Message-ID: <d7kv4dlv34ieh6o4wyb53wxwbiphbtlnn65g3tnxzjxilrdxu5@zrxlmhx2lye6>
Date: Fri, 6 Feb 2026 00:17:54 +0530
From: Anirudh Rayabharam <anirudh@...rudhrb.com>
To: Mukesh R <mrathor@...ux.microsoft.com>
Cc: linux-kernel@...r.kernel.org, linux-hyperv@...r.kernel.org, 
	linux-arm-kernel@...ts.infradead.org, iommu@...ts.linux.dev, linux-pci@...r.kernel.org, 
	linux-arch@...r.kernel.org, kys@...rosoft.com, haiyangz@...rosoft.com, wei.liu@...nel.org, 
	decui@...rosoft.com, longli@...rosoft.com, catalin.marinas@....com, will@...nel.org, 
	tglx@...utronix.de, mingo@...hat.com, bp@...en8.de, dave.hansen@...ux.intel.com, 
	hpa@...or.com, joro@...tes.org, lpieralisi@...nel.org, kwilczynski@...nel.org, 
	mani@...nel.org, robh@...nel.org, bhelgaas@...gle.com, arnd@...db.de, 
	nunodasneves@...ux.microsoft.com, mhklinux@...look.com, romank@...ux.microsoft.com
Subject: Re: [PATCH v0 02/15] x86/hyperv: cosmetic changes in irqdomain.c for
 readability

On Mon, Jan 19, 2026 at 10:42:17PM -0800, Mukesh R wrote:
> From: Mukesh Rathor <mrathor@...ux.microsoft.com>
> 
> Make cosmetic changes:
>  o Rename struct pci_dev *dev to *pdev since there are cases of
>    struct device *dev in the file and all over the kernel
>  o Rename hv_build_pci_dev_id to hv_build_devid_type_pci in anticipation
>    of building different types of device ids
>  o Fix checkpatch.pl issues with return and extraneous printk
>  o Replace spaces with tabs
>  o Rename struct hv_devid *xxx to struct hv_devid *hv_devid given code
>    paths involve many types of device ids
>  o Fix indentation in a large if block by using goto.
> 
> There are no functional changes.
> 
> Signed-off-by: Mukesh Rathor <mrathor@...ux.microsoft.com>
> ---
>  arch/x86/hyperv/irqdomain.c | 197 +++++++++++++++++++-----------------
>  1 file changed, 103 insertions(+), 94 deletions(-)
> 
> diff --git a/arch/x86/hyperv/irqdomain.c b/arch/x86/hyperv/irqdomain.c
> index c3ba12b1bc07..f6b61483b3b8 100644
> --- a/arch/x86/hyperv/irqdomain.c
> +++ b/arch/x86/hyperv/irqdomain.c
> @@ -1,5 +1,4 @@
>  // SPDX-License-Identifier: GPL-2.0
> -
>  /*
>   * Irqdomain for Linux to run as the root partition on Microsoft Hypervisor.
>   *
> @@ -14,8 +13,8 @@
>  #include <linux/irqchip/irq-msi-lib.h>
>  #include <asm/mshyperv.h>
>  
> -static int hv_map_interrupt(union hv_device_id device_id, bool level,
> -		int cpu, int vector, struct hv_interrupt_entry *entry)
> +static int hv_map_interrupt(union hv_device_id hv_devid, bool level,
> +		int cpu, int vector, struct hv_interrupt_entry *ret_entry)
>  {
>  	struct hv_input_map_device_interrupt *input;
>  	struct hv_output_map_device_interrupt *output;
> @@ -32,7 +31,7 @@ static int hv_map_interrupt(union hv_device_id device_id, bool level,
>  	intr_desc = &input->interrupt_descriptor;
>  	memset(input, 0, sizeof(*input));
>  	input->partition_id = hv_current_partition_id;
> -	input->device_id = device_id.as_uint64;
> +	input->device_id = hv_devid.as_uint64;
>  	intr_desc->interrupt_type = HV_X64_INTERRUPT_TYPE_FIXED;
>  	intr_desc->vector_count = 1;
>  	intr_desc->target.vector = vector;
> @@ -44,7 +43,7 @@ static int hv_map_interrupt(union hv_device_id device_id, bool level,
>  
>  	intr_desc->target.vp_set.valid_bank_mask = 0;
>  	intr_desc->target.vp_set.format = HV_GENERIC_SET_SPARSE_4K;
> -	nr_bank = cpumask_to_vpset(&(intr_desc->target.vp_set), cpumask_of(cpu));
> +	nr_bank = cpumask_to_vpset(&intr_desc->target.vp_set, cpumask_of(cpu));
>  	if (nr_bank < 0) {
>  		local_irq_restore(flags);
>  		pr_err("%s: unable to generate VP set\n", __func__);
> @@ -61,7 +60,7 @@ static int hv_map_interrupt(union hv_device_id device_id, bool level,
>  
>  	status = hv_do_rep_hypercall(HVCALL_MAP_DEVICE_INTERRUPT, 0, var_size,
>  			input, output);
> -	*entry = output->interrupt_entry;
> +	*ret_entry = output->interrupt_entry;
>  
>  	local_irq_restore(flags);
>  
> @@ -71,21 +70,19 @@ static int hv_map_interrupt(union hv_device_id device_id, bool level,
>  	return hv_result_to_errno(status);
>  }
>  
> -static int hv_unmap_interrupt(u64 id, struct hv_interrupt_entry *old_entry)
> +static int hv_unmap_interrupt(u64 id, struct hv_interrupt_entry *irq_entry)
>  {
>  	unsigned long flags;
>  	struct hv_input_unmap_device_interrupt *input;
> -	struct hv_interrupt_entry *intr_entry;
>  	u64 status;
>  
>  	local_irq_save(flags);
>  	input = *this_cpu_ptr(hyperv_pcpu_input_arg);
>  
>  	memset(input, 0, sizeof(*input));
> -	intr_entry = &input->interrupt_entry;
>  	input->partition_id = hv_current_partition_id;
>  	input->device_id = id;
> -	*intr_entry = *old_entry;
> +	input->interrupt_entry = *irq_entry;
>  
>  	status = hv_do_hypercall(HVCALL_UNMAP_DEVICE_INTERRUPT, input, NULL);
>  	local_irq_restore(flags);
> @@ -115,67 +112,71 @@ static int get_rid_cb(struct pci_dev *pdev, u16 alias, void *data)
>  	return 0;
>  }
>  
> -static union hv_device_id hv_build_pci_dev_id(struct pci_dev *dev)
> +static union hv_device_id hv_build_devid_type_pci(struct pci_dev *pdev)
>  {
> -	union hv_device_id dev_id;
> +	int pos;
> +	union hv_device_id hv_devid;
>  	struct rid_data data = {
>  		.bridge = NULL,
> -		.rid = PCI_DEVID(dev->bus->number, dev->devfn)
> +		.rid = PCI_DEVID(pdev->bus->number, pdev->devfn)
>  	};
>  
> -	pci_for_each_dma_alias(dev, get_rid_cb, &data);
> +	pci_for_each_dma_alias(pdev, get_rid_cb, &data);
>  
> -	dev_id.as_uint64 = 0;
> -	dev_id.device_type = HV_DEVICE_TYPE_PCI;
> -	dev_id.pci.segment = pci_domain_nr(dev->bus);
> +	hv_devid.as_uint64 = 0;
> +	hv_devid.device_type = HV_DEVICE_TYPE_PCI;
> +	hv_devid.pci.segment = pci_domain_nr(pdev->bus);
>  
> -	dev_id.pci.bdf.bus = PCI_BUS_NUM(data.rid);
> -	dev_id.pci.bdf.device = PCI_SLOT(data.rid);
> -	dev_id.pci.bdf.function = PCI_FUNC(data.rid);
> -	dev_id.pci.source_shadow = HV_SOURCE_SHADOW_NONE;
> +	hv_devid.pci.bdf.bus = PCI_BUS_NUM(data.rid);
> +	hv_devid.pci.bdf.device = PCI_SLOT(data.rid);
> +	hv_devid.pci.bdf.function = PCI_FUNC(data.rid);
> +	hv_devid.pci.source_shadow = HV_SOURCE_SHADOW_NONE;
>  
> -	if (data.bridge) {
> -		int pos;
> +	if (data.bridge == NULL)
> +		goto out;
>  
> -		/*
> -		 * Microsoft Hypervisor requires a bus range when the bridge is
> -		 * running in PCI-X mode.
> -		 *
> -		 * To distinguish conventional vs PCI-X bridge, we can check
> -		 * the bridge's PCI-X Secondary Status Register, Secondary Bus
> -		 * Mode and Frequency bits. See PCI Express to PCI/PCI-X Bridge
> -		 * Specification Revision 1.0 5.2.2.1.3.
> -		 *
> -		 * Value zero means it is in conventional mode, otherwise it is
> -		 * in PCI-X mode.
> -		 */
> +	/*
> +	 * Microsoft Hypervisor requires a bus range when the bridge is
> +	 * running in PCI-X mode.
> +	 *
> +	 * To distinguish conventional vs PCI-X bridge, we can check
> +	 * the bridge's PCI-X Secondary Status Register, Secondary Bus
> +	 * Mode and Frequency bits. See PCI Express to PCI/PCI-X Bridge
> +	 * Specification Revision 1.0 5.2.2.1.3.
> +	 *
> +	 * Value zero means it is in conventional mode, otherwise it is
> +	 * in PCI-X mode.
> +	 */
>  
> -		pos = pci_find_capability(data.bridge, PCI_CAP_ID_PCIX);
> -		if (pos) {
> -			u16 status;
> +	pos = pci_find_capability(data.bridge, PCI_CAP_ID_PCIX);
> +	if (pos) {
> +		u16 status;
>  
> -			pci_read_config_word(data.bridge, pos +
> -					PCI_X_BRIDGE_SSTATUS, &status);
> +		pci_read_config_word(data.bridge, pos + PCI_X_BRIDGE_SSTATUS,
> +				     &status);
>  
> -			if (status & PCI_X_SSTATUS_FREQ) {
> -				/* Non-zero, PCI-X mode */
> -				u8 sec_bus, sub_bus;
> +		if (status & PCI_X_SSTATUS_FREQ) {
> +			/* Non-zero, PCI-X mode */
> +			u8 sec_bus, sub_bus;
>  
> -				dev_id.pci.source_shadow = HV_SOURCE_SHADOW_BRIDGE_BUS_RANGE;
> +			hv_devid.pci.source_shadow =
> +					     HV_SOURCE_SHADOW_BRIDGE_BUS_RANGE;
>  
> -				pci_read_config_byte(data.bridge, PCI_SECONDARY_BUS, &sec_bus);
> -				dev_id.pci.shadow_bus_range.secondary_bus = sec_bus;
> -				pci_read_config_byte(data.bridge, PCI_SUBORDINATE_BUS, &sub_bus);
> -				dev_id.pci.shadow_bus_range.subordinate_bus = sub_bus;
> -			}
> +			pci_read_config_byte(data.bridge, PCI_SECONDARY_BUS,
> +					     &sec_bus);
> +			hv_devid.pci.shadow_bus_range.secondary_bus = sec_bus;
> +			pci_read_config_byte(data.bridge, PCI_SUBORDINATE_BUS,
> +					     &sub_bus);
> +			hv_devid.pci.shadow_bus_range.subordinate_bus = sub_bus;
>  		}
>  	}
>  
> -	return dev_id;
> +out:
> +	return hv_devid;
>  }
>  
> -/**
> - * hv_map_msi_interrupt() - "Map" the MSI IRQ in the hypervisor.
> +/*
> + * hv_map_msi_interrupt() - Map the MSI IRQ in the hypervisor.
>   * @data:      Describes the IRQ
>   * @out_entry: Hypervisor (MSI) interrupt entry (can be NULL)
>   *
> @@ -188,22 +189,23 @@ int hv_map_msi_interrupt(struct irq_data *data,
>  {
>  	struct irq_cfg *cfg = irqd_cfg(data);
>  	struct hv_interrupt_entry dummy;
> -	union hv_device_id device_id;
> +	union hv_device_id hv_devid;
>  	struct msi_desc *msidesc;
> -	struct pci_dev *dev;
> +	struct pci_dev *pdev;
>  	int cpu;
>  
>  	msidesc = irq_data_get_msi_desc(data);
> -	dev = msi_desc_to_pci_dev(msidesc);
> -	device_id = hv_build_pci_dev_id(dev);
> +	pdev = msi_desc_to_pci_dev(msidesc);
> +	hv_devid = hv_build_devid_type_pci(pdev);
>  	cpu = cpumask_first(irq_data_get_effective_affinity_mask(data));
>  
> -	return hv_map_interrupt(device_id, false, cpu, cfg->vector,
> +	return hv_map_interrupt(hv_devid, false, cpu, cfg->vector,
>  				out_entry ? out_entry : &dummy);
>  }
>  EXPORT_SYMBOL_GPL(hv_map_msi_interrupt);
>  
> -static inline void entry_to_msi_msg(struct hv_interrupt_entry *entry, struct msi_msg *msg)
> +static void entry_to_msi_msg(struct hv_interrupt_entry *entry,
> +			     struct msi_msg *msg)
>  {
>  	/* High address is always 0 */
>  	msg->address_hi = 0;
> @@ -211,17 +213,19 @@ static inline void entry_to_msi_msg(struct hv_interrupt_entry *entry, struct msi
>  	msg->data = entry->msi_entry.data.as_uint32;
>  }
>  
> -static int hv_unmap_msi_interrupt(struct pci_dev *dev, struct hv_interrupt_entry *old_entry);
> +static int hv_unmap_msi_interrupt(struct pci_dev *pdev,
> +				  struct hv_interrupt_entry *irq_entry);
> +
>  static void hv_irq_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
>  {
>  	struct hv_interrupt_entry *stored_entry;
>  	struct irq_cfg *cfg = irqd_cfg(data);
>  	struct msi_desc *msidesc;
> -	struct pci_dev *dev;
> +	struct pci_dev *pdev;
>  	int ret;
>  
>  	msidesc = irq_data_get_msi_desc(data);
> -	dev = msi_desc_to_pci_dev(msidesc);
> +	pdev = msi_desc_to_pci_dev(msidesc);
>  
>  	if (!cfg) {
>  		pr_debug("%s: cfg is NULL", __func__);
> @@ -240,7 +244,7 @@ static void hv_irq_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
>  		stored_entry = data->chip_data;
>  		data->chip_data = NULL;
>  
> -		ret = hv_unmap_msi_interrupt(dev, stored_entry);
> +		ret = hv_unmap_msi_interrupt(pdev, stored_entry);
>  
>  		kfree(stored_entry);
>  
> @@ -249,10 +253,8 @@ static void hv_irq_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
>  	}
>  
>  	stored_entry = kzalloc(sizeof(*stored_entry), GFP_ATOMIC);
> -	if (!stored_entry) {
> -		pr_debug("%s: failed to allocate chip data\n", __func__);
> +	if (!stored_entry)
>  		return;
> -	}
>  
>  	ret = hv_map_msi_interrupt(data, stored_entry);
>  	if (ret) {
> @@ -262,18 +264,21 @@ static void hv_irq_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
>  
>  	data->chip_data = stored_entry;
>  	entry_to_msi_msg(data->chip_data, msg);
> -
> -	return;
>  }
>  
> -static int hv_unmap_msi_interrupt(struct pci_dev *dev, struct hv_interrupt_entry *old_entry)
> +static int hv_unmap_msi_interrupt(struct pci_dev *pdev,
> +				  struct hv_interrupt_entry *irq_entry)
>  {
> -	return hv_unmap_interrupt(hv_build_pci_dev_id(dev).as_uint64, old_entry);
> +	union hv_device_id hv_devid;
> +
> +	hv_devid = hv_build_devid_type_pci(pdev);
> +	return hv_unmap_interrupt(hv_devid.as_uint64, irq_entry);
>  }
>  
> -static void hv_teardown_msi_irq(struct pci_dev *dev, struct irq_data *irqd)
> +/* NB: during map, hv_interrupt_entry is saved via data->chip_data */
> +static void hv_teardown_msi_irq(struct pci_dev *pdev, struct irq_data *irqd)
>  {
> -	struct hv_interrupt_entry old_entry;
> +	struct hv_interrupt_entry irq_entry;
>  	struct msi_msg msg;
>  
>  	if (!irqd->chip_data) {
> @@ -281,13 +286,13 @@ static void hv_teardown_msi_irq(struct pci_dev *dev, struct irq_data *irqd)
>  		return;
>  	}
>  
> -	old_entry = *(struct hv_interrupt_entry *)irqd->chip_data;
> -	entry_to_msi_msg(&old_entry, &msg);
> +	irq_entry = *(struct hv_interrupt_entry *)irqd->chip_data;
> +	entry_to_msi_msg(&irq_entry, &msg);
>  
>  	kfree(irqd->chip_data);
>  	irqd->chip_data = NULL;
>  
> -	(void)hv_unmap_msi_interrupt(dev, &old_entry);
> +	(void)hv_unmap_msi_interrupt(pdev, &irq_entry);
>  }
>  
>  /*
> @@ -302,7 +307,8 @@ static struct irq_chip hv_pci_msi_controller = {
>  };
>  
>  static bool hv_init_dev_msi_info(struct device *dev, struct irq_domain *domain,
> -				 struct irq_domain *real_parent, struct msi_domain_info *info)
> +				 struct irq_domain *real_parent,
> +				 struct msi_domain_info *info)
>  {
>  	struct irq_chip *chip = info->chip;
>  
> @@ -317,7 +323,8 @@ static bool hv_init_dev_msi_info(struct device *dev, struct irq_domain *domain,
>  }
>  
>  #define HV_MSI_FLAGS_SUPPORTED	(MSI_GENERIC_FLAGS_MASK | MSI_FLAG_PCI_MSIX)
> -#define HV_MSI_FLAGS_REQUIRED	(MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS)
> +#define HV_MSI_FLAGS_REQUIRED	(MSI_FLAG_USE_DEF_DOM_OPS |	\
> +				 MSI_FLAG_USE_DEF_CHIP_OPS)
>  
>  static struct msi_parent_ops hv_msi_parent_ops = {
>  	.supported_flags	= HV_MSI_FLAGS_SUPPORTED,
> @@ -329,14 +336,13 @@ static struct msi_parent_ops hv_msi_parent_ops = {
>  	.init_dev_msi_info	= hv_init_dev_msi_info,
>  };
>  
> -static int hv_msi_domain_alloc(struct irq_domain *d, unsigned int virq, unsigned int nr_irqs,
> -			       void *arg)
> +static int hv_msi_domain_alloc(struct irq_domain *d, unsigned int virq,
> +			       unsigned int nr_irqs, void *arg)
>  {
>  	/*
> -	 * TODO: The allocation bits of hv_irq_compose_msi_msg(), i.e. everything except
> -	 * entry_to_msi_msg() should be in here.
