Messages in this thread | | | From | Dan Williams <> | Date | Fri, 5 Jun 2020 13:58:11 -0700 | Subject | Re: [PATCH v10 5/6] ndctl/papr_scm,uapi: Add support for PAPR nvdimm specific methods |
| |
On Fri, Jun 5, 2020 at 12:50 PM Ira Weiny <ira.weiny@intel.com> wrote: > > On Fri, Jun 05, 2020 at 05:11:35AM +0530, Vaibhav Jain wrote: > > 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 new 'struct nd_pdsm_cmd_pkg' header. This header is used > > to communicate the PDSM request via member > > 'nd_cmd_pkg.nd_command' and size of payload that need to be > > sent/received for servicing the PDSM. > > > > A new function is_cmd_valid() is implemented that reads the args to > > papr_scm_ndctl() and performs sanity tests on them. 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. > > > > Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com> > > Cc: Dan Williams <dan.j.williams@intel.com> > > Cc: Michael Ellerman <mpe@ellerman.id.au> > > Cc: Ira Weiny <ira.weiny@intel.com> > > Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> > > --- > > Changelog: > > > > v9..v10: > > * Simplified 'struct nd_pdsm_cmd_pkg' by removing the > > 'payload_version' field. > > * Removed the corrosponding documentation on versioning and backward > > compatibility from 'papr_pdsm.h' > > * Reduced the size of reserved fields to 4-bytes making 'struct > > nd_pdsm_cmd_pkg' 64 + 8 bytes long. > > * Updated is_cmd_valid() to enforce validation checks on pdsm > > commands. [ Dan Williams ] > > * Added check for reserved fields being set to '0' in is_cmd_valid() > > [ Ira ] > > * Moved changes for checking cmd_rc == NULL and logging improvements > > to a separate prelim patch [ Ira ]. > > * Moved pdsm package validation checks from papr_scm_service_pdsm() > > to is_cmd_valid(). > > * Marked papr_scm_service_pdsm() return type as 'void' since errors > > are reported in nd_pdsm_cmd_pkg.cmd_status field. > > > > Resend: > > * Added ack from Aneesh. > > > > v8..v9: > > * Reduced the usage of term SCM replacing it with appropriate > > replacement [ Dan Williams, Aneesh ] > > * Renamed 'papr_scm_pdsm.h' to 'papr_pdsm.h' > > * s/PAPR_SCM_PDSM_*/PAPR_PDSM_*/g > > * s/NVDIMM_FAMILY_PAPR_SCM/NVDIMM_FAMILY_PAPR/g > > * Minor updates to 'papr_psdm.h' to replace usage of term 'SCM'. > > * Minor update to patch description. > > > > v7..v8: > > * Removed the 'payload_offset' field from 'struct > > nd_pdsm_cmd_pkg'. Instead command payload is always assumed to start > > at 'nd_pdsm_cmd_pkg.payload'. [ Aneesh ] > > * To enable introducing new fields to 'struct nd_pdsm_cmd_pkg', > > 'reserved' field of 10-bytes is introduced. [ Aneesh ] > > * Fixed a typo in "Backward Compatibility" section of papr_scm_pdsm.h > > [ Ira ] > > > > Resend: > > * None > > > > v6..v7 : > > * Removed the re-definitions of __packed macro from papr_scm_pdsm.h > > [Mpe]. > > * Removed the usage of __KERNEL__ macros in papr_scm_pdsm.h [Mpe]. > > * Removed macros that were unused in papr_scm.c from papr_scm_pdsm.h > > [Mpe]. > > * Made functions defined in papr_scm_pdsm.h as static inline. [Mpe] > > > > v5..v6 : > > * Changed the usage of the term DSM to PDSM to distinguish it from the > > ACPI term [ Dan Williams ] > > * Renamed papr_scm_dsm.h to papr_scm_pdsm.h and updated various struct > > to reflect the new terminology. > > * Updated the patch description and title to reflect the new terminology. > > * Squashed patch to introduce new command family in 'ndctl.h' with > > this patch [ Dan Williams ] > > * Updated the papr_scm_pdsm method starting index from 0x10000 to 0x0 > > [ Dan Williams ] > > * Removed redundant license text from the papr_scm_psdm.h file. > > [ Dan Williams ] > > * s/envelop/envelope/ at various places [ Dan Williams ] > > * Added '__packed' attribute to command package header to gaurd > > against different compiler adding paddings between the fields. > > [ Dan Williams] > > * Converted various pr_debug to dev_debug [ Dan Williams ] > > > > v4..v5 : > > * None > > > > v3..v4 : > > * None > > > > v2..v3 : > > * Updated the patch prefix to 'ndctl/uapi' [Aneesh] > > > > v1..v2 : > > * None > > --- > > arch/powerpc/include/uapi/asm/papr_pdsm.h | 98 +++++++++++++++++++ > > arch/powerpc/platforms/pseries/papr_scm.c | 113 +++++++++++++++++++++- > > include/uapi/linux/ndctl.h | 1 + > > 3 files changed, 207 insertions(+), 5 deletions(-) > > create mode 100644 arch/powerpc/include/uapi/asm/papr_pdsm.h > > > > diff --git a/arch/powerpc/include/uapi/asm/papr_pdsm.h