| Message ID | 20210817113411.1962-1-thunder.leizhen@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iommu/arm-smmu-v3: Stop pre-zeroing batch commands in arm_smmu_atc_inv_master() | expand |
On 17/08/2021 12:34, Zhen Lei wrote: > Pre-zeroing the batched commands structure is inefficient, as individual > commands are zeroed later in arm_smmu_cmdq_build_cmd(). Therefore, only > the member 'num' needs to be initialized to 0. > > Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Reviewed-by: John Garry <john.garry@huawei.com> > --- > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > index 50a9db5bac466c7..e6882ae81fd08f6 100644 > --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > @@ -1776,10 +1776,11 @@ static int arm_smmu_atc_inv_master(struct arm_smmu_master *master) > { > int i; > struct arm_smmu_cmdq_ent cmd; > - struct arm_smmu_cmdq_batch cmds = {}; > + struct arm_smmu_cmdq_batch cmds; > > arm_smmu_atc_inv_to_cmd(0, 0, 0, &cmd); > > + cmds.num = 0; We prob should have added a comment why we do this (and at the other sites). I think Robin said something similar in another patch. > for (i = 0; i < master->num_streams; i++) { > cmd.atc.sid = master->streams[i].id; > arm_smmu_cmdq_batch_add(master->smmu, &cmds, &cmd); >
On Tue, 17 Aug 2021 19:34:11 +0800, Zhen Lei wrote: > Pre-zeroing the batched commands structure is inefficient, as individual > commands are zeroed later in arm_smmu_cmdq_build_cmd(). Therefore, only > the member 'num' needs to be initialized to 0. > > Applied to will (for-joerg/arm-smmu/updates), thanks! [1/1] iommu/arm-smmu-v3: Stop pre-zeroing batch commands in arm_smmu_atc_inv_master() https://git.kernel.org/will/c/93f9f7958f12 Cheers,
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index 50a9db5bac466c7..e6882ae81fd08f6 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -1776,10 +1776,11 @@ static int arm_smmu_atc_inv_master(struct arm_smmu_master *master) { int i; struct arm_smmu_cmdq_ent cmd; - struct arm_smmu_cmdq_batch cmds = {}; + struct arm_smmu_cmdq_batch cmds; arm_smmu_atc_inv_to_cmd(0, 0, 0, &cmd); + cmds.num = 0; for (i = 0; i < master->num_streams; i++) { cmd.atc.sid = master->streams[i].id; arm_smmu_cmdq_batch_add(master->smmu, &cmds, &cmd);
Pre-zeroing the batched commands structure is inefficient, as individual commands are zeroed later in arm_smmu_cmdq_build_cmd(). Therefore, only the member 'num' needs to be initialized to 0. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)