> +	 * TODO: The allocation bits of hv_irq_compose_msi_msg(), i.e.
> +	 *	 everything except entry_to_msi_msg() should be in here.
>  	 */
> -
>  	int ret;
>  
>  	ret = irq_domain_alloc_irqs_parent(d, virq, nr_irqs, arg);
> @@ -344,13 +350,15 @@ static int hv_msi_domain_alloc(struct irq_domain *d, unsigned int virq, unsigned
>  		return ret;
>  
>  	for (int i = 0; i < nr_irqs; ++i) {
> -		irq_domain_set_info(d, virq + i, 0, &hv_pci_msi_controller, NULL,
> -				    handle_edge_irq, NULL, "edge");
> +		irq_domain_set_info(d, virq + i, 0, &hv_pci_msi_controller,
> +				    NULL, handle_edge_irq, NULL, "edge");
>  	}
> +
>  	return 0;
>  }
>  
> -static void hv_msi_domain_free(struct irq_domain *d, unsigned int virq, unsigned int nr_irqs)
> +static void hv_msi_domain_free(struct irq_domain *d, unsigned int virq,
> +			       unsigned int nr_irqs)
>  {
>  	for (int i = 0; i < nr_irqs; ++i) {
>  		struct irq_data *irqd = irq_domain_get_irq_data(d, virq);
> @@ -362,6 +370,7 @@ static void hv_msi_domain_free(struct irq_domain *d, unsigned int virq, unsigned
>  
>  		hv_teardown_msi_irq(to_pci_dev(desc->dev), irqd);
>  	}
> +
>  	irq_domain_free_irqs_top(d, virq, nr_irqs);
>  }
>  
> @@ -394,25 +403,25 @@ struct irq_domain * __init hv_create_pci_msi_domain(void)
>  
>  int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *entry)
>  {
> -	union hv_device_id device_id;
> +	union hv_device_id hv_devid;
>  
> -	device_id.as_uint64 = 0;
> -	device_id.device_type = HV_DEVICE_TYPE_IOAPIC;
> -	device_id.ioapic.ioapic_id = (u8)ioapic_id;
> +	hv_devid.as_uint64 = 0;
> +	hv_devid.device_type = HV_DEVICE_TYPE_IOAPIC;
> +	hv_devid.ioapic.ioapic_id = (u8)ioapic_id;
>  
> -	return hv_unmap_interrupt(device_id.as_uint64, entry);
> +	return hv_unmap_interrupt(hv_devid.as_uint64, entry);
>  }
>  EXPORT_SYMBOL_GPL(hv_unmap_ioapic_interrupt);
>  
>  int hv_map_ioapic_interrupt(int ioapic_id, bool level, int cpu, int vector,
>  		struct hv_interrupt_entry *entry)
>  {
> -	union hv_device_id device_id;
> +	union hv_device_id hv_devid;
>  
> -	device_id.as_uint64 = 0;
> -	device_id.device_type = HV_DEVICE_TYPE_IOAPIC;
> -	device_id.ioapic.ioapic_id = (u8)ioapic_id;
> +	hv_devid.as_uint64 = 0;
> +	hv_devid.device_type = HV_DEVICE_TYPE_IOAPIC;
> +	hv_devid.ioapic.ioapic_id = (u8)ioapic_id;
>  
> -	return hv_map_interrupt(device_id, level, cpu, vector, entry);
> +	return hv_map_interrupt(hv_devid, level, cpu, vector, entry);
>  }
>  EXPORT_SYMBOL_GPL(hv_map_ioapic_interrupt);
> -- 
> 2.51.2.vfs.0.1
> 

Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@...rudhrb.com>

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