3 files changed, 33 insertions, 38 deletions

diff --git a/arch/arc/include/asm/arcregs.h b/arch/arc/include/asm/arcregs.h
index 122e9af46824..355cb470c2a4 100644
--- a/arch/arc/include/asm/arcregs.h
+++ b/arch/arc/include/asm/arcregs.h
@@ -60,6 +60,7 @@
 #define ECR_V_ITLB_MISS                 0x21
 #define ECR_V_DTLB_MISS                 0x22
 #define ECR_V_PROTV                     0x23
+#define ECR_V_TRAP                      0x25
 
 /* Protection Violation Exception Cause Code Values */
 #define ECR_C_PROTV_INST_FETCH          0x00
@@ -77,6 +78,9 @@
 #define ECR_C_BIT_DTLB_LD_MISS          8
 #define ECR_C_BIT_DTLB_ST_MISS          9
 
+/* Dummy ECR values for Interrupts */
+#define event_IRQ1              0x0031abcd
+#define event_IRQ2              0x0032abcd
 
 /* Auxiliary registers */
 #define AUX_IDENTITY            4
diff --git a/arch/arc/include/asm/entry.h b/arch/arc/include/asm/entry.h
index de01bc842a9a..8943c028d4bb 100644
--- a/arch/arc/include/asm/entry.h
+++ b/arch/arc/include/asm/entry.h
@@ -309,7 +309,7 @@
 #endif
 
         /* Save Pre Intr/Exception User SP on kernel stack */
-        st.a    sp, [r9, -16]   ; Make room for orig_r0, orig_r8, user_r25
+        st.a    sp, [r9, -16]   ; Make room for orig_r0, ECR, user_r25
 
         /* CAUTION:
          * SP should be set at the very end when we are done with everything
@@ -391,9 +391,10 @@
  * Note that syscalls are implemented via TRAP which is also a exception
  * from CPU's point of view
  *-------------------------------------------------------------*/
-.macro SAVE_ALL_EXCEPTION   marker
+.macro SAVE_ALL_SYS
 
-        st      \marker, [sp, 8]        /* orig_r8 */
+        lr      r9, [ecr]
+        st      r9, [sp, 8]    /* ECR */
         st      r0, [sp, 4]    /* orig_r0, needed only for sys calls */
 
         /* Restore r9 used to code the early prologue */
@@ -412,20 +413,6 @@
 .endm
 
 /*--------------------------------------------------------------
- * Save scratch regs for exceptions
- *-------------------------------------------------------------*/
-.macro SAVE_ALL_SYS
-        SAVE_ALL_EXCEPTION  orig_r8_IS_EXCPN
-.endm
-
-/*--------------------------------------------------------------
- * Save scratch regs for sys calls
- *-------------------------------------------------------------*/
-.macro SAVE_ALL_TRAP
-        SAVE_ALL_EXCEPTION  orig_r8_IS_SCALL
-.endm
-
-/*--------------------------------------------------------------
  * Restore all registers used by system call or Exceptions
  * SP should always be pointing to the next free stack element
  * when entering this macro.
@@ -452,7 +439,7 @@
         RESTORE_R12_TO_R0
 
         ld  sp, [sp] /* restore original sp */
-        /* orig_r0, orig_r8, user_r25 skipped automatically */
+        /* orig_r0, ECR, user_r25 skipped automatically */
 .endm
 
 
@@ -469,7 +456,7 @@
 #endif
 
         /* now we are ready to save the remaining context :) */
-        st      orig_r8_IS_IRQ1, [sp, 8]    /* Event Type */
+        st      event_IRQ1, [sp, 8]    /* Dummy ECR */
         st      0, [sp, 4]    /* orig_r0 , N/A for IRQ */
 
         SAVE_R0_TO_R12
@@ -494,7 +481,7 @@
         ld  r9, [@int2_saved_reg]
 
         /* now we are ready to save the remaining context :) */
-        st      orig_r8_IS_IRQ2, [sp, 8]    /* Event Type */
+        st      event_IRQ2, [sp, 8]    /* Dummy ECR */
         st      0, [sp, 4]    /* orig_r0 , N/A for IRQ */
 
         SAVE_R0_TO_R12
@@ -535,7 +522,7 @@
         RESTORE_R12_TO_R0
 
         ld  sp, [sp] /* restore original sp */
-        /* orig_r0, orig_r8, user_r25 skipped automatically */
+        /* orig_r0, ECR, user_r25 skipped automatically */
 .endm
 
 .macro RESTORE_ALL_INT2
@@ -554,7 +541,7 @@
         RESTORE_R12_TO_R0
 
         ld  sp, [sp] /* restore original sp */
-        /* orig_r0, orig_r8, user_r25 skipped automatically */
+        /* orig_r0, ECR, user_r25 skipped automatically */
 .endm
 
 
diff --git a/arch/arc/include/asm/ptrace.h b/arch/arc/include/asm/ptrace.h
index 7b2de6f7025a..c9938e7a7dbd 100644
--- a/arch/arc/include/asm/ptrace.h
+++ b/arch/arc/include/asm/ptrace.h
@@ -44,15 +44,24 @@ struct pt_regs {
         long sp;        /* user/kernel sp depending on where we came from  */
         long orig_r0;
 
-        /*to distinguish bet excp, syscall, irq */
+        /*
+         * To distinguish bet excp, syscall, irq
+         * For traps and exceptions, Exception Cause Register.
+         *      ECR: <00> <VV> <CC> <PP>
+         *      Last word used by Linux for extra state mgmt (syscall-restart)
+         * For interrupts, use artificial ECR values to note current prio-level
+         */
         union {
+                struct {
 #ifdef CONFIG_CPU_BIG_ENDIAN
-                /* so that assembly code is same for LE/BE */
-                unsigned long orig_r8:16, event:16;
+                        unsigned long state:8, ecr_vec:8,
+                                      ecr_cause:8, ecr_param:8;
 #else
-                unsigned long event:16, orig_r8:16;
+                        unsigned long ecr_param:8, ecr_cause:8,
+                                      ecr_vec:8, state:8;
 #endif
-                long orig_r8_word;
+                };
+                unsigned long event;
         };
 
         long user_r25;
@@ -94,11 +103,13 @@ struct callee_regs {
 /* return 1 if PC in delay slot */
 #define delay_mode(regs) ((regs->status32 & STATUS_DE_MASK) == STATUS_DE_MASK)
 
-#define in_syscall(regs)    (regs->event & orig_r8_IS_SCALL)
-#define in_brkpt_trap(regs) (regs->event & orig_r8_IS_BRKPT)
+#define in_syscall(regs)    ((regs->ecr_vec == ECR_V_TRAP) && !regs->ecr_param)
+#define in_brkpt_trap(regs) ((regs->ecr_vec == ECR_V_TRAP) && regs->ecr_param)
 
-#define syscall_wont_restart(regs) (regs->event |= orig_r8_IS_SCALL_RESTARTED)
-#define syscall_restartable(regs) !(regs->event &  orig_r8_IS_SCALL_RESTARTED)
+#define STATE_SCALL_RESTARTED   0x01
+
+#define syscall_wont_restart(reg) (reg->state |= STATE_SCALL_RESTARTED)
+#define syscall_restartable(reg) !(reg->state &  STATE_SCALL_RESTARTED)
 
 #define current_pt_regs()                                       \
 ({                                                              \
@@ -115,11 +126,4 @@ static inline long regs_return_value(struct pt_regs *regs)
 
 #endif /* !__ASSEMBLY__ */
 
-#define orig_r8_IS_SCALL                0x0001
-#define orig_r8_IS_SCALL_RESTARTED      0x0002
-#define orig_r8_IS_BRKPT                0x0004
-#define orig_r8_IS_EXCPN                0x0008
-#define orig_r8_IS_IRQ1                 0x0010
-#define orig_r8_IS_IRQ2                 0x0020
-
 #endif /* __ASM_PTRACE_H */