Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757770Ab3FLBaQ (ORCPT ); Tue, 11 Jun 2013 21:30:16 -0400 Received: from smtp.codeaurora.org ([198.145.11.231]:59206 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757753Ab3FLBaN (ORCPT ); Tue, 11 Jun 2013 21:30:13 -0400 From: Stephen Boyd To: Russell King Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Rob Herring , Stephen Warren Subject: [PATCH] ARM: mmu: Add debug_ll_io_init() mappings to early mappings Date: Tue, 11 Jun 2013 18:30:07 -0700 Message-Id: <1371000607-1787-1-git-send-email-sboyd@codeaurora.org> X-Mailer: git-send-email 1.8.3.251.g1462b67 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4442 Lines: 98 Failure to add the mapping created in debug_ll_io_init() can lead to the BUG_ON() triggering in lib/ioremap.c:27 if the static virtual address decided for the debug_ll mapping overlaps with another mapping that is created later. This happens because the generic ioremap code has no idea there is a mapping there and it tries to place a mapping in the same location and blows up when it sees that there is a pte already present. kernel BUG at lib/ioremap.c:27! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.10.0-rc2-00042-g2af0c67-dirty #316 task: ef088000 ti: ef082000 task.ti: ef082000 PC is at ioremap_page_range+0x16c/0x198 LR is at ioremap_page_range+0xf0/0x198 pc : [] lr : [] psr: 20000113 sp : ef083e78 ip : af140000 fp : ef083ebc r10: ef7fc100 r9 : ef7fc104 r8 : 000af174 r7 : 00000647 r6 : beffffff r5 : f004c000 r4 : f0040000 r3 : af173417 r2 : 16440653 r1 : af173e07 r0 : ef7fc8fc Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c5787d Table: 8020406a DAC: 00000015 Process swapper/0 (pid: 1, stack limit = 0xef082238) Stack: (0xef083e78 to 0xef084000) 3e60: 00040000 ef083eec 3e80: bf134000 f004bfff c0207c00 f004c000 c02fc120 f000c000 c15e7800 00040000 3ea0: ef083eec 00000647 c098ba9c c0953544 ef083edc ef083ec0 c021b82c c04cb714 3ec0: c09cdc50 00000040 ef0f1e00 ef1003c0 ef083f14 ef083ee0 c09535bc c021b7bc 3ee0: c0953544 c04d0c6c c094e2cc c1600be4 c07440c4 c09a6888 00000002 c0a15f00 3f00: ef082000 00000000 ef083f54 ef083f18 c0208728 c0953550 00000002 c1600bfc 3f20: c08e3fac c0839918 ef083f54 c1600b80 c09a6888 c0a15f00 0000008b c094e2cc 3f40: c098ba9c c098bab8 ef083f94 ef083f58 c094ea0c c020865c 00000002 00000002 3f60: c094e2cc 00000000 c025b674 00000000 c06ff860 00000000 00000000 00000000 3f80: 00000000 00000000 ef083fac ef083f98 c06ff878 c094e910 00000000 00000000 3fa0: 00000000 ef083fb0 c020efe8 c06ff86c 00000000 00000000 00000000 00000000 3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 3fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 c0595108 [] (ioremap_page_range+0x16c/0x198) from [] (__alloc_remap_buffer.isra.18+0x7c/0xc4) [] (__alloc_remap_buffer.isra.18+0x7c/0xc4) from [] (atomic_pool_init+0x78/0x128) [] (atomic_pool_init+0x78/0x128) from [] (do_one_initcall+0xd8/0x198) [] (do_one_initcall+0xd8/0x198) from [] (kernel_init_freeable+0x108/0x1d0) [] (kernel_init_freeable+0x108/0x1d0) from [] (kernel_init+0x18/0xf4) [] (kernel_init+0x18/0xf4) from [] (ret_from_fork+0x14/0x20) Code: e50b0040 ebf54b2f e51b0040 eaffffee (e7f001f2) Fix it by telling generic layers about the static mapping. This also has the nice side effect of letting you see the mapping in procfs' vmallocinfo file. Cc: Rob Herring Cc: Stephen Warren Signed-off-by: Stephen Boyd --- arch/arm/mm/mmu.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index e0d8565..04fe160 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -938,8 +938,12 @@ static void __init pci_reserve_io(void) #ifdef CONFIG_DEBUG_LL void __init debug_ll_io_init(void) { + struct vm_struct *vm; + struct static_vm *svm; struct map_desc map; + svm = early_alloc_aligned(sizeof(*svm), __alignof__(*svm)); + debug_ll_addr(&map.pfn, &map.virtual); if (!map.pfn || !map.virtual) return; @@ -948,6 +952,15 @@ void __init debug_ll_io_init(void) map.length = PAGE_SIZE; map.type = MT_DEVICE; create_mapping(&map); + + vm = &svm->vm; + vm->addr = (void *)map.virtual; + vm->size = map.length; + vm->phys_addr = __pfn_to_phys(map.pfn); + vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING; + vm->flags |= VM_ARM_MTYPE(map.type); + vm->caller = debug_ll_io_init; + add_static_vm_early(svm); } #endif -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/