serial: 8250_pci: Implement MSI(-X) support (8428413b) · Commits · 戴 / test

There may be setups, where legacy interrupts are not available. This is the caese, e.g., when Linux runs as guest (aka. non-root cell) of the partitioning hypervisor Jailhouse. There, only MSI(-X) interrupts are available for guests. But the 8250_pci driver currently only supports legacy ints. So let's enable MSI(-X) interrupts. Nevertheless, this needs to handled with care: while many 8250 devices actually claim to support MSI(-X) interrupts it should not be enabled be default. I had at least one device in my hands with broken MSI implementation. So better introduce a whitelist with devices that are known to support MSI(-X) interrupts. I tested all devices mentioned in the patch. Signed-off-by:

Ralf Ramsauer <ralf.ramsauer@oth-regensburg.de> Link: https://lore.kernel.org/r/20190812112152.693622-1-ralf.ramsauer@oth-regensburg.de Signed-off-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250_pci.c

+26 −1

Original line number	Diff line number	Diff line
		@@ -58,6 +58,16 @@ struct serial_private {
		int line[0];
		};

		static const struct pci_device_id pci_use_msi[] = {
		{ PCI_DEVICE_SUB(PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9900,
		0xA000, 0x1000) },
		{ PCI_DEVICE_SUB(PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9912,
		0xA000, 0x1000) },
		{ PCI_DEVICE_SUB(PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9922,
		0xA000, 0x1000) },
		{ }
		};

		static int pci_default_setup(struct serial_private*,
		const struct pciserial_board, struct uart_8250_port , int);

		@@ -4155,7 +4165,22 @@ pciserial_init_ports(struct pci_dev dev, const struct pciserial_board board)
		memset(&uart, 0, sizeof(uart));
		uart.port.flags = UPF_SKIP_TEST \| UPF_BOOT_AUTOCONF \| UPF_SHARE_IRQ;
		uart.port.uartclk = board->base_baud * 16;
		uart.port.irq = get_pci_irq(dev, board);

		if (pci_match_id(pci_use_msi, dev)) {
		dev_dbg(&dev->dev, "Using MSI(-X) interrupts\n");
		pci_set_master(dev);
		rc = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_ALL_TYPES);
		} else {
		dev_dbg(&dev->dev, "Using legacy interrupts\n");
		rc = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_LEGACY);
		}
		if (rc < 0) {
		kfree(priv);
		priv = ERR_PTR(rc);
		goto err_deinit;
		}

		uart.port.irq = pci_irq_vector(dev, 0);
		uart.port.dev = &dev->dev;

		for (i = 0; i < nr_ports; i++) {

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