From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 0F71822D79B; Mon, 10 Mar 2025 17:09:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741626588; cv=none; b=mVe3aiB928ZEqkhgbpofJRFxq1CRpOGXriWhhhmeCr3QWjLierbTXE/90fAtJ1RswfVN2nVQd3nouBbShTrd+casM/xH6br7b2URCp9kIbKq0CCXNVASSniHtBIF5n1Z2sWmlxEuw4iUDP7Gzcbn/H9CVGXwB6F7iRPFFugU3eA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741626588; c=relaxed/simple; bh=yVNu05pqKMvUkTRfJJGadIbGslAZMjfMrFefbqDKqXM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=k2RTmOnBwcjSlPXADnO0iaVp7lmFZjUc084/f1+etIhPO59NTbsbaPHB6QpqHtbnAklvGLGILkl0ic5kSLBJFUEdwe0Swm1XzB78IDI8vXNeggsaN7lL7zTWOxrBmQcugIX2giAshJwE3HEeCY42kWeYidOw2138bjFUreGk5Ec= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=l1AipWqa; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="l1AipWqa" Received: from [10.137.184.60] (unknown [131.107.160.188]) by linux.microsoft.com (Postfix) with ESMTPSA id 0DA692038F32; Mon, 10 Mar 2025 10:09:46 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 0DA692038F32 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1741626586; bh=ZPp0js6+jrg5sVe7XA7ERrTixZv7xjbVVvf7fRlGlAE=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=l1AipWqanSYF7uSInl5in5VBJSpUKdzXNs6Z6Cc5jMQikOncxE6pClVlB5vRa3No/ iDoZQTAoQd9hGHqs2vaxzFNRGIT6LEpWYSUp2mlFkdRWAt98W4RXVrPRI1lDqFK6Qv S3kLzNTctjFEFKHQ9Tw6wh1lVjMxr+HbU/Mq8eew= Message-ID: Date: Mon, 10 Mar 2025 10:09:45 -0700 Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH hyperv-next v5 09/11] Drivers: hv: vmbus: Introduce hv_get_vmbus_root_device() To: Tianyu Lan Cc: arnd@arndb.de, bhelgaas@google.com, bp@alien8.de, catalin.marinas@arm.com, conor+dt@kernel.org, dave.hansen@linux.intel.com, decui@microsoft.com, haiyangz@microsoft.com, hpa@zytor.com, joey.gouly@arm.com, krzk+dt@kernel.org, kw@linux.com, kys@microsoft.com, lenb@kernel.org, lpieralisi@kernel.org, manivannan.sadhasivam@linaro.org, mark.rutland@arm.com, maz@kernel.org, mingo@redhat.com, oliver.upton@linux.dev, rafael@kernel.org, robh@kernel.org, ssengar@linux.microsoft.com, sudeep.holla@arm.com, suzuki.poulose@arm.com, tglx@linutronix.de, wei.liu@kernel.org, will@kernel.org, yuzenghui@huawei.com, devicetree@vger.kernel.org, kvmarm@lists.linux.dev, linux-acpi@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, x86@kernel.org, apais@microsoft.com, benhill@microsoft.com, bperkins@microsoft.com, sunilmut@microsoft.com References: <20250307220304.247725-1-romank@linux.microsoft.com> <20250307220304.247725-10-romank@linux.microsoft.com> Content-Language: en-US From: Roman Kisel In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 3/10/2025 6:41 AM, Tianyu Lan wrote: > On Sat, Mar 8, 2025 at 6:05 AM Roman Kisel wrote: >> >> 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 > > Why change all device's parent to vmbus_root_device? > No changes from my account of the code. Please let me know if I am misunderstanding the question. > The ARM64 platform uses the device tree to enumerate vmbus > devices.. Can we find the root device via device tree? vmbus > code on the x86 use ACPI and it seems to work via ACPI. > > Right, we find it from the DT as shown in the next patch: +static struct irq_domain *hv_pci_of_irq_domain_parent(void) +{ + struct device_node *parent; + struct irq_domain *domain; + + parent = of_irq_find_parent(hv_get_vmbus_root_device()->of_node); + domain = NULL; + if (parent) { + domain = irq_find_host(parent); + of_node_put(parent); + } + + return domain; +} + and later use it for `irq_create_hierarchy()`. Please let me know if I missed anything in your question. >> --- >> 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 c8474b48dcd2..7bfafe702963 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 >> @@ -2383,7 +2390,7 @@ 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) >> @@ -2702,7 +2709,7 @@ static int __init hv_acpi_init(void) >> if (ret) >> return ret; >> >> - if (!hv_dev) { >> + if (!vmbus_root_device) { >> ret = -ENODEV; >> goto cleanup; >> } >> @@ -2733,7 +2740,7 @@ 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 7f4f8d8bdf43..1f0851fde041 100644 >> --- a/include/linux/hyperv.h >> +++ b/include/linux/hyperv.h >> @@ -1333,6 +1333,8 @@ 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 >> >> > > -- Thank you, Roman