cxgb4vf: Make sge init code more readable

Adds a new function t4vf_fl_pkt_align() and use the same in SGE
initialization code to find out freelist packet alignment

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 55 insertions, 0 deletions

diff --git a/drivers/net/ethernet/chelsio/cxgb4vf/t4vf_hw.c b/drivers/net/ethernet/chelsio/cxgb4vf/t4vf_hw.c
index 54220117dcba..fed83d88fc4e 100644
--- a/drivers/net/ethernet/chelsio/cxgb4vf/t4vf_hw.c
+++ b/drivers/net/ethernet/chelsio/cxgb4vf/t4vf_hw.c
@@ -418,6 +418,61 @@ int t4vf_set_params(struct adapter *adapter, unsigned int nparams,
 }
 
 /**
+ *	t4vf_fl_pkt_align - return the fl packet alignment
+ *	@adapter: the adapter
+ *
+ *	T4 has a single field to specify the packing and padding boundary.
+ *	T5 onwards has separate fields for this and hence the alignment for
+ *	next packet offset is maximum of these two.  And T6 changes the
+ *	Ingress Padding Boundary Shift, so it's all a mess and it's best
+ *	if we put this in low-level Common Code ...
+ *
+ */
+int t4vf_fl_pkt_align(struct adapter *adapter)
+{
+	u32 sge_control, sge_control2;
+	unsigned int ingpadboundary, ingpackboundary, fl_align, ingpad_shift;
+
+	sge_control = adapter->params.sge.sge_control;
+
+	/* 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.  (Note that it makes no real practical sense to
+	 * have the Pading Boudary be larger than the Packing Boundary but you
+	 * could set the chip up that way and, in fact, legacy T4 code would
+	 * end doing this because it would initialize the Padding Boundary and
+	 * leave the Packing Boundary initialized to 0 (16 bytes).)
+	 * Padding Boundary values in T6 starts from 8B,
+	 * where as it is 32B for T4 and T5.
+	 */
+	if (CHELSIO_CHIP_VERSION(adapter->params.chip) <= CHELSIO_T5)
+		ingpad_shift = INGPADBOUNDARY_SHIFT_X;
+	else
+		ingpad_shift = T6_INGPADBOUNDARY_SHIFT_X;
+
+	ingpadboundary = 1 << (INGPADBOUNDARY_G(sge_control) + ingpad_shift);
+
+	fl_align = ingpadboundary;
+	if (!is_t4(adapter->params.chip)) {
+		/* T5 has a different interpretation of one of the PCIe Packing
+		 * Boundary values.
+		 */
+		sge_control2 = adapter->params.sge.sge_control2;
+		ingpackboundary = INGPACKBOUNDARY_G(sge_control2);
+		if (ingpackboundary == INGPACKBOUNDARY_16B_X)
+			ingpackboundary = 16;
+		else
+			ingpackboundary = 1 << (ingpackboundary +
+						INGPACKBOUNDARY_SHIFT_X);
+
+		fl_align = max(ingpadboundary, ingpackboundary);
+	}
+	return fl_align;
+}
+
+/**
  *	t4vf_bar2_sge_qregs - return BAR2 SGE Queue register information
  *	@adapter: the adapter
  *	@qid: the Queue ID