Hi Kishon, On Mon, Mar 30, 2020 at 2:21 PM Kishon Vijay Abraham I <kishon@xxxxxx> wrote: > > Prabhakar, > > On 3/30/2020 6:39 PM, Lad, Prabhakar wrote: > > Hi Kishon, > > > > On Mon, Mar 30, 2020 at 12:59 PM Kishon Vijay Abraham I <kishon@xxxxxx> wrote: > >> > >> Hi Prabhakar, > >> > >> On 3/29/2020 7:34 PM, Lad, Prabhakar wrote: > >>> Hi Kishon, > >>> > >>> On Sat, Mar 28, 2020 at 6:44 PM Lad, Prabhakar > >>> <prabhakar.csengg@xxxxxxxxx> wrote: > >>>> > >>>> Hi Kishon, > >>>> > >>>> On Tue, Mar 24, 2020 at 2:41 PM Lad, Prabhakar > >>>> <prabhakar.csengg@xxxxxxxxx> wrote: > >>>>> > >>>>> Hi Kishon, > >>>>> > >>>>> On Tue, Mar 24, 2020 at 1:58 AM Kishon Vijay Abraham I <kishon@xxxxxx> wrote: > >>>>>> > >>>>>> Hi Prabhakar, > >>>>>> > >>>>>> On 3/22/2020 4:19 AM, Lad, Prabhakar wrote: > >>>>>>> Hi Kishon, > >>>>>>> > >>>>>>> On Fri, Mar 20, 2020 at 5:28 AM Kishon Vijay Abraham I <kishon@xxxxxx> wrote: > >>>>>>>> > >>>>>>>> Hi Prabhakar, > >>>>>>>> > >>>>>>>> On 3/18/2020 5:07 PM, Lad, Prabhakar wrote: > >>>>>>>>> Hi Kishon, > >>>>>>>>> > >>>>>>>>> I rebased my rcar-endpoint patches on endpoint branch, which has > >>>>>>>>> support for streaming DMA API support, with this read/write/copy > >>>>>>>>> tests failed, to make sure nothing hasn't changed on my driver I > >>>>>>>>> reverted the streaming DMA API patch > >>>>>>>>> 74b9b4da84c71418ceeaaeb78dc790376df92fea "misc: pci_endpoint_test: Use > >>>>>>>>> streaming DMA APIs for buffer allocation" and tests began to pass > >>>>>>>>> again. > >>>>>>>>> > >>>>>>>>> If add a GFP_DMA flag for kzalloc (with streaming DMA), the test cases > >>>>>>>>> for read/write/copy pass as expected. > >>>>>>>>> > >>>>>>>>> Could you please through some light why this could be happening. > >>>>>>>> > >>>>>>>> Do you see any differences in the address returned by dma_map_single() like is > >>>>>>>> it 32-bit address or 64-bit address? > >>>>>>>> > >>>>>>> Both return 32 bit address, debugging further I see that with > >>>>>>> GFP_KERNEL flag for small buffer > >>>>>>> sizes the read/write/copy tests pass(upto 4k), so I am suspecting its > >>>>>>> related to caching probably. > >>>>>>> Also adding wmb()/rmb() just with GFP_KERNEL flag didn't help. Note I > >>>>>>> am using PIO transfers. > >>>>>>> Any thoughts on how we tackle it ? > >>>>>>> > >>>>>>> # With GFP_KERNEL flag > >>>>>>> root@hihope-rzg2m:~# pcitest -r > >>>>>>> [ 46.210649] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > >>>>>>> kzalloc:ffff0004b4ae0000 dma:7e99d000 align:ffff0004b4ae0000 > >>>>>>> READ ( 102400 bytes): NOT OKAY > >>>>>>> root@hihope-rzg2m:~# pcitest -r > >>>>>>> [ 51.880063] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > >>>>>>> kzalloc:ffff0004b4ae0000 dma:7e9c0000 align:ffff0004b4ae0000 > >>>>>>> READ ( 102400 bytes): OKAY > >>>>>> > >>>>>> Here one of the read test is passing and the other is failing. > >>>>>> For the 1st case dma:7e99d000, address is aligned to 4K > >>>>>> For the 2nd case dma:7e9c0000, address is aligned to 256K > >>>>>> > >>>>>> I'm suspecting this could be an alignment issue. Does the outbound ATU of your > >>>>>> EP has any restrictions? (like the address should be aligned to the size?). > >>>>>> > >>>>> There