1 files changed, 762 insertions, 0 deletions

diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c
new file mode 100644
index 000000000..f4e20f754
--- /dev/null
+++ b/arch/alpha/kernel/smp.c
@@ -0,0 +1,762 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *	linux/arch/alpha/kernel/smp.c
+ *
+ *      2001-07-09 Phil Ezolt (Phillip.Ezolt@compaq.com)
+ *            Renamed modified smp_call_function to smp_call_function_on_cpu()
+ *            Created an function that conforms to the old calling convention
+ *            of smp_call_function().
+ *
+ *            This is helpful for DCPI.
+ *
+ */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/kernel_stat.h>
+#include <linux/module.h>
+#include <linux/sched/mm.h>
+#include <linux/mm.h>
+#include <linux/err.h>
+#include <linux/threads.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/irq.h>
+#include <linux/cache.h>
+#include <linux/profile.h>
+#include <linux/bitops.h>
+#include <linux/cpu.h>
+
+#include <asm/hwrpb.h>
+#include <asm/ptrace.h>
+#include <linux/atomic.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/mmu_context.h>
+#include <asm/tlbflush.h>
+
+#include "proto.h"
+#include "irq_impl.h"
+
+
+#define DEBUG_SMP 0
+#if DEBUG_SMP
+#define DBGS(args)	printk args
+#else
+#define DBGS(args)
+#endif
+
+/* A collection of per-processor data.  */
+struct cpuinfo_alpha cpu_data[NR_CPUS];
+EXPORT_SYMBOL(cpu_data);
+
+/* A collection of single bit ipi messages.  */
+static struct {
+	unsigned long bits ____cacheline_aligned;
+} ipi_data[NR_CPUS] __cacheline_aligned;
+
+enum ipi_message_type {
+	IPI_RESCHEDULE,
+	IPI_CALL_FUNC,
+	IPI_CPU_STOP,
+};
+
+/* Set to a secondary's cpuid when it comes online.  */
+static int smp_secondary_alive = 0;
+
+int smp_num_probed;		/* Internal processor count */
+int smp_num_cpus = 1;		/* Number that came online.  */
+EXPORT_SYMBOL(smp_num_cpus);
+
+/*
+ * Called by both boot and secondaries to move global data into
+ *  per-processor storage.
+ */
+static inline void __init
+smp_store_cpu_info(int cpuid)
+{
+	cpu_data[cpuid].loops_per_jiffy = loops_per_jiffy;
+	cpu_data[cpuid].last_asn = ASN_FIRST_VERSION;
+	cpu_data[cpuid].need_new_asn = 0;
+	cpu_data[cpuid].asn_lock = 0;
+}
+
+/*
+ * Ideally sets up per-cpu profiling hooks.  Doesn't do much now...
+ */
+static inline void __init
+smp_setup_percpu_timer(int cpuid)
+{
+	cpu_data[cpuid].prof_counter = 1;
+	cpu_data[cpuid].prof_multiplier = 1;
+}
+
+static void __init
+wait_boot_cpu_to_stop(int cpuid)
+{
+	unsigned long stop = jiffies + 10*HZ;
+
+	while (time_before(jiffies, stop)) {
+	        if (!smp_secondary_alive)
+			return;
+		barrier();
+	}
+
+	printk("wait_boot_cpu_to_stop: FAILED on CPU %d, hanging now\n", cpuid);
+	for (;;)
+		barrier();
+}
+
+/*
+ * Where secondaries begin a life of C.
+ */
+void __init
+smp_callin(void)
+{
+	int cpuid = hard_smp_processor_id();
+
+	if (cpu_online(cpuid)) {
+		printk("??, cpu 0x%x already present??\n", cpuid);
+		BUG();
+	}
+	set_cpu_online(cpuid, true);
+
+	/* Turn on machine checks.  */
+	wrmces(7);
+
+	/* Set trap vectors.  */
+	trap_init();
+
+	/* Set interrupt vector.  */
+	wrent(entInt, 0);
+
+	/* Get our local ticker going. */
+	smp_setup_percpu_timer(cpuid);
+	init_clockevent();
+
+	/* Call platform-specific callin, if specified */
+	if (alpha_mv.smp_callin)
+		alpha_mv.smp_callin();
+
+	/* All kernel threads share the same mm context.  */
+	mmgrab(&init_mm);
+	current->active_mm = &init_mm;
+
+	/* inform the notifiers about the new cpu */
+	notify_cpu_starting(cpuid);
+
+	/* Must have completely accurate bogos.  */
+	local_irq_enable();
+
+	/* Wait boot CPU to stop with irq enabled before running
+	   calibrate_delay. */
+	wait_boot_cpu_to_stop(cpuid);
+	mb();
+	calibrate_delay();
+
+	smp_store_cpu_info(cpuid);
+	/* Allow master to continue only after we written loops_per_jiffy.  */
+	wmb();
+	smp_secondary_alive = 1;
+
+	DBGS(("smp_callin: commencing CPU %d current %p active_mm %p\n",
+	      cpuid, current, current->active_mm));
+
+	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
+}
+
+/* Wait until hwrpb->txrdy is clear for cpu.  Return -1 on timeout.  */
+static int
+wait_for_txrdy (unsigned long cpumask)
+{
+	unsigned long timeout;
+
+	if (!(hwrpb->txrdy & cpumask))
+		return 0;
+
+	timeout = jiffies + 10*HZ;
+	while (time_before(jiffies, timeout)) {
+		if (!(hwrpb->txrdy & cpumask))
+			return 0;
+		udelay(10);
+		barrier();
+	}
+
+	return -1;
+}
+
+/*
+ * Send a message to a secondary's console.  "START" is one such
+ * interesting message.  ;-)
+ */
+static void
+send_secondary_console_msg(char *str, int cpuid)
+{
+	struct percpu_struct *cpu;
+	register char *cp1, *cp2;
+	unsigned long cpumask;
+	size_t len;
+
+	cpu = (struct percpu_struct *)
+		((char*)hwrpb
+		 + hwrpb->processor_offset
+		 + cpuid * hwrpb->processor_size);
+
+	cpumask = (1UL << cpuid);
+	if (wait_for_txrdy(cpumask))
+		goto timeout;
+
+	cp2 = str;
+	len = strlen(cp2);
+	*(unsigned int *)&cpu->ipc_buffer[0] = len;
+	cp1 = (char *) &cpu->ipc_buffer[1];
+	memcpy(cp1, cp2, len);
+
+	/* atomic test and set */
+	wmb();
+	set_bit(cpuid, &hwrpb->rxrdy);
+
+	if (wait_for_txrdy(cpumask))
+		goto timeout;
+	return;
+
+ timeout:
+	printk("Processor %x not ready\n", cpuid);
+}
+
+/*
+ * A secondary console wants to send a message.  Receive it.
+ */
+static void
+recv_secondary_console_msg(void)
+{
+	int mycpu, i, cnt;
+	unsigned long txrdy = hwrpb->txrdy;
+	char *cp1, *cp2, buf[80];
+	struct percpu_struct *cpu;
+
+	DBGS(("recv_secondary_console_msg: TXRDY 0x%lx.\n", txrdy));
+
+	mycpu = hard_smp_processor_id();
+
+	for (i = 0; i < NR_CPUS; i++) {
+		if (!(txrdy & (1UL << i)))
+			continue;
+
+		DBGS(("recv_secondary_console_msg: "
+		      "TXRDY contains CPU %d.\n", i));
+
+		cpu = (struct percpu_struct *)
+		  ((char*)hwrpb
+		   + hwrpb->processor_offset
+		   + i * hwrpb->processor_size);
+
+ 		DBGS(("recv_secondary_console_msg: on %d from %d"
+		      " HALT_REASON 0x%lx FLAGS 0x%lx\n",
+		      mycpu, i, cpu->halt_reason, cpu->flags));
+
+		cnt = cpu->ipc_buffer[0] >> 32;
+		if (cnt <= 0 || cnt >= 80)
+			strcpy(buf, "<<< BOGUS MSG >>>");
+		else {
+			cp1 = (char *) &cpu->ipc_buffer[1];
+			cp2 = buf;
+			memcpy(cp2, cp1, cnt);
+			cp2[cnt] = '\0';
+			
+			while ((cp2 = strchr(cp2, '\r')) != 0) {
+				*cp2 = ' ';
+				if (cp2[1] == '\n')
+					cp2[1] = ' ';
+			}
+		}
+
+		DBGS((KERN_INFO "recv_secondary_console_msg: on %d "
+		      "message is '%s'\n", mycpu, buf));
+	}
+
+	hwrpb->txrdy = 0;
+}
+
+/*
+ * Convince the console to have a secondary cpu begin execution.
+ */
+static int
+secondary_cpu_start(int cpuid, struct task_struct *idle)
+{
+	struct percpu_struct *cpu;
+	struct pcb_struct *hwpcb, *ipcb;
+	unsigned long timeout;
+	  
+	cpu = (struct percpu_struct *)
+		((char*)hwrpb
+		 + hwrpb->processor_offset
+		 + cpuid * hwrpb->processor_size);
+	hwpcb = (struct pcb_struct *) cpu->hwpcb;
+	ipcb = &task_thread_info(idle)->pcb;
+
+	/* Initialize the CPU's HWPCB to something just good enough for
+	   us to get started.  Immediately after starting, we'll swpctx
+	   to the target idle task's pcb.  Reuse the stack in the mean
+	   time.  Precalculate the target PCBB.  */
+	hwpcb->ksp = (unsigned long)ipcb + sizeof(union thread_union) - 16;
+	hwpcb->usp = 0;
+	hwpcb->ptbr = ipcb->ptbr;
+	hwpcb->pcc = 0;
+	hwpcb->asn = 0;
+	hwpcb->unique = virt_to_phys(ipcb);
+	hwpcb->flags = ipcb->flags;
+	hwpcb->res1 = hwpcb->res2 = 0;
+
+#if 0
+	DBGS(("KSP 0x%lx PTBR 0x%lx VPTBR 0x%lx UNIQUE 0x%lx\n",
+	      hwpcb->ksp, hwpcb->ptbr, hwrpb->vptb, hwpcb->unique));
+#endif
+	DBGS(("Starting secondary cpu %d: state 0x%lx pal_flags 0x%lx\n",
+	      cpuid, idle->state, ipcb->flags));
+
+	/* Setup HWRPB fields that SRM uses to activate secondary CPU */
+	hwrpb->CPU_restart = __smp_callin;
+	hwrpb->CPU_restart_data = (unsigned long) __smp_callin;
+
+	/* Recalculate and update the HWRPB checksum */
+	hwrpb_update_checksum(hwrpb);
+
+	/*
+	 * Send a "start" command to the specified processor.
+	 */
+
+	/* SRM III 3.4.1.3 */
+	cpu->flags |= 0x22;	/* turn on Context Valid and Restart Capable */
+	cpu->flags &= ~1;	/* turn off Bootstrap In Progress */
+	wmb();
+
+	send_secondary_console_msg("START\r\n", cpuid);
+
+	/* Wait 10 seconds for an ACK from the console.  */
+	timeout = jiffies + 10*HZ;
+	while (time_before(jiffies, timeout)) {
+		if (cpu->flags & 1)
+			goto started;
+		udelay(10);
+		barrier();
+	}
+	printk(KERN_ERR "SMP: Processor %d failed to start.\n", cpuid);
+	return -1;
+
+ started:
+	DBGS(("secondary_cpu_start: SUCCESS for CPU %d!!!\n", cpuid));
+	return 0;
+}
+
+/*
+ * Bring one cpu online.
