Commit efe68563 authored by Bjorn Helgaas's avatar Bjorn Helgaas
Browse files

Merge branch 'pci/msi' 

- Document sysfs "irq" attribute, which contains either the INTx IRQ (the
  intended behavior) or the first MSI IRQ (historical mistake retained for
  backwards compatibility) (Barry Song)

- Rework "irq" sysfs show function to explicitly fetch first MSI IRQ
  instead of depending on core to put it in dev->irq, to enable future core
  cleanup (Barry Song)

* pci/msi:
  PCI/sysfs: Explicitly show first MSI IRQ for 'irq'
  PCI: Document /sys/bus/pci/devices/.../irq
parents 4917f718 ac8e3cef

Documentation/ABI/testing/sysfs-bus-pci

+11 −0
Original line number Diff line number Diff line
@@ -96,6 +96,17 @@ Description: 
		This attribute indicates the mode that the irq vector named by

		the file is in (msi vs. msix)



What:		/sys/bus/pci/devices/.../irq

Date:		August 2021

Contact:	Linux PCI developers <linux-pci@vger.kernel.org>

Description:

		If a driver has enabled MSI (not MSI-X), "irq" contains the

		IRQ of the first MSI vector. Otherwise "irq" contains the

		IRQ of the legacy INTx interrupt.



		"irq" being set to 0 indicates that the device isn't

		capable of generating legacy INTx interrupts.



What:		/sys/bus/pci/devices/.../remove

Date:		January 2009

Contact:	Linux PCI developers <linux-pci@vger.kernel.org>

drivers/pci/pci-sysfs.c

+23 −1
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include <linux/slab.h>

#include <linux/vgaarb.h>

#include <linux/pm_runtime.h>

#include <linux/msi.h>

#include <linux/of.h>

#include "pci.h"
@@ -49,7 +50,28 @@ pci_config_attr(subsystem_vendor, "0x%04x\n"); 
pci_config_attr(subsystem_device, "0x%04x\n");

pci_config_attr(revision, "0x%02x\n");

pci_config_attr(class, "0x%06x\n");

pci_config_attr(irq, "%u\n");



static ssize_t irq_show(struct device *dev,

			struct device_attribute *attr,

			char *buf)

{

	struct pci_dev *pdev = to_pci_dev(dev);



#ifdef CONFIG_PCI_MSI

	/*

	 * For MSI, show the first MSI IRQ; for all other cases including

	 * MSI-X, show the legacy INTx IRQ.

	 */

	if (pdev->msi_enabled) {

		struct msi_desc *desc = first_pci_msi_entry(pdev);



		return sysfs_emit(buf, "%u\n", desc->irq);

	}

#endif



	return sysfs_emit(buf, "%u\n", pdev->irq);

}

static DEVICE_ATTR_RO(irq);



static ssize_t broken_parity_status_show(struct device *dev,

					 struct device_attribute *attr,