On Mon, Dec 18, 2017 at 11:25:06AM -0700, Logan Gunthorpe wrote: > With Switchtec hardware, the buffer used for a memory window must be > aligned to its size (the hardware only replaces the lower bits). In > certain circumstances dma_alloc_coherent() will not provide a buffer > that adheres to this requirement like when using the CMA and > CONFIG_CMA_ALIGNMENT is set lower than the buffer size. > > When we get an unaligned buffer mw_set_trans() should return an error. > We also log an error so we know the cause of the problem. >
Applied to ntb-next. Thanks, Jon > Signed-off-by: Logan Gunthorpe <[email protected]> > Cc: Jon Mason <[email protected]> > --- > > v2: Use IS_ALIGNED macro as suggested by Allen > > drivers/ntb/hw/mscc/ntb_hw_switchtec.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c > b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c > index bcd5b6fb3800..6c6f991999b5 100644 > --- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c > +++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c > @@ -320,6 +320,19 @@ static int switchtec_ntb_mw_set_trans(struct ntb_dev > *ntb, int pidx, int widx, > if (xlate_pos < 12) > return -EINVAL; > > + if (!IS_ALIGNED(addr, BIT_ULL(xlate_pos))) { > + /* > + * In certain circumstances we can get a buffer that is > + * not aligned to its size. (Most of the time > + * dma_alloc_coherent ensures this). This can happen when > + * using large buffers allocated by the CMA > + * (see CMA_CONFIG_ALIGNMENT) > + */ > + dev_err(&sndev->stdev->dev, > + "ERROR: Memory window address is not aligned to it's > size!\n"); > + return -EINVAL; > + } > + > rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK, > NTB_CTRL_PART_STATUS_LOCKED); > if (rc) > -- > 2.11.0 > > -- > You received this message because you are subscribed to the Google Groups > "linux-ntb" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/linux-ntb/20171218182506.5219-2-logang%40deltatee.com. > For more options, visit https://groups.google.com/d/optout.
