diff options
| -rw-r--r-- | arch/arm/kernel/head.S | 44 | ||||
| -rw-r--r-- | arch/arm/kernel/smp.c | 107 | ||||
| -rw-r--r-- | arch/arm/mach-integrator/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/mach-integrator/core.c | 20 | ||||
| -rw-r--r-- | arch/arm/mach-integrator/headsmp.S | 37 | ||||
| -rw-r--r-- | arch/arm/mach-integrator/leds.c | 4 | ||||
| -rw-r--r-- | arch/arm/mach-integrator/platsmp.c | 192 | ||||
| -rw-r--r-- | include/asm-arm/arch-integrator/smp.h | 19 | ||||
| -rw-r--r-- | include/asm-arm/smp.h | 14 |
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 */ |