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-rw-r--r--arch/arm/kernel/head.S44
-rw-r--r--arch/arm/kernel/smp.c107
-rw-r--r--arch/arm/mach-integrator/Makefile1
-rw-r--r--arch/arm/mach-integrator/core.c20
-rw-r--r--arch/arm/mach-integrator/headsmp.S37
-rw-r--r--arch/arm/mach-integrator/leds.c4
-rw-r--r--arch/arm/mach-integrator/platsmp.c192
-rw-r--r--include/asm-arm/arch-integrator/smp.h19
-rw-r--r--include/asm-arm/smp.h14
9 files changed, 436 insertions, 2 deletions
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 4733877296d..bd4823c7464 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -2,6 +2,8 @@
* linux/arch/arm/kernel/head.S
*
* Copyright (C) 1994-2002 Russell King
+ * Copyright (c) 2003 ARM Limited
+ * 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 as
@@ -165,6 +167,48 @@ __mmap_switched:
stmia r6, {r0, r4} @ Save control register values
b start_kernel
+#if defined(CONFIG_SMP)
+ .type secondary_startup, #function
+ENTRY(secondary_startup)
+ /*
+ * Common entry point for secondary CPUs.
+ *
+ * Ensure that we're in SVC mode, and IRQs are disabled. Lookup
+ * the processor type - there is no need to check the machine type
+ * as it has already been validated by the primary processor.
+ */
+ msr cpsr_c, #PSR_F_BIT | PSR_I_BIT | MODE_SVC
+ bl __lookup_processor_type
+ movs r10, r5 @ invalid processor?
+ moveq r0, #'p' @ yes, error 'p'
+ beq __error
+
+ /*
+ * Use the page tables supplied from __cpu_up.
+ */
+ adr r4, __secondary_data
+ ldmia r4, {r5, r6, r13} @ address to jump to after
+ sub r4, r4, r5 @ mmu has been enabled
+ ldr r4, [r6, r4] @ get secondary_data.pgdir
+ adr lr, __enable_mmu @ return address
+ add pc, r10, #12 @ initialise processor
+ @ (return control reg)
+
+ /*
+ * r6 = &secondary_data
+ */
+ENTRY(__secondary_switched)
+ ldr sp, [r6, #4] @ get secondary_data.stack
+ mov fp, #0
+ b secondary_start_kernel
+
+ .type __secondary_data, %object
+__secondary_data:
+ .long .
+ .long secondary_data
+ .long __secondary_switched
+#endif /* defined(CONFIG_SMP) */
+
/*
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index ecc8c333240..45ed036336e 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -24,6 +24,9 @@
#include <asm/atomic.h>
#include <asm/cacheflush.h>
#include <asm/cpu.h>
+#include <asm/mmu_context.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
#include <asm/processor.h>
#include <asm/tlbflush.h>
#include <asm/ptrace.h>
@@ -37,6 +40,13 @@ cpumask_t cpu_present_mask;
cpumask_t cpu_online_map;
/*
+ * as from 2.5, kernels no longer have an init_tasks structure
+ * so we need some other way of telling a new secondary core
+ * where to place its SVC stack
+ */
+struct secondary_data secondary_data;
+
+/*
* structures for inter-processor calls
* - A collection of single bit ipi messages.
*/
@@ -71,6 +81,8 @@ static DEFINE_SPINLOCK(smp_call_function_lock);
int __init __cpu_up(unsigned int cpu)
{
struct task_struct *idle;
+ pgd_t *pgd;
+ pmd_t *pmd;
int ret;
/*
@@ -84,9 +96,54 @@ int __init __cpu_up(unsigned int cpu)
}
/*
+ * Allocate initial page tables to allow the new CPU to
+ * enable the MMU safely. This essentially means a set
+ * of our "standard" page tables, with the addition of
+ * a 1:1 mapping for the physical address of the kernel.
+ */
+ pgd = pgd_alloc(&init_mm);
+ pmd = pmd_offset(pgd, PHYS_OFFSET);
+ *pmd = __pmd((PHYS_OFFSET & PGDIR_MASK) |
+ PMD_TYPE_SECT | PMD_SECT_AP_WRITE);
+
+ /*
+ * We need to tell the secondary core where to find
+ * its stack and the page tables.
+ */
+ secondary_data.stack = (void *)idle->thread_info + THREAD_SIZE - 8;
+ secondary_data.pgdir = virt_to_phys(pgd);
+ wmb();
+
+ /*
* Now bring the CPU into our world.
