Commit d2e38dec authored Jun 02, 2017 by Maureen Helm Committed by Kumar Gala Jun 12, 2017

arm: nxp: mpu: Return constant number of mpu regions



The original implementation of _get_num_regions() parsed the CESR[NRGD]
register field to determine the number of mpu region descriptors
implemented in hardware. There was a possible path in the code to return
zero, which would cause underflow later on in arm_core_mpu_configure().
Coverity complained despite an assert to catch this condition. Instead,
use a preprocessor macro from mcux that defines the number of mpu region
descriptors.

Coverity-CID: 169811
Jira: ZEP-2208

Signed-off-by: Maureen Helm <maureen.helm@nxp.com>

parent c0682a9d

arch/arm/core/cortex_m/mpu/nxp_mpu.c

+1 −16

Original line number	Diff line number	Diff line
		@@ -38,22 +38,7 @@ static inline u32_t _get_region_attr_by_type(u32_t type)

		static inline u8_t _get_num_regions(void)
		{
		u32_t type = (SYSMPU->CESR & SYSMPU_CESR_NRGD_MASK)
		>> SYSMPU_CESR_NRGD_SHIFT;

		switch (type) {
		case 0:
		return 8;
		case 1:
		return 12;
		case 2:
		return 16;
		default:
		__ASSERT(0, "Unsupported MPU configuration.");
		return 0;
		}

		return NXP_MPU_REGION_NUMBER;
		return FSL_FEATURE_SYSMPU_DESCRIPTOR_COUNT;
		}

		static void _region_init(u32_t index, u32_t region_base,

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