![Vegard Nossum](/assets/img/avatar_default.png)
Apart from adding the helper function itself, the rest of the kernel is converted mechanically using: git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&\(.*\)->mm_count);/mmgrab\(\1\);/' git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&\(.*\)\.mm_count);/mmgrab\(\&\1\);/' This is needed for a later patch that hooks into the helper, but might be a worthwhile cleanup on its own. (Michal Hocko provided most of the kerneldoc comment.) Link: http://lkml.kernel.org/r/20161218123229.22952-1-vegard.nossum@oracle.com Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
470 lines
11 KiB
C
470 lines
11 KiB
C
/* leon_smp.c: Sparc-Leon SMP support.
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*
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* based on sun4m_smp.c
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* Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
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* Copyright (C) 2009 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
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* Copyright (C) 2009 Konrad Eisele (konrad@gaisler.com) Aeroflex Gaisler AB
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*/
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#include <asm/head.h>
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/threads.h>
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#include <linux/smp.h>
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#include <linux/interrupt.h>
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#include <linux/kernel_stat.h>
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#include <linux/of.h>
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#include <linux/init.h>
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#include <linux/spinlock.h>
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#include <linux/mm.h>
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#include <linux/swap.h>
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#include <linux/profile.h>
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#include <linux/pm.h>
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#include <linux/delay.h>
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#include <linux/gfp.h>
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#include <linux/cpu.h>
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#include <linux/clockchips.h>
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#include <asm/cacheflush.h>
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#include <asm/tlbflush.h>
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#include <asm/ptrace.h>
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#include <linux/atomic.h>
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#include <asm/irq_regs.h>
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#include <asm/traps.h>
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#include <asm/delay.h>
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#include <asm/irq.h>
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#include <asm/page.h>
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#include <asm/pgalloc.h>
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#include <asm/pgtable.h>
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#include <asm/oplib.h>
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#include <asm/cpudata.h>
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#include <asm/asi.h>
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#include <asm/leon.h>
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#include <asm/leon_amba.h>
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#include <asm/timer.h>
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#include "kernel.h"
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#include "irq.h"
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extern ctxd_t *srmmu_ctx_table_phys;
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static int smp_processors_ready;
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extern volatile unsigned long cpu_callin_map[NR_CPUS];
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extern cpumask_t smp_commenced_mask;
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void leon_configure_cache_smp(void);
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static void leon_ipi_init(void);
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/* IRQ number of LEON IPIs */
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int leon_ipi_irq = LEON3_IRQ_IPI_DEFAULT;
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static inline unsigned long do_swap(volatile unsigned long *ptr,
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unsigned long val)
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{
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__asm__ __volatile__("swapa [%2] %3, %0\n\t" : "=&r"(val)
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: "0"(val), "r"(ptr), "i"(ASI_LEON_DCACHE_MISS)
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: "memory");
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return val;
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}
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void leon_cpu_pre_starting(void *arg)
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{
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leon_configure_cache_smp();
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}
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void leon_cpu_pre_online(void *arg)
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{
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int cpuid = hard_smp_processor_id();
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/* Allow master to continue. The master will then give us the
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* go-ahead by setting the smp_commenced_mask and will wait without
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* timeouts until our setup is completed fully (signified by
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* our bit being set in the cpu_online_mask).
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*/
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do_swap(&cpu_callin_map[cpuid], 1);
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local_ops->cache_all();
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local_ops->tlb_all();
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/* Fix idle thread fields. */
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__asm__ __volatile__("ld [%0], %%g6\n\t" : : "r"(¤t_set[cpuid])
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: "memory" /* paranoid */);
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/* Attach to the address space of init_task. */
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mmgrab(&init_mm);
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current->active_mm = &init_mm;
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while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
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mb();
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}
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/*
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* Cycle through the processors asking the PROM to start each one.
