[patch v2 07/35] Hexagon: Add threadinfo

Richard Kuo
2011-08-30T19:23:05Z

[-- Attachment #1: thread.diff --]
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Removed some cruft and changed to allow kernel stack to be smaller than a page
size.

I left the thread_info alignment alone for the time being; may revisit that in
the future.

Signed-off-by: Richard Kuo <rkuo@codeaurora.org>

---
arch/hexagon/include/asm/thread_info.h | 154 +++++++++++++++++++++++++++++++++
1 file changed, 154 insertions(+)

Index: linux-hexagon-kernel/arch/hexagon/include/asm/thread_info.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-hexagon-kernel/arch/hexagon/include/asm/thread_info.h 2011-08-24 18:45:48.123877096 -0500
@@ -0,0 +1,154 @@
+/*
+ * Thread support for the Hexagon architecture
+ *
+ * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#ifndef _ASM_THREAD_INFO_H
+#define _ASM_THREAD_INFO_H
+
+#ifdef __KERNEL__
+
+#ifndef __ASSEMBLY__
+#include <asm/processor.h>
+#include <asm/registers.h>
+#include <asm/page.h>
+#endif
+
+#define THREAD_SHIFT 12
+#define THREAD_SIZE (1<<THREAD_SHIFT)
+
+#if THREAD_SHIFT >= PAGE_SHIFT
+#define THREAD_SIZE_ORDER (THREAD_SHIFT - PAGE_SHIFT)
+#else /* don't use standard allocator */
+#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
+extern struct thread_info *alloc_thread_info_node(struct task_struct *tsk, int node);
+extern void free_thread_info(struct thread_info *ti);
+#endif
+
+
+#ifndef __ASSEMBLY__
+
+typedef struct {
+ unsigned long seg;
+} mm_segment_t;
+
+/*
+ * This is union'd with the "bottom" of the kernel stack.
+ * It keeps track of thread info which is handy for routines
+ * to access quickly.
+ */
+
+struct thread_info {
+ struct task_struct *task; /* main task structure */
+ struct exec_domain *exec_domain; /* execution domain */
+ unsigned long flags; /* low level flags */
+ __u32 cpu; /* current cpu */
+ int preempt_count; /* 0=>preemptible,<0=>BUG */
+ mm_segment_t addr_limit; /* segmentation sux */
+ /*
+ * used for syscalls somehow;
+ * seems to have a function pointer and four arguments
+ */
+ struct restart_block restart_block;
+ /* Points to the current pt_regs frame */
+ struct pt_regs *regs;
+ /*
+ * saved kernel sp at switch_to time;
+ * not sure if this is used (it's not in the VM model it seems;
+ * see thread_struct)
+ */
+ unsigned long sp;
+};
+
+#else /* !__ASSEMBLY__ */
+
+#include <asm/asm-offsets.h>
+
+#endif /* __ASSEMBLY__ */
+
+/* looks like "linux/hardirq.h" uses this. */
+
+#define PREEMPT_ACTIVE 0x10000000
+
+#ifndef __ASSEMBLY__
+
+#define INIT_THREAD_INFO(tsk) \
+{ \
+ .task = &tsk, \
+ .exec_domain = &default_exec_domain, \
+ .flags = 0, \
+ .cpu = 0, \
+ .preempt_count = 1, \
+ .addr_limit = KERNEL_DS, \
+ .restart_block = { \
+ .fn = do_no_restart_syscall, \
+ }, \
+ .sp = 0, \
+ .regs = NULL, \
+}
+
+#define init_thread_info (init_thread_union.thread_info)
+#define init_stack (init_thread_union.stack)
+
+/* Tacky preprocessor trickery */
+#define qqstr(s) qstr(s)
+#define qstr(s) #s
+#define QUOTED_THREADINFO_REG qqstr(THREADINFO_REG)
+
+register struct thread_info *__current_thread_info asm(QUOTED_THREADINFO_REG);
+#define current_thread_info() __current_thread_info
+
+#endif /* __ASSEMBLY__ */
+
+/*
+ * 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
+ */
+
+#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
+#define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
+#define TIF_SIGPENDING 2 /* signal pending */
+#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
+#define TIF_SINGLESTEP 4 /* restore ss @ return to usr mode */
+#define TIF_IRET 5 /* return with iret */
+#define TIF_RESTORE_SIGMASK 6 /* restore sig mask in do_signal() */
+/* true if poll_idle() is polling TIF_NEED_RESCHED */
+#define TIF_POLLING_NRFLAG 16
+#define TIF_MEMDIE 17 /* OOM killer killed process */
+
+#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
+#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
+#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
+#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
+#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
+#define _TIF_IRET (1 << TIF_IRET)
+#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK)
+#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
+
+/* work to do on interrupt/exception return - All but TIF_SYSCALL_TRACE */
+#define _TIF_WORK_MASK (0x0000FFFF & ~_TIF_SYSCALL_TRACE)
+
+/* work to do on any return to u-space */
+#define _TIF_ALLWORK_MASK 0x0000FFFF
+
+#endif /* __KERNEL__ */
+
+#endif

--

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