vfio/platform: initial interrupts support code

This patch is a skeleton for the VFIO_DEVICE_SET_IRQS IOCTL, around which
most IRQ functionality is implemented in VFIO.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Tested-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

3 files changed, 115 insertions, 3 deletions

diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index 908d5101e053..abcff7a1aa66 100644
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -205,10 +205,54 @@ static long vfio_platform_ioctl(void *device_data,
 
                 return copy_to_user((void __user *)arg, &info, minsz);
 
-        } else if (cmd == VFIO_DEVICE_SET_IRQS)
-                return -EINVAL;
+        } else if (cmd == VFIO_DEVICE_SET_IRQS) {
+                struct vfio_irq_set hdr;
+                u8 *data = NULL;
+                int ret = 0;
+
+                minsz = offsetofend(struct vfio_irq_set, count);
+
+                if (copy_from_user(&hdr, (void __user *)arg, minsz))
+                        return -EFAULT;
+
+                if (hdr.argsz < minsz)
+                        return -EINVAL;
+
+                if (hdr.index >= vdev->num_irqs)
+                        return -EINVAL;
+
+                if (hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
+                                  VFIO_IRQ_SET_ACTION_TYPE_MASK))
+                        return -EINVAL;
 
-        else if (cmd == VFIO_DEVICE_RESET)
+                if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
+                        size_t size;
+
+                        if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
+                                size = sizeof(uint8_t);
+                        else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD)
+                                size = sizeof(int32_t);
+                        else
+                                return -EINVAL;
+
+                        if (hdr.argsz - minsz < size)
+                                return -EINVAL;
+
+                        data = memdup_user((void __user *)(arg + minsz), size);
+                        if (IS_ERR(data))
+                                return PTR_ERR(data);
+                }
+
+                mutex_lock(&vdev->igate);
+
+                ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
+                                                   hdr.start, hdr.count, data);
+                mutex_unlock(&vdev->igate);
+                kfree(data);
+
+                return ret;
+
+        } else if (cmd == VFIO_DEVICE_RESET)
                 return -EINVAL;
 
         return -ENOTTY;
@@ -458,6 +502,8 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
                 return ret;
         }
 
+        mutex_init(&vdev->igate);
+
         return 0;
 }
 EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
index c6c3ec1b9f82..df5c91936a68 100644
--- a/drivers/vfio/platform/vfio_platform_irq.c
+++ b/drivers/vfio/platform/vfio_platform_irq.c
@@ -23,6 +23,56 @@
 
 #include "vfio_platform_private.h"
 
+static int vfio_platform_set_irq_mask(struct vfio_platform_device *vdev,
+                                      unsigned index, unsigned start,
+                                      unsigned count, uint32_t flags,
+                                      void *data)
+{
+        return -EINVAL;
+}
+
+static int vfio_platform_set_irq_unmask(struct vfio_platform_device *vdev,
+                                        unsigned index, unsigned start,
+                                        unsigned count, uint32_t flags,
+                                        void *data)
+{
+        return -EINVAL;
+}
+
+static int vfio_platform_set_irq_trigger(struct vfio_platform_device *vdev,
+                                         unsigned index, unsigned start,
+                                         unsigned count, uint32_t flags,
+                                         void *data)
+{
+        return -EINVAL;
+}
+
+int vfio_platform_set_irqs_ioctl(struct vfio_platform_device *vdev,
+                                 uint32_t flags, unsigned index, unsigned start,
+                                 unsigned count, void *data)
+{
+        int (*func)(struct vfio_platform_device *vdev, unsigned index,
+                    unsigned start, unsigned count, uint32_t flags,
+                    void *data) = NULL;
+
+        switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
+        case VFIO_IRQ_SET_ACTION_MASK:
+                func = vfio_platform_set_irq_mask;
+                break;
+        case VFIO_IRQ_SET_ACTION_UNMASK:
+                func = vfio_platform_set_irq_unmask;
+                break;
+        case VFIO_IRQ_SET_ACTION_TRIGGER:
+                func = vfio_platform_set_irq_trigger;
+                break;
+        }
+
+        if (!func)
+                return -ENOTTY;
+
+        return func(vdev, index, start, count, flags, data);
+}
+
 int vfio_platform_irq_init(struct vfio_platform_device *vdev)
 {
         int cnt = 0, i;
@@ -35,13 +85,22 @@ int vfio_platform_irq_init(struct vfio_platform_device *vdev)
                 return -ENOMEM;
 
         for (i = 0; i < cnt; i++) {
+                int hwirq = vdev->get_irq(vdev, i);
+
+                if (hwirq < 0)
+                        goto err;
+
                 vdev->irqs[i].flags = 0;
                 vdev->irqs[i].count = 1;
+                vdev->irqs[i].hwirq = hwirq;
         }
 
         vdev->num_irqs = cnt;
 
         return 0;
+err:
+        kfree(vdev->irqs);
+        return -EINVAL;
 }
 
 void vfio_platform_irq_cleanup(struct vfio_platform_device *vdev)
diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
index a2e286ed1407..b119a6c5ac23 100644
--- a/drivers/vfio/platform/vfio_platform_private.h
+++ b/drivers/vfio/platform/vfio_platform_private.h
@@ -30,6 +30,7 @@
 struct vfio_platform_irq {
         u32                     flags;
         u32                     count;
+        int                     hwirq;
 };
 
 struct vfio_platform_region {
@@ -48,6 +49,7 @@ struct vfio_platform_device {
         struct vfio_platform_irq        *irqs;
         u32                             num_irqs;
         int                             refcnt;
+        struct mutex                    igate;
 
         /*
          * These fields should be filled by the bus specific binder
@@ -69,4 +71,9 @@ extern struct vfio_platform_device *vfio_platform_remove_common
 extern int vfio_platform_irq_init(struct vfio_platform_device *vdev);
 extern void vfio_platform_irq_cleanup(struct vfio_platform_device *vdev);
 
+extern int vfio_platform_set_irqs_ioctl(struct vfio_platform_device *vdev,
+                                        uint32_t flags, unsigned index,
+                                        unsigned start, unsigned count,
+                                        void *data);
+
 #endif /* VFIO_PLATFORM_PRIVATE_H */