Fix __save_flags() to not complain when smp_processor_id() is used

in a preemptible region (it is always safe).

Signed-off-by: Keir Fraser <keir@xensource.com>

diff --git a/linux-2.6-xen-sparse/include/asm-xen/asm-i386/system.h b/linux-2.6-xen-sparse/include/asm-xen/asm-i386/system.h
index a627fbf4fc72a892eddff44f55c86aef4edfebb9..f930c4cec6bd45e123bb6adc14eab0cd45253c98 100644 (file)
--- a/linux-2.6-xen-sparse/include/asm-xen/asm-i386/system.h
+++ b/linux-2.6-xen-sparse/include/asm-xen/asm-i386/system.h
@@ -497,11 +497,22 @@ __asm__ __volatile__("6667:movl %1, %0\n6668:\n"                    \
  * includes these barriers, for example.
  */
 
+/*
+ * Don't use smp_processor_id() in preemptible code: debug builds will barf.
+ * It's okay in these cases as we only read the upcall mask in preemptible
+ * regions, which is always safe.
+ */
+#ifdef CONFIG_SMP
+#define __this_cpu()   __smp_processor_id()
+#else
+#define __this_cpu()   0
+#endif
+
 #define __cli()                                                                \
 do {                                                                   \
        vcpu_info_t *_vcpu;                                             \
        preempt_disable();                                              \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
        _vcpu->evtchn_upcall_mask = 1;                                  \
        preempt_enable_no_resched();                                    \
        barrier();                                                      \
@@ -512,7 +523,7 @@ do {                                                                        \
        vcpu_info_t *_vcpu;                                             \
        barrier();                                                      \
        preempt_disable();                                              \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
        _vcpu->evtchn_upcall_mask = 0;                                  \
        barrier(); /* unmask then check (avoid races) */                \
        if ( unlikely(_vcpu->evtchn_upcall_pending) )                   \
@@ -523,7 +534,7 @@ do {                                                                        \
 #define __save_flags(x)                                                        \
 do {                                                                   \
        vcpu_info_t *_vcpu;                                             \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
        (x) = _vcpu->evtchn_upcall_mask;                                \
 } while (0)
 
@@ -532,7 +543,7 @@ do {                                                                        \
        vcpu_info_t *_vcpu;                                             \
        barrier();                                                      \
        preempt_disable();                                              \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
        if ((_vcpu->evtchn_upcall_mask = (x)) == 0) {                   \
                barrier(); /* unmask then check (avoid races) */        \
                if ( unlikely(_vcpu->evtchn_upcall_pending) )           \
@@ -548,7 +559,7 @@ do {                                                                        \
 do {                                                                   \
        vcpu_info_t *_vcpu;                                             \
        preempt_disable();                                              \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
        (x) = _vcpu->evtchn_upcall_mask;                                \
        _vcpu->evtchn_upcall_mask = 1;                                  \
        preempt_enable_no_resched();                                    \
@@ -561,14 +572,8 @@ do {                                                                       \
 #define local_irq_disable()    __cli()
 #define local_irq_enable()     __sti()
 
-/* Don't use smp_processor_id: this is called in debug versions of that fn. */
-#ifdef CONFIG_SMP
-#define irqs_disabled()                        \
-    HYPERVISOR_shared_info->vcpu_data[__smp_processor_id()].evtchn_upcall_mask
-#else
-#define irqs_disabled()                        \
-    HYPERVISOR_shared_info->vcpu_data[0].evtchn_upcall_mask
-#endif
+#define irqs_disabled()                                                        \
+       HYPERVISOR_shared_info->vcpu_data[__this_cpu()].evtchn_upcall_mask
 
 /*
  * disable hlt during certain critical i/o operations

diff --git a/linux-2.6-xen-sparse/include/asm-xen/asm-x86_64/system.h b/linux-2.6-xen-sparse/include/asm-xen/asm-x86_64/system.h
index d06d1485ebe29802194bfb3724064bb2e3dc927f..cf3badc58c28c2b63408d46975932a19a0f5eba8 100644 (file)
--- a/linux-2.6-xen-sparse/include/asm-xen/asm-x86_64/system.h
+++ b/linux-2.6-xen-sparse/include/asm-xen/asm-x86_64/system.h
@@ -321,11 +321,22 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
  * includes these barriers, for example.
  */
 
+/*
+ * Don't use smp_processor_id() in preemptible code: debug builds will barf.
+ * It's okay in these cases as we only read the upcall mask in preemptible
+ * regions, which is always safe.
+ */
+#ifdef CONFIG_SMP
+#define __this_cpu()   __smp_processor_id()
+#else
+#define __this_cpu()   0
+#endif
+
 #define __cli()                                                                \
 do {                                                                   \
        vcpu_info_t *_vcpu;                                             \
        preempt_disable();                                              \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
        _vcpu->evtchn_upcall_mask = 1;                                  \
        preempt_enable_no_resched();                                    \
        barrier();                                                      \
@@ -336,7 +347,7 @@ do {                                                                        \
        vcpu_info_t *_vcpu;                                             \
        barrier();                                                      \
        preempt_disable();                                              \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
        _vcpu->evtchn_upcall_mask = 0;                                  \
        barrier(); /* unmask then check (avoid races) */                \
        if ( unlikely(_vcpu->evtchn_upcall_pending) )                   \
@@ -347,7 +358,7 @@ do {                                                                        \
 #define __save_flags(x)                                                        \
 do {                                                                   \
        vcpu_info_t *_vcpu;                                             \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
        (x) = _vcpu->evtchn_upcall_mask;                                \
 } while (0)
 
@@ -356,7 +367,7 @@ do {                                                                        \
        vcpu_info_t *_vcpu;                                             \
        barrier();                                                      \
        preempt_disable();                                              \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
        if ((_vcpu->evtchn_upcall_mask = (x)) == 0) {                   \
                barrier(); /* unmask then check (avoid races) */        \
                if ( unlikely(_vcpu->evtchn_upcall_pending) )           \
@@ -372,7 +383,7 @@ do {                                                                        \
 do {                                                                   \
        vcpu_info_t *_vcpu;                                             \
        preempt_disable();                                              \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
        (x) = _vcpu->evtchn_upcall_mask;                                \
        _vcpu->evtchn_upcall_mask = 1;                                  \
        preempt_enable_no_resched();                                    \
@@ -387,14 +398,8 @@ void cpu_idle_wait(void);
 #define local_irq_disable()    __cli()
 #define local_irq_enable()     __sti()
 
-/* Don't use smp_processor_id: this is called in debug versions of that fn. */
-#ifdef CONFIG_SMP
-#define irqs_disabled()                        \
-    HYPERVISOR_shared_info->vcpu_data[__smp_processor_id()].evtchn_upcall_mask
-#else
-#define irqs_disabled()                        \
-    HYPERVISOR_shared_info->vcpu_data[0].evtchn_upcall_mask
-#endif
+#define irqs_disabled()                                                        \
+       HYPERVISOR_shared_info->vcpu_data[__this_cpu()].evtchn_upcall_mask
 
 /*
  * disable hlt during certain critical i/o operations