static int push_cxx_to_hypervisor()

in xen-acpi-processor.c [51:134]

• 69 lines of code
• 13 McCabe index (conditional complexity)

static int push_cxx_to_hypervisor(struct acpi_processor *_pr)
{
	struct xen_platform_op op = {
		.cmd			= XENPF_set_processor_pminfo,
		.interface_version	= XENPF_INTERFACE_VERSION,
		.u.set_pminfo.id	= _pr->acpi_id,
		.u.set_pminfo.type	= XEN_PM_CX,
	};
	struct xen_processor_cx *dst_cx, *dst_cx_states = NULL;
	struct acpi_processor_cx *cx;
	unsigned int i, ok;
	int ret = 0;

	dst_cx_states = kcalloc(_pr->power.count,
				sizeof(struct xen_processor_cx), GFP_KERNEL);
	if (!dst_cx_states)
		return -ENOMEM;

	for (ok = 0, i = 1; i <= _pr->power.count; i++) {
		cx = &_pr->power.states[i];
		if (!cx->valid)
			continue;

		dst_cx = &(dst_cx_states[ok++]);

		dst_cx->reg.space_id = ACPI_ADR_SPACE_SYSTEM_IO;
		if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
			dst_cx->reg.bit_width = 8;
			dst_cx->reg.bit_offset = 0;
			dst_cx->reg.access_size = 1;
		} else {
			dst_cx->reg.space_id = ACPI_ADR_SPACE_FIXED_HARDWARE;
			if (cx->entry_method == ACPI_CSTATE_FFH) {
				/* NATIVE_CSTATE_BEYOND_HALT */
				dst_cx->reg.bit_offset = 2;
				dst_cx->reg.bit_width = 1; /* VENDOR_INTEL */
			}
			dst_cx->reg.access_size = 0;
		}
		dst_cx->reg.address = cx->address;

		dst_cx->type = cx->type;
		dst_cx->latency = cx->latency;

		dst_cx->dpcnt = 0;
		set_xen_guest_handle(dst_cx->dp, NULL);
	}
	if (!ok) {
		pr_debug("No _Cx for ACPI CPU %u\n", _pr->acpi_id);
		kfree(dst_cx_states);
		return -EINVAL;
	}
	op.u.set_pminfo.power.count = ok;
	op.u.set_pminfo.power.flags.bm_control = _pr->flags.bm_control;
	op.u.set_pminfo.power.flags.bm_check = _pr->flags.bm_check;
	op.u.set_pminfo.power.flags.has_cst = _pr->flags.has_cst;
	op.u.set_pminfo.power.flags.power_setup_done =
		_pr->flags.power_setup_done;

	set_xen_guest_handle(op.u.set_pminfo.power.states, dst_cx_states);

	if (!no_hypercall)
		ret = HYPERVISOR_platform_op(&op);

	if (!ret) {
		pr_debug("ACPI CPU%u - C-states uploaded.\n", _pr->acpi_id);
		for (i = 1; i <= _pr->power.count; i++) {
			cx = &_pr->power.states[i];
			if (!cx->valid)
				continue;
			pr_debug("     C%d: %s %d uS\n",
				 cx->type, cx->desc, (u32)cx->latency);
		}
	} else if ((ret != -EINVAL) && (ret != -ENOSYS))
		/* EINVAL means the ACPI ID is incorrect - meaning the ACPI
		 * table is referencing a non-existing CPU - which can happen
		 * with broken ACPI tables. */
		pr_err("(CX): Hypervisor error (%d) for ACPI CPU%u\n",
		       ret, _pr->acpi_id);

	kfree(dst_cx_states);

	return ret;
}