[PATCH] riscv: Fix 32-bit RISC-V boot failure

Bin Meng bmeng.cn at gmail.com
Sun Jun 27 06:51:17 PDT 2021

Commit dd2d082b5760 ("riscv: Cleanup setup_bootmem()") adjusted
the calling sequence in setup_bootmem(), which invalidates the fix
commit de043da0b9e7 ("RISC-V: Fix usage of memblock_enforce_memory_limit")
did for 32-bit RISC-V unfortunately.

So now 32-bit RISC-V does not boot again when testing booting kernel
on QEMU 'virt' with '-m 2G', which was exactly what the original
commit de043da0b9e7 ("RISC-V: Fix usage of memblock_enforce_memory_limit")
tried to fix.

Fixes: dd2d082b5760 ("riscv: Cleanup setup_bootmem()")
Cc: stable at vger.kernel.org # v5.12+
Signed-off-by: Bin Meng <bmeng.cn at gmail.com>

 arch/riscv/mm/init.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 4c4c92ce0bb8..9b23b95c50cf 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -123,7 +123,7 @@ void __init setup_bootmem(void)
 	phys_addr_t vmlinux_end = __pa_symbol(&_end);
 	phys_addr_t vmlinux_start = __pa_symbol(&_start);
-	phys_addr_t dram_end = memblock_end_of_DRAM();
+	phys_addr_t dram_end;
 	phys_addr_t max_mapped_addr = __pa(~(ulong)0);
@@ -146,6 +146,8 @@ void __init setup_bootmem(void)
 	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
+	dram_end = memblock_end_of_DRAM();
 	 * memblock allocator is not aware of the fact that last 4K bytes of
 	 * the addressable memory can not be mapped because of IS_ERR_VALUE

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