From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CE009C433E1 for ; Wed, 20 May 2020 15:32:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B10CA20708 for ; Wed, 20 May 2020 15:32:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726916AbgETPcO (ORCPT ); Wed, 20 May 2020 11:32:14 -0400 Received: from mga02.intel.com ([134.134.136.20]:54618 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726560AbgETPcN (ORCPT ); Wed, 20 May 2020 11:32:13 -0400 IronPort-SDR: in/Jz/atW3yH5gtagtL7YtmtTUOqCAEsgFWyKmKL19Y5Bu2myLtWvpu1e92VCdB6bfN80vIBlb Nq5E34dK1PYA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 May 2020 08:32:10 -0700 IronPort-SDR: L5OCpt1AW072WxXjmfjFfsyb+W25C/+dnDIbfKrp5BRYmePli9WX1odRFqEO5lRYZpcvJeciA5 gQZIv/8Urgpw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,414,1583222400"; d="scan'208";a="255049410" Received: from iweiny-desk2.sc.intel.com ([10.3.52.147]) by fmsmga008.fm.intel.com with ESMTP; 20 May 2020 08:32:10 -0700 Date: Wed, 20 May 2020 08:32:10 -0700 From: Ira Weiny To: Vaibhav Jain Cc: linuxppc-dev@lists.ozlabs.org, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, "Aneesh Kumar K . V" , Michael Ellerman , Steven Rostedt Subject: Re: [RESEND PATCH v7 4/5] ndctl/papr_scm,uapi: Add support for PAPR nvdimm specific methods Message-ID: <20200520153209.GC3660833@iweiny-DESK2.sc.intel.com> References: <20200519190058.257981-1-vaibhav@linux.ibm.com> <20200519190058.257981-5-vaibhav@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200519190058.257981-5-vaibhav@linux.ibm.com> User-Agent: Mutt/1.11.1 (2018-12-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 20, 2020 at 12:30:57AM +0530, Vaibhav Jain wrote: > Introduce support for Papr nvDimm Specific Methods (PDSM) in papr_scm > modules and add the command family to the white list of NVDIMM command > sets. Also advertise support for ND_CMD_CALL for the dimm > 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: Dan Williams > Cc: Michael Ellerman > Cc: "Aneesh Kumar K . V" > Signed-off-by: Vaibhav Jain > --- > Changelog: > > 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_scm_pdsm.h | 134 ++++++++++++++++++ > arch/powerpc/platforms/pseries/papr_scm.c | 101 ++++++++++++- > include/uapi/linux/ndctl.h | 1 + > 3 files changed, 230 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 000000000000..671693439c1c > --- /dev/null > +++ b/arch/powerpc/include/uapi/asm/papr_scm_pdsm.h > @@ -0,0 +1,134 @@ > +/* 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 > + * 'envelopes' 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 offset of which relative to the struct is provided > + * by 'nd_pdsm_cmd_pkg.payload_offset'. * > + * > + * +-------------+---------------------+---------------------------+ > + * | 64-Bytes | 8-Bytes | Max 184-Bytes | > + * +-------------+---------------------+---------------------------+ > + * | nd_pdsm_cmd_pkg | | > + * |-------------+ | | > + * | nd_cmd_pkg | | | > + * +-------------+---------------------+---------------------------+ > + * | nd_family | | | > + * | nd_size_out | cmd_status | | > + * | nd_size_in | payload_version | PAYLOAD | > + * | nd_command | payload_offset -----> | > + * | 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. > + * 'payload_version' : (In/Out) Version number associated with the payload. > + * 'payload_offset' : (In)Relative offset of payload from start of envelope. > + * > + * 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). > + * > + * Payload Version: > + * > + * A 'payload_version' field is present in PDSM header that indicates a specific > + * version of the structure present in PDSM Payload for a given PDSM command. > + * This provides backward compatibility in case the PDSM Payload structure > + * evolves and different structures are supported by 'papr_scm' and 'libndctl'. > + * > + * When sending a PDSM Payload to 'papr_scm', 'libndctl' should send the version > + * of the payload struct it supports via 'payload_version' field. The 'papr_scm' > + * module when servicing the PDSM envelope checks the 'payload_version' and then > + * uses 'payload struct version' == MIN('payload_version field', > + * 'max payload-struct-version supported by papr_scm') to service the PDSM. > + * After servicing the PDSM, 'papr_scm' put the negotiated version of payload > + * struct in returned 'payload_version' field. FWIW many people believe using a size rather than version is more sustainable. It is expected that new payload structures are larger (more features) than the previous payload structure. I can't find references at the moment through. What does payload_version provide us that the command size in/out does not? > + * > + * Libndctl on receiving the envelope back from papr_scm again checks the > + * 'payload_version' field and based on it use the appropriate version dsm > + * struct to parse the results. > + * > + * Backward Compatibility: > + * > + * Above scheme of exchanging different versioned PDSM struct between libndctl > + * and papr_scm should provide backward compatibility until following two > + * assumptions/conditions when defining new PDSM structs hold: > + * > + * Let T(X) = { set of attributes in PDSM struct 'T' versioned X } > + * > + * 1. T(X) is a proper subset of T(Y) if X > Y. Proper superset? Or Y > X? Ira > + * i.e Each new version of PDSM struct should retain existing struct > + * attributes from previous version > + * > + * 2. If an entity (libndctl or papr_scm) supports a PDSM struct T(X) then > + * it should also support T(1), T(2)...T(X - 1). > + * i.e When adding support for new version of a PDSM struct, libndctl > + * and papr_scm should retain support of the existing PDSM struct > + * version they support. > + */ > + > +/* Papr-scm-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 payload_offset; /* In: offset from start of struct */ > + __u16 payload_version; /* In/Out: version of the payload */ > + __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_scm_pdsm { > + PAPR_SCM_PDSM_MIN = 0x0, > + PAPR_SCM_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 *)((__u8 *) pcmd + pcmd->payload_offset); > +} > + > +#endif /* _UAPI_ASM_POWERPC_PAPR_SCM_PDSM_H_ */ > diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c > index 142636e1a59f..ed4b49a6f1e1 100644 > --- a/arch/powerpc/platforms/pseries/papr_scm.c > +++ b/arch/powerpc/platforms/pseries/papr_scm.c > @@ -15,13 +15,15 @@ > #include > > #include > +#include > > #define BIND_ANY_ADDR (~0ul) > > #define PAPR_SCM_DIMM_CMD_MASK \ > ((1ul << ND_CMD_GET_CONFIG_SIZE) | \ > (1ul << ND_CMD_GET_CONFIG_DATA) | \ > - (1ul << ND_CMD_SET_CONFIG_DATA)) > + (1ul << ND_CMD_SET_CONFIG_DATA) | \ > + (1ul << ND_CMD_CALL)) > > /* DIMM health bitmap bitmap indicators */ > /* SCM device is unable to persist memory contents */ > @@ -350,16 +352,97 @@ static int papr_scm_meta_set(struct papr_scm_priv *p, > return 0; > } > > +/* > + * Validate the inputs args to dimm-control function and return '0' if valid. > + * This also does initial sanity validation to ND_CMD_CALL sub-command packages. > + */ > +static int is_cmd_valid(struct nvdimm *nvdimm, unsigned int cmd, void *buf, > + unsigned int buf_len) > +{ > + unsigned long cmd_mask = PAPR_SCM_DIMM_CMD_MASK; > + struct nd_pdsm_cmd_pkg *pkg = nd_to_pdsm_cmd_pkg(buf); > + struct