Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756205AbXJIUkz (ORCPT ); Tue, 9 Oct 2007 16:40:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753593AbXJIUkr (ORCPT ); Tue, 9 Oct 2007 16:40:47 -0400 Received: from E23SMTP04.au.ibm.com ([202.81.18.173]:41848 "EHLO e23smtp04.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752939AbXJIUkq (ORCPT ); Tue, 9 Oct 2007 16:40:46 -0400 Subject: [RFC] [Patch] calgary iommu: Use the first kernel's tce tables in kdump From: chandru To: linux-kernel@vger.kernel.org Cc: mark_salyzyn@adaptec.com, muli@il.ibm.com, ak@suse.de, vgoyal@in.ibm.com Content-Type: text/plain Date: Wed, 10 Oct 2007 02:10:13 +0530 Message-Id: <1191962414.24134.68.camel@chandru> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6217 Lines: 174 kdump kernel fails to boot with calgary iommu and aacraid driver on a x366 box. The ongoing dma's of aacraid from the first kernel continue to exist until the driver is loaded in the kdump kernel. Calgary is initialized prior to aacraid and creation of new tce tables causes wrong dma's to occur. Here we try to grab the tce tables of the first kernel in kdump kernel and use them. While in the kdump kernel we do not allocate new tce tables but rather read the base address register contents of calgary iommu and use the tables that the registers point to. With these changes the kdump kernel and hence aacraid now boots normally. Another point that came when talking with Vivek was to reserve part of the tce table space in first kernel for use in the kdump kernel. Signed-off-by: Chandru S --- --- linux-2.6.23-rc9/arch/x86_64/kernel/pci-calgary.c.orig 2007-10-09 23:39:22.000000000 +0530 +++ linux-2.6.23-rc9/arch/x86_64/kernel/pci-calgary.c 2007-10-10 01:25:53.000000000 +0530 @@ -35,6 +35,7 @@ #include #include #include +#include #include #include #include @@ -165,6 +166,7 @@ static void calgary_dump_error_regs(stru static void calioc2_handle_quirks(struct iommu_table *tbl, struct pci_dev *dev); static void calioc2_tce_cache_blast(struct iommu_table *tbl); static void calioc2_dump_error_regs(struct iommu_table *tbl); +static int calgary_bus_has_devices(int , unsigned short ) __init; static struct cal_chipset_ops calgary_chip_ops = { .handle_quirks = calgary_handle_quirks, @@ -819,7 +821,23 @@ static int __init calgary_setup_tar(stru tbl = pci_iommu(dev->bus); tbl->it_base = (unsigned long)bus_info[dev->bus->number].tce_space; - tce_free(tbl, 0, tbl->it_size); +#ifdef CONFIG_CRASH_DUMP + if (is_kdump_kernel()){ + u64 *tp; + unsigned int index; + tp = ((u64*)tbl->it_base); + for(index=0;index < tbl->it_size; index++ ){ + if ( *tp != 0x0 ) + set_bit(index,tbl->it_map); + + tp++; + } + } + else +#endif + { + tce_free(tbl, 0, tbl->it_size); + } if (is_calgary(dev->device)) tbl->chip_ops = &calgary_chip_ops; @@ -1177,6 +1195,43 @@ static int __init calgary_locate_bbars(v } } +#ifdef CONFIG_CRASH_DUMP + /* + * If this is a kdump kernel, then try grabbing the tce tables + * from first kernel by reading the contents of the base + * address register of calgary iommu + */ + if(is_kdump_kernel()){ + for (bus = 0; bus < MAX_PHB_BUS_NUM; bus++) { + struct calgary_bus_info *info = &bus_info[bus]; + unsigned short pci_device; + unsigned long tce_space; + u32 val; + + val = read_pci_config(bus, 0, 0, 0); + pci_device = (val & 0xFFFF0000) >> 16; + + if (!is_cal_pci_dev(pci_device)) + continue; + + if (info->translation_disabled) + continue; + + if (calgary_bus_has_devices(bus, pci_device) || + translate_empty_slots ){ + + target = calgary_reg(bus_info[bus].bbar, tar_offset(bus)); + tce_space = be64_to_cpu(readq(target)); + tce_space = tce_space & TAR_SW_BITS; + + BUG_ON(specified_table_size > TCE_TABLE_SIZE_8M); + + tce_space = tce_space & ( ~specified_table_size); + info->tce_space = (u64 *)__va(tce_space); + } + } + } +#endif return 0; error: @@ -1380,7 +1435,10 @@ void __init detect_calgary(void) return; } - specified_table_size = determine_tce_table_size(end_pfn * PAGE_SIZE); + if(is_kdump_kernel()) + specified_table_size = determine_tce_table_size(saved_max_pfn * PAGE_SIZE); + else + specified_table_size = determine_tce_table_size(end_pfn * PAGE_SIZE); for (bus = 0; bus < MAX_PHB_BUS_NUM; bus++) { struct calgary_bus_info *info = &bus_info[bus]; @@ -1398,10 +1456,17 @@ void __init detect_calgary(void) if (calgary_bus_has_devices(bus, pci_device) || translate_empty_slots) { - tbl = alloc_tce_table(); - if (!tbl) - goto cleanup; - info->tce_space = tbl; + /* + * If this is the kdump kernel then do not allocate + * new tce tables, try using the tce tables from the + * first kernel + */ + if(!is_kdump_kernel()){ + tbl = alloc_tce_table(); + if (!tbl) + goto cleanup; + info->tce_space = tbl; + } calgary_found = 1; } } --- linux-2.6.23-rc9/include/linux/bootmem.h.orig 2007-10-09 23:39:32.000000000 +0530 +++ linux-2.6.23-rc9/include/linux/bootmem.h 2007-10-09 23:26:19.000000000 +0530 @@ -21,6 +21,12 @@ extern unsigned long max_pfn; #ifdef CONFIG_CRASH_DUMP extern unsigned long saved_max_pfn; +static inline int is_kdump_kernel(void) +{ + return reset_devices ? 1 : 0 ; +} +#else +static inline is_kdump_kernel(void) { return 0; } #endif /* - 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/