Re: [PATCH v4 1/2] arm64: Get rid of __early_init_dt_declare_initrd()

[Mike Rapoport]

Hi Florian,

On Fri, Oct 26, 2018 at 03:39:50PM -0700, Florian Fainelli wrote:
> ARM64 is the only architecture that re-defines
> __early_init_dt_declare_initrd() in order for that function to populate
> initrd_start/initrd_end with physical addresses instead of virtual
> addresses. Instead of having an override, just get rid of that
> implementation and perform the virtual to physical conversion of these
> addresses in arm64_memblock_init() where relevant.
> 
> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
> ---
>  arch/arm64/include/asm/memory.h |  8 --------
>  arch/arm64/mm/init.c            | 26 ++++++++++++++++----------
>  2 files changed, 16 insertions(+), 18 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
> index b96442960aea..dc3ca21ba240 100644
> --- a/arch/arm64/include/asm/memory.h
> +++ b/arch/arm64/include/asm/memory.h
> @@ -168,14 +168,6 @@
>  #define IOREMAP_MAX_ORDER	(PMD_SHIFT)
>  #endif
>  
> -#ifdef CONFIG_BLK_DEV_INITRD
> -#define __early_init_dt_declare_initrd(__start, __end)			\
> -	do {								\
> -		initrd_start = (__start);				\
> -		initrd_end = (__end);					\
> -	} while (0)
> -#endif
> -
>  #ifndef __ASSEMBLY__
>  
>  #include <linux/bitops.h>
> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> index 3cf87341859f..98ff0f7a0f7a 100644
> --- a/arch/arm64/mm/init.c
> +++ b/arch/arm64/mm/init.c
> @@ -364,6 +364,9 @@ static void __init fdt_enforce_memory_region(void)
>  void __init arm64_memblock_init(void)
>  {
>  	const s64 linear_region_size = -(s64)PAGE_OFFSET;
> +	unsigned long __maybe_unused phys_initrd_size;
> +	u64 __maybe_unused phys_initrd_start;
> +	u64 __maybe_unused base, size;
>  
>  	/* Handle linux,usable-memory-range property */
>  	fdt_enforce_memory_region();
> @@ -414,8 +417,11 @@ void __init arm64_memblock_init(void)
>  		 * initrd to become inaccessible via the linear mapping.
>  		 * Otherwise, this is a no-op
>  		 */
> -		u64 base = initrd_start & PAGE_MASK;
> -		u64 size = PAGE_ALIGN(initrd_end) - base;
> +		phys_initrd_start = __pa(initrd_start);
> +		phys_initrd_size = __pa(initrd_end) - phys_initrd_start;

If initrd_{start,end} are defined by the command line they already would be
physical addresses.

> +
> +		base = phys_initrd_start & PAGE_MASK;
> +		size = PAGE_ALIGN(phys_initrd_size);
>  
>  		/*
>  		 * We can only add back the initrd memory if we don't end up
> @@ -459,15 +465,15 @@ void __init arm64_memblock_init(void)
>  	 * pagetables with memblock.
>  	 */
>  	memblock_reserve(__pa_symbol(_text), _end - _text);
> -#ifdef CONFIG_BLK_DEV_INITRD
> -	if (initrd_start) {
> -		memblock_reserve(initrd_start, initrd_end - initrd_start);
> -
> -		/* the generic initrd code expects virtual addresses */
> -		initrd_start = __phys_to_virt(initrd_start);
> -		initrd_end = __phys_to_virt(initrd_end);
> +	if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && initrd_start) {
> +		memblock_reserve(phys_initrd_start, phys_initrd_size);

this is not needed, as we do memblock_reserve() for the same area earlier.

What do you think of my version (below)?

> +		/*
> +		 * initrd_below_start_ok can be changed by
> +		 * __early_init_dt_declare_initrd(), set it back to what
> +		 * we want here.
> +		 */
> +		initrd_below_start_ok = 0;
>  	}
> -#endif
>  
>  	early_init_fdt_scan_reserved_mem();
>  
> -- 
> 2.17.1
>