microblaze: Simplify entry.S - save/restore r3/r4 - ret_from_trap

There is possible to save r3/r4 at the beggining of user part
before calling handlers and at the end restore it.

Signed-off-by: Michal Simek <monstr@monstr.eu>

diff --git a/arch/microblaze/kernel/entry.S b/arch/microblaze/kernel/entry.S
index 1a6729d..772fe74 100644 (file)
--- a/arch/microblaze/kernel/entry.S
+++ b/arch/microblaze/kernel/entry.S
@@ -305,7 +305,7 @@ C_ENTRY(_user_exception):
        swi     r11, r1, PTO+PT_R1;             /* Store user SP.  */
        addi    r11, r0, 1;
        swi     r11, r0, TOPHYS(PER_CPU(KM));   /* Now we're in kernel-mode.  */
-2:     lwi     r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */
+2:     lwi     CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
        /* Save away the syscall number.  */
        swi     r12, r1, PTO+PT_R0;
        tovirt(r1,r1)
@@ -322,8 +322,7 @@ C_ENTRY(_user_exception):
        rtid    r11, 0
        nop
 3:
-       add     r11, r0, CURRENT_TASK    /* Get current task ptr into r11 */
-       lwi     r11, r11, TS_THREAD_INFO /* get thread info */
+       lwi     r11, CURRENT_TASK, TS_THREAD_INFO /* get thread info */
        lwi     r11, r11, TI_FLAGS       /* get flags in thread info */
        andi    r11, r11, _TIF_WORK_SYSCALL_MASK
        beqi    r11, 4f
@@ -382,58 +381,50 @@ C_ENTRY(ret_from_trap):
 /* See if returning to kernel mode, if so, skip resched &c.  */
        bnei    r11, 2f;
 
+       swi     r3, r1, PTO + PT_R3
+       swi     r4, r1, PTO + PT_R4
+
        /* We're returning to user mode, so check for various conditions that
         * trigger rescheduling. */
-       # FIXME: Restructure all these flag checks.
-       add     r11, r0, CURRENT_TASK;  /* Get current task ptr into r11 */
-       lwi     r11, r11, TS_THREAD_INFO;       /* get thread info */
+       /* FIXME: Restructure all these flag checks. */
+       lwi     r11, CURRENT_TASK, TS_THREAD_INFO;      /* get thread info */
        lwi     r11, r11, TI_FLAGS;             /* get flags in thread info */
        andi    r11, r11, _TIF_WORK_SYSCALL_MASK
        beqi    r11, 1f
 
-       swi     r3, r1, PTO + PT_R3
-       swi     r4, r1, PTO + PT_R4
        brlid   r15, do_syscall_trace_leave
        addik   r5, r1, PTO + PT_R0
-       lwi     r3, r1, PTO + PT_R3
-       lwi     r4, r1, PTO + PT_R4
 1:
-
        /* We're returning to user mode, so check for various conditions that
         * trigger rescheduling. */
-       /* Get current task ptr into r11 */
-       add     r11, r0, CURRENT_TASK;  /* Get current task ptr into r11 */
-       lwi     r11, r11, TS_THREAD_INFO;       /* get thread info */
+       /* get thread info from current task */
+       lwi     r11, CURRENT_TASK, TS_THREAD_INFO;
        lwi     r11, r11, TI_FLAGS;             /* get flags in thread info */
        andi    r11, r11, _TIF_NEED_RESCHED;
        beqi    r11, 5f;
 
-       swi     r3, r1, PTO + PT_R3; /* store syscall result */
-       swi     r4, r1, PTO + PT_R4;
        bralid  r15, schedule;  /* Call scheduler */
        nop;                            /* delay slot */
-       lwi     r3, r1, PTO + PT_R3; /* restore syscall result */
-       lwi     r4, r1, PTO + PT_R4;
 
        /* Maybe handle a signal */
-5:     add     r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */
-       lwi     r11, r11, TS_THREAD_INFO;       /* get thread info */
+5:     /* get thread info from current task*/
+       lwi     r11, CURRENT_TASK, TS_THREAD_INFO;
        lwi     r11, r11, TI_FLAGS;     /* get flags in thread info */
        andi    r11, r11, _TIF_SIGPENDING;
        beqi    r11, 1f;                /* Signals to handle, handle them */
 
-       swi     r3, r1, PTO + PT_R3; /* store syscall result */
-       swi     r4, r1, PTO + PT_R4;
        la      r5, r1, PTO;            /* Arg 1: struct pt_regs *regs */
        add     r6, r0, r0;             /* Arg 2: sigset_t *oldset */
        addi    r7, r0, 1;              /* Arg 3: int in_syscall */
        bralid  r15, do_signal; /* Handle any signals */
        nop;
+
+/* Finally, return to user state.  */
+1:
        lwi     r3, r1, PTO + PT_R3; /* restore syscall result */
        lwi     r4, r1, PTO + PT_R4;
 
-/* Finally, return to user state.  */
-1:     swi     r0, r0, PER_CPU(KM);    /* Now officially in user state. */
+       swi     r0, r0, PER_CPU(KM);    /* Now officially in user state. */
        add     r11, r0, CURRENT_TASK;  /* Get current task ptr into r11 */
        swi     r11, r0, PER_CPU(CURRENT_SAVE); /* save current */
        VM_OFF;
@@ -565,7 +556,7 @@ C_ENTRY(sys_rt_sigreturn_wrapper):
        swi     r11, r1, PTO+PT_R1; /* Store user SP.  */               \
        addi    r11, r0, 1;                                             \
        swi     r11, r0, TOPHYS(PER_CPU(KM)); /* Now we're in kernel-mode.*/\
-2:     lwi     r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */\
+2:     lwi     CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE));        \
        /* Save away the syscall number.  */                            \
        swi     r0, r1, PTO+PT_R0;                                      \
        tovirt(r1,r1)
@@ -673,9 +664,7 @@ C_ENTRY(ret_from_exc):
 
        /* We're returning to user mode, so check for various conditions that
           trigger rescheduling. */
-       /* Get current task ptr into r11 */
-       add     r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */
-       lwi     r11, r11, TS_THREAD_INFO;       /* get thread info */
+       lwi     r11, CURRENT_TASK, TS_THREAD_INFO;      /* get thread info */
        lwi     r11, r11, TI_FLAGS;     /* get flags in thread info */
        andi    r11, r11, _TIF_NEED_RESCHED;
        beqi    r11, 5f;
@@ -685,8 +674,7 @@ C_ENTRY(ret_from_exc):
        nop;                            /* delay slot */
 
        /* Maybe handle a signal */
-5:     add     r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */
-       lwi     r11, r11, TS_THREAD_INFO;       /* get thread info */
+5:     lwi     r11, CURRENT_TASK, TS_THREAD_INFO;      /* get thread info */
        lwi     r11, r11, TI_FLAGS;     /* get flags in thread info */
        andi    r11, r11, _TIF_SIGPENDING;
        beqi    r11, 1f;                /* Signals to handle, handle them */
@@ -802,7 +790,7 @@ C_ENTRY(_interrupt):
        swi     r11, r0, TOPHYS(PER_CPU(KM));
 
 2:
-       lwi     r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
+       lwi     CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
        swi     r0, r1, PTO + PT_R0;
        tovirt(r1,r1)
        la      r5, r1, PTO;
@@ -817,8 +805,7 @@ ret_from_irq:
        lwi     r11, r1, PTO + PT_MODE;
        bnei    r11, 2f;
 
-       add     r11, r0, CURRENT_TASK;
-       lwi     r11, r11, TS_THREAD_INFO;
+       lwi     r11, CURRENT_TASK, TS_THREAD_INFO;
        lwi     r11, r11, TI_FLAGS; /* MS: get flags from thread info */
        andi    r11, r11, _TIF_NEED_RESCHED;
        beqi    r11, 5f
@@ -826,8 +813,7 @@ ret_from_irq:
        nop; /* delay slot */
 
