/* leon_smp.c: Sparc-Leon SMP support.
   *
   * based on sun4m_smp.c
   * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
   * Copyright (C) 2009 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
   * Copyright (C) 2009 Konrad Eisele (konrad@gaisler.com) Aeroflex Gaisler AB
   */
  
  #include <asm/head.h>
  
  #include <linux/kernel.h>
  #include <linux/sched.h>
  #include <linux/threads.h>
  #include <linux/smp.h>

  #include <linux/interrupt.h>
  #include <linux/kernel_stat.h>

  #include <linux/of.h>

  #include <linux/init.h>
  #include <linux/spinlock.h>
  #include <linux/mm.h>
  #include <linux/swap.h>
  #include <linux/profile.h>
  #include <linux/pm.h>
  #include <linux/delay.h>

  #include <linux/gfp.h>

  
  #include <asm/cacheflush.h>
  #include <asm/tlbflush.h>
  
  #include <asm/ptrace.h>

  #include <linux/atomic.h>

  #include <asm/irq_regs.h>

  #include <asm/traps.h>

  
  #include <asm/delay.h>
  #include <asm/irq.h>
  #include <asm/page.h>
  #include <asm/pgalloc.h>
  #include <asm/pgtable.h>
  #include <asm/oplib.h>
  #include <asm/cpudata.h>
  #include <asm/asi.h>
  #include <asm/leon.h>
  #include <asm/leon_amba.h>

  #include "kernel.h"

  #ifdef CONFIG_SPARC_LEON
  
  #include "irq.h"
  
  extern ctxd_t *srmmu_ctx_table_phys;
  static int smp_processors_ready;
  extern volatile unsigned long cpu_callin_map[NR_CPUS];

  extern cpumask_t smp_commenced_mask;
  void __init leon_configure_cache_smp(void);

  static void leon_ipi_init(void);
  
  /* IRQ number of LEON IPIs */
  int leon_ipi_irq = LEON3_IRQ_IPI_DEFAULT;

  
  static inline unsigned long do_swap(volatile unsigned long *ptr,
  				    unsigned long val)
  {

  	__asm__ __volatile__("swapa [%2] %3, %0
  \t" : "=&r"(val)
  			     : "0"(val), "r"(ptr), "i"(ASI_LEON_DCACHE_MISS)

  			     : "memory");
  	return val;
  }
  
  static void smp_setup_percpu_timer(void);
  
  void __cpuinit leon_callin(void)
  {
  	int cpuid = hard_smpleon_processor_id();
  
  	local_flush_cache_all();
  	local_flush_tlb_all();
  	leon_configure_cache_smp();
  
  	/* Get our local ticker going. */
  	smp_setup_percpu_timer();
  
  	calibrate_delay();
  	smp_store_cpu_info(cpuid);
  
  	local_flush_cache_all();
  	local_flush_tlb_all();
  
  	/*
  	 * Unblock the master CPU _only_ when the scheduler state
  	 * of all secondary CPUs will be up-to-date, so after
  	 * the SMP initialization the master will be just allowed
  	 * to call the scheduler code.
  	 * Allow master to continue.
  	 */
  	do_swap(&cpu_callin_map[cpuid], 1);
  
  	local_flush_cache_all();
  	local_flush_tlb_all();

  	/* Fix idle thread fields. */
  	__asm__ __volatile__("ld [%0], %%g6
  \t" : : "r"(&current_set[cpuid])
  			     : "memory" /* paranoid */);
  
  	/* Attach to the address space of init_task. */
  	atomic_inc(&init_mm.mm_count);
  	current->active_mm = &init_mm;

  	while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))

  		mb();
  
  	local_irq_enable();

  	set_cpu_online(cpuid, true);

  }
  
  /*
   *	Cycle through the processors asking the PROM to start each one.
   */
  
  extern struct linux_prom_registers smp_penguin_ctable;
  
  void __init leon_configure_cache_smp(void)
  {
  	unsigned long cfg = sparc_leon3_get_dcachecfg();
  	int me = smp_processor_id();
  
  	if (ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg) > 4) {
  		printk(KERN_INFO "Note: SMP with snooping only works on 4k cache, found %dk(0x%x) on cpu %d, disabling caches
  ",
  		     (unsigned int)ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg),
  		     (unsigned int)cfg, (unsigned int)me);
  		sparc_leon3_disable_cache();
  	} else {
  		if (cfg & ASI_LEON3_SYSCTRL_CFG_SNOOPING) {
  			sparc_leon3_enable_snooping();
  		} else {
  			printk(KERN_INFO "Note: You have to enable snooping in the vhdl model cpu %d, disabling caches
  ",
  			     me);
  			sparc_leon3_disable_cache();
  		}
  	}
  
