From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764694AbcINUHZ (ORCPT ); Wed, 14 Sep 2016 16:07:25 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:43976 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756664AbcINUHI (ORCPT ); Wed, 14 Sep 2016 16:07:08 -0400 X-IMSS-HAND-OFF-DIRECTIVE: 127.0.0.1:10026 From: Reza Arbab To: Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Rob Herring , Frank Rowand , Jonathan Corbet , Andrew Morton Cc: Bharata B Rao , Nathan Fontenot , Stewart Smith , Alistair Popple , Balbir Singh , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, devicetree@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v2 1/3] drivers/of: recognize status property of dt memory nodes Date: Wed, 14 Sep 2016 15:06:56 -0500 X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1473883618-14998-1-git-send-email-arbab@linux.vnet.ibm.com> References: <1473883618-14998-1-git-send-email-arbab@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16091420-0004-0000-0000-00001062238E X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00005761; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000185; SDB=6.00757694; UDB=6.00359416; IPR=6.00531225; BA=6.00004727; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00012673; XFM=3.00000011; UTC=2016-09-14 20:07:06 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16091420-0005-0000-0000-000078E481D4 Message-Id: <1473883618-14998-2-git-send-email-arbab@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-09-14_09:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1609020000 definitions=main-1609140268 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Respect the standard dt "status" property when scanning memory nodes in early_init_dt_scan_memory(), so that if the property is present and not "okay", no memory will be added. The use case at hand is accelerator or device memory, which may be unusable until post-boot initialization of the memory link. Such a node can be described in the dt as any other, given its status is "disabled". Per the device tree specification, "disabled" Indicates that the device is not presently operational, but it might become operational in the future (for example, something is not plugged in, or switched off). Once such memory is made operational, it can then be hotplugged. Signed-off-by: Reza Arbab --- drivers/of/fdt.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 085c638..fc19590 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -1022,8 +1022,10 @@ int __init early_init_dt_scan_memory(unsigned long node, const char *uname, int depth, void *data) { const char *type = of_get_flat_dt_prop(node, "device_type", NULL); + const char *status; const __be32 *reg, *endp; int l; + bool add_memory; /* We are scanning "memory" nodes only */ if (type == NULL) { @@ -1044,6 +1046,9 @@ int __init early_init_dt_scan_memory(unsigned long node, const char *uname, endp = reg + (l / sizeof(__be32)); + status = of_get_flat_dt_prop(node, "status", NULL); + add_memory = !status || !strcmp(status, "okay"); + pr_debug("memory scan node %s, reg size %d,\n", uname, l); while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) { @@ -1057,6 +1062,9 @@ int __init early_init_dt_scan_memory(unsigned long node, const char *uname, pr_debug(" - %llx , %llx\n", (unsigned long long)base, (unsigned long long)size); + if (!add_memory) + continue; + early_init_dt_add_memory_arch(base, size); } -- 1.8.3.1