[PATCH hyperv-next v6 09/11] Drivers: hv: vmbus: Introduce hv_get_vmbus_root_device()

Roman Kisel
2025-03-15T00:19:36Z

The ARM64 PCI code for hyperv needs to know the VMBus root
device, and it is private.

Provide a function that returns it. Rename it from "hv_dev"
as "hv_dev" as a symbol is very overloaded. No functional
changes.

Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
---
drivers/hv/vmbus_drv.c | 23 +++++++++++++++--------
include/linux/hyperv.h | 2 ++
2 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index e8f2c3e92d1f..df18b4070b01 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -45,7 +45,8 @@ struct vmbus_dynid {
struct hv_vmbus_device_id id;
};

-static struct device *hv_dev;
+/* VMBus Root Device */
+static struct device *vmbus_root_device;

static int hyperv_cpuhp_online;

@@ -80,9 +81,15 @@ static struct resource *fb_mmio;
static struct resource *hyperv_mmio;
static DEFINE_MUTEX(hyperv_mmio_lock);

+struct device *hv_get_vmbus_root_device(void)
+{
+ return vmbus_root_device;
+}
+EXPORT_SYMBOL_GPL(hv_get_vmbus_root_device);
+
static int vmbus_exists(void)
{
- if (hv_dev == NULL)
+ if (vmbus_root_device == NULL)
return -ENODEV;

return 0;
@@ -861,7 +868,7 @@ static int vmbus_dma_configure(struct device *child_device)
* On x86/x64 coherence is assumed and these calls have no effect.
*/
hv_setup_dma_ops(child_device,
- device_get_dma_attr(hv_dev) == DEV_DMA_COHERENT);
+ device_get_dma_attr(vmbus_root_device) == DEV_DMA_COHERENT);
return 0;
}

@@ -1930,7 +1937,7 @@ int vmbus_device_register(struct hv_device *child_device_obj)
&child_device_obj->channel->offermsg.offer.if_instance);

child_device_obj->device.bus = &hv_bus;
- child_device_obj->device.parent = hv_dev;
+ child_device_obj->device.parent = vmbus_root_device;
child_device_obj->device.release = vmbus_device_release;

child_device_obj->device.dma_parms = &child_device_obj->dma_parms;
@@ -2292,7 +2299,7 @@ static int vmbus_acpi_add(struct platform_device *pdev)
struct acpi_device *ancestor;
struct acpi_device *device = ACPI_COMPANION(&pdev->dev);

- hv_dev = &device->dev;
+ vmbus_root_device = &device->dev;

/*
* Older versions of Hyper-V for ARM64 fail to include the _CCA
@@ -2378,7 +2385,7 @@ static int vmbus_device_add(struct platform_device *pdev)
struct device_node *np = pdev->dev.of_node;
int ret;

- hv_dev = &pdev->dev;
+ vmbus_root_device = &pdev->dev;

ret = of_range_parser_init(&parser, np);
if (ret)
@@ -2696,7 +2703,7 @@ static int __init hv_acpi_init(void)
if (ret)
return ret;

- if (!hv_dev) {
+ if (!vmbus_root_device) {
ret = -ENODEV;
goto cleanup;
}
@@ -2727,7 +2734,7 @@ static int __init hv_acpi_init(void)

cleanup:
platform_driver_unregister(&vmbus_platform_driver);
- hv_dev = NULL;
+ vmbus_root_device = NULL;
return ret;
}

diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 675959fb97ba..1f310fbbc4f9 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1277,6 +1277,8 @@ static inline void *hv_get_drvdata(struct hv_device *dev)
return dev_get_drvdata(&dev->device);
}

+struct device *hv_get_vmbus_root_device(void);
+
struct hv_ring_buffer_debug_info {
u32 current_interrupt_mask;
u32 current_read_index;
--
2.43.0