![Martin Schwidefsky](/assets/img/avatar_default.png)
Use the ACCESS_ONCE macro for both accesses to idle->sequence in the loops to calculate the idle time. If only one access uses the macro, the compiler is free to cache the value for the second access which can cause endless loops. Cc: stable@vger.kernel.org # 3.6+ Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
1064 lines
26 KiB
C
1064 lines
26 KiB
C
/*
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* SMP related functions
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*
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* Copyright IBM Corp. 1999, 2012
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* Author(s): Denis Joseph Barrow,
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* Martin Schwidefsky <schwidefsky@de.ibm.com>,
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* Heiko Carstens <heiko.carstens@de.ibm.com>,
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*
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* based on other smp stuff by
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* (c) 1995 Alan Cox, CymruNET Ltd <alan@cymru.net>
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* (c) 1998 Ingo Molnar
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*
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* The code outside of smp.c uses logical cpu numbers, only smp.c does
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* the translation of logical to physical cpu ids. All new code that
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* operates on physical cpu numbers needs to go into smp.c.
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*/
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#define KMSG_COMPONENT "cpu"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/workqueue.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/mm.h>
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#include <linux/err.h>
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#include <linux/spinlock.h>
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#include <linux/kernel_stat.h>
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#include <linux/delay.h>
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#include <linux/interrupt.h>
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#include <linux/irqflags.h>
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#include <linux/cpu.h>
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#include <linux/slab.h>
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#include <linux/crash_dump.h>
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#include <asm/asm-offsets.h>
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#include <asm/switch_to.h>
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#include <asm/facility.h>
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#include <asm/ipl.h>
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#include <asm/setup.h>
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#include <asm/irq.h>
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#include <asm/tlbflush.h>
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#include <asm/vtimer.h>
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#include <asm/lowcore.h>
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#include <asm/sclp.h>
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#include <asm/vdso.h>
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#include <asm/debug.h>
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#include <asm/os_info.h>
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#include <asm/sigp.h>
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#include "entry.h"
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enum {
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ec_schedule = 0,
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ec_call_function_single,
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ec_stop_cpu,
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};
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enum {
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CPU_STATE_STANDBY,
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CPU_STATE_CONFIGURED,
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};
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struct pcpu {
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struct cpu cpu;
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struct _lowcore *lowcore; /* lowcore page(s) for the cpu */
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unsigned long async_stack; /* async stack for the cpu */
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unsigned long panic_stack; /* panic stack for the cpu */
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unsigned long ec_mask; /* bit mask for ec_xxx functions */
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int state; /* physical cpu state */
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int polarization; /* physical polarization */
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u16 address; /* physical cpu address */
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};
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static u8 boot_cpu_type;
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static u16 boot_cpu_address;
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static struct pcpu pcpu_devices[NR_CPUS];
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/*
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* The smp_cpu_state_mutex must be held when changing the state or polarization
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* member of a pcpu data structure within the pcpu_devices arreay.
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*/
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DEFINE_MUTEX(smp_cpu_state_mutex);
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/*
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* Signal processor helper functions.
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*/
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static inline int __pcpu_sigp(u16 addr, u8 order, u32 parm, u32 *status)
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{
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register unsigned int reg1 asm ("1") = parm;
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int cc;
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asm volatile(
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" sigp %1,%2,0(%3)\n"
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" ipm %0\n"
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" srl %0,28\n"
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: "=d" (cc), "+d" (reg1) : "d" (addr), "a" (order) : "cc");
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if (status && cc == 1)
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*status = reg1;
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return cc;
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}
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static inline int __pcpu_sigp_relax(u16 addr, u8 order, u32 parm, u32 *status)
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{
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int cc;
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while (1) {
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cc = __pcpu_sigp(addr, order, parm, NULL);
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if (cc != SIGP_CC_BUSY)
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return cc;
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cpu_relax();
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}
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}
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static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
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{
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int cc, retry;
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for (retry = 0; ; retry++) {
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cc = __pcpu_sigp(pcpu->address, order, parm, NULL);
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if (cc != SIGP_CC_BUSY)
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break;
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if (retry >= 3)
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udelay(10);
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}
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return cc;
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}
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static inline int pcpu_stopped(struct pcpu *pcpu)
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{
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u32 uninitialized_var(status);
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if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
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0, &status) != SIGP_CC_STATUS_STORED)
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return 0;
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return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
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}
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static inline int pcpu_running(struct pcpu *pcpu)
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{
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if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING,
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0, NULL) != SIGP_CC_STATUS_STORED)
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return 1;
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/* Status stored condition code is equivalent to cpu not running. */
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return 0;
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}
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/*
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* Find struct pcpu by cpu address.
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*/
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static struct pcpu *pcpu_find_address(const struct cpumask *mask, int address)
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{
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int cpu;
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for_each_cpu(cpu, mask)
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if (pcpu_devices[cpu].address == address)
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return pcpu_devices + cpu;
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return NULL;
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}
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static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
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{
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int order;
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set_bit(ec_bit, &pcpu->ec_mask);
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order = pcpu_running(pcpu) ?
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SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL;
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pcpu_sigp_retry(pcpu, order, 0);
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}
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static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
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{
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struct _lowcore *lc;
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if (pcpu != &pcpu_devices[0]) {
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pcpu->lowcore = (struct _lowcore *)
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__get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
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pcpu->async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
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pcpu->panic_stack = __get_free_page(GFP_KERNEL);
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if (!pcpu->lowcore || !pcpu->panic_stack || !pcpu->async_stack)
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goto out;
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}
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lc = pcpu->lowcore;
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memcpy(lc, &S390_lowcore, 512);
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memset((char *) lc + 512, 0, sizeof(*lc) - 512);
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lc->async_stack = pcpu->async_stack + ASYNC_SIZE
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- STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
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lc->panic_stack = pcpu->panic_stack + PAGE_SIZE
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- STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
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lc->cpu_nr = cpu;
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#ifndef CONFIG_64BIT
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if (MACHINE_HAS_IEEE) {
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lc->extended_save_area_addr = get_zeroed_page(GFP_KERNEL);
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if (!lc->extended_save_area_addr)
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goto out;
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}
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#else
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if (vdso_alloc_per_cpu(lc))
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goto out;
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#endif
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lowcore_ptr[cpu] = lc;
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pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc);
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return 0;
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out:
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if (pcpu != &pcpu_devices[0]) {
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free_page(pcpu->panic_stack);
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free_pages(pcpu->async_stack, ASYNC_ORDER);
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free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
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}
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return -ENOMEM;
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}
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#ifdef CONFIG_HOTPLUG_CPU
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static void pcpu_free_lowcore(struct pcpu *pcpu)
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{
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pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
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lowcore_ptr[pcpu - pcpu_devices] = NULL;
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#ifndef CONFIG_64BIT
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if (MACHINE_HAS_IEEE) {
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struct _lowcore *lc = pcpu->lowcore;
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free_page((unsigned long) lc->extended_save_area_addr);
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lc->extended_save_area_addr = 0;
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}
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#else
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vdso_free_per_cpu(pcpu->lowcore);
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#endif
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if (pcpu != &pcpu_devices[0]) {
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free_page(pcpu->panic_stack);
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free_pages(pcpu->async_stack, ASYNC_ORDER);
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free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
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}
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}
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#endif /* CONFIG_HOTPLUG_CPU */
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static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
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{
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struct _lowcore *lc = pcpu->lowcore;
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atomic_inc(&init_mm.context.attach_count);
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lc->cpu_nr = cpu;
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lc->percpu_offset = __per_cpu_offset[cpu];
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lc->kernel_asce = S390_lowcore.kernel_asce;
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lc->machine_flags = S390_lowcore.machine_flags;
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lc->ftrace_func = S390_lowcore.ftrace_func;
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lc->user_timer = lc->system_timer = lc->steal_timer = 0;
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__ctl_store(lc->cregs_save_area, 0, 15);
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save_access_regs((unsigned int *) lc->access_regs_save_area);
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memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
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MAX_FACILITY_BIT/8);
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}
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static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
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{
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struct _lowcore *lc = pcpu->lowcore;
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struct thread_info *ti = task_thread_info(tsk);
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lc->kernel_stack = (unsigned long) task_stack_page(tsk)
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+ THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
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lc->thread_info = (unsigned long) task_thread_info(tsk);
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lc->current_task = (unsigned long) tsk;
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lc->user_timer = ti->user_timer;
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lc->system_timer = ti->system_timer;
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lc->steal_timer = 0;
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}
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static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
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{
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struct _lowcore *lc = pcpu->lowcore;
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lc->restart_stack = lc->kernel_stack;
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lc->restart_fn = (unsigned long) func;
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lc->restart_data = (unsigned long) data;
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lc->restart_source = -1UL;
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pcpu_sigp_retry(pcpu, SIGP_RESTART, 0);
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}
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/*
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* Call function via PSW restart on pcpu and stop the current cpu.
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*/
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static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *),
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void *data, unsigned long stack)
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{
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struct _lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
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unsigned long source_cpu = stap();
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__load_psw_mask(PSW_KERNEL_BITS);
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if (pcpu->address == source_cpu)
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func(data); /* should not return */
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/* Stop target cpu (if func returns this stops the current cpu). */
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pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
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/* Restart func on the target cpu and stop the current cpu. */
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mem_assign_absolute(lc->restart_stack, stack);
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mem_assign_absolute(lc->restart_fn, (unsigned long) func);
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mem_assign_absolute(lc->restart_data, (unsigned long) data);
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mem_assign_absolute(lc->restart_source, source_cpu);
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asm volatile(
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"0: sigp 0,%0,%2 # sigp restart to target cpu\n"
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" brc 2,0b # busy, try again\n"
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"1: sigp 0,%1,%3 # sigp stop to current cpu\n"
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" brc 2,1b # busy, try again\n"
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: : "d" (pcpu->address), "d" (source_cpu),
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"K" (SIGP_RESTART), "K" (SIGP_STOP)
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: "0", "1", "cc");
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for (;;) ;
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}
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/*
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* Call function on an online CPU.
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*/
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void smp_call_online_cpu(void (*func)(void *), void *data)
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{
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struct pcpu *pcpu;
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/* Use the current cpu if it is online. */
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pcpu = pcpu_find_address(cpu_online_mask, stap());
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if (!pcpu)
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/* Use the first online cpu. */
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pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
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pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
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}
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/*
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* Call function on the ipl CPU.
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*/
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void smp_call_ipl_cpu(void (*func)(void *), void *data)
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{
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pcpu_delegate(&pcpu_devices[0], func, data,
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pcpu_devices->panic_stack + PAGE_SIZE);
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}
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int smp_find_processor_id(u16 address)
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{
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int cpu;
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for_each_present_cpu(cpu)
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if (pcpu_devices[cpu].address == address)
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return cpu;
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return -1;
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}
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int smp_vcpu_scheduled(int cpu)
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{
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return pcpu_running(pcpu_devices + cpu);
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}
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void smp_yield(void)
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{
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if (MACHINE_HAS_DIAG44)
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asm volatile("diag 0,0,0x44");
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}
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void smp_yield_cpu(int cpu)
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{
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if (MACHINE_HAS_DIAG9C)
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asm volatile("diag %0,0,0x9c"
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: : "d" (pcpu_devices[cpu].address));
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else if (MACHINE_HAS_DIAG44)
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asm volatile("diag 0,0,0x44");
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}
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/*
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* Send cpus emergency shutdown signal. This gives the cpus the
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* opportunity to complete outstanding interrupts.
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*/
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static void smp_emergency_stop(cpumask_t *cpumask)
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{
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u64 end;
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int cpu;
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end = get_tod_clock() + (1000000UL << 12);
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for_each_cpu(cpu, cpumask) {
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struct pcpu *pcpu = pcpu_devices + cpu;
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set_bit(ec_stop_cpu, &pcpu->ec_mask);
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while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL,
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0, NULL) == SIGP_CC_BUSY &&
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get_tod_clock() < end)
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cpu_relax();
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}
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while (get_tod_clock() < end) {
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for_each_cpu(cpu, cpumask)
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if (pcpu_stopped(pcpu_devices + cpu))
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cpumask_clear_cpu(cpu, cpumask);
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if (cpumask_empty(cpumask))
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break;
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cpu_relax();
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}
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}
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/*
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* Stop all cpus but the current one.
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*/
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void smp_send_stop(void)
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{
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cpumask_t cpumask;
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int cpu;
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/* Disable all interrupts/machine checks */
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__load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
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trace_hardirqs_off();
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debug_set_critical();
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cpumask_copy(&cpumask, cpu_online_mask);
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cpumask_clear_cpu(smp_processor_id(), &cpumask);
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if (oops_in_progress)
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smp_emergency_stop(&cpumask);
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/* stop all processors */
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for_each_cpu(cpu, &cpumask) {
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struct pcpu *pcpu = pcpu_devices + cpu;
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pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
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while (!pcpu_stopped(pcpu))
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cpu_relax();
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}
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}
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/*
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* Stop the current cpu.
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*/
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void smp_stop_cpu(void)
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{
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pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
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for (;;) ;
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}
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/*
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* This is the main routine where commands issued by other
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* cpus are handled.
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*/
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static void smp_handle_ext_call(void)
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{
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unsigned long bits;
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/* handle bit signal external calls */
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bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0);
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if (test_bit(ec_stop_cpu, &bits))
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smp_stop_cpu();
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if (test_bit(ec_schedule, &bits))
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scheduler_ipi();
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if (test_bit(ec_call_function_single, &bits))
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generic_smp_call_function_single_interrupt();
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}
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static void do_ext_call_interrupt(struct ext_code ext_code,
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unsigned int param32, unsigned long param64)
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{
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inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS);
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smp_handle_ext_call();
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}
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void arch_send_call_function_ipi_mask(const struct cpumask *mask)
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{
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int cpu;
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for_each_cpu(cpu, mask)
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pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
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}
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void arch_send_call_function_single_ipi(int cpu)
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{
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pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
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}
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|
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#ifndef CONFIG_64BIT
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/*
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* this function sends a 'purge tlb' signal to another CPU.
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*/
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static void smp_ptlb_callback(void *info)
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{
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__tlb_flush_local();
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}
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void smp_ptlb_all(void)
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{
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on_each_cpu(smp_ptlb_callback, NULL, 1);
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}
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EXPORT_SYMBOL(smp_ptlb_all);
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#endif /* ! CONFIG_64BIT */
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/*
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* this function sends a 'reschedule' IPI to another CPU.
