linux-kernel - [PATCH] arm: skip nomap memblocks while finding the lowmem/highmem boundary

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Date:   Thu, 22 Aug 2019 03:45:34 +0000
From:   Chester Lin <clin@...e.com>
To:     "linux@...linux.org.uk" <linux@...linux.org.uk>,
        "rppt@...ux.ibm.com" <rppt@...ux.ibm.com>,
        "ard.biesheuvel@...aro.org" <ard.biesheuvel@...aro.org>,
        "akpm@...ux-foundation.org" <akpm@...ux-foundation.org>,
        "geert@...ux-m68k.org" <geert@...ux-m68k.org>,
        "tglx@...utronix.de" <tglx@...utronix.de>,
        "mark.rutland@....com" <mark.rutland@....com>
CC:     "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "guillaume.gardet@....com" <guillaume.gardet@....com>,
        Chester Lin <clin@...e.com>, Gary Lin <GLin@...e.com>,
        Joey Lee <JLee@...e.com>
Subject: [PATCH] arm: skip nomap memblocks while finding the lowmem/highmem
 boundary

adjust_lowmem_bounds() checks every memblocks in order to find the boundary
between lowmem and highmem. However some memblocks could be marked as NOMAP
so they are not used by kernel, which should be skipped while calculating
the boundary.

Signed-off-by: Chester Lin <clin@...e.com>
---
 arch/arm/mm/mmu.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 426d9085396b..b86dba44d828 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -1181,6 +1181,9 @@ void __init adjust_lowmem_bounds(void)
 		phys_addr_t block_start = reg->base;
 		phys_addr_t block_end = reg->base + reg->size;
 
+		if (memblock_is_nomap(reg))
+			continue;
+
 		if (reg->base < vmalloc_limit) {
 			if (block_end > lowmem_limit)
 				/*
-- 
2.22.0