From: Christophe Leroy Date: Mon, 25 Mar 2019 08:43:33 +0000 (+0000) Subject: powerpc/32: Fix early boot failure with RTAS built-in X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=fd427103e8dfcb4b438269afd710b63e7af61463;p=openwrt%2Fstaging%2Fblogic.git powerpc/32: Fix early boot failure with RTAS built-in Commit 0df977eafc79 ("powerpc/6xx: Don't use SPRN_SPRG2 for storing stack pointer while in RTAS") changes the code to use a field in thread struct to store the stack pointer while in RTAS instead of using SPRN_SPRG2. It therefore converts all places which were manipulating SPRN_SPRG2 to use that field. During early startup, the zeroing of SPRN_SPRG2 has been replaced by a zeroing of that field in thread struct. But at least in start_here, that's done wrongly because it used the physical address of the fields while MMU is on at that time. So the virtual address of the field should be used instead, but in the meantime, thread struct has already been zeroed and initialised so we can just drop this initialisation. Reported-by: Larry Finger Fixes: 0df977eafc79 ("powerpc/6xx: Don't use SPRN_SPRG2 for storing stack pointer while in RTAS") Signed-off-by: Christophe Leroy Tested-by: Larry Finger Signed-off-by: Michael Ellerman --- diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S index 48051c8977c5..e25b615e9f9e 100644 --- a/arch/powerpc/kernel/head_32.S +++ b/arch/powerpc/kernel/head_32.S @@ -851,10 +851,6 @@ __secondary_start: tophys(r4,r2) addi r4,r4,THREAD /* phys address of our thread_struct */ mtspr SPRN_SPRG_THREAD,r4 -#ifdef CONFIG_PPC_RTAS - li r3,0 - stw r3, RTAS_SP(r4) /* 0 => not in RTAS */ -#endif lis r4, (swapper_pg_dir - PAGE_OFFSET)@h ori r4, r4, (swapper_pg_dir - PAGE_OFFSET)@l mtspr SPRN_SPRG_PGDIR, r4 @@ -941,10 +937,6 @@ start_here: tophys(r4,r2) addi r4,r4,THREAD /* init task's THREAD */ mtspr SPRN_SPRG_THREAD,r4 -#ifdef CONFIG_PPC_RTAS - li r3,0 - stw r3, RTAS_SP(r4) /* 0 => not in RTAS */ -#endif lis r4, (swapper_pg_dir - PAGE_OFFSET)@h ori r4, r4, (swapper_pg_dir - PAGE_OFFSET)@l mtspr SPRN_SPRG_PGDIR, r4