[3.13.y.z extended stable] Patch "powerpc/thp: Invalidate with vpn in loop" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    powerpc/thp: Invalidate with vpn in loop

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.7.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From d8e32ccbd0766580a80c85efb203cb4469a86b7f Mon Sep 17 00:00:00 2001
From: "Aneesh Kumar K.V" <aneesh.kumar at linux.vnet.ibm.com>
Date: Wed, 13 Aug 2014 12:32:01 +0530
Subject: powerpc/thp: Invalidate with vpn in loop

commit 969b7b208f7408712a3526856e4ae60ad13f6928 upstream.

As per ISA, for 4k base page size we compare 14..65 bits of VA specified
with the entry_VA in tlb. That implies we need to make sure we do a
tlbie with all the possible 4k va we used to access the 16MB hugepage.
With 64k base page size we compare 14..57 bits of VA. Hence we cannot
ignore the lower 24 bits of va while tlbie .We also cannot tlb
invalidate a 16MB entry with just one tlbie instruction because
we don't track which va was used to instantiate the tlb entry.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 arch/powerpc/mm/hash_native_64.c | 23 +++++++----------------
 1 file changed, 7 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/mm/hash_native_64.c b/arch/powerpc/mm/hash_native_64.c
index 44886c2..838de8e 100644
--- a/arch/powerpc/mm/hash_native_64.c
+++ b/arch/powerpc/mm/hash_native_64.c
@@ -423,7 +423,7 @@ static void native_hugepage_invalidate(unsigned long vsid,
 				       unsigned char *hpte_slot_array,
 				       int psize, int ssize)
 {
-	int i, lock_tlbie;
+	int i;
 	struct hash_pte *hptep;
 	int actual_psize = MMU_PAGE_16M;
 	unsigned int max_hpte_count, valid;
@@ -462,22 +462,13 @@ static void native_hugepage_invalidate(unsigned long vsid,
 		else
 			/* Invalidate the hpte. NOTE: this also unlocks it */
 			hptep->v = 0;
+		/*
+		 * We need to do tlb invalidate for all the address, tlbie
+		 * instruction compares entry_VA in tlb with the VA specified
+		 * here
+		 */
+		tlbie(vpn, psize, actual_psize, ssize, 0);
 	}
-	/*
-	 * Since this is a hugepage, we just need a single tlbie.
-	 * use the last vpn.
-	 */
-	lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
-	if (lock_tlbie)
-		raw_spin_lock(&native_tlbie_lock);
-
-	asm volatile("ptesync":::"memory");
-	__tlbie(vpn, psize, actual_psize, ssize);
-	asm volatile("eieio; tlbsync; ptesync":::"memory");
-
-	if (lock_tlbie)
-		raw_spin_unlock(&native_tlbie_lock);
-
 	local_irq_restore(flags);
 }

--
1.9.1