On 06/06/2022 10:30, John Garry wrote:
> Add the IOMMU callback for DMA mapping API dma_opt_mapping_size(), which
> allows the drivers to know the optimal mapping limit and thus limit the
> requested IOVA lengths.
>
> This value is based on the IOVA rcache range limit, as IOVAs allocated
> above this limit must always be newly allocated, which may be quite slow.
>
Can I please get some sort of ack from the IOMMU people on this one?
Thanks,
John
EOM
> Signed-off-by: John Garry <[email protected]>
> Reviewed-by: Damien Le Moal <[email protected]>
> ---
> drivers/iommu/dma-iommu.c | 6 ++++++
> drivers/iommu/iova.c | 5 +++++
> include/linux/iova.h | 2 ++
> 3 files changed, 13 insertions(+)
>
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index f90251572a5d..9e1586447ee8 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -1459,6 +1459,11 @@ static unsigned long iommu_dma_get_merge_boundary(struct device *dev)
> return (1UL << __ffs(domain->pgsize_bitmap)) - 1;
> }
>
> +static size_t iommu_dma_opt_mapping_size(void)
> +{
> + return iova_rcache_range();
> +}
> +
> static const struct dma_map_ops iommu_dma_ops = {
> .alloc = iommu_dma_alloc,
> .free = iommu_dma_free,
> @@ -1479,6 +1484,7 @@ static const struct dma_map_ops iommu_dma_ops = {
> .map_resource = iommu_dma_map_resource,
> .unmap_resource = iommu_dma_unmap_resource,
> .get_merge_boundary = iommu_dma_get_merge_boundary,
> + .opt_mapping_size = iommu_dma_opt_mapping_size,
> };
>
> /*
> diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
> index db77aa675145..9f00b58d546e 100644
> --- a/drivers/iommu/iova.c
> +++ b/drivers/iommu/iova.c
> @@ -26,6 +26,11 @@ static unsigned long iova_rcache_get(struct iova_domain *iovad,
> static void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad);
> static void free_iova_rcaches(struct iova_domain *iovad);
>
> +unsigned long iova_rcache_range(void)
> +{
> + return PAGE_SIZE << (IOVA_RANGE_CACHE_MAX_SIZE - 1);
> +}
> +
> static int iova_cpuhp_dead(unsigned int cpu, struct hlist_node *node)
> {
> struct iova_domain *iovad;
> diff --git a/include/linux/iova.h b/include/linux/iova.h
> index 320a70e40233..c6ba6d95d79c 100644
> --- a/include/linux/iova.h
> +++ b/include/linux/iova.h
> @@ -79,6 +79,8 @@ static inline unsigned long iova_pfn(struct iova_domain *iovad, dma_addr_t iova)
> int iova_cache_get(void);
> void iova_cache_put(void);
>
> +unsigned long iova_rcache_range(void);
> +
> void free_iova(struct iova_domain *iovad, unsigned long pfn);
> void __free_iova(struct iova_domain *iovad, struct iova *iova);
> struct iova *alloc_iova(struct iova_domain *iovad, unsigned long size,
On 14/06/2022 14:12, John Garry wrote:
> On 06/06/2022 10:30, John Garry wrote:
>> Add the IOMMU callback for DMA mapping API dma_opt_mapping_size(), which
>> allows the drivers to know the optimal mapping limit and thus limit the
>> requested IOVA lengths.
>>
>> This value is based on the IOVA rcache range limit, as IOVAs allocated
>> above this limit must always be newly allocated, which may be quite slow.
>>
>
> Can I please get some sort of ack from the IOMMU people on this one?
>
Another request for an ack please.
Thanks,
john
>
>> Signed-off-by: John Garry <[email protected]>
>> Reviewed-by: Damien Le Moal <[email protected]>
>> ---
>> drivers/iommu/dma-iommu.c | 6 ++++++
>> drivers/iommu/iova.c | 5 +++++
>> include/linux/iova.h | 2 ++
>> 3 files changed, 13 insertions(+)
>>
>> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
>> index f90251572a5d..9e1586447ee8 100644
>> --- a/drivers/iommu/dma-iommu.c
>> +++ b/drivers/iommu/dma-iommu.c
>> @@ -1459,6 +1459,11 @@ static unsigned long
>> iommu_dma_get_merge_boundary(struct device *dev)
>> return (1UL << __ffs(domain->pgsize_bitmap)) - 1;
>> }
>> +static size_t iommu_dma_opt_mapping_size(void)
>> +{
>> + return iova_rcache_range();
>> +}
>> +
>> static const struct dma_map_ops iommu_dma_ops = {
>> .alloc = iommu_dma_alloc,
>> .free = iommu_dma_free,
>> @@ -1479,6 +1484,7 @@ static const struct dma_map_ops iommu_dma_ops = {
>> .map_resource = iommu_dma_map_resource,
>> .unmap_resource = iommu_dma_unmap_resource,
>> .get_merge_boundary = iommu_dma_get_merge_boundary,
>> + .opt_mapping_size = iommu_dma_opt_mapping_size,
>> };
>> /*
>> diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
>> index db77aa675145..9f00b58d546e 100644
>> --- a/drivers/iommu/iova.c
>> +++ b/drivers/iommu/iova.c
>> @@ -26,6 +26,11 @@ static unsigned long iova_rcache_get(struct
>> iova_domain *iovad,
>> static void free_cpu_cached_iovas(unsigned int cpu, struct
>> iova_domain *iovad);
>> static void free_iova_rcaches(struct iova_domain *iovad);
>> +unsigned long iova_rcache_range(void)
>> +{
>> + return PAGE_SIZE << (IOVA_RANGE_CACHE_MAX_SIZE - 1);
>> +}
>> +
>> static int iova_cpuhp_dead(unsigned int cpu, struct hlist_node *node)
>> {
>> struct iova_domain *iovad;
>> diff --git a/include/linux/iova.h b/include/linux/iova.h
>> index 320a70e40233..c6ba6d95d79c 100644
>> --- a/include/linux/iova.h
>> +++ b/include/linux/iova.h
>> @@ -79,6 +79,8 @@ static inline unsigned long iova_pfn(struct
>> iova_domain *iovad, dma_addr_t iova)
>> int iova_cache_get(void);
>> void iova_cache_put(void);
>> +unsigned long iova_rcache_range(void);
>> +
>> void free_iova(struct iova_domain *iovad, unsigned long pfn);
>> void __free_iova(struct iova_domain *iovad, struct iova *iova);
>> struct iova *alloc_iova(struct iova_domain *iovad, unsigned long size,
>