[PATCH v4, part3 01/15] mm: fix build warnings caused by free_reserved_area()

[PATCH v4, part3 01/15] mm: fix build warnings caused by free_reserved_area()

[Jiang Liu]

Fix following build warnings cuased by free_reserved_area():

arch/arm/mm/init.c: In function 'mem_init':
arch/arm/mm/init.c:603:2: warning: passing argument 1 of 'free_reserved_area' makes integer from pointer without a cast [enabled by default]
  free_reserved_area(__va(PHYS_PFN_OFFSET), swapper_pg_dir, 0, NULL);
  ^
In file included from include/linux/mman.h:4:0,
                 from arch/arm/mm/init.c:15:
include/linux/mm.h:1301:22: note: expected 'long unsigned int' but argument is of type 'void *'
 extern unsigned long free_reserved_area(unsigned long start, unsigned long end,

   mm/page_alloc.c: In function 'free_reserved_area':
>> mm/page_alloc.c:5134:3: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast [enabled by default]
   In file included from arch/mips/include/asm/page.h:49:0,
                    from include/linux/mmzone.h:20,
                    from include/linux/gfp.h:4,
                    from include/linux/mm.h:8,
                    from mm/page_alloc.c:18:
   arch/mips/include/asm/io.h:119:29: note: expected 'const volatile void *' but argument is of type 'long unsigned int'
   mm/page_alloc.c: In function 'free_area_init_nodes':
   mm/page_alloc.c:5030:34: warning: array subscript is below array bounds [-Warray-bounds]

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-kernel at vger.kernel.org
Cc: linux-mm at kvack.org
---
 arch/arm/mm/init.c |    6 ++++--
 mm/page_alloc.c    |    2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 9a5cdc0..7a82fcd 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -600,7 +600,8 @@ void __init mem_init(void)
 
 #ifdef CONFIG_SA1111
 	/* now that our DMA memory is actually so designated, we can free it */
-	free_reserved_area(__va(PHYS_PFN_OFFSET), swapper_pg_dir, 0, NULL);
+	free_reserved_area((unsigned long)__va(PHYS_PFN_OFFSET),
+			   (unsigned long)swapper_pg_dir, 0, NULL);
 #endif
 
 	free_highpages();
@@ -728,7 +729,8 @@ void free_initmem(void)
 	extern char __tcm_start, __tcm_end;
 
 	poison_init_mem(&__tcm_start, &__tcm_end - &__tcm_start);
-	free_reserved_area(&__tcm_start, &__tcm_end, 0, "TCM link");
+	free_reserved_area((unsigned long)&__tcm_start,
+			   (unsigned long)&__tcm_end, 0, "TCM link");
 #endif
 
 	poison_init_mem(__init_begin, __init_end - __init_begin);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e4923e9..8bf7956 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5196,7 +5196,7 @@ unsigned long free_reserved_area(unsigned long start, unsigned long end,
 	for (pages = 0; pos < end; pos += PAGE_SIZE, pages++) {
 		if (poison)
 			memset((void *)pos, poison, PAGE_SIZE);
-		free_reserved_page(virt_to_page(pos));
+		free_reserved_page(virt_to_page((void *)pos));
 	}
 
 	if (pages && s)
-- 
1.7.9.5

[PATCH v4, part3 03/15] mm/ARM64: kill poison_init_mem()

[Jiang Liu]

Use free_reserved_area() to poison initmem memory pages and kill
poison_init_mem() on ARM64.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-kernel at vger.kernel.org
---
 arch/arm64/mm/init.c |   17 +++--------------
 1 file changed, 3 insertions(+), 14 deletions(-)

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index e58dd7f..b87bdb8 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -197,14 +197,6 @@ void __init bootmem_init(void)
 	max_pfn = max_low_pfn = max;
 }
 
-/*
- * Poison init memory with an undefined instruction (0x0).
- */
-static inline void poison_init_mem(void *s, size_t count)
-{
-	memset(s, 0, count);
-}
-
 #ifndef CONFIG_SPARSEMEM_VMEMMAP
 static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
 {
@@ -386,8 +378,7 @@ void __init mem_init(void)
 
 void free_initmem(void)
 {
-	poison_init_mem(__init_begin, __init_end - __init_begin);
-	free_initmem_default(-1);
+	free_initmem_default(0);
 }
 
