From patchwork Fri Dec 1 12:16:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Philipp Stanner X-Patchwork-Id: 13475755 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="BO162Ot2" Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 596E110D7 for ; Fri, 1 Dec 2023 04:17:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1701433025; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=aIU4mh01NIo3J+0bv0Z7Ok8zfrU9Sy5KFoYboE67XEg=; b=BO162Ot2r3i6t0D+IGJdiws8Uq+tp8nza+hMHsmiaTi2+AD+9DOJTw6hCpI3NOHv5BUaZ/ JRc46Xc901oygR5M39Ckr8C+fe1G934lkf7p+owHYvT5OdXl1v8W95YuIuPNKidfp0uSRo CQo9hKpX9vLHa6JpL0YVpldIkoAIr8U= Received: from mail-qt1-f198.google.com (mail-qt1-f198.google.com [209.85.160.198]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-99-5BaqsDxtP4ueuAQbsd1SeQ-1; Fri, 01 Dec 2023 07:17:04 -0500 X-MC-Unique: 5BaqsDxtP4ueuAQbsd1SeQ-1 Received: by mail-qt1-f198.google.com with SMTP id d75a77b69052e-423c28eababso5306581cf.1 for ; Fri, 01 Dec 2023 04:17:04 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701433023; x=1702037823; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=aIU4mh01NIo3J+0bv0Z7Ok8zfrU9Sy5KFoYboE67XEg=; b=tXOIN5QC/L5X6IP78Ywg7xlZA2SguyuSAYKAX5qzIKwy9hpAelZwSvO0ptOLWNVNFq HG04At0vdCF4ld5W1sDmibIpErPmRyJxc0JSwqyUoMZNNW+RcpI4fAK4wYljkh5IBKwp ou329hlLFgqgHAhw0xyslDaYcbgmxrkildRbDaz6PeLZLdwJfvwtQJ7TIpjK1QAAhi77 B1TubGhfG3RfGbnk48lYLibPkiPrINFTOc8L/B8+fZLi3uglG/oVgF0u5+8h8ER0NLQp 6AF9mWT3C+YZBDgdpwHyN4m521E5JLiUbXLn/UU1jP0O0baK9jvUGrQ9WEe9CrlP6p3U ZUrQ== X-Gm-Message-State: AOJu0YyzrR+YmeF0hlwb8iOOb6HPna1tXb3J+jItNMDJ6xu1Pm5skr5A GemdD6XHClJUTcW1fj3JXSTd1/XHsA+KLbV6wcbc8ZDTzx/tMM5MvRP54Q7CPuFrRo4pOIj2zLO 0PJxYK6UjkK1RH1/yctvT X-Received: by 2002:a05:622a:5505:b0:423:a6c8:7db9 with SMTP id fj5-20020a05622a550500b00423a6c87db9mr24035878qtb.6.1701433023439; Fri, 01 Dec 2023 04:17:03 -0800 (PST) X-Google-Smtp-Source: AGHT+IFQfSS2UW2A54VtKLLtAF4bxHgHalN5nM46dpZI44qbzDLU3S4OQPiukfxEaRXrK+nRrdI9pQ== X-Received: by 2002:a05:622a:5505:b0:423:a6c8:7db9 with SMTP id fj5-20020a05622a550500b00423a6c87db9mr24035847qtb.6.1701433023157; Fri, 01 Dec 2023 04:17:03 -0800 (PST) Received: from pstanner-thinkpadt14sgen1.remote.csb ([2001:9e8:32e2:4e00:227b:d2ff:fe26:2a7a]) by smtp.gmail.com with ESMTPSA id b19-20020ac87553000000b00423b8a53641sm1426528qtr.29.2023.12.01.04.16.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 01 Dec 2023 04:17:02 -0800 (PST) From: Philipp Stanner To: Bjorn Helgaas , Arnd Bergmann , Andrew Morton , Dan Williams , Jonathan Cameron , Jakub Kicinski , Dave Jiang , Uladzislau Koshchanka , NeilBrown , Niklas Schnelle , John Sanpe , Kent Overstreet , Philipp Stanner , "Masami Hiramatsu (Google)" , Kees Cook , David Gow , Yury Norov , "wuqiang.matt" , Jason Baron , Kefeng Wang , Ben Dooks , dakr@redhat.com Cc: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-arch@vger.kernel.org, Arnd Bergmann Subject: [PATCH v2 4/4] lib, pci: unify generic pci_iounmap() Date: Fri, 1 Dec 2023 13:16:22 +0100 Message-ID: <20231201121622.16343-5-pstanner@redhat.