powerpc/mm/thp: Use tlbiel if possible
If we know that user address space has never executed on other cpus
we could use tlbiel.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 6c2076c..68211d3 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -1317,7 +1317,7 @@
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
void flush_hash_hugepage(unsigned long vsid, unsigned long addr,
- pmd_t *pmdp, unsigned int psize, int ssize)
+ pmd_t *pmdp, unsigned int psize, int ssize, int local)
{
int i, max_hpte_count, valid;
unsigned long s_addr;
@@ -1334,9 +1334,11 @@
if (!hpte_slot_array)
return;
- if (ppc_md.hugepage_invalidate)
- return ppc_md.hugepage_invalidate(vsid, s_addr, hpte_slot_array,
- psize, ssize);
+ if (ppc_md.hugepage_invalidate) {
+ ppc_md.hugepage_invalidate(vsid, s_addr, hpte_slot_array,
+ psize, ssize, local);
+ goto tm_abort;
+ }
/*
* No bluk hpte removal support, invalidate each entry
*/
@@ -1362,8 +1364,24 @@
slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
slot += hidx & _PTEIDX_GROUP_IX;
ppc_md.hpte_invalidate(slot, vpn, psize,
- MMU_PAGE_16M, ssize, 0);
+ MMU_PAGE_16M, ssize, local);
}
+tm_abort:
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+ /* Transactions are not aborted by tlbiel, only tlbie.
+ * Without, syncing a page back to a block device w/ PIO could pick up
+ * transactional data (bad!) so we force an abort here. Before the
+ * sync the page will be made read-only, which will flush_hash_page.
+ * BIG ISSUE here: if the kernel uses a page from userspace without
+ * unmapping it first, it may see the speculated version.
+ */
+ if (local && cpu_has_feature(CPU_FTR_TM) &&
+ current->thread.regs &&
+ MSR_TM_ACTIVE(current->thread.regs->msr)) {
+ tm_enable();
+ tm_abort(TM_CAUSE_TLBI);
+ }
+#endif
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */