Commit 5f83d633 authored by Nam Cao's avatar Nam Cao Committed by David S. Miller
Browse files

PCI: hv: Switch to msi_create_parent_irq_domain() 



Move away from the legacy MSI domain setup, switch to use
msi_create_parent_irq_domain().

While doing the conversion, I noticed that hv_compose_msi_msg() is doing
more than it is supposed to (composing message). This function also
allocates and populates struct tran_int_desc, which should be done in
hv_pcie_domain_alloc() instead. It works, but it is not the correct design.
However, I have no hardware to test such change, therefore I leave a TODO
note.

Acked-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarNam Cao <namcao@linutronix.de>
Reviewed-by: default avatarMichael Kelley <mhklinux@outlook.com>
Tested-by: default avatarMichael Kelley <mhklinux@outlook.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a6b0465b

drivers/pci/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -223,6 +223,7 @@ config PCI_HYPERV 
	tristate "Hyper-V PCI Frontend"

	depends on ((X86 && X86_64) || ARM64) && HYPERV && PCI_MSI && SYSFS

	select PCI_HYPERV_INTERFACE

	select IRQ_MSI_LIB

	help

	  The PCI device frontend driver allows the kernel to import arbitrary

	  PCI devices from a PCI backend to support PCI driver domains.

drivers/pci/controller/pci-hyperv.c

+83 −28
Original line number Diff line number Diff line
@@ -44,6 +44,7 @@ 
#include <linux/delay.h>

#include <linux/semaphore.h>

#include <linux/irq.h>

#include <linux/irqchip/irq-msi-lib.h>

#include <linux/msi.h>

#include <linux/hyperv.h>

#include <linux/refcount.h>
@@ -508,7 +509,6 @@ struct hv_pcibus_device { 
	struct list_head children;

	struct list_head dr_list;



	struct msi_domain_info msi_info;

	struct irq_domain *irq_domain;



	struct workqueue_struct *wq;
@@ -577,8 +577,7 @@ static void hv_pci_onchannelcallback(void *context); 


#ifdef CONFIG_X86

#define DELIVERY_MODE		APIC_DELIVERY_MODE_FIXED

#define FLOW_HANDLER	handle_edge_irq

#define FLOW_NAME	"edge"

#define HV_MSI_CHIP_FLAGS	MSI_CHIP_FLAG_SET_ACK



static int hv_pci_irqchip_init(void)

{
@@ -723,8 +722,7 @@ static void hv_arch_irq_unmask(struct irq_data *data) 
#define HV_PCI_MSI_SPI_START	64

#define HV_PCI_MSI_SPI_NR	(1020 - HV_PCI_MSI_SPI_START)

#define DELIVERY_MODE		0

#define FLOW_HANDLER		NULL

#define FLOW_NAME		NULL

#define HV_MSI_CHIP_FLAGS	MSI_CHIP_FLAG_SET_EOI

#define hv_msi_prepare		NULL



struct hv_pci_chip_data {
@@ -1687,7 +1685,7 @@ static void hv_msi_free(struct irq_domain *domain, struct msi_domain_info *info, 
	struct msi_desc *msi = irq_data_get_msi_desc(irq_data);



	pdev = msi_desc_to_pci_dev(msi);

	hbus = info->data;

	hbus = domain->host_data;

	int_desc = irq_data_get_irq_chip_data(irq_data);

	if (!int_desc)

		return;
@@ -1705,7 +1703,6 @@ static void hv_msi_free(struct irq_domain *domain, struct msi_domain_info *info, 


static void hv_irq_mask(struct irq_data *data)

{

	pci_msi_mask_irq(data);

	if (data->parent_data->chip->irq_mask)

		irq_chip_mask_parent(data);

}
@@ -1716,7 +1713,6 @@ static void hv_irq_unmask(struct irq_data *data) 


	if (data->parent_data->chip->irq_unmask)

		irq_chip_unmask_parent(data);

	pci_msi_unmask_irq(data);

}



struct compose_comp_ctxt {
@@ -2101,25 +2097,87 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) 
	msg->data = 0;

}



static bool hv_pcie_init_dev_msi_info(struct device *dev, struct irq_domain *domain,

				      struct irq_domain *real_parent, struct msi_domain_info *info)

{

	struct irq_chip *chip = info->chip;



	if (!msi_lib_init_dev_msi_info(dev, domain, real_parent, info))

		return false;



	info->ops->msi_prepare = hv_msi_prepare;



	chip->irq_set_affinity = irq_chip_set_affinity_parent;



	if (IS_ENABLED(CONFIG_X86))

		chip->flags |= IRQCHIP_MOVE_DEFERRED;



	return true;

}



#define HV_PCIE_MSI_FLAGS_REQUIRED (MSI_FLAG_USE_DEF_DOM_OPS		| \

				    MSI_FLAG_USE_DEF_CHIP_OPS		| \

				    MSI_FLAG_PCI_MSI_MASK_PARENT)

#define HV_PCIE_MSI_FLAGS_SUPPORTED (MSI_FLAG_MULTI_PCI_MSI		| \

				     MSI_FLAG_PCI_MSIX			| \

				     MSI_FLAG_PCI_MSIX_ALLOC_DYN	| \

				     MSI_GENERIC_FLAGS_MASK)



static const struct msi_parent_ops hv_pcie_msi_parent_ops = {

	.required_flags		= HV_PCIE_MSI_FLAGS_REQUIRED,

	.supported_flags	= HV_PCIE_MSI_FLAGS_SUPPORTED,

	.bus_select_token	= DOMAIN_BUS_PCI_MSI,

	.chip_flags		= HV_MSI_CHIP_FLAGS,

	.prefix			= "HV-",

	.init_dev_msi_info	= hv_pcie_init_dev_msi_info,

};



/* HW Interrupt Chip Descriptor */

static struct irq_chip hv_msi_irq_chip = {

	.name			= "Hyper-V PCIe MSI",

	.irq_compose_msi_msg	= hv_compose_msi_msg,

	.irq_set_affinity	= irq_chip_set_affinity_parent,

#ifdef CONFIG_X86

	.irq_ack		= irq_chip_ack_parent,

	.flags			= IRQCHIP_MOVE_DEFERRED,

#elif defined(CONFIG_ARM64)

	.irq_eoi		= irq_chip_eoi_parent,

#endif

	.irq_mask		= hv_irq_mask,

	.irq_unmask		= hv_irq_unmask,

};



static struct msi_domain_ops hv_msi_ops = {

	.msi_prepare	= hv_msi_prepare,

	.msi_free	= hv_msi_free,

	.prepare_desc	= pci_msix_prepare_desc,

static int hv_pcie_domain_alloc(struct irq_domain *d, unsigned int virq, unsigned int nr_irqs,

			       void *arg)

{

	/*

	 * TODO: Allocating and populating struct tran_int_desc in hv_compose_msi_msg()

	 * should be moved here.

	 */

	int ret;



	ret = irq_domain_alloc_irqs_parent(d, virq, nr_irqs, arg);

	if (ret < 0)

		return ret;



	for (int i = 0; i < nr_irqs; i++) {

		irq_domain_set_hwirq_and_chip(d, virq + i, 0, &hv_msi_irq_chip, NULL);

		if (IS_ENABLED(CONFIG_X86))

			__irq_set_handler(virq + i, handle_edge_irq, 0, "edge");

	}



	return 0;

}



static void hv_pcie_domain_free(struct irq_domain *d, unsigned int virq, unsigned int nr_irqs)

{

	struct msi_domain_info *info = d->host_data;



	for (int i = 0; i < nr_irqs; i++)

		hv_msi_free(d, info, virq + i);



	irq_domain_free_irqs_top(d, virq, nr_irqs);

}



static const struct irq_domain_ops hv_pcie_domain_ops = {

	.alloc	= hv_pcie_domain_alloc,

	.free	= hv_pcie_domain_free,

};



/**
@@ -2137,17 +2195,14 @@ static struct msi_domain_ops hv_msi_ops = { 
 */

static int hv_pcie_init_irq_domain(struct hv_pcibus_device *hbus)

{

	hbus->msi_info.chip = &hv_msi_irq_chip;

	hbus->msi_info.ops = &hv_msi_ops;

	hbus->msi_info.flags = (MSI_FLAG_USE_DEF_DOM_OPS |

		MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_MULTI_PCI_MSI |

		MSI_FLAG_PCI_MSIX | MSI_FLAG_PCI_MSIX_ALLOC_DYN);

	hbus->msi_info.handler = FLOW_HANDLER;

	hbus->msi_info.handler_name = FLOW_NAME;

	hbus->msi_info.data = hbus;

	hbus->irq_domain = pci_msi_create_irq_domain(hbus->fwnode,

						     &hbus->msi_info,

						     hv_pci_get_root_domain());

	struct irq_domain_info info = {

		.fwnode		= hbus->fwnode,

		.ops		= &hv_pcie_domain_ops,

		.host_data	= hbus,

		.parent		= hv_pci_get_root_domain(),

	};



	hbus->irq_domain = msi_create_parent_irq_domain(&info, &hv_pcie_msi_parent_ops);

	if (!hbus->irq_domain) {

		dev_err(&hbus->hdev->device,

			"Failed to build an MSI IRQ domain\n");