This is a note to let you know that I've just added the patch titled powerpc: Fix early setup to make early_ioremap() work to the 5.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: powerpc-fix-early-setup-to-make-early_ioremap-work.patch and it can be found in the queue-5.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 0192416ebc73ce9757b60f221c8cde2dd4944586 Author: Alexey Kardashevskiy <aik@xxxxxxxxx> Date: Thu May 20 13:29:19 2021 +1000 powerpc: Fix early setup to make early_ioremap() work [ Upstream commit e2f5efd0f0e229bd110eab513e7c0331d61a4649 ] The immediate problem is that after commit 0bd3f9e953bd ("powerpc/legacy_serial: Use early_ioremap()") the kernel silently reboots on some systems. The reason is that early_ioremap() returns broken addresses as it uses slot_virt[] array which initialized with offsets from FIXADDR_TOP == IOREMAP_END+FIXADDR_SIZE == KERN_IO_END - FIXADDR_SIZ + FIXADDR_SIZE == __kernel_io_end which is 0 when early_ioremap_setup() is called. __kernel_io_end is initialized little bit later in early_init_mmu(). This fixes the initialization by swapping early_ioremap_setup() and early_init_mmu(). Fixes: 265c3491c4bc ("powerpc: Add support for GENERIC_EARLY_IOREMAP") Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx> Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx> [mpe: Drop unrelated cleanup & cleanup change log] Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210520032919.358935-1-aik@xxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index 830fee91b2d9..c914fe8a2c67 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -369,11 +369,11 @@ void __init early_setup(unsigned long dt_ptr) apply_feature_fixups(); setup_feature_keys(); - early_ioremap_setup(); - /* Initialize the hash table or TLB handling */ early_init_mmu(); + early_ioremap_setup(); + /* * After firmware and early platform setup code has set things up, * we note the SPR values for configurable control/performance