From 47fee31dbdbd642d444c67a4df814339f6d8dd61 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Fri, 22 Dec 2017 21:17:10 +1000 Subject: [PATCH] powerpc/64: rtas avoid accessing paca in 32-bit mode Commit 177ba7c647f3 ("powerpc/mm/radix: Limit paca allocation in radix") limited the paca allocation address to 1G on pSeries because RTAS return accesses the paca in 32-bit mode: On return from RTAS we access the paca variables and we have 64 bit disabled. This requires us to limit paca in 32 bit range. Fix this by setting ppc64_rma_size to first_memblock_size/1G range. Avoid this limit by switching to 64-bit mode before accessing any memory. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/entry_64.S | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 36878b6ee8b8..371c05fe250a 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -1083,6 +1083,17 @@ __enter_rtas: rtas_return_loc: FIXUP_ENDIAN + /* + * Clear RI and set SF before anything. + */ + mfmsr r6 + li r0,MSR_RI + andc r6,r6,r0 + sldi r0,r0,(MSR_SF_LG - MSR_RI_LG) + or r6,r6,r0 + sync + mtmsrd r6 + /* relocation is off at this point */ GET_PACA(r4) clrldi r4,r4,2 /* convert to realmode address */ @@ -1091,12 +1102,6 @@ rtas_return_loc: 0: mflr r3 ld r3,(1f-0b)(r3) /* get &rtas_restore_regs */ - mfmsr r6 - li r0,MSR_RI - andc r6,r6,r0 - sync - mtmsrd r6 - ld r1,PACAR1(r4) /* Restore our SP */ ld r4,PACASAVEDMSR(r4) /* Restore our MSR */ -- 2.20.1