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authorHariprasad Shenai <hariprasad@chelsio.com>2014-11-07 12:36:30 +0100
committerDavid S. Miller <davem@davemloft.net>2014-11-10 20:15:03 +0100
commitce8f407a3cc7fc58804b9135e7c8780f0f8c2a8d (patch)
treeadaef931f4064d2969ca78d987dccace85607d3a /drivers/net/ethernet/chelsio/cxgb4/sge.c
parentcxgb4vf: Move fl_starv_thres into adapter->sge data structure (diff)
downloadlinux-ce8f407a3cc7fc58804b9135e7c8780f0f8c2a8d.tar.xz
linux-ce8f407a3cc7fc58804b9135e7c8780f0f8c2a8d.zip
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>
Diffstat (limited to 'drivers/net/ethernet/chelsio/cxgb4/sge.c')
-rw-r--r--drivers/net/ethernet/chelsio/cxgb4/sge.c30
1 files changed, 27 insertions, 3 deletions
diff --git a/drivers/net/ethernet/chelsio/cxgb4/sge.c b/drivers/net/ethernet/chelsio/cxgb4/sge.c
index 5e1b314e11af..39f2b13e66c7 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/sge.c
@@ -2914,7 +2914,8 @@ static int t4_sge_init_hard(struct adapter *adap)
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 @@ int t4_sge_init(struct adapter *adap)
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);