Two major changes in this patch: [1] Add memblock_mem_limit_mark_nomap(phys_addr_t limit) function to mark memblock regions above the @limit as NOMAP region, which will be used to address the observed 'mem=x' kernel parameter issue. [2] Add 'size' and 'flag' debug output in the memblock debugfs. The '/sys/kernel/debug/memblock/memory' output looks like before: 0: 0x0000008000000000..0x0000008001e7ffff 1: 0x0000008001e80000..0x00000083ff184fff 2: 0x00000083ff185000..0x00000083ff1c2fff 3: 0x00000083ff1c3000..0x00000083ff222fff 4: 0x00000083ff223000..0x00000083ffe42fff 5: 0x00000083ffe43000..0x00000083ffffffff With this patch applied: 0: 0x0000008000000000..0x0000008001e7ffff 0x0000000001e80000 0x4 1: 0x0000008001e80000..0x00000083ff184fff 0x00000003fd305000 0x0 2: 0x00000083ff185000..0x00000083ff1c2fff 0x000000000003e000 0x4 3: 0x00000083ff1c3000..0x00000083ff222fff 0x0000000000060000 0x0 4: 0x00000083ff223000..0x00000083ffe42fff 0x0000000000c20000 0x4 5: 0x00000083ffe43000..0x00000083ffffffff 0x00000000001bd000 0x0 Signed-off-by: Dennis Chen <dennis.chen@xxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Steve Capper <steve.capper@xxxxxxx> Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx> Cc: linux-mm@xxxxxxxxx Cc: linux-acpi@xxxxxxxxxxxxxxx Cc: linux-efi@xxxxxxxxxxxxxxx --- include/linux/memblock.h | 2 ++ mm/memblock.c | 50 ++++++++++++++++++++++++++++++++++++++++-------- 2 files changed, 44 insertions(+), 8 deletions(-) diff --git a/include/linux/memblock.h b/include/linux/memblock.h index 6c14b61..5e069c8 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -92,6 +92,7 @@ int memblock_mark_hotplug(phys_addr_t base, phys_addr_t size); int memblock_clear_hotplug(phys_addr_t base, phys_addr_t size); int memblock_mark_mirror(phys_addr_t base, phys_addr_t size); int memblock_mark_nomap(phys_addr_t base, phys_addr_t size); +int memblock_clear_nomap(phys_addr_t base, phys_addr_t size); ulong choose_memblock_flags(void); /* Low level functions */ @@ -332,6 +333,7 @@ phys_addr_t memblock_mem_size(unsigned long limit_pfn); phys_addr_t memblock_start_of_DRAM(void); phys_addr_t memblock_end_of_DRAM(void); void memblock_enforce_memory_limit(phys_addr_t memory_limit); +void memblock_mem_limit_mark_nomap(phys_addr_t limit); bool memblock_is_memory(phys_addr_t addr); int memblock_is_map_memory(phys_addr_t addr); int memblock_is_region_memory(phys_addr_t base, phys_addr_t size); diff --git a/mm/memblock.c b/mm/memblock.c index ca09915..60930ac 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -814,6 +814,18 @@ int __init_memblock memblock_mark_nomap(phys_addr_t base, phys_addr_t size) } /** + * memblock_clear_nomap - Clear flag MEMBLOCK_NOMAP for a specified region. + * @base: the base phys addr of the region + * @size: the size of the region + * + * Return 0 on success, -errno on failure. + */ +int __init_memblock memblock_clear_nomap(phys_addr_t base, phys_addr_t size) +{ + return memblock_setclr_flag(base, size, 0, MEMBLOCK_NOMAP); +} + +/** * __next_reserved_mem_region - next function for for_each_reserved_region() * @idx: pointer to u64 loop variable * @out_start: ptr to phys_addr_t for start address of the region, can be %NULL @@ -1465,14 +1477,11 @@ phys_addr_t __init_memblock memblock_end_of_DRAM(void) return (memblock.memory.regions[idx].base + memblock.memory.regions[idx].size); } -void __init memblock_enforce_memory_limit(phys_addr_t limit) +static phys_addr_t __find_max_addr(phys_addr_t limit) { phys_addr_t max_addr = (phys_addr_t)ULLONG_MAX; struct memblock_region *r; - if (!limit) - return; - /* find out max address */ for_each_memblock(memory, r) { if (limit <= r->size) { @@ -1482,6 +1491,18 @@ void __init memblock_enforce_memory_limit(phys_addr_t limit) limit -= r->size; } + return max_addr; +} + +void __init memblock_enforce_memory_limit(phys_addr_t limit) +{ + phys_addr_t max_addr; + + if (!limit) + return; + + max_addr = __find_max_addr(limit); + /* truncate both memory and reserved regions */ memblock_remove_range(&memblock.memory, max_addr, (phys_addr_t)ULLONG_MAX); @@ -1489,6 +1510,17 @@ void __init memblock_enforce_memory_limit(phys_addr_t limit) (phys_addr_t)ULLONG_MAX); } +void __init memblock_mem_limit_mark_nomap(phys_addr_t limit) +{ + phys_addr_t max_addr; + + if (!limit) + return; + + max_addr = __find_max_addr(limit); + memblock_mark_nomap(max_addr, (phys_addr_t)ULLONG_MAX); +} + static int __init_memblock memblock_search(struct memblock_type *type, phys_addr_t addr) { unsigned int left = 0, right = type->cnt; @@ -1677,13 +1709,15 @@ static int memblock_debug_show(struct seq_file *m, void *private) reg = &type->regions[i]; seq_printf(m, "%4d: ", i); if (sizeof(phys_addr_t) == 4) - seq_printf(m, "0x%08lx..0x%08lx\n", + seq_printf(m, "0x%08lx..0x%08lx 0x%08lx 0x%lx\n", (unsigned long)reg->base, - (unsigned long)(reg->base + reg->size - 1)); + (unsigned long)(reg->base + reg->size - 1), + (unsigned long)reg->size, reg->flags); else - seq_printf(m, "0x%016llx..0x%016llx\n", + seq_printf(m, "0x%016llx..0x%016llx 0x%016llx 0x%lx\n", (unsigned long long)reg->base, - (unsigned long long)(reg->base + reg->size - 1)); + (unsigned long long)(reg->base + reg->size - 1), + (unsigned long long)reg->size, reg->flags); } return 0; -- 1.8.3.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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