[POWERPC] irqtrace support for 64-bit powerpc

This adds the low level irq tracing hooks to the powerpc architecture
needed to enable full lockdep functionality.

This is partly based on Johannes Berg's initial version.  I removed
the asm trampoline that isn't needed (thus improving performance) and
modified all sorts of bits and pieces, reworking most of the assembly,
etc...

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

5 files changed, 62 insertions, 30 deletions

diff --git a/include/asm-powerpc/exception.h b/include/asm-powerpc/exception.h
index 39abdb02fdef..329148b5acc6 100644
--- a/include/asm-powerpc/exception.h
+++ b/include/asm-powerpc/exception.h
@@ -228,18 +228,18 @@ label##_pSeries:							\
 BEGIN_FW_FTR_SECTION;                           \
         stb     r11,PACAHARDIRQEN(r13);         \
 END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES);   \
+        TRACE_DISABLE_INTS;                     \
 BEGIN_FW_FTR_SECTION;                           \
         mfmsr   r10;                            \
         ori     r10,r10,MSR_EE;                 \
         mtmsrd  r10,1;                          \
 END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
-
 #else
 #define DISABLE_INTS                            \
         li      r11,0;                          \
         stb     r11,PACASOFTIRQEN(r13);         \
-        stb     r11,PACAHARDIRQEN(r13)
-
+        stb     r11,PACAHARDIRQEN(r13);         \
+        TRACE_DISABLE_INTS
 #endif /* CONFIG_PPC_ISERIES */
 
 #define ENABLE_INTS                             \
diff --git a/include/asm-powerpc/hw_irq.h b/include/asm-powerpc/hw_irq.h
index a7b60bf639e0..ad8c9f7fd0e3 100644
--- a/include/asm-powerpc/hw_irq.h
+++ b/include/asm-powerpc/hw_irq.h
@@ -27,7 +27,7 @@ static inline unsigned long local_get_flags(void)
         return flags;
 }
 
-static inline unsigned long local_irq_disable(void)
+static inline unsigned long raw_local_irq_disable(void)
 {
         unsigned long flags, zero;
 
@@ -39,14 +39,15 @@ static inline unsigned long local_irq_disable(void)
         return flags;
 }
 
-extern void local_irq_restore(unsigned long);
+extern void raw_local_irq_restore(unsigned long);
 extern void iseries_handle_interrupts(void);
 
-#define local_irq_enable()      local_irq_restore(1)
-#define local_save_flags(flags) ((flags) = local_get_flags())
-#define local_irq_save(flags)   ((flags) = local_irq_disable())
+#define raw_local_irq_enable()          raw_local_irq_restore(1)
+#define raw_local_save_flags(flags)     ((flags) = local_get_flags())
+#define raw_local_irq_save(flags)       ((flags) = raw_local_irq_disable())
 
-#define irqs_disabled()         (local_get_flags() == 0)
+#define raw_irqs_disabled()             (local_get_flags() == 0)
+#define raw_irqs_disabled_flags(flags)  ((flags) == 0)
 
 #define __hard_irq_enable()     __mtmsrd(mfmsr() | MSR_EE, 1)
 #define __hard_irq_disable()    __mtmsrd(mfmsr() & ~MSR_EE, 1)
diff --git a/include/asm-powerpc/irqflags.h b/include/asm-powerpc/irqflags.h
index 7970cbaeaa54..cc6fdba33660 100644
--- a/include/asm-powerpc/irqflags.h
+++ b/include/asm-powerpc/irqflags.h
@@ -2,30 +2,43 @@
  * include/asm-powerpc/irqflags.h
  *
  * IRQ flags handling
- *
- * This file gets included from lowlevel asm headers too, to provide
- * wrapped versions of the local_irq_*() APIs, based on the
- * raw_local_irq_*() macros from the lowlevel headers.
  */
 #ifndef _ASM_IRQFLAGS_H
 #define _ASM_IRQFLAGS_H
 
+#ifndef __ASSEMBLY__
 /*
  * Get definitions for raw_local_save_flags(x), etc.
  */
 #include <asm-powerpc/hw_irq.h>
 
