The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0731de476a37c33485af82d64041c9d193208df8 Mon Sep 17 00:00:00 2001
From: Dan Williams dan.j.williams@intel.com Date: Wed, 21 Mar 2018 21:22:34 -0700 Subject: [PATCH] nfit: skip region registration for incomplete control regions
Per the ACPI specification the only functional purpose for a DIMM Control Region to be mapped into the system physical address space, from an OSPM perspective, is to support block-apertures. However, there are some BIOSen that publish DIMM Control Region SPA entries for pre-boot environment consumption. Undo the kernel policy of generating disabled 'ndblk' regions when this configuration is detected.
Cc: stable@vger.kernel.org Fixes: 1f7df6f88b92 ("libnvdimm, nfit: regions (block-data-window...)") Reviewed-by: Toshi Kani toshi.kani@hpe.com Signed-off-by: Dan Williams dan.j.williams@intel.com
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 39ad06143e78..4530d89044db 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -2578,7 +2578,7 @@ static int acpi_nfit_init_mapping(struct acpi_nfit_desc *acpi_desc, struct acpi_nfit_system_address *spa = nfit_spa->spa; struct nd_blk_region_desc *ndbr_desc; struct nfit_mem *nfit_mem; - int blk_valid = 0, rc; + int rc;
if (!nvdimm) { dev_err(acpi_desc->dev, "spa%d dimm: %#x not found\n", @@ -2598,15 +2598,14 @@ static int acpi_nfit_init_mapping(struct acpi_nfit_desc *acpi_desc, if (!nfit_mem || !nfit_mem->bdw) { dev_dbg(acpi_desc->dev, "spa%d %s missing bdw\n", spa->range_index, nvdimm_name(nvdimm)); - } else { - mapping->size = nfit_mem->bdw->capacity; - mapping->start = nfit_mem->bdw->start_address; - ndr_desc->num_lanes = nfit_mem->bdw->windows; - blk_valid = 1; + break; }
+ mapping->size = nfit_mem->bdw->capacity; + mapping->start = nfit_mem->bdw->start_address; + ndr_desc->num_lanes = nfit_mem->bdw->windows; ndr_desc->mapping = mapping; - ndr_desc->num_mappings = blk_valid; + ndr_desc->num_mappings = 1; ndbr_desc = to_blk_region_desc(ndr_desc); ndbr_desc->enable = acpi_nfit_blk_region_enable; ndbr_desc->do_io = acpi_desc->blk_do_io;