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* it goes straight through and wastes no time serializing
|
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* anything. Worst case is that we lose a reschedule ...
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*/
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void smp_send_reschedule(int cpu)
|
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{
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pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
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}
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|
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/*
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* parameter area for the set/clear control bit callbacks
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*/
|
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struct ec_creg_mask_parms {
|
|
unsigned long orval;
|
|
unsigned long andval;
|
|
int cr;
|
|
};
|
|
|
|
/*
|
|
* callback for setting/clearing control bits
|
|
*/
|
|
static void smp_ctl_bit_callback(void *info)
|
|
{
|
|
struct ec_creg_mask_parms *pp = info;
|
|
unsigned long cregs[16];
|
|
|
|
__ctl_store(cregs, 0, 15);
|
|
cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
|
|
__ctl_load(cregs, 0, 15);
|
|
}
|
|
|
|
/*
|
|
* Set a bit in a control register of all cpus
|
|
*/
|
|
void smp_ctl_set_bit(int cr, int bit)
|
|
{
|
|
struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
|
|
|
|
on_each_cpu(smp_ctl_bit_callback, &parms, 1);
|
|
}
|
|
EXPORT_SYMBOL(smp_ctl_set_bit);
|
|
|
|
/*
|
|
* Clear a bit in a control register of all cpus
|
|
*/
|
|
void smp_ctl_clear_bit(int cr, int bit)
|
|
{
|
|
struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
|
|
|
|
on_each_cpu(smp_ctl_bit_callback, &parms, 1);
|
|
}
|
|
EXPORT_SYMBOL(smp_ctl_clear_bit);
|
|
|
|
#if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_CRASH_DUMP)
|
|
|
|
static void __init smp_get_save_area(int cpu, u16 address)
|
|
{
|
|
void *lc = pcpu_devices[0].lowcore;
|
|
struct save_area *save_area;
|
|
|
|
if (is_kdump_kernel())
|
|
return;
|
|
if (!OLDMEM_BASE && (address == boot_cpu_address ||
|
|
ipl_info.type != IPL_TYPE_FCP_DUMP))
|
|
return;
|
|
save_area = dump_save_area_create(cpu);
|
|
if (!save_area)
|
|
panic("could not allocate memory for save area\n");
|
|
#ifdef CONFIG_CRASH_DUMP
|
|
if (address == boot_cpu_address) {
|
|
/* Copy the registers of the boot cpu. */
|
|
copy_oldmem_page(1, (void *) save_area, sizeof(*save_area),
|
|
SAVE_AREA_BASE - PAGE_SIZE, 0);
|
|
return;
|
|
}
|
|
#endif
|
|
/* Get the registers of a non-boot cpu. */
|
|
__pcpu_sigp_relax(address, SIGP_STOP_AND_STORE_STATUS, 0, NULL);
|
|
memcpy_real(save_area, lc + SAVE_AREA_BASE, sizeof(*save_area));
|
|
}
|
|
|
|
int smp_store_status(int cpu)
|
|
{
|
|
struct pcpu *pcpu;
|
|
|
|
pcpu = pcpu_devices + cpu;
|
|
if (__pcpu_sigp_relax(pcpu->address, SIGP_STOP_AND_STORE_STATUS,
|
|
0, NULL) != SIGP_CC_ORDER_CODE_ACCEPTED)
|
|
return -EIO;
|
|
return 0;
|
|
}
|
|
|
|
#else /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */
|
|
|
|
static inline void smp_get_save_area(int cpu, u16 address) { }
|
|
|
|
#endif /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */
|
|
|
|
void smp_cpu_set_polarization(int cpu, int val)
|
|
{
|
|
pcpu_devices[cpu].polarization = val;
|
|
}
|
|
|
|
int smp_cpu_get_polarization(int cpu)
|
|
{
|
|
return pcpu_devices[cpu].polarization;
|
|
}
|
|
|
|
static struct sclp_cpu_info *smp_get_cpu_info(void)
|
|
{
|
|
static int use_sigp_detection;
|
|
struct sclp_cpu_info *info;
|
|
int address;
|
|
|
|
info = kzalloc(sizeof(*info), GFP_KERNEL);
|
|
if (info && (use_sigp_detection || sclp_get_cpu_info(info))) {
|
|
use_sigp_detection = 1;
|
|
for (address = 0; address <= MAX_CPU_ADDRESS; address++) {
|
|
if (__pcpu_sigp_relax(address, SIGP_SENSE, 0, NULL) ==
|
|
SIGP_CC_NOT_OPERATIONAL)
|
|
continue;
|
|
info->cpu[info->configured].address = address;
|
|
info->configured++;
|
|
}
|
|
info->combined = info->configured;
|
|
}
|
|
return info;
|
|
}
|
|
|
|
static int smp_add_present_cpu(int cpu);
|
|
|
|
static int __smp_rescan_cpus(struct sclp_cpu_info *info, int sysfs_add)
|
|
{
|
|
struct pcpu *pcpu;
|
|
cpumask_t avail;
|
|
int cpu, nr, i;
|
|
|
|
nr = 0;
|
|
cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
|
|
cpu = cpumask_first(&avail);
|
|
for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) {
|
|
if (info->has_cpu_type && info->cpu[i].type != boot_cpu_type)
|
|
continue;
|
|
if (pcpu_find_address(cpu_present_mask, info->cpu[i].address))
|
|
continue;
|
|
pcpu = pcpu_devices + cpu;
|
|
pcpu->address = info->cpu[i].address;
|
|
pcpu->state = (i >= info->configured) ?
|
|
CPU_STATE_STANDBY : CPU_STATE_CONFIGURED;
|
|
smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
|
|
set_cpu_present(cpu, true);
|
|
if (sysfs_add && smp_add_present_cpu(cpu) != 0)
|
|
set_cpu_present(cpu, false);
|
|
else
|
|
nr++;
|
|
cpu = cpumask_next(cpu, &avail);
|
|
}
|
|
return nr;
|
|
}
|
|
|
|
static void __init smp_detect_cpus(void)
|
|
{
|
|
unsigned int cpu, c_cpus, s_cpus;
|
|
struct sclp_cpu_info *info;
|
|
|
|
info = smp_get_cpu_info();
|
|
if (!info)
|
|
panic("smp_detect_cpus failed to allocate memory\n");
|
|
if (info->has_cpu_type) {
|
|
for (cpu = 0; cpu < info->combined; cpu++) {
|
|
if (info->cpu[cpu].address != boot_cpu_address)
|
|
continue;
|
|
/* The boot cpu dictates the cpu type. */
|
|
boot_cpu_type = info->cpu[cpu].type;
|
|
break;
|
|
}
|
|
}
|
|
c_cpus = s_cpus = 0;
|
|
for (cpu = 0; cpu < info->combined; cpu++) {
|
|
if (info->has_cpu_type && info->cpu[cpu].type != boot_cpu_type)
|
|
continue;
|
|
if (cpu < info->configured) {
|
|
smp_get_save_area(c_cpus, info->cpu[cpu].address);
|
|
c_cpus++;
|
|
} else
|
|
s_cpus++;
|
|
}
|
|
pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
|
|
get_online_cpus();
|
|
__smp_rescan_cpus(info, 0);
|
|
put_online_cpus();
|
|
kfree(info);
|
|
}
|
|
|
|
/*
|
|
* Activate a secondary processor.
|
|
*/
|
|
static void smp_start_secondary(void *cpuvoid)
|
|
{
|
|
S390_lowcore.last_update_clock = get_tod_clock();
|
|
S390_lowcore.restart_stack = (unsigned long) restart_stack;
|
|
S390_lowcore.restart_fn = (unsigned long) do_restart;
|
|
S390_lowcore.restart_data = 0;
|
|
S390_lowcore.restart_source = -1UL;
|
|
restore_access_regs(S390_lowcore.access_regs_save_area);
|
|
__ctl_load(S390_lowcore.cregs_save_area, 0, 15);
|
|
__load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
|
|
cpu_init();
|
|
preempt_disable();
|
|
init_cpu_timer();
|
|
init_cpu_vtimer();
|
|
pfault_init();
|
|
notify_cpu_starting(smp_processor_id());
|
|
set_cpu_online(smp_processor_id(), true);
|
|
inc_irq_stat(CPU_RST);
|
|
local_irq_enable();
|
|
cpu_startup_entry(CPUHP_ONLINE);
|
|
}
|
|
|
|
/* Upping and downing of CPUs */
|
|
int __cpu_up(unsigned int cpu, struct task_struct *tidle)
|
|
{
|
|
struct pcpu *pcpu;
|
|
int rc;
|
|
|
|
pcpu = pcpu_devices + cpu;
|
|
if (pcpu->state != CPU_STATE_CONFIGURED)
|
|
return -EIO;
|
|
if (pcpu_sigp_retry(pcpu, SIGP_INITIAL_CPU_RESET, 0) !=
|
|
SIGP_CC_ORDER_CODE_ACCEPTED)
|
|
return -EIO;
|
|
|
|
rc = pcpu_alloc_lowcore(pcpu, cpu);
|
|
if (rc)
|
|
return rc;
|
|
pcpu_prepare_secondary(pcpu, cpu);
|
|
pcpu_attach_task(pcpu, tidle);
|
|
pcpu_start_fn(pcpu, smp_start_secondary, NULL);
|
|
while (!cpu_online(cpu))
|
|
cpu_relax();
|
|
return 0;
|
|
}
|
|
|
|
static int __init setup_possible_cpus(char *s)
|
|
{
|
|
int max, cpu;
|
|
|
|
if (kstrtoint(s, 0, &max) < 0)
|
|
return 0;
|
|
init_cpu_possible(cpumask_of(0));
|
|
for (cpu = 1; cpu < max && cpu < nr_cpu_ids; cpu++)
|
|
set_cpu_possible(cpu, true);
|
|
return 0;
|
|
}
|
|
early_param("possible_cpus", setup_possible_cpus);
|
|
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
|
|
int __cpu_disable(void)
|
|
{
|
|
unsigned long cregs[16];
|
|
|
|
/* Handle possible pending IPIs */
|
|
smp_handle_ext_call();
|
|
set_cpu_online(smp_processor_id(), false);
|
|
/* Disable pseudo page faults on this cpu. */
|
|
pfault_fini();
|
|
/* Disable interrupt sources via control register. */
|
|
__ctl_store(cregs, 0, 15);
|
|
cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */
|
|
cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */
|
|
cregs[14] &= ~0x1f000000UL; /* disable most machine checks */
|
|
__ctl_load(cregs, 0, 15);
|
|
return 0;
|
|
}
|
|
|
|
void __cpu_die(unsigned int cpu)
|
|
{
|
|
struct pcpu *pcpu;
|
|
|
|
/* Wait until target cpu is down */
|
|
pcpu = pcpu_devices + cpu;
|
|
while (!pcpu_stopped(pcpu))
|
|
cpu_relax();
|
|
pcpu_free_lowcore(pcpu);
|
|
atomic_dec(&init_mm.context.attach_count);
|
|
}
|
|
|
|
void __noreturn cpu_die(void)
|
|
{
|
|
idle_task_exit();
|
|
pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
|
|
for (;;) ;
|
|
}
|
|
|
|
#endif /* CONFIG_HOTPLUG_CPU */
|
|
|
|
void __init smp_prepare_cpus(unsigned int max_cpus)
|
|
{
|
|
/* request the 0x1201 emergency signal external interrupt */
|
|
if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
|
|
panic("Couldn't request external interrupt 0x1201");
|
|
/* request the 0x1202 external call external interrupt */
|
|
