RE: DMA memory limitation?

Date: Fri Jul 06 2001 - 10:56:47 EST

> The important thing is that pci_alloc_consistent and the other PCI DMA
> functions work as advertised on IA64. If you pass NULL to
> pci_alloc_consistent, IA64 should give you an ISA DMA-able
> address. If
> you don't, you get a 32-bit PCI DMA address. Use of GFP_DMA is a
> arch-specific detail, so don't let me confuse you there.

Until recently, on IA-64, pci_alloc_consistent() given a NULL pci_dev would
fault. It's been fixed in at least the most recent IA-64 patch.
pci_map_single() and pci_map_sg() still have the same problem, as they
dereference pci_dev w/o checking for NULL first.

Matt Domsch
Sr. Software Engineer
Dell Linux Solutions
#2 Linux Server provider with 17% in the US and 14% Worldwide (IDC)!
#3 Unix provider with 18% in the US (Dataquest)!

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to More majordomo info at Please read the FAQ at

This archive was generated by hypermail 2b29 : Sat Jul 07 2001 - 21:00:18 EST