On Mon, Jan 3, 2022 at 12:11 PM <[email protected]> wrote:
>
> From: Alison Schofield <[email protected]>
>
> The command 'cxl set-partition-info' operates on a CXL memdev,
> or a set of memdevs, allowing the user to change the partition
> layout of the device.
>
> Synopsis:
> Usage: cxl set-partition-info <mem0> [<mem1>..<memN>] [<options>]
>
> -v, --verbose turn on debug
> -s, --volatile_size <n>
> next volatile partition size in bytes
>
> The MAN page explains how to find partitioning capabilities and
> restrictions.
>
> Signed-off-by: Alison Schofield <[email protected]>
> ---
> Documentation/cxl/cxl-set-partition-info.txt | 27 ++++++
> Documentation/cxl/partition-description.txt | 15 ++++
> Documentation/cxl/partition-options.txt | 19 +++++
> Documentation/cxl/Makefile.am | 3 +-
> cxl/builtin.h | 1 +
> cxl/cxl.c | 1 +
> cxl/memdev.c | 89 ++++++++++++++++++++
> 7 files changed, 154 insertions(+), 1 deletion(-)
> create mode 100644 Documentation/cxl/cxl-set-partition-info.txt
> create mode 100644 Documentation/cxl/partition-description.txt
> create mode 100644 Documentation/cxl/partition-options.txt
>
> diff --git a/Documentation/cxl/cxl-set-partition-info.txt
> b/Documentation/cxl/cxl-set-partition-info.txt
> new file mode 100644
> index 0000000..32418b6
> --- /dev/null
> +++ b/Documentation/cxl/cxl-set-partition-info.txt
> @@ -0,0 +1,27 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +cxl-set-partition-info(1)
> +=========================
> +
> +NAME
> +----
> +cxl-set-partition-info - set the partitioning between volatile and
> persistent capacity on a CXL memdev
> +
> +SYNOPSIS
> +--------
> +[verse]
> +'cxl set-partition-info <mem> [ [<mem1>..<memN>] [<options>]'
> +
> +include::partition-description.txt[]
> +Partition the device on the next device reset using the volatile capacity
> +requested. Using this command to change the size of the persistent capacity
> +shall result in the loss of stored data.
> +
> +OPTIONS
> +-------
> +include::partition-options.txt[]
> +
> +SEE ALSO
> +--------
> +linkcxl:cxl-list[1],
> +CXL-2.0 8.2.9.5.2
> diff --git a/Documentation/cxl/partition-description.txt
> b/Documentation/cxl/partition-description.txt
> new file mode 100644
> index 0000000..b3efac8
> --- /dev/null
> +++ b/Documentation/cxl/partition-description.txt
> @@ -0,0 +1,15 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +DESCRIPTION
> +-----------
> +Partition the device into volatile and persistent capacity. The change
> +in partitioning will become the “next” configuration, to become active
> +on the next device reset.
> +
> +Use "cxl list -m <memdev> -P" to examine the partition capacities
> +supported on a device. Paritionable capacity must exist on the
> +device. A partition_alignment of zero means no partitionable
> +capacity is available.
> +
> +Using this command to change the size of the persistent capacity shall
> +result in the loss of data stored.
> diff --git a/Documentation/cxl/partition-options.txt
> b/Documentation/cxl/partition-options.txt
> new file mode 100644
> index 0000000..84e49c9
> --- /dev/null
> +++ b/Documentation/cxl/partition-options.txt
> @@ -0,0 +1,19 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +<memory device(s)>::
> +include::memdev-option.txt[]
> +
> +-s::
> +--size=::
> + Size in bytes of the volatile partition requested.
> +
> + Size must align to the devices partition_alignment.
> + Use 'cxl list -m <memdev> -P' to find partition_alignment.
> +
> + Size must be less than or equal to the devices partitionable bytes.
> + (total_capacity - volatile_only_capacity - persistent_only_capacity)
> + Use 'cxl list -m <memdev> -P' to find *_capacity values.
> +
> +-v::
> + Turn on verbose debug messages in the library (if libcxl was built
> with
> + logging and debug enabled).
