diff options
author | Sinan Kaya <okaya@codeaurora.org> | 2016-07-19 16:01:44 +0300 |
---|---|---|
committer | Alex Williamson <alex.williamson@redhat.com> | 2016-07-19 19:26:41 +0300 |
commit | a12a9368e192d56175e49d69360d861025a0f6f7 (patch) | |
tree | 79fc72bc9350f516664ebc434c2acdd11192c2ca /drivers/vfio | |
parent | dc5542fb115a9576493831160e31d355b58541d7 (diff) | |
download | linux-a12a9368e192d56175e49d69360d861025a0f6f7.tar.xz |
vfio: platform: add support for ACPI probe
The code is using the compatible DT string to associate a reset driver
with the actual device itself. The compatible string does not exist on
ACPI based systems. HID is the unique identifier for a device driver
instead.
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio')
-rw-r--r-- | drivers/vfio/platform/vfio_platform_common.c | 64 | ||||
-rw-r--r-- | drivers/vfio/platform/vfio_platform_private.h | 1 |
2 files changed, 60 insertions, 5 deletions
diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c index 307d61d2aea2..716f421d1b01 100644 --- a/drivers/vfio/platform/vfio_platform_common.c +++ b/drivers/vfio/platform/vfio_platform_common.c @@ -13,6 +13,7 @@ */ #include <linux/device.h> +#include <linux/acpi.h> #include <linux/iommu.h> #include <linux/module.h> #include <linux/mutex.h> @@ -49,6 +50,27 @@ static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat, return reset_fn; } +static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev, + struct device *dev) +{ + struct acpi_device *adev; + + if (acpi_disabled) + return -ENOENT; + + adev = ACPI_COMPANION(dev); + if (!adev) { + pr_err("VFIO: ACPI companion device not found for %s\n", + vdev->name); + return -ENODEV; + } + +#ifdef CONFIG_ACPI + vdev->acpihid = acpi_device_hid(adev); +#endif + return WARN_ON(!vdev->acpihid) ? -EINVAL : 0; +} + static bool vfio_platform_has_reset(struct vfio_platform_device *vdev) { return vdev->of_reset ? true : false; @@ -547,6 +569,37 @@ static const struct vfio_device_ops vfio_platform_ops = { .mmap = vfio_platform_mmap, }; +int vfio_platform_of_probe(struct vfio_platform_device *vdev, + struct device *dev) +{ + int ret; + + ret = device_property_read_string(dev, "compatible", + &vdev->compat); + if (ret) + pr_err("VFIO: cannot retrieve compat for %s\n", + vdev->name); + + return ret; +} + +/* + * There can be two kernel build combinations. One build where + * ACPI is not selected in Kconfig and another one with the ACPI Kconfig. + * + * In the first case, vfio_platform_acpi_probe will return since + * acpi_disabled is 1. DT user will not see any kind of messages from + * ACPI. + * + * In the second case, both DT and ACPI is compiled in but the system is + * booting with any of these combinations. + * + * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine + * terminates immediately without any messages. + * + * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are + * valid checks. We cannot claim that this system is DT. + */ int vfio_platform_probe_common(struct vfio_platform_device *vdev, struct device *dev) { @@ -556,11 +609,12 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev, if (!vdev) return -EINVAL; - ret = device_property_read_string(dev, "compatible", &vdev->compat); - if (ret) { - pr_err("VFIO: cannot retrieve compat for %s\n", vdev->name); - return -EINVAL; - } + ret = vfio_platform_acpi_probe(vdev, dev); + if (ret) + ret = vfio_platform_of_probe(vdev, dev); + + if (ret) + return ret; vdev->device = dev; diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h index 71ed7d1c1b7d..ba9e4f8b0746 100644 --- a/drivers/vfio/platform/vfio_platform_private.h +++ b/drivers/vfio/platform/vfio_platform_private.h @@ -58,6 +58,7 @@ struct vfio_platform_device { struct mutex igate; struct module *parent_module; const char *compat; + const char *acpihid; struct module *reset_module; struct device *device; |