On 1/5/26 13:15, Ahmad Fatoum wrote:
> On 1/5/26 12:26 PM, Sascha Hauer wrote:
>> Add PBL-specific memory remapping function that always uses page-wise
>> mapping (ARCH_MAP_FLAG_PAGEWISE) for fine-grained permissions on
>> adjacent ELF segments with different protection requirements.
>>
>> Wraps arch-specific __arch_remap_range() for ARMv7 (4KB pages) and
>> ARMv8 (page tables with BBM). Needed for ELF segment permission setup.
>>
>> Signed-off-by: Sascha Hauer <[email protected]>
>
> Reviewed-by: Ahmad Fatoum <[email protected]>
Hmm, a question: Why do we need to preemptively break up pages?
Doesn't normal remapping do that already? My understanding was
that we only did it here to allow remapping while executing from
it, but in the PBL ELF loader we are not executing from there,
so there should not be an issue.
Thanks,
Ahmad
>
>> ---
>> arch/arm/cpu/mmu_32.c | 7 +++++++
>> arch/arm/cpu/mmu_64.c | 8 ++++++++
>> include/mmu.h | 3 +++
>> 3 files changed, 18 insertions(+)
>>
>> diff --git a/arch/arm/cpu/mmu_32.c b/arch/arm/cpu/mmu_32.c
>> index
>> 97c7107290ce95ddb21a322a5d0e74f3d324c528..86a55d165ba3cec5154c345a1a3a9cb959f0996f
>> 100644
>> --- a/arch/arm/cpu/mmu_32.c
>> +++ b/arch/arm/cpu/mmu_32.c
>> @@ -435,6 +435,13 @@ static void early_remap_range(u32 addr, size_t size,
>> maptype_t map_type)
>> __arch_remap_range((void *)addr, addr, size, map_type);
>> }
>>
>> +void pbl_remap_range(void *virt_addr, phys_addr_t phys_addr, size_t size,
>> + maptype_t map_type)
>> +{
>> + __arch_remap_range(virt_addr, phys_addr, size,
>> + map_type | ARCH_MAP_FLAG_PAGEWISE);
>> +}
>> +
>> static bool pte_is_cacheable(uint32_t pte, int level)
>> {
>> return (level == 2 && (pte & PTE_CACHEABLE)) ||
>> diff --git a/arch/arm/cpu/mmu_64.c b/arch/arm/cpu/mmu_64.c
>> index
>> afb3d2d7efd0bc7ecde1177d1544f54d751b5dc1..63faaa46703697e527eae766392e7ea7ae186b3d
>> 100644
>> --- a/arch/arm/cpu/mmu_64.c
>> +++ b/arch/arm/cpu/mmu_64.c
>> @@ -282,6 +282,14 @@ static void early_remap_range(uint64_t addr, size_t
>> size, maptype_t map_type)
>> __arch_remap_range(addr, addr, size, map_type, false);
>> }
>>
>> +void pbl_remap_range(void *virt_addr, phys_addr_t phys_addr, size_t size,
>> + maptype_t map_type)
>> +{
>> + __arch_remap_range((uint64_t)virt_addr, phys_addr,
>> + (uint64_t)size, map_type | ARCH_MAP_FLAG_PAGEWISE,
>> + true);
>> +}
>> +
>> int arch_remap_range(void *virt_addr, phys_addr_t phys_addr, size_t size,
>> maptype_t map_type)
>> {
>> map_type = arm_mmu_maybe_skip_permissions(map_type);
>> diff --git a/include/mmu.h b/include/mmu.h
>> index
>> 53603b7956c229b4c715c57b19d0398931eb2d6b..37df7b482e1d83e94e61997db6cf9834d8cf7f3c
>> 100644
>> --- a/include/mmu.h
>> +++ b/include/mmu.h
>> @@ -64,6 +64,9 @@ static inline bool arch_can_remap(void)
>> }
>> #endif
>>
>> +void pbl_remap_range(void *virt_addr, phys_addr_t phys_addr, size_t size,
>> + maptype_t map_type);
>> +
>> static inline int remap_range(void *start, size_t size, maptype_t map_type)
>> {
>> return arch_remap_range(start, virt_to_phys(start), size, map_type);
>>
>
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