1efe4ce3ca
This implements kernel-level atomic rollback built on top of gUSA, as an alternative non-IRQ based atomicity method. This is generally a faster method for platforms that are lacking the LL/SC pairs that SH-4A and later use, and is only supportable on legacy cores. Signed-off-by: Stuart Menefy <stuart.menefy@st.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
466 lines
10 KiB
C
466 lines
10 KiB
C
/*
|
|
* arch/sh/kernel/process.c
|
|
*
|
|
* This file handles the architecture-dependent parts of process handling..
|
|
*
|
|
* Copyright (C) 1995 Linus Torvalds
|
|
*
|
|
* SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
|
|
* Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC
|
|
* Copyright (C) 2002 - 2007 Paul Mundt
|
|
*/
|
|
#include <linux/module.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/elfcore.h>
|
|
#include <linux/pm.h>
|
|
#include <linux/kallsyms.h>
|
|
#include <linux/kexec.h>
|
|
#include <linux/kdebug.h>
|
|
#include <linux/tick.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/preempt.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/mmu_context.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/system.h>
|
|
#include <asm/ubc.h>
|
|
|
|
static int hlt_counter;
|
|
int ubc_usercnt = 0;
|
|
|
|
void (*pm_idle)(void);
|
|
void (*pm_power_off)(void);
|
|
EXPORT_SYMBOL(pm_power_off);
|
|
|
|
void disable_hlt(void)
|
|
{
|
|
hlt_counter++;
|
|
}
|
|
EXPORT_SYMBOL(disable_hlt);
|
|
|
|
void enable_hlt(void)
|
|
{
|
|
hlt_counter--;
|
|
}
|
|
EXPORT_SYMBOL(enable_hlt);
|
|
|
|
static int __init nohlt_setup(char *__unused)
|
|
{
|
|
hlt_counter = 1;
|
|
return 1;
|
|
}
|
|
__setup("nohlt", nohlt_setup);
|
|
|
|
static int __init hlt_setup(char *__unused)
|
|
{
|
|
hlt_counter = 0;
|
|
return 1;
|
|
}
|
|
__setup("hlt", hlt_setup);
|
|
|
|
void default_idle(void)
|
|
{
|
|
if (!hlt_counter) {
|
|
clear_thread_flag(TIF_POLLING_NRFLAG);
|
|
smp_mb__after_clear_bit();
|
|
set_bl_bit();
|
|
while (!need_resched())
|
|
cpu_sleep();
|
|
clear_bl_bit();
|
|
set_thread_flag(TIF_POLLING_NRFLAG);
|
|
} else
|
|
while (!need_resched())
|
|
cpu_relax();
|
|
}
|
|
|
|
void cpu_idle(void)
|
|
{
|
|
set_thread_flag(TIF_POLLING_NRFLAG);
|
|
|
|
/* endless idle loop with no priority at all */
|
|
while (1) {
|
|
void (*idle)(void) = pm_idle;
|
|
|
|
if (!idle)
|
|
idle = default_idle;
|
|
|
|
tick_nohz_stop_sched_tick();
|
|
while (!need_resched())
|
|
idle();
|
|
tick_nohz_restart_sched_tick();
|
|
|
|
preempt_enable_no_resched();
|
|
schedule();
|
|
preempt_disable();
|
|
check_pgt_cache();
|
|
}
|
|
}
|
|
|
|
void machine_restart(char * __unused)
|
|
{
|
|
/* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
|
|
asm volatile("ldc %0, sr\n\t"
|
|
"mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
|
|
}
|
|
|
|
void machine_halt(void)
|
|
{
|
|
local_irq_disable();
|
|
|
|
while (1)
|
|
cpu_sleep();
|
|
}
|
|
|
|
void machine_power_off(void)
|
|
{
|
|
if (pm_power_off)
|
|
pm_power_off();
|
|
}
|
|
|
|
void show_regs(struct pt_regs * regs)
|
|
{
|
|
printk("\n");
|
|
printk("Pid : %d, Comm: %20s\n", task_pid_nr(current), current->comm);
|
|
print_symbol("PC is at %s\n", instruction_pointer(regs));
|
|
printk("PC : %08lx SP : %08lx SR : %08lx ",
|
|
regs->pc, regs->regs[15], regs->sr);
|
|
#ifdef CONFIG_MMU
|
|
printk("TEA : %08x ", ctrl_inl(MMU_TEA));
|
|
#else
|
|
printk(" ");
|
|
#endif
|
|
printk("%s\n", print_tainted());
|
|
|
|
printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
|
|
regs->regs[0],regs->regs[1],
|
|
regs->regs[2],regs->regs[3]);
|
|
printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
|
|
regs->regs[4],regs->regs[5],
|
|
regs->regs[6],regs->regs[7]);
|
|
printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
|
|
regs->regs[8],regs->regs[9],
|
|
regs->regs[10],regs->regs[11]);
|
|
printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
|
|
regs->regs[12],regs->regs[13],
|
|
regs->regs[14]);
|
|
printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
|
|
regs->mach, regs->macl, regs->gbr, regs->pr);
|
|
|
|
show_trace(NULL, (unsigned long *)regs->regs[15], regs);
|
|
}
|
|
|
|
/*
|
|
* Create a kernel thread
|
|
*/
|
|
|
|
/*
|
|
* This is the mechanism for creating a new kernel thread.
|
|
*
|
|
*/
|
|
extern void kernel_thread_helper(void);
|
|
__asm__(".align 5\n"
|
|
"kernel_thread_helper:\n\t"
|
|
"jsr @r5\n\t"
|
|
" nop\n\t"
|
|
"mov.l 1f, r1\n\t"
|
|
"jsr @r1\n\t"
|
|
" mov r0, r4\n\t"
|
|
".align 2\n\t"
|
|
"1:.long do_exit");
|
|
|
|
/* Don't use this in BL=1(cli). Or else, CPU resets! */
|
|
int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
|
|
{
|
|
struct pt_regs regs;
|
|
|
|
memset(®s, 0, sizeof(regs));
|
|
regs.regs[4] = (unsigned long)arg;
|
|
regs.regs[5] = (unsigned long)fn;
|
|
|
|
regs.pc = (unsigned long)kernel_thread_helper;
|
|
regs.sr = (1 << 30);
|
|
|
|
/* Ok, create the new process.. */
|
|
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
|
|
®s, 0, NULL, NULL);
|
|
}
|
|
|
|
/*
|
|
* Free current thread data structures etc..
|
|
*/
|
|
void exit_thread(void)
|
|
{
|
|
if (current->thread.ubc_pc) {
|
|
current->thread.ubc_pc = 0;
|
|
ubc_usercnt -= 1;
|
|
}
|
|
}
|
|
|
|
void flush_thread(void)
|
|
{
|
|
#if defined(CONFIG_SH_FPU)
|
|
struct task_struct *tsk = current;
|
|
/* Forget lazy FPU state */
|
|
clear_fpu(tsk, task_pt_regs(tsk));
|
|
clear_used_math();
|
|
#endif
|
|
}
|
|
|
|
void release_thread(struct task_struct *dead_task)
|
|
{
|
|
