diff options
Diffstat (limited to 'drivers/firmware/arm_scmi')
| -rw-r--r-- | drivers/firmware/arm_scmi/Kconfig | 41 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/common.h | 26 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/driver.c | 207 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/mailbox.c | 3 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/optee.c | 567 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/smc.c | 98 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/virtio.c | 22 |
8 files changed, 885 insertions, 80 deletions
diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/Kconfig index 3d7081e84853..d429326433d1 100644 --- a/drivers/firmware/arm_scmi/Kconfig +++ b/drivers/firmware/arm_scmi/Kconfig @@ -54,6 +54,18 @@ config ARM_SCMI_TRANSPORT_MAILBOX If you want the ARM SCMI PROTOCOL stack to include support for a transport based on mailboxes, answer Y. +config ARM_SCMI_TRANSPORT_OPTEE + bool "SCMI transport based on OP-TEE service" + depends on OPTEE=y || OPTEE=ARM_SCMI_PROTOCOL + select ARM_SCMI_HAVE_TRANSPORT + select ARM_SCMI_HAVE_SHMEM + default y + help + This enables the OP-TEE service based transport for SCMI. + + If you want the ARM SCMI PROTOCOL stack to include support for a + transport based on OP-TEE SCMI service, answer Y. + config ARM_SCMI_TRANSPORT_SMC bool "SCMI transport based on SMC" depends on HAVE_ARM_SMCCC_DISCOVERY @@ -66,6 +78,20 @@ config ARM_SCMI_TRANSPORT_SMC If you want the ARM SCMI PROTOCOL stack to include support for a transport based on SMC, answer Y. +config ARM_SCMI_TRANSPORT_SMC_ATOMIC_ENABLE + bool "Enable atomic mode support for SCMI SMC transport" + depends on ARM_SCMI_TRANSPORT_SMC + help + Enable support of atomic operation for SCMI SMC based transport. + + If you want the SCMI SMC based transport to operate in atomic + mode, avoiding any kind of sleeping behaviour for selected + transactions on the TX path, answer Y. + Enabling atomic mode operations allows any SCMI driver using this + transport to optionally ask for atomic SCMI transactions and operate + in atomic context too, at the price of using a number of busy-waiting + primitives all over instead. If unsure say N. + config ARM_SCMI_TRANSPORT_VIRTIO bool "SCMI transport based on VirtIO" depends on VIRTIO=y || VIRTIO=ARM_SCMI_PROTOCOL @@ -77,6 +103,21 @@ config ARM_SCMI_TRANSPORT_VIRTIO If you want the ARM SCMI PROTOCOL stack to include support for a transport based on VirtIO, answer Y. +config ARM_SCMI_TRANSPORT_VIRTIO_VERSION1_COMPLIANCE + bool "SCMI VirtIO transport Version 1 compliance" + depends on ARM_SCMI_TRANSPORT_VIRTIO + default y + help + This enforces strict compliance with VirtIO Version 1 specification. + + If you want the ARM SCMI VirtIO transport layer to refuse to work + with Legacy VirtIO backends and instead support only VirtIO Version 1 + devices (or above), answer Y. + + If you want instead to support also old Legacy VirtIO backends (like + the ones implemented by kvmtool) and let the core Kernel VirtIO layer + take care of the needed conversions, say N. + endif #ARM_SCMI_PROTOCOL config ARM_SCMI_POWER_DOMAIN diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile index 1dcf123d64ab..ef66ec8ca917 100644 --- a/drivers/firmware/arm_scmi/Makefile +++ b/drivers/firmware/arm_scmi/Makefile @@ -6,6 +6,7 @@ scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_MAILBOX) += mailbox.o scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_SMC) += smc.o scmi-transport-$(CONFIG_ARM_SCMI_HAVE_MSG) += msg.o scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_VIRTIO) += virtio.o +scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_OPTEE) += optee.o scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o system.o voltage.o scmi-module-objs := $(scmi-bus-y) $(scmi-driver-y) $(scmi-protocols-y) \ $(scmi-transport-y) diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h index dea1bfbe1052..4fda84bfab42 100644 --- a/drivers/firmware/arm_scmi/common.h +++ b/drivers/firmware/arm_scmi/common.h @@ -339,11 +339,16 @@ void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id); * @dev: Reference to device in the SCMI hierarchy corresponding to this * channel * @handle: Pointer to SCMI entity handle + * @no_completion_irq: Flag to indicate that this channel has no completion + * interrupt mechanism for synchronous commands. + * This can be dynamically set by transports at run-time + * inside their provided .chan_setup(). * @transport_info: Transport layer related information */ struct scmi_chan_info { struct device *dev; struct scmi_handle *handle; + bool no_completion_irq; void *transport_info; }; @@ -373,7 +378,8 @@ struct scmi_transport_ops { unsigned int (*get_max_msg)(struct scmi_chan_info *base_cinfo); int (*send_message)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer); - void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret); + void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret, + struct scmi_xfer *xfer); void (*fetch_response)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer); void (*fetch_notification)(struct scmi_chan_info *cinfo, @@ -402,6 +408,18 @@ struct scmi_device *scmi_child_dev_find(struct device *parent, * be pending simultaneously in the system. May be overridden by the * get_max_msg op. * @max_msg_size: Maximum size of data per message that can be handled. + * @force_polling: Flag to force this whole transport to use SCMI core polling + * mechanism instead of completion interrupts even if available. + * @sync_cmds_completed_on_ret: Flag to indicate that the transport assures + * synchronous-command messages are atomically + * completed on .send_message: no need to poll + * actively waiting for a response. + * Used by core internally only when polling is + * selected as a waiting for reply method: i.e. + * if a completion irq was found use that anyway. + * @atomic_enabled: Flag to indicate that this transport, which is assured not + * to sleep anywhere on the TX path, can be used in atomic mode + * when requested. */ struct scmi_desc { int (*transport_init)(void); @@ -410,6 +428,9 @@ struct scmi_desc { int max_rx_timeout_ms; int max_msg; int max_msg_size; + const bool force_polling; + const bool sync_cmds_completed_on_ret; + const bool atomic_enabled; }; #ifdef CONFIG_ARM_SCMI_TRANSPORT_MAILBOX @@ -421,6 +442,9 @@ extern const struct scmi_desc scmi_smc_desc; #ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO extern const struct scmi_desc scmi_virtio_desc; #endif +#ifdef CONFIG_ARM_SCMI_TRANSPORT_OPTEE +extern const struct scmi_desc scmi_optee_desc; +#endif void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv); void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id); diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index b406b3f78f46..c2e7897ff56e 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -609,6 +609,25 @@ static inline void scmi_clear_channel(struct scmi_info *info, info->desc->ops->clear_channel(cinfo); } +static inline bool is_polling_required(struct scmi_chan_info *cinfo, + struct scmi_info *info) +{ + return cinfo->no_completion_irq || info->desc->force_polling; +} + +static inline bool is_transport_polling_capable(struct scmi_info *info) +{ + return info->desc->ops->poll_done || + info->desc->sync_cmds_completed_on_ret; +} + +static inline bool is_polling_enabled(struct scmi_chan_info *cinfo, + struct scmi_info *info) +{ + return is_polling_required(cinfo, info) && + is_transport_polling_capable(info); +} + static void scmi_handle_notification(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv) { @@ -724,8 +743,6 @@ static void xfer_put(const struct scmi_protocol_handle *ph, __scmi_xfer_put(&info->tx_minfo, xfer); } -#define SCMI_MAX_POLL_TO_NS (100 * NSEC_PER_USEC) - static bool scmi_xfer_done_no_timeout(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer, ktime_t stop) { @@ -741,6 +758,79 @@ static bool scmi_xfer_done_no_timeout(struct scmi_chan_info *cinfo, } /** + * scmi_wait_for_message_response - An helper to group all the possible ways of + * waiting for a synchronous message response. + * + * @cinfo: SCMI channel info + * @xfer: Reference to the transfer being waited for. + * + * Chooses waiting strategy (sleep-waiting vs busy-waiting) depending on + * configuration flags like xfer->hdr.poll_completion. + * + * Return: 0 on Success, error otherwise. + */ +static int scmi_wait_for_message_response(struct scmi_chan_info *cinfo, + struct scmi_xfer *xfer) +{ + struct scmi_info *info = handle_to_scmi_info(cinfo->handle); + struct device *dev = info->dev; + int ret = 0, timeout_ms = info->desc->max_rx_timeout_ms; + + trace_scmi_xfer_response_wait(xfer->transfer_id, xfer->hdr.id, + xfer->hdr.protocol_id, xfer->hdr.seq, + timeout_ms, + xfer->hdr.poll_completion); + + if (xfer->hdr.poll_completion) { + /* + * Real polling is needed only if transport has NOT declared + * itself to support synchronous commands replies. + */ + if (!info->desc->sync_cmds_completed_on_ret) { + /* + * Poll on xfer using transport provided .poll_done(); + * assumes no completion interrupt was available. + */ + ktime_t stop = ktime_add_ms(ktime_get(), timeout_ms); + + spin_until_cond(scmi_xfer_done_no_timeout(cinfo, + xfer, stop)); + if (ktime_after(ktime_get(), stop)) { + dev_err(dev, + "timed out in resp(caller: %pS) - polling\n", + (void *)_RET_IP_); + ret = -ETIMEDOUT; + } + } + + if (!ret) { + unsigned long flags; + + /* + * Do not fetch_response if an out-of-order delayed + * response is being processed. + */ + spin_lock_irqsave(&xfer->lock, flags); + if (xfer->state == SCMI_XFER_SENT_OK) { + info->desc->ops->fetch_response(cinfo, xfer); + xfer->state = SCMI_XFER_RESP_OK; + } + spin_unlock_irqrestore(&xfer->lock, flags); + } + } else { + /* And we wait for the response. */ + if (!wait_for_completion_timeout(&xfer->done, + msecs_to_jiffies(timeout_ms))) { + dev_err(dev, "timed out in resp(caller: %pS)\n", + (void *)_RET_IP_); + ret = -ETIMEDOUT; + } + } + + return ret; +} + +/** * do_xfer() - Do one transfer * * @ph: Pointer to SCMI protocol handle @@ -754,18 +844,26 @@ static int do_xfer(const struct scmi_protocol_handle *ph, struct scmi_xfer *xfer) { int ret; - int timeout; const struct scmi_protocol_instance *pi = ph_to_pi(ph); struct scmi_info *info = handle_to_scmi_info(pi->handle); struct device *dev = info->dev; struct scmi_chan_info *cinfo; - if (xfer->hdr.poll_completion && !info->desc->ops->poll_done) { + /* Check for polling request on custom command xfers at first */ + if (xfer->hdr.poll_completion && !is_transport_polling_capable(info)) { dev_warn_once(dev, "Polling mode is not supported by transport.