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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-12-15 14:52:16 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-12-15 14:52:16 -0300
commit8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be (patch)
treee9891aa6c295060d065adffd610c4f49ecf884f3 /arch/powerpc/mm/hash_native_64.c
parenta71852147516bc1cb5b0b3cbd13639bfd4022dc8 (diff)
Linux-libre 4.3.2-gnu
Diffstat (limited to 'arch/powerpc/mm/hash_native_64.c')
-rw-r--r--arch/powerpc/mm/hash_native_64.c23
1 files changed, 11 insertions, 12 deletions
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);
}
/*