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authorDan Williams <dan.j.williams@intel.com>2018-03-21 15:12:07 -0700
committerDan Williams <dan.j.williams@intel.com>2018-03-21 15:12:07 -0700
commitfe9a552e715dfe5167d52deb74ea16335896bdaf (patch)
treef47ac26b9a82ebde8c4a1380fe1ea1571e52ac3b /drivers/acpi
parent896196dc4e419a9d0782404e0befac17d638fc01 (diff)
libnvdimm, nfit: fix persistence domain reporting
The persistence domain is a point in the platform where once writes reach that destination the platform claims it will make them persistent relative to power loss. In the ACPI NFIT this is currently communicated as 2 bits in the "NFIT - Platform Capabilities Structure". The bits comprise a hierarchy, i.e. bit0 "CPU Cache Flush to NVDIMM Durability on Power Loss Capable" implies bit1 "Memory Controller Flush to NVDIMM Durability on Power Loss Capable". Commit 96c3a239054a "libnvdimm: expose platform persistence attr..." shows the persistence domain as flags, but it's really an enumerated hierarchy. Fix this newly introduced user ABI to show the closest available persistence domain before userspace develops dependencies on seeing, or needing to develop code to tolerate, the raw NFIT flags communicated through the libnvdimm-generic region attribute. Fixes: 96c3a239054a ("libnvdimm: expose platform persistence attr...") Reviewed-by: Dave Jiang <dave.jiang@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/nfit/core.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index bbe48ad20886..eb09ef55c38a 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -2675,10 +2675,14 @@ static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc,
else
ndr_desc->numa_node = NUMA_NO_NODE;
- if(acpi_desc->platform_cap & ACPI_NFIT_CAPABILITY_CACHE_FLUSH)
+ /*
+ * Persistence domain bits are hierarchical, if
+ * ACPI_NFIT_CAPABILITY_CACHE_FLUSH is set then
+ * ACPI_NFIT_CAPABILITY_MEM_FLUSH is implied.
+ */
+ if (acpi_desc->platform_cap & ACPI_NFIT_CAPABILITY_CACHE_FLUSH)
set_bit(ND_REGION_PERSIST_CACHE, &ndr_desc->flags);
-
- if (acpi_desc->platform_cap & ACPI_NFIT_CAPABILITY_MEM_FLUSH)
+ else if (acpi_desc->platform_cap & ACPI_NFIT_CAPABILITY_MEM_FLUSH)
set_bit(ND_REGION_PERSIST_MEMCTRL, &ndr_desc->flags);
list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list) {