\n"); return -EINVAL; } + cinfo = idr_find(&info->tx_idr, pi->proto->id); + if (unlikely(!cinfo)) + return -EINVAL; + + /* True ONLY if also supported by transport. */ + if (is_polling_enabled(cinfo, info)) + xfer->hdr.poll_completion = true; + /* * Initialise protocol id now from protocol handle to avoid it being * overridden by mistake (or malice) by the protocol code mangling with @@ -774,10 +872,6 @@ static int do_xfer(const struct scmi_protocol_handle *ph, xfer->hdr.protocol_id = pi->proto->id; reinit_completion(&xfer->done); - cinfo = idr_find(&info->tx_idr, xfer->hdr.protocol_id); - if (unlikely(!cinfo)) - return -EINVAL; - trace_scmi_xfer_begin(xfer->transfer_id, xfer->hdr.id, xfer->hdr.protocol_id, xfer->hdr.seq, xfer->hdr.poll_completion); @@ -798,41 +892,12 @@ static int do_xfer(const struct scmi_protocol_handle *ph, return ret; } - if (xfer->hdr.poll_completion) { - ktime_t stop = ktime_add_ns(ktime_get(), SCMI_MAX_POLL_TO_NS); - - spin_until_cond(scmi_xfer_done_no_timeout(cinfo, xfer, stop)); - if (ktime_before(ktime_get(), stop)) { - unsigned long flags; - - /* - * Do not fetch_response if an out-of-order delayed - * response is being processed. - */ - spin_lock_irqsave(&xfer->lock, flags); - if (xfer->state == SCMI_XFER_SENT_OK) { - info->desc->ops->fetch_response(cinfo, xfer); - xfer->state = SCMI_XFER_RESP_OK; - } - spin_unlock_irqrestore(&xfer->lock, flags); - } else { - ret = -ETIMEDOUT; - } - } else { - /* And we wait for the response. */ - timeout = msecs_to_jiffies(info->desc->max_rx_timeout_ms); - if (!wait_for_completion_timeout(&xfer->done, timeout)) { - dev_err(dev, "timed out in resp(caller: %pS)\n", - (void *)_RET_IP_); - ret = -ETIMEDOUT; - } - } - + ret = scmi_wait_for_message_response(cinfo, xfer); if (!ret && xfer->hdr.status) ret = scmi_to_linux_errno(xfer->hdr.status); if (info->desc->ops->mark_txdone) - info->desc->ops->mark_txdone(cinfo, ret); + info->desc->ops->mark_txdone(cinfo, ret, xfer); trace_scmi_xfer_end(xfer->transfer_id, xfer->hdr.id, xfer->hdr.protocol_id, xfer->hdr.seq, ret); @@ -858,6 +923,20 @@ static void reset_rx_to_maxsz(const struct scmi_protocol_handle *ph, * @ph: Pointer to SCMI protocol handle * @xfer: Transfer to initiate and wait for response * + * Using asynchronous commands in atomic/polling mode should be avoided since + * it could cause long busy-waiting here, so ignore polling for the delayed + * response and WARN if it was requested for this command transaction since + * upper layers should refrain from issuing such kind of requests. + * + * The only other option would have been to refrain from using any asynchronous + * command even if made available, when an atomic transport is detected, and + * instead forcibly use the synchronous version (thing that can be easily + * attained at the protocol layer), but this would also have led to longer + * stalls of the channel for synchronous commands and possibly timeouts. + * (in other words there is usually a good reason if a platform provides an + * asynchronous version of a command and we should prefer to use it...just not + * when using atomic/polling mode) + * * Return: -ETIMEDOUT in case of no delayed response, if transmit error, * return corresponding error, else if all goes well, return 0. */ @@ -869,12 +948,24 @@ static int do_xfer_with_response(const struct scmi_protocol_handle *ph, xfer->async_done = &async_response; + /* + * Delayed responses should not be polled, so an async command should + * not have been used when requiring an atomic/poll context; WARN and + * perform instead a sleeping wait. + * (Note Async + IgnoreDelayedResponses are sent via do_xfer) + */ + WARN_ON_ONCE(xfer->hdr.poll_completion); + ret = do_xfer(ph, xfer); if (!ret) { - if (!wait_for_completion_timeout(xfer->async_done, timeout)) + if (!wait_for_completion_timeout(xfer->async_done, timeout)) { + dev_err(ph->dev, + "timed out in delayed resp(caller: %pS)\n", + (void *)_RET_IP_); ret = -ETIMEDOUT; - else if (xfer->hdr.status) + } else if (xfer->hdr.status) { ret = scmi_to_linux_errno(xfer->hdr.status); + } } xfer->async_done = NULL; @@ -1308,6 +1399,22 @@ static void scmi_devm_protocol_put(struct scmi_device *sdev, u8 protocol_id) WARN_ON(ret); } +/** + * scmi_is_transport_atomic - Method to check if underlying transport for an + * SCMI instance is configured as atomic. + * + * @handle: A reference to the SCMI platform instance. + * + * Return: True if transport is configured as atomic + */ +static bool scmi_is_transport_atomic(const struct scmi_handle *handle) +{ + struct scmi_info *info = handle_to_scmi_info(handle); + + return info->desc->atomic_enabled && + is_transport_polling_capable(info); +} + static inline struct scmi_handle *scmi_handle_get_from_info_unlocked(struct scmi_info *info) { @@ -1499,6 +1606,16 @@ static int scmi_chan_setup(struct scmi_info *info, struct device *dev, if (ret) return ret; + if (tx && is_polling_required(cinfo, info)) { + if (is_transport_polling_capable(info)) + dev_info(dev, + "Enabled polling mode TX channel - prot_id:%d\n", + prot_id); + else + dev_warn(dev, + "Polling mode NOT supported by transport.\n"); + } + idr_alloc: ret = idr_alloc(idr, cinfo, prot_id, prot_id + 1, GFP_KERNEL); if (ret != prot_id) { @@ -1835,6 +1952,7 @@ static int scmi_probe(struct platform_device *pdev) handle->version = &info->version; handle->devm_protocol_get = scmi_devm_protocol_get; handle->devm_protocol_put = scmi_devm_protocol_put; + handle->is_transport_atomic = scmi_is_transport_atomic; if (desc->ops->link_supplier) { ret = desc->ops->link_supplier(dev); @@ -1853,6 +1971,10 @@ static int scmi_probe(struct platform_device *pdev) if (scmi_notification_init(handle)) dev_err(dev, "SCMI Notifications NOT available.\n"); + if (info->desc->atomic_enabled && !is_transport_polling_capable(info)) + dev_err(dev, + "Transport is not polling capable. Atomic mode not supported.\n"); + /* * Trigger SCMI Base protocol initialization. * It's mandatory and won't be ever released/deinit until the @@ -1994,6 +2116,9 @@ static const struct of_device_id scmi_of_match[] = { #ifdef CONFIG_ARM_SCMI_TRANSPORT_MAILBOX { .compatible = "arm,scmi", .data = &scmi_mailbox_desc }, #endif +#ifdef CONFIG_ARM_SCMI_TRANSPORT_OPTEE + { .compatible = "linaro,scmi-optee", .data = &scmi_optee_desc }, +#endif #ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC { .compatible = "arm,scmi-smc", .data = &scmi_smc_desc}, #endif diff --git a/drivers/firmware/arm_scmi/mailbox.c b/drivers/firmware/arm_scmi/mailbox.c index e09eb12bf421..08ff4d110beb 100644 --- a/drivers/firmware/arm_scmi/mailbox.c +++ b/drivers/firmware/arm_scmi/mailbox.c @@ -140,7 +140,8 @@ static int mailbox_send_message(struct scmi_chan_info *cinfo, return ret; } -static void mailbox_mark_txdone(struct scmi_chan_info *cinfo, int ret) +static void mailbox_mark_txdone(struct scmi_chan_info *cinfo, int ret, + struct scmi_xfer *__unused) { struct scmi_mailbox *smbox = cinfo->transport_info; diff --git a/drivers/firmware/arm_scmi/optee.c b/drivers/firmware/arm_scmi/optee.c new file mode 100644 index 000000000000..734f1eeee161 --- /dev/null +++ b/drivers/firmware/arm_scmi/optee.c @@ -0,0 +1,567 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019-2021 Linaro Ltd. + */ + +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/tee_drv.h> +#include <linux/uuid.h> +#include <uapi/linux/tee.h> + +#include "common.h" + +#define SCMI_OPTEE_MAX_MSG_SIZE 128 + +enum scmi_optee_pta_cmd { + /* + * PTA_SCMI_CMD_CAPABILITIES - Get channel capabilities + * + * [out] value[0].a: Capability bit mask (enum pta_scmi_caps) + * [out] value[0].b: Extended capabilities or 0 + */ + PTA_SCMI_CMD_CAPABILITIES = 0, + + /* + * PTA_SCMI_CMD_PROCESS_SMT_CHANNEL - Process SCMI message in SMT buffer + * + * [in] value[0].a: Channel handle + * + * Shared memory used for SCMI message/response exhange is expected + * already identified and bound to channel handle in both SCMI agent + * and SCMI server (OP-TEE) parts. + * The memory uses SMT header to carry SCMI meta-data (protocol ID and + * protocol message ID). + */ + PTA_SCMI_CMD_PROCESS_SMT_CHANNEL = 1, + + /* + * PTA_SCMI_CMD_PROCESS_SMT_CHANNEL_MESSAGE - Process SMT/SCMI message + * + * [in] value[0].a: Channel handle + * [in/out] memref[1]: Message/response buffer (SMT and SCMI payload) + * + * Shared memory used for SCMI message/response is a SMT buffer + * referenced by param[1]. It shall be 128 bytes large to fit response + * payload whatever message playload size. + * The memory uses SMT header to carry SCMI meta-data (protocol ID and + * protocol message ID). + */ + PTA_SCMI_CMD_PROCESS_SMT_CHANNEL_MESSAGE = 2, + + /* + * PTA_SCMI_CMD_GET_CHANNEL - Get channel handle + * + * SCMI shm information are 0 if agent expects to use OP-TEE regular SHM + * + * [in] value[0].a: Channel identifier + * [out] value[0].a: Returned channel handle + * [in] value[0].b: Requested capabilities mask (enum pta_scmi_caps) + */ + PTA_SCMI_CMD_GET_CHANNEL = 3, +}; + +/* + * OP-TEE SCMI service capabilities bit flags (32bit) + * + * PTA_SCMI_CAPS_SMT_HEADER + * When set, OP-TEE supports command using SMT header protocol (SCMI shmem) in + * shared memory buffers to carry SCMI protocol synchronisation information. + */ +#define PTA_SCMI_CAPS_NONE 0 +#define PTA_SCMI_CAPS_SMT_HEADER