From 9048e648bc22d7b59093f8ca1978c5767893aaa5 Mon Sep 17 00:00:00 2001 From: Alexander Graf Date: Tue, 1 Apr 2014 15:46:05 +0200 Subject: [PATCH] powerpc: Use 64k io pages when we never see an HEA When we never get around to seeing an HEA ethernet adapter, there's no point in restricting ourselves to 4k IO page size. This speeds up IO maps when CONFIG_IBMEBUS is disabled. [ Updated the test to also lift the restriction on arch 2.07 (Power 8) which cannot have an HEA -- BenH ] Signed-off-by: Alexander Graf Signed-off-by: Benjamin Herrenschmidt foo --- arch/powerpc/mm/hash_utils_64.c | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index d766d6ee33fe..12f1a397f502 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -445,6 +445,24 @@ static void mmu_psize_set_default_penc(void) mmu_psize_defs[bpsize].penc[apsize] = -1; } +#ifdef CONFIG_PPC_64K_PAGES + +static bool might_have_hea(void) +{ + /* + * The HEA ethernet adapter requires awareness of the + * GX bus. Without that awareness we can easily assume + * we will never see an HEA ethernet device. + */ +#ifdef CONFIG_IBMEBUS + return !cpu_has_feature(CPU_FTR_ARCH_207S); +#else + return false; +#endif +} + +#endif /* #ifdef CONFIG_PPC_64K_PAGES */ + static void __init htab_init_page_sizes(void) { int rc; @@ -499,10 +517,11 @@ static void __init htab_init_page_sizes(void) mmu_linear_psize = MMU_PAGE_64K; if (mmu_has_feature(MMU_FTR_CI_LARGE_PAGE)) { /* - * Don't use 64k pages for ioremap on pSeries, since - * that would stop us accessing the HEA ethernet. + * When running on pSeries using 64k pages for ioremap + * would stop us accessing the HEA ethernet. So if we + * have the chance of ever seeing one, stay at 4k. */ - if (!machine_is(pseries)) + if (!might_have_hea() || !machine_is(pseries)) mmu_io_psize = MMU_PAGE_64K; } else mmu_ci_restrictions = 1; -- 2.39.2