if (register_external_interrupt(0x1202, do_ext_call_interrupt) != 0)
|
|
panic("Couldn't request external interrupt 0x1202");
|
|
smp_detect_cpus();
|
|
}
|
|
|
|
void __init smp_prepare_boot_cpu(void)
|
|
{
|
|
struct pcpu *pcpu = pcpu_devices;
|
|
|
|
boot_cpu_address = stap();
|
|
pcpu->state = CPU_STATE_CONFIGURED;
|
|
pcpu->address = boot_cpu_address;
|
|
pcpu->lowcore = (struct _lowcore *)(unsigned long) store_prefix();
|
|
pcpu->async_stack = S390_lowcore.async_stack - ASYNC_SIZE
|
|
+ STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
|
|
pcpu->panic_stack = S390_lowcore.panic_stack - PAGE_SIZE
|
|
+ STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
|
|
S390_lowcore.percpu_offset = __per_cpu_offset[0];
|
|
smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
|
|
set_cpu_present(0, true);
|
|
set_cpu_online(0, true);
|
|
}
|
|
|
|
void __init smp_cpus_done(unsigned int max_cpus)
|
|
{
|
|
}
|
|
|
|
void __init smp_setup_processor_id(void)
|
|
{
|
|
S390_lowcore.cpu_nr = 0;
|
|
}
|
|
|
|
/*
|
|
* the frequency of the profiling timer can be changed
|
|
* by writing a multiplier value into /proc/profile.
|
|
*
|
|
* usually you want to run this on all CPUs ;)
|
|
*/
|
|
int setup_profiling_timer(unsigned int multiplier)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
static ssize_t cpu_configure_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
ssize_t count;
|
|
|
|
mutex_lock(&smp_cpu_state_mutex);
|
|
count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
|
|
mutex_unlock(&smp_cpu_state_mutex);
|
|
return count;
|
|
}
|
|
|
|
static ssize_t cpu_configure_store(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct pcpu *pcpu;
|
|
int cpu, val, rc;
|
|
char delim;
|
|
|
|
if (sscanf(buf, "%d %c", &val, &delim) != 1)
|
|
return -EINVAL;
|
|
if (val != 0 && val != 1)
|
|
return -EINVAL;
|
|
get_online_cpus();
|
|
mutex_lock(&smp_cpu_state_mutex);
|
|
rc = -EBUSY;
|
|
/* disallow configuration changes of online cpus and cpu 0 */
|
|
cpu = dev->id;
|
|
if (cpu_online(cpu) || cpu == 0)
|
|
goto out;
|
|
pcpu = pcpu_devices + cpu;
|
|
rc = 0;
|
|
switch (val) {
|
|
case 0:
|
|
if (pcpu->state != CPU_STATE_CONFIGURED)
|
|
break;
|
|
rc = sclp_cpu_deconfigure(pcpu->address);
|
|
if (rc)
|
|
break;
|
|
pcpu->state = CPU_STATE_STANDBY;
|
|
smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
|
|
topology_expect_change();
|
|
break;
|
|
case 1:
|
|
if (pcpu->state != CPU_STATE_STANDBY)
|
|
break;
|
|
rc = sclp_cpu_configure(pcpu->address);
|
|
if (rc)
|
|
break;
|
|
pcpu->state = CPU_STATE_CONFIGURED;
|
|
smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
|
|
topology_expect_change();
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
out:
|
|
mutex_unlock(&smp_cpu_state_mutex);
|
|
put_online_cpus();
|
|
return rc ? rc : count;
|
|
}
|
|
static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
|
|
#endif /* CONFIG_HOTPLUG_CPU */
|
|
|
|
static ssize_t show_cpu_address(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
|
|
}
|
|
static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
|
|
|
|
static struct attribute *cpu_common_attrs[] = {
