[PATCH] ppc64 kexec: native hash clear
Add code to clear the hash table and invalidate the tlb for native (SMP,
non-LPAR) mode. Supports 16M and 4k pages.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: R Sharada <sharada@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/ppc64/mm/hash_native.c b/arch/ppc64/mm/hash_native.c
index 52b6b93..4fec058 100644
--- a/arch/ppc64/mm/hash_native.c
+++ b/arch/ppc64/mm/hash_native.c
@@ -304,6 +304,50 @@
local_irq_restore(flags);
}
+/*
+ * clear all mappings on kexec. All cpus are in real mode (or they will
+ * 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.
+ *
+ * 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 slot, slots, flags;
+ HPTE *hptep = htab_address;
+ Hpte_dword0 dw0;
+ unsigned long pteg_count;
+
+ 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.
+ */
+ spin_lock(&native_tlbie_lock);
+
+ slots = pteg_count * HPTES_PER_GROUP;
+
+ for (slot = 0; slot < slots; slot++, hptep++) {
+ /*
+ * we could lock the pte here, but we are the only cpu
+ * running, right? and for crash dump, we probably
+ * don't want to wait for a maybe bad cpu.
+ */
+ dw0 = hptep->dw0.dw0;
+
+ if (dw0.v) {
+ hptep->dw0.dword0 = 0;
+ tlbie(slot2va(dw0.avpn, dw0.l, dw0.h, slot), dw0.l);
+ }
+ }
+
+ spin_unlock(&native_tlbie_lock);
+ local_irq_restore(flags);
+}
+
static void native_flush_hash_range(unsigned long context,
unsigned long number, int local)
{
@@ -415,7 +459,8 @@
ppc_md.hpte_updatepp = native_hpte_updatepp;
ppc_md.hpte_updateboltedpp = native_hpte_updateboltedpp;
ppc_md.hpte_insert = native_hpte_insert;
- ppc_md.hpte_remove = native_hpte_remove;
+ ppc_md.hpte_remove = native_hpte_remove;
+ ppc_md.hpte_clear_all = native_hpte_clear;
if (tlb_batching_enabled())
ppc_md.flush_hash_range = native_flush_hash_range;
htab_finish_init();
diff --git a/include/asm-ppc64/mmu.h b/include/asm-ppc64/mmu.h
index 9d03a98..f373de5 100644
--- a/include/asm-ppc64/mmu.h
+++ b/include/asm-ppc64/mmu.h
@@ -181,6 +181,28 @@
asm volatile("ptesync": : :"memory");
}
+static inline unsigned long slot2va(unsigned long avpn, unsigned long large,
+ unsigned long secondary, unsigned long slot)
+{
+ unsigned long va;
+
+ va = avpn << 23;
+
+ if (!large) {
+ unsigned long vpi, pteg;
+
+ pteg = slot / HPTES_PER_GROUP;
+ if (secondary)
+ pteg = ~pteg;
+
+ vpi = ((va >> 28) ^ pteg) & htab_hash_mask;
+
+ va |= vpi << PAGE_SHIFT;
+ }
+
+ return va;
+}
+
/*
* Handle a fault by adding an HPTE. If the address can't be determined
* to be valid via Linux page tables, return 1. If handled return 0