--- /dev/null
+/*
+ * Intel MIC Platform Software Stack (MPSS)
+ *
+ * Copyright(c) 2013 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ * Disclaimer: The codes contained in these modules may be specific to
+ * the Intel Software Development Platform codenamed: Knights Ferry, and
+ * the Intel product codenamed: Knights Corner, and are not backward
+ * compatible with other Intel products. Additionally, Intel will NOT
+ * support the codes or instruction set in future products.
+ *
+ * Adapted from:
+ *
+ * virtio for kvm on s390
+ *
+ * Copyright IBM Corp. 2008
+ *
+ * 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): Christian Borntraeger <borntraeger@de.ibm.com>
+ *
+ * Intel MIC Card driver.
+ *
+ */
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/virtio_config.h>
+
+#include "../common/mic_device.h"
+#include "mic_virtio.h"
+
+#define VIRTIO_SUBCODE_64 0x0D00
+
+#define MIC_MAX_VRINGS 4
+struct mic_vdev {
+ struct virtio_device vdev;
+ struct mic_device_desc __iomem *desc;
+ struct mic_device_ctrl __iomem *dc;
+ struct mic_device *mdev;
+ void __iomem *vr[MIC_MAX_VRINGS];
+ int used_size[MIC_MAX_VRINGS];
+ struct completion reset_done;
+ struct mic_irq *virtio_cookie;
+ int c2h_vdev_db;
+};
+
+static struct mic_irq *virtio_config_cookie;
+#define to_micvdev(vd) container_of(vd, struct mic_vdev, vdev)
+
+/* Helper API to obtain the parent of the virtio device */
+static inline struct device *mic_dev(struct mic_vdev *mvdev)
+{
+ return mvdev->vdev.dev.parent;
+}
+
+/* This gets the device's feature bits. */
+static u32 mic_get_features(struct virtio_device *vdev)
+{
+ unsigned int i, bits;
+ u32 features = 0;
+ struct mic_device_desc __iomem *desc = to_micvdev(vdev)->desc;
+ u8 __iomem *in_features = mic_vq_features(desc);
+ int feature_len = ioread8(&desc->feature_len);
+
+ bits = min_t(unsigned, feature_len,
+ sizeof(vdev->features)) * 8;
+ for (i = 0; i < bits; i++)
+ if (ioread8(&in_features[i / 8]) & (BIT(i % 8)))
+ features |= BIT(i);
+
+ return features;
+}
+
+static void mic_finalize_features(struct virtio_device *vdev)
+{
+ unsigned int i, bits;
+ struct mic_device_desc __iomem *desc = to_micvdev(vdev)->desc;
+ u8 feature_len = ioread8(&desc->feature_len);
+ /* Second half of bitmap is features we accept. */
+ u8 __iomem *out_features =
+ mic_vq_features(desc) + feature_len;
+
+ /* Give virtio_ring a chance to accept features. */
+ vring_transport_features(vdev);
+
+ memset_io(out_features, 0, feature_len);
+ bits = min_t(unsigned, feature_len,
+ sizeof(vdev->features)) * 8;
+ for (i = 0; i < bits; i++) {
+ if (test_bit(i, vdev->features))
+ iowrite8(ioread8(&out_features[i / 8]) | (1 << (i % 8)),
+ &out_features[i / 8]);
+ }
+}
+
+/*
+ * Reading and writing elements in config space
+ */
+static void mic_get(struct virtio_device *vdev, unsigned int offset,
+ void *buf, unsigned len)
+{
+ struct mic_device_desc __iomem *desc = to_micvdev(vdev)->desc;
+
+ if (offset + len > ioread8(&desc->config_len))
+ return;
+ memcpy_fromio(buf, mic_vq_configspace(desc) + offset, len);
+}
+
+static void mic_set(struct virtio_device *vdev, unsigned int offset,
+ const void *buf, unsigned len)
+{
+ struct mic_device_desc __iomem *desc = to_micvdev(vdev)->desc;
+
+ if (offset + len > ioread8(&desc->config_len))
+ return;
+ memcpy_toio(mic_vq_configspace(desc) + offset, buf, len);
+}
+
+/*
+ * The operations to get and set the status word just access the status
+ * field of the device descriptor. set_status also interrupts the host
+ * to tell about status changes.
