[PATCH v14 07/20] vfio/platform: return info for device memory mapped IO regions

Baptiste Reynal
2015-03-02T17:01:37Z

This patch enables the IOCTLs VFIO_DEVICE_GET_REGION_INFO ioctl call,
which allows the user to learn about the available MMIO resources of
a device.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
---
drivers/vfio/platform/vfio_platform_common.c | 106 +++++++++++++++++++++++++-
drivers/vfio/platform/vfio_platform_private.h | 22 ++++++
2 files changed, 124 insertions(+), 4 deletions(-)

diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index c2f853a..47f6309 100644
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -23,17 +23,97 @@

#include "vfio_platform_private.h"

+static DEFINE_MUTEX(driver_lock);
+
+static int vfio_platform_regions_init(struct vfio_platform_device *vdev)
+{
+ int cnt = 0, i;
+
+ while (vdev->get_resource(vdev, cnt))
+ cnt++;
+
+ vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region),
+ GFP_KERNEL);
+ if (!vdev->regions)
+ return -ENOMEM;
+
+ for (i = 0; i < cnt; i++) {
+ struct resource *res =
+ vdev->get_resource(vdev, i);
+
+ if (!res)
+ goto err;
+
+ vdev->regions[i].addr = res->start;
+ vdev->regions[i].size = resource_size(res);
+ vdev->regions[i].flags = 0;
+
+ switch (resource_type(res)) {
+ case IORESOURCE_MEM:
+ vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO;
+ break;
+ case IORESOURCE_IO:
+ vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO;
+ break;
+ default:
+ goto err;
+ }
+ }
+
+ vdev->num_regions = cnt;
+
+ return 0;
+err:
+ kfree(vdev->regions);
+ return -EINVAL;
+}
+
+static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
+{
+ vdev->num_regions = 0;
+ kfree(vdev->regions);
+}
+
static void vfio_platform_release(void *device_data)
{
+ struct vfio_platform_device *vdev = device_data;
+
+ mutex_lock(&driver_lock);
+
+ if (!(--vdev->refcnt)) {
+ vfio_platform_regions_cleanup(vdev);
+ }
+
+ mutex_unlock(&driver_lock);
+
module_put(THIS_MODULE);
}

static int vfio_platform_open(void *device_data)
{
+ struct vfio_platform_device *vdev = device_data;
+ int ret;
+
if (!try_module_get(THIS_MODULE))
return -ENODEV;

+ mutex_lock(&driver_lock);
+
+ if (!vdev->refcnt) {
+ ret = vfio_platform_regions_init(vdev);
+ if (ret)
+ goto err_reg;
+ }
+
+ vdev->refcnt++;
+
+ mutex_unlock(&driver_lock);
return 0;
+
+err_reg:
+ mutex_unlock(&driver_lock);
+ module_put(THIS_MODULE);
+ return ret;
}

static long vfio_platform_ioctl(void *device_data,
@@ -54,15 +134,33 @@ static long vfio_platform_ioctl(void *device_data,
return -EINVAL;

info.flags = vdev->flags;
- info.num_regions = 0;
+ info.num_regions = vdev->num_regions;
info.num_irqs = 0;

return copy_to_user((void __user *)arg, &info, minsz);

- } else if (cmd == VFIO_DEVICE_GET_REGION_INFO)
- return -EINVAL;
+ } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
+ struct vfio_region_info info;
+
+ minsz = offsetofend(struct vfio_region_info, offset);
+
+ if (copy_from_user(&info, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (info.argsz < minsz)
+ return -EINVAL;
+
+ if (info.index >= vdev->num_regions)
+ return -EINVAL;
+
+ /* map offset to the physical address */
+ info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
+ info.size = vdev->regions[info.index].size;
+ info.flags = vdev->regions[info.index].flags;
+
+ return copy_to_user((void __user *)arg, &info, minsz);

- else if (cmd == VFIO_DEVICE_GET_IRQ_INFO)
+ } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO)
return -EINVAL;

else if (cmd == VFIO_DEVICE_SET_IRQS)
diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
index c046988..3551f6d 100644
--- a/drivers/vfio/platform/vfio_platform_private.h
+++ b/drivers/vfio/platform/vfio_platform_private.h
@@ -18,7 +18,29 @@
#include <linux/types.h>
#include <linux/interrupt.h>

+#define VFIO_PLATFORM_OFFSET_SHIFT 40
+#define VFIO_PLATFORM_OFFSET_MASK (((u64)(1) << VFIO_PLATFORM_OFFSET_SHIFT) - 1)
+
+#define VFIO_PLATFORM_OFFSET_TO_INDEX(off) \
+ (off >> VFIO_PLATFORM_OFFSET_SHIFT)
+
+#define VFIO_PLATFORM_INDEX_TO_OFFSET(index) \
+ ((u64)(index) << VFIO_PLATFORM_OFFSET_SHIFT)
+
+struct vfio_platform_region {
+ u64 addr;
+ resource_size_t size;
+ u32 flags;
+ u32 type;
+#define VFIO_PLATFORM_REGION_TYPE_MMIO 1
+#define VFIO_PLATFORM_REGION_TYPE_PIO 2
+};
+
struct vfio_platform_device {
+ struct vfio_platform_region *regions;
+ u32 num_regions;
+ int refcnt;
+
/*
* These fields should be filled by the bus specific binder
*/
--
2.3.1