From 8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Tue, 15 Dec 2015 14:52:16 -0300 Subject: Linux-libre 4.3.2-gnu --- arch/powerpc/mm/hash_native_64.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) (limited to 'arch/powerpc/mm/hash_native_64.c') diff --git a/arch/powerpc/mm/hash_native_64.c b/arch/powerpc/mm/hash_native_64.c index 13befa35d..c8822af10 100644 --- a/arch/powerpc/mm/hash_native_64.c +++ b/arch/powerpc/mm/hash_native_64.c @@ -582,13 +582,21 @@ static void hpte_decode(struct hash_pte *hpte, unsigned long slot, * be when they isi), and we are the only one left. We rely on our kernel * mapping being 0xC0's and the hardware ignoring those two real bits. * + * This must be called with interrupts disabled. + * + * Taking the native_tlbie_lock is unsafe here due to the possibility of + * lockdep being on. On pre POWER5 hardware, not taking the lock could + * cause deadlock. POWER5 and newer not taking the lock is fine. This only + * gets called during boot before secondary CPUs have come up and during + * crashdump and all bets are off anyway. + * * TODO: add batching support when enabled. remember, no dynamic memory here, * athough there is the control page available... */ static void native_hpte_clear(void) { unsigned long vpn = 0; - unsigned long slot, slots, flags; + unsigned long slot, slots; struct hash_pte *hptep = htab_address; unsigned long hpte_v; unsigned long pteg_count; @@ -596,13 +604,6 @@ static void native_hpte_clear(void) pteg_count = htab_hash_mask + 1; - local_irq_save(flags); - - /* we take the tlbie lock and hold it. Some hardware will - * deadlock if we try to tlbie from two processors at once. - */ - raw_spin_lock(&native_tlbie_lock); - slots = pteg_count * HPTES_PER_GROUP; for (slot = 0; slot < slots; slot++, hptep++) { @@ -614,8 +615,8 @@ static void native_hpte_clear(void) hpte_v = be64_to_cpu(hptep->v); /* - * Call __tlbie() here rather than tlbie() since we - * already hold the native_tlbie_lock. + * Call __tlbie() here rather than tlbie() since we can't take the + * native_tlbie_lock. */ if (hpte_v & HPTE_V_VALID) { hpte_decode(hptep, slot, &psize, &apsize, &ssize, &vpn); @@ -625,8 +626,6 @@ static void native_hpte_clear(void) } asm volatile("eieio; tlbsync; ptesync":::"memory"); - raw_spin_unlock(&native_tlbie_lock); - local_irq_restore(flags); } /* -- cgit v1.2.3-54-g00ecf