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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 31 Mar 2020 15:32:47 +0100 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 02VEWqFN52625452 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 31 Mar 2020 14:32:52 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 59354A405D; Tue, 31 Mar 2020 14:32:52 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B4088A4040; Tue, 31 Mar 2020 14:32:49 +0000 (GMT) Received: from vajain21.in.ibm.com.com (unknown [9.85.86.229]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 31 Mar 2020 14:32:49 +0000 (GMT) From: Vaibhav Jain To: linuxppc-dev@lists.ozlabs.org, linux-nvdimm@lists.01.org Subject: [PATCH v5 3/4] powerpc/papr_scm,uapi: Add support for handling PAPR DSM commands Date: Tue, 31 Mar 2020 20:02:28 +0530 X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200331143229.306718-1-vaibhav@linux.ibm.com> References: <20200331143229.306718-1-vaibhav@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 20033114-0012-0000-0000-0000039BAAB4 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20033114-0013-0000-0000-000021D8B71C Message-Id: <20200331143229.306718-4-vaibhav@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.676 definitions=2020-03-31_04:2020-03-31,2020-03-31 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 impostorscore=0 mlxscore=0 malwarescore=0 clxscore=1015 adultscore=0 bulkscore=0 mlxlogscore=999 priorityscore=1501 phishscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2003310125 Message-ID-Hash: MHLDWSEJHQ2GXRL2Z4IOTXG3Q23ZY4CN X-Message-ID-Hash: MHLDWSEJHQ2GXRL2Z4IOTXG3Q23ZY4CN X-MailFrom: vaibhav@linux.ibm.com X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation CC: Vaibhav Jain , "Aneesh Kumar K . V" , Michael Ellerman , Alastair D'Silva X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Implement support for handling PAPR DSM commands in papr_scm module. We 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 DSM commands that we receive. The layout of the DSM commands as we expect from libnvdimm/libndctl is described in newly introduced uapi header 'papr_scm_dsm.h' which defines a new 'struct nd_papr_scm_cmd_pkg' header. This header is used to communicate the DSM command via 'nd_pkg_papr_scm->nd_command' and size of payload that need to be sent/received for servicing the DSM. The PAPR DSM commands are assigned indexes started from 0x10000 to prevent them from overlapping ND_CMD_* values and also makes handling dimm commands in papr_scm_ndctl(). A new function cmd_to_func() is implemented that reads the args to papr_scm_ndctl() and performs sanity tests on them. In case of a DSM command being sent via ND_CMD_CALL a newly introduced function papr_scm_service_dsm() is called to handle the request. Signed-off-by: Vaibhav Jain Reviewed-by: Aneesh Kumar K.V --- Changelog: v4..v5: Fixed a bug in new implementation of papr_scm_ndctl(). v3..v4: Updated papr_scm_ndctl() to delegate DSM command handling to a different function papr_scm_service_dsm(). [Aneesh] v2..v3: Updated the nd_papr_scm_cmd_pkg to use __xx types as its exported to the userspace [Aneesh] v1..v2: New patch in the series. --- arch/powerpc/include/uapi/asm/papr_scm_dsm.h | 161 +++++++++++++++++++ arch/powerpc/platforms/pseries/papr_scm.c | 97 ++++++++++- 2 files changed, 252 insertions(+), 6 deletions(-) create mode 100644 arch/powerpc/include/uapi/asm/papr_scm_dsm.h diff --git a/arch/powerpc/include/uapi/asm/papr_scm_dsm.h b/arch/powerpc/include/uapi/asm/papr_scm_dsm.h new file mode 100644 index 000000000000..c039a49b41b4 --- /dev/null +++ b/arch/powerpc/include/uapi/asm/papr_scm_dsm.h @@ -0,0 +1,161 @@ +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ +/* + * PAPR SCM Device specific methods and struct for libndctl and ndctl + * + * (C) Copyright IBM 2020 + * + * Author: Vaibhav Jain + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef _UAPI_ASM_POWERPC_PAPR_SCM_DSM_H_ +#define _UAPI_ASM_POWERPC_PAPR_SCM_DSM_H_ + +#include + +#ifdef __KERNEL__ +#include +#else +#include +#endif + +/* + * DSM 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_papr_scm_cmd_pkg' which expects a + * payload following it and offset of which relative to the struct is provided + * by 'nd_papr_scm_cmd_pkg.payload_offset'. * + * + * +-------------+---------------------+---------------------------+ + * | 64-Bytes | 8-Bytes | Max 184-Bytes | + * +-------------+---------------------+---------------------------+ + * | nd_papr_scm_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 | | | + * +-------------+---------------------+---------------------------+ + * + * DSM Header: + * + * The header is defined as 'struct nd_papr_scm_cmd_pkg' which embeds a + * 'struct nd_cmd_pkg' instance. The DSM command is assigned to member + * 'nd_cmd_pkg.nd_command'. Apart from size information of the envelop which is + * contained in 'struct nd_cmd_pkg', the header also has members following + * members: + * + * 'cmd_status' : (Out) Errors if any encountered while servicing DSM. + * 'payload_version' : (In/Out) Version number associated with the payload. + * 'payload_offset' : (In)Relative offset of payload from start of envelope. + * + * DSM Payload: + * + * The layout of the DSM