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| author | Jason Gunthorpe <jgg@nvidia.com> | 2021-09-16 18:05:28 +0300 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@nvidia.com> | 2021-09-24 14:47:55 +0300 |
| commit | 14351f08ed5c8b888cdd95651152db7e096ee27f (patch) | |
| tree | 19344f2779e267c4ff9ebc68feb91cc78b545364 /drivers/infiniband | |
| parent | 305d568b72f17f674155a2a8275f865f207b3808 (diff) | |
| download | linux-14351f08ed5c8b888cdd95651152db7e096ee27f.tar.xz | |
RDMA/hns: Work around broken constant propagation in gcc 8
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>
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 11 |
1 files 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 5b9953105752..a9c00a2e8ebd 100644 --- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c @@ -4397,7 +4397,12 @@ 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) { @@ -4405,10 +4410,6 @@ 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); |