From patchwork Mon Jun 6 07:48:13 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kefeng Wang X-Patchwork-Id: 12870095 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CAB75C433EF for ; Mon, 6 Jun 2022 07:40:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; 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Mon, 6 Jun 2022 15:38:38 +0800 Received: from localhost.localdomain.localdomain (10.175.113.25) by dggpemm500001.china.huawei.com (7.185.36.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Mon, 6 Jun 2022 15:38:37 +0800 From: Kefeng Wang To: , , , , CC: , , , , Kefeng Wang Subject: [PATCH v4 4/6] mm: ioremap: Add ioremap/iounmap_allowed() Date: Mon, 6 Jun 2022 15:48:13 +0800 Message-ID: <20220606074815.139265-5-wangkefeng.wang@huawei.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220606074815.139265-1-wangkefeng.wang@huawei.com> References: <20220606074815.139265-1-wangkefeng.wang@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.113.25] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpemm500001.china.huawei.com (7.185.36.107) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220606_003857_322051_E11746CF X-CRM114-Status: GOOD ( 12.85 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Add special hook for architecture to verify addr, size or prot when ioremap() or iounmap(), which will make the generic ioremap more useful. ioremap_allowed() return an int, - NULL means continue to remap - error code means skip remap and return directly iounmap_allowed() return an int, - 0 means continue to vunmap - error code means skip vunmap and return directly Acked-by: Andrew Morton Signed-off-by: Kefeng Wang --- include/asm-generic/io.h | 25 +++++++++++++++++++++++++ mm/ioremap.c | 13 ++++++++++--- 2 files changed, 35 insertions(+), 3 deletions(-) diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h index e6ffa2519f08..9429387a3e65 100644 --- a/include/asm-generic/io.h +++ b/include/asm-generic/io.h @@ -964,6 +964,31 @@ static inline void iounmap(volatile void __iomem *addr) #elif defined(CONFIG_GENERIC_IOREMAP) #include +/* + * Arch code can implement the following two special hooks when using GENERIC_IOREMAP + * ioremap_allowed() return an int, + * - 0 means continue to remap + * - error code means skip remap and return directly + * iounmap_allowed() return an int, + * - 0 means continue to vunmap + * - error code means skip vunmap and return directly + */ +#ifndef ioremap_allowed +#define ioremap_allowed ioremap_allowed +static inline int ioremap_allowed(phys_addr_t phys_addr, size_t size, unsigned long prot) +{ + return 0; +} +#endif + +#ifndef iounmap_allowed +#define iounmap_allowed iounmap_allowed +static inline int iounmap_allowed(void __iomem *addr) +{ + return 0; +} +#endif + void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size, unsigned long prot); void iounmap(volatile void __iomem *addr); diff --git a/mm/ioremap.c b/mm/ioremap.c index 7cb9996b0c12..196c93c0beb8 100644 --- a/mm/ioremap.c +++ b/mm/ioremap.c @@ -27,8 +27,10 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size, unsigned long pro phys_addr -= offset; size = PAGE_ALIGN(size + offset); - area = get_vm_area_caller(size, VM_IOREMAP, - __builtin_return_address(0)); + if (ioremap_allowed(phys_addr, size, prot)) + return NULL; + + area = get_vm_area_caller(size, VM_IOREMAP, __builtin_return_address(0)); if (!area) return NULL; vaddr = (unsigned long)area->addr; @@ -45,6 +47,11 @@ EXPORT_SYMBOL(ioremap_prot); void iounmap(volatile void __iomem *addr) { - vunmap((void *)((unsigned long)addr & PAGE_MASK)); + void __iomem *vaddr = (void __iomem *)((unsigned long)addr & PAGE_MASK); + + if (iounmap_allowed(vaddr)) + return; + + vunmap((void __force *)vaddr); } EXPORT_SYMBOL(iounmap);