From 14e494542636b7a685c5bf27e695e3bb9ec3fe7d Mon Sep 17 00:00:00 2001 From: Vishal Verma Date: Wed, 28 Jun 2017 14:25:00 -0600 Subject: libnvdimm, btt: BTT updates for UEFI 2.7 format The UEFI 2.7 specification defines an updated BTT metadata format, bumping the revision to 2.0. Add support for the new format, while retaining compatibility for the old 1.1 format. Cc: Toshi Kani Cc: Linda Knippers Cc: Dan Williams Signed-off-by: Vishal Verma Signed-off-by: Dan Williams --- drivers/nvdimm/namespace_devs.c | 61 +++++++++++++++++++++++++++++++++++++++-- 1 file changed, 59 insertions(+), 2 deletions(-) (limited to 'drivers/nvdimm/namespace_devs.c') diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c index f05d9b0672bf..c96e31330213 100644 --- a/drivers/nvdimm/namespace_devs.c +++ b/drivers/nvdimm/namespace_devs.c @@ -1411,6 +1411,58 @@ static ssize_t dpa_extents_show(struct device *dev, } static DEVICE_ATTR_RO(dpa_extents); +static int btt_claim_class(struct device *dev) +{ + struct nd_region *nd_region = to_nd_region(dev->parent); + int i, loop_bitmask = 0; + + for (i = 0; i < nd_region->ndr_mappings; i++) { + struct nd_mapping *nd_mapping = &nd_region->mapping[i]; + struct nvdimm_drvdata *ndd = to_ndd(nd_mapping); + struct nd_namespace_index *nsindex; + + nsindex = to_namespace_index(ndd, ndd->ns_current); + if (nsindex == NULL) + loop_bitmask |= 1; + else { + /* check whether existing labels are v1.1 or v1.2 */ + if (__le16_to_cpu(nsindex->major) == 1 + && __le16_to_cpu(nsindex->minor) == 1) + loop_bitmask |= 2; + else + loop_bitmask |= 4; + } + } + /* + * If nsindex is null loop_bitmask's bit 0 will be set, and if an index + * block is found, a v1.1 label for any mapping will set bit 1, and a + * v1.2 label will set bit 2. + * + * At the end of the loop, at most one of the three bits must be set. + * If multiple bits were set, it means the different mappings disagree + * about their labels, and this must be cleaned up first. + * + * If all the label index blocks are found to agree, nsindex of NULL + * implies labels haven't been initialized yet, and when they will, + * they will be of the 1.2 format, so we can assume BTT2.0 + * + * If 1.1 labels are found, we enforce BTT1.1, and if 1.2 labels are + * found, we enforce BTT2.0 + * + * If the loop was never entered, default to BTT1.1 (legacy namespaces) + */ + switch (loop_bitmask) { + case 0: + case 2: + return NVDIMM_CCLASS_BTT; + case 1: + case 4: + return NVDIMM_CCLASS_BTT2; + default: + return -ENXIO; + } +} + static ssize_t holder_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -1433,7 +1485,7 @@ static ssize_t __holder_class_store(struct device *dev, const char *buf) return -EBUSY; if (strcmp(buf, "btt") == 0 || strcmp(buf, "btt\n") == 0) - ndns->claim_class = NVDIMM_CCLASS_BTT; + ndns->claim_class = btt_claim_class(dev); else if (strcmp(buf, "pfn") == 0 || strcmp(buf, "pfn\n") == 0) ndns->claim_class = NVDIMM_CCLASS_PFN; else if (strcmp(buf, "dax") == 0 || strcmp(buf, "dax\n") == 0) @@ -1443,6 +1495,10 @@ static ssize_t __holder_class_store(struct device *dev, const char *buf) else return -EINVAL; + /* btt_claim_class() could've returned an error */ + if (ndns->claim_class < 0) + return ndns->claim_class; + return 0; } @@ -1474,7 +1530,8 @@ static ssize_t holder_class_show(struct device *dev, device_lock(dev); if (ndns->claim_class == NVDIMM_CCLASS_NONE) rc = sprintf(buf, "\n"); - else if (ndns->claim_class == NVDIMM_CCLASS_BTT) + else if ((ndns->claim_class == NVDIMM_CCLASS_BTT) || + (ndns->claim_class == NVDIMM_CCLASS_BTT2)) rc = sprintf(buf, "btt\n"); else if (ndns->claim_class == NVDIMM_CCLASS_PFN) rc = sprintf(buf, "pfn\n"); -- cgit v1.2.3