This prevents ETM stalls whenever core enters OFF mode. Original patch
author is Richard Woodruff .
This version of the patch makes use of the ETM OS save/restore mechanism,
which takes about 55 words in omap3_arm_context[] instead of 128. Also,
saving ETM context can be switched on/off at runtime.
Signed-off-by: Alexander Shishkin
Cc: Richard Woodruff
Cc: Tony Lindgren
Cc: Russell King
Cc: Paul Walmsley
Cc: Kevin Hilman
Cc: linux-omap@vger.kernel.org
Cc: linux-arm-ker...@lists.infradead.org
Cc: linux-ker...@vger.kernel.org
---
arch/arm/mach-omap2/Kconfig |9 ++
arch/arm/mach-omap2/control.c |2 +-
arch/arm/mach-omap2/sleep34xx.S | 135 +
arch/arm/plat-omap/include/plat/control.h |2 +-
4 files changed, 146 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig
index b48bacf..0413d88 100644
--- a/arch/arm/mach-omap2/Kconfig
+++ b/arch/arm/mach-omap2/Kconfig
@@ -243,6 +243,15 @@ config MACH_OMAP4_PANDA
default y
depends on ARCH_OMAP4
+config ENABLE_OFF_MODE_JTAG_ETM_DEBUG
+ bool "Enable hardware emulation context save and restore"
+ depends on ARCH_OMAP3
+ default y
+ help
+ This option enables JTAG & ETM debugging across power states.
+ With out this option emulation features are reset across OFF
+ mode state changes.
+
config OMAP3_EMU
bool "OMAP3 debugging peripherals"
depends on ARCH_OMAP3
diff --git a/arch/arm/mach-omap2/control.c b/arch/arm/mach-omap2/control.c
index a8d20ee..22dd240 100644
--- a/arch/arm/mach-omap2/control.c
+++ b/arch/arm/mach-omap2/control.c
@@ -93,7 +93,7 @@ void *omap3_secure_ram_storage;
* The address is stored in scratchpad, so that it can be used
* during the restore path.
*/
-u32 omap3_arm_context[128];
+u32 omap3_arm_context[256];
struct omap3_control_regs {
u32 sysconfig;
diff --git a/arch/arm/mach-omap2/sleep34xx.S b/arch/arm/mach-omap2/sleep34xx.S
index d522cd7..cd6a1d4 100644
--- a/arch/arm/mach-omap2/sleep34xx.S
+++ b/arch/arm/mach-omap2/sleep34xx.S
@@ -28,6 +28,7 @@
#include
#include
#include
+#include
#include "cm.h"
#include "prm.h"
@@ -226,6 +227,18 @@ loop:
nop
bl wait_sdrc_ok
+#ifdef CONFIG_ENABLE_OFF_MODE_JTAG_ETM_DEBUG
+ /*
+* Restore Coresight debug registers
+*/
+ ldr r6, debug_vbase /* base Vaddr of CortexA8-Debug */
+ ldr r4, debug_xlar_key /* get lock key for OSLAR */
+ bl unlock_debug/* remove global lock if set */
+ ldr r6, etm_vbase /* base Vaddr of ETM */
+ bl unlock_debug/* remove global lock if set */
+ str r6, [r6, #ETMMR_OSLAR] /* clear OSLAR lock using non-key */
+#endif
+
ldmfd sp!, {r0-r12, pc} @ restore regs and return
restore_es3:
/*b restore_es3*/ @ Enable to debug restore code
@@ -385,6 +398,44 @@ logic_l1_restore:
/*normal memory remap register */
MCR p15, 0, r5, c10, c2, 1
+#ifdef CONFIG_ENABLE_OFF_MODE_JTAG_ETM_DEBUG
+ /*
+* Restore Coresight debug registers
+*/
+ ldr r6, debug_pbase /* base paddr of CortexA8-Debug */
+ ldr r4, debug_xlar_key /* get lock key for OSLAR */
+ bl unlock_debug/* remove global lock if set */
+ str r4, [r6, #ETMMR_OSLAR] /* reset-pointer (already locked) */
+ ldr r4, [r6, #ETMMR_OSSRR] /* dummy read */
+ ldr r4, [r3], #4/* load save size */
+ cmp r4, #0 /* check for zero */
+debug_restore:
+ itttne /* t2/compat if-then block */
+ ldrne r5, [r3], #4/* get saved value */
+ strne r5, [r6,#ETMMR_OSSRR] /* restore saved value */
+ subnes r4, r4, #1 /* decrement loop */
+ bne debug_restore /* loop till done */
+ str r5, [r6, #ETMMR_OSSRR] /* clear lock */
+ /*
+* Restore CoreSight ETM registers
+*/
+ ldr r6, etm_pbase /* base paddr of ETM */
+ ldr r4, debug_xlar_key /* get lock key for OSLAR */
+ bl unlock_debug/* remove global lock if set */
+ str r4, [r6, #ETMMR_OSLAR] /* reset-pointer (already locked) */
+ ldr r4, [r6, #ETMMR_OSSRR] /* dummy read */
+ ldr r4, [r3], #4/* load save size */
+ cmp r4, #0 /* check for zero */
+ beq etm_skip
+etm_restore:
+ ldrne r5, [r3], #4/* get saved value */
+ strne r5, [r6, #ETMMR_OSSRR] /* restore saved value */
+ subnes r4, r4, #1 /* decrement loop */
+ bne etm_restore /* loop till done */
+etm_skip:
+ str r6, [r6, #ETMMR_OSLAR] /* remo
