6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Huacai Chen chenhuacai@loongson.cn
commit 5056c596c3d1848021a4eaa76ee42f4c05c50346 upstream.
Machines which have more than 8 nodes fail to boot SMP after commit a2ccf46333d7b2cf96 ("LoongArch/smp: Call rcutree_report_cpu_starting() earlier"). Because such machines use tlb-based per-cpu base address rather than dmw-based per-cpu base address, resulting per-cpu variables can only be accessed after tlb_init(). But rcutree_report_cpu_starting() is now called before tlb_init() and accesses per-cpu variables indeed.
Since the original patch want to avoid the lockdep warning caused by page allocation in tlb_init(), we can move rcutree_report_cpu_starting() to tlb_init() where after tlb exception configuration but before page allocation.
Fixes: a2ccf46333d7b2cf96 ("LoongArch/smp: Call rcutree_report_cpu_starting() earlier") Signed-off-by: Huacai Chen chenhuacai@loongson.cn Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/loongarch/kernel/smp.c | 1 - arch/loongarch/mm/tlb.c | 16 ++++++++++------ 2 files changed, 10 insertions(+), 7 deletions(-)
--- a/arch/loongarch/kernel/smp.c +++ b/arch/loongarch/kernel/smp.c @@ -506,7 +506,6 @@ asmlinkage void start_secondary(void) sync_counter(); cpu = raw_smp_processor_id(); set_my_cpu_offset(per_cpu_offset(cpu)); - rcu_cpu_starting(cpu);
cpu_probe(); constant_clockevent_init(); --- a/arch/loongarch/mm/tlb.c +++ b/arch/loongarch/mm/tlb.c @@ -284,12 +284,16 @@ static void setup_tlb_handler(int cpu) set_handler(EXCCODE_TLBNR * VECSIZE, handle_tlb_protect, VECSIZE); set_handler(EXCCODE_TLBNX * VECSIZE, handle_tlb_protect, VECSIZE); set_handler(EXCCODE_TLBPE * VECSIZE, handle_tlb_protect, VECSIZE); - } + } else { + int vec_sz __maybe_unused; + void *addr __maybe_unused; + struct page *page __maybe_unused; + + /* Avoid lockdep warning */ + rcu_cpu_starting(cpu); + #ifdef CONFIG_NUMA - else { - void *addr; - struct page *page; - const int vec_sz = sizeof(exception_handlers); + vec_sz = sizeof(exception_handlers);
if (pcpu_handlers[cpu]) return; @@ -305,8 +309,8 @@ static void setup_tlb_handler(int cpu) csr_write64(pcpu_handlers[cpu], LOONGARCH_CSR_EENTRY); csr_write64(pcpu_handlers[cpu], LOONGARCH_CSR_MERRENTRY); csr_write64(pcpu_handlers[cpu] + 80*VECSIZE, LOONGARCH_CSR_TLBRENTRY); - } #endif + } }
void tlb_init(int cpu)