From: Pierre Gondois pierre.gondois@arm.com
fetch_cache_info() tries to get the number of cache leaves/levels for each CPU in order to pre-allocate memory for cacheinfo struct. Allocating this memory later triggers a: 'BUG: sleeping function called from invalid context' in PREEMPT_RT kernels.
If there is no cache related information available in DT or ACPI, fetch_cache_info() fails and an error message is printed: 'Early cacheinfo failed, ret = ...'
Not having cache information should be a valid configuration. Remove the error message if fetch_cache_info() fails with -ENOENT.
Suggested-by: Conor Dooley conor.dooley@microchip.com Link: https://lore.kernel.org/all/20230404-hatred-swimmer-6fecdf33b57a@spud/ Signed-off-by: Pierre Gondois pierre.gondois@arm.com Reviewed-by: Conor Dooley conor.dooley@microchip.com Link: https://lore.kernel.org/r/20230414081453.244787-4-pierre.gondois@arm.com Signed-off-by: Sudeep Holla sudeep.holla@arm.com --- drivers/base/arch_topology.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index 147fb7d4af96..b741b5ba82bd 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -843,10 +843,11 @@ void __init init_cpu_topology(void)
for_each_possible_cpu(cpu) { ret = fetch_cache_info(cpu); - if (ret) { + if (!ret) + continue; + else if (ret != -ENOENT) pr_err("Early cacheinfo failed, ret = %d\n", ret); - break; - } + return; } }