>Subject: Re: [PATCH v3 rdma-next 6/6] RDMA/verbs: Extend DMA block iterator
>support for mixed block sizes
>
>On Mon, May 06, 2019 at 08:53:37AM -0500, Shiraz Saleem wrote:
>> Extend the DMA block iterator for HW that can support mixed block
>> sizes. A bitmap of HW supported page sizes are provided to block
>> iterator which returns contiguous aligned memory blocks within a HW
>> supported page size.
>>
>> Signed-off-by: Shiraz Saleem <shiraz.saleem@xxxxxxxxx>
>> drivers/infiniband/core/verbs.c | 38
>++++++++++++++++++++++++++++++++++++--
>> include/rdma/ib_verbs.h | 18 ++++++++++++++----
>> 2 files changed, 50 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/infiniband/core/verbs.c
>> b/drivers/infiniband/core/verbs.c index 3806038..fa9725d 100644
>> +++ b/drivers/infiniband/core/verbs.c
>> @@ -2712,16 +2712,47 @@ int rdma_init_netdev(struct ib_device *device,
>> u8 port_num, } EXPORT_SYMBOL(rdma_init_netdev);
>>
>> +static unsigned int rdma_find_mixed_pg_bit(struct ib_block_iter
>> +*biter) {
>> + if (biter->__sg == biter->__sgl_head) {
>> + return rdma_find_pg_bit(sg_dma_address(biter->__sg) +
>> + sg_dma_len(biter->__sg),
>> + biter->pgsz_bitmap);
>> + } else if (sg_is_last(biter->__sg)) {
>> + return rdma_find_pg_bit(sg_dma_address(biter->__sg),
>> + biter->pgsz_bitmap);
>> + } else {
>> + unsigned int remaining =
>> + sg_dma_address(biter->__sg) + sg_dma_len(biter->__sg)
>-
>> + biter->__dma_addr;
>> + unsigned int pg_bit = rdma_find_pg_bit(biter->__dma_addr,
>> + biter->pgsz_bitmap);
>> + if (remaining < BIT_ULL(biter->__pg_bit))
>> + pg_bit = rdma_find_pg_bit(remaining,
>> + biter->pgsz_bitmap);
>
>I think this needs to follow the same basic algorithm as the single bit case,
>considering the IOVA/etc.
>
>But there is no user, so let us just drop this patch until a user appears..
>
Sure. Let's wait for a user. Updating the algo to consider IOVA is do-able.
Shiraz
