/*
   * This file is subject to the terms and conditions of the GNU General Public
   * License.  See the file "COPYING" in the main directory of this archive
   * for more details.
   *
   * Copyright (C) 2004-2008, 2009, 2010 Cavium Networks
   */
  #include <linux/cpu.h>
  #include <linux/delay.h>
  #include <linux/smp.h>
  #include <linux/interrupt.h>
  #include <linux/kernel_stat.h>
  #include <linux/sched.h>
  #include <linux/module.h>
  
  #include <asm/mmu_context.h>
  #include <asm/time.h>
  #include <asm/setup.h>
  
  #include <asm/octeon/octeon.h>
  
  #include "octeon_boot.h"
  
  volatile unsigned long octeon_processor_boot = 0xff;
  volatile unsigned long octeon_processor_sp;
  volatile unsigned long octeon_processor_gp;
  
  #ifdef CONFIG_HOTPLUG_CPU
  uint64_t octeon_bootloader_entry_addr;
  EXPORT_SYMBOL(octeon_bootloader_entry_addr);
  #endif
  
  static irqreturn_t mailbox_interrupt(int irq, void *dev_id)
  {
  	const int coreid = cvmx_get_core_num();
  	uint64_t action;
  
  	/* Load the mailbox register to figure out what we're supposed to do */
  	action = cvmx_read_csr(CVMX_CIU_MBOX_CLRX(coreid)) & 0xffff;
  
  	/* Clear the mailbox to clear the interrupt */
  	cvmx_write_csr(CVMX_CIU_MBOX_CLRX(coreid), action);
  
  	if (action & SMP_CALL_FUNCTION)
  		smp_call_function_interrupt();
  	if (action & SMP_RESCHEDULE_YOURSELF)
  		scheduler_ipi();
  
  	/* Check if we've been told to flush the icache */
  	if (action & SMP_ICACHE_FLUSH)
  		asm volatile ("synci 0($0)
  ");
  	return IRQ_HANDLED;
  }
  
  /**
   * Cause the function described by call_data to be executed on the passed
   * cpu.	 When the function has finished, increment the finished field of
   * call_data.
   */
  void octeon_send_ipi_single(int cpu, unsigned int action)
  {
  	int coreid = cpu_logical_map(cpu);
  	/*
  	pr_info("SMP: Mailbox send cpu=%d, coreid=%d, action=%u
  ", cpu,
  	       coreid, action);
  	*/
  	cvmx_write_csr(CVMX_CIU_MBOX_SETX(coreid), action);
  }
  
  static inline void octeon_send_ipi_mask(const struct cpumask *mask,
  					unsigned int action)
  {
  	unsigned int i;
  
  	for_each_cpu_mask(i, *mask)
  		octeon_send_ipi_single(i, action);
  }
  
  /**
   * Detect available CPUs, populate cpu_possible_mask
   */
  static void octeon_smp_hotplug_setup(void)
  {
  #ifdef CONFIG_HOTPLUG_CPU
  	struct linux_app_boot_info *labi;
  
  	labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
  	if (labi->labi_signature != LABI_SIGNATURE)
  		panic("The bootloader version on this board is incorrect.");
  
  	octeon_bootloader_entry_addr = labi->InitTLBStart_addr;
  #endif
  }
  
  static void octeon_smp_setup(void)
  {
  	const int coreid = cvmx_get_core_num();
  	int cpus;
  	int id;
  	int core_mask = octeon_get_boot_coremask();
  #ifdef CONFIG_HOTPLUG_CPU
  	unsigned int num_cores = cvmx_octeon_num_cores();
  #endif
  
  	/* The present CPUs are initially just the boot cpu (CPU 0). */
  	for (id = 0; id < NR_CPUS; id++) {
  		set_cpu_possible(id, id == 0);
  		set_cpu_present(id, id == 0);
  	}
  
  	__cpu_number_map[coreid] = 0;
  	__cpu_logical_map[0] = coreid;
  
  	/* The present CPUs get the lowest CPU numbers. */
  	cpus = 1;
  	for (id = 0; id < NR_CPUS; id++) {
  		if ((id != coreid) && (core_mask & (1 << id))) {
  			set_cpu_possible(cpus, true);
  			set_cpu_present(cpus, true);
  			__cpu_number_map[id] = cpus;
  			__cpu_logical_map[cpus] = id;
  			cpus++;
  		}
  	}
  
