Contributors: 49
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Thomas Gleixner |
976 |
35.29% |
22 |
19.13% |
| Kyle Huey |
424 |
15.33% |
4 |
3.48% |
| Jeremy Fitzhardinge |
294 |
10.63% |
1 |
0.87% |
| Len Brown |
153 |
5.53% |
4 |
3.48% |
| Andrew Lutomirski |
143 |
5.17% |
11 |
9.57% |
| Peter Zijlstra |
100 |
3.62% |
3 |
2.61% |
| Tim Chen |
95 |
3.43% |
2 |
1.74% |
| Tom Lendacky |
60 |
2.17% |
3 |
2.61% |
| Américo Wang |
58 |
2.10% |
1 |
0.87% |
| Suresh B. Siddha |
45 |
1.63% |
3 |
2.61% |
| Waiman Long |
40 |
1.45% |
1 |
0.87% |
| Richard Weinberger |
35 |
1.27% |
1 |
0.87% |
| Ingo Molnar |
33 |
1.19% |
11 |
9.57% |
| Borislav Petkov |
32 |
1.16% |
3 |
2.61% |
| Ivan Vecera |
30 |
1.08% |
1 |
0.87% |
| Yakui Zhao |
27 |
0.98% |
2 |
1.74% |
| Thomas Renninger |
23 |
0.83% |
3 |
2.61% |
| Rusty Russell |
22 |
0.80% |
3 |
2.61% |
| Konrad Rzeszutek Wilk |
20 |
0.72% |
2 |
1.74% |
| Brian Gerst |
17 |
0.61% |
2 |
1.74% |
| JiSheng Zhang |
16 |
0.58% |
1 |
0.87% |
| Mike Galbraith |
14 |
0.51% |
1 |
0.87% |
| Ashok Raj |
12 |
0.43% |
1 |
0.87% |
| Joe Perches |
12 |
0.43% |
1 |
0.87% |
| Cyrill V. Gorcunov |
9 |
0.33% |
1 |
0.87% |
| Yi Wang |
9 |
0.33% |
1 |
0.87% |
| Andy Isaacson |
6 |
0.22% |
1 |
0.87% |
| Dave Hansen |
6 |
0.22% |
1 |
0.87% |
| Andi Kleen |
6 |
0.22% |
1 |
0.87% |
| K.Prasad |
5 |
0.18% |
1 |
0.87% |
| Jaswinder Singh Rajput |
5 |
0.18% |
2 |
1.74% |
| Avi Kivity |
4 |
0.14% |
2 |
1.74% |
| Jiri Slaby |
4 |
0.14% |
1 |
0.87% |
| Frédéric Weisbecker |
4 |
0.14% |
1 |
0.87% |
| Paul Gortmaker |
4 |
0.14% |
1 |
0.87% |
| Andrey Ryabinin |
3 |
0.11% |
1 |
0.87% |
| Arjan van de Ven |
3 |
0.11% |
2 |
1.74% |
| Jason Cooper |
2 |
0.07% |
1 |
0.87% |
| Michael S. Tsirkin |
2 |
0.07% |
1 |
0.87% |
| Andy Whitcroft |
2 |
0.07% |
1 |
0.87% |
| Chris Metcalf |
2 |
0.07% |
1 |
0.87% |
| Steven Rostedt |
2 |
0.07% |
1 |
0.87% |
| Marc Dionne |
1 |
0.04% |
1 |
0.87% |
| Greg Kroah-Hartman |
1 |
0.04% |
1 |
0.87% |
| Huang Rui |
1 |
0.04% |
1 |
0.87% |
| Linus Torvalds |
1 |
0.04% |
1 |
0.87% |
| Oleg Nesterov |
1 |
0.04% |
1 |
0.87% |
| Nadav Amit |
1 |
0.04% |
1 |
0.87% |
| Nick Desaulniers |
1 |
0.04% |
1 |
0.87% |
| Total |
2766 |
|
115 |
|
// SPDX-License-Identifier: GPL-2.0
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/prctl.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/sched/idle.h>
#include <linux/sched/debug.h>
#include <linux/sched/task.h>
#include <linux/sched/task_stack.h>
#include <linux/init.h>
#include <linux/export.h>
#include <linux/pm.h>
#include <linux/tick.h>
#include <linux/random.h>
#include <linux/user-return-notifier.h>
#include <linux/dmi.h>
#include <linux/utsname.h>
#include <linux/stackprotector.h>
#include <linux/cpuidle.h>
#include <linux/acpi.h>
#include <linux/elf-randomize.h>
#include <trace/events/power.h>
#include <linux/hw_breakpoint.h>
