From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752959AbcKYId6 (ORCPT ); Fri, 25 Nov 2016 03:33:58 -0500 Received: from mx2.suse.de ([195.135.220.15]:45240 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753431AbcKYIdH (ORCPT ); Fri, 25 Nov 2016 03:33:07 -0500 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, "David S. Miller" , Jiri Slaby Subject: [PATCH 3.12 113/127] sparc64: Handle extremely large kernel TSB range flushes sanely. Date: Fri, 25 Nov 2016 09:30:26 +0100 Message-Id: <72c18e0a4691e69c781c9d6e1dda6b1748adbcb6.1480062521.git.jslaby@suse.cz> X-Mailer: git-send-email 2.10.2 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "David S. Miller" 3.12-stable review patch. If anyone has any objections, please let me know. =============== [ Upstream commit 849c498766060a16aad5b0e0d03206726e7d2fa4 ] If the number of pages we are flushing is more than twice the number of entries in the TSB, just scan the TSB table for matches rather than probing each and every page in the range. Based upon a patch and report by James Clarke. Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby --- arch/sparc/mm/tsb.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/arch/sparc/mm/tsb.c b/arch/sparc/mm/tsb.c index 12f172117043..48a09e48d444 100644 --- a/arch/sparc/mm/tsb.c +++ b/arch/sparc/mm/tsb.c @@ -26,6 +26,20 @@ static inline int tag_compare(unsigned long tag, unsigned long vaddr) return (tag == (vaddr >> 22)); } +static void flush_tsb_kernel_range_scan(unsigned long start, unsigned long end) +{ + unsigned long idx; + + for (idx = 0; idx < KERNEL_TSB_NENTRIES; idx++) { + struct tsb *ent = &swapper_tsb[idx]; + unsigned long match = idx << 13; + + match |= (ent->tag << 22); + if (match >= start && match < end) + ent->tag = (1UL << TSB_TAG_INVALID_BIT); + } +} + /* TSB flushes need only occur on the processor initiating the address * space modification, not on each cpu the address space has run on. * Only the TLB flush needs that treatment. @@ -35,6 +49,9 @@ void flush_tsb_kernel_range(unsigned long start, unsigned long end) { unsigned long v; + if ((end - start) >> PAGE_SHIFT >= 2 * KERNEL_TSB_NENTRIES) + return flush_tsb_kernel_range_scan(start, end); + for (v = start; v < end; v += PAGE_SIZE) { unsigned long hash = tsb_hash(v, PAGE_SHIFT, KERNEL_TSB_NENTRIES); -- 2.10.2