On 01.06.21 16:53, Vincent Guittot wrote: > On Tue, 11 May 2021 at 02:28, Peter Hilber <peter.hilber@xxxxxxxxxxxxxxx> wrote: >> >> From: Igor Skalkin <igor.skalkin@xxxxxxxxxxxxxxx> >> >> This transport enables accessing an SCMI platform as a virtio device. >> >> Implement an SCMI virtio driver according to the virtio SCMI device spec >> [1]. Virtio device id 32 has been reserved for the SCMI device [2]. >> >> The virtio transport has one Tx channel (virtio cmdq, A2P channel) and >> at most one Rx channel (virtio eventq, P2A channel). >> >> The following feature bit defined in [1] is not implemented: >> VIRTIO_SCMI_F_SHARED_MEMORY. >> >> After the preparatory patches, this implements the virtio transport as >> paraphrased: >> >> Only support a single arm-scmi device (which is consistent with the SCMI >> spec). scmi-virtio init is called from arm-scmi module init. During the >> arm-scmi probing, link to the first probed scmi-virtio device. Defer >> arm-scmi probing if no scmi-virtio device is bound yet. >> >> For simplicity, restrict the number of messages which can be pending >> simultaneously according to the virtqueue capacity. (The virtqueue sizes >> are negotiated with the virtio device.) >> >> As soon as Rx channel message buffers are allocated or have been read >> out by the arm-scmi driver, feed them to the virtio device. >> >> Since some virtio devices may not have the short response time exhibited >> by SCMI platforms using other transports, set a generous response >> timeout. >> >> Limitations: >> >> - Polling is not supported. >> >> - The timeout for delayed responses has not been adjusted. >> >> [1] https://github.com/oasis-tcs/virtio-spec/blob/master/virtio-scmi.tex >> [2] https://www.oasis-open.org/committees/ballot.php?id=3496 >> >> Signed-off-by: Igor Skalkin <igor.skalkin@xxxxxxxxxxxxxxx> >> [ Peter: Adapted patch for submission to upstream. ] >> Co-developed-by: Peter Hilber <peter.hilber@xxxxxxxxxxxxxxx> >> Signed-off-by: Peter Hilber <peter.hilber@xxxxxxxxxxxxxxx> >> --- >> MAINTAINERS | 1 + >> drivers/firmware/Kconfig | 12 + >> drivers/firmware/arm_scmi/Makefile | 1 + >> drivers/firmware/arm_scmi/common.h | 3 + >> drivers/firmware/arm_scmi/driver.c | 3 + >> drivers/firmware/arm_scmi/virtio.c | 523 +++++++++++++++++++++++++++++ >> include/uapi/linux/virtio_ids.h | 1 + >> include/uapi/linux/virtio_scmi.h | 25 ++ >> 8 files changed, 569 insertions(+) >> create mode 100644 drivers/firmware/arm_scmi/virtio.c >> create mode 100644 include/uapi/linux/virtio_scmi.h >> >> diff --git a/MAINTAINERS b/MAINTAINERS >> index bd7aff0c120f..449c336872f3 100644 >> --- a/MAINTAINERS >> +++ b/MAINTAINERS >> @@ -17705,6 +17705,7 @@ F: drivers/regulator/scmi-regulator.c >> F: drivers/reset/reset-scmi.c >> F: include/linux/sc[mp]i_protocol.h >> F: include/trace/events/scmi.h >> +F: include/uapi/linux/virtio_scmi.h >> >> SYSTEM RESET/SHUTDOWN DRIVERS >> M: Sebastian Reichel <sre@xxxxxxxxxx> >> diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig >> index e8377b12e4d0..7e9eafdd9b63 100644 >> --- a/drivers/firmware/Kconfig >> +++ b/drivers/firmware/Kconfig >> @@ -39,6 +39,18 @@ config ARM_SCMI_HAVE_MSG >> This