[PATCH v2 17/27] nvdimm/ocxl: Add controller dump IOCTLs

Alastair D'Silva
2019-12-03T03:48:41Z

From: Alastair D'Silva <alastair@d-silva.org>

This patch adds IOCTLs to allow userspace to request & fetch dumps
of the internal controller state.

This is useful during debugging or when a fatal error on the controller
has occurred.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
---
drivers/nvdimm/ocxl/scm.c | 132 +++++++++++++++++++++++++++++++++
include/uapi/nvdimm/ocxl-scm.h | 15 ++++
2 files changed, 147 insertions(+)

diff --git a/drivers/nvdimm/ocxl/scm.c b/drivers/nvdimm/ocxl/scm.c
index 0bbe1a14291e..a520f209d626 100644
--- a/drivers/nvdimm/ocxl/scm.c
+++ b/drivers/nvdimm/ocxl/scm.c
@@ -688,6 +688,124 @@ static int scm_ioctl_error_log(struct scm_data *scm_data,
return 0;
}

+static int scm_ioctl_controller_dump_data(struct scm_data *scm_data,
+ struct scm_ioctl_controller_dump_data __user *uarg)
+{
+ struct scm_ioctl_controller_dump_data args;
+ u16 i;
+ u64 val;
+ int rc;
+
+ if (copy_from_user(&args, uarg, sizeof(args)))
+ return -EFAULT;
+
+ if (args.buf_size % 8)
+ return -EINVAL;
+
+ if (args.buf_size > scm_data->admin_command.data_size)
+ return -EINVAL;
+
+ mutex_lock(&scm_data->admin_command.lock);
+
+ rc = scm_admin_command_request(scm_data, ADMIN_COMMAND_CONTROLLER_DUMP);
+ if (rc)
+ goto out;
+
+ val = ((u64)args.offset) << 32;
+ val |= args.buf_size;
+ rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
+ scm_data->admin_command.request_offset + 0x08,
+ OCXL_LITTLE_ENDIAN, val);
+ 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_CONTROLLER_DUMP);
+ if (rc < 0) {
+ dev_warn(&scm_data->dev, "Controller dump 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;
+ }
+
+ for (i = 0; i < args.buf_size; 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 (copy_to_user(&args.buf[i], &val, sizeof(u64))) {
+ rc = -EFAULT;
+ goto out;
+ }
+ }
+
+ if (copy_to_user(uarg, &args, sizeof(args))) {
+ rc = -EFAULT;
+ goto out;
+ }
+
+ rc = scm_admin_response_handled(scm_data);
+ if (rc)
+ goto out;
+
+out:
+ mutex_unlock(&scm_data->admin_command.lock);
+ return rc;
+}
+
+int scm_request_controller_dump(struct scm_data *scm_data)
+{
+ int rc;
+ u64 busy = 1;
+
+ rc = ocxl_global_mmio_set64(scm_data->ocxl_afu, GLOBAL_MMIO_CHIC,
+ OCXL_LITTLE_ENDIAN,
+ GLOBAL_MMIO_CHI_CDA);
+
+
+ rc = ocxl_global_mmio_set64(scm_data->ocxl_afu, GLOBAL_MMIO_HCI,
+ OCXL_LITTLE_ENDIAN,
+ GLOBAL_MMIO_HCI_CONTROLLER_DUMP);
+ if (rc)
+ return rc;
+
+ while (busy) {
+ rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+ GLOBAL_MMIO_HCI,
+ OCXL_LITTLE_ENDIAN, &busy);
+ if (rc)
+ return rc;
+
+ busy &= GLOBAL_MMIO_HCI_CONTROLLER_DUMP;
+ cond_resched();
+ }
+
+ return 0;
+}
+
+static int scm_ioctl_controller_dump_complete(struct scm_data *scm_data)
+{
+ return ocxl_global_mmio_set64(scm_data->ocxl_afu, GLOBAL_MMIO_HCI,
+ OCXL_LITTLE_ENDIAN,
+ GLOBAL_MMIO_HCI_CONTROLLER_DUMP_COLLECTED);
+}
+
static long scm_file_ioctl(struct file *file, unsigned int cmd,
unsigned long args)
{
@@ -699,7 +817,21 @@ static long scm_file_ioctl(struct file *file, unsigned int cmd,
rc = scm_ioctl_error_log(scm_data,
(struct scm_ioctl_error_log __user *)args);
break;
+
+ case SCM_IOCTL_CONTROLLER_DUMP:
+ rc = scm_request_controller_dump(scm_data);
+ break;
+
+ case SCM_IOCTL_CONTROLLER_DUMP_DATA:
+ rc = scm_ioctl_controller_dump_data(scm_data,
+ (struct scm_ioctl_controller_dump_data __user *)args);
+ break;
+
+ case SCM_IOCTL_CONTROLLER_DUMP_COMPLETE:
+ rc = scm_ioctl_controller_dump_complete(scm_data);
+ break;
}
+
return rc;
}

diff --git a/include/uapi/nvdimm/ocxl-scm.h b/include/uapi/nvdimm/ocxl-scm.h
index b34dd1ba06ff..abd2dc9ea112 100644
--- a/include/uapi/nvdimm/ocxl-scm.h
+++ b/include/uapi/nvdimm/ocxl-scm.h
@@ -38,9 +38,24 @@ struct scm_ioctl_error_log {
__u8 *buf; // pointer to output buffer
};

+struct scm_ioctl_controller_dump_data {
+ __u8 *buf; // pointer to output buffer
+ __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 is no more dump data available.
+ */
+ __u32 offset; // in, Offset within the dump
+ __u64 reserved[8];
+};
+
/* ioctl numbers */
#define SCM_MAGIC 0x5C
/* SCM devices */
#define SCM_IOCTL_ERROR_LOG _IOWR(SCM_MAGIC, 0x01, struct scm_ioctl_error_log)
+#define SCM_IOCTL_CONTROLLER_DUMP _IO(SCM_MAGIC, 0x02)
+#define SCM_IOCTL_CONTROLLER_DUMP_DATA _IOWR(SCM_MAGIC, 0x03, struct scm_ioctl_controller_dump_data)
+#define SCM_IOCTL_CONTROLLER_DUMP_COMPLETE _IO(SCM_MAGIC, 0x04)

#endif /* _UAPI_OCXL_SCM_H */
--
2.23.0