On 01/08/20 3:48 pm, Mike Rapoport wrote:

On Thu, Jul 30, 2020 at 10:15:13PM +1000, Michael Ellerman wrote:

quoted

Mike Rapoport [off-list ref] writes:

quoted

From: Mike Rapoport <redacted>

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?

quoted

reservation.

Signed-off-by: Mike Rapoport <redacted>
---
  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.

quoted

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

quoted

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

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel