Commit d78050ee authored by Catalin Marinas's avatar Catalin Marinas
Browse files

arm64: Remove arm64_dma32_phys_limit and its uses 



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: default avatarCatalin Marinas <catalin.marinas@arm.com>
Cc: Chen Zhou <chenzhou10@huawei.com>
Reviewed-by: default avatarNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> # On RPi4B
parent 7c53f6b6

arch/arm64/include/asm/processor.h

+1 −2
Original line number Diff line number Diff line
@@ -94,8 +94,7 @@ 
#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

arch/arm64/mm/init.c

+18 −15
Original line number Diff line number Diff line
@@ -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(void) 


	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",
@@ -196,6 +196,7 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max) 
	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());
@@ -205,8 +206,12 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max) 
	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);
@@ -394,16 +399,9 @@ 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) 
	sparse_init();

	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.
@@ -455,7 +458,7 @@ void __init bootmem_init(void) 
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;