Commit 0d9fad91 authored by Kars de Jong's avatar Kars de Jong Committed by Geert Uytterhoeven
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m68k: mm: Fix systems with memory at end of 32-bit address space 

The calculation of end addresses of memory chunks overflowed to 0 when
a memory chunk is located at the end of 32-bit address space.
This is the case for the HP300 architecture.

Link: https://lore.kernel.org/linux-m68k/CACz-3rhUo5pgNwdWHaPWmz+30Qo9xCg70wNxdf7o5x-6tXq8QQ@mail.gmail.com/


Signed-off-by: default avatarKars de Jong <jongk@linux-m68k.org>
Reviewed-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20230223112349.26675-1-jongk@linux-m68k.org


Signed-off-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
parent fe15c26e

arch/m68k/mm/motorola.c

+5 −5
Original line number Diff line number Diff line
@@ -437,7 +437,7 @@ void __init paging_init(void) 
	}



	min_addr = m68k_memory[0].addr;

	max_addr = min_addr + m68k_memory[0].size;

	max_addr = min_addr + m68k_memory[0].size - 1;

	memblock_add_node(m68k_memory[0].addr, m68k_memory[0].size, 0,

			  MEMBLOCK_NONE);

	for (i = 1; i < m68k_num_memory;) {
@@ -452,21 +452,21 @@ void __init paging_init(void) 
		}

		memblock_add_node(m68k_memory[i].addr, m68k_memory[i].size, i,

				  MEMBLOCK_NONE);

		addr = m68k_memory[i].addr + m68k_memory[i].size;

		addr = m68k_memory[i].addr + m68k_memory[i].size - 1;

		if (addr > max_addr)

			max_addr = addr;

		i++;

	}

	m68k_memoffset = min_addr - PAGE_OFFSET;

	m68k_virt_to_node_shift = fls(max_addr - min_addr - 1) - 6;

	m68k_virt_to_node_shift = fls(max_addr - min_addr) - 6;



	module_fixup(NULL, __start_fixup, __stop_fixup);

	flush_icache();



	high_memory = phys_to_virt(max_addr);

	high_memory = phys_to_virt(max_addr) + 1;



	min_low_pfn = availmem >> PAGE_SHIFT;

	max_pfn = max_low_pfn = max_addr >> PAGE_SHIFT;

	max_pfn = max_low_pfn = (max_addr >> PAGE_SHIFT) + 1;



	/* Reserve kernel text/data/bss and the memory allocated in head.S */

	memblock_reserve(m68k_memory[0].addr, availmem - m68k_memory[0].addr);