Hello PPC-developers, I'm currently trying to benchmark access speeds to our PCIe-connected IP-cores located inside our FPGA. On x86-based systems I was able to achieve bursts for both read and write access. On PPC32, using an e500v2, I had no success at all so far. I tried using ioremap_wc(), like I did on x86, for writing, and it only results in my writes just being single requests, one after another. For reads, I noticed I could not ioremap_cache() on PPC, so I used simple ioremap() here. I used several ways to read from the device, from simple readl(),memcpy_from_io(), memcpy() to cacheable_memcpy() - with no improvements. Even when just issuing a batch of prefetch()-calls for all the memory to read did not result in read bursts.
I only get really poor results, writing is possible with around 40 MiByte/s, whereas I can read at about only 3 MiByte/s. After hours of studying the reference manual from freescale, looking into other code and searching the web, I'm close to resignation. Maybe someone of you has some more directions for me, I'd appreciate every hint that leads me to my problem's solution - maybe I just missed something or lack knowledge about this architecture in general. Thanks for your reading. Michael _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
