On Thu, Feb 17, 2022 at 09:42:08AM +0100, Thomas Zimmermann wrote:
Hi Am 16.02.22 um 18:41 schrieb Lucas De Marchi:First the simplest ones: - iosys_map_memset(): when abstracting system and I/O memory, just like the memcpy() use case, memset() also has dedicated functions to be called for using IO memory. - iosys_map_memcpy_from(): we may need to copy data from I/O memory, not only to. In certain situations it's useful to be able to read or write to an offset that is calculated by having the memory layout given by a struct declaration. Usually we are going to read/write a u8, u16, u32 or u64. As a pre-requisite for the implementation, add iosys_map_memcpy_from() to be the equivalent of iosys_map_memcpy_to(), but in the other direction. Then add 2 pairs of macros: - iosys_map_rd() / iosys_map_wr() - iosys_map_rd_field() / iosys_map_wr_field() The first pair takes the C-type and offset to read/write. The second pair uses a struct describing the layout of the mapping in order to calculate the offset and size being read/written. We could use readb, readw, readl, readq and the write* counterparts, however due to alignment issues this may not work on all architectures. If alignment needs to be checked to call the right function, it's not possible to decide at compile-time which function to call: so just leave the decision to the memcpy function that will do exactly that. Finally, in order to use the above macros with a map derived from another, add another initializer: IOSYS_MAP_INIT_OFFSET(). v2: - Rework IOSYS_MAP_INIT_OFFSET() so it doesn't rely on aliasing rules within the union - Add offset to both iosys_map_rd_field() and iosys_map_wr_field() to allow the struct itself to be at an offset from the mapping - Add documentation to iosys_map_rd_field() with example and expected memory layout v3: - Drop kernel.h include as it's not needed anymore Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx> Cc: Christian König <christian.koenig@xxxxxxx> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx> Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Signed-off-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx> Reviewed-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> Reviewed-by: Matt Atwood <matthew.s.atwood@xxxxxxxxx>Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Thanks. I applied the first 2 patches to drm-intel-next. The rest can't be applied as there are conflicts between drm-intel-next and drm-intel-gt-next. I should have merged the rename to drm-intel-gt-next since the guc patches need to be applied there. I guess the rest will have to wait some tree propagation. Lucas De Marchi
