Mikael Pettersson writes: > The combination of HIGHMEM64G and PCI doesn't work in 2.6.31-rc1, > causing a hang in PCI initialisation during boot: > > Linux version 2.6.31-rc1 (mikpe@brewer) (gcc version 4.3.4 20090621 (prerelease) (GCC) ) #1 Fri Jun 26 16:01:50 CEST 2009 > KERNEL supported cpus: > Intel GenuineIntel > BIOS-provided physical RAM map: > BIOS-e820: 0000000000000000 - 000000000009ec00 (usable) > BIOS-e820: 000000000009ec00 - 00000000000a0000 (reserved) > BIOS-e820: 00000000000e4000 - 0000000000100000 (reserved) > BIOS-e820: 0000000000100000 - 000000007ff90000 (usable) > BIOS-e820: 000000007ff90000 - 000000007ff9e000 (ACPI data) > BIOS-e820: 000000007ff9e000 - 000000007ffe0000 (ACPI NVS) > BIOS-e820: 000000007ffe0000 - 0000000080000000 (reserved) > BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved) > BIOS-e820: 00000000ffb00000 - 0000000100000000 (reserved) > BIOS-e820: 0000000100000000 - 0000000200000000 (usable) > DMI 2.4 present. > last_pfn = 0x200000 max_arch_pfn = 0x1000000 > init_memory_mapping: 0000000000000000-00000000379fe000 > NX (Execute Disable) protection: active > RAMDISK: 37ebb000 - 37fef7c6 > Allocated new RAMDISK: 00221000 - 003557c6 > Move RAMDISK from 0000000037ebb000 - 0000000037fef7c5 to 00221000 - 003557c5 > 7302MB HIGHMEM available. > 889MB LOWMEM available. > mapped low ram: 0 - 379fe000 > low ram: 0 - 379fe000 > node 0 low ram: 00000000 - 379fe000 > node 0 bootmap 00009000 - 0000ff40 > (7 early reservations) ==> bootmem [0000000000 - 00379fe000] > #0 [0000000000 - 0000001000] BIOS data page ==> [0000000000 - 0000001000] > #1 [0000100000 - 000021cf18] TEXT DATA BSS ==> [0000100000 - 000021cf18] > #2 [000009ec00 - 0000100000] BIOS reserved ==> [000009ec00 - 0000100000] > #3 [000021d000 - 000022022c] BRK ==> [000021d000 - 000022022c] > #4 [0000007000 - 0000009000] PGTABLE ==> [0000007000 - 0000009000] > #5 [0000221000 - 00003557c6] NEW RAMDISK ==> [0000221000 - 00003557c6] > #6 [0000009000 - 0000010000] BOOTMAP ==> [0000009000 - 0000010000] > Zone PFN ranges: > DMA 0x00000000 -> 0x00001000 > Normal 0x00001000 -> 0x000379fe > HighMem 0x000379fe -> 0x00200000 > Movable zone start PFN for each node > early_node_map[3] active PFN ranges > 0: 0x00000000 -> 0x0000009e > 0: 0x00000100 -> 0x0007ff90 > 0: 0x00100000 -> 0x00200000 > Allocating PCI resources starting at 80000000 (gap: 80000000:7ee00000) > Built 1 zonelists in Zone order, mobility grouping on. Total pages: 1556269 > Kernel command line: ro root=LABEL=32/ console=ttyS0,115200 > PID hash table entries: 4096 (order: 12, 16384 bytes) > Dentry cache hash table entries: 131072 (order: 7, 524288 bytes) > Inode-cache hash table entries: 65536 (order: 6, 262144 bytes) > Enabling fast FPU save and restore... done. > Enabling unmasked SIMD FPU exception support... done. > Initializing CPU#0 > Initializing HighMem for node 0 (000379fe:00200000) > Memory: 6220996k/8388608k available (691k kernel code, 68768k reserved, 203k data, 144k init, 5379656k highmem) > virtual kernel memory layout: > fixmap : 0xfffe6000 - 0xfffff000 ( 100 kB) > pkmap : 0xffa00000 - 0xffc00000 (2048 kB) > vmalloc : 0xf81fe000 - 0xff9fe000 ( 120 MB) > lowmem : 0xc0000000 - 0xf79fe000 ( 889 MB) > .init : 0xc01e2000 - 0xc0206000 ( 144 kB) > .data : 0xc01acd86 - 0xc01dfbdc ( 203 kB) > .text : 0xc0100000 - 0xc01acd86 ( 691 kB) > Checking if this processor honours the WP bit even in supervisor mode...Ok. > NR_IRQS:16 > Fast TSC calibration using PIT > Detected 2400.277 MHz processor. > Console: colour VGA+ 80x25 > console [ttyS0] enabled > Calibrating delay loop (skipped), value calculated using timer frequency.. 4800.55 BogoMIPS (lpj=24002770) > Mount-cache hash table entries: 512 > CPU: L1 I cache: 32K, L1 D cache: 32K > CPU: L2 cache: 4096K > using mwait in idle threads. > CPU: Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz stepping 06 > Checking 'hlt' instruction... OK. > PCI: PCI BIOS revision 3.00 entry at 0xf0031, last bus=2 > PCI: Using configuration type 1 for base access > PCI: Probing PCI hardware > pci 0000:00:01.0: PME# supported from D0 D3hot D3cold > pci 0000:00:01.0: PME# disabled > pci 0000:00:1a.7: PME# supported from D0 D3hot D3cold > pci 0000:00:1a.7: PME# disabled > pci 0000:00:1b.0: PME# supported from D0 D3hot D3cold > pci 0000:00:1b.0: PME# disabled > pci 0000:00:1d.7: PME# supported from D0 D3hot D3cold > pci 0000:00:1d.7: PME# disabled > pci 0000:00:1f.0: quirk: region 0800-087f claimed by ICH6 ACPI/GPIO/TCO > pci 0000:00:1f.0: quirk: region 0480-04bf claimed by ICH6 GPIO > pci 0000:00:1f.0: ICH7 LPC Generic IO decode 1 PIO at 0294 (mask 0003) > pci 0000:00:1f.2: PME# supported from D3hot > pci 0000:00:1f.2: PME# disabled > pci 0000:02:02.0: PME# supported from D1 D2 D3hot D3cold > pci 0000:02:02.0: PME# disabled > pci 0000:00:1e.0: transparent bridge > pci 0000:00:1f.0: PIIX/ICH IRQ router [8086:2810] > > At this point the kernel hangs hard until rebooted. > > Rebooting with mem=2048M (to avoid issues with mappings >= 4GB) > allows PCI init to proceed and print: > > pci 0000:00:01.0: PCI bridge, secondary bus 0000:01 > pci 0000:00:01.0: IO window: 0x9000-0xbfff > pci 0000:00:01.0: MEM window: 0xff800000-0xff8fffff > pci 0000:00:01.0: PREFETCH window: 0x000000bff00000-0x000000dfefffff > pci 0000:00:1e.0: PCI bridge, secondary bus 0000:02 > pci 0000:00:1e.0: IO window: 0xc000-0xcfff > pci 0000:00:1e.0: MEM window: 0xff900000-0xff9fffff > pci 0000:00:1e.0: PREFETCH window: disabled > pci 0000:00:01.0: found PCI INT A -> IRQ 11 > pci 0000:00:01.0: sharing IRQ 11 with 0000:00:1a.0 > pci 0000:00:01.0: sharing IRQ 11 with 0000:01:00.0 > Unpacking initramfs... > Freeing initrd memory: 1233k freed > platform rtc_cmos: registered platform RTC device (no PNP device found) > Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled > serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A > Platform driver 'serial8250' needs updating - please use dev_pm_ops > Freeing unused kernel memory: 144k freed > Red Hat nash version 5.1.19.0.3 starting > ... > > Booting with pci=off also allows the kernel to boot. > Reconfiguring with NOHIGHMEM or HIGHMEM4G also allows the kernel to boot. > > This is a regression from 2.6.30 and earlier kernels. I've now identified commit 95ee14e4379c5e19c0897c872350570402014742 "x86: cap iomem_resource to addressable physical memory" by hpa (cc:d) as the culprit. Reverting it fixes my boot hang. That commit was: > x86: cap iomem_resource to addressable physical memory > > iomem_resource is by default initialized to -1, which means 64 bits of > physical address space if 64-bit resources are enabled. However, x86 > CPUs cannot address 64 bits of physical address space. Thus, we want > to cap the physical address space to what the union of all CPU can > actually address. > > Without this patch, we may end up assigning inaccessible values to > uninitialized 64-bit PCI memory resources. > > Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxx> > Cc: Matthew Wilcox <matthew@xxxxxx> > Cc: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> > Cc: Martin Mares <mj@xxxxxx> > Cc: stable@xxxxxxxxxx > --- > > diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c > index 3ffdcfa..5b9cb88 100644 > --- a/arch/x86/kernel/cpu/common.c > +++ b/arch/x86/kernel/cpu/common.c > @@ -853,6 +853,9 @@ static void __cpuinit identify_cpu(struct cpuinfo_x86 *c) > #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64) > numa_add_cpu(smp_processor_id()); > #endif > + > + /* Cap the iomem address space to what is addressable on all CPUs */ > + iomem_resource.end &= (1ULL << c->x86_phys_bits) - 1; > } > > #ifdef CONFIG_X86_64 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html