From fc110108b98305efa24bb8c355e90b5cc2a01a5f Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Thu, 18 Apr 2024 10:51:20 +0100 Subject: firmware: arm_scmi: Add support for multiple vendors custom protocols Add a mechanism to be able to tag vendor protocol modules at compile-time with a vendor/sub_vendor string and an implementation version and then to choose to load, at run-time, only those vendor protocol modules matching as close as possible the vendor/subvendor identification advertised by the SCMI platform server. In this way, any in-tree existent vendor protocol module can be build and shipped by default in a single kernel image, even when using the same clashing protocol identification numbers, since the SCMI core will take care at run-time to load only the ones pertinent to the running system. Signed-off-by: Cristian Marussi Link: https://lore.kernel.org/r/20240418095121.3238820-2-cristian.marussi@arm.com Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/driver.c | 169 +++++++++++++++++++++++++++++----- drivers/firmware/arm_scmi/protocols.h | 15 +++ 2 files changed, 162 insertions(+), 22 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 36e3eb50a8d4..36c4ff41dee1 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -33,6 +33,7 @@ #include #include #include +#include #include "common.h" #include "notify.h" @@ -44,8 +45,7 @@ static DEFINE_IDA(scmi_id); -static DEFINE_IDR(scmi_protocols); -static DEFINE_SPINLOCK(protocol_lock); +static DEFINE_XARRAY(scmi_protocols); /* List of all SCMI devices active in system */ static LIST_HEAD(scmi_list); @@ -194,11 +194,94 @@ struct scmi_info { #define bus_nb_to_scmi_info(nb) container_of(nb, struct scmi_info, bus_nb) #define req_nb_to_scmi_info(nb) container_of(nb, struct scmi_info, dev_req_nb) -static const struct scmi_protocol *scmi_protocol_get(int protocol_id) +static unsigned long +scmi_vendor_protocol_signature(unsigned int protocol_id, char *vendor_id, + char *sub_vendor_id, u32 impl_ver) { - const struct scmi_protocol *proto; + char *signature, *p; + unsigned long hash = 0; - proto = idr_find(&scmi_protocols, protocol_id); + /* vendor_id/sub_vendor_id guaranteed <= SCMI_SHORT_NAME_MAX_SIZE */ + signature = kasprintf(GFP_KERNEL, "%02X|%s|%s|0x%08X", protocol_id, + vendor_id ?: "", sub_vendor_id ?: "", impl_ver); + if (!signature) + return 0; + + p = signature; + while (*p) + hash = partial_name_hash(tolower(*p++), hash); + hash = end_name_hash(hash); + + kfree(signature); + + return hash; +} + +static unsigned long +scmi_protocol_key_calculate(int protocol_id, char *vendor_id, + char *sub_vendor_id, u32 impl_ver) +{ + if (protocol_id < SCMI_PROTOCOL_VENDOR_BASE) + return protocol_id; + else + return scmi_vendor_protocol_signature(protocol_id, vendor_id, + sub_vendor_id, impl_ver); +} + +static const struct scmi_protocol * +__scmi_vendor_protocol_lookup(int protocol_id, char *vendor_id, + char *sub_vendor_id, u32 impl_ver) +{ + unsigned long key; + struct scmi_protocol *proto = NULL; + + key = scmi_protocol_key_calculate(protocol_id, vendor_id, + sub_vendor_id, impl_ver); + if (key) + proto = xa_load(&scmi_protocols, key); + + return proto; +} + +static const struct scmi_protocol * +scmi_vendor_protocol_lookup(int protocol_id, char *vendor_id, + char *sub_vendor_id, u32 impl_ver) +{ + const struct scmi_protocol *proto = NULL; + + /* Searching for closest match ...*/ + proto = __scmi_vendor_protocol_lookup(protocol_id, vendor_id, + sub_vendor_id, impl_ver); + if (proto) + return proto; + + /* Any match just on vendor/sub_vendor ? */ + if (impl_ver) { + proto = __scmi_vendor_protocol_lookup(protocol_id, vendor_id, + sub_vendor_id, 0); + if (proto) + return proto; + } + + /* Any match just on the vendor ? */ + if (sub_vendor_id) + proto = __scmi_vendor_protocol_lookup(protocol_id, vendor_id, + NULL, 0); + return proto; +} + +static const struct scmi_protocol * +scmi_protocol_get(int protocol_id, struct scmi_revision_info *version) +{ + const struct scmi_protocol *proto = NULL; + + if (protocol_id < SCMI_PROTOCOL_VENDOR_BASE) + proto = xa_load(&scmi_protocols, protocol_id); + else + proto = scmi_vendor_protocol_lookup(protocol_id, + version->vendor_id, + version->sub_vendor_id, + version->impl_ver); if (!proto || !try_module_get(proto->owner)) { pr_warn("SCMI Protocol 0x%x not found!\n", protocol_id); return NULL; @@ -206,21 +289,46 @@ static const struct scmi_protocol *scmi_protocol_get(int protocol_id) pr_debug("Found SCMI Protocol 0x%x\n", protocol_id); + if (protocol_id >= SCMI_PROTOCOL_VENDOR_BASE) + pr_info("Loaded SCMI Vendor Protocol 0x%x - %s %s %X\n", + protocol_id, proto->vendor_id ?: "", + proto->sub_vendor_id ?: "", proto->impl_ver); + return proto; } -static void scmi_protocol_put(int protocol_id) +static void scmi_protocol_put(const struct scmi_protocol *proto) { - const struct scmi_protocol *proto; - - proto = idr_find(&scmi_protocols, protocol_id); if (proto) module_put(proto->owner); } +static int scmi_vendor_protocol_check(const struct scmi_protocol *proto) +{ + if (!proto->vendor_id) { + pr_err("missing vendor_id for protocol 0x%x\n", proto->id); + return -EINVAL; + } + + if (strlen(proto->vendor_id) >= SCMI_SHORT_NAME_MAX_SIZE) { + pr_err("malformed vendor_id for protocol 0x%x\n", proto->id); + return -EINVAL; + } + + if (proto->sub_vendor_id && + strlen(proto->sub_vendor_id) >= SCMI_SHORT_NAME_MAX_SIZE) { + pr_err("malformed sub_vendor_id for protocol 0x%x\n", + proto->id); + return -EINVAL; + } + + return 0; +} + int scmi_protocol_register(const struct scmi_protocol *proto) { int ret; + unsigned long key; if (!proto) { pr_err("invalid protocol\n"); @@ -232,12 +340,23 @@ int scmi_protocol_register(const struct scmi_protocol *proto) return -EINVAL; } - spin_lock(&protocol_lock); - ret = idr_alloc(&scmi_protocols, (void *)proto, - proto->id, proto->id + 1, GFP_ATOMIC); - spin_unlock(&protocol_lock); - if (ret != proto->id) { - pr_err("unable to allocate SCMI idr slot for 0x%x - err %d\n", + if (proto->id >= SCMI_PROTOCOL_VENDOR_BASE && + scmi_vendor_protocol_check(proto)) + return -EINVAL; + + /* + * Calculate a protocol key to register this protocol with the core; + * key value 0 is considered invalid. + */ + key = scmi_protocol_key_calculate(proto->id, proto->vendor_id, + proto->sub_vendor_id, + proto->impl_ver); + if (!key) + return -EINVAL; + + ret = xa_insert(&scmi_protocols, key, (void *)proto, GFP_KERNEL); + if (ret) { + pr_err("unable to allocate SCMI protocol slot for 0x%x - err %d\n", proto->id, ret); return ret; } @@ -250,9 +369,15 @@ EXPORT_SYMBOL_GPL(scmi_protocol_register); void