sparc64: Fix number of online CPUs
commit 98937707fea8375e8acea0aaa0b68a956dd52719 upstream.
Nick Bowler reported:
When using newer kernels on my Ultra 60 with dual 450MHz UltraSPARC-II
CPUs, I noticed that only CPU 0 comes up, while older kernels (including
4.7) are working fine with both CPUs.
I bisected the failure to this commit:
9b2f753ec23710aa32c0d837d2499db92fe9115b is the first bad commit
commit 9b2f753ec23710aa32c0d837d2499db92fe9115b
Author: Atish Patra <atish.patra@oracle.com>
Date: Thu Sep 15 14:54:40 2016 -0600
sparc64: Fix cpu_possible_mask if nr_cpus is set
This is a small change that reverts very easily on top of 5.18: there is
just one trivial conflict. Once reverted, both CPUs work again.
Maybe this is related to the fact that the CPUs on this system are
numbered CPU0 and CPU2 (there is no CPU1)?
The current code that adjust cpu_possible based on nr_cpu_ids do not
take into account that CPU's may not come one after each other.
Move the chech to the function that setup the cpu_possible mask
so there is no need to adjust it later.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Fixes: 9b2f753ec237 ("sparc64: Fix cpu_possible_mask if nr_cpus is set")
Reported-by: Nick Bowler <nbowler@draconx.ca>
Tested-by: Nick Bowler <nbowler@draconx.ca>
Link: https://lore.kernel.org/sparclinux/20201009161924.c8f031c079dd852941307870@gmx.de/
Link: https://lore.kernel.org/all/CADyTPEwt=ZNams+1bpMB1F9w_vUdPsGCt92DBQxxq_VtaLoTdw@mail.gmail.com/
Cc: stable@vger.kernel.org # v4.8+
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Atish Patra <atish.patra@oracle.com>
Cc: Bob Picco <bob.picco@oracle.com>
Cc: Vijay Kumar <vijay.ac.kumar@oracle.com>
Cc: David S. Miller <davem@davemloft.net>
Reviewed-by: Andreas Larsson <andreas@gaisler.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20240330-sparc64-warnings-v1-9-37201023ee2f@ravnborg.org
Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 180b2e4c1ba4f6e3e4c52d6664cb019f6eac02f8)
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
diff --git a/arch/sparc/include/asm/smp_64.h b/arch/sparc/include/asm/smp_64.h
index e75783b..16ab904 100644
--- a/arch/sparc/include/asm/smp_64.h
+++ b/arch/sparc/include/asm/smp_64.h
@@ -47,7 +47,6 @@
int hard_smp_processor_id(void);
#define raw_smp_processor_id() (current_thread_info()->cpu)
-void smp_fill_in_cpu_possible_map(void);
void smp_fill_in_sib_core_maps(void);
void cpu_play_dead(void);
@@ -77,7 +76,6 @@
#define smp_fill_in_sib_core_maps() do { } while (0)
#define smp_fetch_global_regs() do { } while (0)
#define smp_fetch_global_pmu() do { } while (0)
-#define smp_fill_in_cpu_possible_map() do { } while (0)
#define smp_init_cpu_poke() do { } while (0)
#define scheduler_poke() do { } while (0)
diff --git a/arch/sparc/kernel/prom_64.c b/arch/sparc/kernel/prom_64.c
index baeaeed..4bc0821 100644
--- a/arch/sparc/kernel/prom_64.c
+++ b/arch/sparc/kernel/prom_64.c
@@ -479,7 +479,9 @@
ncpus_probed++;
#ifdef CONFIG_SMP
set_cpu_present(cpuid, true);
- set_cpu_possible(cpuid, true);
+
+ if (num_possible_cpus() < nr_cpu_ids)
+ set_cpu_possible(cpuid, true);
#endif
return NULL;
}
diff --git a/arch/sparc/kernel/setup_64.c b/arch/sparc/kernel/setup_64.c
index 34f7a53..8210b499 100644
--- a/arch/sparc/kernel/setup_64.c
+++ b/arch/sparc/kernel/setup_64.c
@@ -688,7 +688,6 @@
paging_init();
init_sparc64_elf_hwcap();
- smp_fill_in_cpu_possible_map();
/*
* Once the OF device tree and MDESC have been setup and nr_cpus has
* been parsed, we know the list of possible cpus. Therefore we can
diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c
index 9882505..4d8ffc1 100644
--- a/arch/sparc/kernel/smp_64.c
+++ b/arch/sparc/kernel/smp_64.c
@@ -1213,20 +1213,6 @@
xcall_deliver_impl = hypervisor_xcall_deliver;
}
-void __init smp_fill_in_cpu_possible_map(void)
-{
- int possible_cpus = num_possible_cpus();
- int i;
-
- if (possible_cpus > nr_cpu_ids)
- possible_cpus = nr_cpu_ids;
-
- for (i = 0; i < possible_cpus; i++)
- set_cpu_possible(i, true);
- for (; i < NR_CPUS; i++)
- set_cpu_possible(i, false);
-}
-
void smp_fill_in_sib_core_maps(void)
{
unsigned int i;