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: [<ffffffff8026d377>] __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 <yhlu.kernel@gmail.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
index d0d18db..a614ee1 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -630,6 +630,7 @@
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 @@
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<<PAGE_SHIFT,
+ end_pfn<<PAGE_SHIFT);
+ if (max_pfn_mapped < max_low_pfn_mapped)
+ max_pfn_mapped = max_low_pfn_mapped;
+ }
return 0;
nommu:
