ioremap_wc sending 64 bytes only

Question

I am using ioremap_wc in PCIe driver, it seems in payload only 64 bytes going at a time from x86, how can i send more data in payload.

I am using ioremap_wc in PCIe driver, it seems in payload only 64 bytes going at a time from x86, how can I send more data in payload. how can I send 256 bytes in payload.