Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752546AbaDOBVq (ORCPT ); Mon, 14 Apr 2014 21:21:46 -0400 Received: from mail-pd0-f171.google.com ([209.85.192.171]:37364 "EHLO mail-pd0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751019AbaDOBVo (ORCPT ); Mon, 14 Apr 2014 21:21:44 -0400 Message-ID: <534C899A.2020008@gmail.com> Date: Tue, 15 Apr 2014 09:21:30 +0800 From: Chen Gang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: =?UTF-8?B?566h6Zuq5rab?= CC: Guan Xuetao , akpm@linux-foundation.org, liuj97@gmail.com, rientjes@google.com, dhowells@redhat.com, mhocko@suse.cz, mgorman@suse.de, linux-kernel@vger.kernel.org Subject: [PATCH v3] arch:unicore32:mm: add devmem_is_allowed() to support STRICT_DEVMEM References: <629583968.18592.1396927216694.JavaMail.root@bj-mail03.pku.edu.cn> <534380F6.7090703@gmail.com> <534C79EE.3030505@gmail.com> <534C7D46.6040602@gmail.com> <534C8073.3060607@gmail.com> In-Reply-To: <534C8073.3060607@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org unicore32 supports STRICT_DEVMEM, so it needs devmem_is_allowed(), like some of other architectures have done (e.g. arm, powerpc, x86 ...). The related error with allmodconfig: CC drivers/char/mem.o drivers/char/mem.c: In function ‘range_is_allowed’: drivers/char/mem.c:69: error: implicit declaration of function ‘devmem_is_allowed’ make[2]: *** [drivers/char/mem.o] Error 1 make[1]: *** [drivers/char] Error 2 make: *** [drivers] Error 2 Signed-off-by: Chen Gang --- arch/unicore32/include/asm/io.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/arch/unicore32/include/asm/io.h b/arch/unicore32/include/asm/io.h index 39decb6..ae327e4 100644 --- a/arch/unicore32/include/asm/io.h +++ b/arch/unicore32/include/asm/io.h @@ -44,5 +44,28 @@ extern void __uc32_iounmap(volatile void __iomem *addr); #define PIO_MASK (unsigned int)(IO_SPACE_LIMIT) #define PIO_RESERVED (PIO_OFFSET + PIO_MASK + 1) +#ifdef CONFIG_STRICT_DEVMEM + +#include +#include + +/* + * devmem_is_allowed() checks to see if /dev/mem access to a certain + * address is valid. The argument is a physical page number. + * We mimic x86 here by disallowing access to system RAM as well as + * device-exclusive MMIO regions. This effectively disable read()/write() + * on /dev/mem. + */ +static inline int devmem_is_allowed(unsigned long pfn) +{ + if (iomem_is_exclusive(pfn << PAGE_SHIFT)) + return 0; + if (!page_is_ram(pfn)) + return 1; + return 0; +} + +#endif /* CONFIG_STRICT_DEVMEM */ + #endif /* __KERNEL__ */ #endif /* __UNICORE_IO_H__ */ -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/