ARC: smp: Move default boot kick/wait code out of MCIP into common code (f33e9c43) · Commits · 戴 / test

arch/arc/kernel/mcip.c

+0 −18

Original line number	Diff line number	Diff line
		@@ -97,26 +97,8 @@ static void mcip_ipi_clear(int irq)
		#endif
		}

		volatile int wake_flag;

		static void mcip_wakeup_cpu(int cpu, unsigned long pc)
		{
		BUG_ON(cpu == 0);
		wake_flag = cpu;
		}

		void arc_platform_smp_wait_to_boot(int cpu)
		{
		while (wake_flag != cpu)
		;

		wake_flag = 0;
		__asm__ __volatile__("j @first_lines_of_secondary \n");
		}

		struct plat_smp_ops plat_smp_ops = {
		.info = smp_cpuinfo_buf,
		.cpu_kick = mcip_wakeup_cpu,
		.ipi_send = mcip_ipi_send,
		.ipi_clear = mcip_ipi_clear,
		};

arch/arc/kernel/smp.c

+21 −25

Original line number	Diff line number	Diff line
		@@ -72,35 +72,29 @@ void __init smp_cpus_done(unsigned int max_cpus)
		}

		/*
		* After power-up, a non Master CPU needs to wait for Master to kick start it
		*
		* The default implementation halts
		*
		* This relies on platform specific support allowing Master to directly set
		* this CPU's PC (to be @first_lines_of_secondary() and kick start it.
		*
		* In lack of such h/w assist, platforms can override this function
		* - make this function busy-spin on a token, eventually set by Master
		* (from arc_platform_smp_wakeup_cpu())
		* - Once token is available, jump to @first_lines_of_secondary
		* (using inline asm).
		*
		* Alert: can NOT use stack here as it has not been determined/setup for CPU.
		* If it turns out to be elaborate, it's better to code it in assembly
		*
		* Default smp boot helper for Run-on-reset case where all cores start off
		* together. Non-masters need to wait for Master to start running.
		* This is implemented using a flag in memory, which Non-masters spin-wait on.
		* Master sets it to cpu-id of core to "ungate" it.
		*/
		void __weak arc_platform_smp_wait_to_boot(int cpu)
		static volatile int wake_flag;

		static void arc_default_smp_cpu_kick(int cpu, unsigned long pc)
		{
		/*
		* As a hack for debugging - since debugger will single-step over the
		* FLAG insn - wrap the halt itself it in a self loop
		*/
		__asm__ __volatile__(
		"1: \n"
		" flag 1 \n"
		" b 1b \n");
		BUG_ON(cpu == 0);
		wake_flag = cpu;
		}

		void arc_platform_smp_wait_to_boot(int cpu)
		{
		while (wake_flag != cpu)
		;

		wake_flag = 0;
		__asm__ __volatile__("j @first_lines_of_secondary \n");
		}


		const char *arc_platform_smp_cpuinfo(void)
		{
		return plat_smp_ops.info ? : "";
		@@ -161,6 +155,8 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
		if (plat_smp_ops.cpu_kick)
		plat_smp_ops.cpu_kick(cpu,
		(unsigned long)first_lines_of_secondary);
		else
		arc_default_smp_cpu_kick(cpu, (unsigned long)NULL);

		/* wait for 1 sec after kicking the secondary */
		wait_till = jiffies + HZ;

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