From: Jason Gunthorpe jgg@nvidia.com
[ Upstream commit 14351f08ed5c8b888cdd95651152db7e096ee27f ]
gcc 8.3 and 5.4 throw this:
In function 'modify_qp_init_to_rtr', ././include/linux/compiler_types.h:322:38: error: call to '__compiletime_assert_1859' declared with attribute error: FIELD_PREP: value too large for the field _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) [..] drivers/infiniband/hw/hns/hns_roce_common.h:91:52: note: in expansion of macro 'FIELD_PREP' *((__le32 *)ptr + (field_h) / 32) |= cpu_to_le32(FIELD_PREP( \ ^~~~~~~~~~ drivers/infiniband/hw/hns/hns_roce_common.h:95:39: note: in expansion of macro '_hr_reg_write' #define hr_reg_write(ptr, field, val) _hr_reg_write(ptr, field, val) ^~~~~~~~~~~~~ drivers/infiniband/hw/hns/hns_roce_hw_v2.c:4412:2: note: in expansion of macro 'hr_reg_write' hr_reg_write(context, QPC_LP_PKTN_INI, lp_pktn_ini);
Because gcc has miscalculated the constantness of lp_pktn_ini:
mtu = ib_mtu_enum_to_int(ib_mtu); if (WARN_ON(mtu < 0)) [..] lp_pktn_ini = ilog2(MAX_LP_MSG_LEN / mtu);
Since mtu is limited to {256,512,1024,2048,4096} lp_pktn_ini is between 4 and 8 which is compatible with the 4 bit field in the FIELD_PREP.
Work around this broken compiler by adding a 'can never be true' constraint on lp_pktn_ini's value which clears out the problem.
Fixes: f0cb411aad23 ("RDMA/hns: Use new interface to modify QP context") Link: https://lore.kernel.org/r/0-v1-c773ecb137bc+11f-hns_gcc8_jgg@nvidia.com Reported-by: Geert Uytterhoeven geert@linux-m68k.org Signed-off-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c index c320891c8763..6cb4a4e10837 100644 --- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c @@ -4411,7 +4411,12 @@ static int modify_qp_init_to_rtr(struct ib_qp *ibqp, hr_qp->path_mtu = ib_mtu;
mtu = ib_mtu_enum_to_int(ib_mtu); - if (WARN_ON(mtu < 0)) + if (WARN_ON(mtu <= 0)) + return -EINVAL; +#define MAX_LP_MSG_LEN 65536 + /* MTU * (2 ^ LP_PKTN_INI) shouldn't be bigger than 64KB */ + lp_pktn_ini = ilog2(MAX_LP_MSG_LEN / mtu); + if (WARN_ON(lp_pktn_ini >= 0xF)) return -EINVAL;
if (attr_mask & IB_QP_PATH_MTU) { @@ -4419,10 +4424,6 @@ static int modify_qp_init_to_rtr(struct ib_qp *ibqp, hr_reg_clear(qpc_mask, QPC_MTU); }
-#define MAX_LP_MSG_LEN 65536 - /* MTU * (2 ^ LP_PKTN_INI) shouldn't be bigger than 64KB */ - lp_pktn_ini = ilog2(MAX_LP_MSG_LEN / mtu); - hr_reg_write(context, QPC_LP_PKTN_INI, lp_pktn_ini); hr_reg_clear(qpc_mask, QPC_LP_PKTN_INI);