releases/5.10.32/arm-9069-1-nommu-fix-conversion-for_each_membock-to-.patch

From cf3bbccb6b41a56baed531c4edb3159155480783 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Thu, 11 Mar 2021 13:32:16 +0100
Subject: ARM: 9069/1: NOMMU: Fix conversion for_each_membock() to
 for_each_mem_range()

From: Vladimir Murzin <vladimir.murzin@arm.com>

[ Upstream commit 45c2f70cba3a7eff34574103b2e2b901a5f771aa ]

for_each_mem_range() uses a loop variable, yet looking into code it is
not just iteration counter but more complex entity which encodes
information about memblock. Thus condition i == 0 looks fragile.
Indeed, it broke boot of R-class platforms since it never took i == 0
path (due to i was set to 1). Fix that with restoring original flag
check.

Fixes: b10d6bca8720 ("arch, drivers: replace for_each_membock() with for_each_mem_range()")
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm/mm/pmsa-v7.c | 4 +++-
 arch/arm/mm/pmsa-v8.c | 4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mm/pmsa-v7.c b/arch/arm/mm/pmsa-v7.c
index 88950e41a3a9..59d916ccdf25 100644
--- a/arch/arm/mm/pmsa-v7.c
+++ b/arch/arm/mm/pmsa-v7.c
@@ -235,6 +235,7 @@ void __init pmsav7_adjust_lowmem_bounds(void)
 	phys_addr_t mem_end;
 	phys_addr_t reg_start, reg_end;
 	unsigned int mem_max_regions;
+	bool first = true;
 	int num;
 	u64 i;
 
@@ -263,7 +264,7 @@ void __init pmsav7_adjust_lowmem_bounds(void)
 #endif
 
 	for_each_mem_range(i, &reg_start, &reg_end) {
-		if (i == 0) {
+		if (first) {
 			phys_addr_t phys_offset = PHYS_OFFSET;
 
 			/*
@@ -275,6 +276,7 @@ void __init pmsav7_adjust_lowmem_bounds(void)
 			mem_start = reg_start;
 			mem_end = reg_end;
 			specified_mem_size = mem_end - mem_start;
+			first = false;
 		} else {
 			/*
 			 * memblock auto merges contiguous blocks, remove
diff --git a/arch/arm/mm/pmsa-v8.c b/arch/arm/mm/pmsa-v8.c
index 2de019f7503e..8359748a19a1 100644
--- a/arch/arm/mm/pmsa-v8.c
+++ b/arch/arm/mm/pmsa-v8.c
@@ -95,10 +95,11 @@ void __init pmsav8_adjust_lowmem_bounds(void)
 {
 	phys_addr_t mem_end;
 	phys_addr_t reg_start, reg_end;
+	bool first = true;
 	u64 i;
 
 	for_each_mem_range(i, &reg_start, &reg_end) {
-		if (i == 0) {
+		if (first) {
 			phys_addr_t phys_offset = PHYS_OFFSET;
 
 			/*
@@ -107,6 +108,7 @@ void __init pmsav8_adjust_lowmem_bounds(void)
 			if (reg_start != phys_offset)
 				panic("First memory bank must be contiguous from PHYS_OFFSET");
 			mem_end = reg_end;
+			first = false;
 		} else {
 			/*
 			 * memblock auto merges contiguous blocks, remove
-- 
2.30.2