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MIPS: mm: Add check for highmem before removing memory block

PATCH Applied Kyle Hendry 2 participants 2 messages Jun 21 – Jun 29 MIPS

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Kyle Hendry

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#0 lore raw

PATCH 1/1 MIPS: mm: Add check for highmem before removing memory block

If a device has less physical memory than the highmem threshold bootmem_init() doesn't set highstart_pfn. This results in highmem_init() wrongly disabling the entire memory range if the cpu doesn't support highmem. Add a check that highstart_pfn is non zero before removing the highmem block.

Signed-off-by Kyle Hendry <[email protected]>
---
 arch/mips/mm/init.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
arch/mips/mm/init.c +3 -2
index 1c07ca84ee21..352718e43f69 100644
@@ -426,10 +426,11 @@ static inline void __init highmem_init(void)
 	unsigned long tmp;
 
 	/*
-	 * If CPU cannot support HIGHMEM discard the memory above highstart_pfn
+	 * If CPU cannot support HIGHMEM discard any memory above highstart_pfn
 	 */
 	if (cpu_has_dc_aliases) {
-		memblock_remove(PFN_PHYS(highstart_pfn), -1);
+		if (highstart_pfn)
+			memblock_remove(PFN_PHYS(highstart_pfn), -1);
 		return;
 	}
Signature · 1 line
2.43.0
maintainer Applied
#1 lore raw
Quoted 31 lines · Kyle Hendry

If a device has less physical memory than the highmem threshold bootmem_init() doesn't set highstart_pfn. This results in highmem_init() wrongly disabling the entire memory range if the cpu doesn't support highmem. Add a check that highstart_pfn is non zero before removing the highmem block.

Signed-off-by Kyle Hendry <[email protected]>
---
 arch/mips/mm/init.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
arch/mips/mm/init.c +3 -2
index 1c07ca84ee21..352718e43f69 100644
@@ -426,10 +426,11 @@ static inline void __init highmem_init(void)
 	unsigned long tmp;
 
 	/*
-	 * If CPU cannot support HIGHMEM discard the memory above highstart_pfn
+	 * If CPU cannot support HIGHMEM discard any memory above highstart_pfn
 	 */
 	if (cpu_has_dc_aliases) {
-		memblock_remove(PFN_PHYS(highstart_pfn), -1);
+		if (highstart_pfn)
+			memblock_remove(PFN_PHYS(highstart_pfn), -1);
 		return;
 	}
Signature · 1 line
2.43.0

Applied to mips-fixes with

Fixes f171b55f1441 ("mips: fix HIGHMEM initialization")

added.

Thomas.

Signature · 2 lines
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