[POWERPC] Make Book-E debug handling SMP safe

global_dbcr0 needs to be a per cpu set of save areas instead of a single
global on all processors.

Also, we switch to using DBCR0_IDM to determine if the user space app is
being debugged as its a more consistent way.  In the future we should
support features like hardware breakpoint and watchpoints which will
have DBCR0_IDM set but not necessarily DBCR0_IC (single step).

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 69a91bd46115e171bb73cf76282db673ce5d054e..84c8686330681761ea173c2a11d56e74f4f6848a 100644 (file)
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -110,9 +110,9 @@ transfer_to_handler:
        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
-          single-step bit to do this. */
+          internal debug mode bit to do this. */
        lwz     r12,THREAD_DBCR0(r12)
-       andis.  r12,r12,DBCR0_IC@h
+       andis.  r12,r12,DBCR0_IDM@h
        beq+    3f
        /* From user and task is ptraced - load up global dbcr0 */
        li      r12,-1                  /* clear all pending debug events */
@@ -120,6 +120,12 @@ transfer_to_handler:
        lis     r11,global_dbcr0@ha
        tophys(r11,r11)
        addi    r11,r11,global_dbcr0@l
+#ifdef CONFIG_SMP
+       rlwinm  r9,r1,0,0,(31-THREAD_SHIFT)
+       lwz     r9,TI_CPU(r9)
+       slwi    r9,r9,3
+       add     r11,r11,r9
+#endif
        lwz     r12,0(r11)
        mtspr   SPRN_DBCR0,r12
        lwz     r12,4(r11)
@@ -238,10 +244,10 @@ ret_from_syscall:
        stw     r11,_CCR(r1)
 syscall_exit_cont:
 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
-       /* If the process has its own DBCR0 value, load it up.  The single
-          step bit tells us that dbcr0 should be loaded. */
+       /* If the process has its own DBCR0 value, load it up.  The internal
+          debug mode bit tells us that dbcr0 should be loaded. */
        lwz     r0,THREAD+THREAD_DBCR0(r2)
-       andis.  r10,r0,DBCR0_IC@h
+       andis.  r10,r0,DBCR0_IDM@h
        bnel-   load_dbcr0
 #endif
 #ifdef CONFIG_44x
@@ -666,10 +672,10 @@ user_exc_return:          /* r10 contains MSR_KERNEL here */
 
 restore_user:
 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
-       /* Check whether this process has its own DBCR0 value.  The single
-          step bit tells us that dbcr0 should be loaded. */
+       /* Check whether this process has its own DBCR0 value.  The internal
+          debug mode bit tells us that dbcr0 should be loaded. */
        lwz     r0,THREAD+THREAD_DBCR0(r2)
-       andis.  r10,r0,DBCR0_IC@h
+       andis.  r10,r0,DBCR0_IDM@h
        bnel-   load_dbcr0
 #endif
 
@@ -879,6 +885,12 @@ load_dbcr0:
        mfspr   r10,SPRN_DBCR0
        lis     r11,global_dbcr0@ha
        addi    r11,r11,global_dbcr0@l
+#ifdef CONFIG_SMP
+       rlwinm  r9,r1,0,0,(31-THREAD_SHIFT)
+       lwz     r9,TI_CPU(r9)
+       slwi    r9,r9,3
+       add     r11,r11,r9
+#endif
        stw     r10,0(r11)
        mtspr   SPRN_DBCR0,r0
        lwz     r10,4(r11)
@@ -891,7 +903,7 @@ load_dbcr0:
        .section .bss
        .align  4
 global_dbcr0:
-       .space  8
+       .space  8*NR_CPUS
        .previous
 #endif /* !(CONFIG_4xx || CONFIG_BOOKE) */