declares whether a message passing based transport for SCMI is >> available. >> >> +# This config option includes the dependencies of ARM_SCMI_PROTOCOL so that >> +# this config doesn't show up when SCMI wouldn't be available. >> +config VIRTIO_SCMI >> + bool "Virtio transport for SCMI" >> + select ARM_SCMI_HAVE_MSG >> + depends on VIRTIO && (ARM || ARM64 || COMPILE_TEST) >> + help >> + This enables the virtio based transport for SCMI. >> + >> + If you want to use the ARM SCMI protocol between the virtio guest and >> + a host providing a virtio SCMI device, answer Y. >> + >> config ARM_SCMI_POWER_DOMAIN >> tristate "SCMI power domain driver" >> depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF) >> diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile >> index f6b4acb8abdb..db1787606fb2 100644 >> --- a/drivers/firmware/arm_scmi/Makefile >> +++ b/drivers/firmware/arm_scmi/Makefile >> @@ -5,6 +5,7 @@ scmi-transport-$(CONFIG_ARM_SCMI_HAVE_SHMEM) = shmem.o >> scmi-transport-$(CONFIG_MAILBOX) += mailbox.o >> scmi-transport-$(CONFIG_HAVE_ARM_SMCCC_DISCOVERY) += smc.o >> scmi-transport-$(CONFIG_ARM_SCMI_HAVE_MSG) += msg.o >> +scmi-transport-$(CONFIG_VIRTIO_SCMI) += virtio.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 4cb6571c7aaf..bada06cfd33d 100644 >> --- a/drivers/firmware/arm_scmi/common.h >> +++ b/drivers/firmware/arm_scmi/common.h >> @@ -349,6 +349,9 @@ extern const struct scmi_desc scmi_mailbox_desc; >> #ifdef CONFIG_HAVE_ARM_SMCCC >> extern const struct scmi_desc scmi_smc_desc; >> #endif >> +#ifdef CONFIG_VIRTIO_SCMI >> +extern const struct scmi_desc scmi_virtio_desc; >> +#endif >> >> int scmi_set_transport_info(struct device *dev, void *transport_info); >> void *scmi_get_transport_info(struct device *dev); >> diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c >> index e04e7c8e6928..a31187385470 100644 >> --- a/drivers/firmware/arm_scmi/driver.c >> +++ b/drivers/firmware/arm_scmi/driver.c >> @@ -1637,6 +1637,9 @@ static const struct of_device_id scmi_of_match[] = { >> #endif >> #ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY >> { .compatible = "arm,scmi-smc", .data = &scmi_smc_desc}, >> +#endif >> +#ifdef CONFIG_VIRTIO_SCMI >> + { .compatible = "arm,scmi-virtio", .data = &scmi_virtio_desc}, >> #endif >> { /* Sentinel */ }, >> }; >> diff --git a/drivers/firmware/arm_scmi/virtio.c b/drivers/firmware/arm_scmi/virtio.c >> new file mode 100644 >> index 000000000000..20972adf6dc7 >> --- /dev/null >> +++ b/drivers/firmware/arm_scmi/virtio.c >> @@ -0,0 +1,523 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Virtio Transport driver for Arm System Control and Management Interface >> + * (SCMI). >> + * >> + * Copyright (C) 2020 OpenSynergy. >> + */ >> + >> +/** >> + * DOC: Theory of Operation >> + * >> + * The scmi-virtio transport implements a driver for the virtio SCMI device. >> + * >> + * There is one Tx channel (virtio cmdq, A2P channel) and at most one Rx >> + * channel (virtio eventq, P2A channel). Each channel is implemented through a >> + * virtqueue. Access to each virtqueue is protected by spinlocks. >> + */ >> + >> +#include <linux/errno.h> >> +#include <linux/of.h> >> +#include <linux/of_platform.h> >> +#include <linux/platform_device.h> >> +#include <linux/module.h> >> +#include <linux/slab.h> >> +#include <linux/virtio.h> >> +#include <linux/virtio_config.h> >> +#include <uapi/linux/virtio_ids.h> >> +#include <uapi/linux/virtio_scmi.h> >> + >> +#include "common.h" >> + >> +#define VIRTIO_SCMI_MAX_MSG_SIZE 128 /* Value may be increased. */ >> +#define VIRTIO_SCMI_MAX_PDU_SIZE \ >> + (VIRTIO_SCMI_MAX_MSG_SIZE + SCMI_MSG_MAX_PROT_OVERHEAD) >> +#define DESCRIPTORS_PER_TX_MSG 2 >> + >> +/** >> + * struct scmi_vio_channel - Transport channel information >> + * >> + * @lock: Protects access to all members except ready. >> + * @ready_lock: Protects access to ready. If required, it must be taken before >> + * lock. >> + * @vqueue: Associated virtqueue >> + * @cinfo: SCMI Tx or Rx channel >> + * @free_list: List of unused scmi_vio_msg, maintained for Tx channels only >> + * @is_rx: Whether channel is an Rx channel >> + * @ready: Whether transport user is ready to hear about channel >> + */ >> +struct scmi_vio_channel { >> + spinlock_t lock; >> + spinlock_t ready_lock; >> + struct virtqueue *vqueue; >> + struct scmi_chan_info *cinfo; >> + struct list_head free_list; >> + u8 is_rx; >> + u8 ready; >> +}; >> + >> +/** >> + * struct scmi_vio_msg - Transport PDU information >> + * >> + * @request: SDU used for commands >> + * @input: SDU used for (delayed) responses and notifications >> + * @list: List which scmi_vio_msg may be part of >> + * @rx_len: Input SDU size in bytes, once input has been received >> + */ >> +struct scmi_vio_msg { >> + struct scmi_msg_payld *request; >> + struct scmi_msg_payld *input; >> + struct list_head list; >> + unsigned int rx_len; >> +}; >> + >> +static bool scmi_vio_have_vq_rx(struct virtio_device *vdev) >> +{ >> + return virtio_has_feature(vdev, VIRTIO_SCMI_F_P2A_CHANNELS); >> +} >> + >> +static int scmi_vio_feed_vq_rx(struct scmi_vio_channel *vioch, >> + struct scmi_vio_msg *msg) >> +{ >> + struct scatterlist sg_in; >> + int rc; >> + unsigned long flags; >> + >> + sg_init_one(&sg_in, msg->input, VIRTIO_SCMI_MAX_PDU_SIZE); >> + >> + spin_lock_irqsave(&vioch->lock, flags); >> + >> + rc = virtqueue_add_inbuf(vioch->vqueue, &sg_in, 1, msg, GFP_ATOMIC); >> + if (rc) >> + dev_err_once(vioch->cinfo->dev, >> + "%s() failed to add to virtqueue (%d)\n", __func__, >> + rc); >> + else >> + virtqueue_kick(vioch->vqueue); >> + >> + spin_unlock_irqrestore(&vioch->lock, flags); >> + >> + return rc; >> +} >> + >> +static void scmi_vio_complete_cb(struct virtqueue *vqueue) >> +{ >> + unsigned long ready_flags; >> + unsigned long flags; >> + unsigned int length; >> + struct scmi_vio_channel *vioch; >> + struct scmi_vio_msg *msg; >> + bool cb_enabled = true; >> + >> + if (WARN_ON_ONCE(!vqueue->vdev->priv)) >> + return; >> + vioch = &((struct scmi_vio_channel *)vqueue->vdev->priv)[vqueue->index]; >> + >> + for (;;) { >> + spin_lock_irqsave(&vioch->ready_lock, ready_flags); >> + >> + if (!vioch->ready) { >> + if (!cb_enabled) >> + (void)virtqueue_enable_cb(vqueue); >> + goto unlock_ready_out; >> + } >> + >> + spin_lock_irqsave(&vioch->lock, flags); >> + if (cb_enabled) { >> + virtqueue_disable_cb(vqueue); >> + cb_enabled = false; >> + } >> + msg = virtqueue_get_buf(vqueue, &length); >> + if (!msg) { >> + if (virtqueue_enable_cb(vqueue)) >> + goto unlock_out; >> + else >> + cb_enabled = true; >> + } >> + spin_unlock_irqrestore(&vioch->lock, flags); >> + >> + if (msg) { >> + msg->rx_len = length; >> + >> + /* >> + * Hold the ready_lock during the callback to avoid >> + * races when the arm-scmi driver is unbinding while >> + * the virtio device is not quiesced yet. >> + */ >> + scmi_rx_callback(vioch->cinfo, >> + msg_read_header(msg->input), msg); >> + } >> + spin_unlock_irqrestore(&vioch->ready_lock, ready_flags); >> + } >> + >> +unlock_out: >> + spin_unlock_irqrestore(&vioch->lock, flags); >> +unlock_ready_out: >> + spin_unlock_irqrestore(&vioch->ready_lock, ready_flags); >> +} >> + >> +static const char *const scmi_vio_vqueue_names[] = { "tx", "rx" }; >> + >> +static vq_callback_t *scmi_vio_complete_callbacks[] = { >> + scmi_vio_complete_cb, >> + scmi_vio_complete_cb >> +}; >> + >> +static unsigned int virtio_get_max_msg(bool tx, >> + struct scmi_chan_info *base_cinfo) >> +{ >> + struct scmi_vio_channel *vioch = base_cinfo->transport_info; >> + unsigned int ret; >> + >> + ret = virtqueue_get_vring_size(vioch->vqueue); >> + >> + /* Tx messages need multiple descriptors. */() >> + if (tx) >> + ret /= DESCRIPTORS_PER_TX_MSG; >> + >> + if (ret > MSG_TOKEN_MAX) { > > __scmi_xfer_info_init() returns error for info->max_msg >= > MSG_TOKEN_MAX so it should be (ret >= MSG_TOKEN_MAX > I think it would be better to use the > comparison in __scmi_xfer_info_init(), too. That should work in my understanding. I think that change was originally in my branch, but I lost it somehow. > >> + dev_info_once( >> + base_cinfo->dev, >> + "Only %ld messages can be pending simultaneously, while the %s virtqueue could hold %d\n", >> + MSG_TOKEN_MAX, tx ? "tx" : "rx", ret); >> + ret = MSG_TOKEN_MAX; > > should be ret = MSG_TOKEN_MAX-1; > >> + } >> + >> + return ret; >> +} >> + >> +static int scmi_vio_match_any_dev(struct device *dev, const void *data) >> +{ >> + return 1; >> +} >> + >> +static struct virtio_driver virtio_scmi_driver; /* Forward declaration */ >> + >> +static int virtio_link_supplier(struct device *dev) >> +{ >> + struct device *vdev = driver_find_device( >> + &virtio_scmi_driver.driver, NULL, NULL, scmi_vio_match_any_dev); >> + >> + if (!vdev) { >> + dev_notice_once( >> + dev, >> + "Deferring probe after not finding a bound scmi-virtio device\n"); >> + return -EPROBE_DEFER; >> + } >> + >> + /* Add device link for remove order and sysfs link. */ >> + if (!device_link_add(dev, vdev, DL_FLAG_AUTOREMOVE_CONSUMER)) { >> + put_device(vdev); >> + dev_err(dev, "Adding link to supplier virtio device failed\n"); >> + return -ECANCELED; >> + } >> + >> + put_device(vdev); >> + return scmi_set_transport_info(dev, dev_to_virtio(vdev)); >> +} >> + >> +static bool virtio_chan_available(struct device *dev, int idx) >> +{ >> + struct virtio_device *vdev; >> + >> + /* scmi-virtio doesn't support per-protocol channels */ >> + if (is_scmi_protocol_device(dev)) >> + return false; >> + >> + vdev = scmi_get_transport_info(dev); >> + if (!vdev) >> + return false; >> + >> + switch (idx) { >> + case VIRTIO_SCMI_VQ_TX: >> + return true; >> + case VIRTIO_SCMI_VQ_RX: >> + return scmi_vio_have_vq_rx(vdev); >> + default: >> + return false; >> + } >> +} >> + >> +static int virtio_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, >> + bool tx) >> +{ >> + unsigned long flags; >> + struct virtio_device *vdev; >> + struct scmi_vio_channel *vioch; >> + int index = tx ? VIRTIO_SCMI_VQ_TX : VIRTIO_SCMI_VQ_RX; >> + int max_msg; >> + int i; >> + >> + if (!virtio_chan_available(dev, index)) >> + return -ENODEV; >> + >> + vdev = scmi_get_transport_info(dev); >> + vioch = &((struct scmi_vio_channel *)vdev->priv)[index]; >> + >> + spin_lock_irqsave(&vioch->lock, flags); >> + cinfo->transport_info = vioch; >> + vioch->cinfo = cinfo; >> + spin_unlock_irqrestore(&vioch->lock, flags); >> + >> + max_msg = virtio_get_max_msg(tx, cinfo); >> + >> + for (i = 0; i < max_msg; i++) { >> + struct scmi_vio_msg *msg; >> + >> + msg = devm_kzalloc(cinfo->dev, sizeof(*msg), GFP_KERNEL); >> + if (!msg) >> + return -ENOMEM; >> + >> + if (tx) { >> + msg->request = devm_kzalloc(cinfo->dev, >> + VIRTIO_SCMI_MAX_PDU_SIZE, >> + GFP_KERNEL); >> + if (!msg->request) >> + return -ENOMEM; >> + } >> + >> + msg->input = devm_kzalloc(cinfo->dev, VIRTIO_SCMI_MAX_PDU_SIZE, >> + GFP_KERNEL); >> + if (!msg->input) >> + return -ENOMEM; >> + >> + if (tx) { >> + spin_lock_irqsave(&vioch->lock, flags); >> + list_add_tail(&msg->list, &vioch->free_list); >> + spin_unlock_irqrestore(&vioch->lock, flags); >> + } else { >> + scmi_vio_feed_vq_rx(vioch, msg); >> + } >> + } >> + >> + spin_lock_irqsave(&vioch->ready_lock, flags); >> + vioch->ready = true; >> + spin_unlock_irqrestore(&vioch->ready_lock, flags); >> + >> + return 0; >> +} >> + >> +static int virtio_chan_free(int id, void *p, void *data) >> +{ >> + unsigned long flags; >> + struct scmi_chan_info *cinfo = p; >> + struct scmi_vio_channel *vioch = cinfo->transport_info; >> + >> + spin_lock_irqsave(&vioch->ready_lock, flags); >> + vioch->ready = false; >> + spin_unlock_irqrestore(&vioch->ready_lock, flags); >> + >> + scmi_free_channel(cinfo, data, id); >> + return 0; >> +} >> + >> +static int virtio_send_message(struct scmi_chan_info *cinfo, >> + struct scmi_xfer *xfer) >> +{ >> + struct scmi_vio_channel *vioch = cinfo->transport_info; >> + struct scatterlist sg_out; >> + struct scatterlist sg_in; >> + struct scatterlist *sgs[DESCRIPTORS_PER_TX_MSG] = { &sg_out, &sg_in }; >> + unsigned long flags; >> + int rc; >> + struct scmi_vio_msg *msg; >> + >> + /* >> + * TODO: For now, we don't support polling. But it should not be >> + * difficult to add support. >> + */ >> + if (xfer->hdr.poll_completion) >> + return -EINVAL; >> + >> + spin_lock_irqsave(&vioch->lock, flags); >> + >> + if (list_empty(&vioch->free_list)) { >> + spin_unlock_irqrestore(&vioch->lock, flags); >> + return -EBUSY; >> + } >> + >> + msg = list_first_entry(&vioch->free_list, typeof(*msg), list); >> + list_del(&msg->list); >> + >> + msg_tx_prepare(msg->request, xfer); >> + >> + sg_init_one(&sg_out, msg->request, msg_command_size(xfer)); >> + sg_init_one(&sg_in, msg->input, msg_response_size(xfer)); >> + >> + 