From patchwork Thu Aug 29 15:50:21 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Maxiwell S. Garcia" X-Patchwork-Id: 1155341 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=kvm-ppc-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 46K6Xs30njz9sPT for ; Fri, 30 Aug 2019 01:51:25 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728640AbfH2PvU (ORCPT ); Thu, 29 Aug 2019 11:51:20 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:17908 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728605AbfH2PvK (ORCPT ); Thu, 29 Aug 2019 11:51:10 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x7TFlssW044910; Thu, 29 Aug 2019 11:51:06 -0400 Received: from ppma04wdc.us.ibm.com (1a.90.2fa9.ip4.static.sl-reverse.com [169.47.144.26]) by mx0a-001b2d01.pphosted.com with ESMTP id 2upfu0n5nw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 29 Aug 2019 11:51:06 -0400 Received: from pps.filterd (ppma04wdc.us.ibm.com [127.0.0.1]) by ppma04wdc.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id x7TFp3O1012114; Thu, 29 Aug 2019 15:51:05 GMT Received: from b01cxnp23034.gho.pok.ibm.com (b01cxnp23034.gho.pok.ibm.com [9.57.198.29]) by ppma04wdc.us.ibm.com with ESMTP id 2ujvv6w8kn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 29 Aug 2019 15:51:05 +0000 Received: from b01ledav005.gho.pok.ibm.com (b01ledav005.gho.pok.ibm.com [9.57.199.110]) by b01cxnp23034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x7TFp4bA18940378 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 29 Aug 2019 15:51:04 GMT Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8D8E6AE060; Thu, 29 Aug 2019 15:51:04 +0000 (GMT) Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 91758AE05F; Thu, 29 Aug 2019 15:51:01 +0000 (GMT) Received: from maxibm.ibmuc.com (unknown [9.85.151.248]) by b01ledav005.gho.pok.ibm.com (Postfix) with ESMTP; Thu, 29 Aug 2019 15:51:01 +0000 (GMT) From: "Maxiwell S. Garcia" To: linuxppc-dev@ozlabs.org Cc: kvm-ppc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, paulus@ozlabs.org, mpe@ellerman.id.au, andmike@linux.ibm.com, linuxram@us.ibm.com, bauerman@linux.ibm.com, cclaudio@linux.ibm.com, "Maxiwell S. Garcia" Subject: [PATCH v2 2/2] docs: powerpc: Add ELF note documentation Date: Thu, 29 Aug 2019 12:50:21 -0300 Message-Id: <20190829155021.2915-3-maxiwell@linux.ibm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190829155021.2915-1-maxiwell@linux.ibm.com> References: <20190829155021.2915-1-maxiwell@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-08-29_07:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=925 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1908290168 Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org The ELF note documentation describes the types and descriptors to be used with the PowerPC namespace. Signed-off-by: Maxiwell S. Garcia Signed-off-by: Claudio Carvalho --- Documentation/powerpc/elfnote.rst | 42 +++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 Documentation/powerpc/elfnote.rst diff --git a/Documentation/powerpc/elfnote.rst b/Documentation/powerpc/elfnote.rst new file mode 100644 index 000000000000..2a5c4beeb809 --- /dev/null +++ b/Documentation/powerpc/elfnote.rst @@ -0,0 +1,42 @@ +========================== +ELF Note PowerPC Namespace +========================== + +The PowerPC namespace in an ELF Note of the kernel binary is used to store +capabilities and information which can be used by a bootloader or userland. + +Types and Descriptors +--------------------- + +The types to be used with the "PowerPC" namesapce are defined in the +include/uapi/asm/elfnote.h + + 1) PPC_ELFNOTE_CAPABILITIES + +Define the capabilities supported/required by the kernel. This type uses a +bitmap as "descriptor" field. Each bit is described below: + +- Ultravisor-capable bit (PowerNV only). + + #define PPCCAP_ULTRAVISOR_BIT (1 << 0) + + Indicate that the powerpc kernel binary knows how to run in an + ultravisor-enabled system. + + In an ultravisor-enabled system, some machine resources are now controlled + by the ultravisor. If the kernel is not ultravisor-capable, but it ends up + being run on a machine with ultravisor, the kernel will probably crash + trying to access ultravisor resources. For instance, it may crash in early + boot trying to set the partition table entry 0. + + In an ultravisor-enabled system, a bootloader could warn the user or prevent + the kernel from being run if the PowerPC ultravisor capability doesn't exist + or the Ultravisor-capable bit is not set. + +References +---------- + +arch/powerpc/include/asm/elfnote.h +arch/powerpc/kernel/note.S + +