s390: convert to generic entry

This patch converts s390 to use the generic entry infrastructure from
kernel/entry/*.

There are a few special things on s390:

- PIF_PER_TRAP is moved to TIF_PER_TRAP as the generic code doesn't
  know about our PIF flags in exit_to_user_mode_loop().

- The old code had several ways to restart syscalls:

  a) PIF_SYSCALL_RESTART, which was only set during execve to force a
     restart after upgrading a process (usually qemu-kvm) to pgste page
     table extensions.

  b) PIF_SYSCALL, which is set by do_signal() to indicate that the
     current syscall should be restarted. This is changed so that
     do_signal() now also uses PIF_SYSCALL_RESTART. Continuing to use
     PIF_SYSCALL doesn't work with the generic code, and changing it
     to PIF_SYSCALL_RESTART makes PIF_SYSCALL and PIF_SYSCALL_RESTART
     more unique.

- On s390 calling sys_sigreturn or sys_rt_sigreturn is implemented by
executing a svc instruction on the process stack which causes a fault.
While handling that fault the fault code sets PIF_SYSCALL to hand over
processing to the syscall code on exit to usermode.

The patch introduces PIF_SYSCALL_RET_SET, which is set if ptrace sets
a return value for a syscall. The s390x ptrace ABI uses r2 both for the
syscall number and return value, so ptrace cannot set the syscall number +
return value at the same time. The flag makes handling that a bit easier.
do_syscall() will just skip executing the syscall if PIF_SYSCALL_RET_SET
is set.

CONFIG_DEBUG_ASCE was removd in favour of the generic CONFIG_DEBUG_ENTRY.
CR1/7/13 will be checked both on kernel entry and exit to contain the
correct asces.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

1 files changed, 2 insertions, 17 deletions

diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index 79724d861dc9..d22bb28ef50c 100644
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -26,26 +26,14 @@ int main(void)
 	BLANK();
 	/* thread struct offsets */
 	OFFSET(__THREAD_ksp, thread_struct, ksp);
-	OFFSET(__THREAD_sysc_table,  thread_struct, sys_call_table);
-	OFFSET(__THREAD_last_break, thread_struct, last_break);
-	OFFSET(__THREAD_FPU_fpc, thread_struct, fpu.fpc);
-	OFFSET(__THREAD_FPU_regs, thread_struct, fpu.regs);
-	OFFSET(__THREAD_per_cause, thread_struct, per_event.cause);
-	OFFSET(__THREAD_per_address, thread_struct, per_event.address);
-	OFFSET(__THREAD_per_paid, thread_struct, per_event.paid);
-	OFFSET(__THREAD_trap_tdb, thread_struct, trap_tdb);
 	BLANK();
 	/* thread info offsets */
 	OFFSET(__TI_flags, task_struct, thread_info.flags);
 	BLANK();
 	/* pt_regs offsets */
-	OFFSET(__PT_ARGS, pt_regs, args);
 	OFFSET(__PT_PSW, pt_regs, psw);
 	OFFSET(__PT_GPRS, pt_regs, gprs);
 	OFFSET(__PT_ORIG_GPR2, pt_regs, orig_gpr2);
-	OFFSET(__PT_INT_CODE, pt_regs, int_code);
-	OFFSET(__PT_INT_PARM, pt_regs, int_parm);
-	OFFSET(__PT_INT_PARM_LONG, pt_regs, int_parm_long);
 	OFFSET(__PT_FLAGS, pt_regs, flags);
 	OFFSET(__PT_CR1, pt_regs, cr1);
 	DEFINE(__PT_SIZE, sizeof(struct pt_regs));
@@ -64,6 +52,7 @@ int main(void)
 	OFFSET(__CLOCK_IDLE_EXIT, s390_idle_data, clock_idle_exit);
 	OFFSET(__TIMER_IDLE_ENTER, s390_idle_data, timer_idle_enter);
 	OFFSET(__TIMER_IDLE_EXIT, s390_idle_data, timer_idle_exit);
+	OFFSET(__MT_CYCLES_ENTER, s390_idle_data, mt_cycles_enter);
 	BLANK();
 	/* hardware defined lowcore locations 0x000 - 0x1ff */
 	OFFSET(__LC_EXT_PARAMS, lowcore, ext_params);
@@ -115,13 +104,9 @@ int main(void)
 	OFFSET(__LC_CPU_FLAGS, lowcore, cpu_flags);
 	OFFSET(__LC_RETURN_PSW, lowcore, return_psw);
 	OFFSET(__LC_RETURN_MCCK_PSW, lowcore, return_mcck_psw);
-	OFFSET(__LC_SYNC_ENTER_TIMER, lowcore, sync_enter_timer);
-	OFFSET(__LC_ASYNC_ENTER_TIMER, lowcore, async_enter_timer);
+	OFFSET(__LC_SYS_ENTER_TIMER, lowcore, sys_enter_timer);
 	OFFSET(__LC_MCCK_ENTER_TIMER, lowcore, mcck_enter_timer);
 	OFFSET(__LC_EXIT_TIMER, lowcore, exit_timer);
-	OFFSET(__LC_USER_TIMER, lowcore, user_timer);
-	OFFSET(__LC_SYSTEM_TIMER, lowcore, system_timer);
-	OFFSET(__LC_STEAL_TIMER, lowcore, steal_timer);
 	OFFSET(__LC_LAST_UPDATE_TIMER, lowcore, last_update_timer);
 	OFFSET(__LC_LAST_UPDATE_CLOCK, lowcore, last_update_clock);
 	OFFSET(__LC_INT_CLOCK, lowcore, int_clock);