+ */
+static int
+smp_boot_one_cpu(int cpuid, struct task_struct *idle)
+{
+	unsigned long timeout;
+
+	/* Signal the secondary to wait a moment.  */
+	smp_secondary_alive = -1;
+
+	/* Whirrr, whirrr, whirrrrrrrrr... */
+	if (secondary_cpu_start(cpuid, idle))
+		return -1;
+
+	/* Notify the secondary CPU it can run calibrate_delay.  */
+	mb();
+	smp_secondary_alive = 0;
+
+	/* We've been acked by the console; wait one second for
+	   the task to start up for real.  */
+	timeout = jiffies + 1*HZ;
+	while (time_before(jiffies, timeout)) {
+		if (smp_secondary_alive == 1)
+			goto alive;
+		udelay(10);
+		barrier();
+	}
+
+	/* We failed to boot the CPU.  */
+
+	printk(KERN_ERR "SMP: Processor %d is stuck.\n", cpuid);
+	return -1;
+
+ alive:
+	/* Another "Red Snapper". */
+	return 0;
+}
+
+/*
+ * Called from setup_arch.  Detect an SMP system and which processors
+ * are present.
+ */
+void __init
+setup_smp(void)
+{
+	struct percpu_struct *cpubase, *cpu;
+	unsigned long i;
+
+	if (boot_cpuid != 0) {
+		printk(KERN_WARNING "SMP: Booting off cpu %d instead of 0?\n",
+		       boot_cpuid);
+	}
+
+	if (hwrpb->nr_processors > 1) {
+		int boot_cpu_palrev;
+
+		DBGS(("setup_smp: nr_processors %ld\n",
+		      hwrpb->nr_processors));
+
+		cpubase = (struct percpu_struct *)
+			((char*)hwrpb + hwrpb->processor_offset);
+		boot_cpu_palrev = cpubase->pal_revision;
+
+		for (i = 0; i < hwrpb->nr_processors; i++) {
+			cpu = (struct percpu_struct *)
+				((char *)cpubase + i*hwrpb->processor_size);
+			if ((cpu->flags & 0x1cc) == 0x1cc) {
+				smp_num_probed++;
+				set_cpu_possible(i, true);
+				set_cpu_present(i, true);
+				cpu->pal_revision = boot_cpu_palrev;
+			}
+
+			DBGS(("setup_smp: CPU %d: flags 0x%lx type 0x%lx\n",
+			      i, cpu->flags, cpu->type));
+			DBGS(("setup_smp: CPU %d: PAL rev 0x%lx\n",
+			      i, cpu->pal_revision));
+		}
+	} else {
+		smp_num_probed = 1;
+	}
+
+	printk(KERN_INFO "SMP: %d CPUs probed -- cpu_present_mask = %lx\n",
+	       smp_num_probed, cpumask_bits(cpu_present_mask)[0]);
+}
+
+/*
+ * Called by smp_init prepare the secondaries
+ */
+void __init
+smp_prepare_cpus(unsigned int max_cpus)
+{
+	/* Take care of some initial bookkeeping.  */
+	memset(ipi_data, 0, sizeof(ipi_data));
+
+	current_thread_info()->cpu = boot_cpuid;
+
+	smp_store_cpu_info(boot_cpuid);
+	smp_setup_percpu_timer(boot_cpuid);
+
+	/* Nothing to do on a UP box, or when told not to.  */
+	if (smp_num_probed == 1 || max_cpus == 0) {
+		init_cpu_possible(cpumask_of(boot_cpuid));
+		init_cpu_present(cpumask_of(boot_cpuid));
+		printk(KERN_INFO "SMP mode deactivated.\n");
+		return;
+	}
+
+	printk(KERN_INFO "SMP starting up secondaries.\n");
+
+	smp_num_cpus = smp_num_probed;
+}
+
+void
+smp_prepare_boot_cpu(void)
+{
+}
+
+int
+__cpu_up(unsigned int cpu, struct task_struct *tidle)
+{
+	smp_boot_one_cpu(cpu, tidle);
+
+	return cpu_online(cpu) ? 0 : -ENOSYS;
+}
+
+void __init
+smp_cpus_done(unsigned int max_cpus)
