On Wed, Feb 28, 2024 at 09:46:51AM +0100, Stefan Kerkmann wrote: > Hi Sascha, > > On 27.02.24 09:44, Sascha Hauer wrote: > > On Mon, Feb 26, 2024 at 03:40:23PM +0100, Stefan Kerkmann wrote: > > > Instead of passing in configuration parameters at runtime we can utilize > > > the `cpu_is_mx8xyz` macro family to determine which bits should be set. > > > > > > As the tzasc driver is imx specific, all functions are prefixed with > > > `imx8m_` as well. > > > > > > Signed-off-by: Stefan Kerkmann <s.kerkmann@xxxxxxxxxxxxxx> > > > --- > > > arch/arm/mach-imx/atf.c | 8 ++++---- > > > arch/arm/mach-imx/imx8m.c | 2 +- > > > arch/arm/mach-imx/tzasc.c | 25 +++++-------------------- > > > include/mach/imx/tzasc.h | 8 ++------ > > > 4 files changed, 12 insertions(+), 31 deletions(-) > > > > > > diff --git a/arch/arm/mach-imx/atf.c b/arch/arm/mach-imx/atf.c > > > index e8060ebd95..9cbc38ef11 100644 > > > --- a/arch/arm/mach-imx/atf.c > > > +++ b/arch/arm/mach-imx/atf.c > > > @@ -158,7 +158,7 @@ __noreturn void __imx8mm_load_and_start_image_via_tfa(void *bl33) > > > size_t bl32_size; > > > void *bl32_image; > > > - imx8mm_tzc380_init(); > > > + imx8m_tzc380_init(); > > > > I am not so sure about this patch. So far the whole PBL is coded in the > > way that we inherently know the SoC type from the code path chosen. > > > > This patch changes this. It doesn't really matter for this patch, but it > > sends a sign how we want to solve this in future. > > Let's see if I can persuade you that this is a good thing :-). > > > One implication of this patch is that cpu_is_mx() is a runtime decision, > > so code paths behind an unused cpu_is_mx() can't be discarded anymore. > > My argument here is that the overhead in code size is probably neglect able > in most cases, as most of the code paths are still discarded: > > 1. If there is only one ARCH selected e.g., `CONFIG_ARCH_IMX8MM` the > `cpu_is_mx8mm()` macro is still evaluated at compile time. As the > `__imx_cpu_type` variable is only assigned and never read it can be stripped > away by the compiler/linker and become a nop. > > 2. Runtime evaluation is only selected if a second arch is enabled for the > build. But even then the runtime decision is only compiled in for the two > selected arches, as all other `cpu_is_xyz` macros still evaluate at compile > time to false. So code paths that don't touch the selected arches will still > be stripped. > > > Another thing is that the usage of cpu_is() has the tendency to lead to > > cascades of if (cpu_is_x() || cpu_is_y() || cpu_is_z()) which is not > > paticularly nice to read. > > > > That is arguably subjective :-). > > For me as a developer that is new to barebox, it was confusing to find two > different styles of arch dependent code. I prefer the `cpu_is_xyz` style > approach which is used in barebox proper much more. > > In the case of the TZC380 driver the pseudo (as they are probably optimized > away) runtime arguments to the init functions seem unnecessarily > complicated, as does the approach to define aliases to the same function for > all arches. The if style is clearer in intend as it keeps the distinction > between the arches local to the parts that are actually different. Which is > straight forward to read IMHO. Ok, let's see where this brings us. Can you rebase on current next? Some of the code you are modifying went to drivers/soc/imx/soc-imx8m.c recently. Sascha -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