#include <asm/cpu.h>
#include <asm/apic.h>
#include <asm/syscalls.h>
#include <linux/uaccess.h>
#include <asm/mwait.h>
#include <asm/fpu/internal.h>
#include <asm/debugreg.h>
#include <asm/nmi.h>
#include <asm/tlbflush.h>
#include <asm/mce.h>
#include <asm/vm86.h>
#include <asm/switch_to.h>
#include <asm/desc.h>
#include <asm/prctl.h>
#include <asm/spec-ctrl.h>
#include <asm/proto.h>
#include "process.h"
/*
* per-CPU TSS segments. Threads are completely 'soft' on Linux,
* no more per-task TSS's. The TSS size is kept cacheline-aligned
* so they are allowed to end up in the .data..cacheline_aligned
* section. Since TSS's are completely CPU-local, we want them
* on exact cacheline boundaries, to eliminate cacheline ping-pong.
*/
__visible DEFINE_PER_CPU_PAGE_ALIGNED(struct tss_struct, cpu_tss_rw) = {
.x86_tss = {
/*
* .sp0 is only used when entering ring 0 from a lower
* privilege level. Since the init task never runs anything
* but ring 0 code, there is no need for a valid value here.
* Poison it.
*/
.sp0 = (1UL << (BITS_PER_LONG-1)) + 1,
/*
* .sp1 is cpu_current_top_of_stack. The init task never
* runs user code, but cpu_current_top_of_stack should still
* be well defined before the first context switch.
*/
.sp1 = TOP_OF_INIT_STACK,
#ifdef CONFIG_X86_32
.ss0 = __KERNEL_DS,
.ss1 = __KERNEL_CS,
.io_bitmap_base = INVALID_IO_BITMAP_OFFSET,
#endif
},
#ifdef CONFIG_X86_32
/*
* Note that the .io_bitmap member must be extra-big. This is because
* the CPU will access an additional byte beyond the end of the IO
* permission bitmap. The extra byte must be all 1 bits, and must
* be within the limit.
*/
.io_bitmap = { [0 ... IO_BITMAP_LONGS] = ~0 },
#endif
};
EXPORT_PER_CPU_SYMBOL(cpu_tss_rw);
DEFINE_PER_CPU(bool, __tss_limit_invalid);
EXPORT_PER_CPU_SYMBOL_GPL(__tss_limit_invalid);
/*
* this gets called so that we can store lazy state into memory and copy the
* current task into the new thread.
*/
int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
{
memcpy(dst, src, arch_task_struct_size);
#ifdef CONFIG_VM86
dst->thread.vm86 = NULL;
#endif
return fpu__copy(dst, src);
}
/*
* Free current thread data structures etc..
*/
void exit_thread(struct task_struct *tsk)
{
struct thread_struct *t = &tsk->thread;
unsigned long *bp = t->io_bitmap_ptr;
struct fpu *fpu = &t->fpu;
if (bp) {
struct tss_struct *tss = &per_cpu(cpu_tss_rw, get_cpu());
t->io_bitmap_ptr = NULL;
clear_thread_flag(TIF_IO_BITMAP);
/*
* Careful, clear this in the TSS too:
*/
memset(tss->io_bitmap, 0xff, t->io_bitmap_max);
t->io_bitmap_max = 0;
put_cpu();
kfree(bp);
}
free_vm86(t);
fpu__drop(fpu);
}
void flush_thread(void)
{
struct task_struct *tsk = current;
flush_ptrace_hw_breakpoint(tsk);
memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));
fpu__clear(&tsk->thread.fpu);
}
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.