 #ifdef CONFIG_BLK_DEV_INITRD
@@ -396,10 +387,8 @@ static int keep_initrd;
 
 void free_initrd_mem(unsigned long start, unsigned long end)
 {
-	if (!keep_initrd) {
-		poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
-		free_reserved_area(start, end, -1, "initrd");
-	}
+	if (!keep_initrd)
+		free_reserved_area(start, end, 0, "initrd");
 }
 
 static int __init keepinitrd_setup(char *__unused)
-- 
1.7.9.5

[PATCH v4, part3 01/15] mm: fix build warnings caused by free_reserved_area()

[Russell King - ARM Linux]

On Sat, Apr 06, 2013 at 09:54:55PM +0800, Jiang Liu wrote:
> Fix following build warnings cuased by free_reserved_area():
> 
> arch/arm/mm/init.c: In function 'mem_init':
> arch/arm/mm/init.c:603:2: warning: passing argument 1 of 'free_reserved_area' makes integer from pointer without a cast [enabled by default]
>   free_reserved_area(__va(PHYS_PFN_OFFSET), swapper_pg_dir, 0, NULL);
>   ^
> In file included from include/linux/mman.h:4:0,
>                  from arch/arm/mm/init.c:15:
> include/linux/mm.h:1301:22: note: expected 'long unsigned int' but argument is of type 'void *'
>  extern unsigned long free_reserved_area(unsigned long start, unsigned long end,
> 
>    mm/page_alloc.c: In function 'free_reserved_area':
> >> mm/page_alloc.c:5134:3: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast [enabled by default]
>    In file included from arch/mips/include/asm/page.h:49:0,
>                     from include/linux/mmzone.h:20,
>                     from include/linux/gfp.h:4,
>                     from include/linux/mm.h:8,
>                     from mm/page_alloc.c:18:
>    arch/mips/include/asm/io.h:119:29: note: expected 'const volatile void *' but argument is of type 'long unsigned int'
>    mm/page_alloc.c: In function 'free_area_init_nodes':
>    mm/page_alloc.c:5030:34: warning: array subscript is below array bounds [-Warray-bounds]
> 
> Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
> Reported-by: Arnd Bergmann <arnd@arndb.de>
> Cc: linux-arm-kernel at lists.infradead.org
> Cc: linux-kernel at vger.kernel.org
> Cc: linux-mm at kvack.org
> ---
>  arch/arm/mm/init.c |    6 ++++--
>  mm/page_alloc.c    |    2 +-
>  2 files changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
> index 9a5cdc0..7a82fcd 100644
> --- a/arch/arm/mm/init.c
> +++ b/arch/arm/mm/init.c
> @@ -600,7 +600,8 @@ void __init mem_init(void)
>  
>  #ifdef CONFIG_SA1111
>  	/* now that our DMA memory is actually so designated, we can free it */
> -	free_reserved_area(__va(PHYS_PFN_OFFSET), swapper_pg_dir, 0, NULL);
> +	free_reserved_area((unsigned long)__va(PHYS_PFN_OFFSET),
> +			   (unsigned long)swapper_pg_dir, 0, NULL);
>  #endif
>  
>  	free_highpages();
> @@ -728,7 +729,8 @@ void free_initmem(void)
>  	extern char __tcm_start, __tcm_end;
>  
>  	poison_init_mem(&__tcm_start, &__tcm_end - &__tcm_start);
> -	free_reserved_area(&__tcm_start, &__tcm_end, 0, "TCM link");
> +	free_reserved_area((unsigned long)&__tcm_start,
> +			   (unsigned long)&__tcm_end, 0, "TCM link");
>  #endif
>  
>  	poison_init_mem(__init_begin, __init_end - __init_begin);
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index e4923e9..8bf7956 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -5196,7 +5196,7 @@ unsigned long free_reserved_area(unsigned long start, unsigned long end,
>  	for (pages = 0; pos < end; pos += PAGE_SIZE, pages++) {
>  		if (poison)
>  			memset((void *)pos, poison, PAGE_SIZE);
> -		free_reserved_page(virt_to_page(pos));
> +		free_reserved_page(virt_to_page((void *)pos));

Don't all these casts suggest to you that you may have the type wrong
in the first place?

