From patchwork Mon Oct 22 17:42:54 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stephen Warren X-Patchwork-Id: 1627441 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id AD0ABDFB79 for ; Mon, 22 Oct 2012 17:45:04 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TQM1u-0004p2-Kk; Mon, 22 Oct 2012 17:43:10 +0000 Received: from avon.wwwdotorg.org ([2001:470:1f0f:bd7::2]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1TQM1r-0004oj-Ep for linux-arm-kernel@lists.infradead.org; Mon, 22 Oct 2012 17:43:08 +0000 Received: from severn.wwwdotorg.org (unknown [192.168.65.5]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by avon.wwwdotorg.org (Postfix) with ESMTPS id 55FFD622D; Mon, 22 Oct 2012 11:43:03 -0600 (MDT) Received: from localhost.localdomain (localhost [127.0.0.1]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by severn.wwwdotorg.org (Postfix) with ESMTPSA id 125D9E4622; Mon, 22 Oct 2012 11:42:58 -0600 (MDT) From: Stephen Warren To: arm@kernel.org Subject: [PATCH V4] ARM: implement debug_ll_io_init() Date: Mon, 22 Oct 2012 11:42:54 -0600 Message-Id: <1350927774-14020-1-git-send-email-swarren@wwwdotorg.org> X-Mailer: git-send-email 1.7.0.4 X-NVConfidentiality: public X-Virus-Scanned: clamav-milter 0.96.5 at avon.wwwdotorg.org X-Virus-Status: Clean X-Spam-Note: CRM114 invocation failed X-Spam-Score: -2.2 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record -0.7 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] 0.4 DECEASED_NO_ML Dead not via mailing list Cc: Russell King - ARM Linux , Arnd Bergmann , Rob Herring , linux-tegra@vger.kernel.org, Olof Johansson , Stephen Warren , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org From: Rob Herring When using DEBUG_LL, the UART's (or other HW's) registers are mapped into early page tables based on the results of assembly macro addruart. Later, when the page tables are replaced, the same virtual address must remain valid. Historically, this has been ensured by using defines from in both the implementation of addruart, and the machine's .map_io() function. However, with the move to single zImage, we wish to remove . To enable this, the macro addruart may be used when constructing the late page tables too; addruart is exposed as a C function debug_ll_addr(), and used to set up the required mapping in debug_ll_io_init(), which may called on an opt-in basis from a machine's .map_io() function. Signed-off-by: Rob Herring [swarren: Mask map.virtual with PAGE_MASK. Checked for NULL results from debug_ll_addr (e.g. when selected UART isn't valid). Fixed compile when either !CONFIG_DEBUG_LL or CONFIG_DEBUG_SEMIHOSTING.] Signed-off-by: Stephen Warren --- This patch is a dependency for the Tegra debug-macro.S rework. I assume it should go into some arm-soc branch so that if others want to take advantage of it this kernel cycle, they can. v4: Fix DEBUG_SEMIHOSTING's debug_ll_addr to actually fill in the "out" parameters. v3: New patch. --- arch/arm/include/asm/mach/map.h | 7 +++++++ arch/arm/kernel/debug.S | 14 ++++++++++++++ arch/arm/mm/mmu.c | 16 ++++++++++++++++ 3 files changed, 37 insertions(+), 0 deletions(-) diff --git a/arch/arm/include/asm/mach/map.h b/arch/arm/include/asm/mach/map.h index 195ac2f..2fe141f 100644 --- a/arch/arm/include/asm/mach/map.h +++ b/arch/arm/include/asm/mach/map.h @@ -40,6 +40,13 @@ extern void iotable_init(struct map_desc *, int); extern void vm_reserve_area_early(unsigned long addr, unsigned long size, void *caller); +#ifdef CONFIG_DEBUG_LL +extern void debug_ll_addr(unsigned long *paddr, unsigned long *vaddr); +extern void debug_ll_io_init(void); +#else +static inline void debug_ll_io_init(void) {} +#endif + struct mem_type; extern const struct mem_type *get_mem_type(unsigned int type); /* diff --git a/arch/arm/kernel/debug.S b/arch/arm/kernel/debug.S index 66f711b..6809200 100644 --- a/arch/arm/kernel/debug.S +++ b/arch/arm/kernel/debug.S @@ -100,6 +100,13 @@ ENTRY(printch) b 1b ENDPROC(printch) +ENTRY(debug_ll_addr) + addruart r2, r3, ip + str r2, [r0] + str r3, [r1] + mov pc, lr +ENDPROC(debug_ll_addr) + #else ENTRY(printascii) @@ -119,4 +126,11 @@ ENTRY(printch) mov pc, lr ENDPROC(printch) +ENTRY(debug_ll_addr) + mov r2, #0 + str r2, [r0] + str r2, [r1] + mov pc, lr +ENDPROC(debug_ll_addr) + #endif diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 941dfb9..39719bb 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -876,6 +876,22 @@ static void __init pci_reserve_io(void) #define pci_reserve_io() do { } while (0) #endif +#ifdef CONFIG_DEBUG_LL +void __init debug_ll_io_init(void) +{ + struct map_desc map; + + debug_ll_addr(&map.pfn, &map.virtual); + if (!map.pfn || !map.virtual) + return; + map.pfn = __phys_to_pfn(map.pfn); + map.virtual &= PAGE_MASK; + map.length = PAGE_SIZE; + map.type = MT_DEVICE; + create_mapping(&map); +} +#endif + static void * __initdata vmalloc_min = (void *)(VMALLOC_END - (240 << 20) - VMALLOC_OFFSET);