/*
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version 2
   * of the License, or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
   *
   * Copyright (C) 2000, 2001 Kanoj Sarcar
   * Copyright (C) 2000, 2001 Ralf Baechle
   * Copyright (C) 2000, 2001 Silicon Graphics, Inc.
   * Copyright (C) 2000, 2001, 2003 Broadcom Corporation
   */
  #include <linux/cache.h>
  #include <linux/delay.h>
  #include <linux/init.h>
  #include <linux/interrupt.h>

  #include <linux/smp.h>

  #include <linux/spinlock.h>
  #include <linux/threads.h>
  #include <linux/module.h>
  #include <linux/time.h>
  #include <linux/timex.h>
  #include <linux/sched.h>
  #include <linux/cpumask.h>

  #include <linux/cpu.h>

  #include <linux/err.h>

  #include <linux/ftrace.h>

  #include <linux/atomic.h>

  #include <asm/cpu.h>
  #include <asm/processor.h>

  #include <asm/r4k-timer.h>

  #include <asm/system.h>
  #include <asm/mmu_context.h>

  #include <asm/time.h>

  #ifdef CONFIG_MIPS_MT_SMTC
  #include <asm/mipsmtregs.h>
  #endif /* CONFIG_MIPS_MT_SMTC */

  volatile cpumask_t cpu_callin_map;	/* Bitmask of started secondaries */

  int __cpu_number_map[NR_CPUS];		/* Map physical to logical */

  EXPORT_SYMBOL(__cpu_number_map);

  int __cpu_logical_map[NR_CPUS];		/* Map logical to physical */

  EXPORT_SYMBOL(__cpu_logical_map);

  /* Number of TCs (or siblings in Intel speak) per CPU core */
  int smp_num_siblings = 1;
  EXPORT_SYMBOL(smp_num_siblings);
  
  /* representing the TCs (or siblings in Intel speak) of each logical CPU */
  cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly;
  EXPORT_SYMBOL(cpu_sibling_map);
  
  /* representing cpus for which sibling maps can be computed */
  static cpumask_t cpu_sibling_setup_map;
  
  static inline void set_cpu_sibling_map(int cpu)
  {
  	int i;
  
  	cpu_set(cpu, cpu_sibling_setup_map);
  
  	if (smp_num_siblings > 1) {
  		for_each_cpu_mask(i, cpu_sibling_setup_map) {
  			if (cpu_data[cpu].core == cpu_data[i].core) {
  				cpu_set(i, cpu_sibling_map[cpu]);
  				cpu_set(cpu, cpu_sibling_map[i]);
  			}
  		}
  	} else
  		cpu_set(cpu, cpu_sibling_map[cpu]);
  }

  struct plat_smp_ops *mp_ops;
  
  __cpuinit void register_smp_ops(struct plat_smp_ops *ops)
  {

  	if (mp_ops)
  		printk(KERN_WARNING "Overriding previously set SMP ops
  ");

  
  	mp_ops = ops;
  }

  /*
   * First C code run on the secondary CPUs after being started up by
   * the master.
   */

  asmlinkage __cpuinit void start_secondary(void)

  {

  	unsigned int cpu;

  #ifdef CONFIG_MIPS_MT_SMTC
  	/* Only do cpu_probe for first TC of CPU */
  	if ((read_c0_tcbind() & TCBIND_CURTC) == 0)
  #endif /* CONFIG_MIPS_MT_SMTC */

  	cpu_probe();
  	cpu_report();
  	per_cpu_trap_init();

  	mips_clockevent_init();

  	mp_ops->init_secondary();

  
  	/*
  	 * XXX parity protection should be folded in here when it's converted
  	 * to an option instead of something based on .cputype
  	 */
  
  	calibrate_delay();

  	preempt_disable();
  	cpu = smp_processor_id();

  	cpu_data[cpu].udelay_val = loops_per_jiffy;

  	notify_cpu_starting(cpu);

  	mp_ops->smp_finish();

  	set_cpu_sibling_map(cpu);

  
  	cpu_set(cpu, cpu_callin_map);

  	synchronise_count_slave();

  	cpu_idle();
  }

  /*
   * Call into both interrupt handlers, as we share the IPI for them
   */

  void __irq_entry smp_call_function_interrupt(void)

  {

  	irq_enter();

  	generic_smp_call_function_single_interrupt();
  	generic_smp_call_function_interrupt();

  	irq_exit();