[PATCH v4, part3 01/15] mm: fix build warnings caused by free_reserved_area()

[Jiang Liu]

On 04/20/2013 12:52 AM, Russell King - ARM Linux wrote:
> On Sat, Apr 06, 2013 at 09:54:55PM +0800, Jiang Liu wrote:
>> Fix following build warnings cuased by free_reserved_area():
>>
>> arch/arm/mm/init.c: In function 'mem_init':
>> arch/arm/mm/init.c:603:2: warning: passing argument 1 of 'free_reserved_area' makes integer from pointer without a cast [enabled by default]
>>   free_reserved_area(__va(PHYS_PFN_OFFSET), swapper_pg_dir, 0, NULL);
>>   ^
>> In file included from include/linux/mman.h:4:0,
>>                  from arch/arm/mm/init.c:15:
>> include/linux/mm.h:1301:22: note: expected 'long unsigned int' but argument is of type 'void *'
>>  extern unsigned long free_reserved_area(unsigned long start, unsigned long end,
>>
>>    mm/page_alloc.c: In function 'free_reserved_area':
>>>> mm/page_alloc.c:5134:3: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast [enabled by default]
>>    In file included from arch/mips/include/asm/page.h:49:0,
>>                     from include/linux/mmzone.h:20,
>>                     from include/linux/gfp.h:4,
>>                     from include/linux/mm.h:8,
>>                     from mm/page_alloc.c:18:
>>    arch/mips/include/asm/io.h:119:29: note: expected 'const volatile void *' but argument is of type 'long unsigned int'
>>    mm/page_alloc.c: In function 'free_area_init_nodes':
>>    mm/page_alloc.c:5030:34: warning: array subscript is below array bounds [-Warray-bounds]
>>
>> Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
>> Reported-by: Arnd Bergmann <arnd@arndb.de>
>> Cc: linux-arm-kernel at lists.infradead.org
>> Cc: linux-kernel at vger.kernel.org
>> Cc: linux-mm at kvack.org
>> ---
>>  arch/arm/mm/init.c |    6 ++++--
>>  mm/page_alloc.c    |    2 +-
>>  2 files changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
>> index 9a5cdc0..7a82fcd 100644
>> --- a/arch/arm/mm/init.c
>> +++ b/arch/arm/mm/init.c
>> @@ -600,7 +600,8 @@ void __init mem_init(void)
>>  
>>  #ifdef CONFIG_SA1111
>>  	/* now that our DMA memory is actually so designated, we can free it */
>> -	free_reserved_area(__va(PHYS_PFN_OFFSET), swapper_pg_dir, 0, NULL);
>> +	free_reserved_area((unsigned long)__va(PHYS_PFN_OFFSET),
>> +			   (unsigned long)swapper_pg_dir, 0, NULL);
>>  #endif
>>  
>>  	free_highpages();
>> @@ -728,7 +729,8 @@ void free_initmem(void)
>>  	extern char __tcm_start, __tcm_end;
>>  
>>  	poison_init_mem(&__tcm_start, &__tcm_end - &__tcm_start);
>> -	free_reserved_area(&__tcm_start, &__tcm_end, 0, "TCM link");
>> +	free_reserved_area((unsigned long)&__tcm_start,
>> +			   (unsigned long)&__tcm_end, 0, "TCM link");
>>  #endif
>>  
>>  	poison_init_mem(__init_begin, __init_end - __init_begin);
>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>> index e4923e9..8bf7956 100644
>> --- a/mm/page_alloc.c
>> +++ b/mm/page_alloc.c
>> @@ -5196,7 +5196,7 @@ unsigned long free_reserved_area(unsigned long start, unsigned long end,
>>  	for (pages = 0; pos < end; pos += PAGE_SIZE, pages++) {
>>  		if (poison)
>>  			memset((void *)pos, poison, PAGE_SIZE);
>> -		free_reserved_page(virt_to_page(pos));
>> +		free_reserved_page(virt_to_page((void *)pos));
> 
> Don't all these casts suggest to you that you may have the type wrong
> in the first place?
> 
Hi Russell,
	Good question! 
	Originally free_reserved_area() is designed to simplify free_initrd_mem(), and 
free_initrd_mem() is declared as:
	void free_initrd_mem(unsigned long start, unsigned long end)
	So I have chosen "unsigned long" for free_reserved_area()'s first and second
parameters, otherwise it will cause much more type casts in function free_initrd_mem().
For code purity, we should use "void *" instead. So should we change to "void *" here?
	Regards!
	Gerry