The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 5056c596c3d1848021a4eaa76ee42f4c05c50346 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024012912-yahoo-patchwork-d338@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

5056c596c3d1 ("LoongArch/smp: Call rcutree_report_cpu_starting() at tlb_init()")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 5056c596c3d1848021a4eaa76ee42f4c05c50346 Mon Sep 17 00:00:00 2001 From: Huacai Chen chenhuacai@kernel.org Date: Fri, 26 Jan 2024 16:22:07 +0800 Subject: [PATCH] LoongArch/smp: Call rcutree_report_cpu_starting() at tlb_init()

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

diff --git a/arch/loongarch/kernel/smp.c b/arch/loongarch/kernel/smp.c index a16e3dbe9f09..2b49d30eb7c0 100644 --- a/arch/loongarch/kernel/smp.c +++ b/arch/loongarch/kernel/smp.c @@ -509,7 +509,6 @@ asmlinkage void start_secondary(void) sync_counter(); cpu = raw_smp_processor_id(); set_my_cpu_offset(per_cpu_offset(cpu)); - rcutree_report_cpu_starting(cpu);

cpu_probe(); constant_clockevent_init(); diff --git a/arch/loongarch/mm/tlb.c b/arch/loongarch/mm/tlb.c index 2c0a411f23aa..0b95d32b30c9 100644 --- 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 */ + rcutree_report_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)