[PATCH v5 21/22] powerpc/32: Remove the counter in global_dbcr0

Christophe Leroy
2021-02-08T16:35:43Z

global_dbcr0 has two parts, 4 bytes to save/restore the
value of SPRN_DBCR0, and 4 bytes that are incremented/decremented
everytime something is saving/loading the above value.

This counter is only incremented/decremented, its value is never
used and never read.

Remove the counter and devide the size of global_dbcr0 by 2.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
v5: New
---
arch/powerpc/kernel/entry_32.S | 12 +++---------
arch/powerpc/kernel/head_32.h | 3 ---
arch/powerpc/kernel/head_booke.h | 5 +----
3 files changed, 4 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 7c824e8928d0..a574201b0eb6 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -175,14 +175,11 @@ transfer_to_handler:
addi r11,r11,global_dbcr0@l
#ifdef CONFIG_SMP
lwz r9,TASK_CPU(r2)
- slwi r9,r9,3
+ slwi r9,r9,2
add r11,r11,r9
#endif
lwz r12,0(r11)
mtspr SPRN_DBCR0,r12
- lwz r12,4(r11)
- addi r12,r12,-1
- stw r12,4(r11)
#endif

b 3f
@@ -980,14 +977,11 @@ load_dbcr0:
addi r11,r11,global_dbcr0@l
#ifdef CONFIG_SMP
lwz r9,TASK_CPU(r2)
- slwi r9,r9,3
+ slwi r9,r9,2
add r11,r11,r9
#endif
stw r10,0(r11)
mtspr SPRN_DBCR0,r0
- lwz r10,4(r11)
- addi r10,r10,1
- stw r10,4(r11)
li r11,-1
mtspr SPRN_DBSR,r11 /* clear all pending debug events */
blr
@@ -996,7 +990,7 @@ load_dbcr0:
.align 4
.global global_dbcr0
global_dbcr0:
- .space 8*NR_CPUS
+ .space 4*NR_CPUS
.previous
#endif /* !(CONFIG_4xx || CONFIG_BOOKE) */

diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 282d8fd443a9..5001c6ecc3ec 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -166,9 +166,6 @@
addi r11,r11,global_dbcr0@l
lwz r12,0(r11)
mtspr SPRN_DBCR0,r12
- lwz r12,4(r11)
- addi r12,r12,-1
- stw r12,4(r11)
3:
#endif
b transfer_to_syscall /* jump to handler */
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index bfbd240cc8a2..5f565232b99d 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -142,14 +142,11 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
addi r11,r11,global_dbcr0@l
#ifdef CONFIG_SMP
lwz r10, TASK_CPU(r2)
- slwi r10, r10, 3
+ slwi r10, r10, 2
add r11, r11, r10
#endif
lwz r12,0(r11)
mtspr SPRN_DBCR0,r12
- lwz r12,4(r11)
- addi r12,r12,-1
- stw r12,4(r11)

3:
b transfer_to_syscall /* jump to handler */
--
2.25.0