linux-kernel - [PATCH] arm64: mm: free the initrd reserved memblock in a aligned manner

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Date:   Thu, 4 Jul 2019 07:59:00 +0800
From:   Yi Wang <wang.yi59@....com.cn>
To:     catalin.marinas@....com
Cc:     will.deacon@....com, akpm@...ux-foundation.org,
        rppt@...ux.vnet.ibm.com, f.fainelli@...il.com, logang@...tatee.com,
        robin.murphy@....com, ghackmann@...roid.com, hannes@...xchg.org,
        david@...hat.com, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, xue.zhihong@....com.cn,
        wang.yi59@....com.cn, jiang.xuexin@....com.cn,
        Junhua Huang <huang.junhua@....com.cn>
Subject: [PATCH] arm64: mm: free the initrd reserved memblock in a aligned manner

From: Junhua Huang <huang.junhua@....com.cn>

We should free the reserved memblock in an aligned manner 
because the initrd reserves the memblock in an aligned manner 
in arm64_memblock_init(). 
Otherwise there are some fragments in memblock_reserved regions. e.g.:
/sys/kernel/debug/memblock # cat reserved 
   0: 0x0000000080080000..0x00000000817fafff
   1: 0x0000000083400000..0x0000000083ffffff
   2: 0x0000000090000000..0x000000009000407f
   3: 0x00000000b0000000..0x00000000b000003f
   4: 0x00000000b26184ea..0x00000000b2618fff
The fragments like the ranges from b0000000 to b000003f and 
from b26184ea to b2618fff should be freed.

And we can do free_reserved_area() after memblock_free(),
as free_reserved_area() calls __free_pages(), once we've done 
that it could be allocated somewhere else, 
but memblock and iomem still say this is reserved memory.

Signed-off-by: Junhua Huang <huang.junhua@....com.cn>
---
 arch/arm64/mm/init.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index d2adffb81b5d..03774b8bd364 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -580,8 +580,13 @@ void free_initmem(void)
 #ifdef CONFIG_BLK_DEV_INITRD
 void __init free_initrd_mem(unsigned long start, unsigned long end)
 {
+	unsigned long aligned_start, aligned_end;
+
+	aligned_start = __virt_to_phys(start) & PAGE_MASK;
+	aligned_end = PAGE_ALIGN(__virt_to_phys(end));
+	memblock_free(aligned_end, aligned_end - aligned_start);
 	free_reserved_area((void *)start, (void *)end, 0, "initrd");
-	memblock_free(__virt_to_phys(start), end - start);
+
 }
 #endif

-- 
2.15.2