[PATCH v2 3/4] s390/kvm: Add a channel I/O based virtio transport driver.

Cornelia Huck
2012-09-04T15:13:41Z

Add a driver for kvm guests that matches virtual ccw devices provided
by the host as virtio bridge devices.

These virtio-ccw devices use a special set of channel commands in order
to perform virtio functions.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---

Changes v1->v2:
- adapt to improved virtio-ccw channel commands
- fix unregistration of online devices
- add a missing spinlock initialization

---
arch/s390/include/asm/irq.h | 1 +
arch/s390/kernel/irq.c | 1 +
drivers/s390/kvm/Makefile | 2 +-
drivers/s390/kvm/virtio_ccw.c | 790 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 793 insertions(+), 1 deletion(-)
create mode 100644 drivers/s390/kvm/virtio_ccw.c

diff --git a/arch/s390/include/asm/irq.h b/arch/s390/include/asm/irq.h
index 2b9d418..b4bea53 100644
--- a/arch/s390/include/asm/irq.h
+++ b/arch/s390/include/asm/irq.h
@@ -31,6 +31,7 @@ enum interruption_class {
IOINT_CTC,
IOINT_APB,
IOINT_CSC,
+ IOINT_VIR,
NMI_NMI,
NR_IRQS,
};
diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index dd7630d..2cc7eed 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -56,6 +56,7 @@ static const struct irq_class intrclass_names[] = {
{.name = "CTC", .desc = "[I/O] CTC" },
{.name = "APB", .desc = "[I/O] AP Bus" },
{.name = "CSC", .desc = "[I/O] CHSC Subchannel" },
+ {.name = "VIR", .desc = "[I/O] Virtual I/O Devices" },
{.name = "NMI", .desc = "[NMI] Machine Check" },
};

diff --git a/drivers/s390/kvm/Makefile b/drivers/s390/kvm/Makefile
index 0815690..241891a 100644
--- a/drivers/s390/kvm/Makefile
+++ b/drivers/s390/kvm/Makefile
@@ -6,4 +6,4 @@
# it under the terms of the GNU General Public License (version 2 only)
# as published by the Free Software Foundation.

-obj-$(CONFIG_S390_GUEST) += kvm_virtio.o
+obj-$(CONFIG_S390_GUEST) += kvm_virtio.o virtio_ccw.o
diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
new file mode 100644
index 0000000..1c9af22
--- /dev/null
+++ b/drivers/s390/kvm/virtio_ccw.c
@@ -0,0 +1,790 @@
+/*
+ * ccw based virtio transport
+ *
+ * Copyright IBM Corp. 2012
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2 only)
+ * as published by the Free Software Foundation.
+ *
+ * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
+ */
+
+#include <linux/kernel_stat.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/err.h>
+#include <linux/virtio.h>
+#include <linux/virtio_config.h>
+#include <linux/slab.h>
+#include <linux/virtio_console.h>
+#include <linux/interrupt.h>
+#include <linux/virtio_ring.h>
+#include <linux/pfn.h>
+#include <linux/async.h>
+#include <linux/wait.h>
+#include <linux/list.h>
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <asm/io.h>
+#include <asm/kvm_para.h>
+#include <asm/setup.h>
+#include <asm/irq.h>
+#include <asm/cio.h>
+#include <asm/ccwdev.h>
+
+/*
+ * virtio related functions
+ */
+
+struct vq_config_block {
+ __u16 index;
+ __u16 num;
+} __attribute__ ((packed));
+
+#define VIRTIO_CCW_CONFIG_SIZE 0x100
+/* same as PCI config space size, should be enough for all drivers */
+
+struct virtio_ccw_device {
+ struct virtio_device vdev;
+ __u8 status;
+ __u8 config[VIRTIO_CCW_CONFIG_SIZE];
+ struct ccw_device *cdev;
+ struct ccw1 ccw;
+ __u32 area;
+ __u32 curr_io;
+ int err;
+ wait_queue_head_t wait_q;
+ spinlock_t lock;
+ struct list_head virtqueues;
+ unsigned long indicators; /* XXX - works because we're under 64 bit */
+ struct vq_config_block *config_block;
+};
+
+struct vq_info_block {
+ __u64 queue;
+ __u32 align;
+ __u16 index;
+ __u16 num;
+} __attribute__ ((packed));
+
+struct virtio_feature_desc {
+ __u32 features;
+ __u8 index;
+} __attribute__ ((packed));
+
+struct virtio_ccw_vq_info {
+ struct virtqueue *vq;
+ int num;
+ int queue_index;
+ void *queue;
+ struct vq_info_block *info_block;
+ struct list_head node;
+};
+
+#define KVM_VIRTIO_CCW_RING_ALIGN 4096
+
+#define CCW_CMD_SET_VQ 0x13
+#define CCW_CMD_VDEV_RESET 0x33
+#define CCW_CMD_SET_IND 0x43
+#define CCW_CMD_READ_FEAT 0x12
+#define CCW_CMD_WRITE_FEAT 0x11
+#define CCW_CMD_READ_CONF 0x22
+#define CCW_CMD_WRITE_CONF 0x21
+#define CCW_CMD_WRITE_STATUS 0x31
+#define CCW_CMD_READ_VQ_CONF 0x32
+
+#define VIRTIO_CCW_DOING_SET_VQ 0x00010000
+#define VIRTIO_CCW_DOING_RESET 0x00040000
+#define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
+#define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
+#define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
+#define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
+#define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
+#define VIRTIO_CCW_DOING_SET_IND 0x01000000
+#define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
+#define VIRTIO_CCW_INTPARM_MASK 0xffff0000
+
+static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
+{
+ return container_of(vdev, struct virtio_ccw_device, vdev);
+}
+
+static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
+{
+ unsigned long flags;
+ __u32 ret;
+
+ spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
+ if (vcdev->err)
+ ret = vcdev->err;
+ else
+ ret = vcdev->curr_io & flag;
+ spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
+ return ret;
+}
+
+static int ccw_io_helper(struct virtio_ccw_device *vcdev, __u32 intparm)
+{
+ int ret;
+ unsigned long flags;
+ int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
+
+ spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
+ ret = ccw_device_start(vcdev->cdev, &vcdev->ccw, intparm, 0, 0);
+ if (!ret)
+ vcdev->curr_io |= flag;
+ spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
+ wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
+ return ret ? ret : vcdev->err;
+}
+
+static void virtio_ccw_kvm_notify(struct virtqueue *vq)
+{
+ struct virtio_ccw_vq_info *info = vq->priv;
+ struct virtio_ccw_device *vcdev;
+ struct subchannel_id schid;
+ __u32 reg2;
+
+ vcdev = to_vc_device(info->vq->vdev);
+ ccw_device_get_schid(vcdev->cdev, &schid);
+ reg2 = *(__u32 *)&schid;
+ kvm_hypercall2(3 /* CCW_NOTIFY */, reg2, info->queue_index);
+}
+
+static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev, int index)
+{
+ vcdev->config_block->index = index;
+ vcdev->ccw.cmd_code = CCW_CMD_READ_VQ_CONF;
+ vcdev->ccw.flags = 0;
+ vcdev->ccw.count = sizeof(struct vq_config_block);
+ vcdev->ccw.cda = (__u32)(unsigned long)(vcdev->config_block);
+ ccw_io_helper(vcdev, VIRTIO_CCW_DOING_READ_VQ_CONF);
+ return vcdev->config_block->num;
+}
+
+static void virtio_ccw_del_vq(struct virtqueue *vq)
+{
+ struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
+ struct virtio_ccw_vq_info *info = vq->priv;
+ unsigned long flags;
+ unsigned long size;
+ int ret;
+
+ /* Remove from our list. */
+ spin_lock_irqsave(&vcdev->lock, flags);
+ list_del(&info->node);
+ spin_unlock_irqrestore(&vcdev->lock, flags);
+
+ /* Release from host. */
+ info->info_block->queue = 0;
+ info->info_block->align = 0;
+ info->info_block->index = info->queue_index;
+ info->info_block->num = 0;
+ vcdev->ccw.cmd_code = CCW_CMD_SET_VQ;
+ vcdev->ccw.flags = 0;
+ vcdev->ccw.count = sizeof(*info->info_block);
+ vcdev->ccw.cda = (__u32)(unsigned long)(info->info_block);
+ ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_SET_VQ | info->queue_index);
+ if (ret)
+ dev_warn(&vq->vdev->dev, "Error %x while deleting queue %d",
+ ret, info->queue_index);
+
+ vring_del_virtqueue(vq);
+ size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
+ free_pages_exact(info->queue, size);
+ kfree(info->info_block);
+ kfree(info);
+}
+
+static void virtio_ccw_del_vqs(struct virtio_device *vdev)
+{
+ struct virtqueue *vq, *n;
+
+ list_for_each_entry_safe(vq, n, &vdev->vqs, list)
+ virtio_ccw_del_vq(vq);
+}
+
+static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
+ int i, vq_callback_t *callback,
+ const char *name)
+{
+ struct virtio_ccw_device *vcdev = to_vc_device(vdev);
+ int err;
+ struct virtqueue *vq;
+ struct virtio_ccw_vq_info *info;
+ unsigned long size;
+ unsigned long flags;
+
+ /* Allocate queue. */
+ info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
+ if (!info) {
+ dev_warn(&vcdev->cdev->dev, "no info\n");
+ err = -ENOMEM;
+ goto out_err;
+ }
+ info->info_block = kzalloc(sizeof(*info->info_block),
+ GFP_DMA | GFP_KERNEL);
+ if (!info->info_block) {
+ dev_warn(&vcdev->cdev->dev, "no info block\n");
+ err = -ENOMEM;
+ goto out_err;
+ }
+ info->queue_index = i;
+ info->num = virtio_ccw_read_vq_conf(vcdev, i);
+ size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
+ info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
+ if (info->queue == NULL) {
+ dev_warn(&vcdev->cdev->dev, "no queue\n");
+ err = -ENOMEM;
+ goto out_err;
+ }
+ vq = vring_new_virtqueue(info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev,
+ true, info->queue, virtio_ccw_kvm_notify,
+ callback, name);
+ if (!vq) {
+ /* For now, we fail if we can't get the requested size. */
+ dev_warn(&vcdev->cdev->dev, "no vq\n");
+ err = -ENOMEM;
+ free_pages_exact(info->queue, size);
+ goto out_err;
+ }
+ info->vq = vq;
+ vq->priv = info;
+
+ /* Register it with the host. */
+ info->info_block->queue = (__u64)info->queue;
+ info->info_block->align = KVM_VIRTIO_CCW_RING_ALIGN;
+ info->info_block->index = info->queue_index;
+ info->info_block->num = info->num;
+ vcdev->ccw.cmd_code = CCW_CMD_SET_VQ;
+ vcdev->ccw.flags = 0;
+ vcdev->ccw.count = sizeof(*info->info_block);
+ vcdev->ccw.cda = (__u32)(unsigned long)(info->info_block);
+ err = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_SET_VQ | info->queue_index);
+ if (err) {
+ dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
+ free_pages_exact(info->queue, size);
+ info->vq = NULL;
+ vq->priv = NULL;
+ goto out_err;
+ }
+
+ /* Save it to our list. */
+ spin_lock_irqsave(&vcdev->lock, flags);
+ list_add(&info->node, &vcdev->virtqueues);
+ spin_unlock_irqrestore(&vcdev->lock, flags);
+
+ return vq;
+
+out_err:
+ if (info)
+ kfree(info->info_block);
+ kfree(info);
+ return ERR_PTR(err);
+}
+
+static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
+ struct virtqueue *vqs[],
+ vq_callback_t *callbacks[],
+ const char *names[])
+{
+ struct virtio_ccw_device *vcdev = to_vc_device(vdev);
+ int ret, i;
+
+ for (i = 0; i < nvqs; ++i) {
+ vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i]);
+ if (IS_ERR(vqs[i])) {
+ ret = PTR_ERR(vqs[i]);
+ vqs[i] = NULL;
+ goto out;
+ }
+ }
+ /* Register queue indicators with host. */
+ vcdev->indicators = 0;
+ vcdev->ccw.cmd_code = CCW_CMD_SET_IND;
+ vcdev->ccw.flags = 0;
+ vcdev->ccw.count = sizeof(vcdev->indicators);
+ vcdev->ccw.cda = (__u32)(unsigned long)(&vcdev->indicators);
+ ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_SET_IND);
+ if (ret)
+ goto out;
+ return 0;
+out:
+ virtio_ccw_del_vqs(vdev);
+ return ret;
+}
+
+static void virtio_ccw_reset(struct virtio_device *vdev)
+{
+ struct virtio_ccw_device *vcdev = to_vc_device(vdev);
+
+ /* Send a reset ccw on device. */
+ vcdev->ccw.cmd_code = CCW_CMD_VDEV_RESET;
+ vcdev->ccw.flags = 0;
+ vcdev->ccw.count = 0;
+ vcdev->ccw.cda = 0;
+ ccw_io_helper(vcdev, VIRTIO_CCW_DOING_RESET);
+}
+
+static u32 virtio_ccw_get_features(struct virtio_device *vdev)
+{
+ struct virtio_ccw_device *vcdev = to_vc_device(vdev);
+ struct virtio_feature_desc features;
+ int ret;
+
+ /* Read the feature bits from the host. */
+ /* TODO: Features > 32 bits */
+ features.index = 0;
+ vcdev->ccw.cmd_code = CCW_CMD_READ_FEAT;
+ vcdev->ccw.flags = 0;
+ vcdev->ccw.count = sizeof(features);
+ vcdev->ccw.cda = vcdev->area;
+ ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_READ_FEAT);
+ if (ret)
+ return 0;
+
+ memcpy(&features, (void *)(unsigned long)vcdev->area,
+ sizeof(features));
+ return le32_to_cpu(features.features);
+}
+
+static void virtio_ccw_finalize_features(struct virtio_device *vdev)
+{
+ struct virtio_ccw_device *vcdev = to_vc_device(vdev);
+ struct virtio_feature_desc features;
+ int i;
+
+ /* Give virtio_ring a chance to accept features. */
+ vring_transport_features(vdev);
+
+ for (i = 0; i < sizeof(*vdev->features) / sizeof(features.features);
+ i++) {
+ features.index = i;
+ memcpy(&features.features,
+ vdev->features + i * sizeof(features.features),
+ sizeof(features.features));
+ memcpy((void *)(unsigned long)vcdev->area, &features,
+ sizeof(features));
+ /* Write the feature bits to the host. */
+ vcdev->ccw.cmd_code = CCW_CMD_WRITE_FEAT;
+ vcdev->ccw.flags = 0;
+ vcdev->ccw.count = sizeof(features);
+ vcdev->ccw.cda = vcdev->area;
+ ccw_io_helper(vcdev, VIRTIO_CCW_DOING_WRITE_FEAT);
+ }
+}
+
+static void virtio_ccw_get_config(struct virtio_device *vdev,
+ unsigned int offset, void *buf, unsigned len)
+{
+ struct virtio_ccw_device *vcdev = to_vc_device(vdev);
+ int ret;
+
+ /* Read the config area from the host. */
+ vcdev->ccw.cmd_code = CCW_CMD_READ_CONF;
+ vcdev->ccw.flags = 0;
+ vcdev->ccw.count = offset + len;
+ vcdev->ccw.cda = vcdev->area;
+ ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_READ_CONFIG);
+ if (ret)
+ return;
+
+ memcpy(vcdev->config, (void *)(unsigned long)vcdev->area,
+ sizeof(vcdev->config));
+ memcpy(buf, &vcdev->config[offset], len);
+}
+
+static void virtio_ccw_set_config(struct virtio_device *vdev,
+ unsigned int offset, const void *buf,
+ unsigned len)
+{
+ struct virtio_ccw_device *vcdev = to_vc_device(vdev);
+
+ memcpy(&vcdev->config[offset], buf, len);
+ /* Write the config area to the host. */
+ memcpy((void *)(unsigned long)vcdev->area, vcdev->config,
+ sizeof(vcdev->config));
+ vcdev->ccw.cmd_code = CCW_CMD_WRITE_CONF;
+ vcdev->ccw.flags = 0;
+ vcdev->ccw.count = offset + len;
+ vcdev->ccw.cda = vcdev->area;
+ ccw_io_helper(vcdev, VIRTIO_CCW_DOING_WRITE_CONFIG);
+}
+
+static u8 virtio_ccw_get_status(struct virtio_device *vdev)
+{
+ struct virtio_ccw_device *vcdev = to_vc_device(vdev);
+
+ return vcdev->status;
+}
+
+static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
+{
+ struct virtio_ccw_device *vcdev = to_vc_device(vdev);
+
+ /* Write the status to the host. */
+ vcdev->status = status;
+ memcpy((void *)(unsigned long)vcdev->area, &status, sizeof(status));
+ vcdev->ccw.cmd_code = CCW_CMD_WRITE_STATUS;
+ vcdev->ccw.flags = 0;
+ vcdev->ccw.count = sizeof(status);
+ vcdev->ccw.cda = vcdev->area;
+ ccw_io_helper(vcdev, VIRTIO_CCW_DOING_WRITE_STATUS);
+}
+
+static struct virtio_config_ops virtio_ccw_config_ops = {
+ .get_features = virtio_ccw_get_features,
+ .finalize_features = virtio_ccw_finalize_features,
+ .get = virtio_ccw_get_config,
+ .set = virtio_ccw_set_config,
+ .get_status = virtio_ccw_get_status,
+ .set_status = virtio_ccw_set_status,
+ .reset = virtio_ccw_reset,
+ .find_vqs = virtio_ccw_find_vqs,
+ .del_vqs = virtio_ccw_del_vqs,
+};
+
+
+/*
+ * ccw bus driver related functions
+ */
+
+static void virtio_ccw_release_dev(struct device *_d)
+{
+ struct virtio_device *dev = container_of(_d, struct virtio_device,
+ dev);
+ struct virtio_ccw_device *vcdev = to_vc_device(dev);
+
+ kfree((void *)(unsigned long)vcdev->area);
+ kfree(vcdev->config_block);
+ kfree(vcdev);
+}
+
+static int irb_is_error(struct irb *irb)
+{
+ if (scsw_cstat(&irb->scsw) != 0)
+ return 1;
+ if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
+ return 1;
+ if (scsw_cc(&irb->scsw) != 0)
+ return 1;
+ return 0;
+}
+
+static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
+ int index)
+{
+ struct virtio_ccw_vq_info *info;
+ unsigned long flags;
+ struct virtqueue *vq;
+
+ vq = NULL;
+ spin_lock_irqsave(&vcdev->lock, flags);
+ list_for_each_entry(info, &vcdev->virtqueues, node) {
+ if (info->queue_index == index) {
+ vq = info->vq;
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&vcdev->lock, flags);
+ return vq;
+}
+
+static void virtio_ccw_int_handler(struct ccw_device *cdev,
+ unsigned long intparm,
+ struct irb *irb)
+{
+ __u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
+ struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
+ int i;
+ struct virtqueue *vq;
+
+ /* Check if it's a notification from the host. */
+ if ((intparm == 0) &&
+ (scsw_stctl(&irb->scsw) ==
+ (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
+ /* OK */
+ }
+ if (irb_is_error(irb))
+ vcdev->err = -EIO; /* XXX - use real error */
+ if (vcdev->curr_io & activity) {
+ switch (activity) {
+ case VIRTIO_CCW_DOING_READ_FEAT:
+ case VIRTIO_CCW_DOING_WRITE_FEAT:
+ case VIRTIO_CCW_DOING_READ_CONFIG:
+ case VIRTIO_CCW_DOING_WRITE_CONFIG:
+ case VIRTIO_CCW_DOING_WRITE_STATUS:
+ case VIRTIO_CCW_DOING_SET_VQ:
+ case VIRTIO_CCW_DOING_SET_IND:
+ case VIRTIO_CCW_DOING_RESET:
+ case VIRTIO_CCW_DOING_READ_VQ_CONF:
+ vcdev->curr_io &= ~activity;
+ wake_up(&vcdev->wait_q);
+ break;
+ default:
+ /* don't know what to do... */
+ dev_warn(&cdev->dev, "Suspicious activity '%08x'\n",
+ activity);
+ WARN_ON(1);
+ break;
+ }
+ }
+ for_each_set_bit(i, &vcdev->indicators,
+ sizeof(vcdev->indicators)) {
+ vq = virtio_ccw_vq_by_ind(vcdev, i);
+ vring_interrupt(0, vq);
+ clear_bit(i, &vcdev->indicators);
+ }
+}
+
+/*
+ * We usually want to autoonline all devices, but give the admin
+ * a way to exempt devices from this.
+ */
+#define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
+ (8*sizeof(long)))
+static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
+
+static char *no_auto = "";
+
+module_param(no_auto, charp, 0444);
+MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
+
+static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
+{
+ struct ccw_dev_id id;
+
+ ccw_device_get_id(cdev, &id);
+ if (test_bit(id.devno, devs_no_auto[id.ssid]))
+ return 0;
+ return 1;
+}
+
+static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
+{
+ struct ccw_device *cdev = data;
+ int ret;
+
+ ret = ccw_device_set_online(cdev);
+ if (ret)
+ dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
+}
+
+static int virtio_ccw_probe(struct ccw_device *cdev)
+{
+ cdev->handler = virtio_ccw_int_handler;
+
+ if (virtio_ccw_check_autoonline(cdev))
+ async_schedule(virtio_ccw_auto_online, cdev);
+ return 0;
+}
+
+static void virtio_ccw_remove(struct ccw_device *cdev)
+{
+ struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
+
+ if (cdev->online) {
+ unregister_virtio_device(&vcdev->vdev);
+ dev_set_drvdata(&cdev->dev, NULL);
+ }
+ cdev->handler = NULL;
+}
+
+static int virtio_ccw_offline(struct ccw_device *cdev)
+{
+ struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
+
+ unregister_virtio_device(&vcdev->vdev);
+ dev_set_drvdata(&cdev->dev, NULL);
+ return 0;
+}
+
+
+/* Area needs to be big enough to fit status, features or configuration. */
+#define VIRTIO_AREA_SIZE VIRTIO_CCW_CONFIG_SIZE /* biggest possible use */
+
+static int virtio_ccw_online(struct ccw_device *cdev)
+{
+ int ret;
+ struct virtio_ccw_device *vcdev;
+
+ vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
+ if (!vcdev) {
+ dev_warn(&cdev->dev, "Could not get memory for virtio\n");
+ ret = -ENOMEM;
+ goto out_free;
+ }
+ vcdev->area = (__u32)(unsigned long)kzalloc(VIRTIO_AREA_SIZE,
+ GFP_DMA | GFP_KERNEL);
+ if (!vcdev->area) {
+ dev_warn(&cdev->dev, "Cound not get memory for virtio\n");
+ ret = -ENOMEM;
+ goto out_free;
+ }
+ vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
+ GFP_DMA | GFP_KERNEL);
+ if (!vcdev->config_block) {
+ ret = -ENOMEM;
+ goto out_free;
+ }
+ vcdev->vdev.dev.parent = &cdev->dev;
+ vcdev->vdev.dev.release = virtio_ccw_release_dev;
+ vcdev->vdev.config = &virtio_ccw_config_ops;
+ vcdev->cdev = cdev;
+ init_waitqueue_head(&vcdev->wait_q);
+ INIT_LIST_HEAD(&vcdev->virtqueues);
+ spin_lock_init(&vcdev->lock);
+
+ dev_set_drvdata(&cdev->dev, vcdev);
+ vcdev->vdev.id.vendor = cdev->id.cu_type;
+ vcdev->vdev.id.device = cdev->id.cu_model;
+ ret = register_virtio_device(&vcdev->vdev);
+ if (ret) {
+ dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
+ ret);
+ goto out_put;
+ }
+ return 0;
+out_put:
+ dev_set_drvdata(&cdev->dev, NULL);
+ put_device(&vcdev->vdev.dev);
