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metag: Scheduling/Process management 

Signed-off-by: James Hogan <james.hogan@imgtec.com>
This commit is contained in:
James Hogan 2012-10-09 10:54:54 +01:00
parent 26025bbfbb
commit 44dea393cf
2 changed files with 616 additions and 0 deletions
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155
arch/metag/include/asm/thread_info.h Normal file
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/* thread_info.h: Meta low-level thread information
*
* Copyright (C) 2002 David Howells (dhowells@redhat.com)
* - Incorporating suggestions made by Linus Torvalds and Dave Miller
*
* Meta port by Imagination Technologies
*/
#ifndef _ASM_THREAD_INFO_H
#define _ASM_THREAD_INFO_H
#include <linux/compiler.h>
#include <asm/page.h>
#ifndef __ASSEMBLY__
#include <asm/processor.h>
#endif
/*
* low level task data that entry.S needs immediate access to
* - this struct should fit entirely inside of one cache line
* - this struct shares the supervisor stack pages
* - if the contents of this structure are changed, the assembly constants must
* also be changed
*/
#ifndef __ASSEMBLY__
/* This must be 8 byte aligned so we can ensure stack alignment. */
struct thread_info {
struct task_struct *task; /* main task structure */
struct exec_domain *exec_domain; /* execution domain */
unsigned long flags; /* low level flags */
unsigned long status; /* thread-synchronous flags */
u32 cpu; /* current CPU */
int preempt_count; /* 0 => preemptable, <0 => BUG */
mm_segment_t addr_limit; /* thread address space */
struct restart_block restart_block;
u8 supervisor_stack[0];
};
#else /* !__ASSEMBLY__ */
#include <generated/asm-offsets.h>
#endif
#define PREEMPT_ACTIVE 0x10000000
#ifdef CONFIG_4KSTACKS
#define THREAD_SHIFT 12
#else
#define THREAD_SHIFT 13
#endif
#if THREAD_SHIFT >= PAGE_SHIFT
#define THREAD_SIZE_ORDER (THREAD_SHIFT - PAGE_SHIFT)
#else
#define THREAD_SIZE_ORDER 0
#endif
#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
#define STACK_WARN (THREAD_SIZE/8)
/*
* macros/functions for gaining access to the thread information structure
*/
#ifndef __ASSEMBLY__
#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)
/* how to get the current stack pointer from C */
register unsigned long current_stack_pointer asm("A0StP") __used;
/* how to get the thread information struct from C */
static inline struct thread_info *current_thread_info(void)
{
return (struct thread_info *)(current_stack_pointer &
~(THREAD_SIZE - 1));
}
#define __HAVE_ARCH_KSTACK_END
static inline int kstack_end(void *addr)
{
return addr == (void *) (((unsigned long) addr & ~(THREAD_SIZE - 1))
+ sizeof(struct thread_info));
}
#endif
/*
* 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_SIGPENDING 1 /* signal pending */
#define TIF_NEED_RESCHED 2 /* rescheduling necessary */
#define TIF_SINGLESTEP 3 /* restore singlestep on return to user
mode */
#define TIF_SYSCALL_AUDIT 4 /* syscall auditing active */
#define TIF_SECCOMP 5 /* secure computing */
#define TIF_RESTORE_SIGMASK 6 /* restore signal mask in do_signal() */
#define TIF_NOTIFY_RESUME 7 /* callback before returning to user */
#define TIF_POLLING_NRFLAG 8 /* true if poll_idle() is polling
TIF_NEED_RESCHED */
#define TIF_MEMDIE 9 /* is terminating due to OOM killer */
#define TIF_SYSCALL_TRACEPOINT 10 /* syscall tracepoint instrumentation */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
#define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP)
#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP (1<<TIF_SECCOMP)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
#define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK)
#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
/* work to do in syscall trace */
#define _TIF_WORK_SYSCALL_MASK (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP | \
_TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
_TIF_SYSCALL_TRACEPOINT)
/* work to do on any return to u-space */
#define _TIF_ALLWORK_MASK (_TIF_SYSCALL_TRACE | _TIF_SIGPENDING | \
_TIF_NEED_RESCHED | _TIF_SYSCALL_AUDIT | \
_TIF_SINGLESTEP | _TIF_RESTORE_SIGMASK | \
_TIF_NOTIFY_RESUME)
/* work to do on interrupt/exception return */
#define _TIF_WORK_MASK (_TIF_ALLWORK_MASK & ~(_TIF_SYSCALL_TRACE | \
_TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP))
#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
#endif /* _ASM_THREAD_INFO_H */

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arch/metag/kernel/process.c Normal file
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/*
* Copyright (C) 2005,2006,2007,2008,2009,2010,2011 Imagination Technologies
*
* This file contains the architecture-dependent parts of process handling.
*
*/
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/reboot.h>
#include <linux/elfcore.h>
#include <linux/fs.h>
#include <linux/tick.h>
#include <linux/slab.h>
#include <linux/mman.h>
#include <linux/pm.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include <asm/core_reg.h>
#include <asm/user_gateway.h>
#include <asm/tcm.h>
#include <asm/traps.h>
#include <asm/switch_to.h>
/*
* Wait for the next interrupt and enable local interrupts
*/
static inline void arch_idle(void)
{
int tmp;
/*
* Quickly jump straight into the interrupt entry point without actually
* triggering an interrupt. When TXSTATI gets read the processor will
* block until an interrupt is triggered.
*/
asm volatile (/* Switch into ISTAT mode */
"RTH\n\t"
/* Enable local interrupts */
"MOV TXMASKI, %1\n\t"
/*
* We can't directly "SWAP PC, PCX", so we swap via a
* temporary. Essentially we do:
* PCX_new = 1f (the place to continue execution)
* PC = PCX_old
*/
"ADD %0, CPC0, #(1f-.)\n\t"
"SWAP PCX, %0\n\t"
"MOV PC, %0\n"
/* Continue execution here with interrupts enabled */
"1:"
: "=a" (tmp)
: "r" (get_trigger_mask()));
}
void cpu_idle(void)
{
set_thread_flag(TIF_POLLING_NRFLAG);
while (1) {
tick_nohz_idle_enter();
rcu_idle_enter();
while (!need_resched()) {
/*
* We need to disable interrupts here to ensure we don't
* miss a wakeup call.
*/
local_irq_disable();
if (!need_resched()) {
#ifdef CONFIG_HOTPLUG_CPU
if (cpu_is_offline(smp_processor_id()))
cpu_die();
#endif
arch_idle();
} else {
local_irq_enable();
}
}
rcu_idle_exit();
tick_nohz_idle_exit();
schedule_preempt_disabled();
}
}
void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);
void (*soc_restart)(char *cmd);
void (*soc_halt)(void);
void machine_restart(char *cmd)
{
if (soc_restart)
soc_restart(cmd);
hard_processor_halt(HALT_OK);
}
void machine_halt(void)
{
if (soc_halt)
soc_halt();
smp_send_stop();
hard_processor_halt(HALT_OK);
}
void machine_power_off(void)
{
if (pm_power_off)
pm_power_off();
smp_send_stop();
hard_processor_halt(HALT_OK);
}
#define FLAG_Z 0x8
#define FLAG_N 0x4
#define FLAG_O 0x2
#define FLAG_C 0x1
void show_regs(struct pt_regs *regs)
{
int i;
const char *AX0_names[] = {"A0StP", "A0FrP"};
const char *AX1_names[] = {"A1GbP", "A1LbP"};
const char *DX0_names[] = {
"D0Re0",
"D0Ar6",
"D0Ar4",
"D0Ar2",
"D0FrT",
"D0.5 ",
"D0.6 ",
"D0.7 "
};
const char *DX1_names[] = {
"D1Re0",
"D1Ar5",
"D1Ar3",
"D1Ar1",
"D1RtP",
"D1.5 ",
"D1.6 ",
"D1.7 "
};
pr_info(" pt_regs @ %p\n", regs);
pr_info(" SaveMask = 0x%04hx\n", regs->ctx.SaveMask);
pr_info(" Flags = 0x%04hx (%c%c%c%c)\n", regs->ctx.Flags,
regs->ctx.Flags & FLAG_Z ? 'Z' : 'z',
regs->ctx.Flags & FLAG_N ? 'N' : 'n',
regs->ctx.Flags & FLAG_O ? 'O' : 'o',
regs->ctx.Flags & FLAG_C ? 'C' : 'c');
pr_info(" TXRPT = 0x%08x\n", regs->ctx.CurrRPT);
pr_info(" PC = 0x%08x\n", regs->ctx.CurrPC);
/* AX regs */
for (i = 0; i < 2; i++) {
pr_info(" %s = 0x%08x ",
AX0_names[i],
regs->ctx.AX[i].U0);
printk(" %s = 0x%08x\n",
AX1_names[i],
regs->ctx.AX[i].U1);
}
if (regs->ctx.SaveMask & TBICTX_XEXT_BIT)
pr_warn(" Extended state present - AX2.[01] will be WRONG\n");
/* Special place with AXx.2 */
pr_info(" A0.2 = 0x%08x ",
regs->ctx.Ext.AX2.U0);
printk(" A1.2 = 0x%08x\n",
regs->ctx.Ext.AX2.U1);
/* 'extended' AX regs (nominally, just AXx.3) */
for (i = 0; i < (TBICTX_AX_REGS - 3); i++) {
pr_info(" A0.%d = 0x%08x ", i + 3, regs->ctx.AX3[i].U0);
printk(" A1.%d = 0x%08x\n", i + 3, regs->ctx.AX3[i].U1);
}
for (i = 0; i < 8; i++) {
pr_info(" %s = 0x%08x ", DX0_names[i], regs->ctx.DX[i].U0);
