static void quirk_cypress()

in kernel/pci.c [70:105]

• 24 lines of code
• 7 McCabe index (conditional complexity)

static void quirk_cypress(struct pci_dev *dev)
{
	/* The Notorious Cy82C693 chip.  */

	/* The generic legacy mode IDE fixup in drivers/pci/probe.c
	   doesn't work correctly with the Cypress IDE controller as
	   it has non-standard register layout.  Fix that.  */
	if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE) {
		dev->resource[2].start = dev->resource[3].start = 0;
		dev->resource[2].end = dev->resource[3].end = 0;
		dev->resource[2].flags = dev->resource[3].flags = 0;
		if (PCI_FUNC(dev->devfn) == 2) {
			dev->resource[0].start = 0x170;
			dev->resource[0].end = 0x177;
			dev->resource[1].start = 0x376;
			dev->resource[1].end = 0x376;
		}
	}

	/* The Cypress bridge responds on the PCI bus in the address range
	   0xffff0000-0xffffffff (conventional x86 BIOS ROM).  There is no
	   way to turn this off.  The bridge also supports several extended
	   BIOS ranges (disabled after power-up), and some consoles do turn
	   them on.  So if we use a large direct-map window, or a large SG
	   window, we must avoid the entire 0xfff00000-0xffffffff region.  */
	if (dev->class >> 8 == PCI_CLASS_BRIDGE_ISA) {
		if (__direct_map_base + __direct_map_size >= 0xfff00000UL)
			__direct_map_size = 0xfff00000UL - __direct_map_base;
		else {
			struct pci_controller *hose = dev->sysdata;
			struct pci_iommu_arena *pci = hose->sg_pci;
			if (pci && pci->dma_base + pci->size >= 0xfff00000UL)
				pci->size = 0xfff00000UL - pci->dma_base;
		}
	}
}