papr_scm_priv *p; > + > + /* Only dimm-specific calls are supported atm */ > + if (!nvdimm) > + return -EINVAL; > + > + /* get the provider date from struct nvdimm */ > + p = nvdimm_provider_data(nvdimm); > + > + if (!test_bit(cmd, &cmd_mask)) { > + dev_dbg(&p->pdev->dev, "Unsupported cmd=%u\n", cmd); > + return -EINVAL; > + } else if (cmd == ND_CMD_CALL) { > + > + /* Verify the envelope package */ > + if (!buf || buf_len < sizeof(struct nd_pdsm_cmd_pkg)) { > + dev_dbg(&p->pdev->dev, "Invalid pkg size=%u\n", > + buf_len); > + return -EINVAL; > + } > + > + /* Verify that the PDSM family is valid */ > + if (pkg->hdr.nd_family != NVDIMM_FAMILY_PAPR_SCM) { > + dev_dbg(&p->pdev->dev, "Invalid pkg family=0x%llx\n", > + pkg->hdr.nd_family); > + return -EINVAL; > + > + } > + > + /* We except a payload with all PDSM commands */ > + if (pdsm_cmd_to_payload(pkg) == NULL) { > + dev_dbg(&p->pdev->dev, > + "Empty payload for sub-command=0x%llx\n", > + pkg->hdr.nd_command); > + return -EINVAL; > + } > + } > + > + /* Command looks valid */ > + return 0; > +} > + > +static int papr_scm_service_pdsm(struct papr_scm_priv *p, > + struct nd_pdsm_cmd_pkg *call_pkg) > +{ > + /* unknown subcommands return error in packages */ > + if (call_pkg->hdr.nd_command <= PAPR_SCM_PDSM_MIN || > + call_pkg->hdr.nd_command >= PAPR_SCM_PDSM_MAX) { > + dev_dbg(&p->pdev->dev, "Invalid PDSM request 0x%llx\n", > + call_pkg->hdr.nd_command); > + call_pkg->cmd_status = -EINVAL; > + return 0; > + } > + > + /* Depending on the DSM command call appropriate service routine */ > + switch (call_pkg->hdr.nd_command) { > + default: > + dev_dbg(&p->pdev->dev, "Unsupported PDSM request 0x%llx\n", > + call_pkg->hdr.nd_command); > + call_pkg->cmd_status = -ENOENT; > + return 0; > + } > +} > + > static int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, > struct nvdimm *nvdimm, unsigned int cmd, void *buf, > unsigned int buf_len, int *cmd_rc) > { > struct nd_cmd_get_config_size *get_size_hdr; > struct papr_scm_priv *p; > + struct nd_pdsm_cmd_pkg *call_pkg = NULL; > + int rc; > > - /* Only dimm-specific calls are supported atm */ > - if (!nvdimm) > - return -EINVAL; > + /* Use a local variable in case cmd_rc pointer is NULL */ > + if (cmd_rc == NULL) > + cmd_rc = &rc; > + > + *cmd_rc = is_cmd_valid(nvdimm, cmd, buf, buf_len); > + if (*cmd_rc) { > + pr_debug("Invalid cmd=0x%x. Err=%d\n", cmd, *cmd_rc); > + return *cmd_rc; > + } > > p = nvdimm_provider_data(nvdimm); > > @@ -381,13 +464,19 @@ static int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, > *cmd_rc = papr_scm_meta_set(p, buf); > break; > > + case ND_CMD_CALL: > + call_pkg = nd_to_pdsm_cmd_pkg(buf); > + *cmd_rc = papr_scm_service_pdsm(p, call_pkg); > + break; > + > default: > - return -EINVAL; > + dev_dbg(&p->pdev->dev, "Unknown command = %d\n", cmd); > + *cmd_rc = -EINVAL; > } > > dev_dbg(&p->pdev->dev, "returned with cmd_rc = %d\n", *cmd_rc); > > - return 0; > + return *cmd_rc; > } > > static ssize_t flags_show(struct device *dev, > diff --git a/include/uapi/linux/ndctl.h b/include/uapi/linux/ndctl.h > index de5d90212409..99fb60600ef8 100644 > --- a/include/uapi/linux/ndctl.h > +++ b/include/uapi/linux/ndctl.h > @@ -244,6 +244,7 @@ struct nd_cmd_pkg { > #define NVDIMM_FAMILY_HPE2 2 > #define NVDIMM_FAMILY_MSFT 3 > #define NVDIMM_FAMILY_HYPERV 4 > +#define NVDIMM_FAMILY_PAPR_SCM 5 > > #define ND_IOCTL_CALL _IOWR(ND_IOCTL, ND_CMD_CALL,\ > struct nd_cmd_pkg) > -- > 2.26.2 > _______________________________________________ > Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org > To unsubscribe send an email to linux-nvdimm-leave@lists.01.org