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authorNicolas Pitre <nicolas.pitre@linaro.org>2012-11-27 23:11:20 -0500
committerNicolas Pitre <nicolas.pitre@linaro.org>2013-09-23 18:47:27 -0400
commitde885d147ad2c4a66777e3557440247efde1cc8d (patch)
tree9e10c47ffec8f627809fa7825a5f948f40892b5d
parent5135d875e1457ef946a055003d8f80713e862135 (diff)
ARM: mcpm: add a simple poke mechanism to the early entry code
This allows to poke a predetermined value into a specific address upon entering the early boot code in bL_head.S. Signed-off-by: Nicolas Pitre <nico@linaro.org>
-rw-r--r--arch/arm/common/mcpm_entry.c12
-rw-r--r--arch/arm/common/mcpm_head.S16
-rw-r--r--arch/arm/include/asm/mcpm.h8
3 files changed, 34 insertions, 2 deletions
diff --git a/arch/arm/common/mcpm_entry.c b/arch/arm/common/mcpm_entry.c
index 370236dd1a03..4a2b32fd53a1 100644
--- a/arch/arm/common/mcpm_entry.c
+++ b/arch/arm/common/mcpm_entry.c
@@ -27,6 +27,18 @@ void mcpm_set_entry_vector(unsigned cpu, unsigned cluster, void *ptr)
sync_cache_w(&mcpm_entry_vectors[cluster][cpu]);
}
+extern unsigned long mcpm_entry_early_pokes[MAX_NR_CLUSTERS][MAX_CPUS_PER_CLUSTER][2];
+
+void mcpm_set_early_poke(unsigned cpu, unsigned cluster,
+ unsigned long poke_phys_addr, unsigned long poke_val)
+{
+ unsigned long *poke = &mcpm_entry_early_pokes[cluster][cpu][0];
+ poke[0] = poke_phys_addr;
+ poke[1] = poke_val;
+ __cpuc_flush_dcache_area((void *)poke, 8);
+ outer_clean_range(__pa(poke), __pa(poke + 2));
+}
+
static const struct mcpm_platform_ops *platform_ops;
int __init mcpm_platform_register(const struct mcpm_platform_ops *ops)
diff --git a/arch/arm/common/mcpm_head.S b/arch/arm/common/mcpm_head.S
index 39c96df3477a..49dd5352fe70 100644
--- a/arch/arm/common/mcpm_head.S
+++ b/arch/arm/common/mcpm_head.S
@@ -71,12 +71,19 @@ ENTRY(mcpm_entry_point)
* position independent way.
*/
adr r5, 3f
- ldmia r5, {r6, r7, r8, r11}
+ ldmia r5, {r0, r6, r7, r8, r11}
+ add r0, r5, r0 @ r0 = mcpm_entry_early_pokes
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
+ @ Perform an early poke, if any
+ add r0, r0, r4, lsl #3
+ ldmia r0, {r0, r1}
+ teq r0, #0
+ strne r1, [r0]
+
mov r0, #MCPM_SYNC_CLUSTER_SIZE
mla r8, r0, r10, r8 @ r8 = sync cluster base
@@ -195,7 +202,8 @@ mcpm_entry_gated:
.align 2
-3: .word mcpm_entry_vectors - .
+3: .word mcpm_entry_early_pokes - .
+ .word mcpm_entry_vectors - 3b
.word mcpm_power_up_setup_phys - 3b
.word mcpm_sync - 3b
.word first_man_locks - 3b
@@ -214,6 +222,10 @@ first_man_locks:
ENTRY(mcpm_entry_vectors)
.space 4 * MAX_NR_CLUSTERS * MAX_CPUS_PER_CLUSTER
+ .type mcpm_entry_early_pokes, #object
+ENTRY(mcpm_entry_early_pokes)
+ .space 8 * MAX_NR_CLUSTERS * MAX_CPUS_PER_CLUSTER
+
.type mcpm_power_up_setup_phys, #object
ENTRY(mcpm_power_up_setup_phys)
.space 4 @ set by mcpm_sync_init()
diff --git a/arch/arm/include/asm/mcpm.h b/arch/arm/include/asm/mcpm.h
index 0f7b7620e9a5..7626a7fd4938 100644
--- a/arch/arm/include/asm/mcpm.h
+++ b/arch/arm/include/asm/mcpm.h
@@ -42,6 +42,14 @@ extern void mcpm_entry_point(void);
void mcpm_set_entry_vector(unsigned cpu, unsigned cluster, void *ptr);
/*
+ * This sets an early poke i.e a value to be poked into some address
+ * from very early assembly code before the CPU is ungated. The
+ * address must be physical, and if 0 then nothing will happen.
+ */
+void mcpm_set_early_poke(unsigned cpu, unsigned cluster,
+ unsigned long poke_phys_addr, unsigned long poke_val);
+
+/*
* CPU/cluster power operations API for higher subsystems to use.
*/