static int __init init_iommu_from_acpi()

in amd/init.c [1177:1443]

• 203 lines of code
• 27 McCabe index (conditional complexity)

static int __init init_iommu_from_acpi(struct amd_iommu *iommu,
					struct ivhd_header *h)
{
	u8 *p = (u8 *)h;
	u8 *end = p, flags = 0;
	u16 devid = 0, devid_start = 0, devid_to = 0;
	u32 dev_i, ext_flags = 0;
	bool alias = false;
	struct ivhd_entry *e;
	u32 ivhd_size;
	int ret;


	ret = add_early_maps();
	if (ret)
		return ret;

	amd_iommu_apply_ivrs_quirks();

	/*
	 * First save the recommended feature enable bits from ACPI
	 */
	iommu->acpi_flags = h->flags;

	/*
	 * Done. Now parse the device entries
	 */
	ivhd_size = get_ivhd_header_size(h);
	if (!ivhd_size) {
		pr_err("Unsupported IVHD type %#x\n", h->type);
		return -EINVAL;
	}

	p += ivhd_size;

	end += h->length;


	while (p < end) {
		e = (struct ivhd_entry *)p;
		switch (e->type) {
		case IVHD_DEV_ALL:

			DUMP_printk("  DEV_ALL\t\t\tflags: %02x\n", e->flags);

			for (dev_i = 0; dev_i <= amd_iommu_last_bdf; ++dev_i)
				set_dev_entry_from_acpi(iommu, dev_i, e->flags, 0);
			break;
		case IVHD_DEV_SELECT:

			DUMP_printk("  DEV_SELECT\t\t\t devid: %02x:%02x.%x "
				    "flags: %02x\n",
				    PCI_BUS_NUM(e->devid),
				    PCI_SLOT(e->devid),
				    PCI_FUNC(e->devid),
				    e->flags);

			devid = e->devid;
			set_dev_entry_from_acpi(iommu, devid, e->flags, 0);
			break;
		case IVHD_DEV_SELECT_RANGE_START:

			DUMP_printk("  DEV_SELECT_RANGE_START\t "
				    "devid: %02x:%02x.%x flags: %02x\n",
				    PCI_BUS_NUM(e->devid),
				    PCI_SLOT(e->devid),
				    PCI_FUNC(e->devid),
				    e->flags);

			devid_start = e->devid;
			flags = e->flags;
			ext_flags = 0;
			alias = false;
			break;
		case IVHD_DEV_ALIAS:

			DUMP_printk("  DEV_ALIAS\t\t\t devid: %02x:%02x.%x "
				    "flags: %02x devid_to: %02x:%02x.%x\n",
				    PCI_BUS_NUM(e->devid),
				    PCI_SLOT(e->devid),
				    PCI_FUNC(e->devid),
				    e->flags,
				    PCI_BUS_NUM(e->ext >> 8),
				    PCI_SLOT(e->ext >> 8),
				    PCI_FUNC(e->ext >> 8));

			devid = e->devid;
			devid_to = e->ext >> 8;
			set_dev_entry_from_acpi(iommu, devid   , e->flags, 0);
			set_dev_entry_from_acpi(iommu, devid_to, e->flags, 0);
			amd_iommu_alias_table[devid] = devid_to;
			break;
		case IVHD_DEV_ALIAS_RANGE:

			DUMP_printk("  DEV_ALIAS_RANGE\t\t "
				    "devid: %02x:%02x.%x flags: %02x "
				    "devid_to: %02x:%02x.%x\n",
				    PCI_BUS_NUM(e->devid),
				    PCI_SLOT(e->devid),
				    PCI_FUNC(e->devid),
				    e->flags,
				    PCI_BUS_NUM(e->ext >> 8),
				    PCI_SLOT(e->ext >> 8),
				    PCI_FUNC(e->ext >> 8));

			devid_start = e->devid;
			flags = e->flags;
			devid_to = e->ext >> 8;
			ext_flags = 0;
			alias = true;
			break;
		case IVHD_DEV_EXT_SELECT:

			DUMP_printk("  DEV_EXT_SELECT\t\t devid: %02x:%02x.%x "
				    "flags: %02x ext: %08x\n",
				    PCI_BUS_NUM(e->devid),
				    PCI_SLOT(e->devid),
				    PCI_FUNC(e->devid),
				    e->flags, e->ext);

			devid = e->devid;
			set_dev_entry_from_acpi(iommu, devid, e->flags,
						e->ext);
			break;
		case IVHD_DEV_EXT_SELECT_RANGE:

			DUMP_printk("  DEV_EXT_SELECT_RANGE\t devid: "
				    "%02x:%02x.%x flags: %02x ext: %08x\n",
				    PCI_BUS_NUM(e->devid),
				    PCI_SLOT(e->devid),
				    PCI_FUNC(e->devid),
				    e->flags, e->ext);

			devid_start = e->devid;
			flags = e->flags;
			ext_flags = e->ext;
			alias = false;
			break;
		case IVHD_DEV_RANGE_END:

			DUMP_printk("  DEV_RANGE_END\t\t devid: %02x:%02x.%x\n",
				    PCI_BUS_NUM(e->devid),
				    PCI_SLOT(e->devid),
				    PCI_FUNC(e->devid));

			devid = e->devid;
			for (dev_i = devid_start; dev_i <= devid; ++dev_i) {
				if (alias) {
					amd_iommu_alias_table[dev_i] = devid_to;
					set_dev_entry_from_acpi(iommu,
						devid_to, flags, ext_flags);
				}
				set_dev_entry_from_acpi(iommu, dev_i,
							flags, ext_flags);
			}
			break;
		case IVHD_DEV_SPECIAL: {
			u8 handle, type;
			const char *var;
			u16 devid;
			int ret;

			handle = e->ext & 0xff;
			devid  = (e->ext >>  8) & 0xffff;
			type   = (e->ext >> 24) & 0xff;

			if (type == IVHD_SPECIAL_IOAPIC)
				var = "IOAPIC";
			else if (type == IVHD_SPECIAL_HPET)
				var = "HPET";
			else
				var = "UNKNOWN";

			DUMP_printk("  DEV_SPECIAL(%s[%d])\t\tdevid: %02x:%02x.%x\n",
				    var, (int)handle,
				    PCI_BUS_NUM(devid),
				    PCI_SLOT(devid),
				    PCI_FUNC(devid));

			ret = add_special_device(type, handle, &devid, false);
			if (ret)
				return ret;

			/*
			 * add_special_device might update the devid in case a
			 * command-line override is present. So call
			 * set_dev_entry_from_acpi after add_special_device.
			 */
			set_dev_entry_from_acpi(iommu, devid, e->flags, 0);

			break;
		}
		case IVHD_DEV_ACPI_HID: {
			u16 devid;
			u8 hid[ACPIHID_HID_LEN];
			u8 uid[ACPIHID_UID_LEN];
			int ret;

			if (h->type != 0x40) {
				pr_err(FW_BUG "Invalid IVHD device type %#x\n",
				       e->type);
				break;
			}

			BUILD_BUG_ON(sizeof(e->ext_hid) != ACPIHID_HID_LEN - 1);
			memcpy(hid, &e->ext_hid, ACPIHID_HID_LEN - 1);
			hid[ACPIHID_HID_LEN - 1] = '\0';

			if (!(*hid)) {
				pr_err(FW_BUG "Invalid HID.\n");
				break;
			}

			uid[0] = '\0';
			switch (e->uidf) {
			case UID_NOT_PRESENT:

				if (e->uidl != 0)
					pr_warn(FW_BUG "Invalid UID length.\n");

				break;
			case UID_IS_INTEGER:

				sprintf(uid, "%d", e->uid);

				break;
			case UID_IS_CHARACTER:

				memcpy(uid, &e->uid, e->uidl);
				uid[e->uidl] = '\0';

				break;
			default:
				break;
			}

			devid = e->devid;
			DUMP_printk("  DEV_ACPI_HID(%s[%s])\t\tdevid: %02x:%02x.%x\n",
				    hid, uid,
				    PCI_BUS_NUM(devid),
				    PCI_SLOT(devid),
				    PCI_FUNC(devid));

			flags = e->flags;

			ret = add_acpi_hid_device(hid, uid, &devid, false);
			if (ret)
				return ret;

			/*
			 * add_special_device might update the devid in case a
			 * command-line override is present. So call
			 * set_dev_entry_from_acpi after add_special_device.
			 */
			set_dev_entry_from_acpi(iommu, devid, e->flags, 0);

			break;
		}
		default:
			break;
		}

		p += ivhd_entry_length(p);
	}

	return 0;
}