BIT(0) + +/** + * struct scmi_optee_channel - Description of an OP-TEE SCMI channel + * + * @channel_id: OP-TEE channel ID used for this transport + * @tee_session: TEE session identifier + * @caps: OP-TEE SCMI channel capabilities + * @mu: Mutex protection on channel access + * @cinfo: SCMI channel information + * @shmem: Virtual base address of the shared memory + * @tee_shm: Reference to TEE shared memory or NULL if using static shmem + * @link: Reference in agent's channel list + */ +struct scmi_optee_channel { + u32 channel_id; + u32 tee_session; + u32 caps; + struct mutex mu; + struct scmi_chan_info *cinfo; + struct scmi_shared_mem __iomem *shmem; + struct tee_shm *tee_shm; + struct list_head link; +}; + +/** + * struct scmi_optee_agent - OP-TEE transport private data + * + * @dev: Device used for communication with TEE + * @tee_ctx: TEE context used for communication + * @caps: Supported channel capabilities + * @mu: Mutex for protection of @channel_list + * @channel_list: List of all created channels for the agent + */ +struct scmi_optee_agent { + struct device *dev; + struct tee_context *tee_ctx; + u32 caps; + struct mutex mu; + struct list_head channel_list; +}; + +/* There can be only 1 SCMI service in OP-TEE we connect to */ +static struct scmi_optee_agent *scmi_optee_private; + +/* Forward reference to scmi_optee transport initialization */ +static int scmi_optee_init(void); + +/* Open a session toward SCMI OP-TEE service with REE_KERNEL identity */ +static int open_session(struct scmi_optee_agent *agent, u32 *tee_session) +{ + struct device *dev = agent->dev; + struct tee_client_device *scmi_pta = to_tee_client_device(dev); + struct tee_ioctl_open_session_arg arg = { }; + int ret; + + memcpy(arg.uuid, scmi_pta->id.uuid.b, TEE_IOCTL_UUID_LEN); + arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL; + + ret = tee_client_open_session(agent->tee_ctx, &arg, NULL); + if (ret < 0 || arg.ret) { + dev_err(dev, "Can't open tee session: %d / %#x\n", ret, arg.ret); + return -EOPNOTSUPP; + } + + *tee_session = arg.session; + + return 0; +} + +static void close_session(struct scmi_optee_agent *agent, u32 tee_session) +{ + tee_client_close_session(agent->tee_ctx, tee_session); +} + +static int get_capabilities(struct scmi_optee_agent *agent) +{ + struct tee_ioctl_invoke_arg arg = { }; + struct tee_param param[1] = { }; + u32 caps; + u32 tee_session; + int ret; + + ret = open_session(agent, &tee_session); + if (ret) + return ret; + + arg.func = PTA_SCMI_CMD_CAPABILITIES; + arg.session = tee_session; + arg.num_params = 1; + + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT; + + ret = tee_client_invoke_func(agent->tee_ctx, &arg, param); + + close_session(agent, tee_session); + + if (ret < 0 || arg.ret) { + dev_err(agent->dev, "Can't get capabilities: %d / %#x\n", ret, arg.ret); + return -EOPNOTSUPP; + } + + caps = param[0].u.value.a; + + if (!(caps & PTA_SCMI_CAPS_SMT_HEADER)) { + dev_err(agent->dev, "OP-TEE SCMI PTA doesn't support SMT\n"); + return -EOPNOTSUPP; + } + + agent->caps = caps; + + return 0; +} + +static int get_channel(struct scmi_optee_channel *channel) +{ + struct device *dev = scmi_optee_private->dev; + struct tee_ioctl_invoke_arg arg = { }; + struct tee_param param[1] = { }; + unsigned int caps = PTA_SCMI_CAPS_SMT_HEADER; + int ret; + + arg.func = PTA_SCMI_CMD_GET_CHANNEL; + arg.session = channel->tee_session; + arg.num_params = 1; + + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT; + param[0].u.value.a = channel->channel_id; + param[0].u.value.b = caps; + + ret = tee_client_invoke_func(scmi_optee_private->tee_ctx, &arg, param); + + if (ret || arg.ret) { + dev_err(dev, "Can't get channel with caps %#x: %d / %#x\n", caps, ret, arg.ret); + return -EOPNOTSUPP; + } + + /* From now on use channel identifer provided by OP-TEE SCMI service */ + channel->channel_id = param[0].u.value.a; + channel->caps = caps; + + return 0; +} + +static int invoke_process_smt_channel(struct scmi_optee_channel *channel) +{ + struct tee_ioctl_invoke_arg arg = { }; + struct tee_param param[2] = { }; + int ret; + + arg.session = channel->tee_session; + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT; + param[0].u.value.a = channel->channel_id; + + if (channel->tee_shm) { + param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT; + param[1].u.memref.shm = channel->tee_shm; + param[1].u.memref.size = SCMI_OPTEE_MAX_MSG_SIZE; + arg.num_params = 2; + arg.func = PTA_SCMI_CMD_PROCESS_SMT_CHANNEL_MESSAGE; + } else { + arg.num_params = 1; + arg.func = PTA_SCMI_CMD_PROCESS_SMT_CHANNEL; + } + + ret = tee_client_invoke_func(scmi_optee_private->tee_ctx, &arg, param); + if (ret < 0 || arg.ret) { + dev_err(scmi_optee_private->dev, "Can't invoke channel %u: %d / %#x\n", + channel->channel_id, ret, arg.ret); + return -EIO; + } + + return 0; +} + +static int scmi_optee_link_supplier(struct device *dev) +{ + if (!scmi_optee_private) { + if (scmi_optee_init()) + dev_dbg(dev, "Optee bus not yet