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arch/arm/src/stm32f7/stm32_allocateheap.c: Fix MPU alignments

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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 <jukkax@ssrc.tii.ae>
This commit is contained in:
Jukka Laitinen 2021-02-05 16:41:25 +02:00 committed by Xiang Xiao
parent ea36c2c7ea
commit 3f6bb76e01
2 changed files with 19 additions and 28 deletions
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2
arch/arm/src/stm32/stm32_allocateheap.c
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@ -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;

45
arch/arm/src/stm32f7/stm32_allocateheap.c
View File

@ -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 */
usize = (1 << log2);
ubase = SRAM1_END - usize;
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 = 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