{"id":812743,"url":"http://patchwork.ozlabs.org/api/patches/812743/?format=json","web_url":"http://patchwork.ozlabs.org/project/ubuntu-kernel/patch/1505209542-17445-3-git-send-email-stefan.bader@canonical.com/","project":{"id":15,"url":"http://patchwork.ozlabs.org/api/projects/15/?format=json","name":"Ubuntu Kernel","link_name":"ubuntu-kernel","list_id":"kernel-team.lists.ubuntu.com","list_email":"kernel-team@lists.ubuntu.com","web_url":null,"scm_url":null,"webscm_url":null,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<1505209542-17445-3-git-send-email-stefan.bader@canonical.com>","list_archive_url":null,"date":"2017-09-12T09:45:39","name":"[Xenial,2/3] UBUNTU: SAUCE: s390/mm: fix local TLB flushing vs. detach of an mm address space","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"cd42440d4a833c5375625383db0f581c8c626903","submitter":{"id":2898,"url":"http://patchwork.ozlabs.org/api/people/2898/?format=json","name":"Stefan Bader","email":"stefan.bader@canonical.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/ubuntu-kernel/patch/1505209542-17445-3-git-send-email-stefan.bader@canonical.com/mbox/","series":[{"id":2646,"url":"http://patchwork.ozlabs.org/api/series/2646/?format=json","web_url":"http://patchwork.ozlabs.org/project/ubuntu-kernel/list/?series=2646","date":"2017-09-12T09:45:39","name":null,"version":1,"mbox":"http://patchwork.ozlabs.org/series/2646/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/812743/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/812743/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":"ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=lists.ubuntu.com\n\t(client-ip=91.189.94.19; helo=huckleberry.canonical.com;\n\tenvelope-from=kernel-team-bounces@lists.ubuntu.com;\n\treceiver=)","Received":["from huckleberry.canonical.com (huckleberry.canonical.com\n\t[91.189.94.19])\n\tby ozlabs.org (Postfix) with ESMTP id 3xs0KX5PjQz9sRg;\n\tTue, 12 Sep 2017 19:45:52 +1000 (AEST)","from localhost ([127.0.0.1] helo=huckleberry.canonical.com)\n\tby huckleberry.canonical.com with esmtp (Exim 4.86_2)\n\t(envelope-from )\n\tid 1drhlK-0003Qx-Ul; Tue, 12 Sep 2017 09:45:46 +0000","from youngberry.canonical.com ([91.189.89.112])\n\tby huckleberry.canonical.com with esmtps\n\t(TLS1.0:DHE_RSA_AES_128_CBC_SHA1:128)\n\t(Exim 4.86_2) (envelope-from )\n\tid 1drhlH-0003Oz-ML\n\tfor kernel-team@lists.ubuntu.com; Tue, 12 Sep 2017 09:45:43 +0000","from 1.general.smb.uk.vpn ([10.172.193.28] helo=canonical.com)\n\tby youngberry.canonical.com with esmtpsa\n\t(TLS1.0:RSA_AES_128_CBC_SHA1:16)\n\t(Exim 4.76) (envelope-from )\n\tid 1drhlH-0006U9-Ds\n\tfor kernel-team@lists.ubuntu.com; Tue, 12 Sep 2017 09:45:43 +0000"],"From":"Stefan Bader ","To":"kernel-team@lists.ubuntu.com","Subject":"[Xenial PATCH 2/3] UBUNTU: SAUCE: s390/mm: fix local TLB flushing\n\tvs. detach of an mm address space","Date":"Tue, 12 Sep 2017 11:45:39 +0200","Message-Id":"<1505209542-17445-3-git-send-email-stefan.bader@canonical.com>","X-Mailer":"git-send-email 2.7.4","In-Reply-To":"<1505209542-17445-1-git-send-email-stefan.bader@canonical.com>","References":"<1505209542-17445-1-git-send-email-stefan.bader@canonical.com>","X-BeenThere":"kernel-team@lists.ubuntu.com","X-Mailman-Version":"2.1.20","Precedence":"list","List-Id":"Kernel team discussions ","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","MIME-Version":"1.0","Content-Type":"text/plain; charset=\"utf-8\"","Content-Transfer-Encoding":"base64","Errors-To":"kernel-team-bounces@lists.ubuntu.com","Sender":"\"kernel-team\" "},"content":"From: Martin Schwidefsky \n\nBugLink: http://bugs.launchpad.net/bugs/1708399\n\nThe local TLB flushing code keeps an additional mask in the mm.context,\nthe cpu_attach_mask. At the time a global flush of an address space is\ndone the cpu_attach_mask is copied to the mm_cpumask in order to avoid\nfuture global flushes in case the mm is used by a single CPU only after\nthe flush.