]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - arch/x86/kernel/process_64.c
x86, fpu: lazy allocation of FPU area - v5
[linux-2.6-omap-h63xx.git] / arch / x86 / kernel / process_64.c
index 137a86171c393ac64fd0e6df392d40caad951b9f..891af1a1b48a5cbf0ef303d9f1b5c5601b485869 100644 (file)
@@ -26,7 +26,6 @@
 #include <linux/smp.h>
 #include <linux/slab.h>
 #include <linux/user.h>
-#include <linux/a.out.h>
 #include <linux/interrupt.h>
 #include <linux/utsname.h>
 #include <linux/delay.h>
@@ -37,6 +36,7 @@
 #include <linux/kprobes.h>
 #include <linux/kdebug.h>
 #include <linux/tick.h>
+#include <linux/prctl.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -64,7 +64,6 @@ EXPORT_SYMBOL(boot_option_idle_override);
  */
 void (*pm_idle)(void);
 EXPORT_SYMBOL(pm_idle);
-static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
 
 static ATOMIC_NOTIFIER_HEAD(idle_notifier);
 
@@ -109,16 +108,8 @@ void default_idle(void)
        smp_mb();
        local_irq_disable();
        if (!need_resched()) {
-               ktime_t t0, t1;
-               u64 t0n, t1n;
-
-               t0 = ktime_get();
-               t0n = ktime_to_ns(t0);
                safe_halt();    /* enables interrupts racelessly */
                local_irq_disable();
-               t1 = ktime_get();
-               t1n = ktime_to_ns(t1);
-               sched_clock_idle_wakeup_event(t1n - t0n);
        }
        local_irq_enable();
        current_thread_info()->status |= TS_POLLING;
@@ -174,9 +165,6 @@ void cpu_idle(void)
                while (!need_resched()) {
                        void (*idle)(void);
 
-                       if (__get_cpu_var(cpu_idle_state))
-                               __get_cpu_var(cpu_idle_state) = 0;
-
                        rmb();
                        idle = pm_idle;
                        if (!idle)
@@ -208,40 +196,19 @@ static void do_nothing(void *unused)
 {
 }
 
+/*
+ * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
+ * pm_idle and update to new pm_idle value. Required while changing pm_idle
+ * handler on SMP systems.
+ *
+ * Caller must have changed pm_idle to the new value before the call. Old
+ * pm_idle value will not be used by any CPU after the return of this function.
+ */
 void cpu_idle_wait(void)
 {
-       unsigned int cpu, this_cpu = get_cpu();
-       cpumask_t map, tmp = current->cpus_allowed;
-
-       set_cpus_allowed(current, cpumask_of_cpu(this_cpu));
-       put_cpu();
-
-       cpus_clear(map);
-       for_each_online_cpu(cpu) {
-               per_cpu(cpu_idle_state, cpu) = 1;
-               cpu_set(cpu, map);
-       }
-
-       __get_cpu_var(cpu_idle_state) = 0;
-
-       wmb();
-       do {
-               ssleep(1);
-               for_each_online_cpu(cpu) {
-                       if (cpu_isset(cpu, map) && !per_cpu(cpu_idle_state, cpu))
-                               cpu_clear(cpu, map);
-               }
-               cpus_and(map, map, cpu_online_map);
-               /*
-                * We waited 1 sec, if a CPU still did not call idle
-                * it may be because it is in idle and not waking up
-                * because it has nothing to do.
-                * Give all the remaining CPUS a kick.
-                */
-               smp_call_function_mask(map, do_nothing, 0, 0);
-       } while (!cpus_empty(map));
-
-       set_cpus_allowed(current, tmp);
+       smp_mb();
+       /* kick all the CPUs so that they exit out of pm_idle */
+       smp_call_function(do_nothing, NULL, 0, 1);
 }
 EXPORT_SYMBOL_GPL(cpu_idle_wait);
 
@@ -554,6 +521,83 @@ out:
        return err;
 }
 
+void
+start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
+{
+       asm volatile("movl %0, %%fs; movl %0, %%es; movl %0, %%ds" :: "r"(0));
+       load_gs_index(0);
+       regs->ip                = new_ip;
+       regs->sp                = new_sp;
+       write_pda(oldrsp, new_sp);
+       regs->cs                = __USER_CS;
+       regs->ss                = __USER_DS;
+       regs->flags             = 0x200;
+       set_fs(USER_DS);
+       /*
+        * Free the old FP and other extended state
+        */
+       free_thread_xstate(current);
+}
+EXPORT_SYMBOL_GPL(start_thread);
+
+static void hard_disable_TSC(void)
+{
+       write_cr4(read_cr4() | X86_CR4_TSD);
+}
+
+void disable_TSC(void)
+{
+       preempt_disable();
+       if (!test_and_set_thread_flag(TIF_NOTSC))
+               /*
+                * Must flip the CPU state synchronously with
+                * TIF_NOTSC in the current running context.
+                */
+               hard_disable_TSC();
+       preempt_enable();
+}
+
+static void hard_enable_TSC(void)
+{
+       write_cr4(read_cr4() & ~X86_CR4_TSD);
+}
+
+void enable_TSC(void)
+{
+       preempt_disable();
+       if (test_and_clear_thread_flag(TIF_NOTSC))
+               /*
+                * Must flip the CPU state synchronously with
+                * TIF_NOTSC in the current running context.
+                */
+               hard_enable_TSC();
+       preempt_enable();
+}
+
+int get_tsc_mode(unsigned long adr)
+{
+       unsigned int val;
+
+       if (test_thread_flag(TIF_NOTSC))
+               val = PR_TSC_SIGSEGV;
+       else
+               val = PR_TSC_ENABLE;
+
+       return put_user(val, (unsigned int __user *)adr);
+}
+
+int set_tsc_mode(unsigned int val)
+{
+       if (val == PR_TSC_SIGSEGV)
+               disable_TSC();
+       else if (val == PR_TSC_ENABLE)
+               enable_TSC();
+       else
+               return -EINVAL;
+
+       return 0;
+}
+
 /*
  * This special macro can be used to load a debugging register
  */
@@ -574,12 +618,12 @@ static inline void __switch_to_xtra(struct task_struct *prev_p,
                /* we clear debugctl to make sure DS
                 * is not in use when we change it */
                debugctl = 0;
-               wrmsrl(MSR_IA32_DEBUGCTLMSR, 0);
+               update_debugctlmsr(0);
                wrmsrl(MSR_IA32_DS_AREA, next->ds_area_msr);
        }
 
        if (next->debugctlmsr != debugctl)
-               wrmsrl(MSR_IA32_DEBUGCTLMSR, next->debugctlmsr);
+               update_debugctlmsr(next->debugctlmsr);
 
        if (test_tsk_thread_flag(next_p, TIF_DEBUG)) {
                loaddebug(next, 0);
@@ -591,6 +635,15 @@ static inline void __switch_to_xtra(struct task_struct *prev_p,
                loaddebug(next, 7);
        }
 
+       if (test_tsk_thread_flag(prev_p, TIF_NOTSC) ^
+           test_tsk_thread_flag(next_p, TIF_NOTSC)) {
+               /* prev and next are different */
+               if (test_tsk_thread_flag(next_p, TIF_NOTSC))
+                       hard_disable_TSC();
+               else
+                       hard_enable_TSC();
+       }
+
        if (test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) {
                /*
                 * Copy the relevant range of the IO bitmap.
@@ -605,11 +658,13 @@ static inline void __switch_to_xtra(struct task_struct *prev_p,
                memset(tss->io_bitmap, 0xff, prev->io_bitmap_max);
        }
 
+#ifdef X86_BTS
        if (test_tsk_thread_flag(prev_p, TIF_BTS_TRACE_TS))
                ptrace_bts_take_timestamp(prev_p, BTS_TASK_DEPARTS);
 
        if (test_tsk_thread_flag(next_p, TIF_BTS_TRACE_TS))
                ptrace_bts_take_timestamp(next_p, BTS_TASK_ARRIVES);
+#endif
 }
 
 /*
@@ -631,7 +686,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 
        /* we're going to use this soon, after a few expensive things */
        if (next_p->fpu_counter>5)
-               prefetch(&next->i387.fxsave);
+               prefetch(next->xstate);
 
        /*
         * Reload esp0, LDT and the page table pointer:
@@ -731,16 +786,16 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
  */
 asmlinkage
 long sys_execve(char __user *name, char __user * __user *argv,
-               char __user * __user *envp, struct pt_regs regs)
+               char __user * __user *envp, struct pt_regs *regs)
 {
        long error;
        char * filename;
 
        filename = getname(name);
        error = PTR_ERR(filename);
-       if (IS_ERR(filename)) 
+       if (IS_ERR(filename))
                return error;
-       error = do_execve(filename, argv, envp, &regs); 
+       error = do_execve(filename, argv, envp, regs);
        putname(filename);
        return error;
 }