On Fri, Aug 3, 2012 at 8:38 PM, Kumar Gala <ga...@kernel.crashing.org> wrote: > > On Aug 2, 2012, at 9:21 PM, Jia Hongtao-B38951 wrote: > >>> >>> -----Original Message----- >>> From: Kumar Gala [mailto:ga...@kernel.crashing.org] >>> Sent: Thursday, August 02, 2012 8:55 PM >>> To: Jia Hongtao-B38951 >>> Cc: linuxppc-dev@lists.ozlabs.org; Wood Scott-B07421; Li Yang-R58472 >>> Subject: Re: [PATCH V4 2/3] powerpc/swiotlb: Enable at early stage and >>> disable if not necessary >>> >>> >>> On Aug 2, 2012, at 6:42 AM, Jia Hongtao wrote: >>> >>>> Remove the dependency on PCI initialization for SWIOTLB initialization. >>>> So that PCI can be initialized at proper time. >>>> >>>> SWIOTLB is partly determined by PCI inbound/outbound map which is >>> assigned >>>> in PCI initialization. But swiotlb_init() should be done at the stage >>> of >>>> mem_init() which is much earlier than PCI initialization. So we reserve >>> the >>>> memory for SWIOTLB first and free it if not necessary. >>>> >>>> All boards are converted to fit this change. >>>> >>>> Signed-off-by: Jia Hongtao <b38...@freescale.com> >>>> Signed-off-by: Li Yang <le...@freescale.com> >>>> --- >>> >>> This doesn't seem like it addresses our issue w/regards to not being able >>> to map all of memory from PCI. >> >> PCI init will determine ppc_swiotlb_enable due to PCI map. swiotlb_late_init >> will handle all swiotlb things depend on the result of pci init. > > Think about the case that we have 4095M of memory & 1G of PCI memory mapped > space. The old code would enable swiotlb for this case since we would NOT be > able to DMA to all 4095M of memory. The patch does not handle this case > correctly.
The patch can handle it. The ppc_swiotlb_enable is still being set in fsl_pci_init() if there is 1G of PCI memory mapped space. It is after next patch that the ppc_swiotlb_enable is being set in the PCI probe() routine. Leo _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
