Messages in this thread | | | Date | Tue, 10 Apr 2007 09:43:26 -0700 | From | Ashok Raj <> | Subject | Re: [patch 0/8] [Intel IOMMU] Support for Intel Virtualization Technology for Directed I/O |
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On Tue, Apr 10, 2007 at 04:34:48AM -0400, Jeff Garzik wrote: > Shaohua Li wrote: > >DMA remapping just uses ACPI table to tell which dma remapping engine a > >pci device is controlled by at boot time. At run time, DMA remapping > >hasn't any interactive with ACPI. > > The Linux kernel _really_ wants a non-ACPI way to detect this. > > Just use the hardware registers themselves, you don't need an ACPI table. > > Jeff
ACPI is required just not for identifying the DMA remapping hardware in the system. We also need them to identify which engines control which pci devices.
Also there are some reserved sections that BIOS uses for its purpose that it needs identity map.. say for legacy emulation via usb etc that needs to be passed to the OS.
not sure we can get away from using ACPI that easily.. its just only for setup information, once the identification is complete we dont bother ACPI anymore. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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