kernel/linux.git/include/uapi/linux/ndctl.h, branch v6.12.80

treewide: uapi: Replace zero-length arrays with flexible-array members

2022-06-28T19:26:05+00:00

There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. This code was transformed with the help of Coccinelle: (linux-5.19-rc2$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file script.cocci --include-headers --dir . > output.patch) @@ identifier S, member, array; type T1, T2; @@ struct S { ... T1 member; T2 array[ - 0 ]; }; -fstrict-flex-arrays=3 is coming and we need to land these changes to prevent issues like these in the short future: ../fs/minix/dir.c:337:3: warning: 'strcpy' will always overflow; destination buffer has size 0, but the source string has length 2 (including NUL byte) [-Wfortify-source] strcpy(de3->name, "."); ^ Since these are all [0] to [] changes, the risk to UAPI is nearly zero. If this breaks anything, we can use a union with a new member name. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays Link: https://github.com/KSPP/linux/issues/78 Build-tested-by: kernel test robot Link: https://lore.kernel.org/lkml/62b675ec.wKX6AOZ6cbE71vtF%25lkp@intel.com/ Acked-by: Dan Williams # For ndctl.h Signed-off-by: Gustavo A. R. Silva

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

ACPI: NFIT: Define runtime firmware activation commands

2020-07-26T01:34:47+00:00

Platform reboots are expensive. Towards reducing downtime to apply firmware updates the Intel NVDIMM command definition is growing support for applying live firmware updates that only require temporarily suspending memory traffic instead of a full reboot. Follow-on commits add support for triggering firmware activation, this patch only defines the commands, adds probe support, and validates that they are blocked via the ioctl path. The ioctl-path block ensures that the OS is in charge since these commands have side effects only the OS can handle. Specifically firmware activation may cause the memory controller to be quiesced on the order of 100s of milliseconds. In that case Linux ensure the activation only takes place while the OS is in a suspend state. Link: https://pmem.io/documents/IntelOptanePMem_DSM_Interface-V2.0.pdf Cc: Vishal Verma Cc: Dave Jiang Cc: Ira Weiny Cc: "Rafael J. Wysocki" Cc: Len Brown Signed-off-by: Dan Williams Signed-off-by: Vishal Verma

libnvdimm: Validate command family indices

2020-07-26T01:34:47+00:00

The ND_CMD_CALL format allows for a general passthrough of passlisted commands targeting a given command set. However there is no validation of the family index relative to what the bus supports. - Update the NFIT bus implementation (the only one that supports ND_CMD_CALL passthrough) to also passlist the valid set of command family indices. - Update the generic __nd_ioctl() path to validate that field on behalf of all implementations. Fixes: 31eca76ba2fc ("nfit, libnvdimm: limited/whitelisted dimm command marshaling mechanism") Cc: Vishal Verma Cc: Dave Jiang Cc: Ira Weiny Cc: "Rafael J. Wysocki" Cc: Len Brown Cc: Signed-off-by: Dan Williams Signed-off-by: Vishal Verma

ndctl/papr_scm,uapi: Add support for PAPR nvdimm specific methods

2020-06-16T01:22:44+00:00

Introduce support for PAPR NVDIMM Specific Methods (PDSM) in papr_scm module and add the command family NVDIMM_FAMILY_PAPR to the white list of NVDIMM command sets. Also advertise support for ND_CMD_CALL for the nvdimm command mask and implement necessary scaffolding in the module to handle ND_CMD_CALL ioctl and PDSM requests that we receive. The layout of the PDSM request as we expect from libnvdimm/libndctl is described in newly introduced uapi header 'papr_pdsm.h' which defines a 'struct nd_pkg_pdsm' and a maximal union named 'nd_pdsm_payload'. These new structs together with 'struct nd_cmd_pkg' for a pdsm envelop thats sent by libndctl to libnvdimm and serviced by papr_scm in 'papr_scm_service_pdsm()'. The PDSM request is communicated by member 'struct nd_cmd_pkg.nd_command' together with other information on the pdsm payload (size-in, size-out). The patch also introduces 'struct pdsm_cmd_desc' instances of which are stored in an array __pdsm_cmd_descriptors[] indexed with PDSM cmd and corresponding access function pdsm_cmd_desc() is introduced. 'struct pdsm_cdm_desc' holds the service function for a given PDSM and corresponding payload in/out sizes. A new function papr_scm_service_pdsm() is introduced and is called from papr_scm_ndctl() in case of a PDSM request is received via ND_CMD_CALL command from libnvdimm. The function performs validation on the PDSM payload based on info present in corresponding PDSM descriptor and if valid calls the 'struct pdcm_cmd_desc.service' function to service the PDSM. Signed-off-by: Vaibhav Jain Cc: "Aneesh Kumar K . V" Cc: Dan Williams Cc: Michael Ellerman Cc: Ira Weiny Link: https://lore.kernel.org/r/20200615124407.32596-6-vaibhav@linux.ibm.com Signed-off-by: Dan Williams

nfit: Add Hyper-V NVDIMM DSM command set to white list

2019-01-30T06:09:31+00:00

Add the Hyper-V _DSM command set to the white list of NVDIMM command sets. This command set is documented at http://www.uefi.org/RFIC_LIST (see "Virtual NVDIMM 0x1901"). Signed-off-by: Dexuan Cui Reviewed-by: Michael Kelley Signed-off-by: Dan Williams

UAPI: ndctl: Remove use of PAGE_SIZE

2018-10-17T20:56:58+00:00

The macro PAGE_SIZE isn't valid outside of the kernel, so it should not appear in UAPI headers. Furthermore, the actual machine page size could theoretically change from an application's point of view if it's running in a container that gets migrated to another machine (say 4K/ppc64 to 64K/ppc64). Fixes: f2ba5a5baecf ("libnvdimm, namespace: make min namespace size 4K") Signed-off-by: David Howells Signed-off-by: Dan Williams

UAPI: ndctl: Fix g++-unsupported initialisation in headers

2018-10-17T20:56:54+00:00

The following code in the linux/ndctl header file: static inline const char *nvdimm_bus_cmd_name(unsigned cmd) { static const char * const names[] = { [ND_CMD_ARS_CAP] = "ars_cap", [ND_CMD_ARS_START] = "ars_start", [ND_CMD_ARS_STATUS] = "ars_status", [ND_CMD_CLEAR_ERROR] = "clear_error", [ND_CMD_CALL] = "cmd_call", }; if (cmd < ARRAY_SIZE(names) && names[cmd]) return names[cmd]; return "unknown"; } is broken in a number of ways: (1) ARRAY_SIZE() is not generally defined. (2) g++ does not support "non-trivial" array initialisers fully yet. (3) Every file that calls this function will acquire a copy of names[]. The same goes for nvdimm_cmd_name(). Fix all three by converting to a switch statement where each case returns a string. That way if cmd is a constant, the compiler can trivially reduce it and, if not, the compiler can use a shared lookup table if it thinks that is more efficient. A better way would be to remove these functions and their arrays from the header entirely. Signed-off-by: David Howells Signed-off-by: Dan Williams

libnvdimm, namespace: make min namespace size 4K

2018-02-02T05:27:22+00:00

The arbitrary 4MB minimum namespace size turns out to be too large for some environments. Quoting Cheng-mean Liu: In the case of emulated NVDIMM devices in the VM environment, there are scenarios that NVDIMM device with much smaller sizes are desired, for example, we might use a single enumerated NVDIMM DAX device for representing each container layer, which in some cases could be just a few KBs size. PAGE_SIZE is the minimum where we can still support DAX of at least a single page. Cc: Matthew Wilcox Reported-by: Cheng-mean Liu Signed-off-by: Dan Williams

nfit, libnvdimm: deprecate the generic SMART ioctl

2017-12-04T18:19:20+00:00

The kernel's ND_IOCTL_SMART_THRESHOLD command is based on a payload definition that has become broken / out-of-sync with recent versions of the NVDIMM_FAMILY_INTEL definition. Deprecate the use of the ND_IOCTL_SMART_THRESHOLD command in favor of the ND_CMD_CALL approach taken by NVDIMM_FAMILY_{HPE,MSFT}, where we can manage the per-vendor variance in userspace. In a couple years, when the new scheme is widely deployed in userspace packages, the ND_IOCTL_SMART_THRESHOLD support can be removed. For now we prevent new binaries from compiling against the kernel header definitions, but kernel still compatible with old binaries. The libndctl.h [1] header is now the authoritative interface definition for NVDIMM SMART. [1]: https://github.com/pmem/ndctl Signed-off-by: Dan Williams