From ac8e3cef588c5affc6dfa7b693ec64bbf3cead6a Mon Sep 17 00:00:00 2001 From: Barry Song Date: Wed, 25 Aug 2021 18:26:35 +0800 Subject: [PATCH] PCI/sysfs: Explicitly show first MSI IRQ for 'irq' The sysfs "irq" file contains the legacy INTx IRQ. Or, if the device has MSI enabled, it contains the first MSI IRQ instead. Previously this file showed the pci_dev.irq value directly. But we'd prefer to use pci_dev.irq only for the INTx IRQ and decouple that from any MSI or MSI-X IRQs. If the device has MSI enabled, explicitly look up and show the first MSI IRQ in the sysfs "irq" file. Otherwise, show the INTx IRQ. This removes the requirement that msi_capability_init() set pci_dev.irq to the first MSI IRQ when enabling MSI and pci_msi_shutdown() restore the INTx IRQ when disabling MSI. [bhelgaas: commit log] Link: https://lore.kernel.org/r/20210825102636.52757-3-21cnbao@gmail.com Signed-off-by: Barry Song Signed-off-by: Bjorn Helgaas --- drivers/pci/pci-sysfs.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 7fb5cd17cc98..b50fe7ce234b 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #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,