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authorRichard Kuo <rkuo@codeaurora.org>2011-10-31 18:46:34 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2011-11-01 07:34:20 -0700
commit43afdf508386342d714f6911c1976f934b520cb0 (patch)
treede4acc7cca0990d28be24fa4f6779ef4e31945e5 /arch/hexagon/kernel
parentcf9750bae262dba73a6abaecd2ec3731ba7aef9c (diff)
downloadvexpress-lsk-43afdf508386342d714f6911c1976f934b520cb0.tar.gz
Hexagon: Add SMP support
Signed-off-by: Richard Kuo <rkuo@codeaurora.org> Signed-off-by: Linas Vepstas <linas@codeaurora.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/hexagon/kernel')
-rw-r--r--arch/hexagon/kernel/smp.c276
-rw-r--r--arch/hexagon/kernel/topology.c52
2 files changed, 328 insertions, 0 deletions
diff --git a/arch/hexagon/kernel/smp.c b/arch/hexagon/kernel/smp.c
new file mode 100644
index 00000000000..c871a2cffae
--- /dev/null
+++ b/arch/hexagon/kernel/smp.c
@@ -0,0 +1,276 @@
+/*
+ * SMP support for Hexagon
+ *
+ * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/percpu.h>
+#include <linux/sched.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
+
+#include <asm/system.h> /* xchg */
+#include <asm/time.h> /* timer_interrupt */
+#include <asm/hexagon_vm.h>
+
+#define BASE_IPI_IRQ 26
+
+/*
+ * cpu_possible_map needs to be filled out prior to setup_per_cpu_areas
+ * (which is prior to any of our smp_prepare_cpu crap), in order to set
+ * up the... per_cpu areas.
+ */
+
+struct ipi_data {
+ unsigned long bits;
+};
+
+static DEFINE_PER_CPU(struct ipi_data, ipi_data);
+
+static inline void __handle_ipi(unsigned long *ops, struct ipi_data *ipi,
+ int cpu)
+{
+ unsigned long msg = 0;
+ do {
+ msg = find_next_bit(ops, BITS_PER_LONG, msg+1);
+
+ switch (msg) {
+
+ case IPI_TIMER:
+ ipi_timer();
+ break;
+
+ case IPI_CALL_FUNC:
+ generic_smp_call_function_interrupt();
+ break;
+
+ case IPI_CALL_FUNC_SINGLE:
+ generic_smp_call_function_single_interrupt();
+ break;
+
+ case IPI_CPU_STOP:
+ /*
+ * call vmstop()
+ */
+ __vmstop();
+ break;
+
+ case IPI_RESCHEDULE:
+ scheduler_ipi();
+ break;
+ }
+ } while (msg < BITS_PER_LONG);
+}
+
+/* Used for IPI call from other CPU's to unmask int */
+void smp_vm_unmask_irq(void *info)
+{
+ __vmintop_locen((long) info);
+}
+
+
+/*
+ * This is based on Alpha's IPI stuff.
+ * Supposed to take (int, void*) as args now.
+ * Specifically, first arg is irq, second is the irq_desc.
+ */
+
+irqreturn_t handle_ipi(int irq, void *desc)
+{
+ int cpu = smp_processor_id();
+ struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
+ unsigned long ops;
+
+ while ((ops = xchg(&ipi->bits, 0)) != 0)
+ __handle_ipi(&ops, ipi, cpu);
+ return IRQ_HANDLED;
+}
+
+void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg)
+{
+ unsigned long flags;
+ unsigned long cpu;
+ unsigned long retval;
+
+ local_irq_save(flags);
+
+ for_each_cpu(cpu, cpumask) {
+ struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
+
+ set_bit(msg, &ipi->bits);
+ /* Possible barrier here */
+ retval = __vmintop_post(BASE_IPI_IRQ+cpu);
+
+ if (retval != 0) {
+ printk(KERN_ERR "interrupt %ld not configured?\n",
+ BASE_IPI_IRQ+cpu);
+ }
+ }
+
+ local_irq_restore(flags);
+}
+
+static struct irqaction ipi_intdesc = {
+ .handler = handle_ipi,
+ .flags = IRQF_TRIGGER_RISING,
+ .name = "ipi_handler"
+};
+
+void __init smp_prepare_boot_cpu(void)
+{
+}
+
+/*
+ * interrupts should already be disabled from the VM
+ * SP should already be correct; need to set THREADINFO_REG
+ * to point to current thread info
+ */
+
+void __cpuinit start_secondary(void)
+{
+ unsigned int cpu;
+ unsigned long thread_ptr;
+
+ /* Calculate thread_info pointer from stack pointer */
+ __asm__ __volatile__(
+ "%0 = SP;\n"
+ : "=r" (thread_ptr)
+ );
+
+ thread_ptr = thread_ptr & ~(THREAD_SIZE-1);
+
+ __asm__ __volatile__(
+ QUOTED_THREADINFO_REG " = %0;\n"
+ :
+ : "r" (thread_ptr)
+ );
+
+ /* Set the memory struct */
+ atomic_inc(&init_mm.mm_count);
+ current->active_mm = &init_mm;
+
+ cpu = smp_processor_id();
+
+ setup_irq(BASE_IPI_IRQ + cpu, &ipi_intdesc);
+
+ /* Register the clock_event dummy */
+ setup_percpu_clockdev();
+
+ printk(KERN_INFO "%s cpu %d\n", __func__, current_thread_info()->cpu);
+
+ set_cpu_online(cpu, true);
+ while (!cpumask_test_cpu(cpu, cpu_active_mask))
+ cpu_relax();
+ local_irq_enable();
+
+ cpu_idle();
+}
+
+
+/*
+ * called once for each present cpu
+ * apparently starts up the CPU and then
+ * maintains control until "cpu_online(cpu)" is set.
+ */
+
+int __cpuinit __cpu_up(unsigned int cpu)
+{
+ struct task_struct *idle;
+ struct thread_info *thread;
+ void *stack_start;
+
+ /* Create new init task for the CPU */
+ idle = fork_idle(cpu);
+ if (IS_ERR(idle))
+ panic(KERN_ERR "fork_idle failed\n");
+
+ thread = (struct thread_info *)idle->stack;
+ thread->cpu = cpu;
+
+ /* Boot to the head. */
+ stack_start = ((void *) thread) + THREAD_SIZE;
+ __vmstart(start_secondary, stack_start);
+
+ while (!cpu_isset(cpu, cpu_online_map))
+ barrier();
+
+ return 0;
+}
+
+void __init smp_cpus_done(unsigned int max_cpus)
+{
+}
+
+void __init smp_prepare_cpus(unsigned int max_cpus)
+{
+ int i;
+
+ /*
+ * should eventually have some sort of machine
+ * descriptor that has this stuff
+ */
+
+ /* Right now, let's just fake it. */
+ for (i = 0; i < max_cpus; i++)
+ cpu_set(i, cpu_present_map);
+
+ /* Also need to register the interrupts for IPI */
+ if (max_cpus > 1)
+ setup_irq(BASE_IPI_IRQ, &ipi_intdesc);
+}
+
+void smp_send_reschedule(int cpu)
+{
+ send_ipi(cpumask_of(cpu), IPI_RESCHEDULE);
+}
+
+void smp_send_stop(void)
+{
+ struct cpumask targets;
+ cpumask_copy(&targets, cpu_online_mask);
+ cpumask_clear_cpu(smp_processor_id(), &targets);
+ send_ipi(&targets, IPI_CPU_STOP);
+}
+
+void arch_send_call_function_single_ipi(int cpu)
+{
+ send_ipi(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
+}
+
+void arch_send_call_function_ipi_mask(const struct cpumask *mask)
+{
+ send_ipi(mask, IPI_CALL_FUNC);
+}
+
+int setup_profiling_timer(unsigned int multiplier)
+{
+ return -EINVAL;
+}
+
+void smp_start_cpus(void)
+{
+ int i;
+
+ for (i = 0; i < NR_CPUS; i++)
+ cpu_set(i, cpu_possible_map);
+}
diff --git a/arch/hexagon/kernel/topology.c b/arch/hexagon/kernel/topology.c
new file mode 100644
index 00000000000..ba447518443
--- /dev/null
+++ b/arch/hexagon/kernel/topology.c
@@ -0,0 +1,52 @@
+/*
+ * CPU topology for Hexagon
+ *
+ * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#include <linux/cpu.h>
+#include <linux/cpumask.h>
+#include <linux/init.h>
+#include <linux/node.h>
+#include <linux/nodemask.h>
+#include <linux/percpu.h>
+
+/* Swiped from MIPS. */
+
+static DEFINE_PER_CPU(struct cpu, cpu_devices);
+
+static int __init topology_init(void)
+{
+ int i, ret;
+
+ for_each_present_cpu(i) {
+
+ /*
+ * register_cpu takes a per_cpu pointer and
+ * just points it at another per_cpu struct...
+ */
+
+ ret = register_cpu(&per_cpu(cpu_devices, i), i);
+ if (ret)
+ printk(KERN_WARNING "topology_init: register_cpu %d "
+ "failed (%d)\n", i, ret);
+ }
+
+ return 0;
+}
+
+subsys_initcall(topology_init);