(nuttx) branch master updated: arm64: fix mpu_freeregion

[ligd]

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ligd pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/nuttx.git


The following commit(s) were added to refs/heads/master by this push:
     new 14e5d8a9955 arm64: fix mpu_freeregion
14e5d8a9955 is described below

commit 14e5d8a995510a8dc0394b062bf1d662a9802172
Author: hujun5 <huj...@xiaomi.com>
AuthorDate: Tue May 13 15:12:59 2025 +0800

    arm64: fix mpu_freeregion
    
    The limit register contains the enable/disable bit for the MPU region,
    so it must be written first before writing the base register to ensure
    proper region disable operation.
    
    Signed-off-by: hujun5 <huj...@xiaomi.com>
---
 arch/arm64/src/common/arm64_mpu.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/src/common/arm64_mpu.c 
b/arch/arm64/src/common/arm64_mpu.c
index 41f3c081a64..e9cd12e44f9 100644
--- a/arch/arm64/src/common/arm64_mpu.c
+++ b/arch/arm64/src/common/arm64_mpu.c
@@ -187,10 +187,14 @@ void mpu_freeregion(unsigned int region)
   write_sysreg(region, prselr_el1);
   UP_DSB();
 
-  /* Set the region base, limit and attribute */
+  /* Set the region base, limit and attribute
+   * Have to set limit register first as the enable/disable bit of the
+   * region is in the limit register.
+   */
 
-  write_sysreg(0, prbar_el1);
   write_sysreg(0, prlar_el1);
+  write_sysreg(0, prbar_el1);
+
   g_mpu_region[this_cpu()] &= ~(1 << region);
   UP_MB();
 }