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arm: mpu: Unify ARM_MPU kconfig definitions

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Previously, there were two separate Kconfig definitions
of ARM_MPU located at:
- arch/arm/core/mpu/Kconfig
- arch/arm64/core/cortex_r/Kconfig

This lead to incomplete default settings and unexpected
missing configurations.

This commit combines the two into a single unified definition
now located at arch/common/Kconfig to prevent this.

Signed-off-by: Samuel Chee <samche01@arm.com>
This commit is contained in:
Samuel Chee 2024-10-15 13:04:09 +01:00 committed by Benjamin Cabé
parent f9e4bc3af2
commit d9eed167d0
3 changed files with 44 additions and 74 deletions
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41
arch/arm/core/mpu/Kconfig
View file

@ -5,47 +5,6 @@
if CPU_HAS_MPU if CPU_HAS_MPU
config ARM_MPU
bool "ARM MPU Support"
select MPU
select SRAM_REGION_PERMISSIONS
select THREAD_STACK_INFO
select ARCH_HAS_EXECUTABLE_PAGE_BIT
select MPU_REQUIRES_POWER_OF_TWO_ALIGNMENT if !(CPU_HAS_NXP_SYSMPU || ARMV8_M_BASELINE || ARMV8_M_MAINLINE || AARCH32_ARMV8_R)
select MPU_REQUIRES_NON_OVERLAPPING_REGIONS if CPU_HAS_ARM_MPU && (ARMV8_M_BASELINE || ARMV8_M_MAINLINE || AARCH32_ARMV8_R)
select MPU_GAP_FILLING if AARCH32_ARMV8_R
select ARCH_MEM_DOMAIN_SUPPORTS_ISOLATED_STACKS
select MEM_DOMAIN_ISOLATED_STACKS
help
MCU implements Memory Protection Unit.
Notes:
The ARMv6-M and ARMv7-M MPU architecture requires a power-of-two
alignment of MPU region base address and size.
The NXP MPU as well as the ARMv8-M MPU do not require MPU regions
to have power-of-two alignment for base address and region size.
The ARMv8-M MPU requires the active MPU regions be non-overlapping.
As a result of this, the ARMv8-M MPU needs to fully partition the
memory map when programming dynamic memory regions (e.g. PRIV stack
guard, user thread stack, and application memory domains), if the
system requires PRIV access policy different from the access policy
of the ARMv8-M background memory map. The application developer may
enforce full PRIV (kernel) memory partition by enabling the
CONFIG_MPU_GAP_FILLING option.
By not enforcing full partition, MPU may leave part of kernel
SRAM area covered only by the default ARMv8-M memory map. This
is fine for User Mode, since the background ARM map does not
allow nPRIV access at all. However, since the background map
policy allows instruction fetches by privileged code, forcing
this Kconfig option off prevents the system from directly
triggering MemManage exceptions upon accidental attempts to
execute code from SRAM in XIP builds.
Since this does not compromise User Mode, we make the skipping
of full partitioning the default behavior for the ARMv8-M MPU
driver.
config ARM_MPU_REGION_MIN_ALIGN_AND_SIZE config ARM_MPU_REGION_MIN_ALIGN_AND_SIZE
int int
default 256 if ARM_MPU && ARMV6_M_ARMV8_M_BASELINE && !ARMV8_M_BASELINE default 256 if ARM_MPU && ARMV6_M_ARMV8_M_BASELINE && !ARMV8_M_BASELINE

