Nicholas Piggin <npig...@gmail.com> writes:
> DD2.3 missed out on getting its feature flag bits.
>
> This meant when booting with dt-cpu-ftrs, CPU_FTR_P9_TM_HV_ASSIST is
> missing (unless the firmware contains it, which mine does not seem to).
> And when booting without, CPU_FTR_P9_TM_XER_SO_BUG is set.
>
> In practice this doesn't make any difference to pseries guests, only
> powernv.
>
> Signed-off-by: Nicholas Piggin <npig...@gmail.com>
> ---
> arch/powerpc/include/asm/cputable.h | 2 ++
> arch/powerpc/kernel/cputable.c | 22 ++++++++++++++++++++--
> arch/powerpc/kernel/dt_cpu_ftrs.c | 14 +++++---------
> 3 files changed, 27 insertions(+), 11 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/cputable.h
> b/arch/powerpc/include/asm/cputable.h
> index e85c849214a2..46bae9624784 100644
> --- a/arch/powerpc/include/asm/cputable.h
> +++ b/arch/powerpc/include/asm/cputable.h
> @@ -440,6 +440,8 @@ static inline void cpu_feature_keys_init(void) { }
> #define CPU_FTRS_POWER9_DD2_2 (CPU_FTRS_POWER9 | CPU_FTR_POWER9_DD2_1 | \
> CPU_FTR_P9_TM_HV_ASSIST | \
> CPU_FTR_P9_TM_XER_SO_BUG)
> +#define CPU_FTRS_POWER9_DD2_3 (CPU_FTRS_POWER9 | CPU_FTR_POWER9_DD2_1 | \
> + CPU_FTR_P9_TM_HV_ASSIST)
> #define CPU_FTRS_POWER10 (CPU_FTR_LWSYNC | \
> CPU_FTR_PPCAS_ARCH_V2 | CPU_FTR_CTRL | CPU_FTR_ARCH_206 |\
> CPU_FTR_MMCRA | CPU_FTR_SMT | \
> diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c
> index ae0fdef0ac11..9ab97d1fd5a2 100644
> --- a/arch/powerpc/kernel/cputable.c
> +++ b/arch/powerpc/kernel/cputable.c
> @@ -487,11 +487,29 @@ static struct cpu_spec __initdata cpu_specs[] = {
> .machine_check_early = __machine_check_early_realmode_p9,
> .platform = "power9",
> },
> - { /* Power9 DD2.2 or later */
> + { /* Power9 DD 2.2 */
> + .pvr_mask = 0xffffefff,
> + .pvr_value = 0x004e0202,
> + .cpu_name = "POWER9 (raw)",
> + .cpu_features = CPU_FTRS_POWER9_DD2_2,
> + .cpu_user_features = COMMON_USER_POWER9,
> + .cpu_user_features2 = COMMON_USER2_POWER9,
> + .mmu_features = MMU_FTRS_POWER9,
> + .icache_bsize = 128,
> + .dcache_bsize = 128,
> + .num_pmcs = 6,
> + .pmc_type = PPC_PMC_IBM,
> + .oprofile_cpu_type = "ppc64/power9",
> + .cpu_setup = __setup_cpu_power9,
> + .cpu_restore = __restore_cpu_power9,
> + .machine_check_early = __machine_check_early_realmode_p9,
> + .platform = "power9",
> + },
> + { /* Power9 DD 2.3 or later */
> .pvr_mask = 0xffff0000,
> .pvr_value = 0x004e0000,
> .cpu_name = "POWER9 (raw)",
> - .cpu_features = CPU_FTRS_POWER9_DD2_2,
> + .cpu_features = CPU_FTRS_POWER9_DD2_3,
> .cpu_user_features = COMMON_USER_POWER9,
> .cpu_user_features2 = COMMON_USER2_POWER9,
> .mmu_features = MMU_FTRS_POWER9,
> diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c
> b/arch/powerpc/kernel/dt_cpu_ftrs.c
> index 358aee7c2d79..af95f337e54b 100644
> --- a/arch/powerpc/kernel/dt_cpu_ftrs.c
> +++ b/arch/powerpc/kernel/dt_cpu_ftrs.c
> @@ -764,18 +764,14 @@ static __init void cpufeatures_cpu_quirks(void)
> * Not all quirks can be derived from the cpufeatures device tree.
> */
> if ((version & 0xffffefff) == 0x004e0200) {
> - /* DD2.0 has no feature flag */
> - cur_cpu_spec->cpu_features |= CPU_FTR_P9_RADIX_PREFETCH_BUG;
> + cur_cpu_spec->cpu_features |= CPU_FTRS_POWER9_DD2_0;
> } else if ((version & 0xffffefff) == 0x004e0201) {
> - cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD2_1;
> - cur_cpu_spec->cpu_features |= CPU_FTR_P9_RADIX_PREFETCH_BUG;
> + cur_cpu_spec->cpu_features |= CPU_FTRS_POWER9_DD2_1;
> } else if ((version & 0xffffefff) == 0x004e0202) {
> - cur_cpu_spec->cpu_features |= CPU_FTR_P9_TM_HV_ASSIST;
> - cur_cpu_spec->cpu_features |= CPU_FTR_P9_TM_XER_SO_BUG;
> - cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD2_1;
> + cur_cpu_spec->cpu_features |= CPU_FTRS_POWER9_DD2_2;
> } else if ((version & 0xffff0000) == 0x004e0000) {
> - /* DD2.1 and up have DD2_1 */
> - cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD2_1;
> + /* DD2.3 and up */
> + cur_cpu_spec->cpu_features |= CPU_FTRS_POWER9_DD2_3;
> }
As we discussed on slack, this part is wrong.
Or'ing in the full CPU_FTRS_POWER9_DDx mask sets bits that may have been
turned off, or never enabled, by the device tree CPU features.
In particular it causes CPU_FTR_TM to be turned on (from
CPU_FTRS_POWER9), even though the machine may not have TM enabled.
We can probably just drop the dt_cpu_ftrs.c change, but if you don't
mind I'll get you to test that and resubmit the series.
cheers
