powerpc/cpumask: Update some comments
[safe/jmp/linux-2.6] / arch / powerpc / kernel / process.c
index ea6ad7a..9d255b4 100644 (file)
 #include <linux/mqueue.h>
 #include <linux/hardirq.h>
 #include <linux/utsname.h>
+#include <linux/ftrace.h>
+#include <linux/kernel_stat.h>
+#include <linux/personality.h>
+#include <linux/random.h>
 
 #include <asm/pgtable.h>
 #include <asm/uaccess.h>
 #ifdef CONFIG_PPC64
 #include <asm/firmware.h>
 #endif
+#include <linux/kprobes.h>
+#include <linux/kdebug.h>
 
 extern unsigned long _get_SP(void);
 
 #ifndef CONFIG_SMP
 struct task_struct *last_task_used_math = NULL;
 struct task_struct *last_task_used_altivec = NULL;
+struct task_struct *last_task_used_vsx = NULL;
 struct task_struct *last_task_used_spe = NULL;
 #endif
 
@@ -104,17 +111,6 @@ void enable_kernel_fp(void)
 }
 EXPORT_SYMBOL(enable_kernel_fp);
 
-int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs)
-{
-       if (!tsk->thread.regs)
-               return 0;
-       flush_fp_to_thread(current);
-
-       memcpy(fpregs, &tsk->thread.fpr[0], sizeof(*fpregs));
-
-       return 1;
-}
-
 #ifdef CONFIG_ALTIVEC
 void enable_kernel_altivec(void)
 {
@@ -148,36 +144,48 @@ void flush_altivec_to_thread(struct task_struct *tsk)
                preempt_enable();
        }
 }
+#endif /* CONFIG_ALTIVEC */
 
-int dump_task_altivec(struct task_struct *tsk, elf_vrregset_t *vrregs)
+#ifdef CONFIG_VSX
+#if 0
+/* not currently used, but some crazy RAID module might want to later */
+void enable_kernel_vsx(void)
 {
-       /* ELF_NVRREG includes the VSCR and VRSAVE which we need to save
-        * separately, see below */
-       const int nregs = ELF_NVRREG - 2;
-       elf_vrreg_t *reg;
-       u32 *dest;
-
-       if (tsk == current)
-               flush_altivec_to_thread(tsk);
-
-       reg = (elf_vrreg_t *)vrregs;
-
-       /* copy the 32 vr registers */
-       memcpy(reg, &tsk->thread.vr[0], nregs * sizeof(*reg));
-       reg += nregs;
+       WARN_ON(preemptible());
 
-       /* copy the vscr */
-       memcpy(reg, &tsk->thread.vscr, sizeof(*reg));
-       reg++;
+#ifdef CONFIG_SMP
+       if (current->thread.regs && (current->thread.regs->msr & MSR_VSX))
+               giveup_vsx(current);
+       else
+               giveup_vsx(NULL);       /* just enable vsx for kernel - force */
+#else
+       giveup_vsx(last_task_used_vsx);
+#endif /* CONFIG_SMP */
+}
+EXPORT_SYMBOL(enable_kernel_vsx);
+#endif
 
-       /* vrsave is stored in the high 32bit slot of the final 128bits */
-       memset(reg, 0, sizeof(*reg));
-       dest = (u32 *)reg;
-       *dest = tsk->thread.vrsave;
+void giveup_vsx(struct task_struct *tsk)
+{
+       giveup_fpu(tsk);
+       giveup_altivec(tsk);
+       __giveup_vsx(tsk);
+}
 
-       return 1;
+void flush_vsx_to_thread(struct task_struct *tsk)
+{
+       if (tsk->thread.regs) {
+               preempt_disable();
+               if (tsk->thread.regs->msr & MSR_VSX) {
+#ifdef CONFIG_SMP
+                       BUG_ON(tsk != current);
+#endif
+                       giveup_vsx(tsk);
+               }
+               preempt_enable();
+       }
 }
-#endif /* CONFIG_ALTIVEC */
+#endif /* CONFIG_VSX */
 
 #ifdef CONFIG_SPE
 
@@ -209,14 +217,6 @@ void flush_spe_to_thread(struct task_struct *tsk)
                preempt_enable();
        }
 }
-
-int dump_spe(struct pt_regs *regs, elf_vrregset_t *evrregs)
-{
-       flush_spe_to_thread(current);
-       /* We copy u32 evr[32] + u64 acc + u32 spefscr -> 35 */
-       memcpy(evrregs, &current->thread.evr[0], sizeof(u32) * 35);
-       return 1;
-}
 #endif /* CONFIG_SPE */
 
 #ifndef CONFIG_SMP
@@ -233,6 +233,10 @@ void discard_lazy_cpu_state(void)
        if (last_task_used_altivec == current)
                last_task_used_altivec = NULL;
 #endif /* CONFIG_ALTIVEC */
+#ifdef CONFIG_VSX
+       if (last_task_used_vsx == current)
+               last_task_used_vsx = NULL;
+#endif /* CONFIG_VSX */
 #ifdef CONFIG_SPE
        if (last_task_used_spe == current)
                last_task_used_spe = NULL;
@@ -241,17 +245,140 @@ void discard_lazy_cpu_state(void)
 }
 #endif /* CONFIG_SMP */
 
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+void do_send_trap(struct pt_regs *regs, unsigned long address,
+                 unsigned long error_code, int signal_code, int breakpt)
+{
+       siginfo_t info;
+
+       if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
+                       11, SIGSEGV) == NOTIFY_STOP)
+               return;
+
+       /* Deliver the signal to userspace */
+       info.si_signo = SIGTRAP;
+       info.si_errno = breakpt;        /* breakpoint or watchpoint id */
+       info.si_code = signal_code;
+       info.si_addr = (void __user *)address;
+       force_sig_info(SIGTRAP, &info, current);
+}
+#else  /* !CONFIG_PPC_ADV_DEBUG_REGS */
+void do_dabr(struct pt_regs *regs, unsigned long address,
+                   unsigned long error_code)
+{
+       siginfo_t info;
+
+       if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
+                       11, SIGSEGV) == NOTIFY_STOP)
+               return;
+
+       if (debugger_dabr_match(regs))
+               return;
+
+       /* Clear the DABR */
+       set_dabr(0);
+
+       /* Deliver the signal to userspace */
+       info.si_signo = SIGTRAP;
+       info.si_errno = 0;
+       info.si_code = TRAP_HWBKPT;
+       info.si_addr = (void __user *)address;
+       force_sig_info(SIGTRAP, &info, current);
+}
+#endif /* CONFIG_PPC_ADV_DEBUG_REGS */
+
+static DEFINE_PER_CPU(unsigned long, current_dabr);
+
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+/*
+ * Set the debug registers back to their default "safe" values.
+ */
+static void set_debug_reg_defaults(struct thread_struct *thread)
+{
+       thread->iac1 = thread->iac2 = 0;
+#if CONFIG_PPC_ADV_DEBUG_IACS > 2
+       thread->iac3 = thread->iac4 = 0;
+#endif
+       thread->dac1 = thread->dac2 = 0;
+#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
+       thread->dvc1 = thread->dvc2 = 0;
+#endif
+       thread->dbcr0 = 0;
+#ifdef CONFIG_BOOKE
+       /*
+        * Force User/Supervisor bits to b11 (user-only MSR[PR]=1)
+        */
+       thread->dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US |   \
+                       DBCR1_IAC3US | DBCR1_IAC4US;
+       /*
+        * Force Data Address Compare User/Supervisor bits to be User-only
+        * (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0.
+        */
+       thread->dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US;
+#else
+       thread->dbcr1 = 0;
+#endif
+}
+
+static void prime_debug_regs(struct thread_struct *thread)
+{
+       mtspr(SPRN_IAC1, thread->iac1);
+       mtspr(SPRN_IAC2, thread->iac2);
+#if CONFIG_PPC_ADV_DEBUG_IACS > 2
+       mtspr(SPRN_IAC3, thread->iac3);
+       mtspr(SPRN_IAC4, thread->iac4);
+#endif
+       mtspr(SPRN_DAC1, thread->dac1);
+       mtspr(SPRN_DAC2, thread->dac2);
+#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
+       mtspr(SPRN_DVC1, thread->dvc1);
+       mtspr(SPRN_DVC2, thread->dvc2);
+#endif
+       mtspr(SPRN_DBCR0, thread->dbcr0);
+       mtspr(SPRN_DBCR1, thread->dbcr1);
+#ifdef CONFIG_BOOKE
+       mtspr(SPRN_DBCR2, thread->dbcr2);
+#endif
+}
+/*
+ * Unless neither the old or new thread are making use of the
+ * debug registers, set the debug registers from the values
+ * stored in the new thread.
+ */
+static void switch_booke_debug_regs(struct thread_struct *new_thread)
+{
+       if ((current->thread.dbcr0 & DBCR0_IDM)
+               || (new_thread->dbcr0 & DBCR0_IDM))
+                       prime_debug_regs(new_thread);
+}
+#else  /* !CONFIG_PPC_ADV_DEBUG_REGS */
+static void set_debug_reg_defaults(struct thread_struct *thread)
+{
+       if (thread->dabr) {
+               thread->dabr = 0;
+               set_dabr(0);
+       }
+}
+#endif /* CONFIG_PPC_ADV_DEBUG_REGS */
+
 int set_dabr(unsigned long dabr)
 {
-#ifdef CONFIG_PPC_MERGE                /* XXX for now */
+       __get_cpu_var(current_dabr) = dabr;
+
        if (ppc_md.set_dabr)
                return ppc_md.set_dabr(dabr);
-#endif
 
        /* XXX should we have a CPU_FTR_HAS_DABR ? */
-#if defined(CONFIG_PPC64) || defined(CONFIG_6xx)
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+       mtspr(SPRN_DAC1, dabr);
+#ifdef CONFIG_PPC_47x
+       isync();
+#endif
+#elif defined(CONFIG_PPC_BOOK3S)
        mtspr(SPRN_DABR, dabr);
 #endif
+
+
        return 0;
 }
 
@@ -259,8 +386,6 @@ int set_dabr(unsigned long dabr)
 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
 #endif
 
-static DEFINE_PER_CPU(unsigned long, current_dabr);
-
 struct task_struct *__switch_to(struct task_struct *prev,
        struct task_struct *new)
 {
@@ -295,6 +420,11 @@ struct task_struct *__switch_to(struct task_struct *prev,
        if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC))
                giveup_altivec(prev);
 #endif /* CONFIG_ALTIVEC */
+#ifdef CONFIG_VSX
+       if (prev->thread.regs && (prev->thread.regs->msr & MSR_VSX))
+               /* VMX and FPU registers are already save here */
+               __giveup_vsx(prev);
+#endif /* CONFIG_VSX */
 #ifdef CONFIG_SPE
        /*
         * If the previous thread used spe in the last quantum
@@ -315,6 +445,10 @@ struct task_struct *__switch_to(struct task_struct *prev,
        if (new->thread.regs && last_task_used_altivec == new)
                new->thread.regs->msr |= MSR_VEC;
 #endif /* CONFIG_ALTIVEC */
+#ifdef CONFIG_VSX
+       if (new->thread.regs && last_task_used_vsx == new)
+               new->thread.regs->msr |= MSR_VSX;
+#endif /* CONFIG_VSX */
 #ifdef CONFIG_SPE
        /* Avoid the trap.  On smp this this never happens since
         * we don't set last_task_used_spe
@@ -325,10 +459,13 @@ struct task_struct *__switch_to(struct task_struct *prev,
 
 #endif /* CONFIG_SMP */
 
-       if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) {
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+       switch_booke_debug_regs(&new->thread);
+#else
+       if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr))
                set_dabr(new->thread.dabr);
-               __get_cpu_var(current_dabr) = new->thread.dabr;
-       }
+#endif
+
 
        new_thread = &new->thread;
        old_thread = &current->thread;
@@ -353,6 +490,12 @@ struct task_struct *__switch_to(struct task_struct *prev,
        account_process_vtime(current);
        calculate_steal_time();
 
+       /*
+        * We can't take a PMU exception inside _switch() since there is a
+        * window where the kernel stack SLB and the kernel stack are out
+        * of sync. Hard disable here.
+        */
+       hard_irq_disable();
        last = _switch(old_thread, new_thread);
 
        local_irq_restore(flags);
@@ -411,7 +554,11 @@ static struct regbit {
        {MSR_EE,        "EE"},
        {MSR_PR,        "PR"},
        {MSR_FP,        "FP"},
+       {MSR_VEC,       "VEC"},
+       {MSR_VSX,       "VSX"},
        {MSR_ME,        "ME"},
+       {MSR_CE,        "CE"},
+       {MSR_DE,        "DE"},
        {MSR_IR,        "IR"},
        {MSR_DR,        "DR"},
        {0,             NULL}
@@ -453,21 +600,21 @@ void show_regs(struct pt_regs * regs)
        printk("  CR: %08lx  XER: %08lx\n", regs->ccr, regs->xer);
        trap = TRAP(regs);
        if (trap == 0x300 || trap == 0x600)
-#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
                printk("DEAR: "REG", ESR: "REG"\n", regs->dar, regs->dsisr);
 #else
                printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr);
 #endif
        printk("TASK = %p[%d] '%s' THREAD: %p",
-              current, current->pid, current->comm, task_thread_info(current));
+              current, task_pid_nr(current), current->comm, task_thread_info(current));
 
 #ifdef CONFIG_SMP
-       printk(" CPU: %d", smp_processor_id());
+       printk(" CPU: %d", raw_smp_processor_id());
 #endif /* CONFIG_SMP */
 
        for (i = 0;  i < 32;  i++) {
                if ((i % REGS_PER_LINE) == 0)
-                       printk("\n" KERN_INFO "GPR%02d: ", i);
+                       printk("\nGPR%02d: ", i);
                printk(REG " ", regs->gpr[i]);
                if (i == LAST_VOLATILE && !FULL_REGS(regs))
                        break;
@@ -478,10 +625,8 @@ void show_regs(struct pt_regs * regs)
         * Lookup NIP late so we have the best change of getting the
         * above info out without failing
         */
-       printk("NIP ["REG"] ", regs->nip);
-       print_symbol("%s\n", regs->nip);
-       printk("LR ["REG"] ", regs->link);
-       print_symbol("%s\n", regs->link);
+       printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip);
+       printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link);
 #endif
        show_stack(current, (unsigned long *) regs->gpr[1]);
        if (!user_mode(regs))
@@ -495,24 +640,9 @@ void exit_thread(void)
 
 void flush_thread(void)
 {
-#ifdef CONFIG_PPC64
-       struct thread_info *t = current_thread_info();
-
-       if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
-               clear_ti_thread_flag(t, TIF_ABI_PENDING);
-               if (test_ti_thread_flag(t, TIF_32BIT))
-                       clear_ti_thread_flag(t, TIF_32BIT);
-               else
-                       set_ti_thread_flag(t, TIF_32BIT);
-       }
-#endif
-
        discard_lazy_cpu_state();
 
-       if (current->thread.dabr) {
-               current->thread.dabr = 0;
-               set_dabr(0);
-       }
+       set_debug_reg_defaults(&current->thread);
 }
 
 void
@@ -528,13 +658,14 @@ void prepare_to_copy(struct task_struct *tsk)
 {
        flush_fp_to_thread(current);
        flush_altivec_to_thread(current);
+       flush_vsx_to_thread(current);
        flush_spe_to_thread(current);
 }
 
 /*
  * Copy a thread..
  */
-int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
+int copy_thread(unsigned long clone_flags, unsigned long usp,
                unsigned long unused, struct task_struct *p,
                struct pt_regs *regs)
 {
@@ -583,8 +714,10 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
        kregs = (struct pt_regs *) sp;
        sp -= STACK_FRAME_OVERHEAD;
        p->thread.ksp = sp;
+       p->thread.ksp_limit = (unsigned long)task_stack_page(p) +
+                               _ALIGN_UP(sizeof(struct thread_info), 16);
 
-#ifdef CONFIG_PPC64
+#ifdef CONFIG_PPC_STD_MMU_64
        if (cpu_has_feature(CPU_FTR_SLB)) {
                unsigned long sp_vsid;
                unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
@@ -598,6 +731,7 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
                sp_vsid |= SLB_VSID_KERNEL | llp;
                p->thread.ksp_vsid = sp_vsid;
        }
+#endif /* CONFIG_PPC_STD_MMU_64 */
 
        /*
         * The PPC64 ABI makes use of a TOC to contain function 
@@ -605,6 +739,7 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
         * to the TOC entry.  The first entry is a pointer to the actual
         * function.
         */
+#ifdef CONFIG_PPC64
        kregs->nip = *((unsigned long *)ret_from_fork);
 #else
        kregs->nip = (unsigned long)ret_from_fork;
@@ -681,6 +816,9 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
 #endif
 
        discard_lazy_cpu_state();
+#ifdef CONFIG_VSX
+       current->thread.used_vsr = 0;
+#endif
        memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
        current->thread.fpscr.val = 0;
 #ifdef CONFIG_ALTIVEC
@@ -862,11 +1000,6 @@ int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
        flush_spe_to_thread(current);
        error = do_execve(filename, (char __user * __user *) a1,
                          (char __user * __user *) a2, regs);
-       if (error == 0) {
-               task_lock(current);
-               current->ptrace &= ~PT_DTRACE;
-               task_unlock(current);
-       }
        putname(filename);
 out:
        return error;
@@ -913,20 +1046,6 @@ int validate_sp(unsigned long sp, struct task_struct *p,
        return valid_irq_stack(sp, p, nbytes);
 }
 
-#ifdef CONFIG_PPC64
-#define MIN_STACK_FRAME        112     /* same as STACK_FRAME_OVERHEAD, in fact */
-#define FRAME_LR_SAVE  2
-#define INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD + 288)
-#define REGS_MARKER    0x7265677368657265ul
-#define FRAME_MARKER   12
-#else
-#define MIN_STACK_FRAME        16
-#define FRAME_LR_SAVE  1
-#define INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
-#define REGS_MARKER    0x72656773ul
-#define FRAME_MARKER   2
-#endif
-
 EXPORT_SYMBOL(validate_sp);
 
 unsigned long get_wchan(struct task_struct *p)
@@ -938,15 +1057,15 @@ unsigned long get_wchan(struct task_struct *p)
                return 0;
 
        sp = p->thread.ksp;
-       if (!validate_sp(sp, p, MIN_STACK_FRAME))
+       if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
                return 0;
 
        do {
                sp = *(unsigned long *)sp;
-               if (!validate_sp(sp, p, MIN_STACK_FRAME))
+               if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
                        return 0;
                if (count > 0) {
-                       ip = ((unsigned long *)sp)[FRAME_LR_SAVE];
+                       ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE];
                        if (!in_sched_functions(ip))
                                return ip;
                }
@@ -954,13 +1073,25 @@ unsigned long get_wchan(struct task_struct *p)
        return 0;
 }
 
-static int kstack_depth_to_print = 64;
+static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH;
 
 void show_stack(struct task_struct *tsk, unsigned long *stack)
 {
        unsigned long sp, ip, lr, newsp;
        int count = 0;
        int firstframe = 1;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+       int curr_frame = current->curr_ret_stack;
+       extern void return_to_handler(void);
+       unsigned long rth = (unsigned long)return_to_handler;
+       unsigned long mrth = -1;
+#ifdef CONFIG_PPC64
+       extern void mod_return_to_handler(void);
+       rth = *(unsigned long *)rth;
+       mrth = (unsigned long)mod_return_to_handler;
+       mrth = *(unsigned long *)mrth;
+#endif
+#endif
 
        sp = (unsigned long) stack;
        if (tsk == NULL)
@@ -975,15 +1106,21 @@ void show_stack(struct task_struct *tsk, unsigned long *stack)
        lr = 0;
        printk("Call Trace:\n");
        do {
-               if (!validate_sp(sp, tsk, MIN_STACK_FRAME))
+               if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
                        return;
 
                stack = (unsigned long *) sp;
                newsp = stack[0];
-               ip = stack[FRAME_LR_SAVE];
+               ip = stack[STACK_FRAME_LR_SAVE];
                if (!firstframe || ip != lr) {
-                       printk("["REG"] ["REG"] ", sp, ip);
-                       print_symbol("%s", ip);
+                       printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+                       if ((ip == rth || ip == mrth) && curr_frame >= 0) {
+                               printk(" (%pS)",
+                                      (void *)current->ret_stack[curr_frame].ret);
+                               curr_frame--;
+                       }
+#endif
                        if (firstframe)
                                printk(" (unreliable)");
                        printk("\n");
@@ -994,14 +1131,13 @@ void show_stack(struct task_struct *tsk, unsigned long *stack)
                 * See if this is an exception frame.
                 * We look for the "regshere" marker in the current frame.
                 */
-               if (validate_sp(sp, tsk, INT_FRAME_SIZE)
-                   && stack[FRAME_MARKER] == REGS_MARKER) {
+               if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE)
+                   && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
                        struct pt_regs *regs = (struct pt_regs *)
                                (sp + STACK_FRAME_OVERHEAD);
-                       printk("--- Exception: %lx", regs->trap);
-                       print_symbol(" at %s\n", regs->nip);
                        lr = regs->link;
-                       print_symbol("    LR = %s\n", lr);
+                       printk("--- Exception: %lx at %pS\n    LR = %pS\n",
+                              regs->trap, (void *)regs->nip, (void *)lr);
                        firstframe = 1;
                }
 
@@ -1046,3 +1182,89 @@ void ppc64_runlatch_off(void)
        }
 }
 #endif
+
+#if THREAD_SHIFT < PAGE_SHIFT
+
+static struct kmem_cache *thread_info_cache;
+
+struct thread_info *alloc_thread_info(struct task_struct *tsk)
+{
+       struct thread_info *ti;
+
+       ti = kmem_cache_alloc(thread_info_cache, GFP_KERNEL);
+       if (unlikely(ti == NULL))
+               return NULL;
+#ifdef CONFIG_DEBUG_STACK_USAGE
+       memset(ti, 0, THREAD_SIZE);
+#endif
+       return ti;
+}
+
+void free_thread_info(struct thread_info *ti)
+{
+       kmem_cache_free(thread_info_cache, ti);
+}
+
+void thread_info_cache_init(void)
+{
+       thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE,
+                                             THREAD_SIZE, 0, NULL);
+       BUG_ON(thread_info_cache == NULL);
+}
+
+#endif /* THREAD_SHIFT < PAGE_SHIFT */
+
+unsigned long arch_align_stack(unsigned long sp)
+{
+       if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
+               sp -= get_random_int() & ~PAGE_MASK;
+       return sp & ~0xf;
+}
+
+static inline unsigned long brk_rnd(void)
+{
+        unsigned long rnd = 0;
+
+       /* 8MB for 32bit, 1GB for 64bit */
+       if (is_32bit_task())
+               rnd = (long)(get_random_int() % (1<<(23-PAGE_SHIFT)));
+       else
+               rnd = (long)(get_random_int() % (1<<(30-PAGE_SHIFT)));
+
+       return rnd << PAGE_SHIFT;
+}
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+       unsigned long base = mm->brk;
+       unsigned long ret;
+
+#ifdef CONFIG_PPC_STD_MMU_64
+       /*
+        * If we are using 1TB segments and we are allowed to randomise
+        * the heap, we can put it above 1TB so it is backed by a 1TB
+        * segment. Otherwise the heap will be in the bottom 1TB
+        * which always uses 256MB segments and this may result in a
+        * performance penalty.
+        */
+       if (!is_32bit_task() && (mmu_highuser_ssize == MMU_SEGSIZE_1T))
+               base = max_t(unsigned long, mm->brk, 1UL << SID_SHIFT_1T);
+#endif
+
+       ret = PAGE_ALIGN(base + brk_rnd());
+
+       if (ret < mm->brk)
+               return mm->brk;
+
+       return ret;
+}
+
+unsigned long randomize_et_dyn(unsigned long base)
+{
+       unsigned long ret = PAGE_ALIGN(base + brk_rnd());
+
+       if (ret < base)
+               return base;
+
+       return ret;
+}