Mailing List Archive

# HG changeset patch
# User Tim Deegan <tim@xen.org>
# Date 1330018799 0
# Node ID d35b52e5fde829dfbaf3da73e0716d004faded2f
# Parent fd78d23ba19de4129e21cdc7303848b105057227
arm: Boot secondary CPUs into C

Signed-off-by: Tim Deegan <tim@xen.org>

diff -r fd78d23ba19d -r d35b52e5fde8 xen/arch/arm/gic.c
--- a/xen/arch/arm/gic.c Thu Feb 23 17:39:59 2012 +0000
+++ b/xen/arch/arm/gic.c Thu Feb 23 17:39:59 2012 +0000
@@ -241,7 +241,6 @@ static void __cpuinit gic_hyp_init(void)

vtr = GICH[GICH_VTR];
nr_lrs = (vtr & GICH_VTR_NRLRGS) + 1;
- printk("GICH: %d list registers available\n", nr_lrs);

GICH[GICH_HCR] = GICH_HCR_EN;
GICH[GICH_MISR] = GICH_MISR_EOI;
@@ -274,6 +273,15 @@ int __init gic_init(void)
return gic.cpus;
}

+/* Set up the per-CPU parts of the GIC for a secondary CPU */
+void __cpuinit gic_init_secondary_cpu(void)
+{
+ spin_lock(&gic.lock);
+ gic_cpu_init();
+ gic_hyp_init();
+ spin_unlock(&gic.lock);
+}
+
void gic_route_irqs(void)
{
/* XXX should get these from DT */
diff -r fd78d23ba19d -r d35b52e5fde8 xen/arch/arm/gic.h
--- a/xen/arch/arm/gic.h Thu Feb 23 17:39:59 2012 +0000
+++ b/xen/arch/arm/gic.h Thu Feb 23 17:39:59 2012 +0000
@@ -140,6 +140,8 @@ extern int gic_route_irq_to_guest(struct
extern void gic_interrupt(struct cpu_user_regs *regs, int is_fiq);
/* Bring up the interrupt controller, and report # cpus attached */
extern int gic_init(void);
+/* Bring up a secondary CPU's per-CPU GIC interface */
+extern void gic_init_secondary_cpu(void);
/* setup the gic virtual interface for a guest */
extern void gicv_setup(struct domain *d);
#endif
diff -r fd78d23ba19d -r d35b52e5fde8 xen/arch/arm/head.S
--- a/xen/arch/arm/head.S Thu Feb 23 17:39:59 2012 +0000
+++ b/xen/arch/arm/head.S Thu Feb 23 17:39:59 2012 +0000
@@ -305,17 +305,23 @@ paging:
* and brought up the memory allocator, non-boot CPUs can get their
* own stacks and enter C. */
1: wfe
- b 1b
+ dsb
+ ldr r0, =smp_up_cpu
+ ldr r1, [r0] /* Which CPU is being booted? */
+ teq r1, r12 /* Is it us? */
+ bne 1b

launch:
- ldr sp, =init_stack /* Supply a stack */
+ ldr r0, =init_stacks /* Find the boot-time stack */
+ ldr sp, [r0, r12, lsl #2] /* (the one for this CPU) */
add sp, #STACK_SIZE /* (which grows down from the top). */
sub sp, #CPUINFO_sizeof /* Make room for CPU save record */
mov r0, r10 /* Marshal args: - phys_offset */
mov r1, r7 /* - machine type */
mov r2, r8 /* - ATAG address */
- mov r3, r12 /* - CPU ID */
- b start_xen /* and disappear into the land of C */
+ movs r3, r12 /* - CPU ID */
+ beq start_xen /* and disappear into the land of C */
+ b start_secondary /* (to the appropriate entry point) */

/* Fail-stop
* r0: string explaining why */
diff -r fd78d23ba19d -r d35b52e5fde8 xen/arch/arm/setup.c
--- a/xen/arch/arm/setup.c Thu Feb 23 17:39:59 2012 +0000
+++ b/xen/arch/arm/setup.c Thu Feb 23 17:39:59 2012 +0000
@@ -38,9 +38,6 @@
#include <asm/setup.h>
#include "gic.h"

-/* Xen stack for bringing up the first CPU. */
-unsigned char __initdata init_stack[STACK_SIZE] __attribute__((__aligned__(STACK_SIZE)));
-
extern const char __init_begin[], __init_end[], __bss_start[];

/* Spinlock for serializing CPU bringup */
@@ -179,6 +176,8 @@ void __init start_xen(unsigned long boot
console_init_preirq();
#endif

+ percpu_init_areas();
+
cpus = gic_init();

printk("Waiting for %i other CPUs to be ready\n", cpus - 1);
diff -r fd78d23ba19d -r d35b52e5fde8 xen/arch/arm/smpboot.c
--- a/xen/arch/arm/smpboot.c Thu Feb 23 17:39:59 2012 +0000
+++ b/xen/arch/arm/smpboot.c Thu Feb 23 17:39:59 2012 +0000
@@ -16,10 +16,15 @@
* GNU General Public License for more details.
*/

+#include <xen/cpu.h>
#include <xen/cpumask.h>
+#include <xen/errno.h>
+#include <xen/init.h>
+#include <xen/mm.h>
+#include <xen/sched.h>
#include <xen/smp.h>
-#include <xen/init.h>
-#include <xen/errno.h>
+#include <xen/softirq.h>
+#include "gic.h"

cpumask_t cpu_online_map;
EXPORT_SYMBOL(cpu_online_map);
@@ -28,6 +33,14 @@ EXPORT_SYMBOL(cpu_online_map);
cpumask_t cpu_possible_map;
EXPORT_SYMBOL(cpu_possible_map);

+/* Xen stack for bringing up the first CPU. */
+static unsigned char cpu0_stack[STACK_SIZE]
+ __attribute__((__aligned__(STACK_SIZE)));
+
+/* Remember where the boot-time stacks live */
+/* TODO: overhaul this, and get_processor_id(), for per-vcpu stacks */
+unsigned char *init_stacks[NR_CPUS] = { cpu0_stack, 0 };
+
void __init
smp_prepare_cpus (unsigned int max_cpus)
{
@@ -43,11 +56,43 @@ smp_prepare_cpus (unsigned int max_cpus)
cpumask_copy(&cpu_present_map, &cpu_possible_map);
}

-/* Bring up a non-boot CPU */
-int __cpu_up(unsigned int cpu)
+/* Shared state for coordinating CPU bringup */
+unsigned long smp_up_cpu = 0;
+
+/* Boot the current CPU */
+void __cpuinit start_secondary(unsigned long boot_phys_offset,
+ unsigned long arm_type,
+ unsigned long atag_paddr,
+ unsigned long cpuid)
{
- /* Not yet... */
- return -ENODEV;
+ memset(get_cpu_info(), 0, sizeof (struct cpu_info));
+
+ /* TODO: handle boards where CPUIDs are not contiguous */
+ set_processor_id(cpuid);
+
+ /* Setup Hyp vector base */
+ WRITE_CP32((uint32_t) hyp_traps_vector, HVBAR);
+
+ dprintk(XENLOG_DEBUG, "CPU %li awake.\n", cpuid);
+
+ gic_init_secondary_cpu();
+
+ set_current(idle_vcpu[cpuid]);
+ this_cpu(curr_vcpu) = current;
+
+ /* Run local notifiers */
+ notify_cpu_starting(cpuid);
+ wmb();
+
+ /* Now report this CPU is up */
+ cpumask_set_cpu(cpuid, &cpu_online_map);
+ wmb();
+
+ local_irq_enable();
+
+ dprintk(XENLOG_DEBUG, "CPU %li booted.\n", cpuid);
+
+ startup_cpu_idle_loop();
}

/* Shut down the current CPU */
@@ -57,6 +102,32 @@ void __cpu_disable(void)
BUG();
}

+/* Bring up a remote CPU */
+int __cpu_up(unsigned int cpu)
+{
+ unsigned char *stack;
+
+ /* Remote CPU needs a stack to boot on. */
+ stack = alloc_xenheap_pages(STACK_ORDER, 0);
+ if ( !stack )
+ return -ENOMEM;
+ ASSERT(init_stacks[cpu] == NULL);
+ init_stacks[cpu] = stack;
+
+ /* Unblock the CPU. It should be waiting in the loop in head.S
+ * for an event to arrive when smp_up_cpu matches its cpuid. */
+ smp_up_cpu = cpu;
+ asm volatile("dsb; isb; sev");
+
+ while ( !cpu_online(cpu) )
+ {
+ cpu_relax();
+ process_pending_softirqs();
+ }
+
+ return 0;
+}
+
/* Wait for a remote CPU to die */
void __cpu_die(unsigned int cpu)
{

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