mips: switch to generic kernel_thread() (8f54bcac) · Commits · 戴 / test

arch/mips/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -40,6 +40,7 @@ config MIPS
		select HAVE_MOD_ARCH_SPECIFIC
		select MODULES_USE_ELF_REL
		select MODULES_USE_ELF_RELA if 64BIT
		select GENERIC_KERNEL_THREAD

		menu "Machine selection"

arch/mips/include/asm/processor.h

+0 −2

Original line number	Diff line number	Diff line
		@@ -310,8 +310,6 @@ struct task_struct;
		/* Free all resources held by a thread. */
		#define release_thread(thread) do { } while(0)

		extern long kernel_thread(int (fn)(void ), void * arg, unsigned long flags);

		extern unsigned long thread_saved_pc(struct task_struct *tsk);

		/*

arch/mips/kernel/entry.S

+7 −0

Original line number	Diff line number	Diff line
		@@ -65,6 +65,13 @@ need_resched:
		b need_resched
		#endif

		FEXPORT(ret_from_kernel_thread)
		jal schedule_tail # a0 = struct task_struct *prev
		move a0, s1
		jal s0
		li a0, 0
		j sys_exit

		FEXPORT(ret_from_fork)
		jal schedule_tail # a0 = struct task_struct *prev

arch/mips/kernel/mips_ksyms.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -32,8 +32,6 @@ EXPORT_SYMBOL(memset);
		EXPORT_SYMBOL(memcpy);
		EXPORT_SYMBOL(memmove);

		EXPORT_SYMBOL(kernel_thread);

		/*
		* Functions that operate on entire pages. Mostly used by memory management.
		*/

arch/mips/kernel/process.c

+22 −40

Original line number	Diff line number	Diff line
		@@ -84,6 +84,7 @@ void __noreturn cpu_idle(void)
		}

		asmlinkage void ret_from_fork(void);
		asmlinkage void ret_from_kernel_thread(void);

		void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
		{
		@@ -113,7 +114,7 @@ void flush_thread(void)
		}

		int copy_thread(unsigned long clone_flags, unsigned long usp,
		unsigned long unused, struct task_struct p, struct pt_regs regs)
		unsigned long arg, struct task_struct p, struct pt_regs regs)
		{
		struct thread_info *ti = task_thread_info(p);
		struct pt_regs *childregs;
		@@ -136,19 +137,30 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
		childregs = (struct pt_regs *) childksp - 1;
		/* Put the stack after the struct pt_regs. */
		childksp = (unsigned long) childregs;
		p->thread.cp0_status = read_c0_status() & ~(ST0_CU2\|ST0_CU1);
		if (unlikely(p->flags & PF_KTHREAD)) {
		unsigned long status = p->thread.cp0_status;
		memset(childregs, 0, sizeof(struct pt_regs));
		ti->addr_limit = KERNEL_DS;
		p->thread.reg16 = usp; /* fn */
		p->thread.reg17 = arg;
		p->thread.reg29 = childksp;
		p->thread.reg31 = (unsigned long) ret_from_kernel_thread;
		#if defined(CONFIG_CPU_R3000) \|\| defined(CONFIG_CPU_TX39XX)
		status = (status & ~(ST0_KUP \| ST0_IEP \| ST0_IEC)) \|
		((status & (ST0_KUC \| ST0_IEC)) << 2);
		#else
		status \|= ST0_EXL;
		#endif
		childregs->cp0_status = status;
		return 0;
		}
		childregs = regs;
		childregs->regs[7] = 0; /* Clear error flag */

		childregs->regs[2] = 0; /* Child gets zero as return value */

		if (childregs->cp0_status & ST0_CU0) {
		childregs->regs[28] = (unsigned long) ti;
		childregs->regs[29] = childksp;
		ti->addr_limit = KERNEL_DS;
		} else {
		childregs->regs[29] = usp;
		ti->addr_limit = USER_DS;
		}

		p->thread.reg29 = (unsigned long) childregs;
		p->thread.reg31 = (unsigned long) ret_from_fork;

		@@ -156,7 +168,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
		* New tasks lose permission to use the fpu. This accelerates context
		* switching for most programs since they don't use the fpu.
		*/
		p->thread.cp0_status = read_c0_status() & ~(ST0_CU2\|ST0_CU1);
		childregs->cp0_status &= ~(ST0_CU2\|ST0_CU1);

		#ifdef CONFIG_MIPS_MT_SMTC
		@@ -221,35 +232,6 @@ int dump_task_fpu(struct task_struct t, elf_fpregset_t fpr)
		return 1;
		}

		/*
		* Create a kernel thread
		*/
		static void __noreturn kernel_thread_helper(void arg, int (fn)(void *))
		{
		do_exit(fn(arg));
		}

		long kernel_thread(int (fn)(void ), void *arg, unsigned long flags)
		{
		struct pt_regs regs;

		memset(&regs, 0, sizeof(regs));

		regs.regs[4] = (unsigned long) arg;
		regs.regs[5] = (unsigned long) fn;
		regs.cp0_epc = (unsigned long) kernel_thread_helper;
		regs.cp0_status = read_c0_status();
		#if defined(CONFIG_CPU_R3000) \|\| defined(CONFIG_CPU_TX39XX)
		regs.cp0_status = (regs.cp0_status & ~(ST0_KUP \| ST0_IEP \| ST0_IEC)) \|
		((regs.cp0_status & (ST0_KUC \| ST0_IEC)) << 2);
		#else
		regs.cp0_status \|= ST0_EXL;
		#endif

		/* Ok, create the new process.. */
		return do_fork(flags \| CLONE_VM \| CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
		}

		/*
		*
		*/

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