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Posted to commits@nuttx.apache.org by xi...@apache.org on 2021/04/13 04:20:29 UTC
[incubator-nuttx] 02/02: arch/arm/src/stm32f7/stm32_allocateheap.c:
Fix MPU alignments
This is an automated email from the ASF dual-hosted git repository.
xiaoxiang pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git
commit 3f6bb76e01b356bc9d7852fe2b900d367e3deea9
Author: Jukka Laitinen <ju...@ssrc.tii.ae>
AuthorDate: Fri Feb 5 16:41:25 2021 +0200
arch/arm/src/stm32f7/stm32_allocateheap.c: Fix MPU alignments
Change the logic for allocating user heap for PROTECTED_BUILD:
- Don't rely on SRAM1_END alignment
- Make better use of MPU subregions when allocating the heap
- Don't duplicate the calculation of user heap start in kernel heap
allocation; use the previous calculation directly
Signed-off-by: Jukka Laitinen <ju...@ssrc.tii.ae>
---
arch/arm/src/stm32/stm32_allocateheap.c | 2 --
arch/arm/src/stm32f7/stm32_allocateheap.c | 45 +++++++++++++------------------
2 files changed, 19 insertions(+), 28 deletions(-)
diff --git a/arch/arm/src/stm32/stm32_allocateheap.c b/arch/arm/src/stm32/stm32_allocateheap.c
index 9d56750..eeb0f0f 100644
--- a/arch/arm/src/stm32/stm32_allocateheap.c
+++ b/arch/arm/src/stm32/stm32_allocateheap.c
@@ -677,7 +677,6 @@ void up_allocate_heap(FAR void **heap_start, size_t *heap_size)
*/
log2 = (int)mpu_log2regionfloor(usize);
- DEBUGASSERT((SRAM1_END & ((1 << log2) - 1)) == 0);
usize = (1 << log2);
ubase = SRAM1_END - usize;
@@ -740,7 +739,6 @@ void up_allocate_kheap(FAR void **heap_start, size_t *heap_size)
*/
log2 = (int)mpu_log2regionfloor(usize);
- DEBUGASSERT((SRAM1_END & ((1 << log2) - 1)) == 0);
usize = (1 << log2);
ubase = SRAM1_END - usize;
diff --git a/arch/arm/src/stm32f7/stm32_allocateheap.c b/arch/arm/src/stm32f7/stm32_allocateheap.c
index 3757eb2..df9705b 100644
--- a/arch/arm/src/stm32f7/stm32_allocateheap.c
+++ b/arch/arm/src/stm32f7/stm32_allocateheap.c
@@ -273,20 +273,29 @@ void up_allocate_heap(FAR void **heap_start, size_t *heap_size)
uintptr_t ubase = (uintptr_t)USERSPACE->us_bssend +
CONFIG_MM_KERNEL_HEAPSIZE;
size_t usize = SRAM1_END - ubase;
+ size_t subreg_mask;
int log2;
- DEBUGASSERT(ubase < (uintptr_t)SRAM1_END);
-
/* Adjust that size to account for MPU alignment requirements.
* NOTE that there is an implicit assumption that the SRAM1_END
* is aligned to the MPU requirement.
*/
- log2 = (int)mpu_log2regionfloor(usize);
- DEBUGASSERT((SRAM1_END & ((1 << log2) - 1)) == 0);
+ /* align the ubase initially to a suitable mpu subregion start */
+
+ log2 = (int)mpu_log2regionceil(usize);
+ subreg_mask = (1 << log2) / 8 - 1;
+ if (ubase & subreg_mask)
+ {
+ ubase = (ubase | subreg_mask) + 1;
+ }
+
+ DEBUGASSERT(ubase < (uintptr_t)SRAM1_END);
+
+ /* reset the size to fit in SRAM and align down to subregion size */
- usize = (1 << log2);
- ubase = SRAM1_END - usize;
+ usize = SRAM1_END - ubase;
+ usize &= ~subreg_mask;
/* Return the user-space heap settings */
@@ -328,35 +337,19 @@ void up_allocate_heap(FAR void **heap_start, size_t *heap_size)
#if defined(CONFIG_BUILD_PROTECTED) && defined(CONFIG_MM_KERNEL_HEAP)
void up_allocate_kheap(FAR void **heap_start, size_t *heap_size)
{
- /* Get the unaligned size and position of the user-space heap.
- * This heap begins after the user-space .bss section at an offset
- * of CONFIG_MM_KERNEL_HEAPSIZE (subject to alignment).
+ /* User heap was just initialized, with proper MPU alignment, in nx_start,
+ * store the user heap start address
*/
- uintptr_t ubase = (uintptr_t)USERSPACE->us_bssend +
- CONFIG_MM_KERNEL_HEAPSIZE;
- size_t usize = SRAM1_END - ubase;
- int log2;
-
+ uintptr_t ubase = (uintptr_t)*heap_start;
DEBUGASSERT(ubase < (uintptr_t)SRAM1_END);
- /* Adjust that size to account for MPU alignment requirements.
- * NOTE that there is an implicit assumption that the SRAM1_END
- * is aligned to the MPU requirement.
- */
-
- log2 = (int)mpu_log2regionfloor(usize);
- DEBUGASSERT((SRAM1_END & ((1 << log2) - 1)) == 0);
-
- usize = (1 << log2);
- ubase = SRAM1_END - usize;
-
/* Return the kernel heap settings (i.e., the part of the heap region
* that was not dedicated to the user heap).
*/
*heap_start = (FAR void *)USERSPACE->us_bssend;
- *heap_size = ubase - (uintptr_t)USERSPACE->us_bssend;
+ *heap_size = ubase - USERSPACE->us_bssend;
}
#endif