On Sat, 2018-11-24 at 10:47 -0800, Dan Williams wrote:
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.
Fixes: cfe30b872058 ("libnvdimm, pmem: adjust for section collisions with...") Cc: stable@vger.kernel.org Signed-off-by: Dan Williams dan.j.williams@intel.com
drivers/nvdimm/nd-core.h | 2 + drivers/nvdimm/pfn_devs.c | 64 ++++++++++++++++++++++++------------------ drivers/nvdimm/region_devs.c | 41 +++++++++++++++++++++++++++ 3 files changed, 80 insertions(+), 27 deletions(-)
Looks good to me, Reviewed-by: Vishal Verma vishal.l.verma@intel.com
diff --git a/drivers/nvdimm/nd-core.h b/drivers/nvdimm/nd-core.h index 182258f64417..d0c621b32f72 100644 --- a/drivers/nvdimm/nd-core.h +++ b/drivers/nvdimm/nd-core.h @@ -111,6 +111,8 @@ resource_size_t nd_pmem_available_dpa(struct nd_region *nd_region, struct nd_mapping *nd_mapping, resource_size_t *overlap); resource_size_t nd_blk_available_dpa(struct nd_region *nd_region); resource_size_t nd_region_available_dpa(struct nd_region *nd_region); +int nd_region_conflict(struct nd_region *nd_region, resource_size_t start,
resource_size_t size);resource_size_t nvdimm_allocated_dpa(struct nvdimm_drvdata *ndd, struct nd_label_id *label_id); int alias_dpa_busy(struct device *dev, void *data); diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c index 24c64090169e..6f22272e8d80 100644 --- a/drivers/nvdimm/pfn_devs.c +++ b/drivers/nvdimm/pfn_devs.c @@ -649,14 +649,47 @@ static u64 phys_pmem_align_down(struct nd_pfn *nd_pfn, u64 phys) ALIGN_DOWN(phys, nd_pfn->align)); } +/*
- Check if pmem collides with 'System RAM', or other regions when
- section aligned. Trim it accordingly.
- */
+static void trim_pfn_device(struct nd_pfn *nd_pfn, u32 *start_pad, u32 *end_trunc) +{
- struct nd_namespace_common *ndns = nd_pfn->ndns;
- struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
- struct nd_region *nd_region = to_nd_region(nd_pfn->dev.parent);
- const resource_size_t start = nsio->res.start;
- const resource_size_t end = start + resource_size(&nsio->res);
- resource_size_t adjust, size;
- *start_pad = 0;
- *end_trunc = 0;
- adjust = start - PHYS_SECTION_ALIGN_DOWN(start);
- size = resource_size(&nsio->res) + adjust;
- if (region_intersects(start - adjust, size, IORESOURCE_SYSTEM_RAM,
IORES_DESC_NONE) == REGION_MIXED|| nd_region_conflict(nd_region, start - adjust, size))*start_pad = PHYS_SECTION_ALIGN_UP(start) - start;- /* Now check that end of the range does not collide. */
- adjust = PHYS_SECTION_ALIGN_UP(end) - end;
- size = resource_size(&nsio->res) + adjust;
- if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
IORES_DESC_NONE) == REGION_MIXED|| !IS_ALIGNED(end, nd_pfn->align)|| nd_region_conflict(nd_region, start, size + adjust))*end_trunc = end - phys_pmem_align_down(nd_pfn, end);+}
static int nd_pfn_init(struct nd_pfn *nd_pfn) { u32 dax_label_reserve = is_nd_dax(&nd_pfn->dev) ? SZ_128K : 0; struct nd_namespace_common *ndns = nd_pfn->ndns;
- u32 start_pad = 0, end_trunc = 0;
- struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev); resource_size_t start, size;
- struct nd_namespace_io *nsio; struct nd_region *nd_region;
- u32 start_pad, end_trunc; struct nd_pfn_sb *pfn_sb; unsigned long npfns; phys_addr_t offset;
@@ -688,30 +721,7 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) memset(pfn_sb, 0, sizeof(*pfn_sb));
- /*
* Check if pmem collides with 'System RAM' when section aligned and* trim it accordingly*/- nsio = to_nd_namespace_io(&ndns->dev);
- start = PHYS_SECTION_ALIGN_DOWN(nsio->res.start);
- size = resource_size(&nsio->res);
- if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
IORES_DESC_NONE) == REGION_MIXED) {start = nsio->res.start;start_pad = PHYS_SECTION_ALIGN_UP(start) - start;- }
- start = nsio->res.start;
- size = PHYS_SECTION_ALIGN_UP(start + size) - start;
- if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
IORES_DESC_NONE) == REGION_MIXED|| !IS_ALIGNED(start + resource_size(&nsio->res),nd_pfn->align)) {size = resource_size(&nsio->res);end_trunc = start + size - phys_pmem_align_down(nd_pfn,start + size);- }
- trim_pfn_device(nd_pfn, &start_pad, &end_trunc); if (start_pad + end_trunc) dev_info(&nd_pfn->dev, "%s alignment collision, truncate %d bytes\n", dev_name(&ndns->dev), start_pad + end_trunc);
@@ -722,7 +732,7 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) * implementation will limit the pfns advertised through * ->direct_access() to those that are included in the memmap. */
- start += start_pad;
- start = nsio->res.start + start_pad; size = resource_size(&nsio->res); npfns = PFN_SECTION_ALIGN_UP((size - start_pad - end_trunc - SZ_8K) / PAGE_SIZE);
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(®ion_ida);