     /* Maybe handle a signal */
-5:     add     r11, r0, CURRENT_TASK;
-       lwi     r11, r11, TS_THREAD_INFO; /* MS: get thread info */
+5:     lwi     r11, CURRENT_TASK, TS_THREAD_INFO; /* MS: get thread info */
        lwi     r11, r11, TI_FLAGS; /* get flags in thread info */
        andi    r11, r11, _TIF_SIGPENDING;
        beqid   r11, no_intr_resched
@@ -855,8 +841,7 @@ no_intr_resched:
 /* MS: Return to kernel state. */
 2:
 #ifdef CONFIG_PREEMPT
-       add     r11, r0, CURRENT_TASK;
-       lwi     r11, r11, TS_THREAD_INFO;
+       lwi     r11, CURRENT_TASK, TS_THREAD_INFO;
        /* MS: get preempt_count from thread info */
        lwi     r5, r11, TI_PREEMPT_COUNT;
        bgti    r5, restore;
@@ -869,8 +854,7 @@ preempt:
        /* interrupts are off that's why I am calling preempt_chedule_irq */
        bralid  r15, preempt_schedule_irq
        nop
-       add     r11, r0, CURRENT_TASK;  /* Get current task ptr into r11 */
-       lwi     r11, r11, TS_THREAD_INFO;       /* get thread info */
+       lwi     r11, CURRENT_TASK, TS_THREAD_INFO;      /* get thread info */
        lwi     r5, r11, TI_FLAGS;              /* get flags in thread info */
        andi    r5, r5, _TIF_NEED_RESCHED;
        bnei    r5, preempt /* if non zero jump to resched */
@@ -938,7 +922,7 @@ C_ENTRY(_debug_exception):
        swi     r11, r1, PTO+PT_R1; /* Store user SP.  */
        addi    r11, r0, 1;
        swi     r11, r0, TOPHYS(PER_CPU(KM));   /* Now we're in kernel-mode.  */
-2:     lwi     r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */
+2:     lwi     CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
        /* Save away the syscall number.  */
        swi     r0, r1, PTO+PT_R0;
        tovirt(r1,r1)
@@ -958,8 +942,7 @@ dbtrap_call:        rtbd    r11, 0;
        bnei    r11, 2f;
 
        /* Get current task ptr into r11 */
-       add     r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */
-       lwi     r11, r11, TS_THREAD_INFO;       /* get thread info */
+       lwi     r11, CURRENT_TASK, TS_THREAD_INFO;      /* get thread info */
        lwi     r11, r11, TI_FLAGS;     /* get flags in thread info */
        andi    r11, r11, _TIF_NEED_RESCHED;
        beqi    r11, 5f;
@@ -972,8 +955,7 @@ dbtrap_call:        rtbd    r11, 0;
        /* XXX m68knommu also checks TASK_STATE & TASK_COUNTER here.  */
 
        /* Maybe handle a signal */
-5:     add     r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */
-       lwi     r11, r11, TS_THREAD_INFO;       /* get thread info */
+5:     lwi     r11, CURRENT_TASK, TS_THREAD_INFO;      /* get thread info */
        lwi     r11, r11, TI_FLAGS;     /* get flags in thread info */
        andi    r11, r11, _TIF_SIGPENDING;
        beqi    r11, 1f;                /* Signals to handle, handle them */
@@ -1030,7 +1012,7 @@ DBTRAP_return:            /* Make global symbol for debugging */
 
 ENTRY(_switch_to)
        /* prepare return value */
-       addk    r3, r0, r31
+       addk    r3, r0, CURRENT_TASK
 
        /* save registers in cpu_context */
        /* use r11 and r12, volatile registers, as temp register */
@@ -1074,10 +1056,10 @@ ENTRY(_switch_to)
        nop
        swi     r12, r11, CC_FSR
 
-       /* update r31, the current */
-       lwi     r31, r6, TI_TASK/* give me pointer to task which will be next */
+       /* update r31, the current-give me pointer to task which will be next */
+       lwi     CURRENT_TASK, r6, TI_TASK
        /* stored it to current_save too */
-       swi     r31, r0, PER_CPU(CURRENT_SAVE)
+       swi     CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE)
 
        /* get new process' cpu context and restore */
        /* give me start where start context of next task */