// SPDX-License-Identifier: GPL-2.0-only#include <linux/module.h>#include <linux/virtio.h>#include <linux/virtio_config.h>#include <linux/input.h>#include <linux/slab.h>#include <linux/dma-mapping.h> #include <uapi/linux/virtio_ids.h>#include <uapi/linux/virtio_input.h>#include <linux/input/mt.h> struct virtio_input {	struct virtio_device       *vdev;	struct input_dev           *idev;	char                       name[64];	char                       serial[64];	char                       phys[64];	struct virtqueue           *evt, *sts;	__dma_from_device_group_begin();	struct virtio_input_event  evts[64];	__dma_from_device_group_end();	spinlock_t                 lock;	bool                       ready;}; static void virtinput_queue_evtbuf(struct virtio_input *vi,				   struct virtio_input_event *evtbuf){	struct scatterlist sg[1]; 	sg_init_one(sg, evtbuf, sizeof(*evtbuf));	virtqueue_add_inbuf_cache_clean(vi->evt, sg, 1, evtbuf, GFP_ATOMIC);} static void virtinput_recv_events(struct virtqueue *vq){	struct virtio_input *vi = vq->vdev->priv;	struct virtio_input_event *event;	unsigned long flags;	unsigned int len; 	spin_lock_irqsave(&vi->lock, flags);	if (vi->ready) {		while ((event = virtqueue_get_buf(vi->evt, &len)) != NULL) {			spin_unlock_irqrestore(&vi->lock, flags);			input_event(vi->idev,				    le16_to_cpu(event->type),				    le16_to_cpu(event->code),				    le32_to_cpu(event->value));			spin_lock_irqsave(&vi->lock, flags);			if (!vi->ready)				continue;			virtinput_queue_evtbuf(vi, event);		}		if (vi->ready)			virtqueue_kick(vq);	}	spin_unlock_irqrestore(&vi->lock, flags);} /* * On error we are losing the status update, which isn't critical as * this is typically used for stuff like keyboard leds. */static int virtinput_send_status(struct virtio_input *vi,				 u16 type, u16 code, s32 value){	struct virtio_input_event *stsbuf;	struct scatterlist sg[1];	unsigned long flags;	int rc; 	/*	 * Since 29cc309d8bf1 (HID: hid-multitouch: forward MSC_TIMESTAMP),	 * EV_MSC/MSC_TIMESTAMP is added to each before EV_SYN event.	 * EV_MSC is configured as INPUT_PASS_TO_ALL.	 * In case of touch device:	 *   BE pass EV_MSC/MSC_TIMESTAMP to FE on receiving event from evdev.	 *   FE pass EV_MSC/MSC_TIMESTAMP back to BE.	 *   BE writes EV_MSC/MSC_TIMESTAMP to evdev due to INPUT_PASS_TO_ALL.	 *   BE receives extra EV_MSC/MSC_TIMESTAMP and pass to FE.	 *   >>> Each new frame becomes larger and larger.	 * Disable EV_MSC/MSC_TIMESTAMP forwarding for MT.	 */	if (vi->idev->mt && type == EV_MSC && code == MSC_TIMESTAMP)		return 0; 	stsbuf = kzalloc_obj(*stsbuf, GFP_ATOMIC);	if (!stsbuf)		return -ENOMEM; 	stsbuf->type  = cpu_to_le16(type);	stsbuf->code  = cpu_to_le16(code);	stsbuf->value = cpu_to_le32(value);	sg_init_one(sg, stsbuf, sizeof(*stsbuf)); 	spin_lock_irqsave(&vi->lock, flags);	if (vi->ready) {		rc = virtqueue_add_outbuf(vi->sts, sg, 1, stsbuf, GFP_ATOMIC);		virtqueue_kick(vi->sts);	} else {		rc = -ENODEV;	}	spin_unlock_irqrestore(&vi->lock, flags); 	if (rc != 0)		kfree(stsbuf);	return rc;} static void virtinput_recv_status(struct virtqueue *vq){	struct virtio_input *vi = vq->vdev->priv;	struct virtio_input_event *stsbuf;	unsigned long flags;	unsigned int len; 	spin_lock_irqsave(&vi->lock, flags);	while ((stsbuf = virtqueue_get_buf(vi->sts, &len)) != NULL)		kfree(stsbuf);	spin_unlock_irqrestore(&vi->lock, flags);} static int virtinput_status(struct input_dev *idev, unsigned int type,			    unsigned int code, int value){	struct virtio_input *vi = input_get_drvdata(idev); 	return virtinput_send_status(vi, type, code, value);} static u8 virtinput_cfg_select(struct virtio_input *vi,			       u8 select, u8 subsel){	u8 size; 	virtio_cwrite_le(vi->vdev, struct virtio_input_config, select, &select);	virtio_cwrite_le(vi->vdev, struct virtio_input_config, subsel, &subsel);	virtio_cread_le(vi->vdev, struct virtio_input_config, size, &size);	return size;} static void virtinput_cfg_bits(struct virtio_input *vi, int select, int subsel,			       unsigned long *bits, unsigned int bitcount){	unsigned int bit;	u8 *virtio_bits;	u8 bytes; 	bytes = virtinput_cfg_select(vi, select, subsel);	if (!bytes)		return;	if (bitcount > bytes * 8)		bitcount = bytes * 8; 	/*	 * Bitmap in virtio config space is a simple stream of bytes,	 * with the first byte carrying bits 0-7, second bits 8-15 and	 * so on.	 */	virtio_bits = kzalloc(bytes, GFP_KERNEL);	if (!virtio_bits)		return;	virtio_cread_bytes(vi->vdev, offsetof(struct virtio_input_config,					      u.bitmap),			   virtio_bits, bytes);	for (bit = 0; bit < bitcount; bit++) {		if (virtio_bits[bit / 8] & (1 << (bit % 8)))			__set_bit(bit, bits);	}	kfree(virtio_bits); 	if (select == VIRTIO_INPUT_CFG_EV_BITS)		__set_bit(subsel, vi->idev->evbit);} static void virtinput_cfg_abs(struct virtio_input *vi, int abs){	u32 mi, ma, re, fu, fl; 	virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ABS_INFO, abs);	virtio_cread_le(vi->vdev, struct virtio_input_config, u.abs.min, &mi);	virtio_cread_le(vi->vdev, struct virtio_input_config, u.abs.max, &ma);	virtio_cread_le(vi->vdev, struct virtio_input_config, u.abs.res, &re);	virtio_cread_le(vi->vdev, struct virtio_input_config, u.abs.fuzz, &fu);	virtio_cread_le(vi->vdev, struct virtio_input_config, u.abs.flat, &fl);	input_set_abs_params(vi->idev, abs, mi, ma, fu, fl);	input_abs_set_res(vi->idev, abs, re);} static int virtinput_init_vqs(struct virtio_input *vi){	struct virtqueue_info vqs_info[] = {		{ "events", virtinput_recv_events },		{ "status", virtinput_recv_status },	};	struct virtqueue *vqs[2];	int err; 	err = virtio_find_vqs(vi->vdev, 2, vqs, vqs_info, NULL);	if (err)		return err;	vi->evt = vqs[0];	vi->sts = vqs[1]; 	return 0;} static void virtinput_fill_evt(struct virtio_input *vi){	unsigned long flags;	int i, size; 	spin_lock_irqsave(&vi->lock, flags);	size = virtqueue_get_vring_size(vi->evt);	if (size > ARRAY_SIZE(vi->evts))		size = ARRAY_SIZE(vi->evts);	for (i = 0; i < size; i++)		virtinput_queue_evtbuf(vi, &vi->evts[i]);	virtqueue_kick(vi->evt);	spin_unlock_irqrestore(&vi->lock, flags);} static int virtinput_probe(struct virtio_device *vdev){	struct virtio_input *vi;	unsigned long flags;	size_t size;	int abs, err, nslots; 	if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1))		return -ENODEV; 	vi = kzalloc_obj(*vi);	if (!vi)		return -ENOMEM; 	vdev->priv = vi;	vi->vdev = vdev;	spin_lock_init(&vi->lock); 	err = virtinput_init_vqs(vi);	if (err)		goto err_init_vq; 	vi->idev = input_allocate_device();	if (!vi->idev) {		err = -ENOMEM;		goto err_input_alloc;	}	input_set_drvdata(vi->idev, vi); 	size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_NAME, 0);	virtio_cread_bytes(vi->vdev, offsetof(struct virtio_input_config,					      u.string),			   vi->name, min(size, sizeof(vi->name)));	size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_SERIAL, 0);	virtio_cread_bytes(vi->vdev, offsetof(struct virtio_input_config,					      u.string),			   vi->serial, min(size, sizeof(vi->serial)));	snprintf(vi->phys, sizeof(vi->phys),		 "virtio%d/input0", vdev->index);	vi->idev->name = vi->name;	vi->idev->phys = vi->phys;	vi->idev->uniq = vi->serial; 	size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_DEVIDS, 0);	if (size >= sizeof(struct virtio_input_devids)) {		virtio_cread_le(vi->vdev, struct virtio_input_config,				u.ids.bustype, &vi->idev->id.bustype);		virtio_cread_le(vi->vdev, struct virtio_input_config,				u.ids.vendor, &vi->idev->id.vendor);		virtio_cread_le(vi->vdev, struct virtio_input_config,				u.ids.product, &vi->idev->id.product);		virtio_cread_le(vi->vdev, struct virtio_input_config,				u.ids.version, &vi->idev->id.version);	} else {		vi->idev->id.bustype = BUS_VIRTUAL;	} 	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_PROP_BITS, 0,			   vi->idev->propbit, INPUT_PROP_CNT);	size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_REP);	if (size)		__set_bit(EV_REP, vi->idev->evbit); 	vi->idev->dev.parent = &vdev->dev;	vi->idev->event = virtinput_status; 	/* device -> kernel */	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_KEY,			   vi->idev->keybit, KEY_CNT);	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_REL,			   vi->idev->relbit, REL_CNT);	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_ABS,			   vi->idev->absbit, ABS_CNT);	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_MSC,			   vi->idev->mscbit, MSC_CNT);	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_SW,			   vi->idev->swbit,  SW_CNT); 	/* kernel -> device */	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_LED,			   vi->idev->ledbit, LED_CNT);	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_SND,			   vi->idev->sndbit, SND_CNT); 	if (test_bit(EV_ABS, vi->idev->evbit)) {		for (abs = 0; abs < ABS_CNT; abs++) {			if (!test_bit(abs, vi->idev->absbit))				continue;			virtinput_cfg_abs(vi, abs);		} 		if (test_bit(ABS_MT_SLOT, vi->idev->absbit)) {			nslots = input_abs_get_max(vi->idev, ABS_MT_SLOT) + 1;			err = input_mt_init_slots(vi->idev, nslots, 0);			if (err)				goto err_mt_init_slots;		}	} 	virtio_device_ready(vdev);	vi->ready = true;	err = input_register_device(vi->idev);	if (err)		goto err_input_register; 	virtinput_fill_evt(vi);	return 0; err_input_register:	spin_lock_irqsave(&vi->lock, flags);	vi->ready = false;	spin_unlock_irqrestore(&vi->lock, flags);	virtio_reset_device(vdev);err_mt_init_slots:	input_free_device(vi->idev);err_input_alloc:	vdev->config->del_vqs(vdev);err_init_vq:	kfree(vi);	return err;} static void virtinput_remove(struct virtio_device *vdev){	struct virtio_input *vi = vdev->priv;	void *buf;	unsigned long flags; 	spin_lock_irqsave(&vi->lock, flags);	vi->ready = false;	spin_unlock_irqrestore(&vi->lock, flags); 	/* Callbacks use vi->idev. */	virtio_reset_device(vdev);	input_unregister_device(vi->idev);	while ((buf = virtqueue_detach_unused_buf(vi->sts)) != NULL)		kfree(buf);	vdev->config->del_vqs(vdev);	kfree(vi);} #ifdef CONFIG_PM_SLEEPstatic int virtinput_freeze(struct virtio_device *vdev){	struct virtio_input *vi = vdev->priv;	unsigned long flags;	void *buf; 	spin_lock_irqsave(&vi->lock, flags);	vi->ready = false;	spin_unlock_irqrestore(&vi->lock, flags); 	virtio_reset_device(vdev);	while ((buf = virtqueue_detach_unused_buf(vi->sts)) != NULL)		kfree(buf);	vdev->config->del_vqs(vdev);	return 0;} static int virtinput_restore(struct virtio_device *vdev){	struct virtio_input *vi = vdev->priv;	int err; 	err = virtinput_init_vqs(vi);	if (err)		return err; 	virtio_device_ready(vdev);	vi->ready = true;	virtinput_fill_evt(vi);	return 0;}#endif static unsigned int features[] = {	/* none */};static const struct virtio_device_id id_table[] = {	{ VIRTIO_ID_INPUT, VIRTIO_DEV_ANY_ID },	{ 0 },}; static struct virtio_driver virtio_input_driver = {	.driver.name         = KBUILD_MODNAME,	.feature_table       = features,	.feature_table_size  = ARRAY_SIZE(features),	.id_table            = id_table,	.probe               = virtinput_probe,	.remove              = virtinput_remove,#ifdef CONFIG_PM_SLEEP	.freeze	             = virtinput_freeze,	.restore             = virtinput_restore,#endif}; module_virtio_driver(virtio_input_driver);MODULE_DEVICE_TABLE(virtio, id_table); MODULE_LICENSE("GPL");MODULE_DESCRIPTION("Virtio input device driver");MODULE_AUTHOR("Gerd Hoffmann <kraxel@redhat.com>");