[RFC PATCH 1/2] Introduce coroutines framework

[Michal Simek]

On 1/20/25 14:50, Jerome Forissier wrote:
> Adds the COROUTINES Kconfig symbol which introduces a new internal API
> for coroutines support. As explained in the Kconfig file, this is meant
> to provide some kind of cooperative multi-tasking with the goal to
> improve performance by overlapping lengthy operations.
> 
> The API as well as the implementation is very much inspired from libaco
> [1]. The reference implementation is simplified to remove all things
> not needed in U-Boot, the coding style is updated, and the aco_ prefix
> is replaced by co_.
> 
> I believe the stack handling could be simplified: the stack of the main
> coroutine could probably probably be used by the secondary coroutines
> instead of allocating a new stack dynamically.
> 
> Only i386, x86_64 and aarch64 are supported at the moment. Other
> architectures need to provide a _co_switch() function in assembly.
> 
> Only aarch64 has been tested.

I can't see the reason why to keep x86 around if it is not tested.

Licenses should be cleared for all files.

Also I think this mostly should target full u-boot and not really TPL/SPL as of 
today.

I have applied this patch to measure time difference on kv260 and kd240 and 
pretty much the time is the same.

diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c
index 94160f4bd86c..18d2260b8c11 100644
--- a/lib/efi_loader/efi_setup.c
+++ b/lib/efi_loader/efi_setup.c
@@ -258,6 +258,7 @@ extern int udelay_yield;
  efi_status_t efi_init_obj_list(void)
  {
         efi_status_t ret = EFI_SUCCESS;
+       ulong t0, t1;
  #if CONFIG_IS_ENABLED(COROUTINES)
         struct co_stack *stk = NULL;
         struct co *main_co = NULL;
@@ -272,6 +273,7 @@ efi_status_t efi_init_obj_list(void)
         /* Set up console modes */
         efi_setup_console_size();

+       t0 = timer_get_us();
  #if CONFIG_IS_ENABLED(COROUTINES)
         main_co = co_create(NULL, NULL, 0, NULL, NULL);
         if (!main_co) {
@@ -333,6 +335,9 @@ efi_status_t efi_init_obj_list(void)
                         efi_obj_list_initialized = ret;
         }
  #endif
+       t1 = timer_get_us();
+
+       printf("time counted %ld\n", t1 - t0);

         /* Initialize variable services */
         ret = efi_init_variables();

Please correct me if you have measured it differently.

Thanks,
Michal