![Michael Holzheu](/assets/img/avatar_default.png)
Currently the smp_stop_cpu() function for SMP kernels enters a busy loop when "begin" is entered on the z/VM console after Linux is halted. To avoid this behavior, use the non-SMP variant of smp_stop_cpu() which stops the CPU again after "begin" is entered. As a side effect we now have consistent behavior for SMP and non-SMP Linux. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> 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_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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if (test_and_set_bit(ec_bit, &pcpu->ec_mask))
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return;
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order = pcpu_running(pcpu) ? 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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lc->spinlock_lockval = arch_spin_lockval(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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if (MACHINE_HAS_TLB_LC)
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cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask);
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cpumask_set_cpu(cpu, mm_cpumask(&init_mm));
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atomic_inc(&init_mm.context.attach_count);
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lc->cpu_nr = cpu;
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lc->spinlock_lockval = arch_spin_lockval(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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* 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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#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 {
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unsigned long orval;
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unsigned long andval;
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int cr;
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};
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|
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/*
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* callback for setting/clearing control bits
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*/
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static void smp_ctl_bit_callback(void *info)
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{
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struct ec_creg_mask_parms *pp = info;
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unsigned long cregs[16];
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__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);
|
|
|
|
#ifdef 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");
|
|
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;
|
|
}
|
|
/* 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_CRASH_DUMP */
|
|
|
|
static inline void smp_get_save_area(int cpu, u16 address) { }
|
|
|
|
#endif /* 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 unsigned int setup_possible_cpus __initdata;
|
|
|
|
static int __init _setup_possible_cpus(char *s)
|
|
{
|
|
get_option(&s, &setup_possible_cpus);
|
|
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);
|
|
cpumask_clear_cpu(cpu, mm_cpumask(&init_mm));
|
|
if (MACHINE_HAS_TLB_LC)
|
|
cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask);
|
|
}
|
|
|
|
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_fill_possible_mask(void)
|
|
{
|
|
unsigned int possible, sclp, cpu;
|
|
|
|
sclp = sclp_get_max_cpu() ?: nr_cpu_ids;
|
|
possible = setup_possible_cpus ?: nr_cpu_ids;
|
|
possible = min(possible, sclp);
|
|
for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++)
|
|
set_cpu_possible(cpu, true);
|
|
}
|
|
|
|
void __init smp_prepare_cpus(unsigned int max_cpus)
|
|
{
|
|
/* request the 0x1201 emergency signal external interrupt */
|
|
if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt))
|
|
panic("Couldn't request external interrupt 0x1201");
|
|
/* request the 0x1202 external call external interrupt */
|
|
if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt))
|
|
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;
|
|
S390_lowcore.spinlock_lockval = arch_spin_lockval(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 device *s;
|
|
struct cpu *c;
|
|
int rc;
|
|
|
|
c = kzalloc(sizeof(*c), GFP_KERNEL);
|
|
if (!c)
|
|
return -ENOMEM;
|
|
pcpu_devices[cpu].cpu = c;
|
|
s = &c->dev;
|
|
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 = 0;
|
|
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
|
|
if (rc)
|
|
return rc;
|
|
#endif
|
|
cpu_notifier_register_begin();
|
|
for_each_present_cpu(cpu) {
|
|
rc = smp_add_present_cpu(cpu);
|
|
if (rc)
|
|
goto out;
|
|
}
|
|
|
|
__hotcpu_notifier(smp_cpu_notify, 0);
|
|
|
|
out:
|
|
cpu_notifier_register_done();
|
|
return rc;
|
|
}
|
|
subsys_initcall(s390_smp_init);
|