From: okaya@codeaurora.org (Sinan Kaya)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH V9 6/9] vfio: platform: call _RST method when using ACPI
Date: Wed, 13 Jul 2016 22:06:32 -0400 [thread overview]
Message-ID: <1468461995-32676-7-git-send-email-okaya@codeaurora.org> (raw)
In-Reply-To: <1468461995-32676-1-git-send-email-okaya@codeaurora.org>
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>
---
drivers/vfio/platform/vfio_platform_common.c | 52 +++++++++++++++++++++++++++-
1 file changed, 51 insertions(+), 1 deletion(-)
diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index 03483c2..2d9c905 100644
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -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);
@@ -77,13 +79,55 @@ static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev,
#endif
}
+static inline
+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
+}
+
+static inline
+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) {
@@ -95,6 +139,9 @@ 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);
}
@@ -170,7 +217,10 @@ 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);
}
--
1.8.2.1
next prev parent reply other threads:[~2016-07-14 2:06 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-14 2:06 [PATCH V9 0/9] vfio, platform: add ACPI support Sinan Kaya
2016-07-14 2:06 ` [PATCH V9 1/9] vfio: platform: rename reset function Sinan Kaya
2016-07-14 2:06 ` [PATCH V9 2/9] vfio: platform: move reset call to a common function Sinan Kaya
2016-07-14 2:06 ` [PATCH V9 3/9] vfio: platform: determine reset capability Sinan Kaya
2016-07-14 2:06 ` [PATCH V9 4/9] vfio: platform: add support for ACPI probe Sinan Kaya
2016-07-14 21:41 ` Alex Williamson
2016-07-16 1:27 ` Sinan Kaya
2016-07-18 17:32 ` Alex Williamson
2016-07-18 21:23 ` Sinan Kaya
2016-07-14 2:06 ` [PATCH V9 5/9] vfio: platform: add extra debug info argument to call reset Sinan Kaya
2016-07-14 2:06 ` Sinan Kaya [this message]
2016-07-14 22:04 ` [PATCH V9 6/9] vfio: platform: call _RST method when using ACPI Alex Williamson
2016-07-16 1:09 ` Sinan Kaya
2016-07-14 2:06 ` [PATCH V9 7/9] vfio, platform: make reset driver a requirement by default Sinan Kaya
2016-07-14 22:24 ` Alex Williamson
2016-07-16 1:07 ` Sinan Kaya
2016-07-14 2:06 ` [PATCH V9 8/9] vfio: platform: check reset call return code during open Sinan Kaya
2016-07-14 2:06 ` [PATCH V9 9/9] vfio: platform: check reset call return code during release Sinan Kaya
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