33
arch/arm64/core/cortex_r/Kconfig
View file

@ -7,39 +7,6 @@
if CPU_HAS_MPU if CPU_HAS_MPU
config ARM_MPU
bool "ARM MPU Support"
select THREAD_STACK_INFO
select MPU
select SRAM_REGION_PERMISSIONS
select ARCH_MEM_DOMAIN_SYNCHRONOUS_API if USERSPACE
default y
help
MPU implements Memory Protection Unit.
Notes:
The ARMv8-R MPU architecture requires a power-of-two alignment
of MPU region base address and size(64 bytes aligned).
The ARMv8-R MPU requires the active MPU regions be non-overlapping.
As a result of this, the ARMv8-R MPU needs to fully partition the
memory map when programming dynamic memory regions (e.g. PRIV stack
guard, user thread stack, and application memory domains), if the
system requires PRIV access policy different from the access policy
of the ARMv8-R background memory map. The application developer may
enforce full PRIV (kernel) memory partition by enabling the
CONFIG_MPU_GAP_FILLING option.
By not enforcing full partition, MPU may leave part of kernel
SRAM area covered only by the default ARMv8-R memory map. This
is fine for User Mode, since the background ARM map does not
allow nPRIV access at all. However, since the background map
policy allows instruction fetches by privileged code, forcing
this Kconfig option off prevents the system from directly
triggering MemManage exceptions upon accidental attempts to
execute code from SRAM in XIP builds.
Since this does not compromise User Mode, we make the skipping
of full partitioning the default behavior for the ARMv8-R MPU
driver.
config ARM_MPU_REGION_MIN_ALIGN_AND_SIZE config ARM_MPU_REGION_MIN_ALIGN_AND_SIZE
int int

44
arch/common/Kconfig
View file

@ -37,3 +37,47 @@ config ISR_TABLE_SHELL
depends on SHELL depends on SHELL
help help
This option enables a shell command to dump the ISR tables. This option enables a shell command to dump the ISR tables.
config ARM_MPU
bool "ARM MPU Support"
select MPU
select SRAM_REGION_PERMISSIONS
select THREAD_STACK_INFO
select ARCH_HAS_EXECUTABLE_PAGE_BIT if (CPU_AARCH32_CORTEX_R || CPU_CORTEX_M)
select MPU_REQUIRES_POWER_OF_TWO_ALIGNMENT if !(CPU_HAS_NXP_SYSMPU || ARMV8_M_BASELINE || ARMV8_M_MAINLINE || AARCH32_ARMV8_R)
select MPU_REQUIRES_NON_OVERLAPPING_REGIONS if CPU_HAS_ARM_MPU && (ARMV8_M_BASELINE || ARMV8_M_MAINLINE || AARCH32_ARMV8_R)
select MPU_GAP_FILLING if AARCH32_ARMV8_R
select ARCH_MEM_DOMAIN_SUPPORTS_ISOLATED_STACKS if (CPU_AARCH32_CORTEX_R || CPU_CORTEX_M)
select ARCH_MEM_DOMAIN_SYNCHRONOUS_API if USERSPACE && CPU_AARCH64_CORTEX_R
default y if CPU_AARCH64_CORTEX_R
depends on CPU_HAS_MPU
help
MCU implements Memory Protection Unit.
Notes:
The ARMv6-M, ARMv7-M, and ARMv8-R MPU MPU architecture requires a power-of-two
alignment of MPU region base address and size.
The NXP MPU as well as the ARMv8-M MPU do not require MPU regions
to have power-of-two alignment for base address and region size.
The ARMv8-M and ARMv8-R MPU requires the active MPU regions be non-overlapping.
As a result of this, both respective MPUs needs to fully partition the
memory map when programming dynamic memory regions (e.g. PRIV stack
guard, user thread stack, and application memory domains), if the
system requires PRIV access policy different from the access policy
of the ARMv8-M or ARMv8-R background memory map. The application developer may
enforce full PRIV (kernel) memory partition by enabling the
MPU_GAP_FILLING option.
By not enforcing full partition, MPU may leave part of kernel
SRAM area covered only by the default ARMv8-M or ARMv8-R memory map. This
is fine for User Mode, since the background ARM map does not
allow nPRIV access at all. However, since the background map
policy allows instruction fetches by privileged code, forcing
this Kconfig option off prevents the system from directly
triggering MemManage exceptions upon accidental attempts to
execute code from SRAM in XIP builds.
Since this does not compromise User Mode, we make the skipping
of full partitioning the default behavior for the ARMv8-M and ARMv8-R MPU
driver.