4 files changed, 60 insertions, 5 deletions

diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index 8d6f87169577..1988807d415e 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -81,7 +81,8 @@ struct thread_struct {
         mm_segment_t mm_segment;
         unsigned long prot_addr;        /* address of protection-excep.     */
         unsigned int trap_no;
-        per_struct per_info;
+        struct per_regs per_user;       /* User specified PER registers */
+        struct per_event per_event;     /* Cause of the last PER trap */
         /* pfault_wait is used to block the process on a pfault event */
         unsigned long pfault_wait;
 };
diff --git a/arch/s390/include/asm/ptrace.h b/arch/s390/include/asm/ptrace.h
index d9d42b1e46fa..9ad628a8574a 100644
--- a/arch/s390/include/asm/ptrace.h
+++ b/arch/s390/include/asm/ptrace.h
@@ -331,10 +331,60 @@ struct pt_regs
         unsigned short ilc;
         unsigned short svcnr;
 };
+
+/*
+ * Program event recording (PER) register set.
+ */
+struct per_regs {
+        unsigned long control;          /* PER control bits */
+        unsigned long start;            /* PER starting address */
+        unsigned long end;              /* PER ending address */
+};
+
+/*
+ * PER event contains information about the cause of the last PER exception.
+ */
+struct per_event {
+        unsigned short cause;           /* PER code, ATMID and AI */
+        unsigned long address;          /* PER address */
+        unsigned char paid;             /* PER access identification */
+};
+
+/*
+ * Simplified per_info structure used to decode the ptrace user space ABI.
+ */
+struct per_struct_kernel {
+        unsigned long cr9;              /* PER control bits */
+        unsigned long cr10;             /* PER starting address */
+        unsigned long cr11;             /* PER ending address */
+        unsigned long bits;             /* Obsolete software bits */
+        unsigned long starting_addr;    /* User specified start address */
+        unsigned long ending_addr;      /* User specified end address */
+        unsigned short perc_atmid;      /* PER trap ATMID */
+        unsigned long address;          /* PER trap instruction address */
+        unsigned char access_id;        /* PER trap access identification */
+};
+
+#define PER_EVENT_MASK                  0xE9000000UL
+
+#define PER_EVENT_BRANCH                0x80000000UL
+#define PER_EVENT_IFETCH                0x40000000UL
+#define PER_EVENT_STORE                 0x20000000UL
+#define PER_EVENT_STORE_REAL            0x08000000UL
+#define PER_EVENT_NULLIFICATION         0x01000000UL
+
+#define PER_CONTROL_MASK                0x00a00000UL
+
+#define PER_CONTROL_BRANCH_ADDRESS      0x00800000UL
+#define PER_CONTROL_ALTERATION          0x00200000UL
+
 #endif
 
 /*
- * Now for the program event recording (trace) definitions.
+ * Now for the user space program event recording (trace) definitions.
+ * The following structures are used only for the ptrace interface, don't
+ * touch or even look at it if you don't want to modify the user-space
+ * ptrace interface. In particular stay away from it for in-kernel PER.
  */
 typedef struct
 {
diff --git a/arch/s390/include/asm/system.h b/arch/s390/include/asm/system.h
index 4ab2779fdb02..6710b0eac165 100644
--- a/arch/s390/include/asm/system.h
+++ b/arch/s390/include/asm/system.h
@@ -20,6 +20,7 @@
 struct task_struct;
 
 extern struct task_struct *__switch_to(void *, void *);
+extern void update_per_regs(struct task_struct *task);
 
 static inline void save_fp_regs(s390_fp_regs *fpregs)
 {
@@ -93,6 +94,7 @@ static inline void restore_access_regs(unsigned int *acrs)
         if (next->mm) {                                                 \
                 restore_fp_regs(&next->thread.fp_regs);                 \
                 restore_access_regs(&next->thread.acrs[0]);             \
+                update_per_regs(next);                                  \
         }                                                               \
         prev = __switch_to(prev,next);                                  \
 } while (0)
diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h
index 814520217945..ebc77091466f 100644
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -88,7 +88,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_SIGPENDING          2       /* signal pending */
 #define TIF_NEED_RESCHED        3       /* rescheduling necessary */
 #define TIF_RESTART_SVC         4       /* restart svc with new svc number */
-#define TIF_SINGLE_STEP         6       /* deliver sigtrap on return to user */
+#define TIF_PER_TRAP            6       /* deliver sigtrap on return to user */
 #define TIF_MCCK_PENDING        7       /* machine check handling is pending */
 #define TIF_SYSCALL_TRACE       8       /* syscall trace active */
 #define TIF_SYSCALL_AUDIT       9       /* syscall auditing active */
@@ -99,14 +99,15 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_31BIT               17      /* 32bit process */
 #define TIF_MEMDIE              18      /* is terminating due to OOM killer */
 #define TIF_RESTORE_SIGMASK     19      /* restore signal mask in do_signal() */
-#define TIF_FREEZE              20      /* thread is freezing for suspend */
+#define TIF_SINGLE_STEP         20      /* This task is single stepped */
+#define TIF_FREEZE              21      /* thread is freezing for suspend */
 
 #define _TIF_NOTIFY_RESUME      (1<<TIF_NOTIFY_RESUME)
 #define _TIF_RESTORE_SIGMASK    (1<<TIF_RESTORE_SIGMASK)
 #define _TIF_SIGPENDING         (1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED       (1<<TIF_NEED_RESCHED)
 #define _TIF_RESTART_SVC        (1<<TIF_RESTART_SVC)
-#define _TIF_SINGLE_STEP        (1<<TIF_SINGLE_STEP)
+#define _TIF_PER_TRAP           (1<<TIF_PER_TRAP)
 #define _TIF_MCCK_PENDING       (1<<TIF_MCCK_PENDING)
 #define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
 #define _TIF_SYSCALL_AUDIT      (1<<TIF_SYSCALL_AUDIT)
@@ -114,6 +115,7 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
 #define _TIF_POLLING_NRFLAG     (1<<TIF_POLLING_NRFLAG)
 #define _TIF_31BIT              (1<<TIF_31BIT)
+#define _TIF_SINGLE_STEP        (1<<TIF_FREEZE)
 #define _TIF_FREEZE             (1<<TIF_FREEZE)
 
 #endif /* __KERNEL__ */