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); >> + } else { >> + virtqueue_kick(vioch->vqueue); >> + } >> + >> + spin_unlock_irqrestore(&vioch->lock, flags); >> + >> + return rc; >> +} >> + >> +static void virtio_fetch_response(struct scmi_chan_info *cinfo, >> + struct scmi_xfer *xfer, void *msg_handle) >> +{ >> + struct scmi_vio_msg *msg = msg_handle; >> + struct scmi_vio_channel *vioch = cinfo->transport_info; >> + >> + if (!msg) { >> + dev_dbg_once(&vioch->vqueue->vdev->dev, >> + "Ignoring %s() call with NULL msg_handle\n", >> + __func__); >> + return; >> + } >> + >> + msg_fetch_response(msg->input, msg->rx_len, xfer); >> +} >> + >> +static void virtio_fetch_notification(struct scmi_chan_info *cinfo, >> + size_t max_len, struct scmi_xfer *xfer, >> + void *msg_handle) >> +{ >> + struct scmi_vio_msg *msg = msg_handle; >> + struct scmi_vio_channel *vioch = cinfo->transport_info; >> + >> + if (!msg) { >> + dev_dbg_once(&vioch->vqueue->vdev->dev, >> + "Ignoring %s() call with NULL msg_handle\n", >> + __func__); >> + return; >> + } >> + >> + msg_fetch_notification(msg->input, msg->rx_len, max_len, xfer); >> +} >> + >> +static void dummy_clear_channel(struct scmi_chan_info *cinfo) >> +{ >> +} >> + >> +static bool dummy_poll_done(struct scmi_chan_info *cinfo, >> + struct scmi_xfer *xfer) >> +{ >> + return false; >> +} >> + >> +static void virtio_drop_message(struct scmi_chan_info *cinfo, void *msg_handle) >> +{ >> + unsigned long flags; >> + struct scmi_vio_channel *vioch = cinfo->transport_info; >> + struct scmi_vio_msg *msg = msg_handle; >> + >> + if (!msg) { >> + dev_dbg_once(&vioch->vqueue->vdev->dev, >> + "Ignoring %s() call with NULL msg_handle\n", >> + __func__); >> + return; >> + } >> + >> + if (vioch->is_rx) { >> + scmi_vio_feed_vq_rx(vioch, msg); >> + } else { >> + spin_lock_irqsave(&vioch->lock, flags); >> + list_add(&msg->list, &vioch->free_list); >> + spin_unlock_irqrestore(&vioch->lock, flags); >> + } >> +} >> + >> +static const struct scmi_transport_ops scmi_virtio_ops = { >> + .link_supplier = virtio_link_supplier, >> + .chan_available = virtio_chan_available, >> + .chan_setup = virtio_chan_setup, >> + .chan_free = virtio_chan_free, >> + .get_max_msg = virtio_get_max_msg, >> + .send_message = virtio_send_message, >> + .fetch_response = virtio_fetch_response, >> + .fetch_notification = virtio_fetch_notification, >> + .clear_channel = dummy_clear_channel, >> + .poll_done = dummy_poll_done, >> + .drop_message = virtio_drop_message, >> +}; >> + >> +static int scmi_vio_probe(struct virtio_device *vdev) >> +{ >> + struct device *dev = &vdev->dev; >> + struct scmi_vio_channel *channels; >> + bool have_vq_rx; >> + int vq_cnt; >> + int i; >> + int ret; >> + struct virtqueue *vqs[VIRTIO_SCMI_VQ_MAX_CNT]; >> + >> + have_vq_rx = scmi_vio_have_vq_rx(vdev); >> + vq_cnt = have_vq_rx ? VIRTIO_SCMI_VQ_MAX_CNT : 1; >> + >> + channels = devm_kcalloc(dev, vq_cnt, sizeof(*channels), GFP_KERNEL); >> + if (!channels) >> + return -ENOMEM; >> + >> + if (have_vq_rx) >> + channels[VIRTIO_SCMI_VQ_RX].is_rx = true; >> + >> + ret = virtio_find_vqs(vdev, vq_cnt, vqs, scmi_vio_complete_callbacks, >> + scmi_vio_vqueue_names, NULL); >> + if (ret) { >> + dev_err(dev, "Failed to get %d virtqueue(s)\n", vq_cnt); >> + return ret; >> + } >> + dev_info(dev, "Found %d virtqueue(s)\n", vq_cnt); >> + >> + for (i = 0; i < vq_cnt; i++) { >> + spin_lock_init(&channels[i].lock); >> + spin_lock_init(&channels[i].ready_lock); >> + INIT_LIST_HEAD(&channels[i].free_list); >> + channels[i].vqueue = vqs[i]; >> + } >> + >> + vdev->priv = channels; >> + >> + return 0; >> +} >> + >> +static void scmi_vio_remove(struct virtio_device *vdev) >> +{ >> + vdev->config->reset(vdev); >> + vdev->config->del_vqs(vdev); >> +} >> + >> +static unsigned int features[] = { >> + VIRTIO_SCMI_F_P2A_CHANNELS, >> +}; >> + >> +static const struct virtio_device_id id_table[] = { >> + { VIRTIO_ID_SCMI, VIRTIO_DEV_ANY_ID }, >> + { 0 } >> +}; >> + >> +static struct virtio_driver virtio_scmi_driver = { >> + .driver.name = "scmi-virtio", >> + .driver.owner = THIS_MODULE, >> + .feature_table = features, >> + .feature_table_size = ARRAY_SIZE(features), >> + .id_table = id_table, >> + .probe = scmi_vio_probe, >> + .remove = scmi_vio_remove, >> +}; >> + >> +static int __init virtio_scmi_init(void) >> +{ >> + return register_virtio_driver(&virtio_scmi_driver); >> +} >> + >> +static void __exit virtio_scmi_exit(void) >> +{ >> + unregister_virtio_driver(&virtio_scmi_driver); >> +} >> + >> +const struct scmi_desc scmi_virtio_desc = { >> + .init = virtio_scmi_init, >> + .exit = virtio_scmi_exit, >> + .ops = &scmi_virtio_ops, >> + .max_rx_timeout_ms = 60000, /* for non-realtime virtio devices */ >> + .max_msg = 0, /* overridden by virtio_get_max_msg() */ >> + .max_msg_size = VIRTIO_SCMI_MAX_MSG_SIZE, >> +}; >> diff --git a/include/uapi/linux/virtio_ids.h b/include/uapi/linux/virtio_ids.h >> index f0c35ce8628c..c146fe30e589 100644 >> --- a/include/uapi/linux/virtio_ids.h >> +++ b/include/uapi/linux/virtio_ids.h >> @@ -56,5 +56,6 @@ >> #define VIRTIO_ID_PMEM 27 /* virtio pmem */ >> #define VIRTIO_ID_BT 28 /* virtio bluetooth */ >> #define VIRTIO_ID_MAC80211_HWSIM 29 /* virtio mac80211-hwsim */ >> +#define VIRTIO_ID_SCMI 32 /* virtio SCMI */ >> >> #endif /* _LINUX_VIRTIO_IDS_H */ >> diff --git a/include/uapi/linux/virtio_scmi.h b/include/uapi/linux/virtio_scmi.h >> new file mode 100644 >> index 000000000000..732b01504c35 >> --- /dev/null >> +++ b/include/uapi/linux/virtio_scmi.h >> @@ -0,0 +1,25 @@ >> +/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */ >> +/* >> + * Copyright (C) 2020 OpenSynergy GmbH >> + */ >> + >> +#ifndef _UAPI_LINUX_VIRTIO_SCMI_H >> +#define _UAPI_LINUX_VIRTIO_SCMI_H >> + >> +#include <linux/virtio_types.h> >> + >> +/* Feature bits */ >> + >> +/* Device implements some SCMI notifications, or delayed responses. */ >> +#define VIRTIO_SCMI_F_P2A_CHANNELS 0 >> + >> +/* Device implements any SCMI statistics shared memory region */ >> +#define VIRTIO_SCMI_F_SHARED_MEMORY 1 >> + >> +/* Virtqueues */ >> + >> +#define VIRTIO_SCMI_VQ_TX 0 /* cmdq */ >> +#define VIRTIO_SCMI_VQ_RX 1 /* eventq */ >> +#define VIRTIO_SCMI_VQ_MAX_CNT 2 >> + >> +#endif /* _UAPI_LINUX_VIRTIO_SCMI_H */ >> -- >> 2.25.1 >> >> >