+{
+	int cpu;
+	unsigned long bogosum = 0;
+
+	for(cpu = 0; cpu < NR_CPUS; cpu++) 
+		if (cpu_online(cpu))
+			bogosum += cpu_data[cpu].loops_per_jiffy;
+	
+	printk(KERN_INFO "SMP: Total of %d processors activated "
+	       "(%lu.%02lu BogoMIPS).\n",
+	       num_online_cpus(), 
+	       (bogosum + 2500) / (500000/HZ),
+	       ((bogosum + 2500) / (5000/HZ)) % 100);
+}
+
+static void
+send_ipi_message(const struct cpumask *to_whom, enum ipi_message_type operation)
+{
+	int i;
+
+	mb();
+	for_each_cpu(i, to_whom)
+		set_bit(operation, &ipi_data[i].bits);
+
+	mb();
+	for_each_cpu(i, to_whom)
+		wripir(i);
+}
+
+void
+handle_ipi(struct pt_regs *regs)
+{
+	int this_cpu = smp_processor_id();
+	unsigned long *pending_ipis = &ipi_data[this_cpu].bits;
+	unsigned long ops;
+
+#if 0
+	DBGS(("handle_ipi: on CPU %d ops 0x%lx PC 0x%lx\n",
+	      this_cpu, *pending_ipis, regs->pc));
+#endif
+
+	mb();	/* Order interrupt and bit testing. */
+	while ((ops = xchg(pending_ipis, 0)) != 0) {
+	  mb();	/* Order bit clearing and data access. */
+	  do {
+		unsigned long which;
+
+		which = ops & -ops;
+		ops &= ~which;
+		which = __ffs(which);
+
+		switch (which) {
+		case IPI_RESCHEDULE:
+			scheduler_ipi();
+			break;
+
+		case IPI_CALL_FUNC:
+			generic_smp_call_function_interrupt();
+			break;
+
+		case IPI_CPU_STOP:
+			halt();
+
+		default:
+			printk(KERN_CRIT "Unknown IPI on CPU %d: %lu\n",
+			       this_cpu, which);
+			break;
+		}
+	  } while (ops);
+
+	  mb();	/* Order data access and bit testing. */
+	}
+
+	cpu_data[this_cpu].ipi_count++;
+
+	if (hwrpb->txrdy)
+		recv_secondary_console_msg();
+}
+
+void
+smp_send_reschedule(int cpu)
+{
+#ifdef DEBUG_IPI_MSG
+	if (cpu == hard_smp_processor_id())
+		printk(KERN_WARNING
+		       "smp_send_reschedule: Sending IPI to self.\n");
+#endif
+	send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
+}
+
+void
+smp_send_stop(void)
+{
+	cpumask_t to_whom;
+	cpumask_copy(&to_whom, cpu_online_mask);
+	cpumask_clear_cpu(smp_processor_id(), &to_whom);
+#ifdef DEBUG_IPI_MSG
+	if (hard_smp_processor_id() != boot_cpu_id)
+		printk(KERN_WARNING "smp_send_stop: Not on boot cpu.\n");
+#endif
+	send_ipi_message(&to_whom, IPI_CPU_STOP);
+}
+
+void arch_send_call_function_ipi_mask(const struct cpumask *mask)
+{
+	send_ipi_message(mask, IPI_CALL_FUNC);
+}
+
+void arch_send_call_function_single_ipi(int cpu)
+{
+	send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC);
+}
+
+static void
+ipi_imb(void *ignored)
+{
+	imb();
+}
+
+void
+smp_imb(void)
+{
+	/* Must wait other processors to flush their icache before continue. */
+	on_each_cpu(ipi_imb, NULL, 1);
+}
+EXPORT_SYMBOL(smp_imb);
+
+static void
+ipi_flush_tlb_all(void *ignored)
+{
+	tbia();
+}
+
+void
+flush_tlb_all(void)
+{
+	/* Although we don't have any data to pass, we do want to
+	   synchronize with the other processors.  */
+	on_each_cpu(ipi_flush_tlb_all, NULL, 1);
+}
+
