microblaze: Save and restore r3/r4 in SAVE/RESTORE_REGS macros

Save and restore R3/R4 registers in macros. This change
help to cleanup entry.S.

In ret_from_trap function we are saving returning value from
syscall to pt_regs on stack that's why we don't need to save and
restore these values before kernel functions (schedule, do_signal).

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

1 files changed, 8 insertions, 40 deletions

diff --git a/arch/microblaze/kernel/entry.S b/arch/microblaze/kernel/entry.S
index d40a59f9db4b..8f90ce7ecb6c 100644
--- a/arch/microblaze/kernel/entry.S
+++ b/arch/microblaze/kernel/entry.S
@@ -194,6 +194,8 @@
 
 #define SAVE_REGS \
         swi     r2, r1, PTO+PT_R2;      /* Save SDA */                  \
+        swi     r3, r1, PTO+PT_R3;                                      \
+        swi     r4, r1, PTO+PT_R4;                                      \
         swi     r5, r1, PTO+PT_R5;                                      \
         swi     r6, r1, PTO+PT_R6;                                      \
         swi     r7, r1, PTO+PT_R7;                                      \
@@ -228,6 +230,8 @@
         mts     rmsr , r11;                                             \
         nop;                                                            \
         lwi     r2, r1, PTO+PT_R2;      /* restore SDA */               \
+        lwi     r3, r1, PTO+PT_R3;                                      \
+        lwi     r4, r1, PTO+PT_R4;                                      \
         lwi     r5, r1, PTO+PT_R5;                                      \
         lwi     r6, r1, PTO+PT_R6;                                      \
         lwi     r7, r1, PTO+PT_R7;                                      \
@@ -379,13 +383,12 @@ C_ENTRY(_user_exception):
 /* We re-enable BIP bit before state restore */
 C_ENTRY(ret_from_trap):
         set_bip;                        /*  Ints masked for state restore*/
-        lwi     r11, r1, PTO+PT_MODE;
-/* 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
 
+        lwi     r11, r1, PTO+PT_MODE;
+/* See if returning to kernel mode, if so, skip resched &c.  */
+        bnei    r11, 2f;
         /* We're returning to user mode, so check for various conditions that
          * trigger rescheduling. */
         /* FIXME: Restructure all these flag checks. */
@@ -422,9 +425,6 @@ C_ENTRY(ret_from_trap):
 
 /* Finally, return to user state.  */
 1:
-        lwi     r3, r1, PTO + PT_R3; /* restore syscall result */
-        lwi     r4, r1, PTO + PT_R4;
-
         swi     r0, r0, PER_CPU(KM);    /* Now officially in user state. */
         swi     CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */
         VM_OFF;
@@ -522,10 +522,6 @@ C_ENTRY(sys_rt_sigreturn_wrapper):
         swi     r11, r1, (PT_R1-PT_SIZE); /* Save original SP. */       \
         lwi     r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */\
         addik   r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack.  */\
-        /* store return registers separately because                    \
-         * this macros is use for others exceptions */                  \
-        swi     r3, r1, PTO + PT_R3;                                    \
-        swi     r4, r1, PTO + PT_R4;                                    \
         SAVE_REGS                                                       \
         /* PC, before IRQ/trap - this is one instruction above */       \
         swi     r17, r1, PTO+PT_PC;                                     \
@@ -543,10 +539,6 @@ C_ENTRY(sys_rt_sigreturn_wrapper):
         tophys(r1,r1);                                                  \
                                                                         \
         addik   r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack.  */\
-        /* store return registers separately because this macros        \
-         * is use for others exceptions */                              \
-        swi     r3, r1, PTO + PT_R3;                                    \
-        swi     r4, r1, PTO + PT_R4;                                    \
         SAVE_REGS                                                       \
         /* PC, before IRQ/trap - this is one instruction above FIXME*/  \
         swi     r17, r1, PTO+PT_PC;                                     \
@@ -689,9 +681,7 @@ C_ENTRY(ret_from_exc):
          * traps), but signal handlers may want to examine or change the
          * complete register state.  Here we save anything not saved by
          * the normal entry sequence, so that it may be safely restored
-         * (in a possibly modified form) after do_signal returns.
-         * store return registers separately because this macros is use
-         * for others exceptions */
+         * (in a possibly modified form) after do_signal returns. */
         la      r5, r1, PTO;            /* Arg 1: struct pt_regs *regs */
         addi    r7, r0, 0;              /* Arg 3: int in_syscall */
         bralid  r15, do_signal; /* Handle any signals */
@@ -703,8 +693,6 @@ C_ENTRY(ret_from_exc):
         VM_OFF;
         tophys(r1,r1);
 
