Re: [PATCH] testsuite/spcache01: Clear allocated coherent cache memory
On 20/10/21 2:46 am, Christian MAUDERER wrote: > Am 19.10.21 um 16:48 schrieb Sebastian Huber: >> >> >> On 18/10/2021 23:08, Chris Johns wrote: >>> On 18/10/21 8:37 pm, Sebastian Huber wrote: On 18/10/2021 09:53, Chris Johns wrote: > On 18/10/21 4:50 pm, Sebastian Huber wrote: >> On 18/10/2021 07:19,chr...@rtems.org wrote: >>> From: Chris Johns >>> >>> - Coherent cache memory is used in libbsd for things like descriptors >>> and it optionally clears the memory on allocation. Test is works. >> There is no guarantee that memset() and memcpy() work with cache coherent >> memory. Such memory areas may disallow misaligned access for example. > That seems reasonable however this change about testing the implicit > requirements we have that memset works. LibBSD requires memset works ... > > https://git.rtems.org/rtems-libbsd/tree/rtemsbsd/rtems/rtems-kernel-bus-dma.c?h=6-freebsd-12#n260 > > Using memset() here could be a bug in libbsd. >>> Yes, I also think so. >>> >>> But what is a suitable mechanism to make sure the arch or BSP handle it >>> correctly? Maybe a clear routine in libbsd using the bus space API? That >>> interface has to work or the drivers will not work. >> >> I think we had similar issues on another BSP. Christian, do you remember how >> we solved this? >> > > I remember mainly problems with copying memory. I think the last time it > resulted in an ugly "copy_from/to_io" function on the atsam: > > https://git.rtems.org/rtems/tree/bsps/arm/atsam/start/iocopy.c > Thanks. > The bus_space_* functions should work. Only problem is that a valid > bus_space_tag is missing in this context. I think x86 uses it. I think for all > other platforms it is unused. I used the direct methods because it is internal and I think it is safe to assume this is a linear address being returned from the allocator? I have posted a patch which is working on the Versal. It is not optimized and does not attempt to detect alignments to use larger word sizes for faster clears. The amount of memory being allocated is not large. Chris ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
Re: [PATCH] testsuite/spcache01: Clear allocated coherent cache memory
Am 19.10.21 um 16:48 schrieb Sebastian Huber: On 18/10/2021 23:08, Chris Johns wrote: On 18/10/21 8:37 pm, Sebastian Huber wrote: On 18/10/2021 09:53, Chris Johns wrote: On 18/10/21 4:50 pm, Sebastian Huber wrote: On 18/10/2021 07:19,chr...@rtems.org wrote: From: Chris Johns - Coherent cache memory is used in libbsd for things like descriptors and it optionally clears the memory on allocation. Test is works. There is no guarantee that memset() and memcpy() work with cache coherent memory. Such memory areas may disallow misaligned access for example. That seems reasonable however this change about testing the implicit requirements we have that memset works. LibBSD requires memset works ... https://git.rtems.org/rtems-libbsd/tree/rtemsbsd/rtems/rtems-kernel-bus-dma.c?h=6-freebsd-12#n260 Using memset() here could be a bug in libbsd. Yes, I also think so. But what is a suitable mechanism to make sure the arch or BSP handle it correctly? Maybe a clear routine in libbsd using the bus space API? That interface has to work or the drivers will not work. I think we had similar issues on another BSP. Christian, do you remember how we solved this? I remember mainly problems with copying memory. I think the last time it resulted in an ugly "copy_from/to_io" function on the atsam: https://git.rtems.org/rtems/tree/bsps/arm/atsam/start/iocopy.c The bus_space_* functions should work. Only problem is that a valid bus_space_tag is missing in this context. I think x86 uses it. I think for all other platforms it is unused. Best regards Christian -- embedded brains GmbH Herr Christian MAUDERER Dornierstr. 4 82178 Puchheim Germany email: christian.maude...@embedded-brains.de phone: +49-89-18 94 741 - 18 fax: +49-89-18 94 741 - 08 Registergericht: Amtsgericht München Registernummer: HRB 157899 Vertretungsberechtigte Geschäftsführer: Peter Rasmussen, Thomas Dörfler Unsere Datenschutzerklärung finden Sie hier: https://embedded-brains.de/datenschutzerklaerung/ ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
Re: [PATCH] testsuite/spcache01: Clear allocated coherent cache memory
On 18/10/2021 23:08, Chris Johns wrote: On 18/10/21 8:37 pm, Sebastian Huber wrote: On 18/10/2021 09:53, Chris Johns wrote: On 18/10/21 4:50 pm, Sebastian Huber wrote: On 18/10/2021 07:19,chr...@rtems.org wrote: From: Chris Johns - Coherent cache memory is used in libbsd for things like descriptors and it optionally clears the memory on allocation. Test is works. There is no guarantee that memset() and memcpy() work with cache coherent memory. Such memory areas may disallow misaligned access for example. That seems reasonable however this change about testing the implicit requirements we have that memset works. LibBSD requires memset works ... https://git.rtems.org/rtems-libbsd/tree/rtemsbsd/rtems/rtems-kernel-bus-dma.c?h=6-freebsd-12#n260 Using memset() here could be a bug in libbsd. Yes, I also think so. But what is a suitable mechanism to make sure the arch or BSP handle it correctly? Maybe a clear routine in libbsd using the bus space API? That interface has to work or the drivers will not work. I think we had similar issues on another BSP. Christian, do you remember how we solved this? -- embedded brains GmbH Herr Sebastian HUBER Dornierstr. 4 82178 Puchheim Germany email: sebastian.hu...@embedded-brains.de phone: +49-89-18 94 741 - 16 fax: +49-89-18 94 741 - 08 Registergericht: Amtsgericht München Registernummer: HRB 157899 Vertretungsberechtigte Geschäftsführer: Peter Rasmussen, Thomas Dörfler Unsere Datenschutzerklärung finden Sie hier: https://embedded-brains.de/datenschutzerklaerung/ ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
Re: [PATCH] testsuite/spcache01: Clear allocated coherent cache memory
On 18/10/21 8:37 pm, Sebastian Huber wrote: > On 18/10/2021 09:53, Chris Johns wrote: >> On 18/10/21 4:50 pm, Sebastian Huber wrote: >>> On 18/10/2021 07:19,chr...@rtems.org wrote: From: Chris Johns - Coherent cache memory is used in libbsd for things like descriptors and it optionally clears the memory on allocation. Test is works. >>> There is no guarantee that memset() and memcpy() work with cache coherent >>> memory. Such memory areas may disallow misaligned access for example. >> That seems reasonable however this change about testing the implicit >> requirements we have that memset works. LibBSD requires memset works ... >> >> https://git.rtems.org/rtems-libbsd/tree/rtemsbsd/rtems/rtems-kernel-bus-dma.c?h=6-freebsd-12#n260 >> > > Using memset() here could be a bug in libbsd. Yes, I also think so. But what is a suitable mechanism to make sure the arch or BSP handle it correctly? Maybe a clear routine in libbsd using the bus space API? That interface has to work or the drivers will not work. Chris ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
Re: [PATCH] testsuite/spcache01: Clear allocated coherent cache memory
On 18/10/2021 09:53, Chris Johns wrote: On 18/10/21 4:50 pm, Sebastian Huber wrote: On 18/10/2021 07:19,chr...@rtems.org wrote: From: Chris Johns - Coherent cache memory is used in libbsd for things like descriptors and it optionally clears the memory on allocation. Test is works. There is no guarantee that memset() and memcpy() work with cache coherent memory. Such memory areas may disallow misaligned access for example. That seems reasonable however this change about testing the implicit requirements we have that memset works. LibBSD requires memset works ... https://git.rtems.org/rtems-libbsd/tree/rtemsbsd/rtems/rtems-kernel-bus-dma.c?h=6-freebsd-12#n260 Using memset() here could be a bug in libbsd. -- embedded brains GmbH Herr Sebastian HUBER Dornierstr. 4 82178 Puchheim Germany email: sebastian.hu...@embedded-brains.de phone: +49-89-18 94 741 - 16 fax: +49-89-18 94 741 - 08 Registergericht: Amtsgericht München Registernummer: HRB 157899 Vertretungsberechtigte Geschäftsführer: Peter Rasmussen, Thomas Dörfler Unsere Datenschutzerklärung finden Sie hier: https://embedded-brains.de/datenschutzerklaerung/ ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
Re: [PATCH] testsuite/spcache01: Clear allocated coherent cache memory
On 18/10/21 4:50 pm, Sebastian Huber wrote: > On 18/10/2021 07:19, chr...@rtems.org wrote: >> From: Chris Johns >> >> - Coherent cache memory is used in libbsd for things like descriptors >> and it optionally clears the memory on allocation. Test is works. > > There is no guarantee that memset() and memcpy() work with cache coherent > memory. Such memory areas may disallow misaligned access for example. That seems reasonable however this change about testing the implicit requirements we have that memset works. LibBSD requires memset works ... https://git.rtems.org/rtems-libbsd/tree/rtemsbsd/rtems/rtems-kernel-bus-dma.c?h=6-freebsd-12#n260 Chris ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
Re: [PATCH] testsuite/spcache01: Clear allocated coherent cache memory
On 18/10/2021 07:19, chr...@rtems.org wrote: From: Chris Johns - Coherent cache memory is used in libbsd for things like descriptors and it optionally clears the memory on allocation. Test is works. There is no guarantee that memset() and memcpy() work with cache coherent memory. Such memory areas may disallow misaligned access for example. -- embedded brains GmbH Herr Sebastian HUBER Dornierstr. 4 82178 Puchheim Germany email: sebastian.hu...@embedded-brains.de phone: +49-89-18 94 741 - 16 fax: +49-89-18 94 741 - 08 Registergericht: Amtsgericht München Registernummer: HRB 157899 Vertretungsberechtigte Geschäftsführer: Peter Rasmussen, Thomas Dörfler Unsere Datenschutzerklärung finden Sie hier: https://embedded-brains.de/datenschutzerklaerung/ ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
