From: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> [ Upstream commit d7e02f7b7991dbe14a2acfb0e53d675cd149001c ] Avoids confusion when printing Oops message like below Faulting instruction address: 0xc00000000008bdb4 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix MMU=Hash SMP NR_CPUS=2048 NUMA PowerNV This was because we never clear the MMU_FTR_HPTE_TABLE feature flag even if we run with radix translation. It was discussed that we should look at this feature flag as an indication of the capability to run hash translation and we should not clear the flag even if we run in radix translation. All the code paths check for radix_enabled() check and if found true consider we are running with radix translation. Follow the same sequence for finding the MMU translation string to be used in Oops message. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> Acked-by: Nicholas Piggin <npiggin@xxxxxxxxx> Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20190711145814.17970-1-aneesh.kumar@xxxxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/powerpc/kernel/traps.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index 82f43535e686..014ff0701f24 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -250,15 +250,22 @@ static void oops_end(unsigned long flags, struct pt_regs *regs, } NOKPROBE_SYMBOL(oops_end); +static char *get_mmu_str(void) +{ + if (early_radix_enabled()) + return " MMU=Radix"; + if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE)) + return " MMU=Hash"; + return ""; +} + static int __die(const char *str, struct pt_regs *regs, long err) { printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter); - printk("%s PAGE_SIZE=%luK%s%s%s%s%s%s%s %s\n", + printk("%s PAGE_SIZE=%luK%s%s%s%s%s%s %s\n", IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? "LE" : "BE", - PAGE_SIZE / 1024, - early_radix_enabled() ? " MMU=Radix" : "", - early_mmu_has_feature(MMU_FTR_HPTE_TABLE) ? " MMU=Hash" : "", + PAGE_SIZE / 1024, get_mmu_str(), IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "", IS_ENABLED(CONFIG_SMP) ? " SMP" : "", IS_ENABLED(CONFIG_SMP) ? (" NR_CPUS=" __stringify(NR_CPUS)) : "", -- 2.20.1