\n\nTrouble is that the reset of the mm_cpumask is racy against the detach\nof an mm address space by switch_mm. The current order is first the\nglobal TLB flush and then the copy of the cpu_attach_mask to the\nmm_cpumask. The order needs to be the other way around.\n\nCc: \nReviewed-by: Heiko Carstens \nSigned-off-by: Martin Schwidefsky \n(backported from b3e5dc45fd1ec2aa1de6b80008f9295eb17e0659 linux-next)\n[merged with \"s390/mm,kvm: flush gmap address space with IDTE\"]\nSigned-off-by: Stefan Bader \n---\n arch/s390/include/asm/tlbflush.h | 56 ++++++++++++----------------------------\n 1 file changed, 16 insertions(+), 40 deletions(-)","diff":"diff --git a/arch/s390/include/asm/tlbflush.h b/arch/s390/include/asm/tlbflush.h\nindex 80868c84..d54cc83 100644\n--- a/arch/s390/include/asm/tlbflush.h\n+++ b/arch/s390/include/asm/tlbflush.h\n@@ -47,47 +47,31 @@ static inline void __tlb_flush_global(void)\n }\n \n /*\n- * Flush TLB entries for a specific mm on all CPUs (in case gmap is used\n- * this implicates multiple ASCEs!).\n+ * Flush TLB entries for a specific ASCE on all CPUs.\n */\n-static inline void __tlb_flush_full(struct mm_struct *mm)\n+static inline void __tlb_flush_mm(struct mm_struct * mm)\n {\n+\t/*\n+\t * If the machine has IDTE we prefer to do a per mm flush\n+\t * on all cpus instead of doing a local flush if the mm\n+\t * only ran on the local cpu.\n+\t */\n \tpreempt_disable();\n \tatomic_add(0x10000, &mm->context.attach_count);\n-\tif (cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id()))) {\n-\t\t/* Local TLB flush */\n-\t\t__tlb_flush_local();\n+\t/* Reset TLB flush mask */\n+\tif (MACHINE_HAS_TLB_LC)\n+\t\tcpumask_copy(mm_cpumask(mm), &mm->context.cpu_attach_mask);\n+\tbarrier();\n+\tif (MACHINE_HAS_IDTE && list_empty(&mm->context.gmap_list)) {\n+\t\t__tlb_flush_idte(mm->context.asce);\n \t} else {\n \t\t/* Global TLB flush */\n \t\t__tlb_flush_global();\n-\t\t/* Reset TLB flush mask */\n-\t\tif (MACHINE_HAS_TLB_LC)\n-\t\t\tcpumask_copy(mm_cpumask(mm),\n-\t\t\t\t &mm->context.cpu_attach_mask);\n \t}\n \tatomic_sub(0x10000, &mm->context.attach_count);\n \tpreempt_enable();\n }\n \n-/*\n- * Flush TLB entries for a specific ASCE on all CPUs. Should never be used\n- * when more than one asce (e.g. gmap) ran on this mm.\n- */\n-static inline void __tlb_flush_asce(struct mm_struct *mm, unsigned long asce)\n-{\n-\tpreempt_disable();\n-\tatomic_add(0x10000, &mm->context.attach_count);\n-\tif (MACHINE_HAS_IDTE)\n-\t\t__tlb_flush_idte(asce);\n-\telse\n-\t\t__tlb_flush_global();\n-\t/* Reset TLB flush mask */\n-\tif (MACHINE_HAS_TLB_LC)\n-\t\tcpumask_copy(mm_cpumask(mm), &mm->context.cpu_attach_mask);\n-\tatomic_sub(0x10000, &mm->context.attach_count);\n-\tpreempt_enable();\n-}\n-\n static inline void __tlb_flush_kernel(void)\n {\n \tif (MACHINE_HAS_IDTE)\n@@ -97,7 +81,6 @@ static inline void __tlb_flush_kernel(void)\n }\n #else\n #define __tlb_flush_global()\t__tlb_flush_local()\n-#define __tlb_flush_full(mm)\t__tlb_flush_local()\n \n /*\n * Flush TLB entries for a specific ASCE on all CPUs.\n@@ -111,21 +94,14 @@ static inline void __tlb_flush_kernel(void)\n {\n \t__tlb_flush_local();\n }\n-#endif\n \n static inline void __tlb_flush_mm(struct mm_struct * mm)\n {\n-\t/*\n-\t * If the machine has IDTE we prefer to do a per mm flush\n-\t * on all cpus instead of doing a local flush if the mm\n-\t * only ran on the local cpu.\n-\t */\n-\tif (MACHINE_HAS_IDTE && list_empty(&mm->context.gmap_list))\n-\t\t__tlb_flush_asce(mm, mm->context.asce);\n-\telse\n-\t\t__tlb_flush_full(mm);\n+\t__tlb_flush_local();\n }\n \n+#endif\n+\n static inline void __tlb_flush_mm_lazy(struct mm_struct * mm)\n {\n \tif (mm->context.flush_mm) {\n","prefixes":["Xenial","2/3"]}