From patchwork Fri Jun 16 21:28:06 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Fainelli X-Patchwork-Id: 9793743 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B9C8960231 for ; Fri, 16 Jun 2017 21:29:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AB2CD28671 for ; Fri, 16 Jun 2017 21:29:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9FDD32869C; Fri, 16 Jun 2017 21:29:21 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED,FREEMAIL_FROM,RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3FA5A28671 for ; Fri, 16 Jun 2017 21:29:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752484AbdFPV3D (ORCPT ); Fri, 16 Jun 2017 17:29:03 -0400 Received: from mail-qt0-f194.google.com ([209.85.216.194]:33066 "EHLO mail-qt0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752087AbdFPV2V (ORCPT ); Fri, 16 Jun 2017 17:28:21 -0400 Received: by mail-qt0-f194.google.com with SMTP id w1so12976424qtg.0; Fri, 16 Jun 2017 14:28:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=LWE8kmOiXgy5l0En/myQzzLhxAHTe88JghQN+j/4Hiw=; b=H8ndzca+3AhqUNFq0cNq9Ke5axNDcr+uQLMGUtZT0xx0LjLo6ZnZ3eWDxZM2Te/OrB OvEfVTcbFjwk3DXEXZjqrd004KgKx7yKf6gnOGPRz/il/L7veMJ4XBiuSpIWypPHjc64 TIEUd1hkQyTDEVRtQg1FIHKO+MTeHkDcMdyrl79Ol9KU7BSqo0G9TdKp2s6BWnkiJZ3B eKvHgnrGU3T2R5oz77bjlEnnvqFXbk4M3zoEP68fRNuaEZ5brtOqmRoC0/FSt6JucCOq 0dvjMP3lR6Y5gvT232lT9aysQkhYGVRmeAbhy+kouDgA56SDjc3k4rVxUPjiGBPGo73a kn5A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=LWE8kmOiXgy5l0En/myQzzLhxAHTe88JghQN+j/4Hiw=; b=UbS8hFRPtJPCiYQl6h+Ev6EzCZ8qG9vm1E+1RtoDHQEmSc+E1zwBaFnT/WYOm5VDTu rG0QWgVUmUlrPnMJiFsLCkIKiVmjyo7HnvZwvoPG8tb/zpSNWHMh9V4PqLXKjh0RO5Fw umWozpGQZGCMq9CGNCV40BrQJWqprPrE3FgYYqN0gA7ajkr01DPlXHdZ19J/RV5JpgXS dBKSZEvTImZ3gk3N+dpEcIYzrIxTqr3mgYAlDgxmJnEDrz0IAIaGpVolmoLIluEEUa7t Nng5hhSyegeebCb9ZDXmW6pSLX/4m/P531ocIbWwrLLfEJs7O6/lmjK9bGITlF3wl/Xs 5Kkw== X-Gm-Message-State: AKS2vOx4xCC8k4uJiNy/IEvOtmZ05NCj3uGEi2qWGYkcS6rHAkEbgyst TDzu0gBJN0o0YkuZChw= X-Received: by 10.237.46.34 with SMTP id j31mr15469077qtd.149.1497648499993; Fri, 16 Jun 2017 14:28:19 -0700 (PDT) Received: from fainelli-desktop.broadcom.com ([192.19.255.250]) by smtp.gmail.com with ESMTPSA id x32sm2381801qtc.37.2017.06.16.14.28.18 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 16 Jun 2017 14:28:19 -0700 (PDT) From: Florian Fainelli To: linux-arm-kernel@lists.infradead.org Cc: bcm-kernel-feedback-list@broadcom.com, Florian Fainelli , Russell King , Catalin Marinas , Will Deacon , Arnd Bergmann , Greg Kroah-Hartman , linux-kernel@vger.kernel.org (open list), linux-arch@vger.kernel.org (open list:GENERIC INCLUDE/ASM HEADER FILES), Dave Gerlach , Tony Lindgren , Keerthy J , Alexandre Belloni , linux-omap@vger.kernel.org, Shawn Guo Subject: [PATCH v2 2/4] asm-generic: Provide a fncpy() implementation Date: Fri, 16 Jun 2017 14:28:06 -0700 Message-Id: <20170616212808.19073-3-f.fainelli@gmail.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20170616212808.19073-1-f.fainelli@gmail.com> References: <20170616212808.19073-1-f.fainelli@gmail.com> Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Define a generic fncpy() implementation largely based on the ARM version that requires an 8 bytes alignment for the destination address where to copy this function as well as the function's own address. Signed-off-by: Florian Fainelli --- include/asm-generic/fncpy.h | 93 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) create mode 100644 include/asm-generic/fncpy.h diff --git a/include/asm-generic/fncpy.h b/include/asm-generic/fncpy.h new file mode 100644 index 000000000000..5bb3e5d20ae0 --- /dev/null +++ b/include/asm-generic/fncpy.h @@ -0,0 +1,93 @@ +/* + * include/asm-generic/fncpy.h - helper macros for function body copying + * + * Copyright (C) 2011 Linaro Limited + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +/* + * These macros are intended for use when there is a need to copy a low-level + * function body into special memory. + * + * For example, when reconfiguring the SDRAM controller, the code doing the + * reconfiguration may need to run from SRAM. + * + * NOTE: that the copied function body must be entirely self-contained and + * position-independent in order for this to work properly. + * + * NOTE: in order for embedded literals and data to get referenced correctly, + * the alignment of functions must be preserved when copying. To ensure this, + * the source and destination addresses for fncpy() must be aligned to a + * multiple of 8 bytes: you will be get a BUG() if this condition is not met. + * You will typically need a ".align 3" directive in the assembler where the + * function to be copied is defined, and ensure that your allocator for the + * destination buffer returns 8-byte-aligned pointers. + * + * Typical usage example: + * + * extern int f(args); + * extern uint32_t size_of_f; + * int (*copied_f)(args); + * void *sram_buffer; + * + * copied_f = fncpy(sram_buffer, &f, size_of_f); + * + * ... later, call the function: ... + * + * copied_f(args); + * + * The size of the function to be copied can't be determined from C: + * this must be determined by other means, such as adding assmbler directives + * in the file where f is defined. + */ + +#ifndef __ASM_ARM_FNCPY_H +#define __ASM_ARM_FNCPY_H + +#include +#include + +#include +#include + +/* + * Minimum alignment requirement for the source and destination addresses + * for function copying. + */ +#define FNCPY_ALIGN 8 + +#define fncpy(dest_buf, funcp, size) ({ \ + uintptr_t __funcp_address; \ + typeof(funcp) __result; \ + \ + asm("" : "=r" (__funcp_address) : "0" (funcp)); \ + \ + /* \ + * Ensure alignment of source and destination addresses. \ + */ \ + BUG_ON((uintptr_t)(dest_buf) & (FNCPY_ALIGN - 1) || \ + (__funcp_address & (FNCPY_ALIGN - 1))); \ + \ + memcpy(dest_buf, (void const *)__funcp_address, size); \ + flush_icache_range((unsigned long)(dest_buf), \ + (unsigned long)(dest_buf) + (size)); \ + \ + asm("" : "=r" (__result) \ + : "0" ((uintptr_t)(dest_buf))); \ + \ + __result; \ +}) + +#endif /* !__ASM_ARM_FNCPY_H */