On Tue, Mar 20, 2018 at 3:50 PM, Dave Jiang <dave.ji...@intel.com> wrote:
> Adding helper functions to iterate through sysfs region persistence domain
> attribute. The region will display the domain with the most persistence for
> the
> region. The bus will display the domain attribute with the least persistence
> amongst all the regions. ndctl_bus_get_persistence_domain() and
> ndctl_region_get_persistence_domain are exported. ndctl list will also display
> the region persistence domain as well.
>
> Signed-off-by: Dave Jiang <dave.ji...@intel.com>
> ---
> v5:
> - space out ndctl_persistence_domain for future attributes
>
> v4:
> - change enum ndctl_persistence to enum ndctl_persistence_domain
>
> v3:
> - fixed up return types per Ross's comments
> - removed persistence_domain for bus and calculate on the fly per Dan's
> comment
>
> v2:
> - Simplied scanning of persistence domain from Ross's comments.
>
>
> ndctl/lib/libndctl.c | 85
> ++++++++++++++++++++++++++++++++++++++++++++++++
> ndctl/lib/libndctl.sym | 2 +
> ndctl/libndctl.h | 12 +++++++
> ndctl/list.c | 16 +++++++++
> 4 files changed, 115 insertions(+)
>
> diff --git a/ndctl/lib/libndctl.c b/ndctl/lib/libndctl.c
> index a165e697..d97f1501 100644
> --- a/ndctl/lib/libndctl.c
> +++ b/ndctl/lib/libndctl.c
> @@ -180,6 +180,7 @@ struct ndctl_region {
> } iset;
> FILE *badblocks;
> struct badblock bb;
> + enum ndctl_persistence_domain persistence_domain;
> };
>
> /**
> @@ -916,6 +917,22 @@ NDCTL_EXPORT struct ndctl_bus
> *ndctl_bus_get_by_provider(struct ndctl_ctx *ctx,
> return NULL;
> }
>
> +NDCTL_EXPORT enum ndctl_persistence_domain
> +ndctl_bus_get_persistence_domain(struct ndctl_bus *bus)
> +{
> + struct ndctl_region *region;
> + enum ndctl_persistence_domain pd = PERSISTENCE_UNKNOWN;
> +
> + /* iterate through region to get the region persistence domain */
> + ndctl_region_foreach(bus, region) {
> + /* we are looking for the least persistence domain */
> + if (pd > region->persistence_domain)
> + pd = region->persistence_domain;
> + }
> +
> + return pd;
> +}
> +
> NDCTL_EXPORT struct ndctl_btt *ndctl_region_get_btt_seed(struct ndctl_region
> *region)
> {
> struct ndctl_ctx *ctx = ndctl_region_get_ctx(region);
> @@ -1755,6 +1772,62 @@ static int region_set_type(struct ndctl_region
> *region, char *path)
> return 0;
> }
>
> +static enum ndctl_persistence_domain region_get_pd_type(char *name)
> +{
> + if (strncmp("cpu_cache", name, 9) == 0)
> + return PERSISTENCE_CPU_CACHE;
> + else if (strncmp("memory_controller", name, 17) == 0)
> + return PERSISTENCE_MEM_CTRL;
> + else
> + return PERSISTENCE_UNKNOWN;
> +}
> +
> +static int region_persistence_scan(struct ndctl_region *region)
> +{
> + struct ndctl_ctx *ctx = ndctl_region_get_ctx(region);
> + char *pd_path;
> + FILE *pf;
> + char buf[64];
> + int rc = 0;
> + enum ndctl_persistence_domain pd = PERSISTENCE_NONE;
> +
> + region->persistence_domain = PERSISTENCE_NONE;
> + if (asprintf(&pd_path, "%s/persistence_domain",
> + region->region_path) < 0) {
> + rc = -errno;
> + err(ctx, "region persist domain path allocation failure\n");
> + return rc;
> + }
> +
> + pf = fopen(pd_path, "re");
> + if (!pf) {
> + rc = -errno;
> + free(pd_path);
> + return rc;
> + }
> +
> + do {
> + rc = fscanf(pf, "%s", buf);
> + if (rc == EOF) {
> + if (ferror(pf)) {
> + rc = -errno;
> + goto out;
> + }
> + } else if (rc == 1)
> + pd = region_get_pd_type(buf);
> +
> + if (region->persistence_domain < pd)
> + region->persistence_domain = pd;
> + } while (rc != EOF);
I would expect sysfs_read_attr() here? I don't otherwise see a reason
to have special case code for this attribute.
