On Wed, 2 Jun 2021 at 10:25, Peter Hilber <peter.hilber@xxxxxxxxxxxxxxx> wrote: > > 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 yes should work as well > 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 > >> > >> > > > >
