[PATCHv4 10/14] cmd: cpu: add release subcommand

[Simon Glass]

Hi Zhiqiang,

On Wed, 31 Jul 2024 at 20:37, Z.Q. Hou <zhiqiang.hou at nxp.com> wrote:
>
> Hi Simon,
>
> > -----Original Message-----
> > From: Simon Glass <sjg at chromium.org>
> > Sent: Wednesday, July 31, 2024 10:39 PM
> > To: Z.Q. Hou <zhiqiang.hou at nxp.com>
> > Cc: u-boot at lists.denx.de; trini at konsulko.com; Peng Fan
> > <peng.fan at nxp.com>; festevam at gmail.com; marex at denx.de;
> > lukma at denx.de; seanga2 at gmail.com; xypron.glpk at gmx.de
> > Subject: Re: [PATCHv4 10/14] cmd: cpu: add release subcommand
> >
> > Hi Zhiqiang,
> >
> > On Tue, 30 Jul 2024 at 01:09, Zhiqiang Hou <Zhiqiang.Hou at nxp.com> wrote:
> > >
> > > From: Hou Zhiqiang <Zhiqiang.Hou at nxp.com>
> > >
> > > Add a new subcommand 'release' to bring up a core to run baremetal and
> > > RTOS applications.
> > >
> > > For example on i.MX8M Plus EVK, release the LAST core to run a RTOS
> > > application, passing the sequence number of the CPU core to release,
> > > here it is 3:
> > >     u-boot=> cpu list
> > >       0: cpu at 0      NXP i.MX8MP Rev1.1 A53 at 1200 MHz at 31C
> > >       1: cpu at 1      NXP i.MX8MP Rev1.1 A53 at 1200 MHz at 30C
> > >       2: cpu at 2      NXP i.MX8MP Rev1.1 A53 at 1200 MHz at 31C
> > >       3: cpu at 3      NXP i.MX8MP Rev1.1 A53 at 1200 MHz at 31C
> > >
> > >     u-boot=> load mmc 1:2 c0000000 /hello_world.bin
> > >     66008 bytes read in 5 ms (12.6 MiB/s)
> > >     u-boot=> dcache flush; icache flush
> > >     u-boot=> cpu release 3 c0000000
> > >     Released CPU core (mpidr: 0x3) to address 0xc0000000
> > >
> > > Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou at nxp.com>
> > > Reviewed-by: Simon Glass <sjg at chromium.org>
> > > ---
> > > V4:
> > >  - Updated the change logs.
> > >
> > >  cmd/cpu.c | 44 ++++++++++++++++++++++++++++++++++++++++++--
> > >  1 file changed, 42 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/cmd/cpu.c b/cmd/cpu.c
> > > index 9e323069b9..2755250756 100644
> > > --- a/cmd/cpu.c
> > > +++ b/cmd/cpu.c
> > > @@ -3,6 +3,7 @@
> > >   * Copyright (c) 2015 Google, Inc
> > >   * Written by Simon Glass <sjg at chromium.org>
> > >   * Copyright (c) 2017 Álvaro Fernández Rojas <noltari at gmail.com>
> > > + * Copyright 2024 NXP
> > >   */
> > >
> > >  #include <command.h>
> > > @@ -18,6 +19,19 @@ static const char
> > *cpu_feature_name[CPU_FEAT_COUNT] = {
> > >         "Device ID",
> > >  };
> > >
> > > +static struct udevice *cpu_find_device(unsigned long cpu_id) {
> > > +       struct udevice *dev;
> > > +
> > > +       for (uclass_first_device(UCLASS_CPU, &dev); dev;
> > > +            uclass_next_device(&dev)) {
> > > +               if (cpu_id == dev_seq(dev))
> > > +                       return dev;
> > > +       }
> > > +
> > > +       return NULL;
> > > +}
> > > +
> > >  static int print_cpu_list(bool detail)  {
> > >         struct udevice *dev;
> > > @@ -82,10 +96,36 @@ static int do_cpu_detail(struct cmd_tbl *cmdtp, int
> > flag, int argc,
> > >         return 0;
> > >  }
> > >
> > > +static int do_cpu_release(struct cmd_tbl *cmdtp, int flag, int argc,
> > > +                         char *const argv[]) {
> > > +       struct udevice *dev;
> > > +       unsigned long cpu_id;
> > > +       unsigned long long boot_addr;
> > > +
> > > +       if (argc != 3)
> > > +               return CMD_RET_USAGE;
> > > +
> > > +       cpu_id = dectoul(argv[1], NULL);
> >
> > I just noticed this...normally we use hex for parameters.
>
> Yes, but the <core ID> is from the CPU device sequence number listed by the 'cpu list', which is printed in dec. So I think use dec parameter here is reasonable.

We will have devices with hundreds of CPUs so decimal is probably
going to bite us. U-Boot uses hex for most values.

Anyway, let's worry about it later. What you have is fine.

Regards,
Simon