From patchwork Mon Jul 22 11:07:36 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mauro Carvalho Chehab X-Patchwork-Id: 11052153 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A540E13B1 for ; Mon, 22 Jul 2019 11:08:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9504A285C8 for ; Mon, 22 Jul 2019 11:08:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 89AF2285C9; Mon, 22 Jul 2019 11:08:04 +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=-7.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham 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 C8081285CB for ; Mon, 22 Jul 2019 11:08:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729849AbfGVLID (ORCPT ); Mon, 22 Jul 2019 07:08:03 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:35664 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729843AbfGVLIB (ORCPT ); Mon, 22 Jul 2019 07:08:01 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=a+bQj1O+XRjfOgK19pvPFmYDIh6VgLh2sOF6Gxqi2+E=; b=WEV9kenwMJfXXQFoAu1jII0oV3 fZluZEm6iCvyJy0DYk2C/hV7zIFleSaux6waquQdpDY6cPahrcX8kcvTV2uIDkm4B+SaQKHo7CIJH chp8vYXExfijeRlEw1y2evaHoR4apGas/I/ftdr4UWZiKNEs95vHvx5XRzo3AM0BEzP4H3FOyxUCX gofbwRhY8SAfX0PQ6FgJjOBszMUNTldqmq2qcUz6g5LhPI418gpruGzYoTchvZ61z0ehjcj07M/jO myzIKk79IdaZ4UHkE4XT5oKDmQk28goKB3BrnekJaC/mftyQiJQ3NllextFfHHytLDfNDoiY5Aj6V kDhnISNQ==; Received: from 177.157.124.3.dynamic.adsl.gvt.net.br ([177.157.124.3] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1hpWAe-00024w-MN; Mon, 22 Jul 2019 11:07:56 +0000 Received: from mchehab by bombadil.infradead.org with local (Exim 4.92) (envelope-from ) id 1hpWAa-000413-7e; Mon, 22 Jul 2019 08:07:52 -0300 From: Mauro Carvalho Chehab Cc: Mauro Carvalho Chehab , Jonathan Corbet , "James E.J. Bottomley" , Helge Deller , linux-doc@vger.kernel.org, linux-parisc@vger.kernel.org Subject: [PATCH 09/22] docs: parisc: convert to ReST and add to documentation body Date: Mon, 22 Jul 2019 08:07:36 -0300 Message-Id: X-Mailer: git-send-email 2.21.0 In-Reply-To: References: MIME-Version: 1.0 To: unlisted-recipients:; (no To-header on input) Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Manually convert the two PA-RISC documents to ReST, adding them to the Linux documentation body. Signed-off-by: Mauro Carvalho Chehab --- Documentation/index.rst | 1 + .../parisc/{debugging => debugging.rst} | 7 +++ Documentation/parisc/index.rst | 18 ++++++ .../parisc/{registers => registers.rst} | 59 +++++++++++++------ 4 files changed, 68 insertions(+), 17 deletions(-) rename Documentation/parisc/{debugging => debugging.rst} (94%) create mode 100644 Documentation/parisc/index.rst rename Documentation/parisc/{registers => registers.rst} (70%) diff --git a/Documentation/index.rst b/Documentation/index.rst index ef9543c2516d..9bb08d272bd5 100644 --- a/Documentation/index.rst +++ b/Documentation/index.rst @@ -149,6 +149,7 @@ implementation. ia64/index m68k/index powerpc/index + parisc/index riscv/index s390/index sh/index diff --git a/Documentation/parisc/debugging b/Documentation/parisc/debugging.rst similarity index 94% rename from Documentation/parisc/debugging rename to Documentation/parisc/debugging.rst index 7d75223fa18d..de1b60402c5b 100644 --- a/Documentation/parisc/debugging +++ b/Documentation/parisc/debugging.rst @@ -1,8 +1,13 @@ +================= +PA-RISC Debugging +================= + okay, here are some hints for debugging the lower-level parts of linux/parisc. 1. Absolute addresses +===================== A lot of the assembly code currently runs in real mode, which means absolute addresses are used instead of virtual addresses as in the @@ -12,6 +17,7 @@ currently). 2. HPMCs +======== When real-mode code tries to access non-existent memory, you'll get an HPMC instead of a kernel oops. To debug an HPMC, try to find @@ -27,6 +33,7 @@ access it. 3. Q bit fun +============ Certain, very critical code has to clear the Q bit in the PSW. What happens when the Q bit is cleared is the CPU does not update the diff --git a/Documentation/parisc/index.rst b/Documentation/parisc/index.rst new file mode 100644 index 000000000000..aa3ee0470425 --- /dev/null +++ b/Documentation/parisc/index.rst @@ -0,0 +1,18 @@ +.. SPDX-License-Identifier: GPL-2.0 + +==================== +PA-RISC Architecture +==================== + +.. toctree:: + :maxdepth: 2 + + debugging + registers + +.. only:: subproject and html + + Indices + ======= + + * :ref:`genindex` diff --git a/Documentation/parisc/registers b/Documentation/parisc/registers.rst similarity index 70% rename from Documentation/parisc/registers rename to Documentation/parisc/registers.rst index 10c7d1730f5d..59c8ecf3e856 100644 --- a/Documentation/parisc/registers +++ b/Documentation/parisc/registers.rst @@ -1,11 +1,16 @@ +================================ Register Usage for Linux/PA-RISC +================================ [ an asterisk is used for planned usage which is currently unimplemented ] - General Registers as specified by ABI +General Registers as specified by ABI +===================================== - Control Registers +Control Registers +----------------- +=============================== =============================================== CR 0 (Recovery Counter) used for ptrace CR 1-CR 7(undefined) unused CR 8 (Protection ID) per-process value* @@ -29,26 +34,35 @@ CR28 (TR 4) not used CR29 (TR 5) not used CR30 (TR 6) current / 0 CR31 (TR 7) Temporary register, used in various places +=============================== =============================================== - Space Registers (kernel mode) +Space Registers (kernel mode) +----------------------------- +=============================== =============================================== SR0 temporary space register SR4-SR7 set to 0 SR1 temporary space register SR2 kernel should not clobber this SR3 used for userspace accesses (current process) +=============================== =============================================== - Space Registers (user mode) +Space Registers (user mode) +--------------------------- +=============================== =============================================== SR0 temporary space register SR1 temporary space register SR2 holds space of linux gateway page SR3 holds user address space value while in kernel SR4-SR7 Defines short address space for user/kernel +=============================== =============================================== - Processor Status Word +Processor Status Word +--------------------- +=============================== =============================================== W (64-bit addresses) 0 E (Little-endian) 0 S (Secure Interval Timer) 0 @@ -69,15 +83,19 @@ Q (collect interruption state) 1 (0 in code directly preceding an rfi) P (Protection Identifiers) 1* D (Data address translation) 1, 0 while executing real-mode code I (external interrupt mask) used by cli()/sti() macros +=============================== =============================================== - "Invisible" Registers +"Invisible" Registers +--------------------- +=============================== =============================================== PSW default W value 0 PSW default E value 0 Shadow Registers used by interruption handler code TOC enable bit 1 +=============================== =============================================== -========================================================================= +------------------------------------------------------------------------- The PA-RISC architecture defines 7 registers as "shadow registers". Those are used in RETURN FROM INTERRUPTION AND RESTORE instruction to reduce @@ -85,7 +103,8 @@ the state save and restore time by eliminating the need for general register (GR) saves and restores in interruption handlers. Shadow registers are the GRs 1, 8, 9, 16, 17, 24, and 25. -========================================================================= +------------------------------------------------------------------------- + Register usage notes, originally from John Marvin, with some additional notes from Randolph Chung. @@ -96,10 +115,12 @@ course, you need to save them if you care about them, before calling another procedure. Some of the above registers do have special meanings that you should be aware of: - r1: The addil instruction is hardwired to place its result in r1, + r1: + The addil instruction is hardwired to place its result in r1, so if you use that instruction be aware of that. - r2: This is the return pointer. In general you don't want to + r2: + This is the return pointer. In general you don't want to use this, since you need the pointer to get back to your caller. However, it is grouped with this set of registers since the caller can't rely on the value being the same @@ -107,23 +128,27 @@ that you should be aware of: and return through that register after trashing r2, and that should not cause a problem for the calling routine. - r19-r22: these are generally regarded as temporary registers. + r19-r22: + these are generally regarded as temporary registers. Note that in 64 bit they are arg7-arg4. - r23-r26: these are arg3-arg0, i.e. you can use them if you + r23-r26: + these are arg3-arg0, i.e. you can use them if you don't care about the values that were passed in anymore. - r28,r29: are ret0 and ret1. They are what you pass return values + r28,r29: + are ret0 and ret1. They are what you pass return values in. r28 is the primary return. When returning small structures r29 may also be used to pass data back to the caller. - r30: stack pointer + r30: + stack pointer - r31: the ble instruction puts the return pointer in here. + r31: + the ble instruction puts the return pointer in here. -r3-r18,r27,r30 need to be saved and restored. r3-r18 are just + r3-r18,r27,r30 need to be saved and restored. r3-r18 are just general purpose registers. r27 is the data pointer, and is used to make references to global variables easier. r30 is the stack pointer. -