+#define asn_locked() (cpu_data[smp_processor_id()].asn_lock)
+
+static void
+ipi_flush_tlb_mm(void *x)
+{
+	struct mm_struct *mm = (struct mm_struct *) x;
+	if (mm == current->active_mm && !asn_locked())
+		flush_tlb_current(mm);
+	else
+		flush_tlb_other(mm);
+}
+
+void
+flush_tlb_mm(struct mm_struct *mm)
+{
+	preempt_disable();
+
+	if (mm == current->active_mm) {
+		flush_tlb_current(mm);
+		if (atomic_read(&mm->mm_users) <= 1) {
+			int cpu, this_cpu = smp_processor_id();
+			for (cpu = 0; cpu < NR_CPUS; cpu++) {
+				if (!cpu_online(cpu) || cpu == this_cpu)
+					continue;
+				if (mm->context[cpu])
+					mm->context[cpu] = 0;
+			}
+			preempt_enable();
+			return;
+		}
+	}
+
+	smp_call_function(ipi_flush_tlb_mm, mm, 1);
+
+	preempt_enable();
+}
+EXPORT_SYMBOL(flush_tlb_mm);
+
+struct flush_tlb_page_struct {
+	struct vm_area_struct *vma;
+	struct mm_struct *mm;
+	unsigned long addr;
+};
+
+static void
+ipi_flush_tlb_page(void *x)
+{
+	struct flush_tlb_page_struct *data = (struct flush_tlb_page_struct *)x;
+	struct mm_struct * mm = data->mm;
+
+	if (mm == current->active_mm && !asn_locked())
+		flush_tlb_current_page(mm, data->vma, data->addr);
+	else
+		flush_tlb_other(mm);
+}
+
+void
+flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
+{
+	struct flush_tlb_page_struct data;
+	struct mm_struct *mm = vma->vm_mm;
+
+	preempt_disable();
+
+	if (mm == current->active_mm) {
+		flush_tlb_current_page(mm, vma, addr);
+		if (atomic_read(&mm->mm_users) <= 1) {
+			int cpu, this_cpu = smp_processor_id();
+			for (cpu = 0; cpu < NR_CPUS; cpu++) {
+				if (!cpu_online(cpu) || cpu == this_cpu)
+					continue;
+				if (mm->context[cpu])
+					mm->context[cpu] = 0;
+			}
+			preempt_enable();
+			return;
+		}
+	}
+
+	data.vma = vma;
+	data.mm = mm;
+	data.addr = addr;
+
+	smp_call_function(ipi_flush_tlb_page, &data, 1);
+
+	preempt_enable();
+}
+EXPORT_SYMBOL(flush_tlb_page);
+
+void
+flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
+{
+	/* On the Alpha we always flush the whole user tlb.  */
+	flush_tlb_mm(vma->vm_mm);
+}
+EXPORT_SYMBOL(flush_tlb_range);
+
+static void
+ipi_flush_icache_page(void *x)
+{
+	struct mm_struct *mm = (struct mm_struct *) x;
+	if (mm == current->active_mm && !asn_locked())
+		__load_new_mm_context(mm);
+	else
+		flush_tlb_other(mm);
+}
+
+void
+flush_icache_user_page(struct vm_area_struct *vma, struct page *page,
+			unsigned long addr, int len)
+{
+	struct mm_struct *mm = vma->vm_mm;
+
+	if ((vma->vm_flags & VM_EXEC) == 0)
+		return;
+
+	preempt_disable();
+
+	if (mm == current->active_mm) {
+		__load_new_mm_context(mm);
+		if (atomic_read(&mm->mm_users) <= 1) {
+			int cpu, this_cpu = smp_processor_id();
+			for (cpu = 0; cpu < NR_CPUS; cpu++) {
+				if (!cpu_online(cpu) || cpu == this_cpu)
+					continue;
+				if (mm->context[cpu])
+					mm->context[cpu] = 0;
+			}
+			preempt_enable();
+			return;
+		}
+	}
+
+	smp_call_function(ipi_flush_icache_page, mm, 1);
+
+	preempt_enable();
+}