[U-Boot] [PATCH v2 5/9] riscv: add support for multi-hart systems

[Auer, Lukas]

On Sun, 2019-03-10 at 21:01 +0800, Bin Meng wrote:
> On Wed, Mar 6, 2019 at 6:54 AM Lukas Auer
> <lukas.auer at aisec.fraunhofer.de> wrote:
> > On RISC-V, all harts boot independently. To be able to run on a
> > multi-hart system, U-Boot must be extended with the functionality
> > to
> > manage all harts in the system. All harts entering U-Boot are
> > registered
> > in the available_harts mask stored in global data. A hart lottery
> > system
> > as used in the Linux kernel selects the hart U-Boot runs on. All
> > other
> > harts are halted. U-Boot can delegate functions to them using
> > smp_call_function().
> > 
> > Every hart has a valid pointer to the global data structure and a
> > 8KiB
> > stack by default. The stack size is set with
> > CONFIG_STACK_SIZE_SHIFT.
> > 
> > Signed-off-by: Lukas Auer <lukas.auer at aisec.fraunhofer.de>
> > ---
> > 
> > Changes in v2:
> > - Implement hart lottery to pick main hart to run U-Boot
> > - Remove CONFIG_MAIN_HART as it is not required anymore
> > - Register available harts in the available_harts mask
> > 
> >  arch/riscv/Kconfig           |   4 ++
> >  arch/riscv/cpu/cpu.c         |   9 ++-
> >  arch/riscv/cpu/start.S       | 134
> > ++++++++++++++++++++++++++++++++++-
> >  arch/riscv/include/asm/csr.h |   1 +
> >  arch/riscv/lib/asm-offsets.c |   1 +
> >  5 files changed, 147 insertions(+), 2 deletions(-)
> > 
> 
> Looks quite good!
> 

Thank you and thanks for testing and reviewing the series!

Lukas