kernel/linux.git/drivers/nvdimm/label.c, branch v6.12.98

libnvdimm/labels: Fix divide error in nd_label_data_init()

2025-05-29T09:02:09+00:00

[ Upstream commit ef1d3455bbc1922f94a91ed58d3d7db440652959 ] If a faulty CXL memory device returns a broken zero LSA size in its memory device information (Identify Memory Device (Opcode 4000h), CXL spec. 3.1, 8.2.9.9.1.1), a divide error occurs in the libnvdimm driver: Oops: divide error: 0000 [#1] PREEMPT SMP NOPTI RIP: 0010:nd_label_data_init+0x10e/0x800 [libnvdimm] Code and flow: 1) CXL Command 4000h returns LSA size = 0 2) config_size is assigned to zero LSA size (CXL pmem driver): drivers/cxl/pmem.c: .config_size = mds->lsa_size, 3) max_xfer is set to zero (nvdimm driver): drivers/nvdimm/label.c: max_xfer = min_t(size_t, ndd->nsarea.max_xfer, config_size); 4) A subsequent DIV_ROUND_UP() causes a division by zero: drivers/nvdimm/label.c: /* Make our initial read size a multiple of max_xfer size */ drivers/nvdimm/label.c: read_size = min(DIV_ROUND_UP(read_size, max_xfer) * max_xfer, drivers/nvdimm/label.c- config_size); Fix this by checking the config size parameter by extending an existing check. Signed-off-by: Robert Richter Reviewed-by: Pankaj Gupta Reviewed-by: Ira Weiny Link: https://patch.msgid.link/20250320112223.608320-1-rrichter@amd.com Signed-off-by: Ira Weiny Signed-off-by: Sasha Levin

nvdimm/region: Delete nd_blk_region infrastructure

2022-03-11T23:53:13+00:00

Now that the nd_namespace_blk infrastructure is removed, delete all the region machinery to coordinate provisioning aliased capacity between PMEM and BLK. Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/164688418803.2879318.1302315202397235855.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams

nvdimm/namespace: Delete nd_namespace_blk

2022-03-11T23:53:12+00:00

Now that none of the configuration paths consider BLK namespaces, delete the BLK namespace data and supporting code. Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/164688417727.2879318.11691110761800109662.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams

libnvdimm/labels: Introduce CXL labels

2021-09-21T20:44:56+00:00

Now that all of use sites of label data have been converted to nsl_* helpers, introduce the CXL label format. The ->cxl flag in nvdimm_drvdata indicates the label format the device expects. A follow-on patch allows a bus provider to select the label style. Note that the EFI definition of the labels represents the Linux "claim class" with a GUID. The CXL definition of the labels stores the same identifier in UUID byte order. Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/163116432405.2460985.5547867384570123403.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams

libnvdimm/labels: Introduce the concept of multi-range namespace labels

2021-09-21T20:44:55+00:00

The CXL specification defines a mechanism for namespaces to be comprised of multiple dis-contiguous ranges. Introduce that concept to the legacy NVDIMM namespace implementation with a new nsl_set_nrange() helper, that sets the number of ranges to 1. Once the NVDIMM subsystem supports CXL labels and updates its namespace capacity provisioning for dis-contiguous support nsl_set_nrange() can be updated, but in the meantime CXL label validation requires nrange be non-zero. Reported-by: Jonathan Cameron Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/163116430804.2460985.5482188351381597529.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams

libnvdimm/labels: Add uuid helpers

2021-09-21T20:44:55+00:00

In preparation for CXL labels that move the uuid to a different offset in the label, add nsl_{ref,get,validate}_uuid(). These helpers use the proper uuid_t type. That type definition predated the libnvdimm subsystem, so now is as a good a time as any to convert all the uuid handling in the subsystem to uuid_t to match the helpers. Note that the uuid fields in the label data and superblocks is not replaced per Andy's expectation that uuid_t is a kernel internal type not to appear in external ABI interfaces. So, in those case {import,export}_uuid() is used to go between the 2 types. Also note that this rework uncovered some unnecessary copies for label comparisons, those are cleaned up with nsl_uuid_equal(). As for the whitespace changes, all new code is clang-format compliant. Reported-by: Andy Shevchenko Reviewed-by: Andy Shevchenko Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/163116429748.2460985.15659993454313919977.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams

libnvdimm/labels: Add claim class helpers

2021-08-24T19:08:28+00:00

In preparation for LIBNVDIMM to manage labels on CXL devices deploy helpers that abstract the label type from the implementation. The CXL label format is mostly similar to the EFI label format with concepts / fields added, like dynamic region creation and label type guids, and other concepts removed like BLK-mode and interleave-set-cookie ids. CXL labels do have the concept of a claim class represented by an "abstraction" identifier. It turns out both label implementations use the same ids, but EFI encodes them as GUIDs and CXL labels encode them as UUIDs. For now abstract out the claim class such that the UUID vs GUID distinction can later be hidden in the helper. Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/162982116719.1124374.9917866609080940364.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams

libnvdimm/labels: Add type-guid helpers

2021-08-24T19:08:28+00:00

In preparation for CXL label support, which does not have the type-guid concept, wrap the existing users with nsl_set_type_guid, and nsl_validate_type_guid. Recall that the type-guid is a value in the ACPI NFIT table to indicate how the memory range is used / should be presented to upper layers. Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/162982116208.1124374.13938280892226800953.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams

libnvdimm/labels: Add blk special cases for nlabel and position helpers

2021-08-24T19:08:28+00:00

In preparation for LIBNVDIMM to manage labels on CXL devices deploy helpers that abstract the label type from the implementation. The CXL label format is mostly similar to the EFI label format with concepts / fields added, like dynamic region creation and label type guids, and other concepts removed like BLK-mode and interleave-set-cookie ids. Finish off the BLK-mode specific helper conversion with the nlabel and position behaviour that is specific to EFI v1.2 labels and not the original v1.1 definition. Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/162982115698.1124374.10182273478536799613.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams

libnvdimm/labels: Add blk isetcookie set / validation helpers

2021-08-24T19:08:28+00:00

In preparation for LIBNVDIMM to manage labels on CXL devices deploy helpers that abstract the label type from the implementation. The CXL label format is mostly similar to the EFI label format with concepts / fields added, like dynamic region creation and label type guids, and other concepts removed like BLK-mode and interleave-set-cookie ids. Given BLK-mode is not even supported on CXL push hide the BLK-mode specific details inside the helpers. Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/162982115185.1124374.13459190993792729776.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams