From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751310AbaHIFpm (ORCPT ); Sat, 9 Aug 2014 01:45:42 -0400 Received: from e23smtp05.au.ibm.com ([202.81.31.147]:36531 "EHLO e23smtp05.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750949AbaHIFpk (ORCPT ); Sat, 9 Aug 2014 01:45:40 -0400 Subject: [PATCH v3 1/2] printk: Add function to return log buffer address and size To: linuxppc-dev@lists.ozlabs.org From: Vasant Hegde Cc: Benjamin Herrenschmidt , Andrew Morton , Linus Torvalds , linux-kernel@vger.kernel.org Date: Sat, 09 Aug 2014 11:15:30 +0530 Message-ID: <20140809054424.17676.1090.stgit@hegdevasant.in.ibm.com> User-Agent: StGit/0.16 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14080905-1396-0000-0000-0000000D9A5E Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Platforms like IBM Power Systems supports service processor assisted dump. It provides interface to add memory region to be captured when system is crashed. During initialization/running we can add kernel memory region to be collected. Presently we don't have a way to get the log buffer base address and size. This patch adds support to return log buffer address and size. Signed-off-by: Vasant Hegde Signed-off-by: Benjamin Herrenschmidt --- Next patch extends arch specific code to add log buffer to platform dump. Changes in v3: As Andrew suggested changed function names and return type. (https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-August/119802.html). Ben, - This patchset applies cleanly on powerpc next branch. - Andrew Morton suggested to include this patch in powerpc tree. (https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-August/119802.html) include/linux/printk.h | 3 +++ kernel/printk/printk.c | 12 ++++++++++++ 2 files changed, 15 insertions(+) diff --git a/include/linux/printk.h b/include/linux/printk.h index 319ff7e..b8c0316 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -10,6 +10,9 @@ extern const char linux_banner[]; extern const char linux_proc_banner[]; +extern char *log_buf_addr_get(void); +extern u32 log_buf_len_get(void); + static inline int printk_get_level(const char *buffer) { if (buffer[0] == KERN_SOH_ASCII && buffer[1]) { diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index ea2d5f6..d6a984c 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -270,6 +270,18 @@ static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN); static char *log_buf = __log_buf; static u32 log_buf_len = __LOG_BUF_LEN; +/* Return log buffer address */ +char *log_buf_addr_get(void) +{ + return log_buf; +} + +/* Return log buffer size */ +u32 log_buf_len_get(void) +{ + return log_buf_len; +} + /* human readable text of the record */ static char *log_text(const struct printk_log *msg) {