# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1202927412 0
# Node ID e1dde6f8bc873b74786feb603289c502c9a43ed9
# Parent e7085b40dc08d3bff167bcad05b509da22c64e04
xen: Clean up SMP/hotplug headers and implementation a bit.
Signed-off-by: Keir Fraser <keir.fraser@xxxxxxxxxx>
---
xen/arch/x86/smpboot.c | 5 +-
xen/common/stop_machine.c | 20 ++---------
xen/include/xen/smp.h | 72 +++--------------------------------------
xen/include/xen/stop_machine.h | 11 ------
4 files changed, 14 insertions(+), 94 deletions(-)
diff -r e7085b40dc08 -r e1dde6f8bc87 xen/arch/x86/smpboot.c
--- a/xen/arch/x86/smpboot.c Wed Feb 13 18:09:27 2008 +0000
+++ b/xen/arch/x86/smpboot.c Wed Feb 13 18:30:12 2008 +0000
@@ -112,7 +112,7 @@ DEFINE_PER_CPU(int, cpu_state) = { 0 };
DEFINE_PER_CPU(int, cpu_state) = { 0 };
static void *stack_base[NR_CPUS] __cacheline_aligned;
-spinlock_t cpu_add_remove_lock;
+static DEFINE_SPINLOCK(cpu_add_remove_lock);
/*
* The bootstrap kernel entry code has set these up. Save them for
@@ -1164,7 +1164,6 @@ void __devinit smp_prepare_boot_cpu(void
cpu_set(smp_processor_id(), cpu_present_map);
cpu_set(smp_processor_id(), cpu_possible_map);
per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
- spin_lock_init(&cpu_add_remove_lock);
}
#ifdef CONFIG_HOTPLUG_CPU
@@ -1298,7 +1297,7 @@ int cpu_down(unsigned int cpu)
printk("Prepare to bring CPU%d down...\n", cpu);
- err = __stop_machine_run(take_cpu_down, NULL, cpu);
+ err = stop_machine_run(take_cpu_down, NULL, cpu);
if ( err < 0 )
goto out;
diff -r e7085b40dc08 -r e1dde6f8bc87 xen/common/stop_machine.c
--- a/xen/common/stop_machine.c Wed Feb 13 18:09:27 2008 +0000
+++ b/xen/common/stop_machine.c Wed Feb 13 18:30:12 2008 +0000
@@ -22,12 +22,13 @@
#include <xen/config.h>
#include <xen/init.h>
+#include <xen/sched.h>
#include <xen/spinlock.h>
-#include <asm/smp.h>
+#include <xen/softirq.h>
+#include <xen/errno.h>
+#include <xen/smp.h>
#include <asm/current.h>
-#include <xen/softirq.h>
#include <asm/processor.h>
-#include <xen/errno.h>
enum stopmachine_state {
STOPMACHINE_START,
@@ -61,7 +62,7 @@ static void stopmachine_set_state(enum s
cpu_relax();
}
-int __stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu)
+int stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu)
{
cpumask_t allbutself;
unsigned int i, nr_cpus;
@@ -116,17 +117,6 @@ int __stop_machine_run(int (*fn)(void *)
return ret;
}
-int stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu)
-{
- int ret;
-
- lock_cpu_hotplug();
- ret = __stop_machine_run(fn, data, cpu);
- unlock_cpu_hotplug();
-
- return ret;
-}
-
static void stopmachine_softirq(void)
{
enum stopmachine_state state = STOPMACHINE_START;
diff -r e7085b40dc08 -r e1dde6f8bc87 xen/include/xen/smp.h
--- a/xen/include/xen/smp.h Wed Feb 13 18:09:27 2008 +0000
+++ b/xen/include/xen/smp.h Wed Feb 13 18:30:12 2008 +0000
@@ -1,21 +1,8 @@
-#ifndef __LINUX_SMP_H
-#define __LINUX_SMP_H
-
-/*
- * Generic SMP support
- * Alan Cox. <alan@xxxxxxxxxx>
- */
+#ifndef __XEN_SMP_H__
+#define __XEN_SMP_H__
#include <xen/config.h>
-
-#ifdef CONFIG_SMP
-
#include <asm/smp.h>
-
-/*
- * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
- * (defined in asm header):
- */
/*
* stops all CPUs but the current one:
@@ -66,38 +53,6 @@ extern int on_selected_cpus(
*/
void smp_prepare_boot_cpu(void);
-#else
-
-/*
- * These macros fold the SMP functionality into a single CPU system
- */
-
-#define smp_send_event_check_mask(m) ((void)0)
-#define smp_send_event_check_cpu(p) ((void)0)
-#define raw_smp_processor_id() 0
-#define hard_smp_processor_id() 0
-#define smp_call_function(func,info,retry,wait) ({ do {} while (0); 0;
})
-#define num_booting_cpus() 1
-#define smp_prepare_boot_cpu() do {} while (0)
-
-static inline int on_selected_cpus(
- cpumask_t selected,
- void (*func) (void *info),
- void *info,
- int retry,
- int wait)
-{
- if ( cpu_isset(0, selected) )
- {
- local_irq_disable();
- func(info);
- local_irq_enable();
- }
- return 0;
-}
-
-#endif
-
/*
* Call a function on all processors
*/
@@ -112,21 +67,8 @@ static inline int on_each_cpu(
#define smp_processor_id() raw_smp_processor_id()
-#ifdef CONFIG_HOTPLUG_CPU
-extern spinlock_t cpu_add_remove_lock;
-/*
- * FIXME: need a better lock mechanism when real cpu hotplug is later
- * supported, since spinlock may cause dead lock:
- * cpu0: in stop_machine with lock held. Wait for cpu1 to respond
- * to stop request
- * cpu1: spin loop on lock upon cpu hotplug request from guest,
- * without chance to handle softirq
- * ...
- */
-#define lock_cpu_hotplug() spin_lock(&cpu_add_remove_lock);
-#define unlock_cpu_hotplug() spin_unlock(&cpu_add_remove_lock);
-#else
-#define lock_cpu_hotplug() do { } while ( 0 )
-#define unlock_cpu_hotplug() do { } while ( 0 )
-#endif
-#endif
+/* No Xen contexts can be preempted by CPU hotplug. */
+#define lock_cpu_hotplug() ((void)0)
+#define unlock_cpu_hotplug() ((void)0)
+
+#endif /* __XEN_SMP_H__ */
diff -r e7085b40dc08 -r e1dde6f8bc87 xen/include/xen/stop_machine.h
--- a/xen/include/xen/stop_machine.h Wed Feb 13 18:09:27 2008 +0000
+++ b/xen/include/xen/stop_machine.h Wed Feb 13 18:30:12 2008 +0000
@@ -16,15 +16,4 @@
* grabbing every spinlock in the kernel. */
int stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu);
-/**
- * __stop_machine_run: freeze the machine on all CPUs and run this function
- * @fn: the function to run
- * @data: the data ptr for the @fn
- * @cpu: the cpu to run @fn on (or any, if @cpu == NR_CPUS.
- *
- * Description: This is a special version of the above, without explicit
- * lock acquisition. Used by hotplug cpu.
- */
-int __stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu);
-
#endif /* __XEN_STOP_MACHINE_H__ */
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