From: Nicolas Saenz Julienne nsaenzjulienne@suse.de
commit 095507dc1350b3a2b8b39fdc05edba0c10859eca upstream.
Systems configured with CONFIG_ZONE_DMA32, CONFIG_ZONE_NORMAL and !CONFIG_ZONE_DMA will fail to properly setup ARCH_LOW_ADDRESS_LIMIT. The limit will default to ~0ULL, effectively spanning the whole memory, which is too high for a configuration that expects low memory to be capped at 4GB.
Fix ARCH_LOW_ADDRESS_LIMIT by falling back to arm64_dma32_phys_limit when arm64_dma_phys_limit isn't set. arm64_dma32_phys_limit will honour CONFIG_ZONE_DMA32, or span the entire memory when not enabled.
Fixes: 1a8e1cef7603 ("arm64: use both ZONE_DMA and ZONE_DMA32") Signed-off-by: Nicolas Saenz Julienne nsaenzjulienne@suse.de Link: https://lore.kernel.org/r/20201218163307.10150-1-nsaenzjulienne@suse.de Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/arm64/include/asm/processor.h | 3 ++- arch/arm64/mm/init.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-)
--- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -96,7 +96,8 @@ #endif /* CONFIG_ARM64_FORCE_52BIT */
extern phys_addr_t arm64_dma_phys_limit; -#define ARCH_LOW_ADDRESS_LIMIT (arm64_dma_phys_limit - 1) +extern phys_addr_t arm64_dma32_phys_limit; +#define ARCH_LOW_ADDRESS_LIMIT ((arm64_dma_phys_limit ? : arm64_dma32_phys_limit) - 1)
struct debug_info { #ifdef CONFIG_HAVE_HW_BREAKPOINT --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -60,7 +60,7 @@ EXPORT_SYMBOL(memstart_addr); * bit addressable memory area. */ phys_addr_t arm64_dma_phys_limit __ro_after_init; -static phys_addr_t arm64_dma32_phys_limit __ro_after_init; +phys_addr_t arm64_dma32_phys_limit __ro_after_init;
#ifdef CONFIG_KEXEC_CORE /*