path: root/arch/s390/kernel/smp.c
diff options
authorChristian Borntraeger <borntraeger@de.ibm.com>2015-10-06 18:06:15 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2015-10-14 14:32:12 +0200
commite22cf8ca6f75a6c4fccf2d6ee818bdb1205f32e6 (patch)
tree12ed8edf751776df56b758ba1347b991dbe2afb7 /arch/s390/kernel/smp.c
parent6a62b485eacaf4db26923bf9442073320fc7199a (diff)
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 <borntraeger@de.ibm.com> Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/smp.c')
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index dbd40d448294..9062df575afe 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -262,6 +262,8 @@ static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
+ THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
lc->thread_info = (unsigned long) task_thread_info(tsk);
lc->current_task = (unsigned long) tsk;
+ lc->lpp = LPP_MAGIC;
+ lc->current_pid = tsk->pid;
lc->user_timer = ti->user_timer;
lc->system_timer = ti->system_timer;
lc->steal_timer = 0;