isn't any restriction for outbound ATU on ep, Although I tried > >>>>> alignment from > >>>>> SZ_1 - SZ_256K and each failed at several points. > >>>>> > >>>>> With GFP_KERNEL | GFP_DMA, as in my previous dump here the address too > >>>>> is not aligned to 256 but still read passes. > >>>>> root@hihope-rzg2m:~# pcitest -r -s 16384 > >>>>> [ 186.629347] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > >>>>> kzalloc:ffff00003b848000 dma:7b848000 align:ffff00003b848000 > >>>>> READ ( 16384 bytes): OKAY > >>>>> > >>>>> And I have verified with GFP_KERNEL | GFP_DMA on my platform > >>>>> everything works as expected, > >>>>> > >>>>> So how about a patch for pci_endpoint_test.c, where flags are passed > >>>>> as part of driver_data and it defaults to just GFP_KERNEL ? > >>>>> > >>>> Any thoughts on the above ? I intended to get the endpoint driver for v5.7. > >>>> > >>> Correct me if I am wrong here, streaming DMA API should be used with > >>> dma (-d) option so that root device > >>> makes sure the data is synced when data is transferred whereas > >>> previously with dma_alloc_coherent() > >>> we didn't have to care about cache issues. Also for a non-dma (-d) > >>> option we don't have a handle to dma > >>> in rootpport device so that we can call a sync operation. I say this > >>> because on my platform with streaming > >>> DMA api it works for small size buffers but it doesn't work with large > >>> size buffers. > >> > >> Streaming DMA API and DMA support in endpoint can be treated independently. > >> dma_alloc_coherent() will give you coherent memory, so you don't have to flush > >> or invalidate. This memory is usually limited in a platform. > >> The other option was to use streaming DMA APIs which doesn't give coherent > >> memory but SW has to take care of flush and invalidate. > >> > > Agreed. But we don't flush in SW when -d option is not specified I am > > assuming when we us > > -d dma engine takes care of flushing it. > > The -d option switch doesn't change anything on the SW that runs on the host > side (misc/pci-endpoint-test.c). That only tells the EP to use DMA. > > When you use streaming APIs, dma_map_single(), dmap_unmap_single() takes care > of flushing or invalidating memory based on the platform. (Platforms which have > coherent memory will have dma-coherent property, > dma_map_single()/dmap_unmap_single() will not do flush or invalidate. > My bad, I thought dma_sync*() calls did it. Shimoda-san do you see any platform restrictions while using streaming DMA api instead of coherent memory. Note I tried this enabling/disabling ipmmu too but the results are the same. > Did you try to probe the failure further by comparing the hexdumps? Where does > the mismatch happen? > I shall dump the memory and check the values, but basically crc is failing. > > > >>> > >>> Could you please confirm with streaming DMA api without DMA (-d) > >>> option for large buffers read/write/copy > >>> still passes for you. > >> > >> root@j7-evm:~# ./pcitest -r > >> READ ( 102400 bytes): OKAY > >> root@j7-evm:~# ./pcitest -r -s 1024000 > >> READ (1024000 bytes): OKAY > >> root@j7-evm:~# ./pcitest -w -s 1024000 > >> WRITE (1024000 bytes): OKAY > >> root@j7-evm:~# ./pcitest -c -s 1024000 > >> COPY (1024000 bytes): OKAY > >> root@j7-evm:~# ./pcitest -c -s 10240000 > >> COPY (10240000 bytes): OKAY > >> root@j7-evm:~# ./pcitest -r -s 10240000 > >> READ (10240000 bytes): OKAY > >> root@j7-evm:~# ./pcitest -w -s 10240000 > >> WRITE (10240000 bytes): OKAY > > > > Thank you for testing is this on Jacinto ? > > > >>> > >>> Although I am not sure why adding GFP_KERNEL | GFP_DMA flag for > >>> kzalloc on my platform fixes everything. > >> > >> Which host do you use? If this is only a host side limitation, you could try > >> using a different host. > >> > > I am trying this on Renesas RZ/G2N as host and RZ/G2E as an endpoint. > > ATM I can only test this on > > Renesas platforms only and all of them have same PCIe controller :( > > Does the host controller work well with other standard PCIe cards (NVMe, USB > etc.,)? It does work Ethernet/USB if I am not wrong there is a issue with NVMe. > > > > How about adding flags as part of driver data and defaulting it GFP_KERNEL ? > > Nope. Not before we clearly understand the reason for the failure. > I shall do further debugging. Cheers, --Prabhakar > Thanks > Kishon > > > > > Cheers, > > --Prabhakar > > > >> Thanks > >> Kishon > >> > >>> > >>> Cheers, > >>> --Prabhakar > >>> > >>> > >>>> Cheers, > >>>> --Prabhakar > >>>> > >>>>> Cheers, > >>>>> --Prabhakar > >>>>> > >>>>>> Thanks > >>>>>> Kishon > >>>>>> > >>>>>>> root@hihope-rzg2m:~# pcitest -r > >>>>>>> [ 53.354830] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > >>>>>>> kzalloc:ffff0004b4ae0000 dma:7e9e2000 align:ffff0004b4ae0000 > >>>>>>> READ ( 102400 bytes): NOT OKAY > >>>>>>> root@hihope-rzg2m:~# pcitest -r > >>>>>>> [ 55.307236] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > >>>>>>> kzalloc:ffff0004b4ae0000 dma:7ea04000 align:ffff0004b4ae0000 > >>>>>>> READ ( 102400 bytes): NOT OKAY > >>>>>>> root@hihope-rzg2m:~# pcitest -r > >>>>>>> [ 57.098626] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > >>>>>>> kzalloc:ffff0004b4ae0000 dma:7ea23000 align:ffff0004b4ae0000 > >>>>>>> READ ( 102400 bytes): NOT OKAY > >>>>>>> > >>>>>>> # GFP_KERNEL | GFP_DMA > >>>>>>> > >>>>>>> root@hihope-rzg2m:~# pcitest -r -s 1024001 > >>>>>>> [ 174.562071] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > >>>>>>> kzalloc:ffff00003b900000 dma:7b900000 align:ffff00003b900000 > >>>>>>> READ (1024001 bytes): OKAY > >>>>>>> root@hihope-rzg2m:~# pcitest -r -s 16384 > >>>>>>> [ 186.629347] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > >>>>>>> kzalloc:ffff00003b848000 dma:7b848000 align:ffff00003b848000 > >>>>>>> READ ( 16384 bytes): OKAY > >>>>>>> root@hihope-rzg2m:~# pcitest -r -s 8192 > >>>>>>> [ 190.578335] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > >>>>>>> kzalloc:ffff00003b840000 dma:7b840000 align:ffff00003b840000 > >>>>>>> READ ( 8192 bytes): OKAY > >>>>>>> root@hihope-rzg2m:~# pcitest -r -s 128 > >>>>>>> [ 199.428021] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > >>>>>>> kzalloc:ffff00003b800000 dma:7b800000 align:ffff00003b800000 > >>>>>>> READ ( 128 bytes): OKAY > >>>>>>> root@hihope-rzg2m:~# > >>>>>>> > >>>>>>> Cheers, > >>>>>>> --Prabhakar > >>>>>>> > >>>>>>>> Thanks > >>>>>>>> Kishon
