Conceptually, we shouldn't have to build the VMBus driver to answer the question "does VMBus exist?" So, move vmbus_root_device and the functions that access it directly to hyperv.h. Also, introduce hv_set_vmbus_root_device() to allow vmbus_drv to set the root device.
Reported-by: Arnd Bergmann <[email protected]> Closes: https://lore.kernel.org/r/[email protected]/ Fixes: f1a9e67c1138 ("mshv: limit SynIC management to MSHV-owned resources") Signed-off-by: Hamza Mahfooz <[email protected]> --- drivers/hv/vmbus_drv.c | 27 ++++++--------------------- include/linux/hyperv.h | 18 ++++++++++++++++-- 2 files changed, 22 insertions(+), 23 deletions(-) diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 71f1b4d52f7f..b26e6b42fa49 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -47,9 +47,6 @@ struct vmbus_dynid { struct hv_vmbus_device_id id; }; -/* VMBus Root Device */ -static struct device *vmbus_root_device; - static int hyperv_cpuhp_online; static DEFINE_PER_CPU(long, vmbus_evt); @@ -95,18 +92,6 @@ 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); - -bool hv_vmbus_exists(void) -{ - return vmbus_root_device != NULL; -} -EXPORT_SYMBOL_GPL(hv_vmbus_exists); - static u8 channel_monitor_group(const struct vmbus_channel *channel) { return (u8)channel->offermsg.monitorid / 32; @@ -903,7 +888,7 @@ 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(vmbus_root_device) == DEV_DMA_COHERENT); + device_get_dma_attr(hv_get_vmbus_root_device()) == DEV_DMA_COHERENT); return 0; } @@ -2172,7 +2157,7 @@ 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 = vmbus_root_device; + child_device_obj->device.parent = hv_get_vmbus_root_device(); child_device_obj->device.release = vmbus_device_release; child_device_obj->device.dma_parms = &child_device_obj->dma_parms; @@ -2561,7 +2546,7 @@ static int vmbus_acpi_add(struct platform_device *pdev) struct acpi_device *ancestor; struct acpi_device *device = ACPI_COMPANION(&pdev->dev); - vmbus_root_device = &device->dev; + hv_set_vmbus_root_device(&device->dev); /* * Older versions of Hyper-V for ARM64 fail to include the _CCA @@ -2648,7 +2633,7 @@ static int vmbus_device_add(struct platform_device *pdev) struct device_node *np = pdev->dev.of_node; int ret; - vmbus_root_device = &pdev->dev; + hv_set_vmbus_root_device(&pdev->dev); ret = of_range_parser_init(&parser, np); if (ret) @@ -2969,7 +2954,7 @@ static int __init hv_acpi_init(void) if (ret) return ret; - if (!vmbus_root_device) { + if (!hv_vmbus_exists()) { ret = -ENODEV; goto cleanup; } @@ -3000,7 +2985,7 @@ static int __init hv_acpi_init(void) cleanup: platform_driver_unregister(&vmbus_platform_driver); - vmbus_root_device = NULL; + hv_set_vmbus_root_device(NULL); return ret; } diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 5459e776ec17..3e8ea7d9653c 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1302,9 +1302,23 @@ static inline void *hv_get_drvdata(struct hv_device *dev) return dev_get_drvdata(&dev->device); } -struct device *hv_get_vmbus_root_device(void); +/* Do *not* use this outside of hyperv.h */ +static struct device *__vmbus_root_device __read_mostly; -bool hv_vmbus_exists(void); +static inline void hv_set_vmbus_root_device(struct device *dev) +{ + __vmbus_root_device = dev; +} + +static inline struct device *hv_get_vmbus_root_device(void) +{ + return __vmbus_root_device; +} + +static inline bool hv_vmbus_exists(void) +{ + return hv_get_vmbus_root_device(); +} struct hv_ring_buffer_debug_info { u32 current_interrupt_mask; -- 2.54.0
