diff mbox series

[06/15] powerpc: fadamp: simplify fadump_reserve_crash_area()

Message ID 20200728051153.1590-7-rppt@kernel.org
State New
Headers show
Series memblock: seasonal cleaning^w cleanup | expand

Commit Message

Mike Rapoport July 28, 2020, 5:11 a.m. UTC
From: Mike Rapoport <rppt@linux.ibm.com>

fadump_reserve_crash_area() reserves memory from a specified base address
till the end of the RAM.

Replace iteration through the memblock.memory with a single call to
memblock_reserve() with appropriate  that will take care of proper memory
reservation.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
 arch/powerpc/kernel/fadump.c | 20 +-------------------
 1 file changed, 1 insertion(+), 19 deletions(-)

Comments

Michael Ellerman July 30, 2020, 12:15 p.m. UTC | #1
Mike Rapoport <rppt@kernel.org> writes:
> From: Mike Rapoport <rppt@linux.ibm.com>
>
> fadump_reserve_crash_area() reserves memory from a specified base address
> till the end of the RAM.
>
> Replace iteration through the memblock.memory with a single call to
> memblock_reserve() with appropriate  that will take care of proper memory
                                     ^
                                     parameters?
> reservation.
>
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
> ---
>  arch/powerpc/kernel/fadump.c | 20 +-------------------
>  1 file changed, 1 insertion(+), 19 deletions(-)

I think this looks OK to me, but I don't have a setup to test it easily.
I've added Hari to Cc who might be able to.

But I'll give you an ack in the hope that it works :)

Acked-by: Michael Ellerman <mpe@ellerman.id.au>


> diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
> index 78ab9a6ee6ac..2446a61e3c25 100644
> --- a/arch/powerpc/kernel/fadump.c
> +++ b/arch/powerpc/kernel/fadump.c
> @@ -1658,25 +1658,7 @@ int __init fadump_reserve_mem(void)
>  /* Preserve everything above the base address */
>  static void __init fadump_reserve_crash_area(u64 base)
>  {
> -	struct memblock_region *reg;
> -	u64 mstart, msize;
> -
> -	for_each_memblock(memory, reg) {
> -		mstart = reg->base;
> -		msize  = reg->size;
> -
> -		if ((mstart + msize) < base)
> -			continue;
> -
> -		if (mstart < base) {
> -			msize -= (base - mstart);
> -			mstart = base;
> -		}
> -
> -		pr_info("Reserving %lluMB of memory at %#016llx for preserving crash data",
> -			(msize >> 20), mstart);
> -		memblock_reserve(mstart, msize);
> -	}
> +	memblock_reserve(base, memblock_end_of_DRAM() - base);
>  }
>  
>  unsigned long __init arch_reserved_kernel_pages(void)
> -- 
> 2.26.2
Mike Rapoport Aug. 1, 2020, 10:18 a.m. UTC | #2
On Thu, Jul 30, 2020 at 10:15:13PM +1000, Michael Ellerman wrote:
> Mike Rapoport <rppt@kernel.org> writes:
> > From: Mike Rapoport <rppt@linux.ibm.com>
> >
> > fadump_reserve_crash_area() reserves memory from a specified base address
> > till the end of the RAM.
> >
> > Replace iteration through the memblock.memory with a single call to
> > memblock_reserve() with appropriate  that will take care of proper memory
>                                      ^
>                                      parameters?
> > reservation.
> >
> > Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
> > ---
> >  arch/powerpc/kernel/fadump.c | 20 +-------------------
> >  1 file changed, 1 insertion(+), 19 deletions(-)
> 
> I think this looks OK to me, but I don't have a setup to test it easily.
> I've added Hari to Cc who might be able to.
> 
> But I'll give you an ack in the hope that it works :)

Actually, I did some digging in the git log and the traversal was added
there on purpose by the commit b71a693d3db3 ("powerpc/fadump: exclude
memory holes while reserving memory in second kernel")
Presuming this is still reqruired I'm going to drop this patch and will
simply replace for_each_memblock() with for_each_mem_range() in v2.
 
> Acked-by: Michael Ellerman <mpe@ellerman.id.au>
> 
> 
> > diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
> > index 78ab9a6ee6ac..2446a61e3c25 100644
> > --- a/arch/powerpc/kernel/fadump.c
> > +++ b/arch/powerpc/kernel/fadump.c
> > @@ -1658,25 +1658,7 @@ int __init fadump_reserve_mem(void)
> >  /* Preserve everything above the base address */
> >  static void __init fadump_reserve_crash_area(u64 base)
> >  {
> > -	struct memblock_region *reg;
> > -	u64 mstart, msize;
> > -
> > -	for_each_memblock(memory, reg) {
> > -		mstart = reg->base;
> > -		msize  = reg->size;
> > -
> > -		if ((mstart + msize) < base)
> > -			continue;
> > -
> > -		if (mstart < base) {
> > -			msize -= (base - mstart);
> > -			mstart = base;
> > -		}
> > -
> > -		pr_info("Reserving %lluMB of memory at %#016llx for preserving crash data",
> > -			(msize >> 20), mstart);
> > -		memblock_reserve(mstart, msize);
> > -	}
> > +	memblock_reserve(base, memblock_end_of_DRAM() - base);
> >  }
> >  
> >  unsigned long __init arch_reserved_kernel_pages(void)
> > -- 
> > 2.26.2
Hari Bathini Aug. 1, 2020, 10:53 a.m. UTC | #3
On 01/08/20 3:48 pm, Mike Rapoport wrote:
> On Thu, Jul 30, 2020 at 10:15:13PM +1000, Michael Ellerman wrote:
>> Mike Rapoport <rppt@kernel.org> writes:
>>> From: Mike Rapoport <rppt@linux.ibm.com>
>>>
>>> fadump_reserve_crash_area() reserves memory from a specified base address
>>> till the end of the RAM.
>>>
>>> Replace iteration through the memblock.memory with a single call to
>>> memblock_reserve() with appropriate  that will take care of proper memory
>>                                       ^
>>                                       parameters?
>>> reservation.
>>>
>>> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
>>> ---
>>>   arch/powerpc/kernel/fadump.c | 20 +-------------------
>>>   1 file changed, 1 insertion(+), 19 deletions(-)
>>
>> I think this looks OK to me, but I don't have a setup to test it easily.
>> I've added Hari to Cc who might be able to.
>>
>> But I'll give you an ack in the hope that it works :)
> 
> Actually, I did some digging in the git log and the traversal was added
> there on purpose by the commit b71a693d3db3 ("powerpc/fadump: exclude
> memory holes while reserving memory in second kernel")

