target/linux/layerscape/patches-5.4/821-vfio-0008-vfio-fsl-mc-trigger-an-interrupt-via-eventfd.patch

   1 From 8f0239c9385028a0c15306966c66a56315b11dbc Mon Sep 17 00:00:00 2001
   2 From: Diana Craciun <diana.craciun@nxp.com>
   3 Date: Tue, 1 Oct 2019 16:44:04 +0300
   4 Subject: [PATCH] vfio/fsl-mc: trigger an interrupt via eventfd
   5
   6 This patch allows to set an eventfd for fsl-mc device interrupt
   7 and also to trigger the interrupt eventfd from userspace for testing.
   8
   9 All fsl-mc device interrupts are MSI type. This does not yet handle
  10 correctly DPRC container interrupt where re-scanning on container is
  11 required.
  12
  13 Signed-off-by: Bharat Bhushan <Bharat.Bhushan@nxp.com>
  14 Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
  15 ---
  16  drivers/vfio/fsl-mc/vfio_fsl_mc.c         |  20 +++-
  17  drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c    | 165 +++++++++++++++++++++++++++++-
  18  drivers/vfio/fsl-mc/vfio_fsl_mc_private.h |  10 ++
  19  3 files changed, 193 insertions(+), 2 deletions(-)
  20
  21 --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
  22 +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
  23 @@ -144,12 +144,30 @@ err_reg_init:
  24  static void vfio_fsl_mc_release(void *device_data)
  25  {
  26         struct vfio_fsl_mc_device *vdev = device_data;
  27 +       int ret;
  28
  29         mutex_lock(&vdev->reflck->lock);
  30
  31 -       if (!(--vdev->refcnt))
  32 +       if (!(--vdev->refcnt)) {
  33 +               struct fsl_mc_device *mc_dev = vdev->mc_dev;
  34 +               struct device *cont_dev = fsl_mc_cont_dev(&mc_dev->dev);
  35 +               struct fsl_mc_device *mc_cont = to_fsl_mc_device(cont_dev);
  36 +               struct fsl_mc_bus *mc_bus;
  37 +
  38 +               mc_bus = to_fsl_mc_bus(mc_cont);
  39 +
  40                 vfio_fsl_mc_regions_cleanup(vdev);
  41
  42 +               /* reset the device before cleaning up the interrupts */
  43 +               ret = dprc_reset_container(mc_dev->mc_io, 0,
  44 +                     mc_dev->mc_handle,
  45 +                         mc_dev->obj_desc.id);
  46 +
  47 +               vfio_fsl_mc_irqs_cleanup(vdev);
  48 +
  49 +               fsl_mc_cleanup_irq_pool(mc_bus);
  50 +       }
  51 +
  52         mutex_unlock(&vdev->reflck->lock);
  53
  54         module_put(THIS_MODULE);
  55 --- a/drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c
  56 +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c
  57 @@ -29,12 +29,154 @@ static int vfio_fsl_mc_irq_unmask(struct
  58         return -EINVAL;
  59  }
  60
  61 +int vfio_fsl_mc_irqs_allocate(struct vfio_fsl_mc_device *vdev)
  62 +{
  63 +       struct fsl_mc_device *mc_dev = vdev->mc_dev;
  64 +       struct vfio_fsl_mc_irq *mc_irq;
  65 +       int irq_count;
  66 +       int ret, i;
  67 +
  68 +    /* Device does not support any interrupt */
  69 +       if (mc_dev->obj_desc.irq_count == 0)
  70 +               return 0;
  71 +
  72 +       /* interrupts were already allocated for this device */
  73 +       if (vdev->mc_irqs)
  74 +               return 0;
  75 +
  76 +       irq_count = mc_dev->obj_desc.irq_count;
  77 +
  78 +       mc_irq = kcalloc(irq_count, sizeof(*mc_irq), GFP_KERNEL);
  79 +       if (mc_irq == NULL)
  80 +               return -ENOMEM;