+ */
+static u8 mic_get_status(struct virtio_device *vdev)
+{
+ return ioread8(&to_micvdev(vdev)->desc->status);
+}
+
+static void mic_set_status(struct virtio_device *vdev, u8 status)
+{
+ struct mic_vdev *mvdev = to_micvdev(vdev);
+ if (!status)
+ return;
+ iowrite8(status, &mvdev->desc->status);
+ mic_send_intr(mvdev->mdev, mvdev->c2h_vdev_db);
+}
+
+/* Inform host on a virtio device reset and wait for ack from host */
+static void mic_reset_inform_host(struct virtio_device *vdev)
+{
+ struct mic_vdev *mvdev = to_micvdev(vdev);
+ struct mic_device_ctrl __iomem *dc = mvdev->dc;
+ int retry = 100, i;
+
+ iowrite8(0, &dc->host_ack);
+ iowrite8(1, &dc->vdev_reset);
+ mic_send_intr(mvdev->mdev, mvdev->c2h_vdev_db);
+
+ /* Wait till host completes all card accesses and acks the reset */
+ for (i = retry; i--;) {
+ if (ioread8(&dc->host_ack))
+ break;
+ msleep(100);
+ };
+
+ dev_dbg(mic_dev(mvdev), "%s: retry: %d\n", __func__, retry);
+
+ /* Reset status to 0 in case we timed out */
+ iowrite8(0, &mvdev->desc->status);
+}
+
+static void mic_reset(struct virtio_device *vdev)
+{
+ struct mic_vdev *mvdev = to_micvdev(vdev);
+
+ dev_dbg(mic_dev(mvdev), "%s: virtio id %d\n",
+ __func__, vdev->id.device);
+
+ mic_reset_inform_host(vdev);
+ complete_all(&mvdev->reset_done);
+}
+
+/*
+ * The virtio_ring code calls this API when it wants to notify the Host.
+ */
+static void mic_notify(struct virtqueue *vq)
+{
+ struct mic_vdev *mvdev = vq->priv;
+
+ mic_send_intr(mvdev->mdev, mvdev->c2h_vdev_db);
+}
+
+static void mic_del_vq(struct virtqueue *vq, int n)
+{
+ struct mic_vdev *mvdev = to_micvdev(vq->vdev);
+ struct vring *vr = (struct vring *) (vq + 1);
+
+ free_pages((unsigned long) vr->used,
+ get_order(mvdev->used_size[n]));
+ vring_del_virtqueue(vq);
+ mic_card_unmap(mvdev->mdev, mvdev->vr[n]);
+ mvdev->vr[n] = NULL;
+}
+
+static void mic_del_vqs(struct virtio_device *vdev)
+{
+ struct mic_vdev *mvdev = to_micvdev(vdev);
+ struct virtqueue *vq, *n;
+ int idx = 0;
+
+ dev_dbg(mic_dev(mvdev), "%s\n", __func__);
+
+ list_for_each_entry_safe(vq, n, &vdev->vqs, list)
+ mic_del_vq(vq, idx++);
+}
+
+/*
+ * This routine will assign vring's allocated in host/io memory. Code in
+ * virtio_ring.c however continues to access this io memory as if it were local
+ * memory without io accessors.
+ */
+static struct virtqueue *mic_find_vq(struct virtio_device *vdev,
+ unsigned index,
+ void (*callback)(struct virtqueue *vq),
+ const char *name)
+{
+ struct mic_vdev *mvdev = to_micvdev(vdev);
+ struct mic_vqconfig __iomem *vqconfig;
+ struct mic_vqconfig config;
+ struct virtqueue *vq;
+ void __iomem *va;
+ struct _mic_vring_info __iomem *info;
+ void *used;
+ int vr_size, _vr_size, err, magic;
+ struct vring *vr;
+ u8 type = ioread8(&mvdev->desc->type);
+
+ if (index >= ioread8(&mvdev->desc->num_vq))
+ return ERR_PTR(-ENOENT);
+
+ if (!name)
+ return ERR_PTR(-ENOENT);
+
+ /* First assign the vring's allocated in host memory */
+ vqconfig = mic_vq_config(mvdev->desc) + index;
+ memcpy_fromio(&config, vqconfig, sizeof(config));
+ _vr_size = vring_size(config.num, MIC_VIRTIO_RING_ALIGN);
+ vr_size = PAGE_ALIGN(_vr_size + sizeof(struct _mic_vring_info));
+ va = mic_card_map(mvdev->mdev, config.address, vr_size);
+ if (!va)
+ return ERR_PTR(-ENOMEM);
+ mvdev->vr[index] = va;
+ memset_io(va, 0x0, _vr_size);
+ vq = vring_new_virtqueue(index,
+ config.num, MIC_VIRTIO_RING_ALIGN, vdev,
+ false,
+ va, mic_notify, callback, name);
+ if (!vq) {
+ err = -ENOMEM;
+ goto unmap;
+ }
+ info = va + _vr_size;
+ magic = ioread32(&info->magic);
+
+ if (WARN(magic != MIC_MAGIC + type + index, "magic mismatch")) {
+ err = -EIO;
+ goto unmap;
+ }
+
+ /* Allocate and reassign used ring now */
+ mvdev->used_size[index] = PAGE_ALIGN(sizeof(__u16) * 3 +
+ sizeof(struct vring_used_elem) * config.num);
+ used = (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
+ get_order(mvdev->used_size[index]));
+ if (!used) {
+ err = -ENOMEM;
+ dev_err(mic_dev(mvdev), "%s %d err %d\n",
+ __func__, __LINE__, err);
+ goto del_vq;
+ }
+ iowrite64(virt_to_phys(used), &vqconfig->used_address);
+
+ /*
+ * To reassign the used ring here we are directly accessing
+ * struct vring_virtqueue which is a private data structure
+ * in virtio_ring.c. At the minimum, a BUILD_BUG_ON() in
+ * vring_new_virtqueue() would ensure that
+ * (&vq->vring == (struct vring *) (&vq->vq + 1));
+ */
+ vr = (struct vring *) (vq + 1);
+ vr->used = used;
+
+ vq->priv = mvdev;
+ return vq;
+del_vq:
+ vring_del_virtqueue(vq);
+unmap:
+ mic_card_unmap(mvdev->mdev, mvdev->vr[index]);
+ return ERR_PTR(err);
+}
+
+static int mic_find_vqs(struct virtio_device *vdev, unsigned nvqs,
+ struct virtqueue *vqs[],
+ vq_callback_t *callbacks[],
+ const char *names[])
+{
+ struct mic_vdev *mvdev = to_micvdev(vdev);
+ struct mic_device_ctrl __iomem *dc = mvdev->dc;
+ int i, err, retry = 100;
+
+ /* We must have this many virtqueues. */
+ if (nvqs > ioread8(&mvdev->desc->num_vq))
+ return -ENOENT;
+
+ for (i = 0; i < nvqs; ++i) {
+ dev_dbg(mic_dev(mvdev), "%s: %d: %s\n",
+ __func__, i, names[i]);
+ vqs[i] = mic_find_vq(vdev, i, callbacks[i], names[i]);
+ if (IS_ERR(vqs[i])) {
+ err = PTR_ERR(vqs[i]);
+ goto error;
+ }
+ }
+
+ iowrite8(1, &dc->used_address_updated);
+ /*
+ * Send an interrupt to the host to inform it that used
+ * rings have been re-assigned.
+ */
+ mic_send_intr(mvdev->mdev, mvdev->c2h_vdev_db);
+ for (i = retry; i--;) {
+ if (!ioread8(&dc->used_address_updated))
+ break;
+ msleep(100);
+ };
+
+ dev_dbg(mic_dev(mvdev), "%s: retry: %d\n", __func__, retry);
+ if (!retry) {
+ err = -ENODEV;
+ goto error;
+ }
+
+ return 0;
+error:
+ mic_del_vqs(vdev);
+ return err;
+}
+
+/*
+ * The config ops structure as defined by virtio config
+ */
+static struct virtio_config_ops mic_vq_config_ops = {
+ .get_features = mic_get_features,
+ .finalize_features = mic_finalize_features,
+ .get = mic_get,
+ .set = mic_set,
+ .get_status = mic_get_status,
+ .set_status = mic_set_status,
+ .reset = mic_reset,
+ .find_vqs = mic_find_vqs,
+ .del_vqs = mic_del_vqs,
+};
+
+static irqreturn_t
+mic_virtio_intr_handler(int irq, void *data)
+{
+ struct mic_vdev *mvdev = data;
+ struct virtqueue *vq;
+
+ mic_ack_interrupt(mvdev->mdev);
+ list_for_each_entry(vq, &mvdev->vdev.vqs, list)
+ vring_interrupt(0, vq);
+
+ return IRQ_HANDLED;
+}
+
+static void mic_virtio_release_dev(struct device *_d)
+{
+ /*
+ * No need for a release method similar to virtio PCI.
+ * Provide an empty one to avoid getting a warning from core.
+ */
+}
+
+/*
+ * adds a new device and register it with virtio
+ * appropriate drivers are loaded by the device model
+ */
+static int mic_add_device(struct mic_device_desc __iomem *d,
+ unsigned int offset, struct mic_driver *mdrv)
+{
+ struct mic_vdev *mvdev;
+ int ret;
+ int virtio_db;
+ u8 type = ioread8(&d->type);
+
+ mvdev = kzalloc(sizeof(*mvdev), GFP_KERNEL);
+ if (!mvdev) {
+ dev_err(mdrv->dev, "Cannot allocate mic dev %u type %u\n",
+ offset, type);
+ return -ENOMEM;
+ }
+
+ mvdev->mdev = &mdrv->mdev;
+ mvdev->vdev.dev.parent = mdrv->dev;
+ mvdev->vdev.dev.release = mic_virtio_release_dev;
+ mvdev->vdev.id.device = type;
+ mvdev->vdev.config = &mic_vq_config_ops;
+ mvdev->desc = d;
+ mvdev->dc = (void __iomem *)d + mic_aligned_desc_size(d);
+ init_completion(&mvdev->reset_done);
+
+ virtio_db = mic_next_card_db();
+ mvdev->virtio_cookie = mic_request_card_irq(mic_virtio_intr_handler,
+ "virtio intr", mvdev, virtio_db);
+ if (IS_ERR(mvdev->virtio_cookie)) {
+ ret = PTR_ERR(mvdev->virtio_cookie);
+ goto kfree;
+ }
+ iowrite8((u8)virtio_db, &mvdev->dc->h2c_vdev_db);
+ mvdev->c2h_vdev_db = ioread8(&mvdev->dc->c2h_vdev_db);
+
+ ret = register_virtio_device(&mvdev->vdev);
+ if (ret) {
+ dev_err(mic_dev(mvdev),
+ "Failed to register mic device %u type %u\n",
+ offset, type);
+ goto free_irq;
+ }
+ iowrite64((u64)mvdev, &mvdev->dc->vdev);
+ dev_dbg(mic_dev(mvdev), "%s: registered mic device %u type %u mvdev %p\n",
+ __func__, offset, type, mvdev);
+
+ return 0;
+
+free_irq:
+ mic_free_card_irq(mvdev->virtio_cookie, mvdev);
+kfree:
+ kfree(mvdev);
+ return ret;
+}
+
+/*
+ * match for a mic device with a specific desc pointer
+ */
+static int mic_match_desc(struct device *dev, void *data)
+{
+ struct virtio_device *vdev = dev_to_virtio(dev);
+ struct mic_vdev *mvdev = to_micvdev(vdev);
+
+ return mvdev->desc == (void __iomem *)data;
+}
+
+static void mic_handle_config_change(struct mic_device_desc __iomem *d,
+ unsigned int offset, struct mic_driver *mdrv)
+{
+ struct mic_device_ctrl __iomem *dc
+ = (void __iomem *)d + mic_aligned_desc_size(d);
+ struct mic_vdev *mvdev = (struct mic_vdev *)ioread64(&dc->vdev);
+ struct virtio_driver *drv;
+
+ if (ioread8(&dc->config_change) != MIC_VIRTIO_PARAM_CONFIG_CHANGED)
+ return;
+
+ dev_dbg(mdrv->dev, "%s %d\n", __func__, __LINE__);
+ drv = container_of(mvdev->vdev.dev.driver,
+ struct virtio_driver, driver);
+ if (drv->config_changed)
+ drv->config_changed(&mvdev->vdev);
+ iowrite8(1, &dc->guest_ack);
+}
+
+/*
+ * removes a virtio device if a hot remove event has been
+ * requested by the host.
+ */
+static int mic_remove_device(struct mic_device_desc __iomem *d,
+ unsigned int offset, struct mic_driver *mdrv)
+{
+ struct mic_device_ctrl __iomem *dc
+ = (void __iomem *)d + mic_aligned_desc_size(d);
+ struct mic_vdev *mvdev = (struct mic_vdev *)ioread64(&dc->vdev);
+ u8 status;
+ int ret = -1;
+
+ if (ioread8(&dc->config_change) == MIC_VIRTIO_PARAM_DEV_REMOVE) {
+ dev_dbg(mdrv->dev,
+ "%s %d config_change %d type %d mvdev %p\n",
+ __func__, __LINE__,
+ ioread8(&dc->config_change), ioread8(&d->type), mvdev);
+
+ status = ioread8(&d->status);
+ INIT_COMPLETION(mvdev->reset_done);
+ unregister_virtio_device(&mvdev->vdev);
+ mic_free_card_irq(mvdev->virtio_cookie, mvdev);
+ if (status & VIRTIO_CONFIG_S_DRIVER_OK)
+ wait_for_completion(&mvdev->reset_done);
+ kfree(mvdev);
+ iowrite8(1, &dc->guest_ack);
+ dev_dbg(mdrv->dev, "%s %d guest_ack %d\n",
+ __func__, __LINE__, ioread8(&dc->guest_ack));
+ ret = 0;
+ }
+
+ return ret;
+}
+
+#define REMOVE_DEVICES true
+
+static void mic_scan_devices(struct mic_driver *mdrv, bool remove)
+{
+ s8 type;
+ unsigned int i;
+ struct mic_device_desc __iomem *d;
+ struct mic_device_ctrl __iomem *dc;
+ struct device *dev;
+ int ret;
+
+ for (i = mic_aligned_size(struct mic_bootparam);
+ i < MIC_DP_SIZE; i += mic_total_desc_size(d)) {
+ d = mdrv->dp + i;
+ dc = (void __iomem *)d + mic_aligned_desc_size(d);
+ /*
+ * This read barrier is paired with the corresponding write
+ * barrier on the host which is inserted before adding or
+ * removing a virtio device descriptor, by updating the type.
+ */
+ rmb();
+ type = ioread8(&d->type);
+
+ /* end of list */
+ if (type == 0)
+ break;
+
+ if (type == -1)
+ continue;
+
+ /* device already exists */
+ dev = device_find_child(mdrv->dev, d, mic_match_desc);
+ if (dev) {
+ if (remove)
+ iowrite8(MIC_VIRTIO_PARAM_DEV_REMOVE,
+ &dc->config_change);
+ put_device(dev);
+ mic_handle_config_change(d, i, mdrv);
+ ret = mic_remove_device(d, i, mdrv);
+ if (!ret && !remove)
+ iowrite8(-1, &d->type);
+ if (remove) {
+ iowrite8(0, &dc->config_change);
+ iowrite8(0, &dc->guest_ack);
+ }
+ continue;
+ }
+
+ /* new device */
+ dev_dbg(mdrv->dev, "%s %d Adding new virtio device %p\n",
+ __func__, __LINE__, d);
+ if (!remove)
+ mic_add_device(d, i, mdrv);
+ }
+}
+
+/*
+ * mic_hotplug_device tries to find changes in the device page.
+ */
+static void mic_hotplug_devices(struct work_struct *work)
+{
+ struct mic_driver *mdrv = container_of(work,
+ struct mic_driver, hotplug_work);
+
+ mic_scan_devices(mdrv, !REMOVE_DEVICES);
+}
+
+/*
+ * Interrupt handler for hot plug/config changes etc.
+ */
+static irqreturn_t
+mic_extint_handler(int irq, void *data)
+{
+ struct mic_driver *mdrv = (struct mic_driver *)data;
+
+ dev_dbg(mdrv->dev, "%s %d hotplug work\n",
+ __func__, __LINE__);
+ mic_ack_interrupt(&mdrv->mdev);
+ schedule_work(&mdrv->hotplug_work);
+ return IRQ_HANDLED;
+}
+
+/*
+ * Init function for virtio
+ */
+int mic_devices_init(struct mic_driver *mdrv)
+{
+ int rc;
+ struct mic_bootparam __iomem *bootparam;
+ int config_db;
+
+ INIT_WORK(&mdrv->hotplug_work, mic_hotplug_devices);
+ mic_scan_devices(mdrv, !REMOVE_DEVICES);
+
+ config_db = mic_next_card_db();
+ virtio_config_cookie = mic_request_card_irq(mic_extint_handler,
+ "virtio_config_intr", mdrv, config_db);
+ if (IS_ERR(virtio_config_cookie)) {
+ rc = PTR_ERR(virtio_config_cookie);
+ goto exit;
+ }
+
+ bootparam = mdrv->dp;
+ iowrite8(config_db, &bootparam->h2c_config_db);
+ return 0;
+exit:
+ return rc;
+}
+
+/*
+ * Uninit function for virtio
+ */
+void mic_devices_uninit(struct mic_driver *mdrv)
+{
+ struct mic_bootparam __iomem *bootparam = mdrv->dp;
+ iowrite8(-1, &bootparam->h2c_config_db);
+ mic_free_card_irq(virtio_config_cookie, mdrv);
+ flush_work(&mdrv->hotplug_work);
+ mic_scan_devices(mdrv, REMOVE_DEVICES);
+}
projects / linux-beck.git / commitdiff