From mboxrd@z Thu Jan 1 00:00:00 1970 From: Taniya Das Subject: arm_memblock_steal() API usage Date: Tue, 03 Apr 2012 09:34:03 +0530 Message-ID: <4F7A76B3.3070405@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from wolverine01.qualcomm.com ([199.106.114.254]:1953 "EHLO wolverine01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750722Ab2DCEEH (ORCPT ); Tue, 3 Apr 2012 00:04:07 -0400 Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: linux-arm-kernel@lists.infradead.org, linux@arm.linux.org.uk Cc: linux-arm-msm@vger.kernel.org, tsoni@codeaurora.org Hi RMK, I have a requirement where I need around ~100 bytes of memory to save contents of registers to a non-cached area before going into low power mode. I did do some analysis on a 1GB RAM device of allocating 8 bytes using the API and the below was the result was showing allocating only 8 bytes. API used : - arm_memblock_steal(SZ_8, SZ_64K);--> physical address returned is 0x3b1f0000 /data/debug/memblock # cat memory 0: 0x00200000..0x3b1effff 1: 0x3b1f0008..0x3b1fffff [0x3b1f0000-0x3b1f0007] only 8 bytes removed. /data/debug/memblock # cat reserved 0: 0x00204000..0x00c710fb 1: 0x01400000..0x01429b44 2: 0x0ffe0000..0x0ffeffff 3: 0x2d9f3000..0x2d9fffff 4: 0x3b1f0008..0x3b1fffff But before I can go ahead and use this if you could confirm that it will allocate only the size requested or it will carve out minimum 1MB? Also is this API advisable for devices with low system RAM? -- Thanks& Regards, Taniya Das. Consultant for Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum