arch/sparc/kernel/leon_smp.c - third_party/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /* 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/mm.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 <linux/cpu.h>
 #include <linux/clockchips.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 <asm/timer.h>

 #include "kernel.h"

 #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 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\n\t" : "=&r"(val)
 			     : "0"(val), "r"(ptr), "i"(ASI_LEON_DCACHE_MISS)
 			     : "memory");
 	return val;
 }

 void leon_cpu_pre_starting(void *arg)
 {
 	leon_configure_cache_smp();
 }

 void leon_cpu_pre_online(void *arg)
 {
 	int cpuid = hard_smp_processor_id();

 	/* Allow master to continue. The master will then give us the
 	 * go-ahead by setting the smp_commenced_mask and will wait without
 	 * timeouts until our setup is completed fully (signified by
 	 * our bit being set in the cpu_online_mask).
 	 */
 	do_swap(&cpu_callin_map[cpuid], 1);

 	local_ops->cache_all();
 	local_ops->tlb_all();

 	/* Fix idle thread fields. */
 	__asm__ __volatile__("ld [%0], %%g6\n\t" : : "r"(&current_set[cpuid])
 			     : "memory" /* paranoid */);

 	/* Attach to the address space of init_task. */
 	mmgrab(&init_mm);
 	current->active_mm = &init_mm;

 	while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
 		mb();
 }

 /*
  *	Cycle through the processors asking the PROM to start each one.
  */

 extern struct linux_prom_registers smp_penguin_ctable;

 void 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\n",
 		     (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\n",
 			     me);
 			sparc_leon3_disable_cache();
 		}
 	}

 	local_ops->cache_all();
 	local_ops->tlb_all();
 }

 static 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\n",
 		     leon_smp_nrcpus());
 		if (leon_smp_nrcpus() > 1) {
 			BUG();
 		} else {
 			prom_printf("continue anyway\n");
 			return;
 		}
 	}
 	LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpbroadcast), 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\n", (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();
 	local_ops->cache_all();

 }

 int leon_boot_one_cpu(int i, struct task_struct *idle)
 {
 	int timeout;

 	current_set[i] = task_thread_info(idle);

 	/* 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)\n", (unsigned int)i,
 	       (unsigned int)&leon3_irqctrl_regs->mpstatus);
 	local_ops->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\n", (unsigned int)i);

 	if (!(cpu_callin_map[i])) {
 		printk(KERN_ERR "Processor %d is stuck.\n", 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_ops->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_ops->cache_all();

 	/* Free unneeded trap tables */
 	if (!cpu_present(1)) {
 		free_reserved_page(virt_to_page(&trapbase_cpu1));
 	}
 	if (!cpu_present(2)) {
 		free_reserved_page(virt_to_page(&trapbase_cpu2));
 	}
 	if (!cpu_present(3)) {
 		free_reserved_page(virt_to_page(&trapbase_cpu3));
 	}
 	/* Ok, they are spinning and ready to go. */
 	smp_processors_ready = 1;

 }

 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\n", 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_ops->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_send_ipi(int cpu, int level)
 {
 	unsigned long mask;
 	mask = leon_get_irqmask(level);
 	LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->force[cpu], mask);
 }

 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 */
 	leon_send_ipi(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 */
 	leon_send_ipi(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) */
 	leon_send_ipi(cpu, leon_ipi_irq);
 }

 void leonsmp_ipi_interrupt(void)
 {
 	struct leon_ipi_work *work = this_cpu_ptr(&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 __attribute__((aligned(8)));

 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]\n\t"
 					     "std %2, [%6 + 8]\n\t"
 					     "std %4, [%6 + 16]\n\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;
 					leon_send_ipi(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;
 }

 static const struct sparc32_ipi_ops leon_ipi_ops = {
 	.cross_call = leon_cross_call,
 	.resched    = leon_ipi_resched,
 	.single     = leon_ipi_single,
 	.mask_one   = leon_ipi_mask_one,
 };

 void __init leon_init_smp(void)
 {
 	/* Patch ipi15 trap table */
 	t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_leon - linux_trap_ipi15_sun4m);

 	sparc32_ipi_ops = &leon_ipi_ops;
 }
	// SPDX-License-Identifier: GPL-2.0
	/* 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/mm.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 <linux/cpu.h>
	#include <linux/clockchips.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 <asm/timer.h>

