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.
The expected flow of operations are:
1. IOCTL_OCXL_PMEM_CONTROLLER_DUMP to request the controller to take
a dump. This IOCTL will complete after the dump is available for
collection.
2. IOCTL_OCXL_PMEM_CONTROLLER_DUMP_DATA called repeatedly to fetch
chunks from the buffer
3. IOCTL_OCXL_PMEM_CONTROLLER_DUMP_COMPLETE to notify the controller
that it can free any internal resources used for the dump
Signed-off-by: Alastair D'Silva <alast...@d-silva.org>
---
drivers/nvdimm/ocxl/main.c | 161 +++++++++++++++++++++++++++++++++
include/uapi/nvdimm/ocxlpmem.h | 16 ++++
2 files changed, 177 insertions(+)
diff --git a/drivers/nvdimm/ocxl/main.c b/drivers/nvdimm/ocxl/main.c
index e6be0029f658..d0db358ded43 100644
--- a/drivers/nvdimm/ocxl/main.c
+++ b/drivers/nvdimm/ocxl/main.c
@@ -566,6 +566,153 @@ static int ioctl_error_log(struct ocxlpmem *ocxlpmem,
return 0;
}
+/**
+ * controller_dump_header_parse() - Parse the first 64 bits of the controller
dump command response
+ * @ocxlpmem: the device metadata
+ * @length: out, returns the number of bytes in the response (excluding the 64
bit header)
+ */
+static int controller_dump_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 != 0x4344) { // 'CD'
+ dev_err(&ocxlpmem->dev,
+ "Bad data identifier for error log data, expected 'CD',
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 ioctl_controller_dump_data(struct ocxlpmem *ocxlpmem,
+ struct
ioctl_ocxlpmem_controller_dump_data __user *uarg)
+{
+ struct ioctl_ocxlpmem_controller_dump_data args;
+ u64 __user *buf;
+ u16 i, buf_size;
+ u64 val;
+ int rc;
+
+ if (copy_from_user(&args, uarg, sizeof(args)))
+ return -EFAULT;
+
+ if (args.buf_size % sizeof(u64))
+ return -EINVAL;
+
+ if (args.buf_size > ocxlpmem->admin_command.data_size)
+ return -EINVAL;
+
+ buf = (u64 *)args.buf_ptr;
+
+ mutex_lock(&ocxlpmem->admin_command.lock);
+
+ val = ((u64)args.offset) << 32;
+ val |= args.buf_size;
+ rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu,
+ ocxlpmem->admin_command.request_offset +
0x08,
+ OCXL_LITTLE_ENDIAN, val);
+ if (rc)
+ goto out;
+
+ rc = admin_command_execute(ocxlpmem, ADMIN_COMMAND_CONTROLLER_DUMP);
+ if (rc)
+ goto out;
+ if (rc != STATUS_SUCCESS) {
+ warn_status(ocxlpmem,
+ "Unexpected status from controller dump",
+ rc);
+ goto out;
+ }
+
+ rc = controller_dump_header_parse(ocxlpmem, &buf_size);
+ if (rc)
+ goto out;
+
+ buf_size = min((u16)(buf_size + sizeof(u64)), args.buf_size);
+
+ for (i = 0; i < buf_size / 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 (copy_to_user(&buf[i], &val, sizeof(u64))) {
+ rc = -EFAULT;
+ goto out;
+ }
+ }
+
+ args.buf_size = buf_size;
+
+ if (copy_to_user(uarg, &args, sizeof(args))) {
+ rc = -EFAULT;
+ goto out;
+ }
+
+ rc = admin_response_handled(ocxlpmem);
+ if (rc)
+ goto out;
+
+out:
+ mutex_unlock(&ocxlpmem->admin_command.lock);
+ return rc;
+}
+
+int request_controller_dump(struct ocxlpmem *ocxlpmem)
+{
+ int rc;
+ u64 busy = 1;
+
+ rc = ocxl_global_mmio_set64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_CHIC,
+ OCXL_LITTLE_ENDIAN,
+ GLOBAL_MMIO_CHI_CDA);
+ if (rc)
+ return rc;
+
+ rc = ocxl_global_mmio_set64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_HCI,
+ OCXL_LITTLE_ENDIAN,
+ GLOBAL_MMIO_HCI_CONTROLLER_DUMP);
+ if (rc)
+ return rc;
+
+ while (busy) {
+ rc = ocxl_global_mmio_read64(ocxlpmem->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 ioctl_controller_dump_complete(struct ocxlpmem *ocxlpmem)
+{
+ return ocxl_global_mmio_set64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_HCI,
+ OCXL_LITTLE_ENDIAN,
+ GLOBAL_MMIO_HCI_CONTROLLER_DUMP_COLLECTED);
+}
+
static long file_ioctl(struct file *file, unsigned int cmd, unsigned long args)
{
struct ocxlpmem *ocxlpmem = file->private_data;
@@ -576,7 +723,21 @@ static long file_ioctl(struct file *file, unsigned int
cmd, unsigned long args)
rc = ioctl_error_log(ocxlpmem,
(struct ioctl_ocxlpmem_error_log __user
*)args);
break;
+
+ case IOCTL_OCXLPMEM_CONTROLLER_DUMP:
+ rc = request_controller_dump(ocxlpmem);
+ break;
+
+ case IOCTL_OCXLPMEM_CONTROLLER_DUMP_DATA:
+ rc = ioctl_controller_dump_data(ocxlpmem,
+ (struct
ioctl_ocxlpmem_controller_dump_data __user *)args);
+ break;
+
+ case IOCTL_OCXLPMEM_CONTROLLER_DUMP_COMPLETE:
+ rc = ioctl_controller_dump_complete(ocxlpmem);
+ break;
}
+
return rc;
}
diff --git a/include/uapi/nvdimm/ocxlpmem.h b/include/uapi/nvdimm/ocxlpmem.h
index 5d3a03ea1e08..05e2b3f7b27c 100644
--- a/include/uapi/nvdimm/ocxlpmem.h
+++ b/include/uapi/nvdimm/ocxlpmem.h
@@ -38,9 +38,25 @@ struct ioctl_ocxlpmem_error_log {
__u64 reserved2[2];
};
+struct ioctl_ocxlpmem_controller_dump_data {
+ __u64 buf_ptr; /* coerced 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.
+ */
+ __u16 reserved0;
+ __u32 offset; /* in, Offset within the dump */
+ __u64 reserved[8];
+};
+
/* ioctl numbers */
#define OCXLPMEM_MAGIC 0xCA
/* OpenCAPI Persistent memory devices */
#define IOCTL_OCXLPMEM_ERROR_LOG _IOWR(OCXLPMEM_MAGIC,
0x30, struct ioctl_ocxlpmem_error_log)
+#define IOCTL_OCXLPMEM_CONTROLLER_DUMP _IO(OCXLPMEM_MAGIC,
0x31)
+#define IOCTL_OCXLPMEM_CONTROLLER_DUMP_DATA _IOWR(OCXLPMEM_MAGIC,
0x32, struct ioctl_ocxlpmem_controller_dump_data)
+#define IOCTL_OCXLPMEM_CONTROLLER_DUMP_COMPLETE
_IO(OCXLPMEM_MAGIC, 0x33)
#endif /* _UAPI_OCXL_SCM_H */
--
2.24.1
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