arm64: hyperv: Add panic handler

	return output.as64.low;

}

EXPORT_SYMBOL_GPL(hv_get_vpreg);

/*

 * hyperv_report_panic - report a panic to Hyper-V.  This function uses

 * the older version of the Hyper-V interface that admittedly doesn't

 * pass enough information to be useful beyond just recording the

 * occurrence of a panic. The parallel hv_kmsg_dump() uses the

 * new interface that allows reporting 4 Kbytes of data, which is much

 * more useful. Hyper-V on ARM64 always supports the newer interface, but

 * we retain support for the older version because the sysadmin is allowed

 * to disable the newer version via sysctl in case of information security

 * concerns about the more verbose version.

 */

void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die)

{

	static bool	panic_reported;

	u64		guest_id;

	/* Don't report a panic to Hyper-V if we're not going to panic */

	if (in_die && !panic_on_oops)

		return;

	/*

	 * We prefer to report panic on 'die' chain as we have proper

	 * registers to report, but if we miss it (e.g. on BUG()) we need

	 * to report it on 'panic'.

	 *

	 * Calling code in the 'die' and 'panic' paths ensures that only

	 * one CPU is running this code, so no atomicity is needed.

	 */

	if (panic_reported)

		return;

	panic_reported = true;

	guest_id = hv_get_vpreg(HV_REGISTER_GUEST_OSID);

	/*

	 * Hyper-V provides the ability to store only 5 values.

	 * Pick the passed in error value, the guest_id, the PC,

	 * and the SP.

	 */

	hv_set_vpreg(HV_REGISTER_CRASH_P0, err);

	hv_set_vpreg(HV_REGISTER_CRASH_P1, guest_id);

	hv_set_vpreg(HV_REGISTER_CRASH_P2, regs->pc);

	hv_set_vpreg(HV_REGISTER_CRASH_P3, regs->sp);

	hv_set_vpreg(HV_REGISTER_CRASH_P4, 0);

	/*

	 * Let Hyper-V know there is crash data available

	 */

	hv_set_vpreg(HV_REGISTER_CRASH_CTL, HV_CRASH_CTL_CRASH_NOTIFY);

}

EXPORT_SYMBOL_GPL(hyperv_report_panic);