ready\n"); + + /* Wait for optee bus */ + return -EPROBE_DEFER; + } + + if (!device_link_add(dev, scmi_optee_private->dev, DL_FLAG_AUTOREMOVE_CONSUMER)) { + dev_err(dev, "Adding link to supplier optee device failed\n"); + return -ECANCELED; + } + + return 0; +} + +static bool scmi_optee_chan_available(struct device *dev, int idx) +{ + u32 channel_id; + + return !of_property_read_u32_index(dev->of_node, "linaro,optee-channel-id", + idx, &channel_id); +} + +static void scmi_optee_clear_channel(struct scmi_chan_info *cinfo) +{ + struct scmi_optee_channel *channel = cinfo->transport_info; + + shmem_clear_channel(channel->shmem); +} + +static int setup_static_shmem(struct device *dev, struct scmi_chan_info *cinfo, + struct scmi_optee_channel *channel) +{ + struct device_node *np; + resource_size_t size; + struct resource res; + int ret; + + np = of_parse_phandle(cinfo->dev->of_node, "shmem", 0); + if (!of_device_is_compatible(np, "arm,scmi-shmem")) { + ret = -ENXIO; + goto out; + } + + ret = of_address_to_resource(np, 0, &res); + if (ret) { + dev_err(dev, "Failed to get SCMI Tx shared memory\n"); + goto out; + } + + size = resource_size(&res); + + channel->shmem = devm_ioremap(dev, res.start, size); + if (!channel->shmem) { + dev_err(dev, "Failed to ioremap SCMI Tx shared memory\n"); + ret = -EADDRNOTAVAIL; + goto out; + } + + ret = 0; + +out: + of_node_put(np); + + return ret; +} + +static int setup_shmem(struct device *dev, struct scmi_chan_info *cinfo, + struct scmi_optee_channel *channel) +{ + if (of_find_property(cinfo->dev->of_node, "shmem", NULL)) + return setup_static_shmem(dev, cinfo, channel); + else + return -ENOMEM; +} + +static int scmi_optee_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, bool tx) +{ + struct scmi_optee_channel *channel; + uint32_t channel_id; + int ret; + + if (!tx) + return -ENODEV; + + channel = devm_kzalloc(dev, sizeof(*channel), GFP_KERNEL); + if (!channel) + return -ENOMEM; + + ret = of_property_read_u32_index(cinfo->dev->of_node, "linaro,optee-channel-id", + 0, &channel_id); + if (ret) + return ret; + + cinfo->transport_info = channel; + channel->cinfo = cinfo; + channel->channel_id = channel_id; + mutex_init(&channel->mu); + + ret = setup_shmem(dev, cinfo, channel); + if (ret) + return ret; + + ret = open_session(scmi_optee_private, &channel->tee_session); + if (ret) + goto err_free_shm; + + ret = get_channel(channel); + if (ret) + goto err_close_sess; + + /* Enable polling */ + cinfo->no_completion_irq = true; + + mutex_lock(&scmi_optee_private->mu); + list_add(&channel->link, &scmi_optee_private->channel_list); + mutex_unlock(&scmi_optee_private->mu); + + return 0; + +err_close_sess: + close_session(scmi_optee_private, channel->tee_session); +err_free_shm: + if (channel->tee_shm) + tee_shm_free(channel->tee_shm); + + return ret; +} + +static int scmi_optee_chan_free(int id, void *p, void *data) +{ + struct scmi_chan_info *cinfo = p; + struct scmi_optee_channel *channel = cinfo->transport_info; + + mutex_lock(&scmi_optee_private->mu); + list_del(&channel->link); + mutex_unlock(&scmi_optee_private->mu); + + close_session(scmi_optee_private, channel->tee_session); + + if (channel->tee_shm) { + tee_shm_free(channel->tee_shm); + channel->tee_shm = NULL; + } + + cinfo->transport_info = NULL; + channel->cinfo = NULL; + + scmi_free_channel(cinfo, data, id); + + return 0; +} + +static struct scmi_shared_mem *get_channel_shm(struct scmi_optee_channel *chan, + struct scmi_xfer *xfer) +{ + if (!chan) + return NULL; + + return chan->shmem; +} + + +static int scmi_optee_send_message(struct scmi_chan_info *cinfo, + struct scmi_xfer *xfer) +{ + struct scmi_optee_channel *channel = cinfo->transport_info; + struct scmi_shared_mem *shmem = get_channel_shm(channel, xfer); + int ret; + + mutex_lock(&channel->mu); + shmem_tx_prepare(shmem, xfer); + + ret = invoke_process_smt_channel(channel); + if (ret) + mutex_unlock(&channel->mu); + + return ret; +} + +static void scmi_optee_fetch_response(struct scmi_chan_info *cinfo, + struct scmi_xfer *xfer) +{ + struct scmi_optee_channel *channel = cinfo->transport_info; + struct scmi_shared_mem *shmem = get_channel_shm(channel, xfer); + + shmem_fetch_response(shmem, xfer); +} + +static void scmi_optee_mark_txdone(struct scmi_chan_info *cinfo, int ret, + struct scmi_xfer *__unused) +{ + struct scmi_optee_channel *channel = cinfo->transport_info; + + mutex_unlock(&channel->mu); +} + +static struct scmi_transport_ops scmi_optee_ops = { + .link_supplier = scmi_optee_link_supplier, + .chan_available = scmi_optee_chan_available, + .chan_setup = scmi_optee_chan_setup, + .chan_free = scmi_optee_chan_free, + .send_message = scmi_optee_send_message, + .mark_txdone = scmi_optee_mark_txdone, + .fetch_response = scmi_optee_fetch_response, + .clear_channel = scmi_optee_clear_channel, +}; + +static int scmi_optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data) +{ + return ver->impl_id == TEE_IMPL_ID_OPTEE; +} + +static int scmi_optee_service_probe(struct