diff options
Diffstat (limited to 'arch/powerpc/platforms/85xx/smp.c')
| -rw-r--r-- | arch/powerpc/platforms/85xx/smp.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c index 5ced4f5bb2b2..281b7f01df63 100644 --- a/arch/powerpc/platforms/85xx/smp.c +++ b/arch/powerpc/platforms/85xx/smp.c @@ -69,7 +69,32 @@ static void mpc85xx_give_timebase(void) tb_req = 0; mpc85xx_timebase_freeze(1); +#ifdef CONFIG_PPC64 + /* + * e5500/e6500 have a workaround for erratum A-006958 in place + * that will reread the timebase until TBL is non-zero. + * That would be a bad thing when the timebase is frozen. + * + * Thus, we read it manually, and instead of checking that + * TBL is non-zero, we ensure that TB does not change. We don't + * do that for the main mftb implementation, because it requires + * a scratch register + */ + { + u64 prev; + + asm volatile("mfspr %0, %1" : "=r" (timebase) : + "i" (SPRN_TBRL)); + + do { + prev = timebase; + asm volatile("mfspr %0, %1" : "=r" (timebase) : + "i" (SPRN_TBRL)); + } while (prev != timebase); + } +#else timebase = get_tb(); +#endif mb(); tb_valid = 1; @@ -255,6 +280,7 @@ out: struct smp_ops_t smp_85xx_ops = { .kick_cpu = smp_85xx_kick_cpu, + .cpu_bootable = smp_generic_cpu_bootable, #ifdef CONFIG_HOTPLUG_CPU .cpu_disable = generic_cpu_disable, .cpu_die = generic_cpu_die, |