-        lwi     r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
-        lwi     r4, r1, PTO+PT_R4;
         RESTORE_REGS;
         addik   r1, r1, STATE_SAVE_SIZE         /* Clean up stack space.  */
 
@@ -713,8 +701,6 @@ C_ENTRY(ret_from_exc):
 /* Return to kernel state.  */
 2:      VM_OFF;
         tophys(r1,r1);
-        lwi     r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
-        lwi     r4, r1, PTO+PT_R4;
         RESTORE_REGS;
         addik   r1, r1, STATE_SAVE_SIZE         /* Clean up stack space.  */
 
@@ -753,10 +739,6 @@ C_ENTRY(_interrupt):
         /* save registers */
 /* MS: Make room on the stack -> activation record */
         addik   r1, r1, -STATE_SAVE_SIZE;
-/* MS: store return registers separately because
- * this macros is use for others exceptions */
-        swi     r3, r1, PTO + PT_R3;
-        swi     r4, r1, PTO + PT_R4;
         SAVE_REGS
         /* MS: store mode */
         addi    r11, r0, 1; /* MS: Was in kernel-mode. */
@@ -776,8 +758,6 @@ C_ENTRY(_interrupt):
         tophys(r1,r1);
         /* save registers */
         addik   r1, r1, -STATE_SAVE_SIZE;
-        swi     r3, r1, PTO+PT_R3;
-        swi     r4, r1, PTO+PT_R4;
         SAVE_REGS
         /* calculate mode */
         swi     r0, r1, PTO + PT_MODE;
@@ -829,8 +809,6 @@ no_intr_resched:
         swi     CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE);
         VM_OFF;
         tophys(r1,r1);
-        lwi     r3, r1, PTO + PT_R3; /* MS: restore saved r3, r4 registers */
-        lwi     r4, r1, PTO + PT_R4;
         RESTORE_REGS
         addik   r1, r1, STATE_SAVE_SIZE /* MS: Clean up stack space. */
         lwi     r1, r1, PT_R1 - PT_SIZE;
@@ -859,8 +837,6 @@ restore:
 #endif
         VM_OFF /* MS: turn off MMU */
         tophys(r1,r1)
-        lwi     r3, r1, PTO + PT_R3; /* MS: restore saved r3, r4 registers */
-        lwi     r4, r1, PTO + PT_R4;
         RESTORE_REGS
         addik   r1, r1, STATE_SAVE_SIZE /* MS: Clean up stack space. */
         tovirt(r1,r1);
@@ -893,8 +869,6 @@ C_ENTRY(_debug_exception):
         lwi     r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */
 
         addik   r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack.  */
-        swi     r3, r1, PTO + PT_R3;
-        swi     r4, r1, PTO + PT_R4;
         SAVE_REGS;
 
         addi    r11, r0, 1;             /* Was in kernel-mode.  */
@@ -910,8 +884,6 @@ C_ENTRY(_debug_exception):
         tophys(r1,r1);
 
         addik   r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack.  */
-        swi     r3, r1, PTO + PT_R3;
-        swi     r4, r1, PTO + PT_R4;
         SAVE_REGS;
 
         swi     r0, r1, PTO+PT_MODE; /* Was in user-mode.  */
@@ -979,8 +951,6 @@ dbtrap_call:	rtbd	r11, 0;
         VM_OFF;
         tophys(r1,r1);
 
-        lwi     r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
-        lwi     r4, r1, PTO+PT_R4;
         RESTORE_REGS
         addik   r1, r1, STATE_SAVE_SIZE         /* Clean up stack space.  */
 
@@ -992,8 +962,6 @@ dbtrap_call:	rtbd	r11, 0;
 /* Return to kernel state.  */
 2:      VM_OFF;
         tophys(r1,r1);
-        lwi     r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
-        lwi     r4, r1, PTO+PT_R4;
         RESTORE_REGS
         addik   r1, r1, STATE_SAVE_SIZE         /* Clean up stack space.  */