I was about to comment on the same :)
memblock_reserve() was being used until we ran into the issue talked 
about in the above commit...

> Presuming this is still reqruired I'm going to drop this patch and will

Yeah, it is still required..

> simply replace for_each_memblock() with for_each_mem_range() in v2.

Sounds right.

>   
>> Acked-by: Michael Ellerman <mpe@ellerman.id.au>
>>
>>
>>> diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
>>> index 78ab9a6ee6ac..2446a61e3c25 100644
>>> --- a/arch/powerpc/kernel/fadump.c
>>> +++ b/arch/powerpc/kernel/fadump.c
>>> @@ -1658,25 +1658,7 @@ int __init fadump_reserve_mem(void)
>>>   /* Preserve everything above the base address */
>>>   static void __init fadump_reserve_crash_area(u64 base)
>>>   {
>>> -	struct memblock_region *reg;
>>> -	u64 mstart, msize;
>>> -
>>> -	for_each_memblock(memory, reg) {
>>> -		mstart = reg->base;
>>> -		msize  = reg->size;
>>> -
>>> -		if ((mstart + msize) < base)
>>> -			continue;
>>> -
>>> -		if (mstart < base) {
>>> -			msize -= (base - mstart);
>>> -			mstart = base;
>>> -		}
>>> -
>>> -		pr_info("Reserving %lluMB of memory at %#016llx for preserving crash data",
>>> -			(msize >> 20), mstart);
>>> -		memblock_reserve(mstart, msize);
>>> -	}
>>> +	memblock_reserve(base, memblock_end_of_DRAM() - base);
>>>   }
>>>   
>>>   unsigned long __init arch_reserved_kernel_pages(void)
>>> -- 
>>> 2.26.2
> 

Thanks
Hari
Michael Ellerman Aug. 2, 2020, 1:14 p.m. UTC | #4
Mike Rapoport <rppt@kernel.org> writes:
> On Thu, Jul 30, 2020 at 10:15:13PM +1000, Michael Ellerman wrote:
>> Mike Rapoport <rppt@kernel.org> writes:
>> > From: Mike Rapoport <rppt@linux.ibm.com>
>> >
>> > fadump_reserve_crash_area() reserves memory from a specified base address
>> > till the end of the RAM.
>> >
>> > Replace iteration through the memblock.memory with a single call to
>> > memblock_reserve() with appropriate  that will take care of proper memory
>>                                      ^
>>                                      parameters?
>> > reservation.
>> >
>> > Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
>> > ---
>> >  arch/powerpc/kernel/fadump.c | 20 +-------------------
>> >  1 file changed, 1 insertion(+), 19 deletions(-)
>> 
>> I think this looks OK to me, but I don't have a setup to test it easily.
>> I've added Hari to Cc who might be able to.
>> 
>> But I'll give you an ack in the hope that it works :)
>
> Actually, I did some digging in the git log and the traversal was added
> there on purpose by the commit b71a693d3db3 ("powerpc/fadump: exclude
> memory holes while reserving memory in second kernel")
> Presuming this is still reqruired I'm going to drop this patch and will
> simply replace for_each_memblock() with for_each_mem_range() in v2.

Thanks.

cheers
diff mbox series

Patch

diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 78ab9a6ee6ac..2446a61e3c25 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -1658,25 +1658,7 @@  int __init fadump_reserve_mem(void)
 /* Preserve everything above the base address */
 static void __init fadump_reserve_crash_area(u64 base)
 {
-	struct memblock_region *reg;
-	u64 mstart, msize;
-
-	for_each_memblock(memory, reg) {
-		mstart = reg->base;
-		msize  = reg->size;
-
-		if ((mstart + msize) < base)
-			continue;
-
-		if (mstart < base) {
-			msize -= (base - mstart);
-			mstart = base;
-		}
-
-		pr_info("Reserving %lluMB of memory at %#016llx for preserving crash data",
-			(msize >> 20), mstart);
-		memblock_reserve(mstart, msize);
-	}
+	memblock_reserve(base, memblock_end_of_DRAM() - base);
 }
 
 unsigned long __init arch_reserved_kernel_pages(void)