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

[Florian Fainelli <f.fainelli@gmail.com>]

Hi Mike,

On 10/27/18 2:13 AM, Mike Rapoport wrote:
> 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@gmail.com>
>> ---
>>  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.

Yes indeed.

> 
>> +
>> +		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.

Humm, yes, actually we made sure before that we called
memblock_reserve() against a properly page aligned region, unlike the
one below.

> 
> What do you think of my version (below)?

Looks good to me, thanks for making those fixes, I will send that
shortly along with patch #2 if that sounds reasonable to you.

> 
>> +		/*
>> +		 * 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
>>
> 
> From 0e5661c6f1ac2d4b08a55d38c6bc224c187af14f Mon Sep 17 00:00:00 2001
> From: Florian Fainelli <f.fainelli@gmail.com>
> Date: Sat, 27 Oct 2018 12:04:58 +0300
> Subject: [PATCH] arm64: Get rid of __early_init_dt_declare_initrd()
> 
> 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@gmail.com>
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
> ---
>  arch/arm64/include/asm/memory.h |  8 --------
>  arch/arm64/mm/init.c            | 40 +++++++++++++++++++++++++---------------
>  2 files changed, 25 insertions(+), 23 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
> index b9644296..dc3ca21 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 9d9582c..dd665be3 100644
> --- a/arch/arm64/mm/init.c
> +++ b/arch/arm64/mm/init.c
> @@ -61,6 +61,8 @@
>  s64 memstart_addr __ro_after_init = -1;
>  phys_addr_t arm64_dma_phys_limit __ro_after_init;
>  
> +static phys_addr_t phys_initrd_start, phys_initrd_end;
> +
>  #ifdef CONFIG_BLK_DEV_INITRD
>  static int __init early_initrd(char *p)
>  {
> @@ -71,8 +73,8 @@ static int __init early_initrd(char *p)
>  	if (*endp == ',') {
>  		size = memparse(endp + 1, NULL);
>  
> -		initrd_start = start;
> -		initrd_end = start + size;
> +		phys_initrd_start = start;
> +		phys_initrd_end = start + size;
>  	}
>  	return 0;
>  }
> @@ -363,6 +365,7 @@ static void __init fdt_enforce_memory_region(void)
>  void __init arm64_memblock_init(void)
>  {
>  	const s64 linear_region_size = -(s64)PAGE_OFFSET;
> +	u64 __maybe_unused base, size;
>  
>  	/* Handle linux,usable-memory-range property */
>  	fdt_enforce_memory_region();
> @@ -407,14 +410,23 @@ void __init arm64_memblock_init(void)
>  		memblock_add(__pa_symbol(_text), (u64)(_end - _text));
>  	}
>  
> -	if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && initrd_start) {
> +	if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) &&
> +	    (initrd_start || phys_initrd_start)) {
>  		/*
>  		 * Add back the memory we just removed if it results in the
>  		 * 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;
> +		if (phys_initrd_start) {
> +			initrd_start = __phys_to_virt(phys_initrd_start);
> +			initrd_end = __phys_to_virt(phys_initrd_end);
> +		} else if (initrd_start) {
> +			phys_initrd_start = __pa(initrd_start);
> +			phys_initrd_end = __pa(initrd_end);
> +		}
> +
> +		base = phys_initrd_start & PAGE_MASK;
> +		size = PAGE_ALIGN(phys_initrd_end - phys_initrd_start);
>  
>  		/*
>  		 * We can only add back the initrd memory if we don't end up
> @@ -433,6 +445,13 @@ void __init arm64_memblock_init(void)
>  			memblock_remove(base, size); /* clear MEMBLOCK_ flags */
>  			memblock_add(base, size);
>  			memblock_reserve(base, size);
> +
> +			/*
> +			 * 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;
>  		}
>  	}
>  
> @@ -454,19 +473,10 @@ void __init arm64_memblock_init(void)
>  	}
>  
>  	/*
> -	 * Register the kernel text, kernel data, initrd, and initial
> +	 * Register the kernel text, kernel data and initial
>  	 * 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);
> -	}
> -#endif
>  
>  	early_init_fdt_scan_reserved_mem();
>  
> 


-- 
Florian