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231201121622.16343-1-pstanner@redhat.com> References: <20231201121622.16343-1-pstanner@redhat.com> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The implementation of pci_iounmap() is currently scattered over two files, drivers/pci/iounmap.c and lib/iomap.c. Additionally, architectures can define their own version. Besides one unified version being desirable in the first place, the old version in drivers/pci/iounmap.c contained a bug and could leak memory mappings. The bug was that #ifdef ARCH_HAS_GENERIC_IOPORT_MAP should not have guarded iounmap(p); in addition to the preceding code. To have only one version, it's necessary to create a helper function, iomem_is_ioport(), that tells pci_iounmap() whether the passed address points to an ioport or normal memory. iomem_is_ioport() can be provided through three different ways: 1. The architecture itself provides it. 2. As a default version in include/asm-generic/io.h for those architectures that don't use CONFIG_GENERIC_IOMAP, but also don't provide their own version of iomem_is_ioport(). 3. As a default version in lib/iomap.c for those architectures that define and use CONFIG_GENERIC_IOMAP (currently, only x86 really uses the functions in lib/iomap.c) Create a unified version of pci_iounmap() in drivers/pci/iomap.c. Provide the function iomem_is_ioport() in include/asm-generic/io.h and lib/iomap.c. Remove the CONFIG_GENERIC_IOMAP guard around ARCH_WANTS_GENERIC_PCI_IOUNMAP so that configs that set CONFIG_GENERIC_PCI_IOMAP without CONFIG_GENERIC_IOMAP still get the function. Fixes: 316e8d79a095 ("pci_iounmap'2: Electric Boogaloo: try to make sense of it all") Suggested-by: Arnd Bergmann Signed-off-by: Philipp Stanner --- drivers/pci/iomap.c | 40 +++++++++++----------------------------- include/asm-generic/io.h | 37 ++++++++++++++++++++++++++++++++++--- lib/iomap.c | 16 +++++++++------- 3 files changed, 54 insertions(+), 39 deletions(-) diff --git a/drivers/pci/iomap.c b/drivers/pci/iomap.c index 0a9d503ba533..cb7f86371b7d 100644 --- a/drivers/pci/iomap.c +++ b/drivers/pci/iomap.c @@ -135,42 +135,24 @@ void __iomem *pci_iomap_wc(struct pci_dev *dev, int bar, unsigned long maxlen) EXPORT_SYMBOL_GPL(pci_iomap_wc); /* - * pci_iounmap() somewhat illogically comes from lib/iomap.c for the - * CONFIG_GENERIC_IOMAP case, because that's the code that knows about - * the different IOMAP ranges. + * Generic version of pci_iounmap() that is used if the architecture does not + * provide its own version. * - * But if the architecture does not use the generic iomap code, and if - * it has _not_ defined it's own private pci_iounmap function, we define - * it here. - * - * NOTE! This default implementation assumes that if the architecture - * support ioport mapping (HAS_IOPORT_MAP), the ioport mapping will - * be fixed to the range [ PCI_IOBASE, PCI_IOBASE+IO_SPACE_LIMIT [, - * and does not need unmapping with 'ioport_unmap()'. - * - * If you have different rules for your architecture, you need to - * implement your own pci_iounmap() that knows the rules for where - * and how IO vs MEM get mapped. - * - * This code is odd, and the ARCH_HAS/ARCH_WANTS #define logic comes - * from legacy header file behavior. In particular, - * it