From patchwork Fri May 5 19:47:32 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 98700 Delivered-To: patch@linaro.org Received: by 10.140.96.100 with SMTP id j91csp292901qge; Fri, 5 May 2017 12:48:49 -0700 (PDT) X-Received: by 10.98.204.87 with SMTP id a84mr15407502pfg.6.1494013729763; Fri, 05 May 2017 12:48:49 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id n5si2698005pgk.367.2017.05.05.12.48.49; Fri, 05 May 2017 12:48:49 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755858AbdEETss (ORCPT + 6 others); Fri, 5 May 2017 15:48:48 -0400 Received: from mout.kundenserver.de ([212.227.126.130]:64319 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755673AbdEETsh (ORCPT ); Fri, 5 May 2017 15:48:37 -0400 Received: from wuerfel.lan ([78.42.17.5]) by mrelayeu.kundenserver.de (mreue002 [212.227.15.129]) with ESMTPA (Nemesis) id 0MR7U6-1dULS01qNK-00UJF5; Fri, 05 May 2017 21:48:34 +0200 From: Arnd Bergmann To: Ben Hutchings Cc: stable@vger.kernel.org, Stefan Agner , Russell King , Arnd Bergmann , Greg Kroah-Hartman Subject: [PATCH 3.16-stable 74/87] ARM: 8383/1: nommu: avoid deprecated source register on mov Date: Fri, 5 May 2017 21:47:32 +0200 Message-Id: <20170505194745.3627137-75-arnd@arndb.de> X-Mailer: git-send-email 2.9.0 In-Reply-To: <20170505194745.3627137-1-arnd@arndb.de> References: <20170505194745.3627137-1-arnd@arndb.de> X-Provags-ID: V03:K0:DJKJVUSH71nx341X21WquTlsU2pGPTH4sYm7c974MLPhbQ0+xHq dyybZbgPdS1j0sHEu6tphtij54S/xKWtwOH6H/EeMkyKrX5aNgKR18wyK1dvnJ+ZCIcGYhD aqwcf8RSpBU1nWXhfIPYibTsNFHk72zagn05UW8uvtbeQ32UtVHDQt4qJl5+D2awzSKN0NB /VrcDX4/ttIFgYxYLKBcA== X-UI-Out-Filterresults: notjunk:1; V01:K0:rS6+G1225ww=:/HC6NMkgSxWoORJxvRlUpY lhnGoIckQZ24dGacRJfiiPczuf079SNU7IUcuZM/8OzQyiaCuvnmi6e0zMxNWJnijuOI2fHQ7 NCWfuAd4LHK+1yh/FtCwJQUBn8erq1H//mlsNPkOF9IJvIS+zKMXReDMNCApI6mfAuDBjTLy8 OOWuDdWZEJgJfT+m5tLY/ZH+UR8ba5panLBM9Y8Y8dfJqmZLP3o1lQ8oFKtUfrEFesAzZSvPd 1K329aaT8aaSe4SqidLYZ/9giy1a4iRh3TR04zyyPvtbOtXKiflfQ1SZYZieNpF7OW184EWqI BFkERzKZUYtJ8fTT4jFhHAN046qQn9PynR2hGQAlixH/e8D76Aklis8RZzrq2lY7jIBXzZ58a MIaNeULa2ek/QNtVf2TCJ7MbcG9Q6bNYDE0pXxAocfODT16Vl/ERM5C4oRK2w2viuHLVJZciF czyA/80/lDT4F0rcoOKZklrLTyIO7oidF/zBUTKnSVRqjQ9yyYk1H56wu0ET15/z0Jj2G+AlT JPcrXRBIsu/mrBxba0FgCBizDGRjDnn22QcFGXPEmiM9tbEVbhLbcnS2qPz0mDPTUU2cuNcJO MaDDdt/sEQWdIUH96Zfvh5PTp730E20FX/rw302XNZL/wtYQyyjxOPSpu7J4GKCDTzCn3TsfW 6DTpoqhOz/QfDTy3XaesA0gfJLFR1zbH8AxrYjNZnvBBq6PZutZBBy6pEchCr/uTqJfo= Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Stefan Agner commit 970d96f9a81b0dd83ddd8bce0e5e1ba31881c5f5 upstream. In Thumb2 mode, the stack register r13 is deprecated if the destination register is the program counter (r15). Similar to head.S, head-nommu.S uses r13 to store the return address used after configuring the CPU's CP15 register. However, since we do not enable a MMU, there will be no address switch and it is possible to use branch with link instruction to call __after_proc_init. Avoid using r13 completely by using bl to call __after_proc_init and get rid of __secondary_switched. Beside removing unnecessary complexity, this also fixes a compiler warning when compiling a !MMU kernel: Warning: Use of r13 as a source register is deprecated when r15 is the destination register. Tested-by: Maxime Coquelin Signed-off-by: Stefan Agner Signed-off-by: Russell King Signed-off-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman Signed-off-by: Arnd Bergmann --- arch/arm/kernel/head-nommu.S | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) -- 2.9.0 diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S index 716249cc2ee1..db0c82f4a99b 100644 --- a/arch/arm/kernel/head-nommu.S +++ b/arch/arm/kernel/head-nommu.S @@ -77,13 +77,12 @@ ENTRY(stext) orr r6, r6, #(1 << MPU_RSR_EN) @ Set region enabled bit bl __setup_mpu #endif - ldr r13, =__mmap_switched @ address to jump to after - @ initialising sctlr adr lr, BSYM(1f) @ return (PIC) address ARM( add pc, r10, #PROCINFO_INITFUNC ) THUMB( add r12, r10, #PROCINFO_INITFUNC ) THUMB( mov pc, r12 ) - 1: b __after_proc_init +1: bl __after_proc_init + b __mmap_switched ENDPROC(stext) #ifdef CONFIG_SMP @@ -106,8 +105,7 @@ ENTRY(secondary_startup) movs r10, r5 @ invalid processor? beq __error_p @ yes, error 'p' - adr r4, __secondary_data - ldmia r4, {r7, r12} + ldr r7, __secondary_data #ifdef CONFIG_ARM_MPU /* Use MPU region info supplied by __cpu_up */ @@ -115,23 +113,19 @@ ENTRY(secondary_startup) bl __setup_mpu @ Initialize the MPU #endif - adr lr, BSYM(__after_proc_init) @ return address - mov r13, r12 @ __secondary_switched address + adr lr, BSYM(1f) @ return (PIC) address ARM( add pc, r10, #PROCINFO_INITFUNC ) THUMB( add r12, r10, #PROCINFO_INITFUNC ) THUMB( mov pc, r12 ) -ENDPROC(secondary_startup) - -ENTRY(__secondary_switched) +1: bl __after_proc_init ldr sp, [r7, #8] @ set up the stack pointer mov fp, #0 b secondary_start_kernel -ENDPROC(__secondary_switched) +ENDPROC(secondary_startup) .type __secondary_data, %object __secondary_data: .long secondary_data - .long __secondary_switched #endif /* CONFIG_SMP */ /* @@ -164,7 +158,11 @@ __after_proc_init: #endif mcr p15, 0, r0, c1, c0, 0 @ write control reg #endif /* CONFIG_CPU_CP15 */ +<<<<<<< HEAD mov pc, r13 +======= + ret lr +>>>>>>> 12ebe5ca67dc... ARM: 8383/1: nommu: avoid deprecated source register on mov ENDPROC(__after_proc_init) .ltorg