Commit dc7637c4 authored by Nathan Lynch's avatar Nathan Lynch Committed by Michael Ellerman
Browse files

powerpc/rtas: Serialize firmware activation sequences 



Use rtas_ibm_activate_firmware_lock to prevent interleaving call
sequences of the ibm,activate-firmware RTAS function, which typically
requires multiple calls to complete the update. While the spec does
not specifically prohibit interleaved sequences, there's almost
certainly no advantage to allowing them.

Reviewed-by: default avatar"Aneesh Kumar K.V (IBM)" <aneesh.kumar@kernel.org>
Signed-off-by: default avatarNathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231212-papr-sys_rtas-vs-lockdown-v6-7-e9eafd0c8c6c@linux.ibm.com
parent adf7a019

arch/powerpc/kernel/rtas.c

+4 −0
Original line number Diff line number Diff line
@@ -1734,10 +1734,14 @@ void rtas_activate_firmware(void) 
		return;

	}



	mutex_lock(&rtas_ibm_activate_firmware_lock);



	do {

		fwrc = rtas_call(token, 0, 1, NULL);

	} while (rtas_busy_delay(fwrc));



	mutex_unlock(&rtas_ibm_activate_firmware_lock);



	if (fwrc)

		pr_err("ibm,activate-firmware failed (%i)\n", fwrc);

}