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authorDan Williams <dan.j.williams@intel.com>2018-11-24 10:47:04 -0800
committerDan Williams <dan.j.williams@intel.com>2018-12-05 14:16:12 -0800
commitae86cbfef3818300f1972e52f67a93211acb0e24 (patch)
treeb36ab8d85a1cbcb9344a0bb29e1d0f18eef23a6b /drivers/nvdimm/region_devs.c
parente3f5df762d4a6ef6326c3c09bc9f89ea8a2eab2c (diff)
downloadlinux-ae86cbfef3818300f1972e52f67a93211acb0e24.tar.bz2
libnvdimm, pfn: Pad pfn namespaces relative to other regions
Commit cfe30b872058 "libnvdimm, pmem: adjust for section collisions with 'System RAM'" enabled Linux to workaround occasions where platform firmware arranges for "System RAM" and "Persistent Memory" to collide within a single section boundary. Unfortunately, as reported in this issue [1], platform firmware can inflict the same collision between persistent memory regions. The approach of interrogating iomem_resource does not work in this case because platform firmware may merge multiple regions into a single iomem_resource range. Instead provide a method to interrogate regions that share the same parent bus. This is a stop-gap until the core-MM can grow support for hotplug on sub-section boundaries. [1]: https://github.com/pmem/ndctl/issues/76 Fixes: cfe30b872058 ("libnvdimm, pmem: adjust for section collisions with...") Cc: <stable@vger.kernel.org> Reported-by: Patrick Geary <patrickg@supermicro.com> Tested-by: Patrick Geary <patrickg@supermicro.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/nvdimm/region_devs.c')
-rw-r--r--drivers/nvdimm/region_devs.c41
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index 174a418cb171..e7377f1028ef 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -1184,6 +1184,47 @@ int nvdimm_has_cache(struct nd_region *nd_region)
}
EXPORT_SYMBOL_GPL(nvdimm_has_cache);
+struct conflict_context {
+ struct nd_region *nd_region;
+ resource_size_t start, size;
+};
+
+static int region_conflict(struct device *dev, void *data)
+{
+ struct nd_region *nd_region;
+ struct conflict_context *ctx = data;
+ resource_size_t res_end, region_end, region_start;
+
+ if (!is_memory(dev))
+ return 0;
+
+ nd_region = to_nd_region(dev);
+ if (nd_region == ctx->nd_region)
+ return 0;
+
+ res_end = ctx->start + ctx->size;
+ region_start = nd_region->ndr_start;
+ region_end = region_start + nd_region->ndr_size;
+ if (ctx->start >= region_start && ctx->start < region_end)
+ return -EBUSY;
+ if (res_end > region_start && res_end <= region_end)
+ return -EBUSY;
+ return 0;
+}
+
+int nd_region_conflict(struct nd_region *nd_region, resource_size_t start,
+ resource_size_t size)
+{
+ struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
+ struct conflict_context ctx = {
+ .nd_region = nd_region,
+ .start = start,
+ .size = size,
+ };
+
+ return device_for_each_child(&nvdimm_bus->dev, &ctx, region_conflict);
+}
+
void __exit nd_region_devs_exit(void)
{
ida_destroy(&region_ida);