arch/loongarch/pci/pci.c

Source file repositories/reference/linux-study-clean/arch/loongarch/pci/pci.c

File Facts

System
Linux kernel
Corpus path
arch/loongarch/pci/pci.c
Extension
.c
Size
4765 bytes
Lines
185
Domain
Architecture Layer
Bucket
arch/loongarch
Inferred role
Architecture Layer: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

subsys_initcall(pcibios_init);

int pcibios_device_add(struct pci_dev *dev)
{
	int id;
	struct irq_domain *dom;

	id = pci_domain_nr(dev->bus);
	dom = irq_find_matching_fwnode(get_pch_msi_handle(id), DOMAIN_BUS_PCI_MSI);
	dev_set_msi_domain(&dev->dev, dom);

	return 0;
}

int pcibios_alloc_irq(struct pci_dev *dev)
{
	if (acpi_disabled)
		return 0;
	if (pci_dev_msi_enabled(dev))
		return 0;
	return acpi_pci_irq_enable(dev);
}

static void pci_fixup_vgadev(struct pci_dev *pdev)
{
	struct pci_dev *devp = NULL;

	while ((devp = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, devp))) {
		if (devp->vendor != PCI_VENDOR_ID_LOONGSON) {
			vga_set_default_device(devp);
			dev_info(&pdev->dev,
				"Overriding boot device as %X:%X\n",
				devp->vendor, devp->device);
		}
	}
}
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LOONGSON, PCI_DEVICE_ID_LOONGSON_DC1, pci_fixup_vgadev);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LOONGSON, PCI_DEVICE_ID_LOONGSON_DC2, pci_fixup_vgadev);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LOONGSON, PCI_DEVICE_ID_LOONGSON_DC3, pci_fixup_vgadev);

#define CRTC_NUM_MAX		2
#define CRTC_OUTPUT_ENABLE	0x100

static void loongson_gpu_fixup_dma_hang(struct pci_dev *pdev, bool on)
{
	u32 i, val, count, crtc_offset, device;
	void __iomem *crtc_reg, *base, *regbase;
	static u32 crtc_status[CRTC_NUM_MAX] = { 0 };

	base = pdev->bus->ops->map_bus(pdev->bus, pdev->devfn + 1, 0);
	device = readw(base + PCI_DEVICE_ID);

	regbase = ioremap(readq(base + PCI_BASE_ADDRESS_0) & ~0xffull, SZ_64K);
	if (!regbase) {
		pci_err(pdev, "Failed to ioremap()\n");
		return;
	}

	switch (device) {
	case PCI_DEVICE_ID_LOONGSON_DC2:
		crtc_reg = regbase + 0x1240;
		crtc_offset = 0x10;
		break;
	case PCI_DEVICE_ID_LOONGSON_DC3:
		crtc_reg = regbase;
		crtc_offset = 0x400;
		break;
	default:
		iounmap(regbase);
		return;
	}

	for (i = 0; i < CRTC_NUM_MAX; i++, crtc_reg += crtc_offset) {
		val = readl(crtc_reg);

		if (!on)
			crtc_status[i] = val;

		/* No need to fixup if the status is off at startup. */
		if (!(crtc_status[i] & CRTC_OUTPUT_ENABLE))
			continue;

		if (on)
			val |= CRTC_OUTPUT_ENABLE;
		else
			val &= ~CRTC_OUTPUT_ENABLE;

		mb();
		writel(val, crtc_reg);

Annotation

Implementation Notes