vfio/platform: return IRQ info

Return information for the interrupts exposed by the device.
This patch extends VFIO_DEVICE_GET_INFO with the number of IRQs
and enables VFIO_DEVICE_GET_IRQ_INFO.

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>

4 files changed, 89 insertions, 5 deletions

diff --git a/drivers/vfio/platform/Makefile b/drivers/vfio/platform/Makefile
index 1957170ae429..81de144c0eaa 100644
--- a/drivers/vfio/platform/Makefile
+++ b/drivers/vfio/platform/Makefile
@@ -1,5 +1,5 @@
 
-vfio-platform-y := vfio_platform.o vfio_platform_common.o
+vfio-platform-y := vfio_platform.o vfio_platform_common.o vfio_platform_irq.o
 
 obj-$(CONFIG_VFIO_PLATFORM) += vfio-platform.o
 
diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index d7fe2c71e8bc..908d5101e053 100644
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -101,6 +101,7 @@ static void vfio_platform_release(void *device_data)
 
         if (!(--vdev->refcnt)) {
                 vfio_platform_regions_cleanup(vdev);
+                vfio_platform_irq_cleanup(vdev);
         }
 
         mutex_unlock(&driver_lock);
@@ -122,6 +123,10 @@ static int vfio_platform_open(void *device_data)
                 ret = vfio_platform_regions_init(vdev);
                 if (ret)
                         goto err_reg;
+
+                ret = vfio_platform_irq_init(vdev);
+                if (ret)
+                        goto err_irq;
         }
 
         vdev->refcnt++;
@@ -129,6 +134,8 @@ static int vfio_platform_open(void *device_data)
         mutex_unlock(&driver_lock);
         return 0;
 
+err_irq:
+        vfio_platform_regions_cleanup(vdev);
 err_reg:
         mutex_unlock(&driver_lock);
         module_put(THIS_MODULE);
@@ -154,7 +161,7 @@ static long vfio_platform_ioctl(void *device_data,
 
                 info.flags = vdev->flags;
                 info.num_regions = vdev->num_regions;
-                info.num_irqs = 0;
+                info.num_irqs = vdev->num_irqs;
 
                 return copy_to_user((void __user *)arg, &info, minsz);
 
@@ -179,10 +186,26 @@ static long vfio_platform_ioctl(void *device_data,
 
                 return copy_to_user((void __user *)arg, &info, minsz);
 
-        } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO)
-                return -EINVAL;
+        } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
+                struct vfio_irq_info info;
+
+                minsz = offsetofend(struct vfio_irq_info, count);
+
+                if (copy_from_user(&info, (void __user *)arg, minsz))
+                        return -EFAULT;
+
+                if (info.argsz < minsz)
+                        return -EINVAL;
+
+                if (info.index >= vdev->num_irqs)
+                        return -EINVAL;
+
+                info.flags = vdev->irqs[info.index].flags;
+                info.count = vdev->irqs[info.index].count;
+
+                return copy_to_user((void __user *)arg, &info, minsz);
 
-        else if (cmd == VFIO_DEVICE_SET_IRQS)
+        } else if (cmd == VFIO_DEVICE_SET_IRQS)
                 return -EINVAL;
 
         else if (cmd == VFIO_DEVICE_RESET)
diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
new file mode 100644
index 000000000000..c6c3ec1b9f82
--- /dev/null
+++ b/drivers/vfio/platform/vfio_platform_irq.c
@@ -0,0 +1,51 @@
+/*
+ * VFIO platform devices interrupt handling
+ *
+ * Copyright (C) 2013 - Virtual Open Systems
+ * Author: Antonios Motakis <a.motakis@virtualopensystems.com>
+ *
+ * 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.
+ */
+
+#include <linux/eventfd.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/vfio.h>
+#include <linux/irq.h>
+
+#include "vfio_platform_private.h"
+
+int vfio_platform_irq_init(struct vfio_platform_device *vdev)
+{
+        int cnt = 0, i;
+
+        while (vdev->get_irq(vdev, cnt) >= 0)
+                cnt++;
+
+        vdev->irqs = kcalloc(cnt, sizeof(struct vfio_platform_irq), GFP_KERNEL);
+        if (!vdev->irqs)
+                return -ENOMEM;
+
+        for (i = 0; i < cnt; i++) {
+                vdev->irqs[i].flags = 0;
+                vdev->irqs[i].count = 1;
+        }
+
+        vdev->num_irqs = cnt;
+
+        return 0;
+}
+
+void vfio_platform_irq_cleanup(struct vfio_platform_device *vdev)
+{
+        vdev->num_irqs = 0;
+        kfree(vdev->irqs);
+}
diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
index 97c78f9791f1..a2e286ed1407 100644
--- a/drivers/vfio/platform/vfio_platform_private.h
+++ b/drivers/vfio/platform/vfio_platform_private.h
@@ -27,6 +27,11 @@
 #define VFIO_PLATFORM_INDEX_TO_OFFSET(index)    \
         ((u64)(index) << VFIO_PLATFORM_OFFSET_SHIFT)
 
+struct vfio_platform_irq {
+        u32                     flags;
+        u32                     count;
+};
+
 struct vfio_platform_region {
         u64                     addr;
         resource_size_t         size;
@@ -40,6 +45,8 @@ struct vfio_platform_region {
 struct vfio_platform_device {
         struct vfio_platform_region     *regions;
         u32                             num_regions;
+        struct vfio_platform_irq        *irqs;
+        u32                             num_irqs;
         int                             refcnt;
 
         /*
@@ -59,4 +66,7 @@ extern int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 extern struct vfio_platform_device *vfio_platform_remove_common
                                      (struct device *dev);
 
+extern int vfio_platform_irq_init(struct vfio_platform_device *vdev);
+extern void vfio_platform_irq_cleanup(struct vfio_platform_device *vdev);
+
 #endif /* VFIO_PLATFORM_PRIVATE_H */