redonkable/remarkable-linux
redonkable/remarkable-linux
1
0
Fork 0
Code Releases Activity

vfio: platform: call _RST method when using ACPI

Browse source 
The device tree code checks for the presence of a reset driver and calls
the of_reset function pointer by looking up the reset driver as a module.

ACPI defines _RST method to perform device level reset. After the _RST
method is executed, the OS can resume using the device. _RST method is
expected to stop DMA transfers and IRQs.

This patch introduces two functions as vfio_platform_acpi_has_reset and
vfio_platform_acpi_call_reset. The has reset method is used to declare
reset capability via the ioctl flag VFIO_DEVICE_FLAGS_RESET. The call
reset function is used to execute the _RST ACPI method.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Sinan Kaya 2016-07-19 09:01:46 -04:00 committed by Alex Williamson
parent 5afec27474
commit d30daa33ec
1 changed files with 49 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

50
drivers/vfio/platform/vfio_platform_common.c
View file

@ -28,6 +28,8 @@
#define DRIVER_AUTHOR "Antonios Motakis <a.motakis@virtualopensystems.com>"
#define DRIVER_DESC "VFIO platform base module"
#define VFIO_PLATFORM_IS_ACPI(vdev) ((vdev)->acpihid != NULL)
static LIST_HEAD(reset_list);
static DEFINE_MUTEX(driver_lock);
@ -71,13 +73,53 @@ static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev,
return WARN_ON(!vdev->acpihid) ? -EINVAL : 0;
}
int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev,
const char **extra_dbg)
{
#ifdef CONFIG_ACPI
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
struct device *dev = vdev->device;
acpi_handle handle = ACPI_HANDLE(dev);
acpi_status acpi_ret;
acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, &buffer);
if (ACPI_FAILURE(acpi_ret)) {
if (extra_dbg)
*extra_dbg = acpi_format_exception(acpi_ret);
return -EINVAL;
}
return 0;
#else
return -ENOENT;
#endif
}
bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev)
{
#ifdef CONFIG_ACPI
struct device *dev = vdev->device;
acpi_handle handle = ACPI_HANDLE(dev);
return acpi_has_method(handle, "_RST");
#else
return false;
#endif
}
static bool vfio_platform_has_reset(struct vfio_platform_device *vdev)
{
if (VFIO_PLATFORM_IS_ACPI(vdev))
return vfio_platform_acpi_has_reset(vdev);
return vdev->of_reset ? true : false;
}
static void vfio_platform_get_reset(struct vfio_platform_device *vdev)
{
if (VFIO_PLATFORM_IS_ACPI(vdev))
return;
vdev->of_reset = vfio_platform_lookup_reset(vdev->compat,
&vdev->reset_module);
if (!vdev->of_reset) {
@ -89,6 +131,9 @@ static void vfio_platform_get_reset(struct vfio_platform_device *vdev)
static void vfio_platform_put_reset(struct vfio_platform_device *vdev)
{
if (VFIO_PLATFORM_IS_ACPI(vdev))
return;
if (vdev->of_reset)
module_put(vdev->reset_module);
}
@ -164,7 +209,10 @@ static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
static int vfio_platform_call_reset(struct vfio_platform_device *vdev,
const char **extra_dbg)
{
if (vdev->of_reset) {
if (VFIO_PLATFORM_IS_ACPI(vdev)) {
dev_info(vdev->device, "reset\n");
return vfio_platform_acpi_call_reset(vdev, extra_dbg);
} else if (vdev->of_reset) {
dev_info(vdev->device, "reset\n");
return vdev->of_reset(vdev);
}