Messages in this thread |  | | | Date | Mon, 14 Jun 2010 17:27:32 +0900 | | From | Kenji Kaneshige <> | | Subject | Re: [PATCH 2/4] x86: ioremap: fix physical address check |
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> Do you mean x86 linux can map physical address higher than 36-bit for I/O? > My understanding is as follows. > - Architectural limit of physical address in x86 32-bit mode is 40-bit > (depnds on processor version). > - The maximum physical address supported by current x86 linux kernel in > 32-bit mode is 36-bit. > On my environment, physical address higher than 40-bit (ex. 0xfc00001c000) > is assigned to some PCI devices. I think there is no way to handle such > high physical address in 32-bit mode. > > Thanks, > Kenji Kaneshige
Please ignore above. I misunderstood the architectural limit of physical address in x86 32-bit mode. It is not 40-bits, but 52-bits.
Thanks, Kenji Kaneshige
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