scmi_protocol_unregister(const struct scmi_protocol *proto) { - spin_lock(&protocol_lock); - idr_remove(&scmi_protocols, proto->id); - spin_unlock(&protocol_lock); + unsigned long key; + + key = scmi_protocol_key_calculate(proto->id, proto->vendor_id, + proto->sub_vendor_id, + proto->impl_ver); + if (!key) + return; + + xa_erase(&scmi_protocols, key); pr_debug("Unregistered SCMI Protocol 0x%x\n", proto->id); } @@ -1940,7 +2065,7 @@ scmi_alloc_init_protocol_instance(struct scmi_info *info, /* Protocol specific devres group */ gid = devres_open_group(handle->dev, NULL, GFP_KERNEL); if (!gid) { - scmi_protocol_put(proto->id); + scmi_protocol_put(proto); goto out; } @@ -2004,7 +2129,7 @@ scmi_alloc_init_protocol_instance(struct scmi_info *info, clean: /* Take care to put the protocol module's owner before releasing all */ - scmi_protocol_put(proto->id); + scmi_protocol_put(proto); devres_release_group(handle->dev, gid); out: return ERR_PTR(ret); @@ -2038,7 +2163,7 @@ scmi_get_protocol_instance(const struct scmi_handle *handle, u8 protocol_id) const struct scmi_protocol *proto; /* Fails if protocol not registered on bus */ - proto = scmi_protocol_get(protocol_id); + proto = scmi_protocol_get(protocol_id, &info->version); if (proto) pi = scmi_alloc_init_protocol_instance(info, proto); else @@ -2093,7 +2218,7 @@ void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id) idr_remove(&info->protocols, protocol_id); - scmi_protocol_put(protocol_id); + scmi_protocol_put(pi->proto); devres_release_group(handle->dev, gid); dev_dbg(handle->dev, "De-Initialized protocol: 0x%X\n", diff --git a/drivers/firmware/arm_scmi/protocols.h b/drivers/firmware/arm_scmi/protocols.h index 317d3fb32676..e17dbcfbf299 100644 --- a/drivers/firmware/arm_scmi/protocols.h +++ b/drivers/firmware/arm_scmi/protocols.h @@ -29,6 +29,8 @@ #define PROTOCOL_REV_MAJOR(x) ((u16)(FIELD_GET(PROTOCOL_REV_MAJOR_MASK, (x)))) #define PROTOCOL_REV_MINOR(x) ((u16)(FIELD_GET(PROTOCOL_REV_MINOR_MASK, (x)))) +#define SCMI_PROTOCOL_VENDOR_BASE 0x80 + enum scmi_common_cmd { PROTOCOL_VERSION = 0x0, PROTOCOL_ATTRIBUTES = 0x1, @@ -323,6 +325,16 @@ typedef int (*scmi_prot_init_ph_fn_t)(const struct scmi_protocol_handle *); * protocol by the agent. Each protocol implementation * in the agent is supposed to downgrade to match the * protocol version supported by the platform. + * @vendor_id: A firmware vendor string for vendor protocols matching. + * Ignored when @id identifies a standard protocol, cannot be NULL + * otherwise. + * @sub_vendor_id: A firmware sub_vendor string for vendor protocols matching. + * Ignored if NULL or when @id identifies a standard protocol. + * @impl_ver: A firmware implementation version for vendor protocols matching. + * Ignored if zero or if @id identifies a standard protocol. + * + * Note that vendor protocols matching at load time is performed by attempting + * the closest match first against the tuple (vendor, sub_vendor, impl_ver) */ struct scmi_protocol { const u8 id; @@ -332,6 +344,9 @@ struct scmi_protocol { const void *ops; const struct scmi_protocol_events *events; unsigned int supported_version; + char *vendor_id; + char *sub_vendor_id; + u32 impl_ver; }; #define DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(name, proto) \ -- cgit v1.2.3