Merge with ../linux-2.6-smp

7 files changed, 403 insertions, 2 deletions

diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 4733877296d4..bd4823c74645 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 ecc8c3332408..45ed036336e0 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 158daaf9e3b0..ebb255bdce8a 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 bd17b5154311..d302f0405fd2 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 000000000000..ceaa88e30d70
--- /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 d2c0ab21150c..f1436e683b49 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 000000000000..ead15dfcb53d
--- /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();
+}