From e22cf8ca6f75a6c4fccf2d6ee818bdb1205f32e6 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Tue, 6 Oct 2015 18:06:15 +0200 Subject: s390/cpumf: rework program parameter setting to detect guest samples The program parameter can be used to mark hardware samples with some token. Previously, it was used to mark guest samples only. Improve the program parameter doubleword by combining two parts, the leftmost LPP part and the rightmost PID part. Set the PID part for processes by using the task PID. To distinguish host and guest samples for the kernel (PID part is zero), the guest must always set the program paramater to a non-zero value. Use the leftmost bit in the LPP part of the program parameter to be able to detect guest kernel samples. [brueckner@linux.vnet.ibm.com]: Split __LC_CURRENT and introduced __LC_LPP. Corrected __LC_CURRENT users and adjusted assembler parts. And updated the commit message accordingly. Signed-off-by: Christian Borntraeger Signed-off-by: Hendrik Brueckner Reviewed-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/head64.S | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'arch/s390/kernel/head64.S') diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S index d7c00507568a..58b719fa8067 100644 --- a/arch/s390/kernel/head64.S +++ b/arch/s390/kernel/head64.S @@ -16,7 +16,12 @@ __HEAD ENTRY(startup_continue) - larl %r1,sched_clock_base_cc + tm __LC_STFL_FAC_LIST+6,0x80 # LPP available ? + jz 0f + xc __LC_LPP+1(7,0),__LC_LPP+1 # clear lpp and current_pid + mvi __LC_LPP,0x80 # and set LPP_MAGIC + .insn s,0xb2800000,__LC_LPP # load program parameter +0: larl %r1,sched_clock_base_cc mvc 0(8,%r1),__LC_LAST_UPDATE_CLOCK larl %r13,.LPG1 # get base lctlg %c0,%c15,.Lctl-.LPG1(%r13) # load control registers -- cgit v1.2.3