From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f46.google.com (mail-wg0-f46.google.com [74.125.82.46]) by kanga.kvack.org (Postfix) with ESMTP id 15F3F6B0071 for ; Wed, 6 May 2015 13:50:58 -0400 (EDT) Received: by wgiu9 with SMTP id u9so19808623wgi.3 for ; Wed, 06 May 2015 10:50:57 -0700 (PDT) Received: from e06smtp10.uk.ibm.com (e06smtp10.uk.ibm.com. [195.75.94.106]) by mx.google.com with ESMTPS id lp9si1219817wjb.129.2015.05.06.10.50.49 for (version=TLSv1 cipher=AES128-SHA bits=128/128); Wed, 06 May 2015 10:50:50 -0700 (PDT) Received: from /spool/local by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 6 May 2015 18:50:49 +0100 Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by d06dlp03.portsmouth.uk.ibm.com (Postfix) with ESMTP id 6D8D91B08078 for ; Wed, 6 May 2015 18:51:29 +0100 (BST) Received: from d06av05.portsmouth.uk.ibm.com (d06av05.portsmouth.uk.ibm.com [9.149.37.229]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t46Hok2Z5570900 for ; Wed, 6 May 2015 17:50:46 GMT Received: from d06av05.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av05.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t46Hojc4027580 for ; Wed, 6 May 2015 11:50:46 -0600 From: David Hildenbrand Subject: [PATCH RFC 05/15] mips: kmap_coherent relies on disabled preemption Date: Wed, 6 May 2015 19:50:29 +0200 Message-Id: <1430934639-2131-6-git-send-email-dahi@linux.vnet.ibm.com> In-Reply-To: <1430934639-2131-1-git-send-email-dahi@linux.vnet.ibm.com> References: <1430934639-2131-1-git-send-email-dahi@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: dahi@linux.vnet.ibm.com, mingo@redhat.com, peterz@infradead.org, yang.shi@windriver.com, bigeasy@linutronix.de, benh@kernel.crashing.org, paulus@samba.org, akpm@linux-foundation.org, heiko.carstens@de.ibm.com, schwidefsky@de.ibm.com, borntraeger@de.ibm.com, mst@redhat.com, tglx@linutronix.de, David.Laight@ACULAB.COM, hughd@google.com, hocko@suse.cz, ralf@linux-mips.org, herbert@gondor.apana.org.au, linux@arm.linux.org.uk, airlied@linux.ie, daniel.vetter@intel.com, linux-mm@kvack.org, linux-arch@vger.kernel.org k(un)map_coherent relies on pagefault_disable() to also disable preemption. Let's make this explicit, to prepare for pagefault_disable() not touching preemption anymore. This patch is based on a patch by Yang Shi on the -rt tree: "k{un}map_coherent are just called when cpu_has_dc_aliases == 1 with VIPT cache. However, actually, the most modern MIPS processors have PIPT dcache without dcache alias issue. In such case, k{un}map_atomic will be called with preempt enabled." Signed-off-by: David Hildenbrand --- arch/mips/mm/init.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c index faa5c98..198a314 100644 --- a/arch/mips/mm/init.c +++ b/arch/mips/mm/init.c @@ -90,6 +90,7 @@ static void *__kmap_pgprot(struct page *page, unsigned long addr, pgprot_t prot) BUG_ON(Page_dcache_dirty(page)); + preempt_disable(); pagefault_disable(); idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1); idx += in_interrupt() ? FIX_N_COLOURS : 0; @@ -152,6 +153,7 @@ void kunmap_coherent(void) write_c0_entryhi(old_ctx); local_irq_restore(flags); pagefault_enable(); + preempt_enable(); } void copy_user_highpage(struct page *to, struct page *from, -- 2.1.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org