[PATCH AUTOSEL 4.19 42/52] libcxgb: fix incorrect ppmax calculation

Sasha Levin
2019-04-24T14:42:14Z

From: Varun Prakash <varun@chelsio.com>

[ Upstream commit cc5a726c79158bd307150e8d4176ec79b52001ea ]

BITS_TO_LONGS() uses DIV_ROUND_UP() because of
this ppmax value can be greater than available
per cpu page pods.

This patch removes BITS_TO_LONGS() to fix this
issue.

Signed-off-by: Varun Prakash <varun@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/chelsio/libcxgb/libcxgb_ppm.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/chelsio/libcxgb/libcxgb_ppm.c b/drivers/net/ethernet/chelsio/libcxgb/libcxgb_ppm.c
index 74849be5f004..e2919005ead3 100644
--- a/drivers/net/ethernet/chelsio/libcxgb/libcxgb_ppm.c
+++ b/drivers/net/ethernet/chelsio/libcxgb/libcxgb_ppm.c
@@ -354,7 +354,10 @@ static struct cxgbi_ppm_pool *ppm_alloc_cpu_pool(unsigned int *total,
ppmax = max;

/* pool size must be multiple of unsigned long */
- bmap = BITS_TO_LONGS(ppmax);
+ bmap = ppmax / BITS_PER_TYPE(unsigned long);
+ if (!bmap)
+ return NULL;
+
ppmax = (bmap * sizeof(unsigned long)) << 3;

alloc_sz = sizeof(*pools) + sizeof(unsigned long) * bmap;
@@ -402,6 +405,10 @@ int cxgbi_ppm_init(void **ppm_pp, struct net_device *ndev,
if (reserve_factor) {
ppmax_pool = ppmax / reserve_factor;
pool = ppm_alloc_cpu_pool(&ppmax_pool, &pool_index_max);
+ if (!pool) {
+ ppmax_pool = 0;
+ reserve_factor = 0;
+ }

pr_debug("%s: ppmax %u, cpu total %u, per cpu %u.\n",
ndev->name, ppmax, ppmax_pool, pool_index_max);
--
2.19.1