diff options
Diffstat (limited to 'arch/arm64/mm/init.c')
| -rw-r--r-- | arch/arm64/mm/init.c | 45 |
1 files changed, 35 insertions, 10 deletions
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index db63cc885771..8ac25f19084e 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -61,10 +61,35 @@ EXPORT_SYMBOL(memstart_addr); * 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. + * + * Memory reservation for crash kernel either done early or deferred + * depending on DMA memory zones configs (ZONE_DMA) -- + * + * In absence of ZONE_DMA configs arm64_dma_phys_limit initialized + * here instead of max_zone_phys(). This lets early reservation of + * crash kernel memory which has a dependency on arm64_dma_phys_limit. + * Reserving memory early for crash kernel allows linear creation of block + * mappings (greater than page-granularity) for all the memory bank rangs. + * In this scheme a comparatively quicker boot is observed. + * + * If ZONE_DMA configs are defined, crash kernel memory reservation + * is delayed until DMA zone memory range size initilazation performed in + * zone_sizes_init(). The defer is necessary to steer clear of DMA zone + * memory range to avoid overlap allocation. So crash kernel memory boundaries + * are not known when mapping all bank memory ranges, which otherwise means + * not possible to exclude crash kernel range from creating block mappings + * so page-granularity mappings are created for the entire memory range. + * Hence a slightly slower boot is observed. + * + * Note: Page-granularity mapppings are necessary for crash kernel memory + * range for shrinking its size via /sys/kernel/kexec_crash_size interface. */ -phys_addr_t arm64_dma_phys_limit __ro_after_init; +#if IS_ENABLED(CONFIG_ZONE_DMA) || IS_ENABLED(CONFIG_ZONE_DMA32) +phys_addr_t __ro_after_init arm64_dma_phys_limit; +#else +phys_addr_t __ro_after_init arm64_dma_phys_limit = PHYS_MASK + 1; +#endif -#ifdef CONFIG_KEXEC_CORE /* * reserve_crashkernel() - reserves memory for crash kernel * @@ -78,6 +103,9 @@ static void __init reserve_crashkernel(void) unsigned long long crash_max = arm64_dma_phys_limit; int ret; + if (!IS_ENABLED(CONFIG_KEXEC_CORE)) + return; + ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), &crash_size, &crash_base); /* no crashkernel= or invalid value specified */ @@ -110,11 +138,6 @@ static void __init reserve_crashkernel(void) crashk_res.start = crash_base; crashk_res.end = crash_base + crash_size - 1; } -#else -static void __init reserve_crashkernel(void) -{ -} -#endif /* CONFIG_KEXEC_CORE */ /* * Return the maximum physical address for a zone accessible by the given bits @@ -153,8 +176,6 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max) 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); @@ -315,6 +336,9 @@ void __init arm64_memblock_init(void) early_init_fdt_scan_reserved_mem(); + if (!IS_ENABLED(CONFIG_ZONE_DMA) && !IS_ENABLED(CONFIG_ZONE_DMA32)) + reserve_crashkernel(); + high_memory = __va(memblock_end_of_DRAM() - 1) + 1; } @@ -361,7 +385,8 @@ void __init bootmem_init(void) * request_standard_resources() depends on crashkernel's memory being * reserved, so do it here. */ - reserve_crashkernel(); + if (IS_ENABLED(CONFIG_ZONE_DMA) || IS_ENABLED(CONFIG_ZONE_DMA32)) + reserve_crashkernel(); memblock_dump_all(); } |