+ return ret;
+out_free:
+ if (vcdev) {
+ kfree((void *)(unsigned long)vcdev->area);
+ kfree(vcdev->config_block);
+ }
+ kfree(vcdev);
+ return ret;
+}
+
+static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
+{
+ /* TODO: Check whether we need special handling here. */
+ return 0;
+}
+
+static struct ccw_device_id virtio_ids[] = {
+ { CCW_DEVICE(0x3832, 0) },
+ {},
+};
+MODULE_DEVICE_TABLE(ccw, virtio_ids);
+
+static struct ccw_driver virtio_ccw_driver = {
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "virtio_ccw",
+ },
+ .ids = virtio_ids,
+ .probe = virtio_ccw_probe,
+ .remove = virtio_ccw_remove,
+ .set_offline = virtio_ccw_offline,
+ .set_online = virtio_ccw_online,
+ .notify = virtio_ccw_cio_notify,
+ .int_class = IOINT_VIR,
+};
+
+static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
+ int max_digit, int max_val)
+{
+ int diff;
+
+ diff = 0;
+ *val = 0;
+
+ while (diff <= max_digit) {
+ int value = hex_to_bin(**cp);
+
+ if (value < 0)
+ break;
+ *val = *val * 16 + value;
+ (*cp)++;
+ diff++;
+ }
+
+ if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
+ return 1;
+
+ return 0;
+}
+
+static int __init parse_busid(char *str, unsigned int *cssid,
+ unsigned int *ssid, unsigned int *devno)
+{
+ char *str_work;
+ int rc, ret;
+
+ rc = 1;
+
+ if (*str == '\0')
+ goto out;
+
+ str_work = str;
+ ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
+ if (ret || (str_work[0] != '.'))
+ goto out;
+ str_work++;
+ ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
+ if (ret || (str_work[0] != '.'))
+ goto out;
+ str_work++;
+ ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
+ if (ret || (str_work[0] != '\0'))
+ goto out;
+
+ rc = 0;
+out:
+ return rc;
+}
+
+static void __init no_auto_parse(void)
+{
+ unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
+ char *parm, *str;
+ int rc;
+
+ str = no_auto;
+ while ((parm = strsep(&str, ","))) {
+ rc = parse_busid(strsep(&parm, "-"), &from_cssid,
+ &from_ssid, &from);
+ if (rc)
+ continue;
+ if (parm != NULL) {
+ rc = parse_busid(parm, &to_cssid,
+ &to_ssid, &to);
+ if ((from_ssid > to_ssid) ||
+ ((from_ssid == to_ssid) && (from > to)))
+ rc = -EINVAL;
+ } else {
+ to_cssid = from_cssid;
+ to_ssid = from_ssid;
+ to = from;
+ }
+ if (rc)
+ continue;
+ while ((from_ssid < to_ssid) ||
+ ((from_ssid == to_ssid) && (from <= to))) {
+ set_bit(from, devs_no_auto[from_ssid]);
+ from++;
+ if (from > __MAX_SUBCHANNEL) {
+ from_ssid++;
+ from = 0;
+ }
+ }
+ }
+}
+
+static int __init virtio_ccw_init(void)
+{
+ /* parse no_auto string before we do anything further */
+ no_auto_parse();
+ return ccw_driver_register(&virtio_ccw_driver);
+}
+module_init(virtio_ccw_init);
+
+static void __exit virtio_ccw_exit(void)
+{
+ ccw_driver_unregister(&virtio_ccw_driver);
+}
+module_exit(virtio_ccw_exit);
--
1.7.11.5