Introduce support for PAPR NVDIMM Specific Methods (PDSM) in papr_scm
module and add the command family 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_scm_pdsm.h' which
defines a new 'struct nd_pdsm_cmd_pkg' header. This header is used
to communicate the PDSM request via member
'nd_pkg_papr_scm->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"
Cc: Dan Williams
Cc: Michael Ellerman
Cc: Ira Weiny
Signed-off-by: Vaibhav Jain
---
Changelog:
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 0x1 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_scm_pdsm.h | 136 ++
arch/powerpc/platforms/pseries/papr_scm.c | 101 -
include/uapi/linux/ndctl.h| 1 +
3 files changed, 232 insertions(+), 6 deletions(-)
create mode 100644 arch/powerpc/include/uapi/asm/papr_scm_pdsm.h
diff --git a/arch/powerpc/include/uapi/asm/papr_scm_pdsm.h
b/arch/powerpc/include/uapi/asm/papr_scm_pdsm.h
new file mode 100644
index ..c4bae3208e73
--- /dev/null
+++ b/arch/powerpc/include/uapi/asm/papr_scm_pdsm.h
@@ -0,0 +1,136 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * PAPR-SCM Dimm specific methods (PDSM) and structs for libndctl
+ *
+ * (C) Copyright IBM 2020
+ *
+ * Author: Vaibhav Jain
+ */
+
+#ifndef _UAPI_ASM_POWERPC_PAPR_SCM_PDSM_H_
+#define _UAPI_ASM_POWERPC_PAPR_SCM_PDSM_H_
+
+#include
+
+/*
+ * 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 | 16-Bytes | Max 176-Bytes |
+ * +-+-+---+
+ * | nd_pdsm_cmd_pkg | |
+ * |-+ | |
+ * | nd_cmd_pkg | | |
+ * +-+-+---+
+ * | nd_family | | |
+ * | nd_size_out | cmd_status | |
+ * | nd_size_in | payload_version | payload |
+ * | nd_command | reserved| |
+ * | nd_fw_size | | |
+ *
