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Subject[PATCH v7 13/37] nds32: Process management
Date
This patch includes copy_thread(), start_thread() implementation and cpu_context
structure definition. nds32 uses $r25 to get current task_struct.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
---
arch/nds32/include/asm/current.h | 12 ++
arch/nds32/include/asm/processor.h | 103 +++++++++++++++++
arch/nds32/include/asm/thread_info.h | 76 +++++++++++++
arch/nds32/kernel/process.c | 208 +++++++++++++++++++++++++++++++++++
4 files changed, 399 insertions(+)
create mode 100644 arch/nds32/include/asm/current.h
create mode 100644 arch/nds32/include/asm/processor.h
create mode 100644 arch/nds32/include/asm/thread_info.h
create mode 100644 arch/nds32/kernel/process.c

diff --git a/arch/nds32/include/asm/current.h b/arch/nds32/include/asm/current.h
new file mode 100644
index 000000000000..b4dcd22b7bcb
--- /dev/null
+++ b/arch/nds32/include/asm/current.h
@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#ifndef _ASM_NDS32_CURRENT_H
+#define _ASM_NDS32_CURRENT_H
+
+#ifndef __ASSEMBLY__
+register struct task_struct *current asm("$r25");
+#endif /* __ASSEMBLY__ */
+#define tsk $r25
+
+#endif /* _ASM_NDS32_CURRENT_H */
diff --git a/arch/nds32/include/asm/processor.h b/arch/nds32/include/asm/processor.h
new file mode 100644
index 000000000000..9c83caf4269f
--- /dev/null
+++ b/arch/nds32/include/asm/processor.h
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#ifndef __ASM_NDS32_PROCESSOR_H
+#define __ASM_NDS32_PROCESSOR_H
+
+/*
+ * Default implementation of macro that returns current
+ * instruction pointer ("program counter").
+ */
+#define current_text_addr() ({ __label__ _l; _l: &&_l;})
+
+#ifdef __KERNEL__
+
+#include <asm/ptrace.h>
+#include <asm/types.h>
+#include <asm/sigcontext.h>
+
+#define KERNEL_STACK_SIZE PAGE_SIZE
+#define STACK_TOP TASK_SIZE
+#define STACK_TOP_MAX TASK_SIZE
+
+struct cpu_context {
+ unsigned long r6;
+ unsigned long r7;
+ unsigned long r8;
+ unsigned long r9;
+ unsigned long r10;
+ unsigned long r11;
+ unsigned long r12;
+ unsigned long r13;
+ unsigned long r14;
+ unsigned long fp;
+ unsigned long pc;
+ unsigned long sp;
+};
+
+struct thread_struct {
+ struct cpu_context cpu_context; /* cpu context */
+ /* fault info */
+ unsigned long address;
+ unsigned long trap_no;
+ unsigned long error_code;
+};
+
+#define INIT_THREAD { }
+
+#ifdef __NDS32_EB__
+#define PSW_DE PSW_mskBE
+#else
+#define PSW_DE 0x0
+#endif
+
+#ifdef CONFIG_WBNA
+#define PSW_valWBNA PSW_mskWBNA
+#else
+#define PSW_valWBNA 0x0
+#endif
+
+#ifdef CONFIG_HWZOL
+#define PSW_valINIT (PSW_CPL_ANY | PSW_mskAEN | PSW_valWBNA | PSW_mskDT | PSW_mskIT | PSW_DE | PSW_mskGIE)
+#else
+#define PSW_valINIT (PSW_CPL_ANY | PSW_valWBNA | PSW_mskDT | PSW_mskIT | PSW_DE | PSW_mskGIE)
+#endif
+
+#define start_thread(regs,pc,stack) \
+({ \
+ memzero(regs, sizeof(struct pt_regs)); \
+ forget_syscall(regs); \
+ regs->ipsw = PSW_valINIT; \
+ regs->ir0 = (PSW_CPL_ANY | PSW_valWBNA | PSW_mskDT | PSW_mskIT | PSW_DE | PSW_SYSTEM | PSW_INTL_1); \
+ regs->ipc = pc; \
+ regs->sp = stack; \
+})
+
+/* Forward declaration, a strange C thing */
+struct task_struct;
+
+/* Free all resources held by a thread. */
+#define release_thread(thread) do { } while(0)
+
+/* Prepare to copy thread state - unlazy all lazy status */
+#define prepare_to_copy(tsk) do { } while (0)
+
+unsigned long get_wchan(struct task_struct *p);
+
+#define cpu_relax() barrier()
+
+#define task_pt_regs(task) \
+ ((struct pt_regs *) (task_stack_page(task) + THREAD_SIZE \
+ - 8) - 1)
+
+/*
+ * Create a new kernel thread
+ */
+extern int kernel_thread(int (*fn) (void *), void *arg, unsigned long flags);
+
+#define KSTK_EIP(tsk) instruction_pointer(task_pt_regs(tsk))
+#define KSTK_ESP(tsk) user_stack_pointer(task_pt_regs(tsk))
+
+#endif
+
+#endif /* __ASM_NDS32_PROCESSOR_H */
diff --git a/arch/nds32/include/asm/thread_info.h b/arch/nds32/include/asm/thread_info.h
new file mode 100644
index 000000000000..bff741ff337b
--- /dev/null
+++ b/arch/nds32/include/asm/thread_info.h
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#ifndef __ASM_NDS32_THREAD_INFO_H
+#define __ASM_NDS32_THREAD_INFO_H
+
+#ifdef __KERNEL__
+
+#define THREAD_SIZE_ORDER (1)
+#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
+
+#ifndef __ASSEMBLY__
+
+struct task_struct;
+
+#include <asm/ptrace.h>
+#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 */
+ __s32 preempt_count; /* 0 => preemptable, <0 => bug */
+ mm_segment_t addr_limit; /* address limit */
+};
+#define INIT_THREAD_INFO(tsk) \
+{ \
+ .preempt_count = INIT_PREEMPT_COUNT, \
+ .addr_limit = KERNEL_DS, \
+}
+#define thread_saved_pc(tsk) ((unsigned long)(tsk->thread.cpu_context.pc))
+#define thread_saved_fp(tsk) ((unsigned long)(tsk->thread.cpu_context.fp))
+#endif
+
+/*
+ * 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 1
+#define TIF_NEED_RESCHED 2
+#define TIF_SINGLESTEP 3
+#define TIF_NOTIFY_RESUME 4 /* callback before returning to user */
+#define TIF_SYSCALL_TRACE 8
+#define TIF_USEDFPU 16
+#define TIF_POLLING_NRFLAG 17
+#define TIF_MEMDIE 18
+#define TIF_FREEZE 19
+#define TIF_RESTORE_SIGMASK 20
+
+#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
+#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
+#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
+#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
+#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
+#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
+#define _TIF_FREEZE (1 << TIF_FREEZE)
+#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK)
+
+/*
+ * Change these and you break ASM code in entry-common.S
+ */
+#define _TIF_WORK_MASK 0x000000ff
+#define _TIF_WORK_SYSCALL_ENTRY (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP)
+#define _TIF_WORK_SYSCALL_LEAVE (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP)
+
+#endif /* __KERNEL__ */
+#endif /* __ASM_NDS32_THREAD_INFO_H */
diff --git a/arch/nds32/kernel/process.c b/arch/nds32/kernel/process.c
new file mode 100644
index 000000000000..65fda986e55f
--- /dev/null
+++ b/arch/nds32/kernel/process.c
@@ -0,0 +1,208 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/task_stack.h>
+#include <linux/delay.h>
+#include <linux/kallsyms.h>
+#include <linux/uaccess.h>
+#include <asm/elf.h>
+#include <asm/proc-fns.h>
+#include <linux/ptrace.h>
+#include <linux/reboot.h>
+
+extern void setup_mm_for_reboot(char mode);
+#ifdef CONFIG_PROC_FS
+struct proc_dir_entry *proc_dir_cpu;
+EXPORT_SYMBOL(proc_dir_cpu);
+#endif
+
+extern inline void arch_reset(char mode)
+{
+ if (mode == 's') {
+ /* Use cpu handler, jump to 0 */
+ cpu_reset(0);
+ }
+}
+
+void (*pm_power_off) (void);
+EXPORT_SYMBOL(pm_power_off);
+
+static char reboot_mode_nds32 = 'h';
+
+int __init reboot_setup(char *str)
+{
+ reboot_mode_nds32 = str[0];
+ return 1;
+}
+
+static int cpub_pwroff(void)
+{
+ return 0;
+}
+
+__setup("reboot=", reboot_setup);
+
+void machine_halt(void)
+{
+ cpub_pwroff();
+}
+
+EXPORT_SYMBOL(machine_halt);
+
+void machine_power_off(void)
+{
+ if (pm_power_off)
+ pm_power_off();
+}
+
+EXPORT_SYMBOL(machine_power_off);
+
+void machine_restart(char *cmd)
+{
+ /*
+ * Clean and disable cache, and turn off interrupts
+ */
+ cpu_proc_fin();
+
+ /*
+ * Tell the mm system that we are going to reboot -
+ * we may need it to insert some 1:1 mappings so that
+ * soft boot works.
+ */
+ setup_mm_for_reboot(reboot_mode_nds32);
+
+ /* Execute kernel restart handler call chain */
+ do_kernel_restart(cmd);
+
+ /*
+ * Now call the architecture specific reboot code.
+ */
+ arch_reset(reboot_mode_nds32);
+
+ /*
+ * Whoops - the architecture was unable to reboot.
+ * Tell the user!
+ */
+ mdelay(1000);
+ pr_info("Reboot failed -- System halted\n");
+ while (1) ;
+}
+
+EXPORT_SYMBOL(machine_restart);
+
+void show_regs(struct pt_regs *regs)
+{
+ printk("PC is at %pS\n", (void *)instruction_pointer(regs));
+ printk("LP is at %pS\n", (void *)regs->lp);
+ pr_info("pc : [<%08lx>] lp : [<%08lx>] %s\n"
+ "sp : %08lx fp : %08lx gp : %08lx\n",
+ instruction_pointer(regs),
+ regs->lp, print_tainted(), regs->sp, regs->fp, regs->gp);
+ pr_info("r25: %08lx r24: %08lx\n", regs->uregs[25], regs->uregs[24]);
+
+ pr_info("r23: %08lx r22: %08lx r21: %08lx r20: %08lx\n",
+ regs->uregs[23], regs->uregs[22],
+ regs->uregs[21], regs->uregs[20]);
+ pr_info("r19: %08lx r18: %08lx r17: %08lx r16: %08lx\n",
+ regs->uregs[19], regs->uregs[18],
+ regs->uregs[17], regs->uregs[16]);
+ pr_info("r15: %08lx r14: %08lx r13: %08lx r12: %08lx\n",
+ regs->uregs[15], regs->uregs[14],
+ regs->uregs[13], regs->uregs[12]);
+ pr_info("r11: %08lx r10: %08lx r9 : %08lx r8 : %08lx\n",
+ regs->uregs[11], regs->uregs[10],
+ regs->uregs[9], regs->uregs[8]);
+ pr_info("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
+ regs->uregs[7], regs->uregs[6], regs->uregs[5], regs->uregs[4]);
+ pr_info("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
+ regs->uregs[3], regs->uregs[2], regs->uregs[1], regs->uregs[0]);
+ pr_info(" IRQs o%s Segment %s\n",
+ interrupts_enabled(regs) ? "n" : "ff",
+ segment_eq(get_fs(), get_ds())? "kernel" : "user");
+}
+
+EXPORT_SYMBOL(show_regs);
+
+void flush_thread(void)
+{
+}
+
+DEFINE_PER_CPU(struct task_struct *, __entry_task);
+
+asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
+int copy_thread(unsigned long clone_flags, unsigned long stack_start,
+ unsigned long stk_sz, struct task_struct *p)
+{
+ struct pt_regs *childregs = task_pt_regs(p);
+
+ memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context));
+
+ if (unlikely(p->flags & PF_KTHREAD)) {
+ memset(childregs, 0, sizeof(struct pt_regs));
+ /* kernel thread fn */
+ p->thread.cpu_context.r6 = stack_start;
+ /* kernel thread argument */
+ p->thread.cpu_context.r7 = stk_sz;
+ } else {
+ *childregs = *current_pt_regs();
+ if (stack_start)
+ childregs->sp = stack_start;
+ /* child get zero as ret. */
+ childregs->uregs[0] = 0;
+ childregs->osp = 0;
+ if (clone_flags & CLONE_SETTLS)
+ childregs->uregs[25] = childregs->uregs[3];
+ }
+ /* cpu context switching */
+ p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
+ p->thread.cpu_context.sp = (unsigned long)childregs;
+
+#ifdef CONFIG_HWZOL
+ childregs->lb = 0;
+ childregs->le = 0;
+ childregs->lc = 0;
+#endif
+
+ return 0;
+}
+
+/*
+ * fill in the fpe structure for a core dump...
+ */
+int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpu)
+{
+ int fpvalid = 0;
+ return fpvalid;
+}
+
+EXPORT_SYMBOL(dump_fpu);
+
+unsigned long get_wchan(struct task_struct *p)
+{
+ unsigned long fp, lr;
+ unsigned long stack_start, stack_end;
+ int count = 0;
+
+ if (!p || p == current || p->state == TASK_RUNNING)
+ return 0;
+
+ if (IS_ENABLED(CONFIG_FRAME_POINTER)) {
+ stack_start = (unsigned long)end_of_stack(p);
+ stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;
+
+ fp = thread_saved_fp(p);
+ do {
+ if (fp < stack_start || fp > stack_end)
+ return 0;
+ lr = ((unsigned long *)fp)[0];
+ if (!in_sched_functions(lr))
+ return lr;
+ fp = *(unsigned long *)(fp + 4);
+ } while (count++ < 16);
+ }
+ return 0;
+}
+
+EXPORT_SYMBOL(get_wchan);
--
2.16.1
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