From dbfcf3cb9c681aa0c5d0bb46068f98d5b1823dd3 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Thu, 16 Feb 2017 16:03:39 +1100 Subject: [PATCH] powerpc/64: Call H_REGISTER_PROC_TBL when running as a HPT guest on POWER9 On POWER9, since commit cc3d2940133d ("powerpc/64: Enable use of radix MMU under hypervisor on POWER9", 2017-01-30), we set both the radix and HPT bits in the client-architecture-support (CAS) vector, which tells the hypervisor that we can do either radix or HPT. According to PAPR, if we use this combination we are promising to do a H_REGISTER_PROC_TBL hcall later on to let the hypervisor know whether we are doing radix or HPT. We currently do this call if we are doing radix but not if we are doing HPT. If the hypervisor is able to support both radix and HPT guests, it would be entitled to defer allocation of the HPT until the H_REGISTER_PROC_TBL call, and to fail any attempts to create HPTEs until the H_REGISTER_PROC_TBL call. Thus we need to do a H_REGISTER_PROC_TBL call when we are doing HPT; otherwise we may crash at boot time. This adds the code to call H_REGISTER_PROC_TBL in this case, before we attempt to create any HPT entries using H_ENTER. Fixes: cc3d2940133d ("powerpc/64: Enable use of radix MMU under hypervisor on POWER9") Cc: stable@vger.kernel.org # v4.11+ Signed-off-by: Paul Mackerras Reviewed-by: Suraj Jitindar Singh Signed-off-by: Michael Ellerman --- arch/powerpc/mm/hash_utils_64.c | 6 ++++++ arch/powerpc/platforms/pseries/lpar.c | 8 ++++++-- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index b578148..17fc13c 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -875,6 +875,12 @@ static void __init htab_initialize(void) /* Using a hypervisor which owns the htab */ htab_address = NULL; _SDR1 = 0; + /* + * On POWER9, we need to do a H_REGISTER_PROC_TBL hcall + * to inform the hypervisor that we wish to use the HPT. + */ + if (cpu_has_feature(CPU_FTR_ARCH_300)) + register_process_table(0, 0, 0); #ifdef CONFIG_FA_DUMP /* * If firmware assisted dump is active firmware preserves diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c index 0ee4a46..d11f3c1 100644 --- a/arch/powerpc/platforms/pseries/lpar.c +++ b/arch/powerpc/platforms/pseries/lpar.c @@ -726,15 +726,18 @@ static int pseries_lpar_resize_hpt(unsigned long shift) return 0; } -/* Actually only used for radix, so far */ static int pseries_lpar_register_process_table(unsigned long base, unsigned long page_size, unsigned long table_size) { long rc; - unsigned long flags = PROC_TABLE_NEW; + unsigned long flags = 0; + if (table_size) + flags |= PROC_TABLE_NEW; if (radix_enabled()) flags |= PROC_TABLE_RADIX | PROC_TABLE_GTSE; + else + flags |= PROC_TABLE_HPT_SLB; for (;;) { rc = plpar_hcall_norets(H_REGISTER_PROC_TBL, flags, base, page_size, table_size); @@ -760,6 +763,7 @@ void __init hpte_init_pseries(void) mmu_hash_ops.flush_hash_range = pSeries_lpar_flush_hash_range; mmu_hash_ops.hpte_clear_all = pseries_hpte_clear_all; mmu_hash_ops.hugepage_invalidate = pSeries_lpar_hugepage_invalidate; + register_process_table = pseries_lpar_register_process_table; if (firmware_has_feature(FW_FEATURE_HPT_RESIZE)) mmu_hash_ops.resize_hpt = pseries_lpar_resize_hpt; -- 2.7.4