From bd848d1b9235d027e65fcc87de26cc1b02b41cc8 Mon Sep 17 00:00:00 2001 From: Thomas Bogendoerfer Date: Tue, 24 Sep 2019 17:20:51 +0200 Subject: [PATCH] MIPS: init: Prevent adding memory before PHYS_OFFSET On some SGI machines (IP28 and IP30) a small region of memory is mirrored to pyhsical address 0 for exception vectors while rest of the memory is reachable at a higher physical address. ARC PROM marks this region as reserved, but with commit a94e4f24ec83 ("MIPS: init: Drop boot_mem_map") this chunk is used, when searching for start of ram, which breaks at least IP28 and IP30 machines. To fix this add_region_memory() checks for start address < PHYS_OFFSET and ignores these chunks. Fixes: a94e4f24ec83 ("MIPS: init: Drop boot_mem_map") Signed-off-by: Thomas Bogendoerfer Signed-off-by: Paul Burton Cc: Ralf Baechle Cc: James Hogan Cc: linux-mips@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- arch/mips/kernel/setup.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index f5c6b4c6de24..5eec13b8d222 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -108,6 +108,9 @@ void __init add_memory_region(phys_addr_t start, phys_addr_t size, long type) return; } + if (start < PHYS_OFFSET) + return; + memblock_add(start, size); /* Reserve any memory except the ordinary RAM ranges. */ switch (type) { -- 2.20.1