From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: From: Andrew Murray To: Arnd Bergmann , Will Deacon , yuanzhichang@hisilicon.com, dann.frazier@canonical.com, gabriele.paoloni@huawei.com, bhelgaas@google.com, andy.shevchenko@gmail.com Subject: [PATCH] asm-generic: io: Fix ioport_map() for !CONFIG_GENERIC_IOMAP && CONFIG_INDIRECT_PIO Date: Thu, 13 Sep 2018 13:48:27 +0100 Message-Id: <1536842907-51732-1-git-send-email-andrew.murray@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jean-philippe.brucker@arm.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, suzuki.poulose@arm.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+bjorn=helgaas.com@lists.infradead.org List-ID: The !CONFIG_GENERIC_IOMAP version of ioport_map uses MMIO_UPPER_LIMIT to prevent users from making I/O accesses outside the expected I/O range - however it erroneously treats MMIO_UPPER_LIMIT as a mask which is contradictory to its other users. The introduction of CONFIG_INDIRECT_PIO, which subtracts an arbitrary amount from IO_SPACE_LIMIT to form MMIO_UPPER_LIMIT, results in ioport_map mangling the given port rather than capping it. We address this by aligning more closely with the CONFIG_GENERIC_IOMAP implementation of ioport_map by using the comparison operator and returning NULL where the port exceeds MMIO_UPPER_LIMIT. Though note that we preserve the existing behavior of masking with IO_SPACE_LIMIT such that we don't break existing buggy drivers that somehow rely on this masking. Fixes: 5745392e0c2b ("PCI: Apply the new generic I/O management on PCI IO hosts") Reported-by: Will Deacon Signed-off-by: Andrew Murray --- include/asm-generic/io.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h index 66d1d45..d356f80 100644 --- a/include/asm-generic/io.h +++ b/include/asm-generic/io.h @@ -1026,7 +1026,8 @@ static inline void __iomem *ioremap_wt(phys_addr_t offset, size_t size) #define ioport_map ioport_map static inline void __iomem *ioport_map(unsigned long port, unsigned int nr) { - return PCI_IOBASE + (port & MMIO_UPPER_LIMIT); + port &= IO_SPACE_LIMIT; + return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port; } #endif -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel