powerpc/32: Handle bookE debugging in C in exception entry

The handling of SPRN_DBCR0 and other registers can easily
be done in C instead of ASM.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/6d6b2497115890b90cfa72a2b3ab1da5f78123c2.1615552866.git.christophe.leroy@csgroup.eu

diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index c35368a..861e6ea 100644 (file)
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -65,6 +65,8 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup
        if (user_mode(regs))
                account_cpu_user_entry();
 #endif
+
+       booke_restore_dbcr0();
 }
 
 /*

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 0f3f1bd..4ffbcf3 100644 (file)
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -146,32 +146,9 @@ transfer_to_handler:
        addi    r2, r12, -THREAD
        addi    r11,r1,STACK_FRAME_OVERHEAD
        stw     r11,PT_REGS(r12)
-#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
-       /* Check to see if the dbcr0 register is set up to debug.  Use the
-          internal debug mode bit to do this. */
-       lwz     r12,THREAD_DBCR0(r12)
-       andis.  r12,r12,DBCR0_IDM@h
-#endif
 #ifdef CONFIG_PPC_BOOK3S_32
        kuep_lock r11, r12
 #endif
-#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
-       beq+    3f
-       /* From user and task is ptraced - load up global dbcr0 */
-       li      r12,-1                  /* clear all pending debug events */
-       mtspr   SPRN_DBSR,r12
-       lis     r11,global_dbcr0@ha
-       tophys_novmstack r11,r11
-       addi    r11,r11,global_dbcr0@l
-#ifdef CONFIG_SMP
-       lwz     r9,TASK_CPU(r2)
-       slwi    r9,r9,2
-       add     r11,r11,r9
-#endif
-       lwz     r12,0(r11)
-       mtspr   SPRN_DBCR0,r12
-#endif
-
        b       3f
 
 2:     /* if from kernel, check interrupted DOZE/NAP mode and