[Linux-ia64] RE: DMA memory limitation?

["White, Charles" <Charles.White@COMPAQ.com>]

Is there a patch that fixes the pci_alloc_consistent for older versions of
the IA-64 kernels?  To do 64bit DMA in my driver I need to pass
pci_alloc_consistent pci_dev pointer of NULL.  

I'm interested in getting this to work on the older IA64 kernels that are
currently on distribution CDs. 
		

		From: Matt_Domsch@Dell.com
		To: jgarzik@mandrakesoft.com, sp@scali.no
		Cc: alan@lxorguk.ukuu.org.uk, helgehaf@idb.hist.no, 
			pvvvarma@techmas.hcltech.com,
linux-kernel@vger.kernel.org, 
			davem@redhat.com, linux-ia64@linuxia64.org
		Date: Fri, 6 Jul 2001 10:56:47 -0500 
		Subject: [Linux-ia64] RE: DMA memory limitation?

		> 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
		www.dell.com/linux
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