drivers/pci/controller/pci-versatile.c

Source file repositories/reference/linux-study-clean/drivers/pci/controller/pci-versatile.c

File Facts

System
Linux kernel
Corpus path
drivers/pci/controller/pci-versatile.c
Extension
.c
Size
4910 bytes
Lines
172
Domain
Representative Device Path
Bucket
PCIe NVMe Storage Path
Inferred role
Representative Device Path: implementation source
Status
source implementation candidate

Why This File Exists

Part of the selected hardware vertical slice: PCI discovery, driver binding, NVMe queues, block requests, DMA, interrupts, and completion.

Dependency Surface

Detected Declarations

Annotated Snippet

if (resource_type(entry->res) == IORESOURCE_MEM) {
			writel(entry->res->start >> 28, PCI_IMAP(mem));
			writel(__pa(PAGE_OFFSET) >> 28, PCI_SMAP(mem));
			mem++;
		}
	}

	/*
	 * We need to discover the PCI core first to configure itself
	 * before the main PCI probing is performed
	 */
	for (i = 0; i < 32; i++) {
		if ((readl(versatile_cfg_base[0] + (i << 11) + PCI_VENDOR_ID) == VP_PCI_DEVICE_ID) &&
		    (readl(versatile_cfg_base[0] + (i << 11) + PCI_CLASS_REVISION) == VP_PCI_CLASS_ID)) {
			myslot = i;
			break;
		}
	}
	if (myslot == -1) {
		dev_err(dev, "Cannot find PCI core!\n");
		return -EIO;
	}
	/*
	 * Do not to map Versatile FPGA PCI device into memory space
	 */
	pci_slot_ignore |= (1 << myslot);

	dev_info(dev, "PCI core found (slot %d)\n", myslot);

	writel(myslot, PCI_SELFID);
	local_pci_cfg_base = versatile_cfg_base[1] + (myslot << 11);

	val = readl(local_pci_cfg_base + PCI_COMMAND);
	val |= PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER | PCI_COMMAND_INVALIDATE;
	writel(val, local_pci_cfg_base + PCI_COMMAND);

	/*
	 * Configure the PCI inbound memory windows to be 1:1 mapped to SDRAM
	 */
	writel(__pa(PAGE_OFFSET), local_pci_cfg_base + PCI_BASE_ADDRESS_0);
	writel(__pa(PAGE_OFFSET), local_pci_cfg_base + PCI_BASE_ADDRESS_1);
	writel(__pa(PAGE_OFFSET), local_pci_cfg_base + PCI_BASE_ADDRESS_2);

	/*
	 * For many years the kernel and QEMU were symbiotically buggy
	 * in that they both assumed the same broken IRQ mapping.
	 * QEMU therefore attempts to auto-detect old broken kernels
	 * so that they still work on newer QEMU as they did on old
	 * QEMU. Since we now use the correct (ie matching-hardware)
	 * IRQ mapping we write a definitely different value to a
	 * PCI_INTERRUPT_LINE register to tell QEMU that we expect
	 * real hardware behaviour and it need not be backwards
	 * compatible for us. This write is harmless on real hardware.
	 */
	writel(0, versatile_cfg_base[0] + PCI_INTERRUPT_LINE);

	pci_add_flags(PCI_REASSIGN_ALL_BUS);

	bridge->ops = &pci_versatile_ops;

	return pci_host_probe(bridge);
}

static const struct of_device_id versatile_pci_of_match[] = {
	{ .compatible = "arm,versatile-pci", },
	{ },
};
MODULE_DEVICE_TABLE(of, versatile_pci_of_match);

static struct platform_driver versatile_pci_driver = {
	.driver = {
		.name = "versatile-pci",
		.of_match_table = versatile_pci_of_match,
		.suppress_bind_attrs = true,
	},
	.probe = versatile_pci_probe,
};
module_platform_driver(versatile_pci_driver);

MODULE_DESCRIPTION("Versatile PCI driver");

Annotation

Implementation Notes