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-rw-r--r--arch/arm/common/Makefile2
-rw-r--r--arch/arm/common/mcpm_head.S41
-rw-r--r--arch/arm/kernel/asm-offsets.c1
3 files changed, 38 insertions, 6 deletions
diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
index b070671033ae..9ec273188ccb 100644
--- a/arch/arm/common/Makefile
+++ b/arch/arm/common/Makefile
@@ -11,4 +11,4 @@ obj-$(CONFIG_SHARP_PARAM) += sharpsl_param.o
obj-$(CONFIG_SHARP_SCOOP) += scoop.o
obj-$(CONFIG_PCI_HOST_ITE8152) += it8152.o
obj-$(CONFIG_ARM_TIMER_SP804) += timer-sp.o
-obj-$(CONFIG_MCPM) += mcpm_head.o mcpm_entry.o
+obj-$(CONFIG_MCPM) += mcpm_head.o mcpm_entry.o vlock.o
diff --git a/arch/arm/common/mcpm_head.S b/arch/arm/common/mcpm_head.S
index 7d729bd72674..8178705c4b24 100644
--- a/arch/arm/common/mcpm_head.S
+++ b/arch/arm/common/mcpm_head.S
@@ -16,6 +16,8 @@
#include <linux/linkage.h>
#include <asm/mcpm.h>
+#include "vlock.h"
+
.if MCPM_SYNC_CLUSTER_CPUS
.error "cpus must be the first member of struct mcpm_sync_struct"
.endif
@@ -69,10 +71,11 @@ ENTRY(mcpm_entry_point)
* position independent way.
*/
adr r5, 3f
- ldmia r5, {r6, r7, r8}
+ ldmia r5, {r6, r7, r8, r11}
add r6, r5, r6 @ r6 = mcpm_entry_vectors
ldr r7, [r5, r7] @ r7 = mcpm_power_up_setup_phys
add r8, r5, r8 @ r8 = mcpm_sync
+ add r11, r5, r11 @ r11 = first_man_locks
mov r0, #MCPM_SYNC_CLUSTER_SIZE
mla r8, r0, r10, r8 @ r8 = sync cluster base
@@ -86,13 +89,22 @@ ENTRY(mcpm_entry_point)
@ At this point, the cluster cannot unexpectedly enter the GOING_DOWN
@ state, because there is at least one active CPU (this CPU).
- @ Note: the following is racy as another CPU might be testing
- @ the same flag at the same moment. That'll be fixed later.
+ mov r0, #VLOCK_SIZE
+ mla r11, r0, r10, r11 @ r11 = cluster first man lock
+ mov r0, r11
+ mov r1, r9 @ cpu
+ bl vlock_trylock @ implies DMB
+
+ cmp r0, #0 @ failed to get the lock?
+ bne mcpm_setup_wait @ wait for cluster setup if so
+
ldrb r0, [r8, #MCPM_SYNC_CLUSTER_CLUSTER]
cmp r0, #CLUSTER_UP @ cluster already up?
bne mcpm_setup @ if not, set up the cluster
- @ Otherwise, skip setup:
+ @ Otherwise, release the first man lock and skip setup:
+ mov r0, r11
+ bl vlock_unlock
b mcpm_setup_complete
mcpm_setup:
@@ -142,6 +154,19 @@ mcpm_setup_leave:
dsb
sev
+ mov r0, r11
+ bl vlock_unlock @ implies DMB
+ b mcpm_setup_complete
+
+ @ In the contended case, non-first men wait here for cluster setup
+ @ to complete:
+mcpm_setup_wait:
+ ldrb r0, [r8, #MCPM_SYNC_CLUSTER_CLUSTER]
+ cmp r0, #CLUSTER_UP
+ wfene
+ bne mcpm_setup_wait
+ dmb
+
mcpm_setup_complete:
@ If a platform-specific CPU setup hook is needed, it is
@ called from here.
@@ -173,11 +198,17 @@ mcpm_entry_gated:
3: .word mcpm_entry_vectors - .
.word mcpm_power_up_setup_phys - 3b
.word mcpm_sync - 3b
+ .word first_man_locks - 3b
ENDPROC(mcpm_entry_point)
.bss
- .align 5
+
+ .align CACHE_WRITEBACK_ORDER
+ .type first_man_locks, #object
+first_man_locks:
+ .space VLOCK_SIZE * MAX_NR_CLUSTERS
+ .align CACHE_WRITEBACK_ORDER
.type mcpm_entry_vectors, #object
ENTRY(mcpm_entry_vectors)
diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
index 1bed82a0a9e0..3f088225e71c 100644
--- a/arch/arm/kernel/asm-offsets.c
+++ b/arch/arm/kernel/asm-offsets.c
@@ -150,6 +150,7 @@ int main(void)
DEFINE(DMA_TO_DEVICE, DMA_TO_DEVICE);
DEFINE(DMA_FROM_DEVICE, DMA_FROM_DEVICE);
BLANK();
+ DEFINE(CACHE_WRITEBACK_ORDER, __CACHE_WRITEBACK_ORDER);
DEFINE(CACHE_WRITEBACK_GRANULE, __CACHE_WRITEBACK_GRANULE);
BLANK();
#ifdef CONFIG_KVM_ARM_HOST