Hi, Greg,

On Tue, Jan 30, 2024 at 12:53 AM gregkh@linuxfoundation.org wrote:

The patch below does not apply to the 6.1-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-6.1.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 '2024012911-outright-violin-e677@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:

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

Similar to the commit which it fixes, please change rcutree_report_cpu_starting() to rcu_cpu_starting() in the code.

Huacai

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)