linux-stable/arch/s390/kernel/idle.c
Linus Torvalds bcf5470eb4 s390 updates for 6.3 merge window
- Large cleanup of the con3270/tty3270 driver. Among others this fixes:
   * Background Color Support
   * ASCII Line Character Support
   * VT100 Support
   * Geometries other than 80x24
 
 - Cleanup and improve cmpxchg() code. Also add cmpxchg_user_key() to
   uaccess functions, which will be used by KVM to access KVM guest memory
   with a specific storage key.
 
 - Add support for user space events counting to CPUMF.
 
 - Cleanup the vfio/ccw code, which also allows now to properly support 2K
   Format-2 IDALs.
 
 - Move kernel page table allocation and initialization to decompressor,
   which finally allows to enter the kernel with dynamic address translation
   enabled. This in turn allows to get rid of code with special handling in
   the kernel, which has to distinguish if DAT is on or off.
 
 - Replace kretprobe with rethook.
 
 - Various improvements to vfio/ap queue resets:
   * Use TAPQ to verify completion of a reset in progress rather than
     multiple invocations of ZAPQ.
   * Check TAPQ response codes when verifying successful completion of ZAPQ.
   * Fix erroneous handling of some error response codes.
   * Increase the maximum amount of time to wait for successful completion
     of ZAPQ.
 
 - Rework system call wrappers to get rid of alias functions, which were
   only left on s390.
 
 - Cleanup diag288_wdt watchdog driver. It has been agreed on with Guenter
   Roeck that this goes upstream via the s390 tree.
 
 - Add missing loadparm parameter handling for list-directed ECKD ipl/reipl.
 
 - Various improvements to memory detection code.
 
 - Remove arch_cpu_idle_time() since the current implementation is broken,
   and allows user space observable accounted idle times which can
   temporarily decrease.
 
 - Add Reset DAT-Protection support: (only) allow to change PTEs from RO to
   RW with a new RDP instruction. Unlike the currently used IPTE
   instruction, this does not necessarily guarantee that TLBs of all CPUs
   are synchronously flushed; and that remote CPUs can see spurious
   protection faults. The overall improvement for not requiring an all CPU
   synchronization, like it is required with IPTE, should be beneficial.
 
 - Fix KFENCE page fault reporting.
 
 - Smaller cleanups and improvement all over the place.
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Merge tag 's390-6.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Heiko Carstens:

 - Large cleanup of the con3270/tty3270 driver. Among others this fixes:
     - Background Color Support
     - ASCII Line Character Support
     - VT100 Support
     - Geometries other than 80x24

 - Cleanup and improve cmpxchg() code. Also add cmpxchg_user_key() to
   uaccess functions, which will be used by KVM to access KVM guest
   memory with a specific storage key

 - Add support for user space events counting to CPUMF

 - Cleanup the vfio/ccw code, which also allows now to properly support
   2K Format-2 IDALs

 - Move kernel page table allocation and initialization to decompressor,
   which finally allows to enter the kernel with dynamic address
   translation enabled. This in turn allows to get rid of code with
   special handling in the kernel, which has to distinguish if DAT is on
   or off

 - Replace kretprobe with rethook

 - Various improvements to vfio/ap queue resets:
     - Use TAPQ to verify completion of a reset in progress rather than
       multiple invocations of ZAPQ.
     - Check TAPQ response codes when verifying successful completion of
       ZAPQ.
     - Fix erroneous handling of some error response codes.
     - Increase the maximum amount of time to wait for successful
       completion of ZAPQ

 - Rework system call wrappers to get rid of alias functions, which were
   only left on s390

 - Cleanup diag288_wdt watchdog driver. It has been agreed on with
   Guenter Roeck that this goes upstream via the s390 tree

 - Add missing loadparm parameter handling for list-directed ECKD
   ipl/reipl

 - Various improvements to memory detection code

 - Remove arch_cpu_idle_time() since the current implementation is
   broken, and allows user space observable accounted idle times which
   can temporarily decrease

 - Add Reset DAT-Protection support: (only) allow to change PTEs from RO
   to RW with a new RDP instruction. Unlike the currently used IPTE
   instruction, this does not necessarily guarantee that TLBs of all
   CPUs are synchronously flushed; and that remote CPUs can see spurious
   protection faults. The overall improvement for not requiring an all
   CPU synchronization, like it is required with IPTE, should be
   beneficial

