Commit f517f792 authored by Vaibhav Jain's avatar Vaibhav Jain Committed by Dan Williams

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

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: default avatarVaibhav Jain <vaibhav@linux.ibm.com>
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>
Link: https://lore.kernel.org/r/20200615124407.32596-6-vaibhav@linux.ibm.comSigned-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent b5f38f09
/* 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>
#include <linux/ndctl.h>
/*
* PDSM Envelope:
*
* The ioctl ND_CMD_CALL exchange data between user-space and kernel via
* envelope which consists of 2 headers sections and payload sections as
* illustrated below:
* +-----------------+---------------+---------------------------+
* | 64-Bytes | 8-Bytes | Max 184-Bytes |
* +-----------------+---------------+---------------------------+
* | ND-HEADER | PDSM-HEADER | PDSM-PAYLOAD |
* +-----------------+---------------+---------------------------+
* | nd_family | | |
* | nd_size_out | cmd_status | |
* | nd_size_in | reserved | nd_pdsm_payload |
* | nd_command | payload --> | |
* | nd_fw_size | | |
* | nd_payload ---> | | |
* +---------------+-----------------+---------------------------+
*
* ND Header:
* This is the generic libnvdimm header described as 'struct nd_cmd_pkg'
* which is interpreted by libnvdimm before passed on to papr_scm. Important
* member fields used are:
* 'nd_family' : (In) NVDIMM_FAMILY_PAPR_SCM
* 'nd_size_in' : (In) PDSM-HEADER + PDSM-IN-PAYLOAD (usually 0)
* 'nd_size_out' : (In) PDSM-HEADER + PDSM-RETURN-PAYLOAD
* 'nd_command' : (In) One of PAPR_PDSM_XXX
* 'nd_fw_size' : (Out) PDSM-HEADER + size of actual payload returned
*
* PDSM Header:
* This is papr-scm specific header that precedes the payload. This is defined
* as nd_cmd_pdsm_pkg. Following fields aare available in this header:
*
* 'cmd_status' : (Out) Errors if any encountered while servicing PDSM.
* 'reserved' : Not used, reserved for future and should be set to 0.
* 'payload' : A union of all the possible payload structs
*
* 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. As such
* its defined as a union of all possible payload structs as
* 'union nd_pdsm_payload'. Based on the value of 'nd_cmd_pkg.nd_command'
* appropriate member of the union is accessed.
*/
/* Max payload size that we can handle */
#define ND_PDSM_PAYLOAD_MAX_SIZE 184
/* Max payload size that we can handle */
#define ND_PDSM_HDR_SIZE \
(sizeof(struct nd_pkg_pdsm) - ND_PDSM_PAYLOAD_MAX_SIZE)
/*
* Methods to be embedded in ND_CMD_CALL request. These are sent to the kernel
* via 'nd_cmd_pkg.nd_command' member of the ioctl struct
*/
enum papr_pdsm {
PAPR_PDSM_MIN = 0x0,
PAPR_PDSM_MAX,
};
/* Maximal union that can hold all possible payload types */
union nd_pdsm_payload {
__u8 buf[ND_PDSM_PAYLOAD_MAX_SIZE];
} __packed;
/*
* PDSM-header + payload expected with ND_CMD_CALL ioctl from libnvdimm
* Valid member of union 'payload' is identified via 'nd_cmd_pkg.nd_command'
* that should always precede this struct when sent to papr_scm via CMD_CALL
* interface.
*/
struct nd_pkg_pdsm {
__s32 cmd_status; /* Out: Sub-cmd status returned back */
__u16 reserved[2]; /* Ignored and to be set as '0' */
union nd_pdsm_payload payload;
} __packed;
#endif /* _UAPI_ASM_POWERPC_PAPR_PDSM_H_ */
...@@ -15,13 +15,15 @@ ...@@ -15,13 +15,15 @@
#include <linux/seq_buf.h> #include <linux/seq_buf.h>
#include <asm/plpar_wrappers.h> #include <asm/plpar_wrappers.h>
#include <asm/papr_pdsm.h>
#define BIND_ANY_ADDR (~0ul) #define BIND_ANY_ADDR (~0ul)
#define PAPR_SCM_DIMM_CMD_MASK \ #define PAPR_SCM_DIMM_CMD_MASK \
((1ul << ND_CMD_GET_CONFIG_SIZE) | \ ((1ul << ND_CMD_GET_CONFIG_SIZE) | \
(1ul << ND_CMD_GET_CONFIG_DATA) | \ (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 */ /* DIMM health bitmap bitmap indicators */
/* SCM device is unable to persist memory contents */ /* SCM device is unable to persist memory contents */
...@@ -349,17 +351,195 @@ static int papr_scm_meta_set(struct papr_scm_priv *p, ...@@ -349,17 +351,195 @@ static int papr_scm_meta_set(struct papr_scm_priv *p,
return 0; return 0;
} }
/*
* Do a sanity checks on the inputs args to dimm-control function and return
* '0' if valid. Validation of PDSM payloads happens later in
* papr_scm_service_pdsm.
*/
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_cmd_pkg *nd_cmd;
struct papr_scm_priv *p;
enum papr_pdsm pdsm;
/* Only dimm-specific calls are supported atm */
if (!nvdimm)
return -EINVAL;
/* get the provider data 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;
}
/* For CMD_CALL verify pdsm request */
if (cmd == ND_CMD_CALL) {
/* Verify the envelope and envelop size */
if (!buf ||
buf_len < (sizeof(struct nd_cmd_pkg) + ND_PDSM_HDR_SIZE)) {
dev_dbg(&p->pdev->dev, "Invalid pkg size=%u\n",
buf_len);
return -EINVAL;
}
/* Verify that the nd_cmd_pkg.nd_family is correct */
nd_cmd = (struct nd_cmd_pkg *)buf;
if (nd_cmd->nd_family != NVDIMM_FAMILY_PAPR) {
dev_dbg(&p->pdev->dev, "Invalid pkg family=0x%llx\n",
nd_cmd->nd_family);
return -EINVAL;
}
pdsm = (enum papr_pdsm)nd_cmd->nd_command;
/* Verify if the pdsm command is valid */
if (pdsm <= PAPR_PDSM_MIN || pdsm >= PAPR_PDSM_MAX) {
dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid PDSM\n",
pdsm);
return -EINVAL;
}
/* Have enough space to hold returned 'nd_pkg_pdsm' header */
if (nd_cmd->nd_size_out < ND_PDSM_HDR_SIZE) {
dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid payload\n",
pdsm);
return -EINVAL;
}
}
/* Let the command be further processed */
return 0;
}
/*
* 'struct pdsm_cmd_desc'
* Identifies supported PDSMs' expected length of in/out payloads
* and pdsm service function.
*
* size_in : Size of input payload if any in the PDSM request.
* size_out : Size of output payload if any in the PDSM request.
* service : Service function for the PDSM request. Return semantics:
* rc < 0 : Error servicing PDSM and rc indicates the error.
* rc >=0 : Serviced successfully and 'rc' indicate number of
* bytes written to payload.
*/
struct pdsm_cmd_desc {
u32 size_in;
u32 size_out;
int (*service)(struct papr_scm_priv *dimm,
union nd_pdsm_payload *payload);
};
/* Holds all supported PDSMs' command descriptors */
static const struct pdsm_cmd_desc __pdsm_cmd_descriptors[] = {
[PAPR_PDSM_MIN] = {
.size_in = 0,
.size_out = 0,
.service = NULL,
},
/* New PDSM command descriptors to be added below */
/* Empty */
[PAPR_PDSM_MAX] = {
.size_in = 0,
.size_out = 0,
.service = NULL,
},
};
/* Given a valid pdsm cmd return its command descriptor else return NULL */
static inline const struct pdsm_cmd_desc *pdsm_cmd_desc(enum papr_pdsm cmd)
{
if (cmd >= 0 || cmd < ARRAY_SIZE(__pdsm_cmd_descriptors))
return &__pdsm_cmd_descriptors[cmd];
return NULL;
}
/*
* For a given pdsm request call an appropriate service function.
* Returns errors if any while handling the pdsm command package.
*/
static int papr_scm_service_pdsm(struct papr_scm_priv *p,
struct nd_cmd_pkg *pkg)
{
/* Get the PDSM header and PDSM command */
struct nd_pkg_pdsm *pdsm_pkg = (struct nd_pkg_pdsm *)pkg->nd_payload;
enum papr_pdsm pdsm = (enum papr_pdsm)pkg->nd_command;
const struct pdsm_cmd_desc *pdsc;
int rc;
/* Fetch corresponding pdsm descriptor for validation and servicing */
pdsc = pdsm_cmd_desc(pdsm);
/* Validate pdsm descriptor */
/* Ensure that reserved fields are 0 */
if (pdsm_pkg->reserved[0] || pdsm_pkg->reserved[1]) {
dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid reserved field\n",
pdsm);
return -EINVAL;
}
/* If pdsm expects some input, then ensure that the size_in matches */
if (pdsc->size_in &&
pkg->nd_size_in != (pdsc->size_in + ND_PDSM_HDR_SIZE)) {
dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Mismatched size_in=%d\n",
pdsm, pkg->nd_size_in);
return -EINVAL;
}
/* If pdsm wants to return data, then ensure that size_out matches */
if (pdsc->size_out &&
pkg->nd_size_out != (pdsc->size_out + ND_PDSM_HDR_SIZE)) {
dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Mismatched size_out=%d\n",
pdsm, pkg->nd_size_out);
return -EINVAL;
}
/* Service the pdsm */
if (pdsc->service) {
dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Servicing..\n", pdsm);
rc = pdsc->service(p, &pdsm_pkg->payload);
if (rc < 0) {
/* error encountered while servicing pdsm */
pdsm_pkg->cmd_status = rc;
pkg->nd_fw_size = ND_PDSM_HDR_SIZE;
} else {
/* pdsm serviced and 'rc' bytes written to payload */
pdsm_pkg->cmd_status = 0;
pkg->nd_fw_size = ND_PDSM_HDR_SIZE + rc;
}
} else {
dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Unsupported PDSM request\n",
pdsm);
pdsm_pkg->cmd_status = -ENOENT;
pkg->nd_fw_size = ND_PDSM_HDR_SIZE;
}
return pdsm_pkg->cmd_status;
}
static int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, static int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc,
struct nvdimm *nvdimm, unsigned int cmd, void *buf, struct nvdimm *nvdimm, unsigned int cmd, void *buf,
unsigned int buf_len, int *cmd_rc) unsigned int buf_len, int *cmd_rc)
{ {
struct nd_cmd_get_config_size *get_size_hdr; struct nd_cmd_get_config_size *get_size_hdr;
struct nd_cmd_pkg *call_pkg = NULL;
struct papr_scm_priv *p; struct papr_scm_priv *p;
int rc; int rc;
/* Only dimm-specific calls are supported atm */ rc = is_cmd_valid(nvdimm, cmd, buf, buf_len);
if (!nvdimm) if (rc) {
return -EINVAL; pr_debug("Invalid cmd=0x%x. Err=%d\n", cmd, rc);
return rc;
}
/* Use a local variable in case cmd_rc pointer is NULL */ /* Use a local variable in case cmd_rc pointer is NULL */
if (!cmd_rc) if (!cmd_rc)
...@@ -385,6 +565,11 @@ static int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, ...@@ -385,6 +565,11 @@ static int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc,
*cmd_rc = papr_scm_meta_set(p, buf); *cmd_rc = papr_scm_meta_set(p, buf);
break; break;
case ND_CMD_CALL:
call_pkg = (struct nd_cmd_pkg *)buf;
*cmd_rc = papr_scm_service_pdsm(p, call_pkg);
break;
default: default:
dev_dbg(&p->pdev->dev, "Unknown command = %d\n", cmd); dev_dbg(&p->pdev->dev, "Unknown command = %d\n", cmd);
return -EINVAL; return -EINVAL;
......
...@@ -244,6 +244,7 @@ struct nd_cmd_pkg { ...@@ -244,6 +244,7 @@ struct nd_cmd_pkg {
#define NVDIMM_FAMILY_HPE2 2 #define NVDIMM_FAMILY_HPE2 2
#define NVDIMM_FAMILY_MSFT 3 #define NVDIMM_FAMILY_MSFT 3
#define NVDIMM_FAMILY_HYPERV 4 #define NVDIMM_FAMILY_HYPERV 4
#define NVDIMM_FAMILY_PAPR 5
#define ND_IOCTL_CALL _IOWR(ND_IOCTL, ND_CMD_CALL,\ #define ND_IOCTL_CALL _IOWR(ND_IOCTL, ND_CMD_CALL,\
struct nd_cmd_pkg) struct nd_cmd_pkg)
......
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