From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/arch/ia64/include/asm/switch_to.h | 79 ++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 kernel/arch/ia64/include/asm/switch_to.h (limited to 'kernel/arch/ia64/include/asm/switch_to.h') diff --git a/kernel/arch/ia64/include/asm/switch_to.h b/kernel/arch/ia64/include/asm/switch_to.h new file mode 100644 index 000000000..e8f3585e7 --- /dev/null +++ b/kernel/arch/ia64/include/asm/switch_to.h @@ -0,0 +1,79 @@ +/* + * Low-level task switching. This is based on information published in + * the Processor Abstraction Layer and the System Abstraction Layer + * manual. + * + * Copyright (C) 1998-2003 Hewlett-Packard Co + * David Mosberger-Tang + * Copyright (C) 1999 Asit Mallick + * Copyright (C) 1999 Don Dugger + */ +#ifndef _ASM_IA64_SWITCH_TO_H +#define _ASM_IA64_SWITCH_TO_H + +#include + +struct task_struct; + +/* + * Context switch from one thread to another. If the two threads have + * different address spaces, schedule() has already taken care of + * switching to the new address space by calling switch_mm(). + * + * Disabling access to the fph partition and the debug-register + * context switch MUST be done before calling ia64_switch_to() since a + * newly created thread returns directly to + * ia64_ret_from_syscall_clear_r8. + */ +extern struct task_struct *ia64_switch_to (void *next_task); + +extern void ia64_save_extra (struct task_struct *task); +extern void ia64_load_extra (struct task_struct *task); + +#ifdef CONFIG_PERFMON + DECLARE_PER_CPU(unsigned long, pfm_syst_info); +# define PERFMON_IS_SYSWIDE() (__this_cpu_read(pfm_syst_info) & 0x1) +#else +# define PERFMON_IS_SYSWIDE() (0) +#endif + +#define IA64_HAS_EXTRA_STATE(t) \ + ((t)->thread.flags & (IA64_THREAD_DBG_VALID|IA64_THREAD_PM_VALID) \ + || PERFMON_IS_SYSWIDE()) + +#define __switch_to(prev,next,last) do { \ + if (IA64_HAS_EXTRA_STATE(prev)) \ + ia64_save_extra(prev); \ + if (IA64_HAS_EXTRA_STATE(next)) \ + ia64_load_extra(next); \ + ia64_psr(task_pt_regs(next))->dfh = !ia64_is_local_fpu_owner(next); \ + (last) = ia64_switch_to((next)); \ +} while (0) + +#ifdef CONFIG_SMP +/* + * In the SMP case, we save the fph state when context-switching away from a thread that + * modified fph. This way, when the thread gets scheduled on another CPU, the CPU can + * pick up the state from task->thread.fph, avoiding the complication of having to fetch + * the latest fph state from another CPU. In other words: eager save, lazy restore. + */ +# define switch_to(prev,next,last) do { \ + if (ia64_psr(task_pt_regs(prev))->mfh && ia64_is_local_fpu_owner(prev)) { \ + ia64_psr(task_pt_regs(prev))->mfh = 0; \ + (prev)->thread.flags |= IA64_THREAD_FPH_VALID; \ + __ia64_save_fpu((prev)->thread.fph); \ + } \ + __switch_to(prev, next, last); \ + /* "next" in old context is "current" in new context */ \ + if (unlikely((current->thread.flags & IA64_THREAD_MIGRATION) && \ + (task_cpu(current) != \ + task_thread_info(current)->last_cpu))) { \ + platform_migrate(current); \ + task_thread_info(current)->last_cpu = task_cpu(current); \ + } \ +} while (0) +#else +# define switch_to(prev,next,last) __switch_to(prev, next, last) +#endif + +#endif /* _ASM_IA64_SWITCH_TO_H */ -- cgit 1.2.3-korg