would seem to make sense to do the iounmap(p) for the non-IO-space - * case here regardless, but that's not what the old header file code - * did. Probably incorrectly, but this is meant to be bug-for-bug - * compatible. + * If you have special rules for your architecture, you need to implement your + * own pci_iounmap() in ARCH/asm/io.h that knows the rules for where and how IO + * vs MEM get mapped. */ #if defined(ARCH_WANTS_GENERIC_PCI_IOUNMAP) -void pci_iounmap(struct pci_dev *dev, void __iomem *p) +void pci_iounmap(struct pci_dev *dev, void __iomem *addr) { -#ifdef ARCH_HAS_GENERIC_IOPORT_MAP - uintptr_t start = (uintptr_t) PCI_IOBASE; - uintptr_t addr = (uintptr_t) p; - - if (addr >= start && addr < start + IO_SPACE_LIMIT) +#ifdef CONFIG_HAS_IOPORT + if (iomem_is_ioport(addr)) { + ioport_unmap(addr); return; - iounmap(p); + } #endif + iounmap(addr); } EXPORT_SYMBOL(pci_iounmap); diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h index bac63e874c7b..4177d6b97e0b 100644 --- a/include/asm-generic/io.h +++ b/include/asm-generic/io.h @@ -1129,11 +1129,42 @@ extern void ioport_unmap(void __iomem *p); #endif /* CONFIG_GENERIC_IOMAP */ #endif /* CONFIG_HAS_IOPORT_MAP */ -#ifndef CONFIG_GENERIC_IOMAP #ifndef pci_iounmap +#define pci_iounmap pci_iounmap #define ARCH_WANTS_GENERIC_PCI_IOUNMAP -#endif -#endif +#endif /* pci_iounmap */ + + +/* + * This function is a helper only needed for the generic pci_iounmap(). + * It's provided here if the architecture does not select GENERIC_IOMAP and does + * not provide its own version. + */ +#ifdef CONFIG_HAS_IOPORT +#ifndef iomem_is_ioport /* i.e., if the architecture hasn't defined its own. */ +#define iomem_is_ioport iomem_is_ioport + +#ifndef CONFIG_GENERIC_IOMAP +static inline bool iomem_is_ioport(void __iomem *addr) +{ + unsigned long port = (unsigned long __force)addr; + + // TODO: do we have to take IO_SPACE_LIMIT and PCI_IOBASE into account + // similar as in ioport_map() ? + + if (port > MMIO_UPPER_LIMIT) + return false; + + return true; +} +#else /* CONFIG_GENERIC_IOMAP. Version from lib/iomap.c will be used. */ +bool iomem_is_ioport(void __iomem *addr); +#define ARCH_WANTS_GENERIC_IOMEM_IS_IOPORT +#endif /* CONFIG_GENERIC_IOMAP */ + +#endif /* iomem_is_ioport */ +#endif /* CONFIG_HAS_IOPORT */ + #ifndef xlate_dev_mem_ptr #define xlate_dev_mem_ptr xlate_dev_mem_ptr diff --git a/lib/iomap.c b/lib/iomap.c index 4f8b31baa575..adaf6246f892 100644 --- a/lib/iomap.c +++ b/lib/iomap.c @@ -418,12 +418,14 @@ EXPORT_SYMBOL(ioport_map); EXPORT_SYMBOL(ioport_unmap); #endif /* CONFIG_HAS_IOPORT_MAP */ -#ifdef CONFIG_PCI -/* Hide the details if this is a MMIO or PIO address space and just do what - * you expect in the correct way. */ -void pci_iounmap(struct pci_dev *dev, void __iomem * addr) +#if defined(ARCH_WANTS_GENERIC_IOMEM_IS_IOPORT) +bool iomem_is_ioport(void __iomem *addr) { - IO_COND(addr, /* nothing */, iounmap(addr)); + unsigned long port = (unsigned long __force)addr; + + if (port > PIO_OFFSET && port < PIO_RESERVED) + return true; + + return false; } -EXPORT_SYMBOL(pci_iounmap); -#endif /* CONFIG_PCI */ +#endif /* ARCH_WANTS_GENERIC_IOMEM_IS_IOPORT */