On Tue, Jan 14, 2020 at 11:06:52AM +0000, Will Deacon wrote:
> > /* Context descriptor manipulation functions */
> > +static int arm_smmu_alloc_cd_leaf_table(struct arm_smmu_device *smmu,
> > + struct arm_smmu_cd_table *table,
> > + size_t num_entries)
> > +{
> > + size_t size = num_entries * (CTXDESC_CD_DWORDS << 3);
> > +
> > + table->ptr = dmam_alloc_coherent(smmu->dev, size, &table->ptr_dma,
> > + GFP_KERNEL);
> > + if (!table->ptr) {
> > + dev_warn(smmu->dev,
> > + "failed to allocate context descriptor table\n");
> > + return -ENOMEM;
> > + }
> > + return 0;
> > +}
> > +
> > +static void arm_smmu_free_cd_leaf_table(struct arm_smmu_device *smmu,
> > + struct arm_smmu_cd_table *table,
> > + size_t num_entries)
> > +{
> > + size_t size = num_entries * (CTXDESC_CD_DWORDS << 3);
> > +
> > + dmam_free_coherent(smmu->dev, size, table->ptr, table->ptr_dma);
> > +}
>
> I think we'd be better off taking the 'arm_smmu_s1_cfg' as a parameter here
> instead of the table pointer and a num_entries value, since the code above
> implies that we support partial freeing of the context descriptors.
>
> I can do that as a follow-up patch if you agree. Thoughts?
Do you mean only changing the arguments of arm_smmu_free_cd_leaf_table(),
or arm_smmu_alloc_cd_leaf_table() as well? For free() I agree, for alloc()
I'm not sure it would look better.
For my tests I have a debug patch that allocates PASIDs randomly which
quickly consumes DMA for leaf tables. So I do have to free the leaves
individually when they aren't used, but it will be easy for me to update.
Thanks,
Jean
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