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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/x86/include/asm/thread_info.h
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (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/x86/include/asm/thread_info.h')
-rw-r--r--kernel/arch/x86/include/asm/thread_info.h303
1 files changed, 303 insertions, 0 deletions
diff --git a/kernel/arch/x86/include/asm/thread_info.h b/kernel/arch/x86/include/asm/thread_info.h
new file mode 100644
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--- /dev/null
+++ b/kernel/arch/x86/include/asm/thread_info.h
@@ -0,0 +1,303 @@
+/* thread_info.h: low-level thread information
+ *
+ * Copyright (C) 2002 David Howells (dhowells@redhat.com)
+ * - Incorporating suggestions made by Linus Torvalds and Dave Miller
+ */
+
+#ifndef _ASM_X86_THREAD_INFO_H
+#define _ASM_X86_THREAD_INFO_H
+
+#include <linux/compiler.h>
+#include <asm/page.h>
+#include <asm/percpu.h>
+#include <asm/types.h>
+
+/*
+ * TOP_OF_KERNEL_STACK_PADDING is a number of unused bytes that we
+ * reserve at the top of the kernel stack. We do it because of a nasty
+ * 32-bit corner case. On x86_32, the hardware stack frame is
+ * variable-length. Except for vm86 mode, struct pt_regs assumes a
+ * maximum-length frame. If we enter from CPL 0, the top 8 bytes of
+ * pt_regs don't actually exist. Ordinarily this doesn't matter, but it
+ * does in at least one case:
+ *
+ * If we take an NMI early enough in SYSENTER, then we can end up with
+ * pt_regs that extends above sp0. On the way out, in the espfix code,
+ * we can read the saved SS value, but that value will be above sp0.
+ * Without this offset, that can result in a page fault. (We are
+ * careful that, in this case, the value we read doesn't matter.)
+ *
+ * In vm86 mode, the hardware frame is much longer still, but we neither
+ * access the extra members from NMI context, nor do we write such a
+ * frame at sp0 at all.
+ *
+ * x86_64 has a fixed-length stack frame.
+ */
+#ifdef CONFIG_X86_32
+# define TOP_OF_KERNEL_STACK_PADDING 8
+#else
+# define TOP_OF_KERNEL_STACK_PADDING 0
+#endif
+
+/*
+ * low level task data that entry.S needs immediate access to
+ * - this struct should fit entirely inside of one cache line
+ * - this struct shares the supervisor stack pages
+ */
+#ifndef __ASSEMBLY__
+struct task_struct;
+#include <asm/processor.h>
+#include <linux/atomic.h>
+
+struct thread_info {
+ struct task_struct *task; /* main task structure */
+ __u32 flags; /* low level flags */
+ __u32 status; /* thread synchronous flags */
+ __u32 cpu; /* current CPU */
+ int saved_preempt_count;
+ int preempt_lazy_count; /* 0 => lazy preemptable
+ <0 => BUG */
+ mm_segment_t addr_limit;
+ void __user *sysenter_return;
+ unsigned int sig_on_uaccess_error:1;
+ unsigned int uaccess_err:1; /* uaccess failed */
+};
+
+#define INIT_THREAD_INFO(tsk) \
+{ \
+ .task = &tsk, \
+ .flags = 0, \
+ .cpu = 0, \
+ .saved_preempt_count = INIT_PREEMPT_COUNT, \
+ .addr_limit = KERNEL_DS, \
+}
+
+#define init_thread_info (init_thread_union.thread_info)
+#define init_stack (init_thread_union.stack)
+
+#else /* !__ASSEMBLY__ */
+
+#include <asm/asm-offsets.h>
+
+#endif
+
+/*
+ * thread information flags
+ * - these are process state flags that various assembly files
+ * may need to access
+ * - pending work-to-be-done flags are in LSW
+ * - other flags in MSW
+ * Warning: layout of LSW is hardcoded in entry.S
+ */
+#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
+#define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
+#define TIF_SIGPENDING 2 /* signal pending */
+#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
+#define TIF_SINGLESTEP 4 /* reenable singlestep on user return*/
+#define TIF_SYSCALL_EMU 6 /* syscall emulation active */
+#define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
+#define TIF_SECCOMP 8 /* secure computing */
+#define TIF_NEED_RESCHED_LAZY 9 /* lazy rescheduling necessary */
+#define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */
+#define TIF_UPROBE 12 /* breakpointed or singlestepping */
+#define TIF_NOTSC 16 /* TSC is not accessible in userland */
+#define TIF_IA32 17 /* IA32 compatibility process */
+#define TIF_FORK 18 /* ret_from_fork */
+#define TIF_NOHZ 19 /* in adaptive nohz mode */
+#define TIF_MEMDIE 20 /* is terminating due to OOM killer */
+#define TIF_POLLING_NRFLAG 21 /* idle is polling for TIF_NEED_RESCHED */
+#define TIF_IO_BITMAP 22 /* uses I/O bitmap */
+#define TIF_FORCED_TF 24 /* true if TF in eflags artificially */
+#define TIF_BLOCKSTEP 25 /* set when we want DEBUGCTLMSR_BTF */
+#define TIF_LAZY_MMU_UPDATES 27 /* task is updating the mmu lazily */
+#define TIF_SYSCALL_TRACEPOINT 28 /* syscall tracepoint instrumentation */
+#define TIF_ADDR32 29 /* 32-bit address space on 64 bits */
+#define TIF_X32 30 /* 32-bit native x86-64 binary */
+
+#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
+#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
+#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
+#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
+#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
+#define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU)
+#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
+#define _TIF_SECCOMP (1 << TIF_SECCOMP)
+#define _TIF_NEED_RESCHED_LAZY (1 << TIF_NEED_RESCHED_LAZY)
+#define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY)
+#define _TIF_UPROBE (1 << TIF_UPROBE)
+#define _TIF_NOTSC (1 << TIF_NOTSC)
+#define _TIF_IA32 (1 << TIF_IA32)
+#define _TIF_FORK (1 << TIF_FORK)
+#define _TIF_NOHZ (1 << TIF_NOHZ)
+#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
+#define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
+#define _TIF_FORCED_TF (1 << TIF_FORCED_TF)
+#define _TIF_BLOCKSTEP (1 << TIF_BLOCKSTEP)
+#define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES)
+#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
+#define _TIF_ADDR32 (1 << TIF_ADDR32)
+#define _TIF_X32 (1 << TIF_X32)
+
+/* work to do in syscall_trace_enter() */
+#define _TIF_WORK_SYSCALL_ENTRY \
+ (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT | \
+ _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT | \
+ _TIF_NOHZ)
+
+/* work to do in syscall_trace_leave() */
+#define _TIF_WORK_SYSCALL_EXIT \
+ (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP | \
+ _TIF_SYSCALL_TRACEPOINT | _TIF_NOHZ)
+
+/* work to do on interrupt/exception return */
+#define _TIF_WORK_MASK \
+ (0x0000FFFF & \
+ ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT| \
+ _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU))
+
+/* work to do on any return to user space */
+#define _TIF_ALLWORK_MASK \
+ ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT | \
+ _TIF_NOHZ)
+
+/* Only used for 64 bit */
+#define _TIF_DO_NOTIFY_MASK \
+ (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | \
+ _TIF_USER_RETURN_NOTIFY | _TIF_UPROBE)
+
+/* flags to check in __switch_to() */
+#define _TIF_WORK_CTXSW \
+ (_TIF_IO_BITMAP|_TIF_NOTSC|_TIF_BLOCKSTEP)
+
+#define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
+#define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW)
+
+#define _TIF_NEED_RESCHED_MASK (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)
+
+#define STACK_WARN (THREAD_SIZE/8)
+
+/*
+ * macros/functions for gaining access to the thread information structure
+ *
+ * preempt_count needs to be 1 initially, until the scheduler is functional.
+ */
+#ifndef __ASSEMBLY__
+
+DECLARE_PER_CPU(unsigned long, kernel_stack);
+
+static inline struct thread_info *current_thread_info(void)
+{
+ return (struct thread_info *)(current_top_of_stack() - THREAD_SIZE);
+}
+
+static inline unsigned long current_stack_pointer(void)
+{
+ unsigned long sp;
+#ifdef CONFIG_X86_64
+ asm("mov %%rsp,%0" : "=g" (sp));
+#else
+ asm("mov %%esp,%0" : "=g" (sp));
+#endif
+ return sp;
+}
+
+#else /* !__ASSEMBLY__ */
+
+/* Load thread_info address into "reg" */
+#define GET_THREAD_INFO(reg) \
+ _ASM_MOV PER_CPU_VAR(kernel_stack),reg ; \
+ _ASM_SUB $(THREAD_SIZE),reg ;
+
+/*
+ * ASM operand which evaluates to a 'thread_info' address of
+ * the current task, if it is known that "reg" is exactly "off"
+ * bytes below the top of the stack currently.
+ *
+ * ( The kernel stack's size is known at build time, it is usually
+ * 2 or 4 pages, and the bottom of the kernel stack contains
+ * the thread_info structure. So to access the thread_info very
+ * quickly from assembly code we can calculate down from the
+ * top of the kernel stack to the bottom, using constant,
+ * build-time calculations only. )
+ *
+ * For example, to fetch the current thread_info->flags value into %eax
+ * on x86-64 defconfig kernels, in syscall entry code where RSP is
+ * currently at exactly SIZEOF_PTREGS bytes away from the top of the
+ * stack:
+ *
+ * mov ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS), %eax
+ *
+ * will translate to:
+ *
+ * 8b 84 24 b8 c0 ff ff mov -0x3f48(%rsp), %eax
+ *
+ * which is below the current RSP by almost 16K.
+ */
+#define ASM_THREAD_INFO(field, reg, off) ((field)+(off)-THREAD_SIZE)(reg)
+
+#endif
+
+/*
+ * Thread-synchronous status.
+ *
+ * This is different from the flags in that nobody else
+ * ever touches our thread-synchronous status, so we don't
+ * have to worry about atomic accesses.
+ */
+#define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/
+#define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */
+
+#ifndef __ASSEMBLY__
+#define HAVE_SET_RESTORE_SIGMASK 1
+static inline void set_restore_sigmask(void)
+{
+ struct thread_info *ti = current_thread_info();
+ ti->status |= TS_RESTORE_SIGMASK;
+ WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));
+}
+static inline void clear_restore_sigmask(void)
+{
+ current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
+}
+static inline bool test_restore_sigmask(void)
+{
+ return current_thread_info()->status & TS_RESTORE_SIGMASK;
+}
+static inline bool test_and_clear_restore_sigmask(void)
+{
+ struct thread_info *ti = current_thread_info();
+ if (!(ti->status & TS_RESTORE_SIGMASK))
+ return false;
+ ti->status &= ~TS_RESTORE_SIGMASK;
+ return true;
+}
+
+static inline bool is_ia32_task(void)
+{
+#ifdef CONFIG_X86_32
+ return true;
+#endif
+#ifdef CONFIG_IA32_EMULATION
+ if (current_thread_info()->status & TS_COMPAT)
+ return true;
+#endif
+ return false;
+}
+
+/*
+ * Force syscall return via IRET by making it look as if there was
+ * some work pending. IRET is our most capable (but slowest) syscall
+ * return path, which is able to restore modified SS, CS and certain
+ * EFLAGS values that other (fast) syscall return instructions
+ * are not able to restore properly.
+ */
+#define force_iret() set_thread_flag(TIF_NOTIFY_RESUME)
+
+#endif /* !__ASSEMBLY__ */
+
+#ifndef __ASSEMBLY__
+extern void arch_task_cache_init(void);
+extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
+extern void arch_release_task_struct(struct task_struct *tsk);
+#endif
+#endif /* _ASM_X86_THREAD_INFO_H */