Payload is defined by various structs shared between + * papr_scm and libndctl so that contents of payload can be interpreted. During + * servicing of a DSM the papr_scm module will read input args from the payload + * field by casting its contents to an appropriate struct pointer based on the + * DSM command. Similarly the output of servicing the DSM 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 DSM header that indicates a specific + * version of the structure present in DSM Payload for a given DSM command. This + * provides backward compatibility in case the DSM Payload structure evolves + * and different structures are supported by 'papr_scm' and 'libndctl'. + * + * When sending a DSM 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 DSM envelop 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 DSM. After + * servicing the DSM, 'papr_scm' put the negotiated version of payload struct in + * returned 'payload_version' field. + * + * Libndctl on receiving the envelop 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 DSM struct between libndctl + * and papr_scm should provide backward compatibility until following two + * assumptions/conditions when defining new DSM structs hold: + * + * Let T(X) = { set of attributes in DSM struct 'T' versioned X } + * + * 1. T(X) is a proper subset of T(Y) if X > Y. + * i.e Each new version of DSM struct should retain existing struct + * attributes from previous version + * + * 2. If an entity (libndctl or papr_scm) supports a DSM 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 DSM struct, libndctl + * and papr_scm should retain support of the existing DSM struct + * version they support. + */ + +/* Papr-scm-header + payload expected with ND_CMD_CALL ioctl from libnvdimm */ +struct nd_papr_scm_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 */ +}; + +/* + * Sub commands for ND_CMD_CALL. To prevent overlap from ND_CMD_*, values for + * these enums start at 0x10000. These values are then returned from + * cmd_to_func() making it easy to implement the switch-case block in + * papr_scm_ndctl(). These commands are sent to the kernel via + * 'nd_papr_scm_cmd_pkg.hdr.nd_command' + */ +enum dsm_papr_scm { + DSM_PAPR_SCM_MIN = 0x10000, + DSM_PAPR_SCM_MAX, +}; + +/* Helpers to evaluate the size of PAPR_SCM envelope */ +/* Calculate the papr_scm-header size */ +#define ND_PAPR_SCM_ENVELOPE_CONTENT_HDR_SIZE \ + (sizeof(struct nd_papr_scm_cmd_pkg) - sizeof(struct nd_cmd_pkg)) + +/* Given a type calculate envelope-content size (papr_scm-header + payload) */ +#define ND_PAPR_SCM_ENVELOPE_CONTENT_SIZE(_type_) \ + (sizeof(_type_) + ND_PAPR_SCM_ENVELOPE_CONTENT_HDR_SIZE) + +/* Convert a libnvdimm nd_cmd_pkg to papr_scm specific pkg */ +static struct nd_papr_scm_cmd_pkg *nd_to_papr_cmd_pkg(struct nd_cmd_pkg *cmd) +{ + return (struct nd_papr_scm_cmd_pkg *) cmd; +} + +/* Return the payload pointer for a given pcmd */ +static void *papr_scm_pcmd_to_payload(struct nd_papr_scm_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_DSM_H_ */ diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c index aaf2e4ab1f75..e8ce96d2249e 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)) struct papr_scm_priv { struct platform_device *pdev; @@ -283,15 +285,92 @@ 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_papr_scm_cmd_pkg *pkg = nd_to_papr_cmd_pkg(buf); + + /* Only dimm-specific calls are supported atm */ + if (!nvdimm) + return -EINVAL; + + if (!test_bit(cmd, &cmd_mask)) { + pr_debug("%s: Unsupported cmd=%u\n", __func__, cmd); + return -EINVAL; + } else if (cmd == ND_CMD_CALL) { + + /* Verify the envelop package */ + if (!buf || buf_len < sizeof(struct nd_papr_scm_cmd_pkg)) { + pr_debug("%s: Invalid pkg size=%u\n", __func__, + buf_len); + return -EINVAL; + } + + /* Verify that the DSM command family is valid */ + if (pkg->hdr.nd_family != NVDIMM_FAMILY_PAPR_SCM) { + pr_debug("%s: Invalid pkg family=0x%llx\n", __func__, + pkg->hdr.nd_family); + return -EINVAL; + + } + + /* We except a payload with all DSM commands */ + if (papr_scm_pcmd_to_payload(pkg) == NULL) { + pr_debug("%s: Empty payload for sub-command=0x%llx\n", + __func__, pkg->hdr.nd_command); + return -EINVAL; + } + } + + /* Command looks valid */ + return 0; +} + +static int papr_scm_service_dsm(struct papr_scm_priv *p, + struct nd_papr_scm_cmd_pkg *call_pkg) +{ + /* unknown subcommands return error in packages */ + if (call_pkg->hdr.nd_command <= DSM_PAPR_SCM_MIN || + call_pkg->hdr.nd_command >= DSM_PAPR_SCM_MAX) { + pr_debug("Invalid DSM command 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: + pr_debug("Unsupported DSM command 0x%llx\n", + call_pkg->hdr.nd_command); + call_pkg->cmd_status = -ENOENT; + return 0; + } +} + 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_papr_scm_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("%s: Invalid cmd=0x%x. Err=%d\n", __func__, + cmd, *cmd_rc); + return *cmd_rc; + } p = nvdimm_provider_data(nvdimm); @@ -313,13 +392,19 @@ int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm, *cmd_rc = papr_scm_meta_set(p, buf); break; + case ND_CMD_CALL: + call_pkg = nd_to_papr_cmd_pkg(buf); + *cmd_rc = papr_scm_service_dsm(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 inline int papr_scm_node(int node)