[rtems commit] arm: Add _AArch32_PMSA_Map_sections_to_regions()
Sebastian Huber
sebh at rtems.org
Fri Mar 11 08:15:19 UTC 2022
Module: rtems
Branch: master
Commit: ca74566f7e28c1835393b3e1bc86a305a8976cc7
Changeset: http://git.rtems.org/rtems/commit/?id=ca74566f7e28c1835393b3e1bc86a305a8976cc7
Author: Sebastian Huber <sebastian.huber at embedded-brains.de>
Date: Mon Jan 17 13:32:39 2022 +0100
arm: Add _AArch32_PMSA_Map_sections_to_regions()
This simplifies unit testing.
---
cpukit/score/cpu/arm/aarch32-psma-init.c | 56 ++++++++++++++--------
.../cpu/arm/include/rtems/score/aarch32-pmsa.h | 54 +++++++++++++++++++++
2 files changed, 90 insertions(+), 20 deletions(-)
diff --git a/cpukit/score/cpu/arm/aarch32-psma-init.c b/cpukit/score/cpu/arm/aarch32-psma-init.c
index f5792e9..350252a 100644
--- a/cpukit/score/cpu/arm/aarch32-psma-init.c
+++ b/cpukit/score/cpu/arm/aarch32-psma-init.c
@@ -48,12 +48,6 @@
#define AARCH32_PSMA_REGION_MAX \
( ( AARCH32_MPUIR_REGION_MASK >> AARCH32_MPUIR_REGION_SHIFT ) + 1 )
-typedef struct {
- uint32_t base;
- uint32_t limit;
- uint32_t attributes;
-} AArch32_PMSA_Region;
-
static void _AArch32_PMSA_Configure(
const AArch32_PMSA_Region *regions,
size_t region_used,
@@ -96,24 +90,17 @@ static void _AArch32_PMSA_Configure(
_ARM_Instruction_synchronization_barrier();
}
-void _AArch32_PMSA_Initialize(
- uint32_t memory_attributes_0,
- uint32_t memory_attributes_1,
+size_t _AArch32_PMSA_Map_sections_to_regions(
const AArch32_PMSA_Section *sections,
- size_t section_count
+ size_t section_count,
+ AArch32_PMSA_Region *regions,
+ size_t region_max
)
{
- AArch32_PMSA_Region regions[ AARCH32_PSMA_REGION_MAX ];
size_t ri;
size_t si;
size_t region_used;
- size_t region_max;
- _AArch32_Write_mair0( memory_attributes_0 );
- _AArch32_Write_mair1( memory_attributes_1 );
-
- region_max = ( _AArch32_Read_mpuir() & AARCH32_MPUIR_REGION_MASK ) >>
- AARCH32_MPUIR_REGION_SHIFT;
region_used = 0;
for ( si = 0; si < section_count; ++si ) {
@@ -159,7 +146,7 @@ void _AArch32_PMSA_Initialize(
size_t i;
if ( region_used >= region_max ) {
- return;
+ return 0;
}
for ( i = ri; i < region_used; ++i ) {
@@ -177,7 +164,7 @@ void _AArch32_PMSA_Initialize(
if ( ri == region_used ) {
if ( region_used >= region_max ) {
- return;
+ return 0;
}
/* New last region */
@@ -188,7 +175,36 @@ void _AArch32_PMSA_Initialize(
}
}
- _AArch32_PMSA_Configure( regions, region_used, region_max );
+ return region_used;
+}
+
+void _AArch32_PMSA_Initialize(
+ uint32_t memory_attributes_0,
+ uint32_t memory_attributes_1,
+ const AArch32_PMSA_Section *sections,
+ size_t section_count
+)
+{
+ AArch32_PMSA_Region regions[ AARCH32_PSMA_REGION_MAX ];
+ size_t region_max;
+ size_t region_used;
+
+ _AArch32_Write_mair0( memory_attributes_0 );
+ _AArch32_Write_mair1( memory_attributes_1 );
+
+ region_max = ( _AArch32_Read_mpuir() & AARCH32_MPUIR_REGION_MASK ) >>
+ AARCH32_MPUIR_REGION_SHIFT;
+
+ region_used = _AArch32_PMSA_Map_sections_to_regions(
+ sections,
+ section_count,
+ regions,
+ region_max
+ );
+
+ if ( region_used > 0 ) {
+ _AArch32_PMSA_Configure( regions, region_used, region_max );
+ }
}
#endif
diff --git a/cpukit/score/cpu/arm/include/rtems/score/aarch32-pmsa.h b/cpukit/score/cpu/arm/include/rtems/score/aarch32-pmsa.h
index 47b0348..d724413 100644
--- a/cpukit/score/cpu/arm/include/rtems/score/aarch32-pmsa.h
+++ b/cpukit/score/cpu/arm/include/rtems/score/aarch32-pmsa.h
@@ -278,6 +278,33 @@ typedef struct {
} AArch32_PMSA_Section;
/**
+ * @brief The region definition is used to configure the Memory Protection
+ * Unit (MPU).
+ *
+ * A region cannot be empty.
+ */
+typedef struct {
+ /**
+ * @brief This member defines the base address of the region.
+ *
+ * The limit address is this the address of the first byte of the region.
+ */
+ uint32_t base;
+
+ /**
+ * @brief This member defines the limit address of the region.
+ *
+ * The limit address is this the address of the last byte of the region.
+ */
+ uint32_t limit;
+
+ /**
+ * @brief This member defines the attributes of the region.
+ */
+ uint32_t attributes;
+} AArch32_PMSA_Region;
+
+/**
* @brief Initializes the Memory Protection Unit (MPU).
*
* The section definitions are used to define the regions of the MPU. Sections
@@ -285,6 +312,8 @@ typedef struct {
* regions are used, then the MPU is not enabled. Overlapping section
* definitions result in undefined system behaviour.
*
+ * The function shall be called while the MPU is disabled.
+ *
* @param memory_attributes_0 are the memory attributes for MAIR0.
*
* @param memory_attributes_1 are the memory attributes for MAIR1.
@@ -301,6 +330,31 @@ void _AArch32_PMSA_Initialize(
);
/**
+ * @brief Maps the section definitions to region definitions.
+ *
+ * The section definitions are used to define the regions of the MPU. Sections
+ * are merged if possible to reduce the count of used regions. If too many
+ * regions are used, then zero is returned. Overlapping section definitions
+ * result in undefined system behaviour.
+ *
+ * @param sections is the array with section definitions to map to regions.
+ *
+ * @param section_count is the count of section definitions.
+ *
+ * @param regions is the array with usable region definitions.
+ *
+ * @param region_max is the count of usable region definitions.
+ *
+ * @return Returns the count of actually used regions.
+ */
+size_t _AArch32_PMSA_Map_sections_to_regions(
+ const AArch32_PMSA_Section *sections,
+ size_t section_count,
+ AArch32_PMSA_Region *regions,
+ size_t region_max
+);
+
+/**
* @brief This array provides section definitions to initialize the memory
* protection unit (MPU).
*
More information about the vc
mailing list