Re: [PATCH v4 06/13] iommu/arm-smmu-v3: Add context descriptor tables allocators
On Tue, Jan 14, 2020 at 12:52:30PM +0100, Jean-Philippe Brucker wrote:
> On Tue, Jan 14, 2020 at 11:06:52AM +, 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, >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.
Yeah, just for free(). I'll spin something on top after I've finished
reviewing the series.
> 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.
Cool.
Will
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Re: [PATCH v4 06/13] iommu/arm-smmu-v3: Add context descriptor tables allocators
On Tue, Jan 14, 2020 at 11:06:52AM +, 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, >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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Re: [PATCH v4 06/13] iommu/arm-smmu-v3: Add context descriptor tables allocators
On Thu, Dec 19, 2019 at 05:30:26PM +0100, Jean-Philippe Brucker wrote:
> Support for SSID will require allocating context descriptor tables. Move
> the context descriptor allocation to separate functions.
>
> Reviewed-by: Eric Auger
> Reviewed-by: Jonathan Cameron
> Signed-off-by: Jean-Philippe Brucker
> ---
> drivers/iommu/arm-smmu-v3.c | 57 ++---
> 1 file changed, 46 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index b287e303b1d7..43d6a7ded6e4 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -568,6 +568,7 @@ struct arm_smmu_cd_table {
> struct arm_smmu_s1_cfg {
> struct arm_smmu_cd_tabletable;
> struct arm_smmu_ctx_desccd;
> + u8 s1cdmax;
> };
>
> struct arm_smmu_s2_cfg {
> @@ -1455,6 +1456,31 @@ static int arm_smmu_cmdq_issue_sync(struct
> arm_smmu_device *smmu)
> }
>
> /* 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, >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?
Will
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