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

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")
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>

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

-- 
Sincerely yours,
Mike.

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