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authorCatalin Marinas <catalin.marinas@arm.com>2012-03-05 11:49:28 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2012-09-17 13:41:58 +0100
commitb3901d54dc4f73acdc6b7c6e5a7a496d3afeae61 (patch)
treed7948a9ba283b767beced9f03f4effc26c120304 /arch/arm64/include/asm/thread_info.h
parent1d18c47c735e8adfe531fc41fae31e98f86b68fe (diff)
arm64: Process management
The patch adds support for thread creation and context switching. The context switching CPU specific code is introduced with the CPU support patch (part of the arch/arm64/mm/proc.S file). AArch64 supports ASID-tagged TLBs and the ASID can be either 8 or 16-bit wide (detectable via the ID_AA64AFR0_EL1 register). Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/arm64/include/asm/thread_info.h')
-rw-r--r--arch/arm64/include/asm/thread_info.h127
1 files changed, 127 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
new file mode 100644
index 000000000000..3659e460071d
--- /dev/null
+++ b/arch/arm64/include/asm/thread_info.h
@@ -0,0 +1,127 @@
+/*
+ * Based on arch/arm/include/asm/thread_info.h
+ *
+ * Copyright (C) 2002 Russell King.
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __ASM_THREAD_INFO_H
+#define __ASM_THREAD_INFO_H
+
+#ifdef __KERNEL__
+
+#include <linux/compiler.h>
+
+#ifndef CONFIG_ARM64_64K_PAGES
+#define THREAD_SIZE_ORDER 1
+#endif
+
+#define THREAD_SIZE 8192
+#define THREAD_START_SP (THREAD_SIZE - 16)
+
+#ifndef __ASSEMBLY__
+
+struct task_struct;
+struct exec_domain;
+
+#include <asm/types.h>
+
+typedef unsigned long mm_segment_t;
+
+/*
+ * low level task data that entry.S needs immediate access to.
+ * __switch_to() assumes cpu_context follows immediately after cpu_domain.
+ */
+struct thread_info {
+ unsigned long flags; /* low level flags */
+ mm_segment_t addr_limit; /* address limit */
+ struct task_struct *task; /* main task structure */
+ struct exec_domain *exec_domain; /* execution domain */
+ struct restart_block restart_block;
+ int preempt_count; /* 0 => preemptable, <0 => bug */
+ int cpu; /* cpu */
+};
+
+#define INIT_THREAD_INFO(tsk) \
+{ \
+ .task = &tsk, \
+ .exec_domain = &default_exec_domain, \
+ .flags = 0, \
+ .preempt_count = INIT_PREEMPT_COUNT, \
+ .addr_limit = KERNEL_DS, \
+ .restart_block = { \
+ .fn = do_no_restart_syscall, \
+ }, \
+}
+
+#define init_thread_info (init_thread_union.thread_info)
+#define init_stack (init_thread_union.stack)
+
+/*
+ * how to get the thread information struct from C
+ */
+static inline struct thread_info *current_thread_info(void) __attribute_const__;
+
+static inline struct thread_info *current_thread_info(void)
+{
+ register unsigned long sp asm ("sp");
+ return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
+}
+
+#define thread_saved_pc(tsk) \
+ ((unsigned long)(tsk->thread.cpu_context.pc))
+#define thread_saved_sp(tsk) \
+ ((unsigned long)(tsk->thread.cpu_context.sp))
+#define thread_saved_fp(tsk) \
+ ((unsigned long)(tsk->thread.cpu_context.fp))
+
+#endif
+
+/*
+ * We use bit 30 of the preempt_count to indicate that kernel
+ * preemption is occurring. See <asm/hardirq.h>.
+ */
+#define PREEMPT_ACTIVE 0x40000000
+
+/*
+ * thread information flags:
+ * TIF_SYSCALL_TRACE - syscall trace active
+ * TIF_SIGPENDING - signal pending
+ * TIF_NEED_RESCHED - rescheduling necessary
+ * TIF_NOTIFY_RESUME - callback before returning to user
+ * TIF_USEDFPU - FPU was used by this task this quantum (SMP)
+ * TIF_POLLING_NRFLAG - true if poll_idle() is polling TIF_NEED_RESCHED
+ */
+#define TIF_SIGPENDING 0
+#define TIF_NEED_RESCHED 1
+#define TIF_NOTIFY_RESUME 2 /* callback before returning to user */
+#define TIF_SYSCALL_TRACE 8
+#define TIF_POLLING_NRFLAG 16
+#define TIF_MEMDIE 18 /* is terminating due to OOM killer */
+#define TIF_FREEZE 19
+#define TIF_RESTORE_SIGMASK 20
+#define TIF_SINGLESTEP 21
+#define TIF_32BIT 22 /* 32bit process */
+#define TIF_SWITCH_MM 23 /* deferred switch_mm */
+
+#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
+#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
+#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
+#define _TIF_32BIT (1 << TIF_32BIT)
+
+#define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
+ _TIF_NOTIFY_RESUME)
+
+#endif /* __KERNEL__ */
+#endif /* __ASM_THREAD_INFO_H */