*/
ret = boot_secondary(cpu, idle);
+ if (ret == 0) {
+ unsigned long timeout;
+
+ /*
+ * CPU was successfully started, wait for it
+ * to come online or time out.
+ */
+ timeout = jiffies + HZ;
+ while (time_before(jiffies, timeout)) {
+ if (cpu_online(cpu))
+ break;
+
+ udelay(10);
+ barrier();
+ }
+
+ if (!cpu_online(cpu))
+ ret = -EIO;
+ }
+
+ secondary_data.stack = 0;
+ secondary_data.pgdir = 0;
+
+ *pmd_offset(pgd, PHYS_OFFSET) = __pmd(0);
+ pgd_free(pgd);
+
if (ret) {
printk(KERN_CRIT "cpu_up: processor %d failed to boot\n", cpu);
/*
@@ -98,6 +155,56 @@ int __init __cpu_up(unsigned int cpu)
}
/*
+ * This is the secondary CPU boot entry. We're using this CPUs
+ * idle thread stack, but a set of temporary page tables.
+ */
+asmlinkage void __init secondary_start_kernel(void)
+{
+ struct mm_struct *mm = &init_mm;
+ unsigned int cpu = smp_processor_id();
+
+ printk("CPU%u: Booted secondary processor\n", cpu);
+
+ /*
+ * All kernel threads share the same mm context; grab a
+ * reference and switch to it.
+ */
+ atomic_inc(&mm->mm_users);
+ atomic_inc(&mm->mm_count);
+ current->active_mm = mm;
+ cpu_set(cpu, mm->cpu_vm_mask);
+ cpu_switch_mm(mm->pgd, mm);
+ enter_lazy_tlb(mm, current);
+
+ cpu_init();
+
+ /*
+ * Give the platform a chance to do its own initialisation.
+ */
+ platform_secondary_init(cpu);
+
+ /*
+ * Enable local interrupts.
+ */
+ local_irq_enable();
+ local_fiq_enable();
+
+ calibrate_delay();
+
+ smp_store_cpu_info(cpu);
+
+ /*
+ * OK, now it's safe to let the boot CPU continue
+ */
+ cpu_set(cpu, cpu_online_map);
+
+ /*
+ * OK, it's off to the idle thread for us
+ */
+ cpu_idle();
+}
+
+/*
* Called by both boot and secondaries to move global data into
* per-processor storage.
*/
diff --git a/arch/arm/mach-integrator/Makefile b/arch/arm/mach-integrator/Makefile
index 158daaf9e3b..ebb255bdce8 100644
--- a/arch/arm/mach-integrator/Makefile
+++ b/arch/arm/mach-integrator/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_LEDS) += leds.o
obj-$(CONFIG_PCI) += pci_v3.o pci.o
obj-$(CONFIG_CPU_FREQ_INTEGRATOR) += cpu.o
obj-$(CONFIG_INTEGRATOR_IMPD1) += impd1.o
+obj-$(CONFIG_SMP) += platsmp.o headsmp.o
diff --git a/arch/arm/mach-integrator/core.c b/arch/arm/mach-integrator/core.c
index bd17b515431..d302f0405fd 100644
--- a/arch/arm/mach-integrator/core.c
+++ b/arch/arm/mach-integrator/core.c
@@ -14,6 +14,7 @@
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
+#include <linux/smp.h>
#include <asm/hardware.h>
#include <asm/irq.h>
@@ -221,7 +222,24 @@ integrator_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
*/
timer1->TimerClear = 1;
- timer_tick(regs);
+ /*
+ * the clock tick routines are only processed on the
+ * primary CPU
+ */
+ if (hard_smp_processor_id() == 0) {
+ nmi_tick();
+ timer_tick(regs);
+#ifdef CONFIG_SMP
+ smp_send_timer();
+#endif
+ }
+
+#ifdef CONFIG_SMP
+ /*
+ * this is the ARM equivalent of the APIC timer interrupt
+ */
+ update_process_times(user_mode(regs));
+#endif /* CONFIG_SMP */
write_sequnlock(&xtime_lock);
diff --git a/arch/arm/mach-integrator/headsmp.S b/arch/arm/mach-integrator/headsmp.S
new file mode 100644
index 00000000000..ceaa88e30d7
--- /dev/null
+++ b/arch/arm/mach-integrator/headsmp.S
@@ -0,0 +1,37 @@
+/*
+ * linux/arch/arm/mach-integrator/headsmp.S
+ *
+ * Copyright (c) 2003 ARM Limited
+ * 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 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/linkage.h>
+#include <linux/init.h>
+
+ __INIT
+
+/*
+ * Integrator specific entry point for secondary CPUs. This provides
+ * a "holding pen" into which all secondary cores are held until we're
+ * ready for them to initialise.