*/
cr4_set_bits(X86_CR4_TSD);
preempt_enable();
}
static 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.
*/
cr4_clear_bits(X86_CR4_TSD);
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;
}
DEFINE_PER_CPU(u64, msr_misc_features_shadow);
static void set_cpuid_faulting(bool on)
{
u64 msrval;
msrval = this_cpu_read(msr_misc_features_shadow);
msrval &= ~MSR_MISC_FEATURES_ENABLES_CPUID_FAULT;
msrval |= (on << MSR_MISC_FEATURES_ENABLES_CPUID_FAULT_BIT);
this_cpu_write(msr_misc_features_shadow, msrval);
wrmsrl(MSR_MISC_FEATURES_ENABLES, msrval);
}
static void disable_cpuid(void)
{
preempt_disable();
if (!test_and_set_thread_flag(TIF_NOCPUID)) {
/*
* Must flip the CPU state synchronously with
* TIF_NOCPUID in the current running context.
*/
set_cpuid_faulting(true);
}
preempt_enable();
}
static void enable_cpuid(void)
{
preempt_disable();
if (test_and_clear_thread_flag(TIF_NOCPUID)) {
/*
* Must flip the CPU state synchronously with
* TIF_NOCPUID in the current running context.
*/
set_cpuid_faulting(false);
}
preempt_enable();
}
static int get_cpuid_mode(void)
{
return !test_thread_flag(TIF_NOCPUID);
}
static int set_cpuid_mode(struct task_struct *task, unsigned long cpuid_enabled)
{
if (!boot_cpu_has(X86_FEATURE_CPUID_FAULT))
return -ENODEV;
if (cpuid_enabled)
enable_cpuid();
else
disable_cpuid();
return 0;
}
/*
* Called immediately after a successful exec.
*/
void arch_setup_new_exec(void)
{
/* If cpuid was previously disabled for this task, re-enable it. */
if (test_thread_flag(TIF_NOCPUID))
enable_cpuid();
/*
* Don't inherit TIF_SSBD across exec boundary when
* PR_SPEC_DISABLE_NOEXEC is used.
*/
if (test_thread_flag(TIF_SSBD) &&
task_spec_ssb_noexec(current)) {
clear_thread_flag(TIF_SSBD);
task_clear_spec_ssb_disable(current);
task_clear_spec_ssb_noexec(current);
speculation_ctrl_update(task_thread_info(current)->flags);
}
}
static inline void switch_to_bitmap(struct thread_struct *prev,
struct thread_struct *next,
unsigned long tifp, unsigned long tifn)
{
struct tss_struct *tss = this_cpu_ptr(&cpu_tss_rw);
if (tifn & _TIF_IO_BITMAP) {
/*
* Copy the relevant range of the IO bitmap.
* Normally this is 128 bytes or less:
*/
memcpy(tss->io_bitmap, next->io_bitmap_ptr,
max(prev->io_bitmap_max, next->io_bitmap_max));
/*
* Make sure that the TSS limit is correct for the CPU
* to notice the IO bitmap.
*/
refresh_tss_limit();
} else if (tifp & _TIF_IO_BITMAP) {
/*
* Clear any possible leftover bits:
*/
memset(tss->io_bitmap, 0xff, prev->io_bitmap_max);
}
}
#ifdef CONFIG_SMP
struct ssb_state {
struct ssb_state *shared_state;
raw_spinlock_t lock;
unsigned int disable_state;
unsigned long local_state;
};
#define LSTATE_SSB 0
static DEFINE_PER_CPU(struct ssb_state, ssb_state);
void speculative_store_bypass_ht_init(void)
{
struct ssb_state *st = this_cpu_ptr(&ssb_state);
unsigned int this_cpu = smp_processor_id();
unsigned int cpu;
st->local_state = 0;
/*
* Shared state setup happens once on the first bringup
* of the CPU. It's not destroyed on CPU hotunplug.
*/
if (st->shared_state)
return;
raw_spin_lock_init(&st->lock);
/*
* Go over HT siblings and check whether one of them has set up the
* shared state pointer already.
*/
for_each_cpu(cpu, topology_sibling_cpumask(this_cpu)) {
if (cpu == this_cpu)
continue;
if (!per_cpu(ssb_state, cpu).shared_state)
continue;
/* Link it to the state of the sibling: */
st->shared_state = per_cpu(ssb_state, cpu).shared_state;
return;
}
/*
* First HT sibling to come up on the core. Link shared state of
* the first HT sibling to itself. The siblings on the same core
* which come up later will see the shared state pointer and link
* themself to the state of this CPU.
*/
st->shared_state = st;
}
/*
* Logic is: First HT sibling enables SSBD for both siblings in the core
* and last sibling to disable it, disables it for the whole core. This how
* MSR_SPEC_CTRL works in "hardware":
*
* CORE_SPEC_CTRL = THREAD0_SPEC_CTRL | THREAD1_SPEC_CTRL
*/
static __always_inline void amd_set_core_ssb_state(unsigned long tifn)
{
struct ssb_state *st = this_cpu_ptr(&ssb_state);
u64 msr = x86_amd_ls_cfg_base;
if (!static_cpu_has(X86_FEATURE_ZEN)) {
msr |= ssbd_tif_to_amd_ls_cfg(tifn);
wrmsrl(MSR_AMD64_LS_CFG, msr);
return;
}
if (tifn & _TIF_SSBD) {
/*
* Since this can race with prctl(), block reentry on the
* same CPU.
*/
if (__test_and_set_bit(LSTATE_SSB, &st->local_state))
return;
msr |= x86_amd_ls_cfg_ssbd_mask;
raw_spin_lock(&st->shared_state->lock);
/* First sibling enables SSBD: */
if (!st->shared_state->disable_state)
wrmsrl(MSR_AMD64_LS_CFG, msr);
st->shared_state->disable_state++;
raw_spin_unlock(&st->shared_state->lock);
} else {
if (!__test_and_clear_bit(LSTATE_SSB, &st->local_state))
return;
raw_spin_lock(&st->shared_state->lock);
st->shared_state->disable_state--;
if (!st->shared_state->disable_state)
wrmsrl(MSR_AMD64_LS_CFG, msr);
raw_spin_unlock(&st->shared_state->lock);
}
}
#else
static __always_inline void amd_set_core_ssb_state(unsigned long tifn)
{
u64 msr = x86_amd_ls_cfg_base | ssbd_tif_to_amd_ls_cfg(tifn);
wrmsrl(MSR_AMD64_LS_CFG, msr);
}
#endif
static __always_inline void amd_set_ssb_virt_state(unsigned long tifn)
{
/*
* SSBD has the same definition in SPEC_CTRL and VIRT_SPEC_CTRL,
* so ssbd_tif_to_spec_ctrl() just works.
*/
wrmsrl(MSR_AMD64_VIRT_SPEC_CTRL, ssbd_tif_to_spec_ctrl(tifn));
}
/*
* Update the MSRs managing speculation control, during context switch.
*
* tifp: Previous task's thread flags
* tifn: Next task's thread flags
*/
static __always_inline void __speculation_ctrl_update(unsigned long tifp,
unsigned long tifn)
{
unsigned long tif_diff = tifp ^ tifn;
u64 msr = x86_spec_ctrl_base;
bool updmsr = false;
lockdep_assert_irqs_disabled();
/*
* If TIF_SSBD is different, select the proper mitigation
* method. Note that if SSBD mitigation is disabled or permanentely
* enabled this branch can't be taken because nothing can set
* TIF_SSBD.
*/
if (tif_diff & _TIF_SSBD) {
if (static_cpu_has(X86_FEATURE_VIRT_SSBD)) {
amd_set_ssb_virt_state(tifn);
} else if (static_cpu_has(X86_FEATURE_LS_CFG_SSBD)) {
amd_set_core_ssb_state(tifn);
} else if (static_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD) ||
static_cpu_has(X86_FEATURE_AMD_SSBD)) {
msr |= ssbd_tif_to_spec_ctrl(tifn);
updmsr = true;
}
}
/*
* Only evaluate TIF_SPEC_IB if conditional STIBP is enabled,
* otherwise avoid the MSR write.
