Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965373AbeALVYq (ORCPT + 1 other); Fri, 12 Jan 2018 16:24:46 -0500 Received: from mail-pg0-f66.google.com ([74.125.83.66]:43428 "EHLO mail-pg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965306AbeALVYl (ORCPT ); Fri, 12 Jan 2018 16:24:41 -0500 X-Google-Smtp-Source: ACJfBotTghZx3jIRSm5bRooOMWl8Mj5XypcEo81lnAoyIffm5SbUknOvCU0giQ8v01+WQ/90obCtnA== From: Derek Basehore To: linux-kernel@vger.kernel.org Cc: linux-pm@vger.kernel.org, rafael.j.wysocki@intel.com, tglx@linutronix.de, briannorris@chromium.org, marc.zyngier@arm.com, Derek Basehore Subject: [PATCH 2/8] lib/iomap_copy: add __ioread64_copy() Date: Fri, 12 Jan 2018 13:24:16 -0800 Message-Id: <20180112212422.148625-3-dbasehore@chromium.org> X-Mailer: git-send-email 2.16.0.rc1.238.g530d649a79-goog In-Reply-To: <20180112212422.148625-1-dbasehore@chromium.org> References: <20180112212422.148625-1-dbasehore@chromium.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: Some drivers will want to read IO memory 64 bits at a time. Add an API for this. The 64-bit vs. 32-bit behavior is the same as the existing __iowrite64_copy(), where we don't expect to need to (or be able to) write in 64-bit chunks, so we fall back to a 32-bit equivalent. Change-Id: Ia681f60bb98a0c6107052bccbeb5032861a93a0b Signed-off-by: Derek Basehore Signed-off-by: Brian Norris --- include/linux/io.h | 1 + lib/iomap_copy.c | 26 ++++++++++++++++++++++++++ 2 files changed, 27 insertions(+) diff --git a/include/linux/io.h b/include/linux/io.h index 32e30e8fb9db..53c34a0d65f7 100644 --- a/include/linux/io.h +++ b/include/linux/io.h @@ -31,6 +31,7 @@ struct resource; __visible void __iowrite32_copy(void __iomem *to, const void *from, size_t count); void __ioread32_copy(void *to, const void __iomem *from, size_t count); void __iowrite64_copy(void __iomem *to, const void *from, size_t count); +void __ioread64_copy(void *to, const void __iomem *from, size_t count); #ifdef CONFIG_MMU int ioremap_page_range(unsigned long addr, unsigned long end, diff --git a/lib/iomap_copy.c b/lib/iomap_copy.c index b8f1d6cbb200..71c137ede5fb 100644 --- a/lib/iomap_copy.c +++ b/lib/iomap_copy.c @@ -89,3 +89,29 @@ void __attribute__((weak)) __iowrite64_copy(void __iomem *to, } EXPORT_SYMBOL_GPL(__iowrite64_copy); + +/** + * __ioread64_copy - copy data from MMIO space, in 64-bit units + * @to: destination (must be 64-bit aligned) + * @from: source, in MMIO space (must be 64-bit aligned) + * @count: number of 64-bit quantities to copy + * + * Copy data from MMIO space to kernel space, in units of 64 bits at a time if + * on a 64-bit system. 32-bit systems will fall back to 32 bits at a time. + * Order of access is not guaranteed, nor is a memory barrier performed + * afterwards. + */ +void __ioread64_copy(void *to, const void __iomem *from, size_t count) +{ +#ifdef CONFIG_64BIT + u64 *dst = to; + const u64 __iomem *src = from; + const u64 __iomem *end = src + count; + + while (src < end) + *dst++ = __raw_readq(src++); +#else + __ioread32_copy(to, from, count * 2); +#endif +} +EXPORT_SYMBOL_GPL(__ioread64_copy); -- 2.16.0.rc1.238.g530d649a79-goog