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.
When ACPI is enabled, the change will query the presence of _RST method and will call it instead of querying an external reset driver. Signed-off-by: Sinan Kaya <[email protected]> --- drivers/vfio/platform/vfio_platform_common.c | 176 +++++++++++++++++++++----- drivers/vfio/platform/vfio_platform_private.h | 7 +- 2 files changed, 147 insertions(+), 36 deletions(-) diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c index e65b142..528ec04 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> @@ -41,7 +42,7 @@ static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat, if (!strcmp(iter->compat, compat) && try_module_get(iter->owner)) { *module = iter->owner; - reset_fn = iter->reset; + reset_fn = iter->of_reset; break; } } @@ -49,20 +50,111 @@ static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat, return reset_fn; } -static void vfio_platform_get_reset(struct vfio_platform_device *vdev) + +#ifdef CONFIG_ACPI +int vfio_platform_acpi_probe(struct vfio_platform_device *vdev, + struct device *dev) { - vdev->reset = vfio_platform_lookup_reset(vdev->compat, - &vdev->reset_module); - if (!vdev->reset) { - request_module("vfio-reset:%s", vdev->compat); - vdev->reset = vfio_platform_lookup_reset(vdev->compat, - &vdev->reset_module); + struct acpi_device *adev = ACPI_COMPANION(dev); + + if (acpi_disabled) + return -ENODEV; + + if (!adev) + return -ENODEV; + + vdev->acpihid = acpi_device_hid(adev); + if (!vdev->acpihid) { + pr_err("VFIO: cannot find ACPI HID for %s\n", + vdev->name); + return -ENODEV; } + return 0; +} + +static int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev) +{ + struct device *dev = vdev->device; + acpi_handle handle = ACPI_HANDLE(dev); + acpi_status acpi_ret; + unsigned long long val; + + acpi_ret = acpi_evaluate_integer(handle, "_RST", NULL, &val); + if (ACPI_FAILURE(acpi_ret)) + return -EINVAL; + + return 0; +} + +static int vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev) +{ + struct device *dev = vdev->device; + acpi_handle handle = ACPI_HANDLE(dev); + + if (acpi_has_method(handle, "_RST")) + return 0; + + return -EINVAL; +} +#else +int vfio_platform_acpi_probe(struct vfio_platform_device *vdev, + struct device *dev) +{ + return -EINVAL; +} + +static int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev) +{ + return -EINVAL; +} + +static int vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev) +{ + return -EINVAL; +} +#endif + +static int vfio_platform_has_reset(struct vfio_platform_device *vdev) +{ + if (vdev->acpihid) + return vfio_platform_acpi_has_reset(vdev); + + if (vdev->of_reset) + return 0; + + return -EINVAL; +} + +static int vfio_platform_get_reset(struct vfio_platform_device *vdev) +{ + int rc; + + if (vdev->acpihid) + return vfio_platform_acpi_has_reset(vdev); + + vdev->of_reset = vfio_platform_lookup_reset(vdev->compat, + &vdev->reset_module); + if (vdev->of_reset) + return 0; + + rc = request_module("vfio-reset:%s", vdev->compat); + if (rc) + return rc; + + vdev->of_reset = vfio_platform_lookup_reset(vdev->compat, + &vdev->reset_module); + if (vdev->of_reset) + return 0; + + return -EINVAL; } static void vfio_platform_put_reset(struct vfio_platform_device *vdev) { - if (vdev->reset) + if (vdev->acpihid) + return; + + if (vdev->of_reset) module_put(vdev->reset_module); } @@ -134,6 +226,20 @@ static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev) kfree(vdev->regions); } +static int vfio_platform_call_reset(struct vfio_platform_device *vdev) +{ + if (vdev->of_reset) { + dev_info(vdev->device, "reset\n"); + vdev->of_reset(vdev); + return 0; + } else if (vdev->acpihid) { + return vfio_platform_acpi_call_reset(vdev); + } + + dev_warn(vdev->device, "no reset function found!\n"); + return -EINVAL; +} + static void vfio_platform_release(void *device_data) { struct vfio_platform_device *vdev = device_data; @@ -141,12 +247,7 @@ static void vfio_platform_release(void *device_data) mutex_lock(&driver_lock); if (!(--vdev->refcnt)) { - if (vdev->reset) { - dev_info(vdev->device, "reset\n"); - vdev->reset(vdev); - } else { - dev_warn(vdev->device, "no reset function found!\n"); - } + vfio_platform_call_reset(vdev); vfio_platform_regions_cleanup(vdev); vfio_platform_irq_cleanup(vdev); } @@ -175,12 +276,9 @@ static int vfio_platform_open(void *device_data) if (ret) goto err_irq; - if (vdev->reset) { - dev_info(vdev->device, "reset\n"); - vdev->reset(vdev); - } else { - dev_warn(vdev->device, "no reset function found!\n"); - } + ret = vfio_platform_call_reset(vdev); + if (ret) + goto err_irq; } vdev->refcnt++; @@ -213,7 +311,7 @@ static long vfio_platform_ioctl(void *device_data, if (info.argsz < minsz) return -EINVAL; - if (vdev->reset) + if (!vfio_platform_has_reset(vdev)) vdev->flags |= VFIO_DEVICE_FLAGS_RESET; info.flags = vdev->flags; info.num_regions = vdev->num_regions; @@ -312,10 +410,7 @@ static long vfio_platform_ioctl(void *device_data, return ret; } else if (cmd == VFIO_DEVICE_RESET) { - if (vdev->reset) - return vdev->reset(vdev); - else - return -EINVAL; + return vfio_platform_call_reset(vdev); } return -ENOTTY; @@ -544,6 +639,21 @@ 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; + } + return 0; +} + int vfio_platform_probe_common(struct vfio_platform_device *vdev, struct device *dev) { @@ -553,14 +663,14 @@ 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); - vdev->device = dev; + if (ret) + return ret; + vdev->device = dev; group = iommu_group_get(dev); if (!group) { pr_err("VFIO: No IOMMU group for device %s\n", vdev->name); @@ -611,7 +721,7 @@ void vfio_platform_unregister_reset(const char *compat, mutex_lock(&driver_lock); list_for_each_entry_safe(iter, temp, &reset_list, link) { - if (!strcmp(iter->compat, compat) && (iter->reset == fn)) { + if (!strcmp(iter->compat, compat) && (iter->of_reset == fn)) { list_del(&iter->link); break; } diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h index 42816dd..ba9e4f8 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; @@ -71,7 +72,7 @@ struct vfio_platform_device { struct resource* (*get_resource)(struct vfio_platform_device *vdev, int i); int (*get_irq)(struct vfio_platform_device *vdev, int i); - int (*reset)(struct vfio_platform_device *vdev); + int (*of_reset)(struct vfio_platform_device *vdev); }; typedef int (*vfio_platform_reset_fn_t)(struct vfio_platform_device *vdev); @@ -80,7 +81,7 @@ struct vfio_platform_reset_node { struct list_head link; char *compat; struct module *owner; - vfio_platform_reset_fn_t reset; + vfio_platform_reset_fn_t of_reset; }; extern int vfio_platform_probe_common(struct vfio_platform_device *vdev, @@ -103,7 +104,7 @@ extern void vfio_platform_unregister_reset(const char *compat, static struct vfio_platform_reset_node __reset ## _node = { \ .owner = THIS_MODULE, \ .compat = __compat, \ - .reset = __reset, \ + .of_reset = __reset, \ }; \ __vfio_platform_register_reset(&__reset ## _node) -- 1.8.2.1