  	local_flush_cache_all();
  	local_flush_tlb_all();
  }
  
  void leon_smp_setbroadcast(unsigned int mask)
  {
  	int broadcast =
  	    ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
  	      LEON3_IRQMPSTATUS_BROADCAST) & 1);
  	if (!broadcast) {
  		prom_printf("######## !!!! The irqmp-ctrl must have broadcast enabled, smp wont work !!!!! ####### nr cpus: %d
  ",
  		     leon_smp_nrcpus());
  		if (leon_smp_nrcpus() > 1) {
  			BUG();
  		} else {
  			prom_printf("continue anyway
  ");
  			return;
  		}
  	}
  	LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpbroadcast), mask);
  }
  
  unsigned int leon_smp_getbroadcast(void)
  {
  	unsigned int mask;
  	mask = LEON_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpbroadcast));
  	return mask;
  }
  
  int leon_smp_nrcpus(void)
  {
  	int nrcpu =
  	    ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
  	      LEON3_IRQMPSTATUS_CPUNR) & 0xf) + 1;
  	return nrcpu;
  }
  
  void __init leon_boot_cpus(void)
  {
  	int nrcpu = leon_smp_nrcpus();
  	int me = smp_processor_id();

  	/* Setup IPI */
  	leon_ipi_init();

  	printk(KERN_INFO "%d:(%d:%d) cpus mpirq at 0x%x
  ", (unsigned int)me,

  	       (unsigned int)nrcpu, (unsigned int)NR_CPUS,
  	       (unsigned int)&(leon3_irqctrl_regs->mpstatus));
  
  	leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, me);
  	leon_enable_irq_cpu(LEON3_IRQ_TICKER, me);

  	leon_enable_irq_cpu(leon_ipi_irq, me);

  
  	leon_smp_setbroadcast(1 << LEON3_IRQ_TICKER);
  
  	leon_configure_cache_smp();
  	smp_setup_percpu_timer();
  	local_flush_cache_all();
  
  }
  
  int __cpuinit leon_boot_one_cpu(int i)
  {
  
  	struct task_struct *p;
  	int timeout;
  
  	/* Cook up an idler for this guy. */
  	p = fork_idle(i);
  
  	current_set[i] = task_thread_info(p);
  
  	/* See trampoline.S:leon_smp_cpu_startup for details...
  	 * Initialize the contexts table
  	 * Since the call to prom_startcpu() trashes the structure,
  	 * we need to re-initialize it for each cpu
  	 */
  	smp_penguin_ctable.which_io = 0;
  	smp_penguin_ctable.phys_addr = (unsigned int)srmmu_ctx_table_phys;
  	smp_penguin_ctable.reg_size = 0;
  
  	/* whirrr, whirrr, whirrrrrrrrr... */
  	printk(KERN_INFO "Starting CPU %d : (irqmp: 0x%x)
  ", (unsigned int)i,
  	       (unsigned int)&leon3_irqctrl_regs->mpstatus);
  	local_flush_cache_all();

  	/* Make sure all IRQs are of from the start for this new CPU */
  	LEON_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[i], 0);
  
  	/* Wake one CPU */

  	LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpstatus), 1 << i);
  
  	/* wheee... it's going... */
  	for (timeout = 0; timeout < 10000; timeout++) {
  		if (cpu_callin_map[i])
  			break;
  		udelay(200);
  	}

  	printk(KERN_INFO "Started CPU %d
  ", (unsigned int)i);

  
  	if (!(cpu_callin_map[i])) {
  		printk(KERN_ERR "Processor %d is stuck.
  ", i);
  		return -ENODEV;
  	} else {
  		leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, i);
  		leon_enable_irq_cpu(LEON3_IRQ_TICKER, i);

  		leon_enable_irq_cpu(leon_ipi_irq, i);

  	}
  
  	local_flush_cache_all();
  	return 0;
  }
  
  void __init leon_smp_done(void)
  {
  
  	int i, first;
  	int *prev;
  
  	/* setup cpu list for irq rotation */
  	first = 0;
  	prev = &first;
  	for (i = 0; i < NR_CPUS; i++) {
  		if (cpu_online(i)) {
  			*prev = i;
  			prev = &cpu_data(i).next;
  		}
  	}
  	*prev = first;
  	local_flush_cache_all();
  
  	/* Free unneeded trap tables */

  	if (!cpu_present(1)) {

  		ClearPageReserved(virt_to_page(&trapbase_cpu1));
  		init_page_count(virt_to_page(&trapbase_cpu1));
  		free_page((unsigned long)&trapbase_cpu1);

  		totalram_pages++;
  		num_physpages++;
  	}

  	if (!cpu_present(2)) {

  		ClearPageReserved(virt_to_page(&trapbase_cpu2));
  		init_page_count(virt_to_page(&trapbase_cpu2));
  		free_page((unsigned long)&trapbase_cpu2);

  		totalram_pages++;
  		num_physpages++;
  	}

  	if (!cpu_present(3)) {

  		ClearPageReserved(virt_to_page(&trapbase_cpu3));
  		init_page_count(virt_to_page(&trapbase_cpu3));
  		free_page((unsigned long)&trapbase_cpu3);

  		totalram_pages++;
  		num_physpages++;
  	}
  	/* Ok, they are spinning and ready to go. */
  	smp_processors_ready = 1;
  
  }
  
  void leon_irq_rotate(int cpu)
  {
  }

  struct leon_ipi_work {
  	int single;
  	int msk;
  	int resched;
  };
  
  static DEFINE_PER_CPU_SHARED_ALIGNED(struct leon_ipi_work, leon_ipi_work);
  
  /* Initialize IPIs on the LEON, in order to save IRQ resources only one IRQ
   * is used for all three types of IPIs.
   */
  static void __init leon_ipi_init(void)
  {
  	int cpu, len;
  	struct leon_ipi_work *work;
  	struct property *pp;
  	struct device_node *rootnp;
  	struct tt_entry *trap_table;
  	unsigned long flags;
  
  	/* Find IPI IRQ or stick with default value */
  	rootnp = of_find_node_by_path("/ambapp0");
  	if (rootnp) {
  		pp = of_find_property(rootnp, "ipi_num", &len);
  		if (pp && (*(int *)pp->value))
  			leon_ipi_irq = *(int *)pp->value;
  	}
  	printk(KERN_INFO "leon: SMP IPIs at IRQ %d
  ", leon_ipi_irq);
  
  	/* Adjust so that we jump directly to smpleon_ipi */
  	local_irq_save(flags);
  	trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (leon_ipi_irq - 1)];
  	trap_table->inst_three += smpleon_ipi - real_irq_entry;
  	local_flush_cache_all();
  	local_irq_restore(flags);
  
  	for_each_possible_cpu(cpu) {
  		work = &per_cpu(leon_ipi_work, cpu);
  		work->single = work->msk = work->resched = 0;
  	}
  }
  
  static void leon_ipi_single(int cpu)
  {
  	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
  
  	/* Mark work */
  	work->single = 1;
  
  	/* Generate IRQ on the CPU */
  	set_cpu_int(cpu, leon_ipi_irq);
  }
  
  static void leon_ipi_mask_one(int cpu)
  {
  	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
  
  	/* Mark work */
  	work->msk = 1;
  
  	/* Generate IRQ on the CPU */
  	set_cpu_int(cpu, leon_ipi_irq);
  }
  
  static void leon_ipi_resched(int cpu)
  {
  	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
  
  	/* Mark work */
  	work->resched = 1;
  
  	/* Generate IRQ on the CPU (any IRQ will cause resched) */
  	set_cpu_int(cpu, leon_ipi_irq);
  }
  
  void leonsmp_ipi_interrupt(void)
  {
  	struct leon_ipi_work *work = &__get_cpu_var(leon_ipi_work);
  
  	if (work->single) {
  		work->single = 0;
  		smp_call_function_single_interrupt();
  	}
  	if (work->msk) {
  		work->msk = 0;
  		smp_call_function_interrupt();
  	}
  	if (work->resched) {
  		work->resched = 0;
  		smp_resched_interrupt();
  	}
  }

  static struct smp_funcall {
  	smpfunc_t func;
  	unsigned long arg1;
  	unsigned long arg2;
  	unsigned long arg3;
  	unsigned long arg4;
  	unsigned long arg5;
  	unsigned long processors_in[NR_CPUS];	/* Set when ipi entered. */
  	unsigned long processors_out[NR_CPUS];	/* Set when ipi exited. */
  } ccall_info;
  
  static DEFINE_SPINLOCK(cross_call_lock);
  
  /* Cross calls must be serialized, at least currently. */
  static void leon_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
  			    unsigned long arg2, unsigned long arg3,
  			    unsigned long arg4)
  {
  	if (smp_processors_ready) {
  		register int high = NR_CPUS - 1;
  		unsigned long flags;
  
  		spin_lock_irqsave(&cross_call_lock, flags);
  
  		{
  			/* If you make changes here, make sure gcc generates proper code... */
  			register smpfunc_t f asm("i0") = func;
  			register unsigned long a1 asm("i1") = arg1;
  			register unsigned long a2 asm("i2") = arg2;
  			register unsigned long a3 asm("i3") = arg3;
  			register unsigned long a4 asm("i4") = arg4;
  			register unsigned long a5 asm("i5") = 0;
  
  			__asm__ __volatile__("std %0, [%6]
  \t"
  					     "std %2, [%6 + 8]
  \t"
  					     "std %4, [%6 + 16]
  \t" : :
  					     "r"(f), "r"(a1), "r"(a2), "r"(a3),
  					     "r"(a4), "r"(a5),
  					     "r"(&ccall_info.func));
  		}
  
  		/* Init receive/complete mapping, plus fire the IPI's off. */
  		{
  			register int i;

  			cpumask_clear_cpu(smp_processor_id(), &mask);
  			cpumask_and(&mask, cpu_online_mask, &mask);

  			for (i = 0; i <= high; i++) {

  				if (cpumask_test_cpu(i, &mask)) {

  					ccall_info.processors_in[i] = 0;
  					ccall_info.processors_out[i] = 0;
  					set_cpu_int(i, LEON3_IRQ_CROSS_CALL);
  
  				}
  			}
  		}
  
  		{
  			register int i;
  
  			i = 0;
  			do {

  				if (!cpumask_test_cpu(i, &mask))

  					continue;
  
  				while (!ccall_info.processors_in[i])
  					barrier();
  			} while (++i <= high);
  
  			i = 0;
  			do {

  				if (!cpumask_test_cpu(i, &mask))

  					continue;
  
  				while (!ccall_info.processors_out[i])
  					barrier();
  			} while (++i <= high);
  		}
  
  		spin_unlock_irqrestore(&cross_call_lock, flags);
  	}
  }
  
  /* Running cross calls. */
  void leon_cross_call_irq(void)
  {
  	int i = smp_processor_id();
  
  	ccall_info.processors_in[i] = 1;
  	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
  			ccall_info.arg4, ccall_info.arg5);
  	ccall_info.processors_out[i] = 1;
  }

  irqreturn_t leon_percpu_timer_interrupt(int irq, void *unused)

  {

  	int cpu = smp_processor_id();

  	leon_clear_profile_irq(cpu);
  
  	profile_tick(CPU_PROFILING);
  
  	if (!--prof_counter(cpu)) {

  		int user = user_mode(get_irq_regs());

  		update_process_times(user);

  
  		prof_counter(cpu) = prof_multiplier(cpu);
  	}

  
  	return IRQ_HANDLED;

  }
  
  static void __init smp_setup_percpu_timer(void)
  {
  	int cpu = smp_processor_id();
  
  	prof_counter(cpu) = prof_multiplier(cpu) = 1;
  }
  
  void __init leon_blackbox_id(unsigned *addr)
  {
  	int rd = *addr & 0x3e000000;
  	int rs1 = rd >> 11;
  
  	/* patch places where ___b_hard_smp_processor_id appears */
  	addr[0] = 0x81444000 | rd;	/* rd %asr17, reg */
  	addr[1] = 0x8130201c | rd | rs1;	/* srl reg, 0x1c, reg */
  	addr[2] = 0x01000000;	/* nop */
  }
  
  void __init leon_blackbox_current(unsigned *addr)
  {
  	int rd = *addr & 0x3e000000;
  	int rs1 = rd >> 11;
  
  	/* patch LOAD_CURRENT macro where ___b_load_current appears */
  	addr[0] = 0x81444000 | rd;	/* rd %asr17, reg */
  	addr[2] = 0x8130201c | rd | rs1;	/* srl reg, 0x1c, reg */
  	addr[4] = 0x81282002 | rd | rs1;	/* sll reg, 0x2, reg */
  
  }

  void __init leon_init_smp(void)
  {
  	/* Patch ipi15 trap table */
  	t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_leon - linux_trap_ipi15_sun4m);
  
  	BTFIXUPSET_BLACKBOX(hard_smp_processor_id, leon_blackbox_id);
  	BTFIXUPSET_BLACKBOX(load_current, leon_blackbox_current);
  	BTFIXUPSET_CALL(smp_cross_call, leon_cross_call, BTFIXUPCALL_NORM);
  	BTFIXUPSET_CALL(__hard_smp_processor_id, __leon_processor_id,
  			BTFIXUPCALL_NORM);

  	BTFIXUPSET_CALL(smp_ipi_resched, leon_ipi_resched, BTFIXUPCALL_NORM);
  	BTFIXUPSET_CALL(smp_ipi_single, leon_ipi_single, BTFIXUPCALL_NORM);
  	BTFIXUPSET_CALL(smp_ipi_mask_one, leon_ipi_mask_one, BTFIXUPCALL_NORM);

  }
  
  #endif /* CONFIG_SPARC_LEON */