	#include "kernel.h"

	#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 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\n\t" : "=&r"(val)
	: "0"(val), "r"(ptr), "i"(ASI_LEON_DCACHE_MISS)
	: "memory");
	return val;
	}

	void leon_cpu_pre_starting(void *arg)
	{
	leon_configure_cache_smp();
	}

	void leon_cpu_pre_online(void *arg)
	{
	int cpuid = hard_smp_processor_id();

	/* Allow master to continue. The master will then give us the
	* go-ahead by setting the smp_commenced_mask and will wait without
	* timeouts until our setup is completed fully (signified by
	* our bit being set in the cpu_online_mask).
	*/
	do_swap(&cpu_callin_map[cpuid], 1);

	local_ops->cache_all();
	local_ops->tlb_all();

	/* Fix idle thread fields. */
	__asm__ __volatile__("ld [%0], %%g6\n\t" : : "r"(&current_set[cpuid])
	: "memory" /* paranoid */);

	/* Attach to the address space of init_task. */
	mmgrab(&init_mm);
	current->active_mm = &init_mm;

	while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
	mb();
	}

	/*
	* Cycle through the processors asking the PROM to start each one.
	*/

	extern struct linux_prom_registers smp_penguin_ctable;

	void 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\n",
	(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\n",
	me);
	sparc_leon3_disable_cache();
	}
	}

	local_ops->cache_all();
	local_ops->tlb_all();
	}

	static 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\n",
	leon_smp_nrcpus());
	if (leon_smp_nrcpus() > 1) {
	BUG();
	} else {
	prom_printf("continue anyway\n");
	return;
	}
	}
	LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpbroadcast), 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\n", (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();
	local_ops->cache_all();

	}

	int leon_boot_one_cpu(int i, struct task_struct *idle)
	{
	int timeout;

	current_set[i] = task_thread_info(idle);

	/* 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)\n", (unsigned int)i,
	(unsigned int)&leon3_irqctrl_regs->mpstatus);
	local_ops->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\n", (unsigned int)i);

	if (!(cpu_callin_map[i])) {
	printk(KERN_ERR "Processor %d is stuck.\n", 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_ops->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_ops->cache_all();

	/* Free unneeded trap tables */
	if (!cpu_present(1)) {
	free_reserved_page(virt_to_page(&trapbase_cpu1));
	}
	if (!cpu_present(2)) {
	free_reserved_page(virt_to_page(&trapbase_cpu2));
	}
	if (!cpu_present(3)) {
	free_reserved_page(virt_to_page(&trapbase_cpu3));
	}
	/* Ok, they are spinning and ready to go. */
	smp_processors_ready = 1;

	}

	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\n", 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_ops->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_send_ipi(int cpu, int level)
	{
	unsigned long mask;
	mask = leon_get_irqmask(level);
	LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->force[cpu], mask);
	}

	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 */
	leon_send_ipi(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 */
	leon_send_ipi(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) */
	leon_send_ipi(cpu, leon_ipi_irq);
	}

	void leonsmp_ipi_interrupt(void)
	{
	struct leon_ipi_work *work = this_cpu_ptr(&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 __attribute__((aligned(8)));

	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]\n\t"
	"std %2, [%6 + 8]\n\t"
	"std %4, [%6 + 16]\n\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;
	leon_send_ipi(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;
	}

	static const struct sparc32_ipi_ops leon_ipi_ops = {
	.cross_call = leon_cross_call,
	.resched = leon_ipi_resched,
	.single = leon_ipi_single,
	.mask_one = leon_ipi_mask_one,
	};

	void __init leon_init_smp(void)
	{
	/* Patch ipi15 trap table */
	t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_leon - linux_trap_ipi15_sun4m);

	sparc32_ipi_ops = &leon_ipi_ops;
	}