]> nv-tegra.nvidia Code Review - linux-2.6.git/blobdiff - arch/x86/kernel/process_32.c
x86, fpu: lazy allocation of FPU area - v5
[linux-2.6.git] / arch / x86 / kernel / process_32.c
index a7d50a547dc2a8a1be9f2af87a52226d95c6438c..7adad088e373fbf4bf5523dcf70f22665331b105 100644 (file)
@@ -36,6 +36,7 @@
 #include <linux/personality.h>
 #include <linux/tick.h>
 #include <linux/percpu.h>
+#include <linux/prctl.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -45,7 +46,6 @@
 #include <asm/processor.h>
 #include <asm/i387.h>
 #include <asm/desc.h>
-#include <asm/vm86.h>
 #ifdef CONFIG_MATH_EMULATION
 #include <asm/math_emu.h>
 #endif
@@ -82,7 +82,6 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
  */
 void (*pm_idle)(void);
 EXPORT_SYMBOL(pm_idle);
-static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
 
 void disable_hlt(void)
 {
@@ -114,20 +113,13 @@ void default_idle(void)
 
                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;
        } else {
+               local_irq_enable();
                /* loop is done by the caller */
                cpu_relax();
        }
@@ -143,6 +135,7 @@ EXPORT_SYMBOL(default_idle);
  */
 static void poll_idle(void)
 {
+       local_irq_enable();
        cpu_relax();
 }
 
@@ -190,9 +183,6 @@ void cpu_idle(void)
                while (!need_resched()) {
                        void (*idle)(void);
 
-                       if (__get_cpu_var(cpu_idle_state))
-                               __get_cpu_var(cpu_idle_state) = 0;
-
                        check_pgt_cache();
                        rmb();
                        idle = pm_idle;
@@ -220,40 +210,19 @@ 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, NULL, 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);
 
@@ -273,8 +242,11 @@ void mwait_idle_with_hints(unsigned long ax, unsigned long cx)
                __monitor((void *)&current_thread_info()->flags, 0, 0);
                smp_mb();
                if (!need_resched())
-                       __mwait(ax, cx);
-       }
+                       __sti_mwait(ax, cx);
+               else
+                       local_irq_enable();
+       } else
+               local_irq_enable();
 }
 
 /* Default MONITOR/MWAIT with no hints, used for default C1 state */
@@ -357,7 +329,7 @@ void __show_registers(struct pt_regs *regs, int all)
                        init_utsname()->version);
 
        printk("EIP: %04x:[<%08lx>] EFLAGS: %08lx CPU: %d\n",
-                       0xffff & regs->cs, regs->ip, regs->flags,
+                       (u16)regs->cs, regs->ip, regs->flags,
                        smp_processor_id());
        print_symbol("EIP is at %s\n", regs->ip);
 
@@ -366,8 +338,7 @@ void __show_registers(struct pt_regs *regs, int all)
        printk("ESI: %08lx EDI: %08lx EBP: %08lx ESP: %08lx\n",
                regs->si, regs->di, regs->bp, sp);
        printk(" DS: %04x ES: %04x FS: %04x GS: %04x SS: %04x\n",
-              regs->ds & 0xffff, regs->es & 0xffff,
-              regs->fs & 0xffff, gs, ss);
+              (u16)regs->ds, (u16)regs->es, (u16)regs->fs, gs, ss);
 
        if (!all)
                return;
@@ -538,11 +509,30 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
        return err;
 }
 
-#ifdef CONFIG_SECCOMP
+void
+start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
+{
+       __asm__("movl %0, %%gs" :: "r"(0));
+       regs->fs                = 0;
+       set_fs(USER_DS);
+       regs->ds                = __USER_DS;
+       regs->es                = __USER_DS;
+       regs->ss                = __USER_DS;
+       regs->cs                = __USER_CS;
+       regs->ip                = new_ip;
+       regs->sp                = new_sp;
+       /*
+        * 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();
@@ -554,11 +544,47 @@ void disable_TSC(void)
                hard_disable_TSC();
        preempt_enable();
 }
+
 static void hard_enable_TSC(void)
 {
        write_cr4(read_cr4() & ~X86_CR4_TSD);
 }
-#endif /* CONFIG_SECCOMP */
+
+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;
+}
 
 static noinline void
 __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
@@ -575,12 +601,12 @@ __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_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);
                wrmsr(MSR_IA32_DS_AREA, next->ds_area_msr, 0);
        }
 
        if (next->debugctlmsr != debugctl)
-               wrmsr(MSR_IA32_DEBUGCTLMSR, next->debugctlmsr, 0);
+               update_debugctlmsr(next->debugctlmsr);
 
        if (test_tsk_thread_flag(next_p, TIF_DEBUG)) {
                set_debugreg(next->debugreg0, 0);
@@ -592,7 +618,6 @@ __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
                set_debugreg(next->debugreg7, 7);
        }
 
-#ifdef CONFIG_SECCOMP
        if (test_tsk_thread_flag(prev_p, TIF_NOTSC) ^
            test_tsk_thread_flag(next_p, TIF_NOTSC)) {
                /* prev and next are different */
@@ -601,13 +626,14 @@ __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
                else
                        hard_enable_TSC();
        }
-#endif
 
+#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
 
 
        if (!test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) {
@@ -681,7 +707,7 @@ struct task_struct * __switch_to(struct task_struct *prev_p, struct task_struct
 
        /* 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.