56e62a7370
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>
41 lines
840 B
C
41 lines
840 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright IBM Corp. 2004
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*
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* Author: Martin Schwidefsky <schwidefsky@de.ibm.com>
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*/
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#ifndef _S390_CPUTIME_H
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#define _S390_CPUTIME_H
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#include <linux/types.h>
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#include <asm/timex.h>
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#define CPUTIME_PER_USEC 4096ULL
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#define CPUTIME_PER_SEC (CPUTIME_PER_USEC * USEC_PER_SEC)
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/* We want to use full resolution of the CPU timer: 2**-12 micro-seconds. */
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#define cmpxchg_cputime(ptr, old, new) cmpxchg64(ptr, old, new)
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/*
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* Convert cputime to microseconds.
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*/
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static inline u64 cputime_to_usecs(const u64 cputime)
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{
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return cputime >> 12;
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}
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/*
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* Convert cputime to nanoseconds.
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*/
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#define cputime_to_nsecs(cputime) tod_to_ns(cputime)
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u64 arch_cpu_idle_time(int cpu);
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#define arch_idle_time(cpu) arch_cpu_idle_time(cpu)
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void account_idle_time_irq(void);
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#endif /* _S390_CPUTIME_H */
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