On Mon, Aug 19, 2013 at 07:27:52PM -0500, Aravind Gopalakrishnan wrote: > Link to the bug report: > http://marc.info/?l=linux-edac&m=137692201732220&w=2 > > dct_base and dct_limit obtain 32 bit register values when they read their > respective pci config space registers. A left shift beyond 32 bits will > cause them to wrap around. Similar case for chan_addr as can be seen from > the bug report. In the patch, we rectify this by casting chan_addr to u64 > and by comparing dct_base and dct_limit against (sys_addr >> 27) > > Tested on F15h, M30h with ECC turned on and works fine. > > Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@xxxxxxx> > > diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c > index b86228c..eb4793e 100644 > --- a/drivers/edac/amd64_edac.c > +++ b/drivers/edac/amd64_edac.c > @@ -1558,11 +1558,12 @@ static int f15_m30h_match_to_this_node(struct amd64_pvt *pvt, unsigned range, > } > > /* Verify sys_addr is within DCT Range. */ > - dct_base = (dct_sel_baseaddr(pvt) << 27); > - dct_limit = (((dct_cont_limit_reg >> 11) & 0x1FFF) << 27) | 0x7FFFFFF; > + dct_base = dct_sel_baseaddr(pvt); This can't be correct. So the original patch takes the shifted dct_base while your change doesn't anymore... > + dct_limit = (dct_cont_limit_reg >> 11) & 0x1FFF; > > if (!(dct_cont_base_reg & BIT(0)) && > - !(dct_base <= sys_addr && dct_limit >= sys_addr)) > + !(dct_base <= (sys_addr >> 27) && > + dct_limit >= (sys_addr >> 27))) ... and while this comparison shifts sys_addr to use the proper bits, the code does this assignment later: chan_offset = dct_base; Now, chan_offset has the << 27 version of dct_base which makes the following calculation wrong: chan_addr = sys_addr - chan_offset; because sys_addr is the full 64-bit, unshifted value. The right thing to do would be to do: chan_offset = dct_base << 27; Or am I missing something? -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. -- -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