/* do nothing */
|
|
}
|
|
|
|
/* Fill in the fpu structure for a core dump.. */
|
|
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
|
|
{
|
|
int fpvalid = 0;
|
|
|
|
#if defined(CONFIG_SH_FPU)
|
|
struct task_struct *tsk = current;
|
|
|
|
fpvalid = !!tsk_used_math(tsk);
|
|
if (fpvalid) {
|
|
unlazy_fpu(tsk, regs);
|
|
memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
|
|
}
|
|
#endif
|
|
|
|
return fpvalid;
|
|
}
|
|
|
|
asmlinkage void ret_from_fork(void);
|
|
|
|
int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
|
|
unsigned long unused,
|
|
struct task_struct *p, struct pt_regs *regs)
|
|
{
|
|
struct thread_info *ti = task_thread_info(p);
|
|
struct pt_regs *childregs;
|
|
#if defined(CONFIG_SH_FPU)
|
|
struct task_struct *tsk = current;
|
|
|
|
unlazy_fpu(tsk, regs);
|
|
p->thread.fpu = tsk->thread.fpu;
|
|
copy_to_stopped_child_used_math(p);
|
|
#endif
|
|
|
|
childregs = task_pt_regs(p);
|
|
*childregs = *regs;
|
|
|
|
if (user_mode(regs)) {
|
|
childregs->regs[15] = usp;
|
|
ti->addr_limit = USER_DS;
|
|
} else {
|
|
childregs->regs[15] = (unsigned long)childregs;
|
|
ti->addr_limit = KERNEL_DS;
|
|
}
|
|
|
|
if (clone_flags & CLONE_SETTLS)
|
|
childregs->gbr = childregs->regs[0];
|
|
|
|
childregs->regs[0] = 0; /* Set return value for child */
|
|
|
|
p->thread.sp = (unsigned long) childregs;
|
|
p->thread.pc = (unsigned long) ret_from_fork;
|
|
|
|
p->thread.ubc_pc = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Tracing by user break controller. */
|
|
static void ubc_set_tracing(int asid, unsigned long pc)
|
|
{
|
|
#if defined(CONFIG_CPU_SH4A)
|
|
unsigned long val;
|
|
|
|
val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE);
|
|
val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid));
|
|
|
|
ctrl_outl(val, UBC_CBR0);
|
|
ctrl_outl(pc, UBC_CAR0);
|
|
ctrl_outl(0x0, UBC_CAMR0);
|
|
ctrl_outl(0x0, UBC_CBCR);
|
|
|
|
val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE);
|
|
ctrl_outl(val, UBC_CRR0);
|
|
|
|
/* Read UBC register that we wrote last, for checking update */
|
|
val = ctrl_inl(UBC_CRR0);
|
|
|
|
#else /* CONFIG_CPU_SH4A */
|
|
ctrl_outl(pc, UBC_BARA);
|
|
|
|
#ifdef CONFIG_MMU
|
|
ctrl_outb(asid, UBC_BASRA);
|
|
#endif
|
|
|
|
ctrl_outl(0, UBC_BAMRA);
|
|
|
|
if (current_cpu_data.type == CPU_SH7729 ||
|
|
current_cpu_data.type == CPU_SH7710 ||
|
|
current_cpu_data.type == CPU_SH7712) {
|
|
ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA);
|
|
ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR);
|
|
} else {
|
|
ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA);
|
|
ctrl_outw(BRCR_PCBA, UBC_BRCR);
|
|
}
|
|
#endif /* CONFIG_CPU_SH4A */
|
|
}
|
|
|
|
/*
|
|
* switch_to(x,y) should switch tasks from x to y.
|
|
*
|
|
*/
|
|
struct task_struct *__switch_to(struct task_struct *prev,
|
|
struct task_struct *next)
|
|
{
|
|
#if defined(CONFIG_SH_FPU)
|
|
unlazy_fpu(prev, task_pt_regs(prev));
|
|
#endif
|
|
|
|
#ifdef CONFIG_MMU
|
|
/*
|
|
* Restore the kernel mode register
|
|
* k7 (r7_bank1)
|
|
*/
|
|
asm volatile("ldc %0, r7_bank"
|
|
: /* no output */
|
|
: "r" (task_thread_info(next)));
|
|
#endif
|
|
|
|
/* If no tasks are using the UBC, we're done */
|
|
if (ubc_usercnt == 0)
|
|
/* If no tasks are using the UBC, we're done */;
|
|
else if (next->thread.ubc_pc && next->mm) {
|
|
int asid = 0;
|
|
#ifdef CONFIG_MMU
|
|
asid |= cpu_asid(smp_processor_id(), next->mm);
|
|
#endif
|
|
ubc_set_tracing(asid, next->thread.ubc_pc);
|
|
} else {
|
|
#if defined(CONFIG_CPU_SH4A)
|
|
ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
|
|
ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
|
|
#else
|
|
ctrl_outw(0, UBC_BBRA);
|
|
ctrl_outw(0, UBC_BBRB);
|
|
#endif
|
|
}
|
|
|
|
return prev;
|
|
}
|
|
|
|
asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
|
|
unsigned long r6, unsigned long r7,
|
|
struct pt_regs __regs)
|
|
{
|
|
#ifdef CONFIG_MMU
|
|
struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
|
|
return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL);
|
|
#else
|
|
/* fork almost works, enough to trick you into looking elsewhere :-( */
|
|
return -EINVAL;
|
|
#endif
|
|
}
|
|
|
|
asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
|
|
unsigned long parent_tidptr,
|
|
unsigned long child_tidptr,
|
|
struct pt_regs __regs)
|
|
{
|
|
struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
|
|
if (!newsp)
|
|
newsp = regs->regs[15];
|
|
return do_fork(clone_flags, newsp, regs, 0,
|
|
(int __user *)parent_tidptr,
|
|
(int __user *)child_tidptr);
|
|
}
|
|
|
|
/*
|
|
* This is trivial, and on the face of it looks like it
|
|
* could equally well be done in user mode.
|
|
*
|
|
* Not so, for quite unobvious reasons - register pressure.
|
|
* In user mode vfork() cannot have a stack frame, and if
|
|
* done by calling the "clone()" system call directly, you
|
|
* do not have enough call-clobbered registers to hold all
|
|
* the information you need.
|
|
*/
|
|
asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
|
|
unsigned long r6, unsigned long r7,
|
|
struct pt_regs __regs)
|
|
{
|
|
struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
|
|
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs,
|
|
0, NULL, NULL);
|
|
}
|
|
|
|
/*
|
|
* sys_execve() executes a new program.
|
|
*/
|
|
asmlinkage int sys_execve(char __user *ufilename, char __user * __user *uargv,
|
|
char __user * __user *uenvp, unsigned long r7,
|
|
struct pt_regs __regs)
|
|
{
|
|
struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
|
|
int error;
|
|
char *filename;
|
|
|
|
filename = getname(ufilename);
|
|
error = PTR_ERR(filename);
|
|
if (IS_ERR(filename))
|
|
goto out;
|
|
|
|
error = do_execve(filename, uargv, uenvp, regs);
|
|
if (error == 0) {
|
|
task_lock(current);
|
|
current->ptrace &= ~PT_DTRACE;
|
|
task_unlock(current);
|
|
}
|
|
putname(filename);
|
|
out:
|
|
return error;
|
|
}
|
|
|
|
unsigned long get_wchan(struct task_struct *p)
|
|
{
|
|
unsigned long pc;
|
|
|
|
if (!p || p == current || p->state == TASK_RUNNING)
|
|
return 0;
|
|
|
|
/*
|
|
* The same comment as on the Alpha applies here, too ...
|
|
*/
|
|
pc = thread_saved_pc(p);
|
|
|
|
#ifdef CONFIG_FRAME_POINTER
|
|
if (in_sched_functions(pc)) {
|
|
unsigned long schedule_frame = (unsigned long)p->thread.sp;
|
|
return ((unsigned long *)schedule_frame)[21];
|
|
}
|
|
#endif
|
|
|
|
return pc;
|
|
}
|
|
|
|
asmlinkage void break_point_trap(void)
|
|
{
|
|
/* Clear tracing. */
|
|
#if defined(CONFIG_CPU_SH4A)
|
|
ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
|
|
ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
|
|
#else
|
|
ctrl_outw(0, UBC_BBRA);
|
|
ctrl_outw(0, UBC_BBRB);
|
|
#endif
|
|
current->thread.ubc_pc = 0;
|
|
ubc_usercnt -= 1;
|
|
|
|
force_sig(SIGTRAP, current);
|
|
}
|