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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/include/asm/lowcore.h
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/include/asm/lowcore.h')
-rw-r--r--arch/s390/include/asm/lowcore.h9
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h
index 663f23e37460..12af453c3c19 100644
--- a/arch/s390/include/asm/lowcore.h
+++ b/arch/s390/include/asm/lowcore.h
@@ -132,7 +132,14 @@ struct _lowcore {
/* Address space pointer. */
__u64 kernel_asce; /* 0x0358 */
__u64 user_asce; /* 0x0360 */
- __u64 current_pid; /* 0x0368 */
+
+ /*
+ * The lpp and current_pid fields form a
+ * 64-bit value that is set as program
+ * parameter with the LPP instruction.
+ */
+ __u32 lpp; /* 0x0368 */
+ __u32 current_pid; /* 0x036c */
/* SMP info area */
__u32 cpu_nr; /* 0x0370 */