device *dev) +{ + struct scmi_optee_agent *agent; + struct tee_context *tee_ctx; + int ret; + + /* Only one SCMI OP-TEE device allowed */ + if (scmi_optee_private) { + dev_err(dev, "An SCMI OP-TEE device was already initialized: only one allowed\n"); + return -EBUSY; + } + + tee_ctx = tee_client_open_context(NULL, scmi_optee_ctx_match, NULL, NULL); + if (IS_ERR(tee_ctx)) + return -ENODEV; + + agent = devm_kzalloc(dev, sizeof(*agent), GFP_KERNEL); + if (!agent) { + ret = -ENOMEM; + goto err; + } + + agent->dev = dev; + agent->tee_ctx = tee_ctx; + INIT_LIST_HEAD(&agent->channel_list); + mutex_init(&agent->mu); + + ret = get_capabilities(agent); + if (ret) + goto err; + + /* Ensure agent resources are all visible before scmi_optee_private is */ + smp_mb(); + scmi_optee_private = agent; + + return 0; + +err: + tee_client_close_context(tee_ctx); + + return ret; +} + +static int scmi_optee_service_remove(struct device *dev) +{ + struct scmi_optee_agent *agent = scmi_optee_private; + + if (!scmi_optee_private) + return -EINVAL; + + if (!list_empty(&scmi_optee_private->channel_list)) + return -EBUSY; + + /* Ensure cleared reference is visible before resources are released */ + smp_store_mb(scmi_optee_private, NULL); + + tee_client_close_context(agent->tee_ctx); + + return 0; +} + +static const struct tee_client_device_id scmi_optee_service_id[] = { + { + UUID_INIT(0xa8cfe406, 0xd4f5, 0x4a2e, + 0x9f, 0x8d, 0xa2, 0x5d, 0xc7, 0x54, 0xc0, 0x99) + }, + { } +}; + +MODULE_DEVICE_TABLE(tee, scmi_optee_service_id); + +static struct tee_client_driver scmi_optee_driver = { + .id_table = scmi_optee_service_id, + .driver = { + .name = "scmi-optee", + .bus = &tee_bus_type, + .probe = scmi_optee_service_probe, + .remove = scmi_optee_service_remove, + }, +}; + +static int scmi_optee_init(void) +{ + return driver_register(&scmi_optee_driver.driver); +} + +static void scmi_optee_exit(void) +{ + if (scmi_optee_private) + driver_unregister(&scmi_optee_driver.driver); +} + +const struct scmi_desc scmi_optee_desc = { + .transport_exit = scmi_optee_exit, + .ops = &scmi_optee_ops, + .max_rx_timeout_ms = 30, + .max_msg = 20, + .max_msg_size = SCMI_OPTEE_MAX_MSG_SIZE, + .sync_cmds_completed_on_ret = true, +}; diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c index 4effecc3bb46..745acfdd0b3d 100644 --- a/drivers/firmware/arm_scmi/smc.c +++ b/drivers/firmware/arm_scmi/smc.c @@ -7,6 +7,7 @@ */ #include <linux/arm-smccc.h> +#include <linux/atomic.h> #include <linux/device.h> #include <linux/err.h> #include <linux/interrupt.h> @@ -14,6 +15,7 @@ #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_irq.h> +#include <linux/processor.h> #include <linux/slab.h> #include "common.h" @@ -23,26 +25,29 @@ * * @cinfo: SCMI channel info * @shmem: Transmit/Receive shared memory area - * @shmem_lock: Lock to protect access to Tx/Rx shared memory area + * @shmem_lock: Lock to protect access to Tx/Rx shared memory area. + * Used when NOT operating in atomic mode. + * @inflight: Atomic flag to protect access to Tx/Rx shared memory area. + * Used when operating in atomic mode. * @func_id: smc/hvc call function id - * @irq: Optional; employed when platforms indicates msg completion by intr. - * @tx_complete: Optional, employed only when irq is valid. */ struct scmi_smc { struct scmi_chan_info *cinfo; struct scmi_shared_mem __iomem *shmem; + /* Protect access to shmem area */ struct mutex shmem_lock; +#define INFLIGHT_NONE MSG_TOKEN_MAX + atomic_t inflight; u32 func_id; - int irq; - struct completion tx_complete; }; static irqreturn_t smc_msg_done_isr(int irq, void *data) { struct scmi_smc *scmi_info = data; - complete(&scmi_info->tx_complete); + scmi_rx_callback(scmi_info->cinfo, + shmem_read_header(scmi_info->shmem), NULL); return IRQ_HANDLED; } @@ -57,6 +62,41 @@ static bool smc_chan_available(struct device *dev, int idx) return true; } +static inline void smc_channel_lock_init(struct scmi_smc *scmi_info) +{ + if (IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_SMC_ATOMIC_ENABLE)) + atomic_set(&scmi_info->inflight, INFLIGHT_NONE); + else + mutex_init(&scmi_info->shmem_lock); +} + +static bool smc_xfer_inflight(struct scmi_xfer *xfer, atomic_t *inflight) +{ + int ret; + + ret = atomic_cmpxchg(inflight, INFLIGHT_NONE, xfer->hdr.seq); + + return ret == INFLIGHT_NONE; +} + +static inline void +smc_channel_lock_acquire(struct scmi_smc *scmi_info, + struct scmi_xfer *xfer __maybe_unused) +{ + if (IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_SMC_ATOMIC_ENABLE)) + spin_until_cond(smc_xfer_inflight(xfer, &scmi_info->inflight)); + else + mutex_lock(&scmi_info->shmem_lock); +} + +static inline void smc_channel_lock_release(struct scmi_smc *scmi_info) +{ + if (IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_SMC_ATOMIC_ENABLE)) + atomic_set(&scmi_info->inflight, INFLIGHT_NONE); + else + mutex_unlock(&scmi_info->shmem_lock); +} + static int smc_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, bool tx) { @@ -111,13 +151,13 @@ static int smc_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, dev_err(dev, "failed to setup SCMI smc irq\n"); return ret; } - init_completion(&scmi_info->tx_complete); - scmi_info->irq = irq; + } else { + cinfo->no_completion_irq = true; } scmi_info->func_id = func_id; scmi_info->cinfo = cinfo; - mutex_init(&scmi_info->shmem_lock); + smc_channel_lock_init(scmi_info); cinfo->transport_info = scmi_info; return 0; @@ -142,26 +182,22 @@ static int smc_send_message(struct scmi_chan_info *cinfo, struct scmi_smc *scmi_info = cinfo->transport_info; struct arm_smccc_res res; - mutex_lock(&scmi_info->shmem_lock); + /* + * Channel will be released only once response has been + * surely fully retrieved, so after .mark_txdone() + */ + smc_channel_lock_acquire(scmi_info, xfer); shmem_tx_prepare(scmi_info->shmem, xfer); - if (scmi_info->irq) - reinit_completion(&scmi_info->tx_complete); - arm_smccc_1_1_invoke(scmi_info->func_id, 0, 0, 0, 0, 0, 0, 0, &res); - if (scmi_info->irq) - wait_for_completion(&scmi_info->tx_complete); - - scmi_rx_callback(scmi_info->cinfo, - shmem_read_header(scmi_info->shmem), NULL); - - mutex_unlock(&scmi_info->shmem_lock); - /* Only SMCCC_RET_NOT_SUPPORTED is valid error code */ - if (res.a0) + if (res.a0) { + smc_channel_lock_release(scmi_info); return -EOPNOTSUPP; + } + return 0; } @@ -173,12 +209,12 @@ static void smc_fetch_response(struct scmi_chan_info *cinfo, shmem_fetch_response(scmi_info->shmem, xfer); } -static bool -smc_poll_done(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer) +static void smc_mark_txdone(struct scmi_chan_info *cinfo, int ret, + struct scmi_xfer *__unused) { struct scmi_smc *scmi_info = cinfo->transport_info; - return shmem_poll_done(scmi_info->shmem, xfer); + smc_channel_lock_release(scmi_info); } static const struct scmi_transport_ops scmi_smc_ops = { @@ -186,8 +222,8 @@ static const struct scmi_transport_ops scmi_smc_ops = { .chan_setup = smc_chan_setup, .chan_free = smc_chan_free, .send_message = smc_send_message, + .mark_txdone = smc_mark_txdone, .fetch_response = smc_fetch_response, - .poll_done = smc_poll_done, }; const struct scmi_desc scmi_smc_desc = { @@ -195,4 +231,14 @@ const struct scmi_desc scmi_smc_desc = { .max_rx_timeout_ms = 30, .max_msg = 20, .max_msg_size = 128, + /* + * Setting .sync_cmds_atomic_replies to true for SMC assumes that, + * once the SMC instruction has completed successfully, the issued + * SCMI command would have been already fully processed by the SCMI + * platform firmware and so any possible response value expected + * for the issued command will be immmediately ready to be fetched + * from the shared memory area. + */ + .sync_cmds_completed_on_ret = true, + .atomic_enabled = IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_SMC_ATOMIC_ENABLE), }; diff --git a/drivers/firmware/arm_scmi/virtio.c b/drivers/firmware/arm_scmi/virtio.c index eefcc4146749..97d7cf53b774 100644 --- a/drivers/firmware/arm_scmi/virtio.c +++ b/drivers/firmware/arm_scmi/virtio.c @@ -95,7 +95,7 @@ static int scmi_vio_feed_vq_rx(struct scmi_vio_channel *vioch, rc = virtqueue_add_inbuf(vioch->vqueue, &sg_in, 1, msg, GFP_ATOMIC); if (rc) - dev_err_once(dev, "failed to add to virtqueue (%d)\n", rc); + dev_err(dev, "failed to add to RX virtqueue (%d)\n", rc); else virtqueue_kick(vioch->vqueue); @@ -193,8 +193,8 @@ static unsigned int virtio_get_max_msg(struct scmi_chan_info *base_cinfo) static int virtio_link_supplier(struct device *dev) { if (!scmi_vdev) { - dev_notice_once(dev, - "Deferring probe after not finding a bound scmi-virtio device\n"); + dev_notice(dev, + "Deferring probe after not finding a bound scmi-virtio device\n"); return -EPROBE_DEFER; } @@ -334,9 +334,8 @@ static int virtio_send_message(struct scmi_chan_info *cinfo, rc = virtqueue_add_sgs(vioch->vqueue, sgs, 1, 1, msg, GFP_ATOMIC); if (rc) { list_add(&msg->list, &vioch->free_list); - dev_err_once(vioch->cinfo->dev, - "%s() failed to add to virtqueue (%d)\n", __func__, - rc); + dev_err(vioch->cinfo->dev, + "failed to add to TX virtqueue (%d)\n", rc); } else { virtqueue_kick(vioch->vqueue); } @@ -427,10 +426,10 @@ static int scmi_vio_probe(struct virtio_device *vdev) sz /= DESCRIPTORS_PER_TX_MSG; if (sz > MSG_TOKEN_MAX) { - dev_info_once(dev, - "%s virtqueue could hold %d messages. Only %ld allowed to be pending.\n", - channels[i].is_rx ? "rx" : "tx", - sz, MSG_TOKEN_MAX); + dev_info(dev, + "%s virtqueue could hold %d messages. Only %ld allowed to be pending.\n", + channels[i].is_rx ? "rx" : "tx", + sz, MSG_TOKEN_MAX); sz = MSG_TOKEN_MAX; } channels[i].max_msg = sz; @@ -460,12 +459,13 @@ static void scmi_vio_remove(struct virtio_device *vdev) static int scmi_vio_validate(struct virtio_device *vdev) { +#ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO_VERSION1_COMPLIANCE if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) { dev_err(&vdev->dev, "device does not comply with spec version 1.x\n"); return -EINVAL; } - +#endif return 0; } |