  #ifdef CONFIG_HOTPLUG_CPU
  	/*
  	 * The possible CPUs are all those present on the chip.	 We
  	 * will assign CPU numbers for possible cores as well.	Cores
  	 * are always consecutively numberd from 0.
  	 */
  	for (id = 0; id < num_cores && id < NR_CPUS; id++) {
  		if (!(core_mask & (1 << id))) {
  			set_cpu_possible(cpus, true);
  			__cpu_number_map[id] = cpus;
  			__cpu_logical_map[cpus] = id;
  			cpus++;
  		}
  	}
  #endif
  
  	octeon_smp_hotplug_setup();
  }
  
  /**
   * Firmware CPU startup hook
   *
   */
  static void octeon_boot_secondary(int cpu, struct task_struct *idle)
  {
  	int count;
  
  	pr_info("SMP: Booting CPU%02d (CoreId %2d)...
  ", cpu,
  		cpu_logical_map(cpu));
  
  	octeon_processor_sp = __KSTK_TOS(idle);
  	octeon_processor_gp = (unsigned long)(task_thread_info(idle));
  	octeon_processor_boot = cpu_logical_map(cpu);
  	mb();
  
  	count = 10000;
  	while (octeon_processor_sp && count) {
  		/* Waiting for processor to get the SP and GP */
  		udelay(1);
  		count--;
  	}
  	if (count == 0)
  		pr_err("Secondary boot timeout
  ");
  }
  
  /**
   * After we've done initial boot, this function is called to allow the
   * board code to clean up state, if needed
   */
  static void octeon_init_secondary(void)
  {
  	unsigned int sr;
  
  	sr = set_c0_status(ST0_BEV);
  	write_c0_ebase((u32)ebase);
  	write_c0_status(sr);
  
  	octeon_check_cpu_bist();
  	octeon_init_cvmcount();
  
  	octeon_irq_setup_secondary();
  }
  
  /**
   * Callout to firmware before smp_init
   *
   */
  void octeon_prepare_cpus(unsigned int max_cpus)
  {
  #ifdef CONFIG_HOTPLUG_CPU
  	struct linux_app_boot_info *labi;
  
  	labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
  
  	if (labi->labi_signature != LABI_SIGNATURE)
  		panic("The bootloader version on this board is incorrect.");
  #endif
  	/*
  	 * Only the low order mailbox bits are used for IPIs, leave
  	 * the other bits alone.
  	 */
  	cvmx_write_csr(CVMX_CIU_MBOX_CLRX(cvmx_get_core_num()), 0xffff);
  	if (request_irq(OCTEON_IRQ_MBOX0, mailbox_interrupt,
  			IRQF_PERCPU | IRQF_NO_THREAD, "SMP-IPI",
  			mailbox_interrupt)) {
  		panic("Cannot request_irq(OCTEON_IRQ_MBOX0)");
  	}
  }
  
  /**
   * Last chance for the board code to finish SMP initialization before
   * the CPU is "online".
   */
  static void octeon_smp_finish(void)
  {
  #ifdef CONFIG_CAVIUM_GDB
  	unsigned long tmp;
  	/* Pulse MCD0 signal on Ctrl-C to stop all the cores. Also set the MCD0
  	   to be not masked by this core so we know the signal is received by
  	   someone */
  	asm volatile ("dmfc0 %0, $22
  "
  		      "ori   %0, %0, 0x9100
  " "dmtc0 %0, $22
  " : "=r" (tmp));
  #endif
  
  	octeon_user_io_init();
  
  	/* to generate the first CPU timer interrupt */
  	write_c0_compare(read_c0_count() + mips_hpt_frequency / HZ);
  	local_irq_enable();
  }
  
  /**
   * Hook for after all CPUs are online
   */
  static void octeon_cpus_done(void)
  {
  #ifdef CONFIG_CAVIUM_GDB
  	unsigned long tmp;
  	/* Pulse MCD0 signal on Ctrl-C to stop all the cores. Also set the MCD0
  	   to be not masked by this core so we know the signal is received by
  	   someone */
  	asm volatile ("dmfc0 %0, $22
  "
  		      "ori   %0, %0, 0x9100
  " "dmtc0 %0, $22
  " : "=r" (tmp));
  #endif
  }
  
  #ifdef CONFIG_HOTPLUG_CPU
  
  /* State of each CPU. */
  DEFINE_PER_CPU(int, cpu_state);
  
  static int octeon_cpu_disable(void)
  {
  	unsigned int cpu = smp_processor_id();
  
  	if (cpu == 0)
  		return -EBUSY;
  
  	set_cpu_online(cpu, false);
  	cpu_clear(cpu, cpu_callin_map);
  	local_irq_disable();
  	octeon_fixup_irqs();
  	local_irq_enable();
  
  	flush_cache_all();
  	local_flush_tlb_all();
  
  	return 0;
  }
  
  static void octeon_cpu_die(unsigned int cpu)
  {
  	int coreid = cpu_logical_map(cpu);
  	uint32_t mask, new_mask;
  	const struct cvmx_bootmem_named_block_desc *block_desc;
  
  	while (per_cpu(cpu_state, cpu) != CPU_DEAD)
  		cpu_relax();
  
