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authorMark Salter2012-09-21 11:26:37 -0500
committerAl Viro2012-09-30 23:59:08 -0500
commit46f15067c020a0ce712cb2d3ef38c0589a521c15 (patch)
treef980e4faf9dccc1be052fdbbb1dbd785c6238cc6 /arch/c6x
parent61b7fbc3f4ebdcfd34f9438adfab8df936a19e33 (diff)
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c6x: add ret_from_kernel_thread(), simplify kernel_thread()
Signed-off-by: Mark Salter <msalter@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/c6x')
-rw-r--r--arch/c6x/kernel/entry.S20
-rw-r--r--arch/c6x/kernel/process.c38
2 files changed, 32 insertions, 26 deletions
diff --git a/arch/c6x/kernel/entry.S b/arch/c6x/kernel/entry.S
index 30b37e5f4a6..6e6bd9d3d9c 100644
--- a/arch/c6x/kernel/entry.S
+++ b/arch/c6x/kernel/entry.S
@@ -400,6 +400,26 @@ ret_from_fork_2:
400 STW .D2T2 B0,*+SP(REGS_A4+8) 400 STW .D2T2 B0,*+SP(REGS_A4+8)
401ENDPROC(ret_from_fork) 401ENDPROC(ret_from_fork)
402 402
403ENTRY(ret_from_kernel_thread)
404#ifdef CONFIG_C6X_BIG_KERNEL
405 MVKL .S1 schedule_tail,A0
406 MVKH .S1 schedule_tail,A0
407 B .S2X A0
408#else
409 B .S2 schedule_tail
410#endif
411 LDW .D2T2 *+SP(REGS_A0+8),B10 /* get fn */
412 ADDKPC .S2 0f,B3,3
4130:
414 B .S2 B10 /* call fn */
415 LDW .D2T1 *+SP(REGS_A1+8),A4 /* get arg */
416 MVKL .S2 sys_exit,B11
417 MVKH .S2 sys_exit,B11
418 ADDKPC .S2 0f,B3,1
4190:
420 BNOP .S2 B11,5 /* jump to sys_exit */
421ENDPROC(ret_from_kernel_thread)
422
403 ;; 423 ;;
404 ;; These are the interrupt handlers, responsible for calling __do_IRQ() 424 ;; These are the interrupt handlers, responsible for calling __do_IRQ()
405 ;; int6 is used for syscalls (see _system_call entry) 425 ;; int6 is used for syscalls (see _system_call entry)
diff --git a/arch/c6x/kernel/process.c b/arch/c6x/kernel/process.c
index 45e924a636a..d2ffc9bdaba 100644
--- a/arch/c6x/kernel/process.c
+++ b/arch/c6x/kernel/process.c
@@ -25,6 +25,7 @@ void (*c6x_restart)(void);
25void (*c6x_halt)(void); 25void (*c6x_halt)(void);
26 26
27extern asmlinkage void ret_from_fork(void); 27extern asmlinkage void ret_from_fork(void);
28extern asmlinkage void ret_from_kernel_thread(void);
28 29
29/* 30/*
30 * power off function, if any 31 * power off function, if any
@@ -103,36 +104,21 @@ void machine_power_off(void)
103 halt_loop(); 104 halt_loop();
104} 105}
105 106
106static void kernel_thread_helper(int dummy, void *arg, int (*fn)(void *))
107{
108 do_exit(fn(arg));
109}
110
111/* 107/*
112 * Create a kernel thread 108 * Create a kernel thread
113 */ 109 */
114int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 110int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
115{ 111{
116 struct pt_regs regs; 112 struct pt_regs regs = {
117 113 .a0 = (unsigned long)fn,
118 /* 114 .a1 = (unsigned long)arg,
119 * copy_thread sets a4 to zero (child return from fork) 115 .tsr = 0, /* kernel mode */
120 * so we can't just set things up to directly return to 116 };
121 * fn.
122 */
123 memset(&regs, 0, sizeof(regs));
124 regs.b4 = (unsigned long) arg;
125 regs.a6 = (unsigned long) fn;
126 regs.pc = (unsigned long) kernel_thread_helper;
127 local_save_flags(regs.csr);
128 regs.csr |= 1;
129 regs.tsr = 5; /* Set GEE and GIE in TSR */
130 117
131 /* Ok, create the new process.. */ 118 /* Ok, create the new process.. */
132 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, -1, &regs, 119 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, -1, &regs,
133 0, NULL, NULL); 120 0, NULL, NULL);
134} 121}
135EXPORT_SYMBOL(kernel_thread);
136 122
137void flush_thread(void) 123void flush_thread(void)
138{ 124{
@@ -192,21 +178,21 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
192 childregs = task_pt_regs(p); 178 childregs = task_pt_regs(p);
193 179
194 *childregs = *regs; 180 *childregs = *regs;
195 childregs->a4 = 0;
196 181
197 if (usp == -1) 182 if (usp == -1) {
198 /* case of __kernel_thread: we return to supervisor space */ 183 /* case of __kernel_thread: we return to supervisor space */
199 childregs->sp = (unsigned long)(childregs + 1); 184 childregs->sp = (unsigned long)(childregs + 1);
200 else 185 p->thread.pc = (unsigned long) ret_from_kernel_thread;
186 } else {
201 /* Otherwise use the given stack */ 187 /* Otherwise use the given stack */
202 childregs->sp = usp; 188 childregs->sp = usp;
189 p->thread.pc = (unsigned long) ret_from_fork;
190 }
203 191
204 /* Set usp/ksp */ 192 /* Set usp/ksp */
205 p->thread.usp = childregs->sp; 193 p->thread.usp = childregs->sp;
206 /* switch_to uses stack to save/restore 14 callee-saved regs */
207 thread_saved_ksp(p) = (unsigned long)childregs - 8; 194 thread_saved_ksp(p) = (unsigned long)childregs - 8;
208 p->thread.pc = (unsigned int) ret_from_fork; 195 p->thread.wchan = p->thread.pc;
209 p->thread.wchan = (unsigned long) ret_from_fork;
210#ifdef __DSBT__ 196#ifdef __DSBT__
211 { 197 {
212 unsigned long dp; 198 unsigned long dp;