart data retrieval. I'd prefer to extend existing nvdimm device
retrieval mechanisms than invent new ones.


>
> Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
> ---
>  .../userspace-api/ioctl/ioctl-number.rst      |   1 +
>  drivers/nvdimm/ocxl/main.c                    | 240 ++++++++++++++++++
>  include/uapi/nvdimm/ocxlpmem.h                |  46 ++++
>  3 files changed, 287 insertions(+)
>  create mode 100644 include/uapi/nvdimm/ocxlpmem.h
>
> diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
> index 9425377615ce..ba0ce7dca643 100644
> --- a/Documentation/userspace-api/ioctl/ioctl-number.rst
> +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
> @@ -340,6 +340,7 @@ Code  Seq#    Include File                                           Comments
>  0xC0  00-0F  linux/usb/iowarrior.h
>  0xCA  00-0F  uapi/misc/cxl.h
>  0xCA  10-2F  uapi/misc/ocxl.h
> +0xCA  30-3F  uapi/nvdimm/ocxlpmem.h                                  OpenCAPI Persistent Memory
>  0xCA  80-BF  uapi/scsi/cxlflash_ioctl.h
>  0xCB  00-1F                                                          CBM serial IEC bus in development:
>                                                                       <mailto:michael.klein@puffin.lb.shuttle.de>
> diff --git a/drivers/nvdimm/ocxl/main.c b/drivers/nvdimm/ocxl/main.c
> index 9b85fcd3f1c9..e6be0029f658 100644
> --- a/drivers/nvdimm/ocxl/main.c
> +++ b/drivers/nvdimm/ocxl/main.c
> @@ -13,6 +13,7 @@
>  #include <linux/fs.h>
>  #include <linux/mm_types.h>
>  #include <linux/memory_hotplug.h>
> +#include <uapi/nvdimm/ocxlpmem.h>
>  #include "ocxlpmem.h"
>
>  static const struct pci_device_id pci_tbl[] = {
> @@ -401,10 +402,190 @@ static int file_release(struct inode *inode, struct file *file)
>         return 0;
>  }
>
> +/**
> + * error_log_header_parse() - Parse the first 64 bits of the error log command response
> + * @ocxlpmem: the device metadata
> + * @length: out, returns the number of bytes in the response (excluding the 64 bit header)
> + */
> +static int error_log_header_parse(struct ocxlpmem *ocxlpmem, u16 *length)
> +{
> +       int rc;
> +       u64 val;
> +       u16 data_identifier;
> +       u32 data_length;
> +
> +       rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
> +                                    ocxlpmem->admin_command.data_offset,
> +                                    OCXL_LITTLE_ENDIAN, &val);
> +       if (rc)
> +               return rc;
> +
> +       data_identifier = val >> 48;
> +       data_length = val & 0xFFFF;
> +
> +       if (data_identifier != 0x454C) { // 'EL'
> +               dev_err(&ocxlpmem->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 read_error_log(struct ocxlpmem *ocxlpmem,
> +                         struct ioctl_ocxlpmem_error_log *log,
> +                         bool buf_is_user)
> +{
> +       u64 val;
> +       u16 user_buf_length;
> +       u16 buf_length;
> +       u64 *buf = (u64 *)log->buf_ptr;
> +       u16 i;
> +       int rc;
> +
> +       if (log->buf_size % 8)
> +               return -EINVAL;
> +
> +       rc = ocxlpmem_chi(ocxlpmem, &val);
> +       if (rc)
> +               return rc;
> +
> +       if (!(val & GLOBAL_MMIO_CHI_ELA))
> +               return -EAGAIN;
> +
> +       user_buf_length = log->buf_size;
> +
> +       mutex_lock(&ocxlpmem->admin_command.lock);
> +
> +       rc = admin_command_execute(ocxlpmem, ADMIN_COMMAND_ERRLOG);
> +       if (rc != STATUS_SUCCESS) {
> +               warn_status(ocxlpmem,
> +                           "Unexpected status from retrieve error log", rc);
> +               goto out;
> +       }
> +
> +       rc = error_log_header_parse(ocxlpmem, &log->buf_size);
> +       if (rc)
> +               goto out;
> +       // log->buf_size now contains the returned buffer size, not the user size
> +
> +       rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
> +                                    ocxlpmem->admin_command.data_offset + 0x08,
> +                                    OCXL_LITTLE_ENDIAN, &val);
> +       if (rc)
> +               goto out;
> +
> +       log->log_identifier = val >> 32;
> +       log->program_reference_code = val & 0xFFFFFFFF;
> +
> +       rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
> +                                    ocxlpmem->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 == OCXLPMEM_ERROR_LOG_TYPE_GENERAL) ?
> +                           (val >> 32) & 0xFFFFFF : 0;
> +       log->power_on_seconds = val & 0xFFFFFFFF;
> +
> +       rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
> +                                    ocxlpmem->admin_command.data_offset + 0x18,
> +                                    OCXL_LITTLE_ENDIAN, &log->timestamp);
> +       if (rc)
> +               goto out;
> +
> +       rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
> +                                    ocxlpmem->admin_command.data_offset + 0x20,
> +                                    OCXL_LITTLE_ENDIAN, &log->wwid[0]);
> +       if (rc)
> +               goto out;
> +
> +       rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
> +                                    ocxlpmem->admin_command.data_offset + 0x28,
> +                                    OCXL_LITTLE_ENDIAN, &log->wwid[1]);
> +       if (rc)
> +               goto out;
> +
> +       rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
> +                                    ocxlpmem->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 / (sizeof(u64)); i++) {
> +               rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
> +                                            ocxlpmem->admin_command.data_offset +
> +                                                       i * sizeof(u64),
> +                                            OCXL_HOST_ENDIAN, &val);
> +               if (rc)
> +                       goto out;
> +
> +               if (buf_is_user) {
> +                       if (copy_to_user((u64 __user *)&buf[i], &val,
> +                                        sizeof(u64))) {
> +                               rc = -EFAULT;
> +                               goto out;
> +                       }
> +               } else {
> +                       buf[i] = val;
> +               }
> +       }
> +
> +       rc = admin_response_handled(ocxlpmem);
> +       if (rc)
> +               goto out;
> +
> +out:
> +       mutex_unlock(&ocxlpmem->admin_command.lock);
> +       return rc;
> +}
> +
> +static int ioctl_error_log(struct ocxlpmem *ocxlpmem,
> +                          struct ioctl_ocxlpmem_error_log __user *uarg)
> +{
> +       struct ioctl_ocxlpmem_error_log args;
> +       int rc;
> +
> +       if (copy_from_user(&args, uarg, sizeof(args)))
> +               return -EFAULT;
> +
> +       rc = read_error_log(ocxlpmem, &args, true);
> +       if (rc)
> +               return rc;
> +
> +       if (copy_to_user(uarg, &args, sizeof(args)))
> +               return -EFAULT;
> +
> +       return 0;
> +}
> +
> +static long file_ioctl(struct file *file, unsigned int cmd, unsigned long args)
> +{
> +       struct ocxlpmem *ocxlpmem = file->private_data;
> +       int rc = -EINVAL;
> +
> +       switch (cmd) {
> +       case IOCTL_OCXLPMEM_ERROR_LOG:
> +               rc = ioctl_error_log(ocxlpmem,
> +                                    (struct ioctl_ocxlpmem_error_log __user *)args);
> +               break;
> +       }
> +       return rc;
> +}
> +
>  static const struct file_operations fops = {
>         .owner          = THIS_MODULE,
>         .open           = file_open,
>         .release        = file_release,
> +       .unlocked_ioctl = file_ioctl,
> +       .compat_ioctl   = file_ioctl,
>  };
>
>  /**
> @@ -493,6 +674,60 @@ static int read_device_metadata(struct ocxlpmem *ocxlpmem)
>         return 0;
>  }
>
> +static const char *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 dump_error_log(struct ocxlpmem *ocxlpmem)
> +{
> +       struct ioctl_ocxlpmem_error_log log;
> +       u32 buf_size;
> +       u8 *buf;
> +       int rc;
> +
> +       if (ocxlpmem->admin_command.data_size == 0)
> +               return;
> +
> +       buf_size = ocxlpmem->admin_command.data_size - 0x48;
> +       buf = kzalloc(buf_size, GFP_KERNEL);
> +       if (!buf)
> +               return;
> +
> +       log.buf_ptr = (u64)buf;
> +       log.buf_size = buf_size;
> +
> +       rc = read_error_log(ocxlpmem, &log, false);
> +       if (rc < 0)
> +               goto out;
> +
> +       dev_warn(&ocxlpmem->dev,
> +                "OCXL PMEM 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,
> +                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);
> +}
> +
>  /**
>   * probe_function0() - Set up function 0 for an OpenCAPI persistent memory device
>   * This is important as it enables templates higher than 0 across all other
> @@ -656,6 +891,11 @@ static int probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>         pci_set_drvdata(pdev, NULL);
>
>  err:
> +       if (ocxlpmem &&
> +           (ocxlpmem_chi(ocxlpmem, &chi) == 0) &&
> +           (chi & GLOBAL_MMIO_CHI_ELA))
> +               dump_error_log(ocxlpmem);
> +
>         /*
>          * Further cleanup is done in the release handler via free_ocxlpmem()
>          * This allows us to keep the character device live to handle IOCTLs to
> diff --git a/include/uapi/nvdimm/ocxlpmem.h b/include/uapi/nvdimm/ocxlpmem.h
> new file mode 100644
> index 000000000000..5d3a03ea1e08
> --- /dev/null
> +++ b/include/uapi/nvdimm/ocxlpmem.h
> @@ -0,0 +1,46 @@
> +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
> +/* Copyright 2020 IBM Corp. */
> +#ifndef _UAPI_OCXL_SCM_H
> +#define _UAPI_OCXL_SCM_H
> +
> +#include <linux/types.h>
> +#include <linux/ioctl.h>
> +
> +#define OCXLPMEM_ERROR_LOG_ACTION_RESET        (1 << (32 - 32))
> +#define OCXLPMEM_ERROR_LOG_ACTION_CHKFW        (1 << (53 - 32))
> +#define OCXLPMEM_ERROR_LOG_ACTION_REPLACE      (1 << (54 - 32))
> +#define OCXLPMEM_ERROR_LOG_ACTION_DUMP         (1 << (55 - 32))
> +
> +#define OCXLPMEM_ERROR_LOG_TYPE_GENERAL                (0x00)
> +#define OCXLPMEM_ERROR_LOG_TYPE_PREDICTIVE_FAILURE     (0x01)
> +#define OCXLPMEM_ERROR_LOG_TYPE_THERMAL_WARNING        (0x02)
> +#define OCXLPMEM_ERROR_LOG_TYPE_DATA_LOSS              (0x03)
> +#define OCXLPMEM_ERROR_LOG_TYPE_HEALTH_PERFORMANCE     (0x04)
> +
> +struct ioctl_ocxlpmem_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 */
> +       __u8  reserved0[7];
> +       __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[5];
> +       __u64 buf_ptr; /* coerced pointer to output buffer */
> +       __u64 reserved2[2];
> +};
> +
> +/* ioctl numbers */
> +#define OCXLPMEM_MAGIC 0xCA
> +/* OpenCAPI Persistent memory devices */
> +#define IOCTL_OCXLPMEM_ERROR_LOG                       _IOWR(OCXLPMEM_MAGIC, 0x30, struct ioctl_ocxlpmem_error_log)
> +
> +#endif /* _UAPI_OCXL_SCM_H */
> --
> 2.24.1
>
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