> diff --git a/Documentation/cxl/Makefile.am b/Documentation/cxl/Makefile.am
> index efabaa3..c5faf04 100644
> --- a/Documentation/cxl/Makefile.am
> +++ b/Documentation/cxl/Makefile.am
> @@ -22,7 +22,8 @@ man1_MANS = \
> cxl-list.1 \
> cxl-read-labels.1 \
> cxl-write-labels.1 \
> - cxl-zero-labels.1
> + cxl-zero-labels.1 \
> + cxl-set-partition-info.1
>
> EXTRA_DIST = $(man1_MANS)
>
> diff --git a/cxl/builtin.h b/cxl/builtin.h
> index 78eca6e..7f11f28 100644
> --- a/cxl/builtin.h
> +++ b/cxl/builtin.h
> @@ -10,4 +10,5 @@ int cmd_read_labels(int argc, const char **argv, struct
> cxl_ctx *ctx);
> int cmd_zero_labels(int argc, const char **argv, struct cxl_ctx *ctx);
> int cmd_init_labels(int argc, const char **argv, struct cxl_ctx *ctx);
> int cmd_check_labels(int argc, const char **argv, struct cxl_ctx *ctx);
> +int cmd_set_partition_info(int argc, const char **argv, struct cxl_ctx *ctx);
> #endif /* _CXL_BUILTIN_H_ */
> diff --git a/cxl/cxl.c b/cxl/cxl.c
> index 4b1661d..3153cf0 100644
> --- a/cxl/cxl.c
> +++ b/cxl/cxl.c
> @@ -64,6 +64,7 @@ static struct cmd_struct commands[] = {
> { "zero-labels", .c_fn = cmd_zero_labels },
> { "read-labels", .c_fn = cmd_read_labels },
> { "write-labels", .c_fn = cmd_write_labels },
> + { "set-partition-info", .c_fn = cmd_set_partition_info },
> };
>
> int main(int argc, const char **argv)
> diff --git a/cxl/memdev.c b/cxl/memdev.c
> index 5ee38e5..fa63317 100644
> --- a/cxl/memdev.c
> +++ b/cxl/memdev.c
> @@ -6,6 +6,7 @@
> #include <unistd.h>
> #include <limits.h>
> #include <util/log.h>
> +#include <util/size.h>
> #include <util/filter.h>
> #include <cxl/libcxl.h>
> #include <util/parse-options.h>
> @@ -23,6 +24,7 @@ static struct parameters {
> unsigned len;
> unsigned offset;
> bool verbose;
> + unsigned long long volatile_size;
> } param;
>
> #define fail(fmt, ...) \
> @@ -47,6 +49,10 @@ OPT_UINTEGER('s', "size", ¶m.len, "number of label
> bytes to operate"), \
> OPT_UINTEGER('O', "offset", ¶m.offset, \
> "offset into the label area to start operation")
>
> +#define SET_PARTITION_OPTIONS() \
> +OPT_U64('s', "volatile_size", ¶m.volatile_size, \
> + "next volatile partition size in bytes")
> +
> static const struct option read_options[] = {
> BASE_OPTIONS(),
> LABEL_OPTIONS(),
> @@ -67,6 +73,12 @@ static const struct option zero_options[] = {
> OPT_END(),
> };
>
> +static const struct option set_partition_options[] = {
> + BASE_OPTIONS(),
> + SET_PARTITION_OPTIONS(),
> + OPT_END(),
> +};
> +
> static int action_zero(struct cxl_memdev *memdev, struct action_context
> *actx)
> {
> size_t size;
> @@ -174,6 +186,73 @@ out:
> return rc;
> }
>
> +static int validate_partition(struct cxl_memdev *memdev,
> + unsigned long long volatile_request)
> +{
> + unsigned long long total_cap, volatile_only, persistent_only;
> + unsigned long long partitionable_bytes, partition_align_bytes;
> + const char *devname = cxl_memdev_get_devname(memdev);
> + struct cxl_cmd *cmd;
> + int rc;
> +
> + cmd = cxl_cmd_new_identify(memdev);
> + if (!cmd)
> + return -ENXIO;
> + rc = cxl_cmd_submit(cmd);
> + if (rc < 0)
> + goto err;
> + rc = cxl_cmd_get_mbox_status(cmd);
> + if (rc != 0)
> + goto err;
> +
> + partition_align_bytes = cxl_cmd_identify_get_partition_align(cmd);
> + if (partition_align_bytes == 0) {
> + fprintf(stderr, "%s: no partitionable capacity\n", devname);
> + rc = -EINVAL;
> + goto err;
> + }
> +
> + total_cap = cxl_cmd_identify_get_total_capacity(cmd);
> + volatile_only = cxl_cmd_identify_get_volatile_only_capacity(cmd);
> + persistent_only = cxl_cmd_identify_get_persistent_only_capacity(cmd);
> +
> + partitionable_bytes = total_cap - volatile_only - persistent_only;
> +
> + if (volatile_request > partitionable_bytes) {
> + fprintf(stderr, "%s: volatile size %lld exceeds partitionable
> capacity %lld\n",
> + devname, volatile_request, partitionable_bytes);
> + rc = -EINVAL;
> + goto err;
> + }
> + if (!IS_ALIGNED(volatile_request, partition_align_bytes)) {
> + fprintf(stderr, "%s: volatile size %lld is not partition
> aligned %lld\n",
> + devname, volatile_request, partition_align_bytes);
> + rc = -EINVAL;
> + }
> +err:
> + cxl_cmd_unref(cmd);
> + return rc;
> +}
> +
> +static int action_set_partition(struct cxl_memdev *memdev,
> + struct action_context *actx)
> +{
> + const char *devname = cxl_memdev_get_devname(memdev);
> + unsigned long long volatile_request;
> + int rc;
> +
> + volatile_request = param.volatile_size;
> +
> + rc = validate_partition(memdev, volatile_request);
> + if (rc)
> + return rc;
> +
> + rc = cxl_memdev_set_partition_info(memdev, volatile_request, 0);
> + if (rc)
> + fprintf(stderr, "%s error: %s\n", devname, strerror(-rc));
> + return rc;
One of the conventions from ndctl is that any command that modifies an
object should also emit the updated state of that object in JSON. For
example, "ndctl reconfigure-namespace" arranges for:
unsigned long flags = UTIL_JSON_DAX | UTIL_JSON_DAX_DEVS;
struct json_object *jndns;
if (isatty(1))
flags |= UTIL_JSON_HUMAN;
jndns = util_namespace_to_json(ndns, flags);
if (jndns)
printf("%s\n", json_object_to_json_string_ext(jndns,
JSON_C_TO_STRING_PRETTY));
...to dump the updated state of the namespace, so a similar
util_memdev_to_json() seems appropriate here. However, perhaps that
can come later. I have work-in-progress patches to move the core of
cxl/list.c to a cxl_filter_walk() helper that would allow you to just
call that to dump a listing for all the memdevs that were passed on
the command line.
