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-rw-r--r--arch/alpha/kernel/smp.c762
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();
+}