Commit e22cf8ca authored by Christian Borntraeger's avatar Christian Borntraeger Committed by Martin Schwidefsky
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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: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 6a62b485

arch/s390/include/asm/lowcore.h

+8 −1
Original line number Diff line number Diff line
@@ -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 */

arch/s390/include/asm/setup.h

+3 −0
Original line number Diff line number Diff line
@@ -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>

arch/s390/kernel/asm-offsets.c

+1 −0
Original line number Diff line number Diff line
@@ -163,6 +163,7 @@ int main(void) 
	OFFSET(__LC_RESTART_DATA, _lowcore, restart_data);

	OFFSET(__LC_RESTART_SOURCE, _lowcore, restart_source);

	OFFSET(__LC_USER_ASCE, _lowcore, user_asce);

	OFFSET(__LC_LPP, _lowcore, lpp);

	OFFSET(__LC_CURRENT_PID, _lowcore, current_pid);

	OFFSET(__LC_PERCPU_OFFSET, _lowcore, percpu_offset);

	OFFSET(__LC_VDSO_PER_CPU, _lowcore, vdso_per_cpu_data);

arch/s390/kernel/entry.S

+12 −16
Original line number Diff line number Diff line
@@ -187,8 +187,11 @@ ENTRY(__switch_to) 
	stg	%r15,__LC_KERNEL_STACK		# store end of kernel stack

	lg	%r15,__THREAD_ksp(%r1)		# load kernel stack of next

	lctl	%c4,%c4,__TASK_pid(%r3)		# load pid to control reg. 4

	mvc	__LC_CURRENT_PID+4(4,%r0),__TASK_pid(%r3) # store pid of next

	mvc	__LC_CURRENT_PID(4,%r0),__TASK_pid(%r3) # store pid of next

	lmg	%r6,%r15,__SF_GPRS(%r15)	# load gprs of next task

	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_LPP

	bzr	%r14

	.insn	s,0xb2800000,__LC_LPP		# set program parameter

	br	%r14



.L__critical_start:
@@ -203,7 +206,7 @@ ENTRY(sie64a) 
	stmg	%r6,%r14,__SF_GPRS(%r15)	# save kernel registers

	stg	%r2,__SF_EMPTY(%r15)		# save control block pointer

	stg	%r3,__SF_EMPTY+8(%r15)		# save guest register save area

	xc	__SF_EMPTY+16(16,%r15),__SF_EMPTY+16(%r15) # host id & reason

	xc	__SF_EMPTY+16(8,%r15),__SF_EMPTY+16(%r15) # reason code = 0

	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU		# load guest fp/vx registers ?

	jno	.Lsie_load_guest_gprs

	brasl	%r14,load_fpu_regs		# load guest fp/vx regs
@@ -220,14 +223,7 @@ ENTRY(sie64a) 
	jnz	.Lsie_skip

	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU

	jo	.Lsie_skip			# exit if fp/vx regs changed

	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_LPP

	jz	.Lsie_enter

	.insn	s,0xb2800000,__LC_CURRENT_PID	# set guest id to pid

.Lsie_enter:

	sie	0(%r14)

	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_LPP

	jz	.Lsie_skip

	.insn	s,0xb2800000,__SF_EMPTY+16(%r15)# set host id

.Lsie_skip:

	ni	__SIE_PROG0C+3(%r14),0xfe	# no longer in SIE

	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
@@ -244,11 +240,11 @@ sie_exit: 
	lg	%r14,__SF_EMPTY+8(%r15)		# load guest register save area

	stmg	%r0,%r13,0(%r14)		# save guest gprs 0-13

	lmg	%r6,%r14,__SF_GPRS(%r15)	# restore kernel registers

	lg	%r2,__SF_EMPTY+24(%r15)		# return exit reason code

	lg	%r2,__SF_EMPTY+16(%r15)		# return exit reason code

	br	%r14

.Lsie_fault:

	lghi	%r14,-EFAULT

	stg	%r14,__SF_EMPTY+24(%r15)	# set exit reason code

	stg	%r14,__SF_EMPTY+16(%r15)	# set exit reason code

	j	sie_exit



	EX_TABLE(.Lrewind_pad,.Lsie_fault)
@@ -938,7 +934,10 @@ ENTRY(mcck_int_handler) 
# PSW restart interrupt handler

#

ENTRY(restart_int_handler)

	stg	%r15,__LC_SAVE_AREA_RESTART

	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_LPP

	jz	0f

	.insn	s,0xb2800000,__LC_LPP

0:	stg	%r15,__LC_SAVE_AREA_RESTART

	lg	%r15,__LC_RESTART_STACK

	aghi	%r15,-__PT_SIZE			# create pt_regs on stack

	xc	0(__PT_SIZE,%r15),0(%r15)
@@ -1042,10 +1041,7 @@ cleanup_critical: 


.Lcleanup_sie:

	lg	%r9,__SF_EMPTY(%r15)		# get control block pointer

	TSTMSK	__LC_MACHINE_FLAGS,MACHINE_FLAG_LPP

	jz	0f

	.insn	s,0xb2800000,__SF_EMPTY+16(%r15)# set host id

0:	ni	__SIE_PROG0C+3(%r9),0xfe	# no longer in SIE

	ni	__SIE_PROG0C+3(%r9),0xfe	# no longer in SIE

	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce

	larl	%r9,sie_exit			# skip forward to sie_exit

	br	%r14

arch/s390/kernel/head64.S

+6 −1
Original line number Diff line number Diff line
@@ -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

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