C6X: process management

Original port to early 2.6 kernel using TI COFF toolchain.
Brought up to date by Mark Salter <msalter@redhat.com>

Signed-off-by: Aurelien Jacquiot <a-jacquiot@ti.com>
Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

2 files changed, 253 insertions, 0 deletions

diff --git a/arch/c6x/include/asm/processor.h b/arch/c6x/include/asm/processor.h
new file mode 100644
index 000000000000..8154c4ee8c9c
--- /dev/null
+++ b/arch/c6x/include/asm/processor.h
@@ -0,0 +1,132 @@
+/*
+ *  Port on Texas Instruments TMS320C6x architecture
+ *
+ *  Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated
+ *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
+ *
+ *  Updated for 2.6.34: Mark Salter <msalter@redhat.com>
+ *
+ *  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.
+ */
+#ifndef _ASM_C6X_PROCESSOR_H
+#define _ASM_C6X_PROCESSOR_H
+
+#include <asm/ptrace.h>
+#include <asm/page.h>
+#include <asm/current.h>
+
+/*
+ * Default implementation of macro that returns current
+ * instruction pointer ("program counter").
+ */
+#define current_text_addr()			\
+({						\
+	void *__pc;				\
+	asm("mvc .S2 pce1,%0\n" : "=b"(__pc));	\
+	__pc;					\
+})
+
+/*
+ * User space process size. This is mostly meaningless for NOMMU
+ * but some C6X processors may have RAM addresses up to 0xFFFFFFFF.
+ * Since calls like mmap() can return an address or an error, we
+ * have to allow room for error returns when code does something
+ * like:
+ *
+ *       addr = do_mmap(...)
+ *       if ((unsigned long)addr >= TASK_SIZE)
+ *            ... its an error code, not an address ...
+ *
+ * Here, we allow for 4096 error codes which means we really can't
+ * use the last 4K page on systems with RAM extending all the way
+ * to the end of the 32-bit address space.
+ */
+#define TASK_SIZE	0xFFFFF000
+
+/*
+ * This decides where the kernel will search for a free chunk of vm
+ * space during mmap's. We won't be using it
+ */
+#define TASK_UNMAPPED_BASE	0
+
+struct thread_struct {
+	unsigned long long b15_14;
+	unsigned long long a15_14;
+	unsigned long long b13_12;
+	unsigned long long a13_12;
+	unsigned long long b11_10;
+	unsigned long long a11_10;
+	unsigned long long ricl_icl;
+	unsigned long  usp;		/* user stack pointer */
+	unsigned long  pc;		/* kernel pc */
+	unsigned long  wchan;
+};
+
+#define INIT_THREAD					\
+{							\
+	.usp = 0,					\
+	.wchan = 0,					\
+}
+
+#define INIT_MMAP { \
+	&init_mm, 0, 0, NULL, PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC, 1, \
+	NULL, NULL }
+
+#define task_pt_regs(task) \
+	((struct pt_regs *)(THREAD_START_SP + task_stack_page(task)) - 1)
+
+#define alloc_kernel_stack()	__get_free_page(GFP_KERNEL)
+#define free_kernel_stack(page) free_page((page))
+
+
+/* Forward declaration, a strange C thing */
+struct task_struct;
+
+extern void start_thread(struct pt_regs *regs, unsigned int pc,
+			 unsigned long usp);
+
+/* Free all resources held by a thread. */
+static inline void release_thread(struct task_struct *dead_task)
+{
+}
+
+/* Prepare to copy thread state - unlazy all lazy status */
+#define prepare_to_copy(tsk)	do { } while (0)
+
+extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
+
+#define copy_segments(tsk, mm)		do { } while (0)
+#define release_segments(mm)		do { } while (0)
+
+/*
+ * saved PC of a blocked thread.
+ */
+#define thread_saved_pc(tsk) (task_pt_regs(tsk)->pc)
+
+/*
+ * saved kernel SP and DP of a blocked thread.
+ */
+#ifdef _BIG_ENDIAN
+#define thread_saved_ksp(tsk) \
+	(*(unsigned long *)&(tsk)->thread.b15_14)
+#define thread_saved_dp(tsk) \
+	(*(((unsigned long *)&(tsk)->thread.b15_14) + 1))
+#else
+#define thread_saved_ksp(tsk) \
+	(*(((unsigned long *)&(tsk)->thread.b15_14) + 1))
+#define thread_saved_dp(tsk) \
+	(*(unsigned long *)&(tsk)->thread.b15_14)
+#endif
+
+extern unsigned long get_wchan(struct task_struct *p);
+
+#define KSTK_EIP(tsk)	(task_pt_regs(task)->pc)
+#define	KSTK_ESP(tsk)	(task_pt_regs(task)->sp)
+
+#define cpu_relax()		do { } while (0)
+
+extern const struct seq_operations cpuinfo_op;
+
+#endif /* ASM_C6X_PROCESSOR_H */
diff --git a/arch/c6x/include/asm/thread_info.h b/arch/c6x/include/asm/thread_info.h
new file mode 100644
index 000000000000..fd99148cda9d
--- /dev/null
+++ b/arch/c6x/include/asm/thread_info.h
@@ -0,0 +1,121 @@
+/*
+ *  Port on Texas Instruments TMS320C6x architecture
+ *
+ *  Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated
+ *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
+ *
+ *  Updated for 2.6.3x: Mark Salter <msalter@redhat.com>
+ *
+ *  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.
+ */
+#ifndef _ASM_C6X_THREAD_INFO_H
+#define _ASM_C6X_THREAD_INFO_H
+
+#ifdef __KERNEL__
+
+#include <asm/page.h>
+
+#ifdef CONFIG_4KSTACKS
+#define THREAD_SIZE		4096
+#define THREAD_SHIFT		12
+#define THREAD_ORDER		0
+#else
+#define THREAD_SIZE		8192
+#define THREAD_SHIFT		13
+#define THREAD_ORDER		1
+#endif
+
+#define THREAD_START_SP		(THREAD_SIZE - 8)
+
+#ifndef __ASSEMBLY__
+
+typedef struct {
+	unsigned long seg;
+} mm_segment_t;
+
+/*
+ * low level task data.
+ */
+struct thread_info {
+	struct task_struct	*task;		/* main task structure */
+	struct exec_domain	*exec_domain;	/* execution domain */
+	unsigned long		flags;		/* low level flags */
+	int			cpu;		/* cpu we're on */
+	int			preempt_count;	/* 0 = preemptable, <0 = BUG */
+	mm_segment_t		addr_limit;	/* thread address space */
+	struct restart_block	restart_block;
+};
+
+/*
+ * macros/functions for gaining access to the thread information structure
+ *
+ * preempt_count needs to be 1 initially, until the scheduler is functional.
+ */
+#define INIT_THREAD_INFO(tsk)			\
+{						\
+	.task		= &tsk,			\
+	.exec_domain	= &default_exec_domain,	\
+	.flags		= 0,			\
+	.cpu		= 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)
+
+/* get the thread information struct of current task */
+static inline __attribute__((const))
+struct thread_info *current_thread_info(void)
+{
+	struct thread_info *ti;
+	asm volatile (" clr   .s2 B15,0,%1,%0\n"
+		      : "=b" (ti)
+		      : "Iu5" (THREAD_SHIFT - 1));
+	return ti;
+}
+
+#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
+
+/* thread information allocation */
+#ifdef CONFIG_DEBUG_STACK_USAGE
+#define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO)
+#else
+#define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK)
+#endif
+
+#define alloc_thread_info_node(tsk, node)	\
+	((struct thread_info *)__get_free_pages(THREAD_FLAGS, THREAD_ORDER))
+
+#define free_thread_info(ti)	free_pages((unsigned long) (ti), THREAD_ORDER)
+#define get_thread_info(ti)	get_task_struct((ti)->task)
+#define put_thread_info(ti)	put_task_struct((ti)->task)
+#endif /* __ASSEMBLY__ */
+
+#define	PREEMPT_ACTIVE	0x10000000
+
+/*
+ * thread information flag bit numbers
+ * - 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_RESTORE_SIGMASK	4	/* restore signal mask in do_signal() */
+
+#define TIF_POLLING_NRFLAG	16	/* true if polling TIF_NEED_RESCHED */
+#define TIF_MEMDIE		17	/* OOM killer killed process */
+
+#define TIF_WORK_MASK		0x00007FFE /* work on irq/exception return */
+#define TIF_ALLWORK_MASK	0x00007FFF /* work on any return to u-space */
+
+#endif /* __KERNEL__ */
+
+#endif /* _ASM_C6X_THREAD_INFO_H */