From c610d65c0ad00f1b7bfe2f1eb8f867ca74741685 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Fri, 22 Dec 2017 21:17:12 +1000 Subject: [PATCH] powerpc/pseries: lift RTAS limit for hash With the previous patch to switch to 64-bit mode after returning from RTAS and before doing any memory accesses, the RMA limit need not be clamped to 1GB to avoid RTAS bugs. Keep the 1GB limit for older firmware (although this is more of a kernel concern than RTAS), and remove it starting with POWER9. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- arch/powerpc/mm/hash_utils_64.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index a386bd854b1c..64e704eefad1 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -1853,11 +1853,13 @@ void hash__setup_initial_memory_limit(phys_addr_t first_memblock_base, * non-virtualized 64-bit hash MMU systems don't have a limitation * on real mode access. * - * We also clamp it to 1G to avoid some funky things - * such as RTAS bugs etc... + * For guests on platforms before POWER9, we clamp the it limit to 1G + * to avoid some funky things such as RTAS bugs etc... */ if (!early_cpu_has_feature(CPU_FTR_HVMODE)) { - ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000); + ppc64_rma_size = first_memblock_size; + if (!early_cpu_has_feature(CPU_FTR_ARCH_300)) + ppc64_rma_size = min_t(u64, ppc64_rma_size, 0x40000000); /* Finally limit subsequent allocations */ memblock_set_current_limit(ppc64_rma_size);