On 09/08/2016 01:21 PM, Paul Burton wrote:
On 08/09/16 11:47, Marek Vasut wrote:
On 09/08/2016 12:36 PM, Paul Burton wrote:
On 08/09/16 11:02, Marek Vasut wrote:
On 09/07/2016 07:48 PM, Paul Burton wrote:
Add an implementation of arch_cpu_init that covers all MIPS boards, in preparation for performing various pieces of initialisation there in later patches.
In order to allow the ath79 code to continue performing initialisation at this point in the boot, it's converted to use a new mach_cpu_init function which is called from arch_cpu_init.
Signed-off-by: Paul Burton paul.burton@imgtec.com
[...]
Hi!
diff --git a/arch/mips/include/asm/u-boot-mips.h b/arch/mips/include/asm/u-boot-mips.h index 1f527bb..0eaf32b 100644 --- a/arch/mips/include/asm/u-boot-mips.h +++ b/arch/mips/include/asm/u-boot-mips.h @@ -5,4 +5,16 @@ #ifndef _U_BOOT_MIPS_H_ #define _U_BOOT_MIPS_H_
+/**
- mach_cpu_init() - Perform SoC/machine-specific CPU initialisation
- This is called from arch_cpu_init() to allow for SoC/machine-level code to
- perform any CPU initialisation it may require.
Just call this function from arch_cpu_init() in various places instead of replacing arch_cpu_init() with it all over the place. Also rename it to arch_cpu_init_common() to make it more obvious what this does .
Hi Marek,
Hi,
That's "backwards" compared with what this code actually does - arch_cpu_init becomes the common function (ie. is arch-wide as in the patch subject) and mach_cpu_init is for use by machines/SoCs - ie. code under arch/mips/mach-*.
For machines, we already have board_cpu_init() , for SoCs we have arch_cpu_init() . Reading through the patchset, I understand the purpose, but then the content of mach_cpu_init() looks like some common arch init bit to me.
Hi Marek,
The content of the only implementation of mach_cpu_init is some ath79-specific chip ID stuff. I'm not sure how you think that's "common arch init"?
Right now without this patch you're right - arch_cpu_init is used by SoCs (well, one SoC - ath79). This patch changes that so that arch_cpu_init is used by the arch code & mach_cpu_init is used by the SoC/machine code under arch/mips/mach-*. That seems like the most logical way to handle it to me.
It also introduces discrepancy with ARM and other architectures though.
I get that arch_cpu_init is also used by SoCs on some other architectures (arm & x86 seemingly), but not on all - there's precedent for an arch-wide implementation in arc, avr32, blackfin, nios2 or xtensa.
Most of which are dead/unmaintained though.
Seems like this might need some further cleanup/clarification then.
- */
+#ifdef CONFIG_MACH_CPU_INIT +void mach_cpu_init(void); +#else +static inline void mach_cpu_init(void) {}
Implement this as __weak int and you can nuke the ifdefery .
I could make it weak, but then we don't let the compiler optimise it out entirely for builds that don't need it (ie. everything except ath79).
Did you try it ?
I didn't, but the compiler will have to emit the call as it won't be known whether there's an implementation of the function until link time so it will obviously have a small cost (unless LTO is used). Having said that I see the U-Boot wiki seems to indicate that weak is preferred so I'm ok with changing it.
btw if you want to go ahead with adding the mach_cpu_init(), you might want to consider adding it into the board_f.c initcalls , so other arches can convert to it.