  	/*
  	 * This is a bit complicated strategics of getting/settig available
  	 * cores mask, copied from bootloader
  	 */
  
  	mask = 1 << coreid;
  	/* LINUX_APP_BOOT_BLOCK is initialized in bootoct binary */
  	block_desc = cvmx_bootmem_find_named_block(LINUX_APP_BOOT_BLOCK_NAME);
  
  	if (!block_desc) {
  		struct linux_app_boot_info *labi;
  
  		labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
  
  		labi->avail_coremask |= mask;
  		new_mask = labi->avail_coremask;
  	} else {		       /* alternative, already initialized */
  		uint32_t *p = (uint32_t *)PHYS_TO_XKSEG_CACHED(block_desc->base_addr +
  							       AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK);
  		*p |= mask;
  		new_mask = *p;
  	}
  
  	pr_info("Reset core %d. Available Coremask = 0x%x 
  ", coreid, new_mask);
  	mb();
  	cvmx_write_csr(CVMX_CIU_PP_RST, 1 << coreid);
  	cvmx_write_csr(CVMX_CIU_PP_RST, 0);
  }
  
  void play_dead(void)
  {
  	int cpu = cpu_number_map(cvmx_get_core_num());
  
  	idle_task_exit();
  	octeon_processor_boot = 0xff;
  	per_cpu(cpu_state, cpu) = CPU_DEAD;
  
  	mb();
  
  	while (1)	/* core will be reset here */
  		;
  }
  
  extern void kernel_entry(unsigned long arg1, ...);
  
  static void start_after_reset(void)
  {
  	kernel_entry(0, 0, 0);	/* set a2 = 0 for secondary core */
  }
  
  static int octeon_update_boot_vector(unsigned int cpu)
  {
  
  	int coreid = cpu_logical_map(cpu);
  	uint32_t avail_coremask;
  	const struct cvmx_bootmem_named_block_desc *block_desc;
  	struct boot_init_vector *boot_vect =
  		(struct boot_init_vector *)PHYS_TO_XKSEG_CACHED(BOOTLOADER_BOOT_VECTOR);
  
  	block_desc = cvmx_bootmem_find_named_block(LINUX_APP_BOOT_BLOCK_NAME);
  
  	if (!block_desc) {
  		struct linux_app_boot_info *labi;
  
  		labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
  
  		avail_coremask = labi->avail_coremask;
  		labi->avail_coremask &= ~(1 << coreid);
  	} else {		       /* alternative, already initialized */
  		avail_coremask = *(uint32_t *)PHYS_TO_XKSEG_CACHED(
  			block_desc->base_addr + AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK);
  	}
  
  	if (!(avail_coremask & (1 << coreid))) {
  		/* core not available, assume, that catched by simple-executive */
  		cvmx_write_csr(CVMX_CIU_PP_RST, 1 << coreid);
  		cvmx_write_csr(CVMX_CIU_PP_RST, 0);
  	}
  
  	boot_vect[coreid].app_start_func_addr =
  		(uint32_t) (unsigned long) start_after_reset;
  	boot_vect[coreid].code_addr = octeon_bootloader_entry_addr;
  
  	mb();
  
  	cvmx_write_csr(CVMX_CIU_NMI, (1 << coreid) & avail_coremask);
  
  	return 0;
  }
  
  static int octeon_cpu_callback(struct notifier_block *nfb,
  	unsigned long action, void *hcpu)
  {
  	unsigned int cpu = (unsigned long)hcpu;
  
  	switch (action) {
  	case CPU_UP_PREPARE:
  		octeon_update_boot_vector(cpu);
  		break;
  	case CPU_ONLINE:
  		pr_info("Cpu %d online
  ", cpu);
  		break;
  	case CPU_DEAD:
  		break;
  	}
  
  	return NOTIFY_OK;
  }
  
  static int register_cavium_notifier(void)
  {
  	hotcpu_notifier(octeon_cpu_callback, 0);
  	return 0;
  }
  late_initcall(register_cavium_notifier);
  
  #endif	/* CONFIG_HOTPLUG_CPU */
  
  struct plat_smp_ops octeon_smp_ops = {
  	.send_ipi_single	= octeon_send_ipi_single,
  	.send_ipi_mask		= octeon_send_ipi_mask,
  	.init_secondary		= octeon_init_secondary,
  	.smp_finish		= octeon_smp_finish,
  	.cpus_done		= octeon_cpus_done,
  	.boot_secondary		= octeon_boot_secondary,
  	.smp_setup		= octeon_smp_setup,
  	.prepare_cpus		= octeon_prepare_cpus,
  #ifdef CONFIG_HOTPLUG_CPU
  	.cpu_disable		= octeon_cpu_disable,
  	.cpu_die		= octeon_cpu_die,
  #endif
  };