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>
diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h
index 663f23e..12af453 100644
--- a/arch/s390/include/asm/lowcore.h
+++ b/arch/s390/include/asm/lowcore.h
@@ -132,7 +132,14 @@
/* 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 */
diff --git a/arch/s390/include/asm/setup.h b/arch/s390/include/asm/setup.h
index ab015a7..2353766 100644
--- a/arch/s390/include/asm/setup.h
+++ b/arch/s390/include/asm/setup.h
@@ -34,6 +34,9 @@
#define MACHINE_FLAG_VX _BITUL(18)
#define MACHINE_FLAG_CAD _BITUL(19)
+#define LPP_MAGIC _BITUL(31)
+#define LPP_PFAULT_PID_MASK _AC(0xffffffff, UL)
+
#ifndef __ASSEMBLY__
#include <asm/lowcore.h>