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*/
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extern struct linux_prom_registers smp_penguin_ctable;
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void leon_configure_cache_smp(void)
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{
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unsigned long cfg = sparc_leon3_get_dcachecfg();
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int me = smp_processor_id();
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if (ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg) > 4) {
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printk(KERN_INFO "Note: SMP with snooping only works on 4k cache, found %dk(0x%x) on cpu %d, disabling caches\n",
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(unsigned int)ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg),
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(unsigned int)cfg, (unsigned int)me);
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sparc_leon3_disable_cache();
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} else {
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if (cfg & ASI_LEON3_SYSCTRL_CFG_SNOOPING) {
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sparc_leon3_enable_snooping();
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} else {
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printk(KERN_INFO "Note: You have to enable snooping in the vhdl model cpu %d, disabling caches\n",
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me);
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sparc_leon3_disable_cache();
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}
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}
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local_ops->cache_all();
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local_ops->tlb_all();
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}
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static void leon_smp_setbroadcast(unsigned int mask)
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{
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int broadcast =
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((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
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LEON3_IRQMPSTATUS_BROADCAST) & 1);
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if (!broadcast) {
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prom_printf("######## !!!! The irqmp-ctrl must have broadcast enabled, smp wont work !!!!! ####### nr cpus: %d\n",
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leon_smp_nrcpus());
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if (leon_smp_nrcpus() > 1) {
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BUG();
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} else {
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prom_printf("continue anyway\n");
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return;
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}
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}
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LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpbroadcast), mask);
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}
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int leon_smp_nrcpus(void)
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{
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int nrcpu =
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((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
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LEON3_IRQMPSTATUS_CPUNR) & 0xf) + 1;
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return nrcpu;
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}
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void __init leon_boot_cpus(void)
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{
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int nrcpu = leon_smp_nrcpus();
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int me = smp_processor_id();
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/* Setup IPI */
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leon_ipi_init();
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printk(KERN_INFO "%d:(%d:%d) cpus mpirq at 0x%x\n", (unsigned int)me,
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(unsigned int)nrcpu, (unsigned int)NR_CPUS,
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(unsigned int)&(leon3_irqctrl_regs->mpstatus));
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leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, me);
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leon_enable_irq_cpu(LEON3_IRQ_TICKER, me);
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leon_enable_irq_cpu(leon_ipi_irq, me);
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leon_smp_setbroadcast(1 << LEON3_IRQ_TICKER);
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leon_configure_cache_smp();
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local_ops->cache_all();
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}
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int leon_boot_one_cpu(int i, struct task_struct *idle)
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{
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int timeout;
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current_set[i] = task_thread_info(idle);
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/* See trampoline.S:leon_smp_cpu_startup for details...
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* Initialize the contexts table
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* Since the call to prom_startcpu() trashes the structure,
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* we need to re-initialize it for each cpu
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*/
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smp_penguin_ctable.which_io = 0;
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smp_penguin_ctable.phys_addr = (unsigned int)srmmu_ctx_table_phys;
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smp_penguin_ctable.reg_size = 0;
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/* whirrr, whirrr, whirrrrrrrrr... */
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printk(KERN_INFO "Starting CPU %d : (irqmp: 0x%x)\n", (unsigned int)i,
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(unsigned int)&leon3_irqctrl_regs->mpstatus);
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local_ops->cache_all();
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/* Make sure all IRQs are of from the start for this new CPU */
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LEON_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[i], 0);
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/* Wake one CPU */
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LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpstatus), 1 << i);
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/* wheee... it's going... */
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for (timeout = 0; timeout < 10000; timeout++) {
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if (cpu_callin_map[i])
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break;
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udelay(200);
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}
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printk(KERN_INFO "Started CPU %d\n", (unsigned int)i);
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if (!(cpu_callin_map[i])) {
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printk(KERN_ERR "Processor %d is stuck.\n", i);
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return -ENODEV;
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} else {
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leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, i);
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leon_enable_irq_cpu(LEON3_IRQ_TICKER, i);
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leon_enable_irq_cpu(leon_ipi_irq, i);
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}
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local_ops->cache_all();
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return 0;
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}
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void __init leon_smp_done(void)
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{
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int i, first;
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int *prev;
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/* setup cpu list for irq rotation */
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first = 0;
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prev = &first;
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for (i = 0; i < NR_CPUS; i++) {
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if (cpu_online(i)) {
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*prev = i;
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prev = &cpu_data(i).next;
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}
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}
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*prev = first;
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local_ops->cache_all();
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/* Free unneeded trap tables */
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if (!cpu_present(1)) {
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free_reserved_page(virt_to_page(&trapbase_cpu1));
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}
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if (!cpu_present(2)) {
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free_reserved_page(virt_to_page(&trapbase_cpu2));
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}
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if (!cpu_present(3)) {
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free_reserved_page(virt_to_page(&trapbase_cpu3));
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}
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/* Ok, they are spinning and ready to go. */
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smp_processors_ready = 1;
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}
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struct leon_ipi_work {
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int single;
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int msk;
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int resched;
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};
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static DEFINE_PER_CPU_SHARED_ALIGNED(struct leon_ipi_work, leon_ipi_work);
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/* Initialize IPIs on the LEON, in order to save IRQ resources only one IRQ
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* is used for all three types of IPIs.
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*/
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static void __init leon_ipi_init(void)
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{
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int cpu, len;
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struct leon_ipi_work *work;
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struct property *pp;
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struct device_node *rootnp;
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struct tt_entry *trap_table;
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unsigned long flags;
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/* Find IPI IRQ or stick with default value */
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rootnp = of_find_node_by_path("/ambapp0");
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if (rootnp) {
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pp = of_find_property(rootnp, "ipi_num", &len);
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if (pp && (*(int *)pp->value))
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leon_ipi_irq = *(int *)pp->value;
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}
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printk(KERN_INFO "leon: SMP IPIs at IRQ %d\n", leon_ipi_irq);
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/* Adjust so that we jump directly to smpleon_ipi */
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local_irq_save(flags);
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trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (leon_ipi_irq - 1)];
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trap_table->inst_three += smpleon_ipi - real_irq_entry;
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local_ops->cache_all();
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local_irq_restore(flags);
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for_each_possible_cpu(cpu) {
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work = &per_cpu(leon_ipi_work, cpu);
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work->single = work->msk = work->resched = 0;
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}
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}
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static void leon_send_ipi(int cpu, int level)
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{
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unsigned long mask;
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mask = leon_get_irqmask(level);
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LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->force[cpu], mask);
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}
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static void leon_ipi_single(int cpu)
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{
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struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
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/* Mark work */
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work->single = 1;
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/* Generate IRQ on the CPU */
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leon_send_ipi(cpu, leon_ipi_irq);
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}
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static void leon_ipi_mask_one(int cpu)
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{
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struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
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/* Mark work */
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work->msk = 1;
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/* Generate IRQ on the CPU */
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leon_send_ipi(cpu, leon_ipi_irq);
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}
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static void leon_ipi_resched(int cpu)
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{
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struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
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/* Mark work */
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work->resched = 1;
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/* Generate IRQ on the CPU (any IRQ will cause resched) */
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leon_send_ipi(cpu, leon_ipi_irq);
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}
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void leonsmp_ipi_interrupt(void)
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{
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struct leon_ipi_work *work = this_cpu_ptr(&leon_ipi_work);
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if (work->single) {
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work->single = 0;
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smp_call_function_single_interrupt();
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}
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if (work->msk) {
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work->msk = 0;
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smp_call_function_interrupt();
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}
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if (work->resched) {
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work->resched = 0;
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smp_resched_interrupt();
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}
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}
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static struct smp_funcall {
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smpfunc_t func;
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unsigned long arg1;
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unsigned long arg2;
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unsigned long arg3;
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unsigned long arg4;
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unsigned long arg5;
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unsigned long processors_in[NR_CPUS]; /* Set when ipi entered. */
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unsigned long processors_out[NR_CPUS]; /* Set when ipi exited. */
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} ccall_info __attribute__((aligned(8)));
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static DEFINE_SPINLOCK(cross_call_lock);
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/* Cross calls must be serialized, at least currently. */
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static void leon_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
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unsigned long arg2, unsigned long arg3,
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unsigned long arg4)
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{
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if (smp_processors_ready) {
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register int high = NR_CPUS - 1;
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unsigned long flags;
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spin_lock_irqsave(&cross_call_lock, flags);
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{
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/* If you make changes here, make sure gcc generates proper code... */
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register smpfunc_t f asm("i0") = func;
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register unsigned long a1 asm("i1") = arg1;
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register unsigned long a2 asm("i2") = arg2;
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register unsigned long a3 asm("i3") = arg3;
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register unsigned long a4 asm("i4") = arg4;
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register unsigned long a5 asm("i5") = 0;
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__asm__ __volatile__("std %0, [%6]\n\t"
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"std %2, [%6 + 8]\n\t"
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"std %4, [%6 + 16]\n\t" : :
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"r"(f), "r"(a1), "r"(a2), "r"(a3),
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"r"(a4), "r"(a5),
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"r"(&ccall_info.func));
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}
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/* Init receive/complete mapping, plus fire the IPI's off. */
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{
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register int i;
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cpumask_clear_cpu(smp_processor_id(), &mask);
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cpumask_and(&mask, cpu_online_mask, &mask);
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for (i = 0; i <= high; i++) {
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if (cpumask_test_cpu(i, &mask)) {
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ccall_info.processors_in[i] = 0;
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ccall_info.processors_out[i] = 0;
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leon_send_ipi(i, LEON3_IRQ_CROSS_CALL);
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}
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}
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}
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{
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register int i;
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i = 0;
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do {
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if (!cpumask_test_cpu(i, &mask))
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continue;
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while (!ccall_info.processors_in[i])
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barrier();
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} while (++i <= high);
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i = 0;
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do {
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if (!cpumask_test_cpu(i, &mask))
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continue;
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while (!ccall_info.processors_out[i])
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barrier();
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} while (++i <= high);
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}
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spin_unlock_irqrestore(&cross_call_lock, flags);
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}
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}
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/* Running cross calls. */
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void leon_cross_call_irq(void)
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{
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int i = smp_processor_id();
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ccall_info.processors_in[i] = 1;
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ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
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ccall_info.arg4, ccall_info.arg5);
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ccall_info.processors_out[i] = 1;
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}
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static const struct sparc32_ipi_ops leon_ipi_ops = {
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.cross_call = leon_cross_call,
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.resched = leon_ipi_resched,
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.single = leon_ipi_single,
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.mask_one = leon_ipi_mask_one,
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};
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void __init leon_init_smp(void)
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{
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/* Patch ipi15 trap table */
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t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_leon - linux_trap_ipi15_sun4m);
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sparc32_ipi_ops = &leon_ipi_ops;
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}
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