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| author | Conor Dooley <conor.dooley@microchip.com> | 2022-10-19 15:53:03 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-10-30 11:41:19 +0300 |
| commit | 79c3482fbe20e39630b0f95e1ffeb846aa945c41 (patch) | |
| tree | f7b601608661f211c6006dde35892f1f727577de /arch/riscv | |
| parent | a6e770733dc4ce616ff77f43f50507fa2034ff49 (diff) | |
| download | linux-79c3482fbe20e39630b0f95e1ffeb846aa945c41.tar.xz | |
riscv: topology: fix default topology reporting
commit fbd92809997a391f28075f1c8b5ee314c225557c upstream.
RISC-V has no sane defaults to fall back on where there is no cpu-map
in the devicetree.
Without sane defaults, the package, core and thread IDs are all set to
-1. This causes user-visible inaccuracies for tools like hwloc/lstopo
which rely on the sysfs cpu topology files to detect a system's
topology.
On a PolarFire SoC, which should have 4 harts with a thread each,
lstopo currently reports:
Machine (793MB total)
Package L#0
NUMANode L#0 (P#0 793MB)
Core L#0
L1d L#0 (32KB) + L1i L#0 (32KB) + PU L#0 (P#0)
L1d L#1 (32KB) + L1i L#1 (32KB) + PU L#1 (P#1)
L1d L#2 (32KB) + L1i L#2 (32KB) + PU L#2 (P#2)
L1d L#3 (32KB) + L1i L#3 (32KB) + PU L#3 (P#3)
Adding calls to store_cpu_topology() in {boot,smp} hart bringup code
results in the correct topolgy being reported:
Machine (793MB total)
Package L#0
NUMANode L#0 (P#0 793MB)
L1d L#0 (32KB) + L1i L#0 (32KB) + Core L#0 + PU L#0 (P#0)
L1d L#1 (32KB) + L1i L#1 (32KB) + Core L#1 + PU L#1 (P#1)
L1d L#2 (32KB) + L1i L#2 (32KB) + Core L#2 + PU L#2 (P#2)
L1d L#3 (32KB) + L1i L#3 (32KB) + Core L#3 + PU L#3 (P#3)
CC: stable@vger.kernel.org # 456797da792f: arm64: topology: move store_cpu_topology() to shared code
Fixes: 03f11f03dbfe ("RISC-V: Parse cpu topology during boot.")
Reported-by: Brice Goglin <Brice.Goglin@inria.fr>
Link: https://github.com/open-mpi/hwloc/issues/536
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/riscv')
| -rw-r--r-- | arch/riscv/Kconfig | 2 | ||||
| -rw-r--r-- | arch/riscv/kernel/smpboot.c | 4 |
2 files changed, 4 insertions, 2 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 1b894c327578..557c4a8c4087 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -35,7 +35,7 @@ config RISCV select CLINT_TIMER if !MMU select COMMON_CLK select EDAC_SUPPORT - select GENERIC_ARCH_TOPOLOGY if SMP + select GENERIC_ARCH_TOPOLOGY select GENERIC_ATOMIC64 if !64BIT select GENERIC_CLOCKEVENTS select GENERIC_EARLY_IOREMAP diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index 0b04e0eae3ab..0e0aed380e28 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -46,6 +46,8 @@ void __init smp_prepare_cpus(unsigned int max_cpus) int cpuid; int ret; + store_cpu_topology(smp_processor_id()); + /* This covers non-smp usecase mandated by "nosmp" option */ if (max_cpus == 0) return; @@ -152,8 +154,8 @@ asmlinkage __visible void smp_callin(void) mmgrab(mm); current->active_mm = mm; + store_cpu_topology(curr_cpuid); notify_cpu_starting(curr_cpuid); - update_siblings_masks(curr_cpuid); set_cpu_online(curr_cpuid, 1); /* |