From: Catalin Marinas catalin.marinas@arm.com
commit d78050ee35440d7879ed94011c52994b8932e96e upstream.
With the introduction of a dynamic ZONE_DMA range based on DT or IORT information, there's no need for CMA allocations from the wider ZONE_DMA32 since on most platforms ZONE_DMA will cover the 32-bit addressable range. Remove the arm64_dma32_phys_limit and set arm64_dma_phys_limit to cover the smallest DMA range required on the platform. CMA allocation and crashkernel reservation now go in the dynamically sized ZONE_DMA, allowing correct functionality on RPi4.
Signed-off-by: Catalin Marinas catalin.marinas@arm.com Cc: Chen Zhou chenzhou10@huawei.com Reviewed-by: Nicolas Saenz Julienne nsaenzjulienne@suse.de Tested-by: Nicolas Saenz Julienne nsaenzjulienne@suse.de # On RPi4B Cc: Kefeng Wang wangkefeng.wang@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/include/asm/processor.h | 3 +-- arch/arm64/mm/init.c | 33 ++++++++++++++++++--------------- 2 files changed, 19 insertions(+), 17 deletions(-)
--- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -96,8 +96,7 @@ #endif /* CONFIG_ARM64_FORCE_52BIT */
extern phys_addr_t arm64_dma_phys_limit; -extern phys_addr_t arm64_dma32_phys_limit; -#define ARCH_LOW_ADDRESS_LIMIT ((arm64_dma_phys_limit ? : arm64_dma32_phys_limit) - 1) +#define ARCH_LOW_ADDRESS_LIMIT (arm64_dma_phys_limit - 1)
struct debug_info { #ifdef CONFIG_HAVE_HW_BREAKPOINT --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -53,13 +53,13 @@ s64 memstart_addr __ro_after_init = -1; EXPORT_SYMBOL(memstart_addr);
/* - * We create both ZONE_DMA and ZONE_DMA32. ZONE_DMA covers the first 1G of - * memory as some devices, namely the Raspberry Pi 4, have peripherals with - * this limited view of the memory. ZONE_DMA32 will cover the rest of the 32 - * bit addressable memory area. + * If the corresponding config options are enabled, we create both ZONE_DMA + * and ZONE_DMA32. By default ZONE_DMA covers the 32-bit addressable memory + * unless restricted on specific platforms (e.g. 30-bit on Raspberry Pi 4). + * In such case, ZONE_DMA32 covers the rest of the 32-bit addressable memory, + * otherwise it is empty. */ phys_addr_t arm64_dma_phys_limit __ro_after_init; -phys_addr_t arm64_dma32_phys_limit __ro_after_init;
#ifdef CONFIG_KEXEC_CORE /* @@ -84,7 +84,7 @@ static void __init reserve_crashkernel(v
if (crash_base == 0) { /* Current arm64 boot protocol requires 2MB alignment */ - crash_base = memblock_find_in_range(0, arm64_dma32_phys_limit, + crash_base = memblock_find_in_range(0, arm64_dma_phys_limit, crash_size, SZ_2M); if (crash_base == 0) { pr_warn("cannot allocate crashkernel (size:0x%llx)\n", @@ -189,6 +189,7 @@ static void __init zone_sizes_init(unsig unsigned long max_zone_pfns[MAX_NR_ZONES] = {0}; unsigned int __maybe_unused acpi_zone_dma_bits; unsigned int __maybe_unused dt_zone_dma_bits; + phys_addr_t __maybe_unused dma32_phys_limit = max_zone_phys(32);
#ifdef CONFIG_ZONE_DMA acpi_zone_dma_bits = fls64(acpi_iort_dma_get_max_cpu_address()); @@ -198,8 +199,12 @@ static void __init zone_sizes_init(unsig max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit); #endif #ifdef CONFIG_ZONE_DMA32 - max_zone_pfns[ZONE_DMA32] = PFN_DOWN(arm64_dma32_phys_limit); + max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit); + if (!arm64_dma_phys_limit) + arm64_dma_phys_limit = dma32_phys_limit; #endif + if (!arm64_dma_phys_limit) + arm64_dma_phys_limit = PHYS_MASK + 1; max_zone_pfns[ZONE_NORMAL] = max;
free_area_init(max_zone_pfns); @@ -393,16 +398,9 @@ void __init arm64_memblock_init(void)
early_init_fdt_scan_reserved_mem();
- if (IS_ENABLED(CONFIG_ZONE_DMA32)) - arm64_dma32_phys_limit = max_zone_phys(32); - else - arm64_dma32_phys_limit = PHYS_MASK + 1; - reserve_elfcorehdr();
high_memory = __va(memblock_end_of_DRAM() - 1) + 1; - - dma_contiguous_reserve(arm64_dma32_phys_limit); }
void __init bootmem_init(void) @@ -438,6 +436,11 @@ void __init bootmem_init(void) zone_sizes_init(min, max);
/* + * Reserve the CMA area after arm64_dma_phys_limit was initialised. + */ + dma_contiguous_reserve(arm64_dma_phys_limit); + + /* * request_standard_resources() depends on crashkernel's memory being * reserved, so do it here. */ @@ -519,7 +522,7 @@ static void __init free_unused_memmap(vo void __init mem_init(void) { if (swiotlb_force == SWIOTLB_FORCE || - max_pfn > PFN_DOWN(arm64_dma_phys_limit ? : arm64_dma32_phys_limit)) + max_pfn > PFN_DOWN(arm64_dma_phys_limit)) swiotlb_init(1); else swiotlb_force = SWIOTLB_NO_FORCE;