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author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-14 03:47:00 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-14 03:47:00 +0200 |
commit | 1ee07ef6b5db7235b133ee257a3adf507697e6b3 (patch) | |
tree | 9c7a00cf98462c2a70610da9d09770c835ef8fcd /arch/s390/kernel/idle.c | |
parent | 77654908ff1a58cee4886298968b5262884aff0b (diff) | |
parent | 0cccdda8d1512af4d3f6913044e8c8e58e15ef37 (diff) | |
download | blackbird-op-linux-1ee07ef6b5db7235b133ee257a3adf507697e6b3.tar.gz blackbird-op-linux-1ee07ef6b5db7235b133ee257a3adf507697e6b3.zip |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky:
"This patch set contains the main portion of the changes for 3.18 in
regard to the s390 architecture. It is a bit bigger than usual,
mainly because of a new driver and the vector extension patches.
The interesting bits are:
- Quite a bit of work on the tracing front. Uprobes is enabled and
the ftrace code is reworked to get some of the lost performance
back if CONFIG_FTRACE is enabled.
- To improve boot time with CONFIG_DEBIG_PAGEALLOC, support for the
IPTE range facility is added.
- The rwlock code is re-factored to improve writer fairness and to be
able to use the interlocked-access instructions.
- The kernel part for the support of the vector extension is added.
- The device driver to access the CD/DVD on the HMC is added, this
will hopefully come in handy to improve the installation process.
- Add support for control-unit initiated reconfiguration.
- The crypto device driver is enhanced to enable the additional AP
domains and to allow the new crypto hardware to be used.
- Bug fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (39 commits)
s390/ftrace: simplify enabling/disabling of ftrace_graph_caller
s390/ftrace: remove 31 bit ftrace support
s390/kdump: add support for vector extension
s390/disassembler: add vector instructions
s390: add support for vector extension
s390/zcrypt: Toleration of new crypto hardware
s390/idle: consolidate idle functions and definitions
s390/nohz: use a per-cpu flag for arch_needs_cpu
s390/vtime: do not reset idle data on CPU hotplug
s390/dasd: add support for control unit initiated reconfiguration
s390/dasd: fix infinite loop during format
s390/mm: make use of ipte range facility
s390/setup: correct 4-level kernel page table detection
s390/topology: call set_sched_topology early
s390/uprobes: architecture backend for uprobes
s390/uprobes: common library for kprobes and uprobes
s390/rwlock: use the interlocked-access facility 1 instructions
s390/rwlock: improve writer fairness
s390/rwlock: remove interrupt-enabling rwlock variant.
s390/mm: remove change bit override support
...
Diffstat (limited to 'arch/s390/kernel/idle.c')
-rw-r--r-- | arch/s390/kernel/idle.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/arch/s390/kernel/idle.c b/arch/s390/kernel/idle.c new file mode 100644 index 000000000000..c846aee7372f --- /dev/null +++ b/arch/s390/kernel/idle.c @@ -0,0 +1,124 @@ +/* + * 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/kprobes.h> +#include <linux/notifier.h> +#include <linux/init.h> +#include <linux/cpu.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 __kprobes enabled_wait(void) +{ + struct s390_idle_data *idle = &__get_cpu_var(s390_idle); + unsigned long long idle_time; + unsigned long psw_mask; + + trace_hardirqs_on(); + + /* Wait for external, I/O or machine check interrupt. */ + psw_mask = PSW_KERNEL_BITS | PSW_MASK_WAIT | PSW_MASK_DAT | + PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK; + clear_cpu_flag(CIF_NOHZ_DELAY); + + /* Call the assembler magic in entry.S */ + psw_idle(idle, psw_mask); + + /* Account time spent with enabled wait psw loaded as idle time. */ + idle->sequence++; + smp_wmb(); + idle_time = idle->clock_idle_exit - idle->clock_idle_enter; + idle->clock_idle_enter = idle->clock_idle_exit = 0ULL; + idle->idle_time += idle_time; + idle->idle_count++; + account_idle_time(idle_time); + smp_wmb(); + idle->sequence++; +} + +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); + unsigned long long idle_count; + unsigned int sequence; + + do { + sequence = ACCESS_ONCE(idle->sequence); + idle_count = ACCESS_ONCE(idle->idle_count); + if (ACCESS_ONCE(idle->clock_idle_enter)) + idle_count++; + } while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence)); + return sprintf(buf, "%llu\n", 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); + unsigned long long now, idle_time, idle_enter, idle_exit; + unsigned int sequence; + + do { + now = get_tod_clock(); + sequence = ACCESS_ONCE(idle->sequence); + idle_time = ACCESS_ONCE(idle->idle_time); + idle_enter = ACCESS_ONCE(idle->clock_idle_enter); + idle_exit = ACCESS_ONCE(idle->clock_idle_exit); + } while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence)); + idle_time += idle_enter ? ((idle_exit ? : now) - idle_enter) : 0; + return sprintf(buf, "%llu\n", idle_time >> 12); +} +DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL); + +cputime64_t arch_cpu_idle_time(int cpu) +{ + struct s390_idle_data *idle = &per_cpu(s390_idle, cpu); + unsigned long long now, idle_enter, idle_exit; + unsigned int sequence; + + do { + now = get_tod_clock(); + sequence = ACCESS_ONCE(idle->sequence); + idle_enter = ACCESS_ONCE(idle->clock_idle_enter); + idle_exit = ACCESS_ONCE(idle->clock_idle_exit); + } while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence)); + return idle_enter ? ((idle_exit ?: now) - idle_enter) : 0; +} + +void arch_cpu_idle_enter(void) +{ + local_mcck_disable(); +} + +void arch_cpu_idle(void) +{ + if (!test_cpu_flag(CIF_MCCK_PENDING)) + /* Halt the cpu and keep track of cpu time accounting. */ + enabled_wait(); + local_irq_enable(); +} + +void arch_cpu_idle_exit(void) +{ + local_mcck_enable(); + if (test_cpu_flag(CIF_MCCK_PENDING)) + s390_handle_mcck(); +} + +void arch_cpu_idle_dead(void) +{ + cpu_die(); +} |