Re: [BUG 2.6.31-rc1] HIGHMEM64G causes hang in PCI init on 32-bitx86
From: H. Peter Anvin
Date: Sat Jun 27 2009 - 00:57:48 EST
Can you send me /proc/cpuinfo and /proc/iomem from this box?
-hpa
Mikael Pettersson wrote:
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
--
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