Commit 6083fe74 authored Jan 15, 2015 by Mark Rutland Committed by Catalin Marinas Jan 16, 2015

arm64: respect mem= for EFI



When booting with EFI, we acquire the EFI memory map after parsing the
early params. This unfortuantely renders the option useless as we call
memblock_enforce_memory_limit (which uses memblock_remove_range behind
the scenes) before we've added any memblocks. We end up removing
nothing, then adding all of memory later when efi_init calls
reserve_regions.

Instead, we can log the limit and apply this later when we do the rest
of the memblock work in memblock_init, which should work regardless of
the presence of EFI. At the same time we may as well move the early
parameter into arm64's mm/init.c, close to arm64_memblock_init.

Any memory which must be mapped (e.g. for use by EFI runtime services)
must be mapped explicitly reather than relying on the linear mapping,
which may be truncated as a result of a mem= option passed on the kernel
command line.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

parent 7fe5d2b1

arch/arm64/kernel/setup.c

+0 −19

Original line number	Diff line number	Diff line
		@@ -322,25 +322,6 @@ static void __init setup_machine_fdt(phys_addr_t dt_phys)
		dump_stack_set_arch_desc("%s (DT)", of_flat_dt_get_machine_name());
		}

		/*
		* Limit the memory size that was specified via FDT.
		*/
		static int __init early_mem(char *p)
		{
		phys_addr_t limit;

		if (!p)
		return 1;

		limit = memparse(p, &p) & PAGE_MASK;
		pr_notice("Memory limited to %lldMB\n", limit >> 20);

		memblock_enforce_memory_limit(limit);

		return 0;
		}
		early_param("mem", early_mem);

		static void __init request_standard_resources(void)
		{
		struct memblock_region *region;

arch/arm64/mm/init.c

+19 −0

Original line number	Diff line number	Diff line
		@@ -136,10 +136,29 @@ static void arm64_memory_present(void)
		}
		#endif

		static phys_addr_t memory_limit = (phys_addr_t)ULLONG_MAX;

		/*
		* Limit the memory size that was specified via FDT.
		*/
		static int __init early_mem(char *p)
		{
		if (!p)
		return 1;

		memory_limit = memparse(p, &p) & PAGE_MASK;
		pr_notice("Memory limited to %lldMB\n", memory_limit >> 20);

		return 0;
		}
		early_param("mem", early_mem);

		void __init arm64_memblock_init(void)
		{
		phys_addr_t dma_phys_limit = 0;

		memblock_enforce_memory_limit(memory_limit);

		/*
		* Register the kernel text, kernel data, initrd, and initial
		* pagetables with memblock.

Admin message