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author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/ia64/include/asm/switch_to.h | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
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 <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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 <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/ia64/include/asm/switch_to.h')
-rw-r--r-- | kernel/arch/ia64/include/asm/switch_to.h | 79 |
1 files changed, 79 insertions, 0 deletions
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 <davidm@hpl.hp.com> + * Copyright (C) 1999 Asit Mallick <asit.k.mallick@intel.com> + * Copyright (C) 1999 Don Dugger <don.dugger@intel.com> + */ +#ifndef _ASM_IA64_SWITCH_TO_H +#define _ASM_IA64_SWITCH_TO_H + +#include <linux/percpu.h> + +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 */ |