| Message ID | 20200331143229.306718-4-vaibhav@linux.ibm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | powerpc/papr_scm: Add support for reporting nvdimm health | expand |
Vaibhav Jain <vaibhav@linux.ibm.com> writes: > 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. > Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> > Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> > > --- > 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 <vaibhav at linux.ibm.com> > + * > + * 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 <linux/types.h> > + > +#ifdef __KERNEL__ > +#include <linux/ndctl.h> > +#else > +#include <ndctl.h> > +#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 <asm/plpar_wrappers.h> > #include <asm/papr_scm.h> > +#include <asm/papr_scm_dsm.h> > > #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) > -- > 2.25.1 > _______________________________________________ > Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org > To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
On Tue, Mar 31, 2020 at 7:33 AM Vaibhav Jain <vaibhav@linux.ibm.com> wrote: > > 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. They aren't ACPI Device Specific Methods in the papr_scm case, right? I'd call them what the papr_scm specification calls them and replace "DSM" throughout. > 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(). You don't necessarily need to have command number separation like that. The function number spaces are unique per family. > 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 <vaibhav@linux.ibm.com> > > --- > 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 <vaibhav at linux.ibm.com> > + * > + * 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. These 2 paragraphs of redundant license text can be dropped. The SPDX line is sufficient. > + */ > + > +#ifndef _UAPI_ASM_POWERPC_PAPR_SCM_DSM_H_ > +#define _UAPI_ASM_POWERPC_PAPR_SCM_DSM_H_ > + > +#include <linux/types.h> > + > +#ifdef __KERNEL__ > +#include <linux/ndctl.h> > +#else > +#include <ndctl.h> > +#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 s/envelop/envelope/ There's a difference between commands and functions in libnvdimm. Commands are the top-level ioctl methods where ND_CMD_CALL is the generic payload command and functions are communicated inside of that wrapper. Otherwise if the command does not wrap other commands like ND_CMD_{GET,SET}_CONFIG_DATA then the individual bus providers translate them to the bus-local functionality. For example ND_CMD_{GET,SET}_CONFIG_DATA correspond to either the _LSx ACPI methods, or the Intel DSM label methods. The details of those implementations are hidden from the caller, the caller just sees the kernel's ND_CMD_{GET,SET}_CONFIG_DATA interface. > + * 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 s/envelop/envelope/ > + * 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 s/envelop/envelope/ > + * '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 */ Does this structure pack the same on all compilers? > +}; > + > +/* > + * 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' > + */ With nd_family set to NVDIMM_FAMILY_PAPR_SCM the function number space can overlap the function numbers from other families. > +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 <asm/plpar_wrappers.h> > #include <asm/papr_scm.h> > +#include <asm/papr_scm_dsm.h> > > #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); Please convert all the pr_debug() statements in this file to dev_dbg(). Also you don't need to put the __func__ in the print statement because you can enable that via dynamic_debug_control see the "f" flag in addition to the "p" flag for dynamic debug enabling. > + return -EINVAL; > + } else if (cmd == ND_CMD_CALL) { > + > + /* Verify the envelop package */ s/envelop/envelope/ > + 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) > -- > 2.25.1 >
Dan Williams <dan.j.williams@intel.com> writes: > On Tue, Mar 31, 2020 at 7:33 AM Vaibhav Jain <vaibhav@linux.ibm.com> wrote: >> >> 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. > > They aren't ACPI Device Specific Methods in the papr_scm case, right? > I'd call them what the papr_scm specification calls them and replace > "DSM" throughout. Right, papr_scm doesnt use ACPI. However there is no pre-existing term for these methods as they are defined by us. Hence we reused the "DSM" to indicate meaning similar to what ACPI does. The closest term in papr_scm spec is Hcall thats a system-call to hypervisor to fetch some data. But there is no 1:1 mapping between HCall and these "DSMs". > >> 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(). > > You don't necessarily need to have command number separation like > that. The function number spaces are unique per family. > Right. This is a carry over from previous version of this patchset that tried using ND_CMD_& and PAPR_DSM_* in a single switch-case block. However not needed anymore, hence I will switch to values starting from 0x0 in next iteration. >> 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 <vaibhav@linux.ibm.com> >> >> --- >> 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 <vaibhav at linux.ibm.com> >> + * >> + * 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. > > These 2 paragraphs of redundant license text can be dropped. The SPDX > line is sufficient. Agree, will address this in next iteration. > >> + */ >> + >> +#ifndef _UAPI_ASM_POWERPC_PAPR_SCM_DSM_H_ >> +#define _UAPI_ASM_POWERPC_PAPR_SCM_DSM_H_ >> + >> +#include <linux/types.h> >> + >> +#ifdef __KERNEL__ >> +#include <linux/ndctl.h> >> +#else >> +#include <ndctl.h> >> +#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 > > s/envelop/envelope/ Agree, will fix this and other instances of the same error > > There's a difference between commands and functions in libnvdimm. > Commands are the top-level ioctl methods where ND_CMD_CALL is the > generic payload command and functions are communicated inside of that > wrapper. Otherwise if the command does not wrap other commands like > ND_CMD_{GET,SET}_CONFIG_DATA then the individual bus providers > translate them to the bus-local functionality. For example > ND_CMD_{GET,SET}_CONFIG_DATA correspond to either the _LSx ACPI > methods, or the Intel DSM label methods. The details of those > implementations are hidden from the caller, the caller just sees the > kernel's ND_CMD_{GET,SET}_CONFIG_DATA interface. > >> + * 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 > > s/envelop/envelope/ > >> + * 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 > > s/envelop/envelope/ > >> + * '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 */ > > Does this structure pack the same on all compilers? I tried with both gcc-8.2 and clang-9.0 and pahole reported the same struct layout. > >> +}; >> + >> +/* >> + * 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' >> + */ > > With nd_family set to NVDIMM_FAMILY_PAPR_SCM the function number space > can overlap the function numbers from other families. Agree, will reset DSM_PAPR_SCM_MIN = 0 in next iteration. > >> +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 <asm/plpar_wrappers.h> >> #include <asm/papr_scm.h> >> +#include <asm/papr_scm_dsm.h> >> >> #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); > > Please convert all the pr_debug() statements in this file to > dev_dbg(). Also you don't need to put the __func__ in the print > statement because you can enable that via dynamic_debug_control see > the "f" flag in addition to the "p" flag for dynamic debug enabling. > Fair suggestion. Will update in next iteration. >> + return -EINVAL; >> + } else if (cmd == ND_CMD_CALL) { >> + >> + /* Verify the envelop package */ > > s/envelop/envelope/ > >> + 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) >> -- >> 2.25.1 >>
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 <vaibhav at linux.ibm.com> + * + * 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 <linux/types.h> + +#ifdef __KERNEL__ +#include <linux/ndctl.h> +#else +#include <ndctl.h> +#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 <asm/plpar_wrappers.h> #include <asm/papr_scm.h> +#include <asm/papr_scm_dsm.h> #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)
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 <vaibhav@linux.ibm.com> --- 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