b/arch/powerpc/include/uapi/asm/papr_pdsm.h > > new file mode 100644 > > index 000000000000..8b1a4f8fa316 > > --- /dev/null > > +++ b/arch/powerpc/include/uapi/asm/papr_pdsm.h > > @@ -0,0 +1,98 @@ > > +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ > > +/* > > + * PAPR nvDimm Specific Methods (PDSM) and structs for libndctl > > + * > > + * (C) Copyright IBM 2020 > > + * > > + * Author: Vaibhav Jain <vaibhav at linux.ibm.com> > > + */ > > + > > +#ifndef _UAPI_ASM_POWERPC_PAPR_PDSM_H_ > > +#define _UAPI_ASM_POWERPC_PAPR_PDSM_H_ > > + > > +#include <linux/types.h> > > + > > +/* > > + * PDSM Envelope: > > + * > > + * The ioctl ND_CMD_CALL transfers data between user-space and kernel via > > + * envelope which consists of a header and user-defined payload sections. > > + * The header is described by 'struct nd_pdsm_cmd_pkg' which expects a > > + * payload following it and accessible via 'nd_pdsm_cmd_pkg.payload' field. > > + * There is reserved field that can used to introduce new fields to the > > + * structure in future. It also tries to ensure that 'nd_pdsm_cmd_pkg.payload' > > + * lies at a 8-byte boundary. > > + * > > + * +-------------+---------------------+---------------------------+ > > + * | 64-Bytes | 8-Bytes | Max 184-Bytes | > > + * +-------------+---------------------+---------------------------+ > > + * | nd_pdsm_cmd_pkg | | > > + * |-------------+ | | > > + * | nd_cmd_pkg | | | > > + * +-------------+---------------------+---------------------------+ > > + * | nd_family | | | > > + * | nd_size_out | cmd_status | | > > + * | nd_size_in | reserved | payload | > > + * | nd_command | | | > > + * | nd_fw_size | | | > > + * +-------------+---------------------+---------------------------+ > > + * > > + * PDSM Header: > > + * > > + * The header is defined as 'struct nd_pdsm_cmd_pkg' which embeds a > > + * 'struct nd_cmd_pkg' instance. The PDSM command is assigned to member > > + * 'nd_cmd_pkg.nd_command'. Apart from size information of the envelope which is > > + * contained in 'struct nd_cmd_pkg', the header also has members following > > + * members: > > + * > > + * 'cmd_status' : (Out) Errors if any encountered while servicing PDSM. > > + * 'reserved' : Not used, reserved for future and should be set to 0. > > + * > > + * PDSM Payload: > > + * > > + * The layout of the PDSM Payload is defined by various structs shared between > > + * papr_scm and libndctl so that contents of payload can be interpreted. During > > + * servicing of a PDSM the papr_scm module will read input args from the payload > > + * field by casting its contents to an appropriate struct pointer based on the > > + * PDSM command. Similarly the output of servicing the PDSM command will be > > + * copied to the payload field using the same struct. > > + * > > + * 'libnvdimm' enforces a hard limit of 256 bytes on the envelope size, which > > + * leaves around 184 bytes for the envelope payload (ignoring any padding that > > + * the compiler may silently introduce). > > + * > > + */ > > + > > +/* PDSM-header + payload expected with ND_CMD_CALL ioctl from libnvdimm */ > > +struct nd_pdsm_cmd_pkg { > > + struct nd_cmd_pkg hdr; /* Package header containing sub-cmd */ > > + __s32 cmd_status; /* Out: Sub-cmd status returned back */ > > + __u16 reserved[2]; /* Ignored and to be used in future */ > > + __u8 payload[]; /* In/Out: Sub-cmd data buffer */ > > +} __packed; > > + > > +/* > > + * Methods to be embedded in ND_CMD_CALL request. These are sent to the kernel > > + * via 'nd_pdsm_cmd_pkg.hdr.nd_command' member of the ioctl struct > > + */ > > +enum papr_pdsm { > > + PAPR_PDSM_MIN = 0x0, > > + PAPR_PDSM_MAX, > > +}; > > + > > +/* Convert a libnvdimm nd_cmd_pkg to pdsm specific pkg */ > > +static inline struct nd_pdsm_cmd_pkg *nd_to_pdsm_cmd_pkg(struct nd_cmd_pkg *cmd) > > +{ > > + return (struct nd_pdsm_cmd_pkg *)cmd; > > +} > > + > > +/* Return the payload pointer for a given pcmd */ > > +static inline void *pdsm_cmd_to_payload(struct nd_pdsm_cmd_pkg *pcmd) > > +{ > > + if (pcmd->hdr.nd_size_in == 0 && pcmd->hdr.nd_size_out == 0) > > + return NULL; > > + else > > + return (void *)(pcmd->payload); > > +} > > I just realized these were in the uapi header. You don't want to do this as > this code gets built into any user space program that uses it and there may be > license issues if the user space code is not a compatible license.
Yes, include/uapi/linux/ndctl.h is specifically LGPL for this reason.
| |