diff options
Diffstat (limited to 'arch/arm64/mm/init.c')
| -rw-r--r-- | arch/arm64/mm/init.c | 63 |
1 files changed, 61 insertions, 2 deletions
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 52d1fc465885..c0ea54bd9995 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -35,8 +35,10 @@ #include <linux/efi.h> #include <linux/swiotlb.h> +#include <asm/boot.h> #include <asm/fixmap.h> #include <asm/kasan.h> +#include <asm/kernel-pgtable.h> #include <asm/memory.h> #include <asm/sections.h> #include <asm/setup.h> @@ -46,7 +48,13 @@ #include "mm.h" -phys_addr_t memstart_addr __read_mostly = 0; +/* + * We need to be able to catch inadvertent references to memstart_addr + * that occur (potentially in generic code) before arm64_memblock_init() + * executes, which assigns it its actual value. So use a default value + * that cannot be mistaken for a real physical address. + */ +phys_addr_t memstart_addr __read_mostly = ~0ULL; phys_addr_t arm64_dma_phys_limit __read_mostly; #ifdef CONFIG_BLK_DEV_INITRD @@ -160,7 +168,33 @@ early_param("mem", early_mem); void __init arm64_memblock_init(void) { - memblock_enforce_memory_limit(memory_limit); + const s64 linear_region_size = -(s64)PAGE_OFFSET; + + /* + * Select a suitable value for the base of physical memory. + */ + memstart_addr = round_down(memblock_start_of_DRAM(), + ARM64_MEMSTART_ALIGN); + + /* + * Remove the memory that we will not be able to cover with the + * linear mapping. Take care not to clip the kernel which may be + * high in memory. + */ + memblock_remove(max(memstart_addr + linear_region_size, __pa(_end)), + ULLONG_MAX); + if (memblock_end_of_DRAM() > linear_region_size) + memblock_remove(0, memblock_end_of_DRAM() - linear_region_size); + + /* + * Apply the memory limit if it was set. Since the kernel may be loaded + * high up in memory, add back the kernel region that must be accessible + * via the linear mapping. + */ + if (memory_limit != (phys_addr_t)ULLONG_MAX) { + memblock_enforce_memory_limit(memory_limit); + memblock_add(__pa(_text), (u64)(_end - _text)); + } /* * Register the kernel text, kernel data, initrd, and initial @@ -386,3 +420,28 @@ static int __init keepinitrd_setup(char *__unused) __setup("keepinitrd", keepinitrd_setup); #endif + +/* + * Dump out memory limit information on panic. + */ +static int dump_mem_limit(struct notifier_block *self, unsigned long v, void *p) +{ + if (memory_limit != (phys_addr_t)ULLONG_MAX) { + pr_emerg("Memory Limit: %llu MB\n", memory_limit >> 20); + } else { + pr_emerg("Memory Limit: none\n"); + } + return 0; +} + +static struct notifier_block mem_limit_notifier = { + .notifier_call = dump_mem_limit, +}; + +static int __init register_mem_limit_dumper(void) +{ + atomic_notifier_chain_register(&panic_notifier_list, + &mem_limit_notifier); + return 0; +} +__initcall(register_mem_limit_dumper); |