printk(" %s = 0x%08x\n", DX1_names[i], regs->ctx.DX[i].U1);
}
show_trace(NULL, (unsigned long *)regs->ctx.AX[0].U0, regs);
}
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long arg, struct task_struct *tsk)
{
struct pt_regs *childregs = task_pt_regs(tsk);
void *kernel_context = ((void *) childregs +
sizeof(struct pt_regs));
unsigned long global_base;
BUG_ON(((unsigned long)childregs) & 0x7);
BUG_ON(((unsigned long)kernel_context) & 0x7);
memset(&tsk->thread.kernel_context, 0,
sizeof(tsk->thread.kernel_context));
tsk->thread.kernel_context = __TBISwitchInit(kernel_context,
ret_from_fork,
0, 0);
if (unlikely(tsk->flags & PF_KTHREAD)) {
/*
* Make sure we don't leak any kernel data to child's regs
* if kernel thread becomes a userspace thread in the future
*/
memset(childregs, 0 , sizeof(struct pt_regs));
global_base = __core_reg_get(A1GbP);
childregs->ctx.AX[0].U1 = (unsigned long) global_base;
childregs->ctx.AX[0].U0 = (unsigned long) kernel_context;
/* Set D1Ar1=arg and D1RtP=usp (fn) */
childregs->ctx.DX[4].U1 = usp;
childregs->ctx.DX[3].U1 = arg;
tsk->thread.int_depth = 2;
return 0;
}
/*
* Get a pointer to where the new child's register block should have
* been pushed.
* The Meta's stack grows upwards, and the context is the the first
* thing to be pushed by TBX (phew)
*/
*childregs = *current_pt_regs();
/* Set the correct stack for the clone mode */
if (usp)
childregs->ctx.AX[0].U0 = ALIGN(usp, 8);
tsk->thread.int_depth = 1;
/* set return value for child process */
childregs->ctx.DX[0].U0 = 0;
/* The TLS pointer is passed as an argument to sys_clone. */
if (clone_flags & CLONE_SETTLS)
tsk->thread.tls_ptr =
(__force void __user *)childregs->ctx.DX[1].U1;
#ifdef CONFIG_METAG_FPU
if (tsk->thread.fpu_context) {
struct meta_fpu_context *ctx;
ctx = kmemdup(tsk->thread.fpu_context,
sizeof(struct meta_fpu_context), GFP_ATOMIC);
tsk->thread.fpu_context = ctx;
}
#endif
#ifdef CONFIG_METAG_DSP
if (tsk->thread.dsp_context) {
struct meta_ext_context *ctx;
int i;
ctx = kmemdup(tsk->thread.dsp_context,
sizeof(struct meta_ext_context), GFP_ATOMIC);
for (i = 0; i < 2; i++)
ctx->ram[i] = kmemdup(ctx->ram[i], ctx->ram_sz[i],
GFP_ATOMIC);
tsk->thread.dsp_context = ctx;
}
#endif
return 0;
}
#ifdef CONFIG_METAG_FPU
static void alloc_fpu_context(struct thread_struct *thread)
{
thread->fpu_context = kzalloc(sizeof(struct meta_fpu_context),
GFP_ATOMIC);
}
static void clear_fpu(struct thread_struct *thread)
{
thread->user_flags &= ~TBICTX_FPAC_BIT;
kfree(thread->fpu_context);
thread->fpu_context = NULL;
}
#else
static void clear_fpu(struct thread_struct *thread)
{
}
#endif
#ifdef CONFIG_METAG_DSP
static void clear_dsp(struct thread_struct *thread)
{
if (thread->dsp_context) {
kfree(thread->dsp_context->ram[0]);
kfree(thread->dsp_context->ram[1]);
kfree(thread->dsp_context);
thread->dsp_context = NULL;
}
__core_reg_set(D0.8, 0);
}
#else
static void clear_dsp(struct thread_struct *thread)
{
}
#endif
struct task_struct *__sched __switch_to(struct task_struct *prev,
struct task_struct *next)
{
TBIRES to, from;
to.Switch.pCtx = next->thread.kernel_context;
to.Switch.pPara = prev;
#ifdef CONFIG_METAG_FPU
if (prev->thread.user_flags & TBICTX_FPAC_BIT) {
struct pt_regs *regs = task_pt_regs(prev);
TBIRES state;
state.Sig.SaveMask = prev->thread.user_flags;
state.Sig.pCtx = &regs->ctx;
if (!prev->thread.fpu_context)
alloc_fpu_context(&prev->thread);
if (prev->thread.fpu_context)
__TBICtxFPUSave(state, prev->thread.fpu_context);
}
/*
* Force a restore of the FPU context next time this process is
* scheduled.
*/
if (prev->thread.fpu_context)
prev->thread.fpu_context->needs_restore = true;
#endif
from = __TBISwitch(to, &prev->thread.kernel_context);
/* Restore TLS pointer for this process. */
set_gateway_tls(current->thread.tls_ptr);
return (struct task_struct *) from.Switch.pPara;
}
void flush_thread(void)
{
clear_fpu(&current->thread);
clear_dsp(&current->thread);
}
/*
* Free current thread data structures etc.
*/
void exit_thread(void)
{
clear_fpu(&current->thread);
clear_dsp(&current->thread);
}
/* TODO: figure out how to unwind the kernel stack here to figure out
* where we went to sleep. */
unsigned long get_wchan(struct task_struct *p)
{
return 0;
}
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
{
/* Returning 0 indicates that the FPU state was not stored (as it was
* not in use) */
return 0;
}
#ifdef CONFIG_METAG_USER_TCM
#define ELF_MIN_ALIGN PAGE_SIZE
#define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
#define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
#define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
unsigned long __metag_elf_map(struct file *filep, unsigned long addr,
struct elf_phdr *eppnt, int prot, int type,
unsigned long total_size)
{
unsigned long map_addr, size;
unsigned long page_off = ELF_PAGEOFFSET(eppnt->p_vaddr);
unsigned long raw_size = eppnt->p_filesz + page_off;
unsigned long off = eppnt->p_offset - page_off;
unsigned int tcm_tag;
addr = ELF_PAGESTART(addr);
size = ELF_PAGEALIGN(raw_size);
/* mmap() will return -EINVAL if given a zero size, but a
* segment with zero filesize is perfectly valid */
if (!size)
return addr;
tcm_tag = tcm_lookup_tag(addr);
if (tcm_tag != TCM_INVALID_TAG)
type &= ~MAP_FIXED;
/*
* total_size is the size of the ELF (interpreter) image.
* The _first_ mmap needs to know the full size, otherwise
* randomization might put this image into an overlapping
* position with the ELF binary image. (since size < total_size)
* So we first map the 'big' image - and unmap the remainder at
* the end. (which unmap is needed for ELF images with holes.)
*/
if (total_size) {
total_size = ELF_PAGEALIGN(total_size);
map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
if (!BAD_ADDR(map_addr))
vm_munmap(map_addr+size, total_size-size);
} else
map_addr = vm_mmap(filep, addr, size, prot, type, off);
if (!BAD_ADDR(map_addr) && tcm_tag != TCM_INVALID_TAG) {
struct tcm_allocation *tcm;
unsigned long tcm_addr;
tcm = kmalloc(sizeof(*tcm), GFP_KERNEL);
if (!tcm)
return -ENOMEM;
tcm_addr = tcm_alloc(tcm_tag, raw_size);
if (tcm_addr != addr) {
kfree(tcm);
return -ENOMEM;
}
tcm->tag = tcm_tag;
tcm->addr = tcm_addr;
tcm->size = raw_size;
list_add(&tcm->list, &current->mm->context.tcm);
eppnt->p_vaddr = map_addr;
if (copy_from_user((void *) addr, (void __user *) map_addr,
raw_size))
return -EFAULT;
}
return map_addr;
}
#endif