From 7ab073b6e0cde1544f4e79fadb75532528af7595 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Sat, 12 Jul 2008 14:30:35 -0700 Subject: [PATCH] x86: max_low_pfn_mapped fix, #1 fix crash on Ingo's big box: calling pci_iommu_init+0x0/0x17 PCI-DMA: Disabling AGP. PCI-DMA: aperture base @ d0000000 size 65536 KB PCI-DMA: using GART IOMMU. PCI-DMA: Reserving 64MB of IOMMU area in the AGP aperture BUG: unable to handle kernel paging request at ffff88000003be88 IP: [] __alloc_pages_internal+0xc3/0x3f2 PGD 202063 PUD 206063 PMD 22fc00163 PTE 3b162 Oops: 0000 [1] SMP and e820 is: BIOS-e820: 0000000000000000 - 000000000009ac00 (usable) BIOS-e820: 000000000009ac00 - 00000000000a0000 (reserved) BIOS-e820: 00000000000ca000 - 0000000000100000 (reserved) BIOS-e820: 0000000000100000 - 000000007ff70000 (usable) BIOS-e820: 000000007ff70000 - 000000007ff86000 (ACPI data) BIOS-e820: 000000007ff86000 - 0000000080000000 (ACPI NVS) BIOS-e820: 0000000080000000 - 00000000cfe00000 (usable) BIOS-e820: 00000000cfe00000 - 00000000d0000000 (reserved) BIOS-e820: 00000000e0000000 - 00000000f0000000 (reserved) BIOS-e820: 00000000fec00000 - 00000000fec10000 (reserved) BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved) BIOS-e820: 00000000fff80000 - 0000000100000000 (reserved) BIOS-e820: 0000000100000000 - 0000000830000000 (usable) system has 32 GB RAM installed. max_low_pfn_mapped is 0xcfe00, and GART aperture is not mapped. So try to use init_memory_mapping to map that area, because the iommu thinks that area is ram ... Signed-off-by: Yinghai Lu Cc: Suresh Siddha Signed-off-by: Ingo Molnar --- arch/x86/kernel/pci-gart_64.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c index d0d18db5d2..a614ee10f8 100644 --- a/arch/x86/kernel/pci-gart_64.c +++ b/arch/x86/kernel/pci-gart_64.c @@ -630,6 +630,7 @@ static __init int init_k8_gatt(struct agp_kern_info *info) struct pci_dev *dev; void *gatt; int i, error; + unsigned long start_pfn, end_pfn; printk(KERN_INFO "PCI-DMA: Disabling AGP.\n"); aper_size = aper_base = info->aper_size = 0; @@ -674,6 +675,16 @@ static __init int init_k8_gatt(struct agp_kern_info *info) printk(KERN_INFO "PCI-DMA: aperture base @ %x size %u KB\n", aper_base, aper_size>>10); + + /* need to map that range */ + end_pfn = (aper_base>>PAGE_SHIFT) + (aper_size>>PAGE_SHIFT); + if (end_pfn > max_low_pfn_mapped) { + start_pfn = max_low_pfn_mapped; + max_low_pfn_mapped = init_memory_mapping(start_pfn<