 - Fix KFENCE page fault reporting

 - Smaller cleanups and improvement all over the place

* tag 's390-6.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (182 commits)
  s390/irq,idle: simplify idle check
  s390/processor: add test_and_set_cpu_flag() and test_and_clear_cpu_flag()
  s390/processor: let cpu helper functions return boolean values
  s390/kfence: fix page fault reporting
  s390/zcrypt: introduce ctfm field in struct CPRBX
  s390: remove confusing comment from uapi types header file
  vfio/ccw: remove WARN_ON during shutdown
  s390/entry: remove toolchain dependent micro-optimization
  s390/mem_detect: do not truncate online memory ranges info
  s390/vx: remove __uint128_t type from __vector128 struct again
  s390/mm: add support for RDP (Reset DAT-Protection)
  s390/mm: define private VM_FAULT_* reasons from top bits
  Documentation: s390: correct spelling
  s390/ap: fix status returned by ap_qact()
  s390/ap: fix status returned by ap_aqic()
  s390: vfio-ap: tighten the NIB validity check
  Revert "s390/mem_detect: do not update output parameters on failure"
  s390/idle: remove arch_cpu_idle_time() and corresponding code
  s390/vx: use simple assignments to access __vector128 members
  s390/vx: add 64 and 128 bit members to __vector128 struct
  ...
2023-02-21 15:09:17 -08:00

94 lines
2.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Idle functions for s390.
*
* Copyright IBM Corp. 2014
*
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
*/
#include <linux/kernel.h>
#include <linux/kernel_stat.h>
#include <linux/notifier.h>
#include <linux/init.h>
#include <linux/cpu.h>
#include <trace/events/power.h>
#include <asm/cpu_mf.h>
#include <asm/cputime.h>
#include <asm/nmi.h>
#include <asm/smp.h>
#include "entry.h"
static DEFINE_PER_CPU(struct s390_idle_data, s390_idle);
void account_idle_time_irq(void)
{
struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
unsigned long idle_time;
u64 cycles_new[8];
int i;
if (smp_cpu_mtid) {
stcctm(MT_DIAG, smp_cpu_mtid, cycles_new);
for (i = 0; i < smp_cpu_mtid; i++)
this_cpu_add(mt_cycles[i], cycles_new[i] - idle->mt_cycles_enter[i]);
}
idle_time = S390_lowcore.int_clock - idle->clock_idle_enter;
S390_lowcore.steal_timer += idle->clock_idle_enter - S390_lowcore.last_update_clock;
S390_lowcore.last_update_clock = S390_lowcore.int_clock;
S390_lowcore.system_timer += S390_lowcore.last_update_timer - idle->timer_idle_enter;
S390_lowcore.last_update_timer = S390_lowcore.sys_enter_timer;
/* Account time spent with enabled wait psw loaded as idle time. */
WRITE_ONCE(idle->idle_time, READ_ONCE(idle->idle_time) + idle_time);
WRITE_ONCE(idle->idle_count, READ_ONCE(idle->idle_count) + 1);
account_idle_time(cputime_to_nsecs(idle_time));
}
void noinstr arch_cpu_idle(void)
{
struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
unsigned long psw_mask;
/* Wait for external, I/O or machine check interrupt. */
psw_mask = PSW_KERNEL_BITS | PSW_MASK_WAIT |
PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
clear_cpu_flag(CIF_NOHZ_DELAY);
/* psw_idle() returns with interrupts disabled. */
psw_idle(idle, psw_mask);
}
static ssize_t show_idle_count(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
return sysfs_emit(buf, "%lu\n", READ_ONCE(idle->idle_count));
}
DEVICE_ATTR(idle_count, 0444, show_idle_count, NULL);
static ssize_t show_idle_time(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
return sysfs_emit(buf, "%lu\n", READ_ONCE(idle->idle_time) >> 12);
}
DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL);
void arch_cpu_idle_enter(void)
{
}
void arch_cpu_idle_exit(void)
{
}
void arch_cpu_idle_dead(void)
{
cpu_die();
}