On Wed, Nov 02, 2011 at 09:16:34AM +0200, Michael S. Tsirkin wrote: > On Mon, Oct 31, 2011 at 05:06:49PM +1100, David Gibson wrote: > > From: Eduard - Gabriel Munteanu <eduard.munte...@linux360.ro> [snip] > > @@ -744,21 +713,26 @@ static void dump_statistics(EEPRO100State * s) > > * values which really matter. > > * Number of data should check configuration!!! > > */ > > - cpu_physical_memory_write(s->statsaddr, &s->statistics, s->stats_size); > > - e100_stl_le_phys(s->statsaddr + 0, s->statistics.tx_good_frames); > > - e100_stl_le_phys(s->statsaddr + 36, s->statistics.rx_good_frames); > > - e100_stl_le_phys(s->statsaddr + 48, s->statistics.rx_resource_errors); > > - e100_stl_le_phys(s->statsaddr + 60, > > s->statistics.rx_short_frame_errors); > > + pci_dma_write(&s->dev, s->statsaddr, > > + (uint8_t *) &s->statistics, s->stats_size); > > + stl_le_pci_dma(&s->dev, s->statsaddr + 0, > > + s->statistics.tx_good_frames); > > + stl_le_pci_dma(&s->dev, s->statsaddr + 36, > > + s->statistics.rx_good_frames); > > + stl_le_pci_dma(&s->dev, s->statsaddr + 48, > > + s->statistics.rx_resource_errors); > > + stl_le_pci_dma(&s->dev, s->statsaddr + 60, > > + s->statistics.rx_short_frame_errors); > > This might introduce a bug: stlXX APIs assume aligned addresses, > an address in statsaddr is user-controlled so I'm not sure > it's always aligned. > > Why isn't the patch simply replacing cpu_physical_memory_read > with pci_XXX ? Any cleanups should be done separately.
Because it seemed like a good idea at the time. When I first wrote this, the possibility of unaligned addresses wasn't obvious to me. So, I'm working on fixing this now. I can take one of two approaches: - Simply revert this part of the change, reinstate the e100_stl functions as calling into dma_write(). - Alter the stX_dma() functions to work for unaligned addresses (by falling back to dma_rw() in that case). This is a little more involved but might make device writing safer in future. Anthony, Michael, any preferred direction here? -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson