drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c

   1 // SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
   2 /*
   3  * Copyright 2013-2016 Freescale Semiconductor Inc.
   4  * Copyright 2019 NXP
   5  */
   6
   7 #include <linux/vfio.h>
   8 #include <linux/slab.h>
   9 #include <linux/types.h>
  10 #include <linux/eventfd.h>
  11 #include <linux/msi.h>
  12
  13 #include "linux/fsl/mc.h"
  14 #include "vfio_fsl_mc_private.h"
  15
  16 static int vfio_fsl_mc_irqs_allocate(struct vfio_fsl_mc_device *vdev)
  17 {
  18         struct fsl_mc_device *mc_dev = vdev->mc_dev;
  19         struct vfio_fsl_mc_irq *mc_irq;
  20         int irq_count;
  21         int ret, i;
  22
  23         /* Device does not support any interrupt */
  24         if (mc_dev->obj_desc.irq_count == 0)
  25                 return 0;
  26
  27         /* interrupts were already allocated for this device */
  28         if (vdev->mc_irqs)
  29                 return 0;
  30
  31         irq_count = mc_dev->obj_desc.irq_count;
  32
  33         mc_irq = kcalloc(irq_count, sizeof(*mc_irq), GFP_KERNEL);
  34         if (!mc_irq)
  35                 return -ENOMEM;
  36
  37         /* Allocate IRQs */
  38         ret = fsl_mc_allocate_irqs(mc_dev);
  39         if (ret) {
  40                 kfree(mc_irq);
  41                 return ret;
  42         }
  43
  44         for (i = 0; i < irq_count; i++) {
  45                 mc_irq[i].count = 1;
  46                 mc_irq[i].flags = VFIO_IRQ_INFO_EVENTFD;
  47         }
  48
  49         vdev->mc_irqs = mc_irq;
  50
  51         return 0;
  52 }
  53
  54 static irqreturn_t vfio_fsl_mc_irq_handler(int irq_num, void *arg)
  55 {
  56         struct vfio_fsl_mc_irq *mc_irq = (struct vfio_fsl_mc_irq *)arg;
  57
  58         eventfd_signal(mc_irq->trigger, 1);
  59         return IRQ_HANDLED;
  60 }
  61
  62 static int vfio_set_trigger(struct vfio_fsl_mc_device *vdev,
  63                                                    int index, int fd)
  64 {
  65         struct vfio_fsl_mc_irq *irq = &vdev->mc_irqs[index];
  66         struct eventfd_ctx *trigger;
  67         int hwirq;
  68         int ret;
  69
  70         hwirq = vdev->mc_dev->irqs[index]->msi_desc->irq;
  71         if (irq->trigger) {
  72                 free_irq(hwirq, irq);
  73                 kfree(irq->name);
  74                 eventfd_ctx_put(irq->trigger);
  75                 irq->trigger = NULL;
  76         }
  77
  78         if (fd < 0) /* Disable only */
  79                 return 0;
  80
  81         irq->name = kasprintf(GFP_KERNEL, "vfio-irq[%d](%s)",
  82                             hwirq, dev_name(&vdev->mc_dev->dev));
  83         if (!irq->name)
  84                 return -ENOMEM;
  85
  86         trigger = eventfd_ctx_fdget(fd);
  87         if (IS_ERR(trigger)) {
  88                 kfree(irq->name);
  89                 return PTR_ERR(trigger);
  90         }
  91
  92         irq->trigger = trigger;
  93
  94         ret = request_irq(hwirq, vfio_fsl_mc_irq_handler, 0,
  95                   irq->name, irq);
  96         if (ret) {
  97                 kfree(irq->name);
  98                 eventfd_ctx_put(trigger);
  99                 irq->trigger = NULL;
 100                 return ret;
 101         }
 102
 103         return 0;
 104 }
 105
 106 static int vfio_fsl_mc_set_irq_trigger(struct vfio_fsl_mc_device *vdev,
 107                                        unsigned int index, unsigned int start,
 108                                        unsigned int count, u32 flags,
 109                                        void *data)
 110 {
 111         struct fsl_mc_device *mc_dev = vdev->mc_dev;
 112         int ret, hwirq;
 113         struct vfio_fsl_mc_irq *irq;
 114         struct device *cont_dev = fsl_mc_cont_dev(&mc_dev->dev);
 115         struct fsl_mc_device *mc_cont = to_fsl_mc_device(cont_dev);
 116
 117         if (!count && (flags & VFIO_IRQ_SET_DATA_NONE))
 118                 return vfio_set_trigger(vdev, index, -1);
 119
 120         if (start != 0 || count != 1)
 121                 return -EINVAL;
 122
 123         mutex_lock(&vdev->reflck->lock);
 124         ret = fsl_mc_populate_irq_pool(mc_cont,
 125                         FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS);
 126         if (ret)
 127                 goto unlock;
 128
 129         ret = vfio_fsl_mc_irqs_allocate(vdev);
 130         if (ret)
 131                 goto unlock;
 132         mutex_unlock(&vdev->reflck->lock);
 133
 134         if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
 135                 s32 fd = *(s32 *)data;
 136
 137                 return vfio_set_trigger(vdev, index, fd);
 138         }
 139
 140         hwirq = vdev->mc_dev->irqs[index]->msi_desc->irq;
 141
 142         irq = &vdev->mc_irqs[index];
 143
 144         if (flags & VFIO_IRQ_SET_DATA_NONE) {
 145                 vfio_fsl_mc_irq_handler(hwirq, irq);
 146
 147         } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
 148                 u8 trigger = *(u8 *)data;
 149
 150                 if (trigger)
 151                         vfio_fsl_mc_irq_handler(hwirq, irq);
 152         }
 153
 154         return 0;
 155
 156 unlock:
 157         mutex_unlock(&vdev->reflck->lock);
 158         return ret;
 159
 160 }
 161
 162 int vfio_fsl_mc_set_irqs_ioctl(struct vfio_fsl_mc_device *vdev,
 163                                u32 flags, unsigned int index,
 164                                unsigned int start, unsigned int count,
 165                                void *data)
 166 {
 167         if (flags & VFIO_IRQ_SET_ACTION_TRIGGER)
 168                 return  vfio_fsl_mc_set_irq_trigger(vdev, index, start,
 169                           count, flags, data);
 170         else
 171                 return -EINVAL;
 172 }
 173
 174 /* Free All IRQs for the given MC object */
 175 void vfio_fsl_mc_irqs_cleanup(struct vfio_fsl_mc_device *vdev)
 176 {
 177         struct fsl_mc_device *mc_dev = vdev->mc_dev;
 178         int irq_count = mc_dev->obj_desc.irq_count;
 179         int i;
 180
 181         /*
 182          * Device does not support any interrupt or the interrupts
 183          * were not configured
 184          */
 185         if (!vdev->mc_irqs)
 186                 return;
 187
 188         for (i = 0; i < irq_count; i++)
 189                 vfio_set_trigger(vdev, i, -1);
 190
 191         fsl_mc_free_irqs(mc_dev);
 192         kfree(vdev->mc_irqs);
 193         vdev->mc_irqs = NULL;
 194 }