[rtems commit] bsps/arm: Workaround for Errata 845369
Sebastian Huber
sebh at rtems.org
Fri Oct 16 04:48:22 UTC 2020
Module: rtems
Branch: 5
Commit: 3d7da43562d83faf93f9a3827408d2a13a3658d3
Changeset: http://git.rtems.org/rtems/commit/?id=3d7da43562d83faf93f9a3827408d2a13a3658d3
Author: Sebastian Huber <sebastian.huber at embedded-brains.de>
Date: Fri Oct 2 11:36:20 2020 +0200
bsps/arm: Workaround for Errata 845369
Add a workaround for Cortex-A9 Errata 845369: Under Very Rare Timing
Circumstances Transition into Streaming Mode Might Create Data Corruption.
Update #4114.
---
bsps/arm/include/bsp/arm-a9mpcore-start.h | 15 ++++++++++++
cpukit/score/cpu/arm/include/libcpu/arm-cp15.h | 32 ++++++++++++++++++++++++++
2 files changed, 47 insertions(+)
diff --git a/bsps/arm/include/bsp/arm-a9mpcore-start.h b/bsps/arm/include/bsp/arm-a9mpcore-start.h
index 8423e64..83c84f1 100644
--- a/bsps/arm/include/bsp/arm-a9mpcore-start.h
+++ b/bsps/arm/include/bsp/arm-a9mpcore-start.h
@@ -123,6 +123,20 @@ arm_a9mpcore_start_enable_smp_in_auxiliary_control(void)
actlr |= ARM_CORTEX_A9_ACTL_SMP | ARM_CORTEX_A9_ACTL_FW;
arm_cp15_set_auxiliary_control(actlr);
}
+
+BSP_START_TEXT_SECTION static inline void
+arm_a9mpcore_start_errata_845369_handler(void)
+{
+ uint32_t diag;
+
+ /*
+ * Workaround for Errata 845369: Under Very Rare Timing Circumstances
+ * Transition into Streaming Mode Might Create Data Corruption.
+ */
+ diag = arm_cp15_get_diagnostic_control();
+ diag |= 1U << 22;
+ arm_cp15_set_diagnostic_control(diag);
+}
#endif
BSP_START_TEXT_SECTION static inline void arm_a9mpcore_start_hook_0(void)
@@ -138,6 +152,7 @@ BSP_START_TEXT_SECTION static inline void arm_a9mpcore_start_hook_0(void)
}
#ifdef RTEMS_SMP
+ arm_a9mpcore_start_errata_845369_handler();
arm_a9mpcore_start_enable_smp_in_auxiliary_control();
#endif
diff --git a/cpukit/score/cpu/arm/include/libcpu/arm-cp15.h b/cpukit/score/cpu/arm/include/libcpu/arm-cp15.h
index 8d43ca0..ffe32e4 100644
--- a/cpukit/score/cpu/arm/include/libcpu/arm-cp15.h
+++ b/cpukit/score/cpu/arm/include/libcpu/arm-cp15.h
@@ -2292,6 +2292,38 @@ arm_cp15_set_counter_virtual_offset(uint64_t val)
);
}
+/* Diagnostic Control Register */
+ARM_CP15_TEXT_SECTION static inline uint32_t
+arm_cp15_get_diagnostic_control(void)
+{
+ ARM_SWITCH_REGISTERS;
+ uint32_t val;
+
+ __asm__ volatile (
+ ARM_SWITCH_TO_ARM
+ "mrc p15, 0, %[val], c15, c0, 1\n"
+ ARM_SWITCH_BACK
+ : [val] "=&r" (val) ARM_SWITCH_ADDITIONAL_OUTPUT
+ );
+
+ return val;
+}
+
+/* Diagnostic Control Register */
+ARM_CP15_TEXT_SECTION static inline void
+arm_cp15_set_diagnostic_control(uint32_t val)
+{
+ ARM_SWITCH_REGISTERS;
+
+ __asm__ volatile (
+ ARM_SWITCH_TO_ARM
+ "mcr p15, 0, %[val], c15, c0, 1\n"
+ ARM_SWITCH_BACK
+ : ARM_SWITCH_OUTPUT
+ : [val] "r" (val)
+ );
+}
+
/**
* @brief Sets the @a section_flags for the address range [@a begin, @a end).
*
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