  }

  static void stop_this_cpu(void *dummy)
  {
  	/*
  	 * Remove this CPU:
  	 */
  	cpu_clear(smp_processor_id(), cpu_online_map);

  	for (;;) {
  		if (cpu_wait)
  			(*cpu_wait)();		/* Wait if available. */
  	}

  }
  
  void smp_send_stop(void)
  {

  	smp_call_function(stop_this_cpu, NULL, 0);

  }
  
  void __init smp_cpus_done(unsigned int max_cpus)
  {

  	mp_ops->cpus_done();

  	synchronise_count_master();

  }
  
  /* called from main before smp_init() */
  void __init smp_prepare_cpus(unsigned int max_cpus)
  {

  	init_new_context(current, &init_mm);
  	current_thread_info()->cpu = 0;

  	mp_ops->prepare_cpus(max_cpus);

  	set_cpu_sibling_map(0);

  #ifndef CONFIG_HOTPLUG_CPU

  	init_cpu_present(&cpu_possible_map);

  #endif

  }
  
  /* preload SMP state for boot cpu */
  void __devinit smp_prepare_boot_cpu(void)
  {

  	set_cpu_possible(0, true);
  	set_cpu_online(0, true);

  	cpu_set(0, cpu_callin_map);
  }
  
  /*

   * Called once for each "cpu_possible(cpu)".  Needs to spin up the cpu
   * and keep control until "cpu_online(cpu)" is set.  Note: cpu is
   * physical, not logical.

   */

  static struct task_struct *cpu_idle_thread[NR_CPUS];

  struct create_idle {
  	struct work_struct work;
  	struct task_struct *idle;
  	struct completion done;
  	int cpu;
  };
  
  static void __cpuinit do_fork_idle(struct work_struct *work)
  {
  	struct create_idle *c_idle =
  		container_of(work, struct create_idle, work);
  
  	c_idle->idle = fork_idle(c_idle->cpu);
  	complete(&c_idle->done);
  }

  int __cpuinit __cpu_up(unsigned int cpu)

  {
  	struct task_struct *idle;
  
  	/*

  	 * Processor goes to start_secondary(), sets online flag

  	 * The following code is purely to make sure
  	 * Linux can schedule processes on this slave.
  	 */

  	if (!cpu_idle_thread[cpu]) {

  		/*
  		 * Schedule work item to avoid forking user task
  		 * Ported from arch/x86/kernel/smpboot.c
  		 */
  		struct create_idle c_idle = {
  			.cpu    = cpu,
  			.done   = COMPLETION_INITIALIZER_ONSTACK(c_idle.done),
  		};
  
  		INIT_WORK_ONSTACK(&c_idle.work, do_fork_idle);
  		schedule_work(&c_idle.work);
  		wait_for_completion(&c_idle.done);
  		idle = cpu_idle_thread[cpu] = c_idle.idle;

  
  		if (IS_ERR(idle))
  			panic(KERN_ERR "Fork failed for CPU %d", cpu);
  	} else {
  		idle = cpu_idle_thread[cpu];
  		init_idle(idle, cpu);
  	}

  	mp_ops->boot_secondary(cpu, idle);

  	/*
  	 * Trust is futile.  We should really have timeouts ...
  	 */

  	while (!cpu_isset(cpu, cpu_callin_map))
  		udelay(100);
  
  	cpu_set(cpu, cpu_online_map);
  
  	return 0;
  }

  /* Not really SMP stuff ... */
  int setup_profiling_timer(unsigned int multiplier)
  {
  	return 0;
  }
  
  static void flush_tlb_all_ipi(void *info)
  {
  	local_flush_tlb_all();
  }
  
  void flush_tlb_all(void)
  {

  	on_each_cpu(flush_tlb_all_ipi, NULL, 1);

  }
  
  static void flush_tlb_mm_ipi(void *mm)
  {
  	local_flush_tlb_mm((struct mm_struct *)mm);
  }
  
  /*

   * Special Variant of smp_call_function for use by TLB functions:
   *
   *  o No return value
   *  o collapses to normal function call on UP kernels
   *  o collapses to normal function call on systems with a single shared
   *    primary cache.
   *  o CONFIG_MIPS_MT_SMTC currently implies there is only one physical core.
   */
  static inline void smp_on_other_tlbs(void (*func) (void *info), void *info)
  {
  #ifndef CONFIG_MIPS_MT_SMTC

  	smp_call_function(func, info, 1);

  #endif
  }
  
  static inline void smp_on_each_tlb(void (*func) (void *info), void *info)
  {
  	preempt_disable();
  
  	smp_on_other_tlbs(func, info);
  	func(info);
  
  	preempt_enable();
  }
  
  /*

   * The following tlb flush calls are invoked when old translations are
   * being torn down, or pte attributes are changing. For single threaded
   * address spaces, a new context is obtained on the current cpu, and tlb
   * context on other cpus are invalidated to force a new context allocation
   * at switch_mm time, should the mm ever be used on other cpus. For
   * multithreaded address spaces, intercpu interrupts have to be sent.
   * Another case where intercpu interrupts are required is when the target
   * mm might be active on another cpu (eg debuggers doing the flushes on
   * behalf of debugees, kswapd stealing pages from another process etc).
   * Kanoj 07/00.
   */
  
  void flush_tlb_mm(struct mm_struct *mm)
  {
  	preempt_disable();
  
  	if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {

  		smp_on_other_tlbs(flush_tlb_mm_ipi, mm);

  	} else {

  		cpumask_t mask = cpu_online_map;
  		unsigned int cpu;
  
  		cpu_clear(smp_processor_id(), mask);

  		for_each_cpu_mask(cpu, mask)

  			if (cpu_context(cpu, mm))
  				cpu_context(cpu, mm) = 0;

  	}
  	local_flush_tlb_mm(mm);
  
  	preempt_enable();
  }
  
  struct flush_tlb_data {
  	struct vm_area_struct *vma;
  	unsigned long addr1;
  	unsigned long addr2;
  };
  
  static void flush_tlb_range_ipi(void *info)
  {

  	struct flush_tlb_data *fd = info;

  
  	local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
  }
  
  void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
  {
  	struct mm_struct *mm = vma->vm_mm;
  
  	preempt_disable();
  	if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {

  		struct flush_tlb_data fd = {
  			.vma = vma,
  			.addr1 = start,
  			.addr2 = end,
  		};

  		smp_on_other_tlbs(flush_tlb_range_ipi, &fd);

  	} else {

  		cpumask_t mask = cpu_online_map;
  		unsigned int cpu;
  
  		cpu_clear(smp_processor_id(), mask);

  		for_each_cpu_mask(cpu, mask)

  			if (cpu_context(cpu, mm))
  				cpu_context(cpu, mm) = 0;

  	}
  	local_flush_tlb_range(vma, start, end);
  	preempt_enable();
  }
  
  static void flush_tlb_kernel_range_ipi(void *info)
  {

  	struct flush_tlb_data *fd = info;

  
  	local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
  }
  
  void flush_tlb_kernel_range(unsigned long start, unsigned long end)
  {

  	struct flush_tlb_data fd = {
  		.addr1 = start,
  		.addr2 = end,
  	};

  	on_each_cpu(flush_tlb_kernel_range_ipi, &fd, 1);

  }
  
  static void flush_tlb_page_ipi(void *info)
  {

  	struct flush_tlb_data *fd = info;

  
  	local_flush_tlb_page(fd->vma, fd->addr1);
  }
  
  void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
  {
  	preempt_disable();
  	if ((atomic_read(&vma->vm_mm->mm_users) != 1) || (current->mm != vma->vm_mm)) {

  		struct flush_tlb_data fd = {
  			.vma = vma,
  			.addr1 = page,
  		};

  		smp_on_other_tlbs(flush_tlb_page_ipi, &fd);

  	} else {

  		cpumask_t mask = cpu_online_map;
  		unsigned int cpu;
  
  		cpu_clear(smp_processor_id(), mask);

  		for_each_cpu_mask(cpu, mask)

  			if (cpu_context(cpu, vma->vm_mm))
  				cpu_context(cpu, vma->vm_mm) = 0;

  	}
  	local_flush_tlb_page(vma, page);
  	preempt_enable();
  }
  
  static void flush_tlb_one_ipi(void *info)
  {
  	unsigned long vaddr = (unsigned long) info;
  
  	local_flush_tlb_one(vaddr);
  }
  
  void flush_tlb_one(unsigned long vaddr)
  {

  	smp_on_each_tlb(flush_tlb_one_ipi, (void *) vaddr);

  }
  
  EXPORT_SYMBOL(flush_tlb_page);
  EXPORT_SYMBOL(flush_tlb_one);