[PATCH 4.15 092/168] cxgb4vf: Fix SGE FL buffer initialization logic for 64K pages

From: Greg Kroah-Hartman
Date: Tue Apr 10 2018 - 19:25:26 EST


4.15-stable review patch. If anyone has any objections, please let me know.

------------------

From: Arjun Vynipadath <arjun@xxxxxxxxxxx>


[ Upstream commit ea0a42109aee7b92e631c4eb3f2219fadf58acdd ]

We'd come in with SGE_FL_BUFFER_SIZE[0] and [1] both equal to 64KB and
the extant logic would flag that as an error. This was already fixed in
cxgb4 driver with "92ddcc7 cxgb4: Fix some small bugs in
t4_sge_init_soft() when our Page Size is 64KB".

Original Work by: Casey Leedom <leedom@xxxxxxxxxxx>
Signed-off-by: Arjun Vynipadath <arjun@xxxxxxxxxxx>
Signed-off-by: Ganesh Goudar <ganeshgr@xxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/chelsio/cxgb4vf/sge.c | 23 +++++++++++++++++------
1 file changed, 17 insertions(+), 6 deletions(-)

--- a/drivers/net/ethernet/chelsio/cxgb4vf/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb4vf/sge.c
@@ -2619,8 +2619,8 @@ void t4vf_sge_stop(struct adapter *adapt
int t4vf_sge_init(struct adapter *adapter)
{
struct sge_params *sge_params = &adapter->params.sge;
- u32 fl0 = sge_params->sge_fl_buffer_size[0];
- u32 fl1 = sge_params->sge_fl_buffer_size[1];
+ u32 fl_small_pg = sge_params->sge_fl_buffer_size[0];
+ u32 fl_large_pg = sge_params->sge_fl_buffer_size[1];
struct sge *s = &adapter->sge;

/*
@@ -2628,9 +2628,20 @@ int t4vf_sge_init(struct adapter *adapte
* the Physical Function Driver. Ideally we should be able to deal
* with _any_ configuration. Practice is different ...
*/
- if (fl0 != PAGE_SIZE || (fl1 != 0 && fl1 <= fl0)) {
+
+ /* We only bother using the Large Page logic if the Large Page Buffer
+ * is larger than our Page Size Buffer.
+ */
+ if (fl_large_pg <= fl_small_pg)
+ fl_large_pg = 0;
+
+ /* The Page Size Buffer must be exactly equal to our Page Size and the
+ * Large Page Size Buffer should be 0 (per above) or a power of 2.
+ */
+ if (fl_small_pg != PAGE_SIZE ||
+ (fl_large_pg & (fl_large_pg - 1)) != 0) {
dev_err(adapter->pdev_dev, "bad SGE FL buffer sizes [%d, %d]\n",
- fl0, fl1);
+ fl_small_pg, fl_large_pg);
return -EINVAL;
}
if ((sge_params->sge_control & RXPKTCPLMODE_F) !=
@@ -2642,8 +2653,8 @@ int t4vf_sge_init(struct adapter *adapte
/*
* Now translate the adapter parameters into our internal forms.
*/
- if (fl1)
- s->fl_pg_order = ilog2(fl1) - PAGE_SHIFT;
+ if (fl_large_pg)
+ s->fl_pg_order = ilog2(fl_large_pg) - PAGE_SHIFT;
s->stat_len = ((sge_params->sge_control & EGRSTATUSPAGESIZE_F)
? 128 : 64);
s->pktshift = PKTSHIFT_G(sge_params->sge_control);