cxgb4/cxgb4vf: For T5 use Packing and Padding Boundaries for SGE DMA transfers
T5 introduces the ability to have separate Packing and Padding Boundaries
for SGE DMA transfers from the chip to Host Memory. This change set takes
advantage of that to set up a smaller Padding Boundary to conserve PCI Link
and Memory Bandwidth with T5.
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/chelsio/cxgb4/sge.c b/drivers/net/ethernet/chelsio/cxgb4/sge.c
index 5e1b314..39f2b13 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/sge.c
@@ -2914,7 +2914,8 @@
int t4_sge_init(struct adapter *adap)
{
struct sge *s = &adap->sge;
- u32 sge_control, sge_conm_ctrl;
+ u32 sge_control, sge_control2, sge_conm_ctrl;
+ unsigned int ingpadboundary, ingpackboundary;
int ret, egress_threshold;
/*
@@ -2924,8 +2925,31 @@
sge_control = t4_read_reg(adap, SGE_CONTROL);
s->pktshift = PKTSHIFT_GET(sge_control);
s->stat_len = (sge_control & EGRSTATUSPAGESIZE_MASK) ? 128 : 64;
- s->fl_align = 1 << (INGPADBOUNDARY_GET(sge_control) +
- X_INGPADBOUNDARY_SHIFT);
+
+ /* T4 uses a single control field to specify both the PCIe Padding and
+ * Packing Boundary. T5 introduced the ability to specify these
+ * separately. The actual Ingress Packet Data alignment boundary
+ * within Packed Buffer Mode is the maximum of these two
+ * specifications.
+ */
+ ingpadboundary = 1 << (INGPADBOUNDARY_GET(sge_control) +
+ X_INGPADBOUNDARY_SHIFT);
+ if (is_t4(adap->params.chip)) {
+ s->fl_align = ingpadboundary;
+ } else {
+ /* T5 has a different interpretation of one of the PCIe Packing
+ * Boundary values.
+ */
+ sge_control2 = t4_read_reg(adap, SGE_CONTROL2_A);
+ ingpackboundary = INGPACKBOUNDARY_G(sge_control2);
+ if (ingpackboundary == INGPACKBOUNDARY_16B_X)
+ ingpackboundary = 16;
+ else
+ ingpackboundary = 1 << (ingpackboundary +
+ INGPACKBOUNDARY_SHIFT_X);
+
+ s->fl_align = max(ingpadboundary, ingpackboundary);
+ }
if (adap->flags & USING_SOFT_PARAMS)
ret = t4_sge_init_soft(adap);