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