powerpc: Rearrange head_64.S to move interrupt handler code to the beginning

This rearranges head_64.S so that we have all the first-level exception
prologs together starting at 0x100, followed by all the second-level
handlers that are invoked from the first-level prologs, followed by
other code.  This doesn't make any functional change but will make
following changes for relocatable kernel support easier.

Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 106 insertions, 97 deletions

diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index cc8fb474d52..27935d1ab6a 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -325,16 +325,32 @@ do_stab_bolted_pSeries:
         mfspr   r12,SPRN_SPRG2
         EXCEPTION_PROLOG_PSERIES(PACA_EXSLB, .do_stab_bolted)
 
+#ifdef CONFIG_PPC_PSERIES
+/*
+ * Vectors for the FWNMI option.  Share common code.
+ */
+        .globl system_reset_fwnmi
+      .align 7
+system_reset_fwnmi:
+        HMT_MEDIUM
+        mtspr   SPRN_SPRG1,r13          /* save r13 */
+        EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common)
+
+        .globl machine_check_fwnmi
+      .align 7
+machine_check_fwnmi:
+        HMT_MEDIUM
+        mtspr   SPRN_SPRG1,r13          /* save r13 */
+        EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common)
+
+#endif /* CONFIG_PPC_PSERIES */
+
+#ifdef __DISABLED__
 /*
- * We have some room here  we use that to put
- * the peries slb miss user trampoline code so it's reasonably
- * away from slb_miss_user_common to avoid problems with rfid
- *
  * This is used for when the SLB miss handler has to go virtual,
  * which doesn't happen for now anymore but will once we re-implement
  * dynamic VSIDs for shared page tables
  */
-#ifdef __DISABLED__
 slb_miss_user_pseries:
         std     r10,PACA_EXGEN+EX_R10(r13)
         std     r11,PACA_EXGEN+EX_R11(r13)
@@ -357,25 +373,14 @@ slb_miss_user_pseries:
         b       .                               /* prevent spec. execution */
 #endif /* __DISABLED__ */
 
-#ifdef CONFIG_PPC_PSERIES
+        .align  7
+        .globl  __end_interrupts
+__end_interrupts:
+
 /*
- * Vectors for the FWNMI option.  Share common code.
+ * Code from here down to __end_handlers is invoked from the
+ * exception prologs above.
  */
-        .globl system_reset_fwnmi
-      .align 7
-system_reset_fwnmi:
-        HMT_MEDIUM
-        mtspr   SPRN_SPRG1,r13          /* save r13 */
-        EXCEPTION_PROLOG_PSERIES_FORCE_64BIT(PACA_EXGEN, system_reset_common)
-
-        .globl machine_check_fwnmi
-      .align 7
-machine_check_fwnmi:
-        HMT_MEDIUM
-        mtspr   SPRN_SPRG1,r13          /* save r13 */
-        EXCEPTION_PROLOG_PSERIES_FORCE_64BIT(PACA_EXMC, machine_check_common)
-
-#endif /* CONFIG_PPC_PSERIES */
 
 /*** Common interrupt handlers ***/
 
@@ -457,65 +462,6 @@ bad_stack:
         b       1b
 
 /*
- * Return from an exception with minimal checks.
- * The caller is assumed to have done EXCEPTION_PROLOG_COMMON.
- * If interrupts have been enabled, or anything has been
- * done that might have changed the scheduling status of
- * any task or sent any task a signal, you should use
- * ret_from_except or ret_from_except_lite instead of this.
- */
-fast_exc_return_irq:                    /* restores irq state too */
-        ld      r3,SOFTE(r1)
-        TRACE_AND_RESTORE_IRQ(r3);
-        ld      r12,_MSR(r1)
-        rldicl  r4,r12,49,63            /* get MSR_EE to LSB */
-        stb     r4,PACAHARDIRQEN(r13)   /* restore paca->hard_enabled */
-        b       1f
-
-        .globl  fast_exception_return
-fast_exception_return:
-        ld      r12,_MSR(r1)
-1:      ld      r11,_NIP(r1)
-        andi.   r3,r12,MSR_RI           /* check if RI is set */
-        beq-    unrecov_fer
-
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
-        andi.   r3,r12,MSR_PR
-        beq     2f
-        ACCOUNT_CPU_USER_EXIT(r3, r4)
-2:
-#endif
-
-        ld      r3,_CCR(r1)
-        ld      r4,_LINK(r1)
-        ld      r5,_CTR(r1)
-        ld      r6,_XER(r1)
-        mtcr    r3
-        mtlr    r4
-        mtctr   r5
-        mtxer   r6
-        REST_GPR(0, r1)
-        REST_8GPRS(2, r1)
-
-        mfmsr   r10
-        rldicl  r10,r10,48,1            /* clear EE */
-        rldicr  r10,r10,16,61           /* clear RI (LE is 0 already) */
-        mtmsrd  r10,1
-
-        mtspr   SPRN_SRR1,r12
-        mtspr   SPRN_SRR0,r11
-        REST_4GPRS(10, r1)
-        ld      r1,GPR1(r1)
-        rfid
-        b       .       /* prevent speculative execution */
-
-unrecov_fer:
-        bl      .save_nvgprs
-1:      addi    r3,r1,STACK_FRAME_OVERHEAD
-        bl      .unrecoverable_exception
-        b       1b
-
-/*
  * Here r13 points to the paca, r9 contains the saved CR,
  * SRR0 and SRR1 are saved in r11 and r12,
  * r9 - r13 are saved in paca->exgen.
@@ -766,6 +712,85 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
         bl      .altivec_unavailable_exception
         b       .ret_from_except
 
+        .align  7
+        .globl vsx_unavailable_common
+vsx_unavailable_common:
+        EXCEPTION_PROLOG_COMMON(0xf40, PACA_EXGEN)
+#ifdef CONFIG_VSX
+BEGIN_FTR_SECTION
+        bne     .load_up_vsx
+1:
+END_FTR_SECTION_IFSET(CPU_FTR_VSX)
+#endif
+        bl      .save_nvgprs
+        addi    r3,r1,STACK_FRAME_OVERHEAD
+        ENABLE_INTS
+        bl      .vsx_unavailable_exception
+        b       .ret_from_except
+
+        .align  7
+        .globl  __end_handlers
+__end_handlers:
+
+/*
+ * Return from an exception with minimal checks.
+ * The caller is assumed to have done EXCEPTION_PROLOG_COMMON.
+ * If interrupts have been enabled, or anything has been
+ * done that might have changed the scheduling status of
+ * any task or sent any task a signal, you should use
+ * ret_from_except or ret_from_except_lite instead of this.
+ */
+fast_exc_return_irq:                    /* restores irq state too */
+        ld      r3,SOFTE(r1)
+        TRACE_AND_RESTORE_IRQ(r3);
+        ld      r12,_MSR(r1)
+        rldicl  r4,r12,49,63            /* get MSR_EE to LSB */
+        stb     r4,PACAHARDIRQEN(r13)   /* restore paca->hard_enabled */
+        b       1f
+
+        .globl  fast_exception_return
+fast_exception_return:
+        ld      r12,_MSR(r1)
+1:      ld      r11,_NIP(r1)
+        andi.   r3,r12,MSR_RI           /* check if RI is set */
+        beq-    unrecov_fer
+
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+        andi.   r3,r12,MSR_PR
+        beq     2f
+        ACCOUNT_CPU_USER_EXIT(r3, r4)
+2:
+#endif
+
+        ld      r3,_CCR(r1)
+        ld      r4,_LINK(r1)
+        ld      r5,_CTR(r1)
+        ld      r6,_XER(r1)
+        mtcr    r3
+        mtlr    r4
+        mtctr   r5
+        mtxer   r6
+        REST_GPR(0, r1)
+        REST_8GPRS(2, r1)
+
+        mfmsr   r10
+        rldicl  r10,r10,48,1            /* clear EE */
+        rldicr  r10,r10,16,61           /* clear RI (LE is 0 already) */
+        mtmsrd  r10,1
+
+        mtspr   SPRN_SRR1,r12
+        mtspr   SPRN_SRR0,r11
+        REST_4GPRS(10, r1)
+        ld      r1,GPR1(r1)
+        rfid
+        b       .       /* prevent speculative execution */
+
+unrecov_fer:
+        bl      .save_nvgprs
+1:      addi    r3,r1,STACK_FRAME_OVERHEAD
+        bl      .unrecoverable_exception
+        b       1b
+
 #ifdef CONFIG_ALTIVEC
 /*
  * load_up_altivec(unused, unused, tsk)
@@ -840,22 +865,6 @@ _STATIC(load_up_altivec)
         blr
 #endif /* CONFIG_ALTIVEC */
 
-        .align  7
-        .globl vsx_unavailable_common
-vsx_unavailable_common:
-        EXCEPTION_PROLOG_COMMON(0xf40, PACA_EXGEN)
-#ifdef CONFIG_VSX
-BEGIN_FTR_SECTION
-        bne     .load_up_vsx
-1:
-END_FTR_SECTION_IFSET(CPU_FTR_VSX)
-#endif
-        bl      .save_nvgprs
-        addi    r3,r1,STACK_FRAME_OVERHEAD
-        ENABLE_INTS
-        bl      .vsx_unavailable_exception
-        b       .ret_from_except
-
 #ifdef CONFIG_VSX
 /*
  * load_up_vsx(unused, unused, tsk)