+#else
+#ifdef CONFIG_TRACE_IRQFLAGS
 /*
- * Do the CPU's IRQ-state tracing from assembly code. We call a
- * C function, so save all the C-clobbered registers:
+ * Most of the CPU's IRQ-state tracing is done from assembly code; we
+ * have to call a C function so call a wrapper that saves all the
+ * C-clobbered registers.
  */
-#ifdef CONFIG_TRACE_IRQFLAGS
-
-#error No support on PowerPC yet for CONFIG_TRACE_IRQFLAGS
-
+#define TRACE_ENABLE_INTS       bl .trace_hardirqs_on
+#define TRACE_DISABLE_INTS      bl .trace_hardirqs_off
+#define TRACE_AND_RESTORE_IRQ_PARTIAL(en,skip)  \
+        cmpdi   en, 0;                          \
+        bne     95f;                            \
+        stb     en,PACASOFTIRQEN(r13);          \
+        bl      .trace_hardirqs_off;            \
+        b       skip;                           \
+95:     bl      .trace_hardirqs_on;             \
+        li      en,1;
+#define TRACE_AND_RESTORE_IRQ(en)               \
+        TRACE_AND_RESTORE_IRQ_PARTIAL(en,96f);  \
+96:     stb     en,PACASOFTIRQEN(r13)
 #else
-# define TRACE_IRQS_ON
-# define TRACE_IRQS_OFF
+#define TRACE_ENABLE_INTS
+#define TRACE_DISABLE_INTS
+#define TRACE_AND_RESTORE_IRQ_PARTIAL(en,skip)
+#define TRACE_AND_RESTORE_IRQ(en)               \
+        stb     en,PACASOFTIRQEN(r13)
+#endif
 #endif
 
 #endif
diff --git a/include/asm-powerpc/rwsem.h b/include/asm-powerpc/rwsem.h
index cefc14728cc5..a6cc93b78b98 100644
--- a/include/asm-powerpc/rwsem.h
+++ b/include/asm-powerpc/rwsem.h
@@ -32,11 +32,20 @@ struct rw_semaphore {
 #define RWSEM_ACTIVE_WRITE_BIAS         (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
         spinlock_t              wait_lock;
         struct list_head        wait_list;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+        struct lockdep_map      dep_map;
+#endif
 };
 
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define __RWSEM_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname }
+#else
+# define __RWSEM_DEP_MAP_INIT(lockname)
+#endif
+
 #define __RWSEM_INITIALIZER(name) \
-        { RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, \
-          LIST_HEAD_INIT((name).wait_list) }
+        { RWSEM_UNLOCKED_VALUE, __SPIN_LOCK_UNLOCKED((name).wait_lock), \
+          LIST_HEAD_INIT((name).wait_list) __RWSEM_DEP_MAP_INIT(name) }
 
 #define DECLARE_RWSEM(name)             \
         struct rw_semaphore name = __RWSEM_INITIALIZER(name)
@@ -46,12 +55,15 @@ extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
 extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem);
 extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
 
-static inline void init_rwsem(struct rw_semaphore *sem)
-{
-        sem->count = RWSEM_UNLOCKED_VALUE;
-        spin_lock_init(&sem->wait_lock);
-        INIT_LIST_HEAD(&sem->wait_list);
-}
+extern void __init_rwsem(struct rw_semaphore *sem, const char *name,
+                         struct lock_class_key *key);
+
+#define init_rwsem(sem)                                 \
+        do {                                            \
+                static struct lock_class_key __key;     \
+                                                        \
+                __init_rwsem((sem), #sem, &__key);      \
+        } while (0)
 
 /*
  * lock for reading
@@ -78,7 +90,7 @@ static inline int __down_read_trylock(struct rw_semaphore *sem)
 /*
  * lock for writing
  */
-static inline void __down_write(struct rw_semaphore *sem)
+static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
 {
         int tmp;
 
@@ -88,6 +100,11 @@ static inline void __down_write(struct rw_semaphore *sem)
                 rwsem_down_write_failed(sem);
 }
 
+static inline void __down_write(struct rw_semaphore *sem)
+{
+        __down_write_nested(sem, 0);
+}
+
 static inline int __down_write_trylock(struct rw_semaphore *sem)
 {
         int tmp;
diff --git a/include/asm-powerpc/spinlock.h b/include/asm-powerpc/spinlock.h
index cc4cfceac67c..258c93993190 100644
--- a/include/asm-powerpc/spinlock.h
+++ b/include/asm-powerpc/spinlock.h
@@ -19,6 +19,7 @@
  *
  * (the type definitions are in asm/spinlock_types.h)
  */
+#include <linux/irqflags.h>
 #ifdef CONFIG_PPC64
 #include <asm/paca.h>
 #include <asm/hvcall.h>