ARC: pt_regs update #4: r25 saved/restored unconditionally

[cascardo/linux.git] / arch / arc / include / asm / entry.h

diff --git a/arch/arc/include/asm/entry.h b/arch/arc/include/asm/entry.h
index 2cf6aa0..72a7ed4 100644 (file)
--- a/arch/arc/include/asm/entry.h
+++ b/arch/arc/include/asm/entry.h
@@ -102,6 +102,10 @@
        POP     r2
        POP     r1
        POP     r0
+
+#ifdef CONFIG_ARC_CURR_IN_REG
+       ld      r25, [sp, 12]
+#endif
 .endm
 
 /*--------------------------------------------------------------
@@ -138,6 +142,7 @@
        POP     r13
 .endm
 
+#define OFF_USER_R25_FROM_R24  (SZ_CALLEE_REGS + SZ_PT_REGS - 8)/4
 
 /*--------------------------------------------------------------
  * Collect User Mode callee regs as struct callee_regs - needed by
@@ -155,7 +160,7 @@
 
 #ifdef CONFIG_ARC_CURR_IN_REG
        ; Retrieve orig r25 and save it on stack
-       ld      r12, [r25, TASK_THREAD + THREAD_USER_R25]
+       ld.as   r12, [sp, OFF_USER_R25_FROM_R24]
        st.a    r12, [sp, -4]
 #else
        PUSH    r25
@@ -204,7 +209,7 @@
 
 #ifdef CONFIG_ARC_CURR_IN_REG
        ld.ab   r12, [sp, 4]
-       st      r12, [r25, TASK_THREAD + THREAD_USER_R25]
+       st.as   r12, [sp, OFF_USER_R25_FROM_R24]
 #else
        POP     r25
 #endif
@@ -218,13 +223,6 @@
        add     sp, sp, SZ_CALLEE_REGS
 .endm
 
-/*--------------------------------------------------------------
- * Restore User mode r25 saved in task_struct->thread.user_r25
- *-------------------------------------------------------------*/
-.macro RESTORE_USER_R25
-       ld  r25, [r25, TASK_THREAD + THREAD_USER_R25]
-.endm
-
 /*-------------------------------------------------------------
  * given a tsk struct, get to the base of it's kernel mode stack
  * tsk->thread_info is really a PAGE, whose bottom hoists stack
@@ -297,22 +295,21 @@
 
        GET_CURR_TASK_ON_CPU   r9
 
-#ifdef CONFIG_ARC_CURR_IN_REG
-
-       /* If current task pointer cached in r25, time to
-        *  -safekeep USER r25 in task->thread_struct->user_r25
-        *  -load r25 with current task ptr
-        */
-       st.as   r25, [r9, (TASK_THREAD + THREAD_USER_R25)/4]
-       mov     r25, r9
-#endif
-
        /* With current tsk in r9, get it's kernel mode stack base */
        GET_TSK_STACK_BASE  r9, r9
 
 66:
+#ifdef CONFIG_ARC_CURR_IN_REG
+       /*
+        * Treat r25 as scratch reg, save it on stack first
+        * Load it with current task pointer
+        */
+       st      r25, [r9, -4]
+       GET_CURR_TASK_ON_CPU   r25
+#endif
+
        /* Save Pre Intr/Exception User SP on kernel stack */
-       st.a    sp, [r9, -12]   ; Make room for orig_r0 and orig_r8
+       st.a    sp, [r9, -16]   ; Make room for orig_r0, orig_r8, user_r25
 
        /* CAUTION:
         * SP should be set at the very end when we are done with everything
@@ -466,7 +463,7 @@
        RESTORE_R12_TO_R0
 
        ld  sp, [sp] /* restore original sp */
-       /* orig_r0 and orig_r8 skipped automatically */
+       /* orig_r0, orig_r8, user_r25 skipped automatically */
 .endm
 
 
@@ -549,7 +546,7 @@
        RESTORE_R12_TO_R0
 
        ld  sp, [sp] /* restore original sp */
-       /* orig_r0 and orig_r8 skipped automatically */
+       /* orig_r0, orig_r8, user_r25 skipped automatically */
 .endm
 
 .macro RESTORE_ALL_INT2
@@ -568,7 +565,7 @@
        RESTORE_R12_TO_R0
 
        ld  sp, [sp] /* restore original sp */
-       /* orig_r0 and orig_r8 skipped automatically */
+       /* orig_r0, orig_r8, user_r25 skipped automatically */
 .endm