*/
if (IS_ENABLED(CONFIG_SMP) &&
static_branch_unlikely(&switch_to_cond_stibp)) {
updmsr |= !!(tif_diff & _TIF_SPEC_IB);
msr |= stibp_tif_to_spec_ctrl(tifn);
}
if (updmsr)
wrmsrl(MSR_IA32_SPEC_CTRL, msr);
}
static unsigned long speculation_ctrl_update_tif(struct task_struct *tsk)
{
if (test_and_clear_tsk_thread_flag(tsk, TIF_SPEC_FORCE_UPDATE)) {
if (task_spec_ssb_disable(tsk))
set_tsk_thread_flag(tsk, TIF_SSBD);
else
clear_tsk_thread_flag(tsk, TIF_SSBD);
if (task_spec_ib_disable(tsk))
set_tsk_thread_flag(tsk, TIF_SPEC_IB);
else
clear_tsk_thread_flag(tsk, TIF_SPEC_IB);
}
/* Return the updated threadinfo flags*/
return task_thread_info(tsk)->flags;
}
void speculation_ctrl_update(unsigned long tif)
{
unsigned long flags;
/* Forced update. Make sure all relevant TIF flags are different */
local_irq_save(flags);
__speculation_ctrl_update(~tif, tif);
local_irq_restore(flags);
}
/* Called from seccomp/prctl update */
void speculation_ctrl_update_current(void)
{
preempt_disable();
speculation_ctrl_update(speculation_ctrl_update_tif(current));
preempt_enable();
}
void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p)
{
struct thread_struct *prev, *next;
unsigned long tifp, tifn;
prev = &prev_p->thread;
next = &next_p->thread;
tifn = READ_ONCE(task_thread_info(next_p)->flags);
tifp = READ_ONCE(task_thread_info(prev_p)->flags);
switch_to_bitmap(prev, next, tifp, tifn);
propagate_user_return_notify(prev_p, next_p);
if ((tifp & _TIF_BLOCKSTEP || tifn & _TIF_BLOCKSTEP) &&
arch_has_block_step()) {
unsigned long debugctl, msk;
rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
debugctl &= ~DEBUGCTLMSR_BTF;
msk = tifn & _TIF_BLOCKSTEP;
debugctl |= (msk >> TIF_BLOCKSTEP) << DEBUGCTLMSR_BTF_SHIFT;
wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
}
if ((tifp ^ tifn) & _TIF_NOTSC)
cr4_toggle_bits_irqsoff(X86_CR4_TSD);
if ((tifp ^ tifn) & _TIF_NOCPUID)
set_cpuid_faulting(!!(tifn & _TIF_NOCPUID));
if (likely(!((tifp | tifn) & _TIF_SPEC_FORCE_UPDATE))) {
__speculation_ctrl_update(tifp, tifn);
} else {
speculation_ctrl_update_tif(prev_p);
tifn = speculation_ctrl_update_tif(next_p);
/* Enforce MSR update to ensure consistent state */
__speculation_ctrl_update(~tifn, tifn);
}
}
/*
* Idle related variables and functions
*/
unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
EXPORT_SYMBOL(boot_option_idle_override);
static void (*x86_idle)(void);
#ifndef CONFIG_SMP
static inline void play_dead(void)
{
BUG();
}
#endif
void arch_cpu_idle_enter(void)
{
tsc_verify_tsc_adjust(false);
local_touch_nmi();
}
void arch_cpu_idle_dead(void)
{
play_dead();
}
/*
* Called from the generic idle code.
*/
void arch_cpu_idle(void)
{
x86_idle();
}
/*
* We use this if we don't have any better idle routine..
*/
void __cpuidle default_idle(void)
{
trace_cpu_idle_rcuidle(1, smp_processor_id());
safe_halt();
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
}
#ifdef CONFIG_APM_MODULE
EXPORT_SYMBOL(default_idle);
#endif
#ifdef CONFIG_XEN
bool xen_set_default_idle(void)
{
bool ret = !!x86_idle;
x86_idle = default_idle;
return ret;
}
#endif
void stop_this_cpu(void *dummy)
{
local_irq_disable();
/*
* Remove this CPU:
*/
set_cpu_online(smp_processor_id(), false);
disable_local_APIC();
mcheck_cpu_clear(this_cpu_ptr(&cpu_info));
/*
* Use wbinvd on processors that support SME. This provides support
* for performing a successful kexec when going from SME inactive
* to SME active (or vice-versa). The cache must be cleared so that
* if there are entries with the same physical address, both with and
* without the encryption bit, they don't race each other when flushed
* and potentially end up with the wrong entry being committed to
* memory.
*/
if (boot_cpu_has(X86_FEATURE_SME))
native_wbinvd();
for (;;) {
/*
* Use native_halt() so that memory contents don't change
* (stack usage and variables) after possibly issuing the
* native_wbinvd() above.
*/
native_halt();
}
}
/*
* AMD Erratum 400 aware idle routine. We handle it the same way as C3 power
* states (local apic timer and TSC stop).
*/
static void amd_e400_idle(void)
{
/*
* We cannot use static_cpu_has_bug() here because X86_BUG_AMD_APIC_C1E
* gets set after static_cpu_has() places have been converted via
* alternatives.
*/
if (!boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E)) {
default_idle();
return;
}
tick_broadcast_enter();
default_idle();
/*
* The switch back from broadcast mode needs to be called with
* interrupts disabled.
*/
local_irq_disable();
tick_broadcast_exit();
local_irq_enable();
}
/*
* Intel Core2 and older machines prefer MWAIT over HALT for C1.
* We can't rely on cpuidle installing MWAIT, because it will not load
* on systems that support only C1 -- so the boot default must be MWAIT.
*
* Some AMD machines are the opposite, they depend on using HALT.
*
* So for default C1, which is used during boot until cpuidle loads,
* use MWAIT-C1 on Intel HW that has it, else use HALT.
*/
static int prefer_mwait_c1_over_halt(const struct cpuinfo_x86 *c)
{
if (c->x86_vendor != X86_VENDOR_INTEL)
return 0;
if (!cpu_has(c, X86_FEATURE_MWAIT) || boot_cpu_has_bug(X86_BUG_MONITOR))
return 0;
return 1;
}
/*
* MONITOR/MWAIT with no hints, used for default C1 state. This invokes MWAIT
* with interrupts enabled and no flags, which is backwards compatible with the
* original MWAIT implementation.
*/
static __cpuidle void mwait_idle(void)
{
if (!current_set_polling_and_test()) {
trace_cpu_idle_rcuidle(1, smp_processor_id());
if (this_cpu_has(X86_BUG_CLFLUSH_MONITOR)) {
mb(); /* quirk */
clflush((void *)¤t_thread_info()->flags);
mb(); /* quirk */
}
__monitor((void *)¤t_thread_info()->flags, 0, 0);
if (!need_resched())
__sti_mwait(0, 0);
else
local_irq_enable();
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
} else {
local_irq_enable();
}
__current_clr_polling();
}
void select_idle_routine(const struct cpuinfo_x86 *c)
{
#ifdef CONFIG_SMP
if (boot_option_idle_override == IDLE_POLL && smp_num_siblings > 1)
pr_warn_once("WARNING: polling idle and HT enabled, performance may degrade\n");
#endif
if (x86_idle || boot_option_idle_override == IDLE_POLL)
return;
if (boot_cpu_has_bug(X86_BUG_AMD_E400)) {
pr_info("using AMD E400 aware idle routine\n");
x86_idle = amd_e400_idle;
} else if (prefer_mwait_c1_over_halt(c)) {
pr_info("using mwait in idle threads\n");
x86_idle = mwait_idle;
} else
x86_idle = default_idle;
}
void amd_e400_c1e_apic_setup(void)
{
if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E)) {
pr_info("Switch to broadcast mode on CPU%d\n", smp_processor_id());
local_irq_disable();
tick_broadcast_force();
local_irq_enable();
}
}
void __init arch_post_acpi_subsys_init(void)
{
u32 lo, hi;
if (!boot_cpu_has_bug(X86_BUG_AMD_E400))
return;
/*
* AMD E400 detection needs to happen after ACPI has been enabled. If
* the machine is affected K8_INTP_C1E_ACTIVE_MASK bits are set in
* MSR_K8_INT_PENDING_MSG.
*/
rdmsr(MSR_K8_INT_PENDING_MSG, lo, hi);
if (!(lo & K8_INTP_C1E_ACTIVE_MASK))
return;
boot_cpu_set_bug(X86_BUG_AMD_APIC_C1E);
if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
mark_tsc_unstable("TSC halt in AMD C1E");
pr_info("System has AMD C1E enabled\n");
}
static int __init idle_setup(char *str)
{
if (!str)
return -EINVAL;
if (!strcmp(str, "poll")) {
pr_info("using polling idle threads\n");
boot_option_idle_override = IDLE_POLL;
cpu_idle_poll_ctrl(true);
} else if (!strcmp(str, "halt")) {
/*
* When the boot option of idle=halt is added, halt is
* forced to be used for CPU idle. In such case CPU C2/C3
* won't be used again.
* To continue to load the CPU idle driver, don't touch
* the boot_option_idle_override.
*/
x86_idle = default_idle;
boot_option_idle_override = IDLE_HALT;
} else if (!strcmp(str, "nomwait")) {
/*
* If the boot option of "idle=nomwait" is added,
* it means that mwait will be disabled for CPU C2/C3
* states. In such case it won't touch the variable
* of boot_option_idle_override.
*/
boot_option_idle_override = IDLE_NOMWAIT;
} else
return -1;
return 0;
}
early_param("idle", idle_setup);
unsigned long arch_align_stack(unsigned long sp)
{
if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
sp -= get_random_int() % 8192;
return sp & ~0xf;
}
unsigned long arch_randomize_brk(struct mm_struct *mm)
{
return randomize_page(mm->brk, 0x02000000);
}
/*
* Called from fs/proc with a reference on @p to find the function
* which called into schedule(). This needs to be done carefully
* because the task might wake up and we might look at a stack
* changing under us.
*/
unsigned long get_wchan(struct task_struct *p)
{
unsigned long start, bottom, top, sp, fp, ip, ret = 0;
int count = 0;
if (p == current || p->state == TASK_RUNNING)
return 0;
if (!try_get_task_stack(p))
return 0;
start = (unsigned long)task_stack_page(p);
if (!start)
goto out;
/*
* Layout of the stack page:
*
* ----------- topmax = start + THREAD_SIZE - sizeof(unsigned long)
* PADDING
* ----------- top = topmax - TOP_OF_KERNEL_STACK_PADDING
* stack
* ----------- bottom = start
*
* The tasks stack pointer points at the location where the
* framepointer is stored. The data on the stack is:
* ... IP FP ... IP FP
*
* We need to read FP and IP, so we need to adjust the upper
* bound by another unsigned long.
*/
top = start + THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING;
top -= 2 * sizeof(unsigned long);
bottom = start;
sp = READ_ONCE(p->thread.sp);
if (sp < bottom || sp > top)
goto out;
fp = READ_ONCE_NOCHECK(((struct inactive_task_frame *)sp)->bp);
do {
if (fp < bottom || fp > top)
goto out;
ip = READ_ONCE_NOCHECK(*(unsigned long *)(fp + sizeof(unsigned long)));
if (!in_sched_functions(ip)) {
ret = ip;
goto out;
}
fp = READ_ONCE_NOCHECK(*(unsigned long *)fp);
} while (count++ < 16 && p->state != TASK_RUNNING);
out:
put_task_stack(p);
return ret;
}
long do_arch_prctl_common(struct task_struct *task, int option,
unsigned long cpuid_enabled)
{
switch (option) {
case ARCH_GET_CPUID:
return get_cpuid_mode();
case ARCH_SET_CPUID:
return set_cpuid_mode(task, cpuid_enabled);
}
return -EINVAL;
}