> +
> + rc = 0;
> +
> +out:
> + fclose(pf);
> + free(pd_path);
> + return rc;
> +}
> +
> static void *add_region(void *parent, int id, const char *region_base)
> {
> char buf[SYSFS_ATTR_SIZE];
> @@ -1831,6 +1904,12 @@ static void *add_region(void *parent, int id, const
> char *region_base)
> list_add(&bus->regions, ®ion->list);
>
> free(path);
> +
> + /* get the persistence domain attribs */
> + if (region_persistence_scan(region) < 0)
> + err(ctx, "%s: region persistence scan failed\n",
> + ndctl_region_get_devname(region));
> +
> return region;
>
> err_read:
> @@ -2093,6 +2172,12 @@ NDCTL_EXPORT struct badblock
> *ndctl_region_get_first_badblock(struct ndctl_regio
> return ndctl_region_get_next_badblock(region);
> }
>
> +NDCTL_EXPORT enum ndctl_persistence_domain
> +ndctl_region_get_persistence_domain(struct ndctl_region *region)
> +{
> + return region->persistence_domain;
> +}
> +
> static struct nd_cmd_vendor_tail *to_vendor_tail(struct ndctl_cmd *cmd)
> {
> struct nd_cmd_vendor_tail *tail = (struct nd_cmd_vendor_tail *)
> diff --git a/ndctl/lib/libndctl.sym b/ndctl/lib/libndctl.sym
> index 21276614..3209aefe 100644
> --- a/ndctl/lib/libndctl.sym
> +++ b/ndctl/lib/libndctl.sym
> @@ -350,4 +350,6 @@ global:
> ndctl_dimm_cmd_new_ack_shutdown_count;
> ndctl_region_get_numa_node;
> ndctl_dimm_fw_update_supported;
> + ndctl_region_get_persistence_domain;
> + ndctl_bus_get_persistence_domain;
> } LIBNDCTL_14;
> diff --git a/ndctl/libndctl.h b/ndctl/libndctl.h
> index f3a27411..eaa3af5f 100644
> --- a/ndctl/libndctl.h
> +++ b/ndctl/libndctl.h
> @@ -115,6 +115,8 @@ int ndctl_bus_is_cmd_supported(struct ndctl_bus *bus, int
> cmd);
> unsigned int ndctl_bus_get_revision(struct ndctl_bus *bus);
> unsigned int ndctl_bus_get_id(struct ndctl_bus *bus);
> const char *ndctl_bus_get_provider(struct ndctl_bus *bus);
> +enum ndctl_persistence_domain ndctl_bus_get_persistence_domain(
> + struct ndctl_bus *bus);
> int ndctl_bus_wait_probe(struct ndctl_bus *bus);
> int ndctl_bus_wait_for_scrub_completion(struct ndctl_bus *bus);
> unsigned int ndctl_bus_get_scrub_count(struct ndctl_bus *bus);
> @@ -305,6 +307,14 @@ struct badblock {
> unsigned long long offset;
> unsigned int len;
> };
> +
> +enum ndctl_persistence_domain {
> + PERSISTENCE_NONE = 0,
> + PERSISTENCE_MEM_CTRL = 10,
> + PERSISTENCE_CPU_CACHE = 20,
> + PERSISTENCE_UNKNOWN = INT32_MAX,
Why INT32_MAX and not INT_MAX? Let's stick to limits.h definitions.
> +};
> +
> struct ndctl_region;
> struct ndctl_region *ndctl_region_get_first(struct ndctl_bus *bus);
> struct ndctl_region *ndctl_region_get_next(struct ndctl_region *region);
> @@ -347,6 +357,8 @@ struct ndctl_region
> *ndctl_bus_get_region_by_physical_address(struct ndctl_bus *
> for (dimm = ndctl_region_get_first_dimm(region); \
> dimm != NULL; \
> dimm = ndctl_region_get_next_dimm(region, dimm))
> +enum ndctl_persistence_domain ndctl_region_get_persistence_domain(
> + struct ndctl_region *region);
> int ndctl_region_is_enabled(struct ndctl_region *region);
> int ndctl_region_enable(struct ndctl_region *region);
> int ndctl_region_disable_invalidate(struct ndctl_region *region);
> diff --git a/ndctl/list.c b/ndctl/list.c
> index fe8036ea..c9f4b74d 100644
> --- a/ndctl/list.c
> +++ b/ndctl/list.c
> @@ -73,6 +73,7 @@ static struct json_object *region_to_json(struct
> ndctl_region *region,
> struct ndctl_interleave_set *iset;
> struct ndctl_mapping *mapping;
> unsigned int bb_count = 0;
> + enum ndctl_persistence_domain pd;
> int numa;
>
> if (!jregion)
> @@ -174,6 +175,21 @@ static struct json_object *region_to_json(struct
> ndctl_region *region,
> if ((flags & UTIL_JSON_MEDIA_ERRORS) && jbbs)
> json_object_object_add(jregion, "badblocks", jbbs);
>
> + pd = ndctl_region_get_persistence_domain(region);
> + switch (pd) {
> + case PERSISTENCE_CPU_CACHE:
Small nit, please use kernel coding style and line up the 'case' with
the 'switch'.
> + jobj = json_object_new_string("cpu_cache");
> + break;
> + case PERSISTENCE_MEM_CTRL:
> + jobj = json_object_new_string("memory_controller");
> + break;
> + default:
> + jobj = NULL;
Let's go ahead and print "unknown" for this case. I want people using
fake pmem to realize it, and otherwise encourage BIOS implementations
to publish the platform capabilities table to get rid of the scary
'"persistence_domain":"unknown"' messages. This would also let us
deprecate the kernel warning message about persistence which is easy
to overlook.
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