+ */
+ENTRY(integrator_secondary_startup)
+ adr r4, 1f
+ ldmia r4, {r5, r6}
+ sub r4, r4, r5
+ ldr r6, [r6, r4]
+pen: ldr r7, [r6]
+ cmp r7, r0
+ bne pen
+
+ /*
+ * we've been released from the holding pen: secondary_stack
+ * should now contain the SVC stack for this core
+ */
+ b secondary_startup
+
+1: .long .
+ .long phys_pen_release
diff --git a/arch/arm/mach-integrator/leds.c b/arch/arm/mach-integrator/leds.c
index d2c0ab21150..f1436e683b4 100644
--- a/arch/arm/mach-integrator/leds.c
+++ b/arch/arm/mach-integrator/leds.c
@@ -22,6 +22,8 @@
*/
#include <linux/kernel.h>
#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
#include <asm/hardware.h>
#include <asm/io.h>
@@ -85,4 +87,4 @@ static int __init leds_init(void)
return 0;
}
-__initcall(leds_init);
+core_initcall(leds_init);
diff --git a/arch/arm/mach-integrator/platsmp.c b/arch/arm/mach-integrator/platsmp.c
new file mode 100644
index 00000000000..ead15dfcb53
--- /dev/null
+++ b/arch/arm/mach-integrator/platsmp.c
@@ -0,0 +1,192 @@
+/*
+ * linux/arch/arm/mach-cintegrator/platsmp.c
+ *
+ * Copyright (C) 2002 ARM Ltd.
+ * 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 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+
+#include <asm/atomic.h>
+#include <asm/delay.h>
+#include <asm/mmu_context.h>
+#include <asm/procinfo.h>
+#include <asm/ptrace.h>
+#include <asm/smp.h>
+
+extern void integrator_secondary_startup(void);
+
+/*
+ * control for which core is the next to come out of the secondary
+ * boot "holding pen"
+ */
+volatile int __initdata pen_release = -1;
+unsigned long __initdata phys_pen_release = 0;
+
+static DEFINE_SPINLOCK(boot_lock);
+
+void __init platform_secondary_init(unsigned int cpu)
+{
+ /*
+ * the primary core may have used a "cross call" soft interrupt
+ * to get this processor out of WFI in the BootMonitor - make
+ * sure that we are no longer being sent this soft interrupt
+ */
+ smp_cross_call_done(cpumask_of_cpu(cpu));
+
+ /*
+ * if any interrupts are already enabled for the primary
+ * core (e.g. timer irq), then they will not have been enabled
+ * for us: do so
+ */
+ secondary_scan_irqs();
+
+ /*
+ * let the primary processor know we're out of the
+ * pen, then head off into the C entry point
+ */
+ pen_release = -1;
+
+ /*
+ * Synchronise with the boot thread.
+ */
+ spin_lock(&boot_lock);
+ spin_unlock(&boot_lock);
+}
+
+int __init boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+ unsigned long timeout;
+
+ /*
+ * set synchronisation state between this boot processor
+ * and the secondary one
+ */
+ spin_lock(&boot_lock);
+
+ /*
+ * The secondary processor is waiting to be released from
+ * the holding pen - release it, then wait for it to flag
+ * that it has been released by resetting pen_release.
+ *
+ * Note that "pen_release" is the hardware CPU ID, whereas
+ * "cpu" is Linux's internal ID.
+ */
+ pen_release = cpu;
+
+ /*
+ * XXX
+ *
+ * This is a later addition to the booting protocol: the
+ * bootMonitor now puts secondary cores into WFI, so
+ * poke_milo() no longer gets the cores moving; we need
+ * to send a soft interrupt to wake the secondary core.
+ * Use smp_cross_call() for this, since there's little
+ * point duplicating the code here
+ */
+ smp_cross_call(cpumask_of_cpu(cpu));
+
+ timeout = jiffies + (1 * HZ);
+ while (time_before(jiffies, timeout)) {
+ if (pen_release == -1)
+ break;
+
+ udelay(10);
+ }
+
+ /*
+ * now the secondary core is starting up let it run its
+ * calibrations, then wait for it to finish
+ */
+ spin_unlock(&boot_lock);
+
+ return pen_release != -1 ? -ENOSYS : 0;
+}
+
+static void __init poke_milo(void)
+{
+ extern void secondary_startup(void);
+
+ /* nobody is to be released from the pen yet */
+ pen_release = -1;
+
+ phys_pen_release = virt_to_phys(&pen_release);
+
+ /*
+ * write the address of secondary startup into the system-wide
+ * flags register, then clear the bottom two bits, which is what
+ * BootMonitor is waiting for
+ */
+#if 1
+#define CINTEGRATOR_HDR_FLAGSS_OFFSET 0x30
+ __raw_writel(virt_to_phys(integrator_secondary_startup),
+ (IO_ADDRESS(INTEGRATOR_HDR_BASE) +
+ CINTEGRATOR_HDR_FLAGSS_OFFSET));
+#define CINTEGRATOR_HDR_FLAGSC_OFFSET 0x34
+ __raw_writel(3,
+ (IO_ADDRESS(INTEGRATOR_HDR_BASE) +
+ CINTEGRATOR_HDR_FLAGSC_OFFSET));
+#endif
+
+ mb();
+}
+
+void __init smp_prepare_cpus(unsigned int max_cpus)
+{
+ unsigned int ncores = get_core_count();
+ unsigned int cpu = smp_processor_id();
+ int i;
+
+ /* sanity check */
+ if (ncores == 0) {
+ printk(KERN_ERR
+ "Integrator/CP: strange CM count of 0? Default to 1\n");
+
+ ncores = 1;
+ }
+
+ if (ncores > NR_CPUS) {
+ printk(KERN_WARNING
+ "Integrator/CP: no. of cores (%d) greater than configured "
+ "maximum of %d - clipping\n",
+ ncores, NR_CPUS);
+ ncores = NR_CPUS;
+ }
+
+ /*
+ * start with some more config for the Boot CPU, now that
+ * the world is a bit more alive (which was not the case
+ * when smp_prepare_boot_cpu() was called)
+ */
+ smp_store_cpu_info(cpu);
+
+ /*
+ * are we trying to boot more cores than exist?
+ */
+ if (max_cpus > ncores)
+ max_cpus = ncores;
+
+ /*
+ * Initialise the present mask - this tells us which CPUs should
+ * be present.
+ */
+ for (i = 0; i < max_cpus; i++) {
+ cpu_set(i, cpu_present_mask);
+ }
+
+ /*
+ * Do we need any more CPUs? If so, then let them know where
+ * to start. Note that, on modern versions of MILO, the "poke"
+ * doesn't actually do anything until each individual core is
+ * sent a soft interrupt to get it out of WFI
+ */
+ if (max_cpus > 1)
+ poke_milo();
+}
diff --git a/include/asm-arm/arch-integrator/smp.h b/include/asm-arm/arch-integrator/smp.h
new file mode 100644
index 00000000000..0ec7093f7c3
--- /dev/null
+++ b/include/asm-arm/arch-integrator/smp.h
@@ -0,0 +1,19 @@
+#ifndef ASMARM_ARCH_SMP_H
+#define ASMARM_ARCH_SMP_H
+
+#include <linux/config.h>
+
+#include <asm/arch/hardware.h>
+#include <asm/io.h>
+
+#define hard_smp_processor_id() \
+ ({ \
+ unsigned int cpunum; \
+ __asm__("mrc p15, 0, %0, c0, c0, 5" \
+ : "=r" (cpunum)); \
+ cpunum &= 0x0F; \
+ })
+
+extern void secondary_scan_irqs(void);
+
+#endif
diff --git a/include/asm-arm/smp.h b/include/asm-arm/smp.h
index f21fd8f6bcd..bd44f894690 100644
--- a/include/asm-arm/smp.h
+++ b/include/asm-arm/smp.h
@@ -55,4 +55,18 @@ extern void smp_cross_call(cpumask_t callmap);
*/
extern int boot_secondary(unsigned int cpu, struct task_struct *);
+/*
+ * Perform platform specific initialisation of the specified CPU.
+ */
+extern void platform_secondary_init(unsigned int cpu);
+
+/*
+ * Initial data for bringing up a secondary CPU.
+ */
+struct secondary_data {
+ unsigned long pgdir;
+ void *stack;
+};
+extern struct secondary_data secondary_data;
+
#endif /* ifndef __ASM_ARM_SMP_H */