target/linux/bmips/patches-5.10/040-v5.13-mips-smp-bmips-fix-CPU-mappings.patch

   1 From c0f41a0dac1f3db6c40aabc0f3ac8868709ba6a6 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?=C3=81lvaro=20Fern=C3=A1ndez=20Rojas?= <noltari@gmail.com>
   3 Date: Wed, 24 Feb 2021 08:33:36 +0100
   4 Subject: [PATCH] mips: smp-bmips: fix CPU mappings
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 When booting bmips with SMP enabled on a BCM6358 running on CPU #1 instead of
  10 CPU #0, the current CPU mapping code produces the following:
  11 - smp_processor_id(): 0
  12 - cpu_logical_map(0): 1
  13 - cpu_number_map(0): 1
  14
  15 This is because SMP isn't supported on BCM6358 since it has a shared TLB, so
  16 it is disabled and max_cpus is decreased from 2 to 1.
  17
  18 Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
  19 Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
  20 Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
  21 ---
  22  arch/mips/kernel/smp-bmips.c | 27 +++++++++++++++++----------
  23  1 file changed, 17 insertions(+), 10 deletions(-)
  24
  25 --- a/arch/mips/kernel/smp-bmips.c
  26 +++ b/arch/mips/kernel/smp-bmips.c
  27 @@ -134,17 +134,24 @@ static void __init bmips_smp_setup(void)
  28         if (!board_ebase_setup)
  29                 board_ebase_setup = &bmips_ebase_setup;
  30
  31 -       __cpu_number_map[boot_cpu] = 0;
  32 -       __cpu_logical_map[0] = boot_cpu;
  33 +       if (max_cpus > 1) {
  34 +               __cpu_number_map[boot_cpu] = 0;
  35 +               __cpu_logical_map[0] = boot_cpu;
  36
  37 -       for (i = 0; i < max_cpus; i++) {
  38 -               if (i != boot_cpu) {
  39 -                       __cpu_number_map[i] = cpu;
  40 -                       __cpu_logical_map[cpu] = i;
  41 -                       cpu++;
  42 +               for (i = 0; i < max_cpus; i++) {
  43 +                       if (i != boot_cpu) {
  44 +                               __cpu_number_map[i] = cpu;
  45 +                               __cpu_logical_map[cpu] = i;
  46 +                               cpu++;
  47 +                       }
  48 +                       set_cpu_possible(i, 1);
  49 +                       set_cpu_present(i, 1);
  50                 }
  51 -               set_cpu_possible(i, 1);
  52 -               set_cpu_present(i, 1);
  53 +       } else {
  54 +               __cpu_number_map[0] = boot_cpu;
  55 +               __cpu_logical_map[0] = 0;
  56 +               set_cpu_possible(0, 1);
  57 +               set_cpu_present(0, 1);
  58         }
  59  }
  60