Re: [PATCH v2 12/21] mmu: introduce pbl_remap_range()

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Hi,

On 1/6/26 1:53 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 <s.hauer@pengutronix.de>

The verdict was that we shouldn't need PAGEWISE here and in that case,
we could just use normal remap_range function, right?

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 71ead41c3d274548c9427c1ce9833de309114c4d..54371e3e5973c9fe98cadef63499105134e09539 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 ddf1373ec0a801baad043146187d7f4c3eac6a2a..d4d6d1a849ba9b8666f4dcb4bd80247a70bdce1a 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 9f582f25e1de14d47cfe2eff64f9cce81c4e492d..32d9a7aca3b9a61d542bf3e21e27f1ac51f43ee2 100644
> --- a/include/mmu.h
> +++ b/include/mmu.h
> @@ -65,6 +65,9 @@ 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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