  81 +
  82 +       /* Allocate IRQs */
  83 +       ret = fsl_mc_allocate_irqs(mc_dev);
  84 +       if (ret) {
  85 +               kfree(mc_irq);
  86 +               return ret;
  87 +       }
  88 +
  89 +       for (i = 0; i < irq_count; i++) {
  90 +               mc_irq[i].count = 1;
  91 +               mc_irq[i].flags = VFIO_IRQ_INFO_EVENTFD;
  92 +       }
  93 +
  94 +       vdev->mc_irqs = mc_irq;
  95 +
  96 +       return 0;
  97 +}
  98 +static irqreturn_t vfio_fsl_mc_irq_handler(int irq_num, void *arg)
  99 +{
 100 +       struct vfio_fsl_mc_irq *mc_irq = (struct vfio_fsl_mc_irq *)arg;
 101 +
 102 +       eventfd_signal(mc_irq->trigger, 1);
 103 +       return IRQ_HANDLED;
 104 +}
 105 +
 106 +static int vfio_set_trigger(struct vfio_fsl_mc_device *vdev,
 107 +                                                  int index, int fd)
 108 +{
 109 +       struct vfio_fsl_mc_irq *irq = &vdev->mc_irqs[index];
 110 +       struct eventfd_ctx *trigger;
 111 +       int hwirq;
 112 +       int ret;
 113 +
 114 +       hwirq = vdev->mc_dev->irqs[index]->msi_desc->irq;
 115 +       if (irq->trigger) {
 116 +               free_irq(hwirq, irq);
 117 +               kfree(irq->name);
 118 +               eventfd_ctx_put(irq->trigger);
 119 +               irq->trigger = NULL;
 120 +       }
 121 +
 122 +       if (fd < 0) /* Disable only */
 123 +               return 0;
 124 +
 125 +       irq->name = kasprintf(GFP_KERNEL, "vfio-irq[%d](%s)",
 126 +                           hwirq, dev_name(&vdev->mc_dev->dev));
 127 +       if (!irq->name)
 128 +               return -ENOMEM;
 129 +
 130 +       trigger = eventfd_ctx_fdget(fd);
 131 +       if (IS_ERR(trigger)) {
 132 +               kfree(irq->name);
 133 +               return PTR_ERR(trigger);
 134 +       }
 135 +
 136 +       irq->trigger = trigger;
 137 +
 138 +       ret = request_irq(hwirq, vfio_fsl_mc_irq_handler, 0,
 139 +                 irq->name, irq);
 140 +       if (ret) {
 141 +               kfree(irq->name);
 142 +               eventfd_ctx_put(trigger);
 143 +               irq->trigger = NULL;
 144 +               return ret;
 145 +       }
 146 +
 147 +       return 0;
 148 +}
 149 +
 150  static int vfio_fsl_mc_set_irq_trigger(struct vfio_fsl_mc_device *vdev,
 151                                        unsigned int index, unsigned int start,
 152                                        unsigned int count, uint32_t flags,
 153                                        void *data)
 154  {
 155 -       return -EINVAL;
 156 +       struct fsl_mc_device *mc_dev = vdev->mc_dev;
 157 +       struct fsl_mc_bus *mc_bus;
 158 +       int ret, hwirq;
 159 +       struct vfio_fsl_mc_irq *irq;
 160 +       struct device *cont_dev = fsl_mc_cont_dev(&mc_dev->dev);
 161 +       struct fsl_mc_device *mc_cont = to_fsl_mc_device(cont_dev);
 162 +
 163 +       if (start != 0 || count != 1)
 164 +               return -EINVAL;
 165 +
 166 +       mc_bus = to_fsl_mc_bus(mc_cont);
 167 +
 168 +       mutex_lock(&vdev->reflck->lock);
 169 +       if (!mc_bus->irq_resources) {
 170 +
 171 +               ret = fsl_mc_populate_irq_pool(mc_bus,
 172 +                       FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS);
 173 +               if (ret)
 174 +                       goto unlock;
 175 +       }
 176 +
 177 +       ret = vfio_fsl_mc_irqs_allocate(vdev);
 178 +       if (ret)
 179 +               goto unlock;
 180 +       mutex_unlock(&vdev->reflck->lock);
 181 +
 182 +       if (!count && (flags & VFIO_IRQ_SET_DATA_NONE))
 183 +               return vfio_set_trigger(vdev, index, -1);
 184 +
 185 +       if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
 186 +               int32_t fd = *(int32_t *)data;
 187 +
 188 +               return vfio_set_trigger(vdev, index, fd);
 189 +       }
 190 +
 191 +       hwirq = vdev->mc_dev->irqs[index]->msi_desc->irq;
 192 +
 193 +       irq = &vdev->mc_irqs[index];
 194 +
 195 +       if (flags & VFIO_IRQ_SET_DATA_NONE) {
 196 +               vfio_fsl_mc_irq_handler(hwirq, irq);
 197 +
 198 +       } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
 199 +               uint8_t trigger = *(uint8_t *)data;
 200 +
 201 +               if (trigger)
 202 +                       vfio_fsl_mc_irq_handler(hwirq, irq);
 203 +       }
 204 +
 205 +       return 0;
 206 +
 207 +unlock:
 208 +       mutex_unlock(&vdev->reflck->lock);
 209 +       return ret;
 210  }
 211  int vfio_fsl_mc_set_irqs_ioctl(struct vfio_fsl_mc_device *vdev,
 212                                uint32_t flags, unsigned int index,
 213 @@ -60,3 +202,24 @@ int vfio_fsl_mc_set_irqs_ioctl(struct vf
 214
 215         return ret;
 216  }
 217 +
 218 +/* Free All IRQs for the given MC object */
 219 +void vfio_fsl_mc_irqs_cleanup(struct vfio_fsl_mc_device *vdev)
 220 +{
 221 +       struct fsl_mc_device *mc_dev = vdev->mc_dev;
 222 +       int irq_count = mc_dev->obj_desc.irq_count;
 223 +       int i;
 224 +
 225 +       /* Device does not support any interrupt or the interrupts
 226 +        * were not configured
 227 +        */
 228 +       if (mc_dev->obj_desc.irq_count == 0 || !vdev->mc_irqs)
 229 +               return;
 230 +
 231 +       for (i = 0; i < irq_count; i++)
 232 +               vfio_set_trigger(vdev, i, -1);
 233 +
 234 +       fsl_mc_free_irqs(mc_dev);
 235 +       kfree(vdev->mc_irqs);
 236 +       vdev->mc_irqs = NULL;
 237 +}
 238 --- a/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
 239 +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
 240 @@ -15,6 +15,13 @@
 241  #define VFIO_FSL_MC_INDEX_TO_OFFSET(index)     \
 242         ((u64)(index) << VFIO_FSL_MC_OFFSET_SHIFT)
 243
 244 +struct vfio_fsl_mc_irq {
 245 +       u32         flags;
 246 +       u32         count;
 247 +       struct eventfd_ctx  *trigger;
 248 +       char            *name;
 249 +};
 250 +
 251  struct vfio_fsl_mc_reflck {
 252         struct kref             kref;
 253         struct mutex            lock;
 254 @@ -33,6 +40,7 @@ struct vfio_fsl_mc_device {
 255         u32                             num_regions;
 256         struct vfio_fsl_mc_region       *regions;
 257         struct vfio_fsl_mc_reflck   *reflck;
 258 +       struct vfio_fsl_mc_irq      *mc_irqs;
 259  };
 260
 261  int vfio_fsl_mc_set_irqs_ioctl(struct vfio_fsl_mc_device *vdev,
 262 @@ -40,4 +48,6 @@ int vfio_fsl_mc_set_irqs_ioctl(struct vf
 263                                unsigned int start, unsigned int count,
 264                                void *data);
 265
 266 +void vfio_fsl_mc_irqs_cleanup(struct vfio_fsl_mc_device *vdev);
 267 +
 268  #endif /* VFIO_PCI_PRIVATE_H */