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
&dev_attr_configure.attr,
|
|
#endif
|
|
&dev_attr_address.attr,
|
|
NULL,
|
|
};
|
|
|
|
static struct attribute_group cpu_common_attr_group = {
|
|
.attrs = cpu_common_attrs,
|
|
};
|
|
|
|
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);
|
|
}
|
|
static 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);
|
|
}
|
|
static DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL);
|
|
|
|
static struct attribute *cpu_online_attrs[] = {
|
|
&dev_attr_idle_count.attr,
|
|
&dev_attr_idle_time_us.attr,
|
|
NULL,
|
|
};
|
|
|
|
static struct attribute_group cpu_online_attr_group = {
|
|
.attrs = cpu_online_attrs,
|
|
};
|
|
|
|
static int smp_cpu_notify(struct notifier_block *self, unsigned long action,
|
|
void *hcpu)
|
|
{
|
|
unsigned int cpu = (unsigned int)(long)hcpu;
|
|
struct cpu *c = &pcpu_devices[cpu].cpu;
|
|
struct device *s = &c->dev;
|
|
int err = 0;
|
|
|
|
switch (action & ~CPU_TASKS_FROZEN) {
|
|
case CPU_ONLINE:
|
|
err = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
|
|
break;
|
|
case CPU_DEAD:
|
|
sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
|
|
break;
|
|
}
|
|
return notifier_from_errno(err);
|
|
}
|
|
|
|
static int smp_add_present_cpu(int cpu)
|
|
{
|
|
struct cpu *c = &pcpu_devices[cpu].cpu;
|
|
struct device *s = &c->dev;
|
|
int rc;
|
|
|
|
c->hotpluggable = 1;
|
|
rc = register_cpu(c, cpu);
|
|
if (rc)
|
|
goto out;
|
|
rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
|
|
if (rc)
|
|
goto out_cpu;
|
|
if (cpu_online(cpu)) {
|
|
rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
|
|
if (rc)
|
|
goto out_online;
|
|
}
|
|
rc = topology_cpu_init(c);
|
|
if (rc)
|
|
goto out_topology;
|
|
return 0;
|
|
|
|
out_topology:
|
|
if (cpu_online(cpu))
|
|
sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
|
|
out_online:
|
|
sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
|
|
out_cpu:
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
unregister_cpu(c);
|
|
#endif
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
|
|
int __ref smp_rescan_cpus(void)
|
|
{
|
|
struct sclp_cpu_info *info;
|
|
int nr;
|
|
|
|
info = smp_get_cpu_info();
|
|
if (!info)
|
|
return -ENOMEM;
|
|
get_online_cpus();
|
|
mutex_lock(&smp_cpu_state_mutex);
|
|
nr = __smp_rescan_cpus(info, 1);
|
|
mutex_unlock(&smp_cpu_state_mutex);
|
|
put_online_cpus();
|
|
kfree(info);
|
|
if (nr)
|
|
topology_schedule_update();
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t __ref rescan_store(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf,
|
|
size_t count)
|
|
{
|
|
int rc;
|
|
|
|
rc = smp_rescan_cpus();
|
|
return rc ? rc : count;
|
|
}
|
|
static DEVICE_ATTR(rescan, 0200, NULL, rescan_store);
|
|
#endif /* CONFIG_HOTPLUG_CPU */
|
|
|
|
static int __init s390_smp_init(void)
|
|
{
|
|
int cpu, rc;
|
|
|
|
hotcpu_notifier(smp_cpu_notify, 0);
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
|
|
if (rc)
|
|
return rc;
|
|
#endif
|
|
for_each_present_cpu(cpu) {
|
|
rc = smp_add_present_cpu(cpu);
|
|
if (rc)
|
|
return rc;
|
|
}
|
|
return 0;
|
|
}
|
|
subsys_initcall(s390_smp_init);
|