Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 asm updates from Ingo Molnar:
 "Misc changes:

   - context switch micro-optimization
   - debug printout micro-optimization
   - comment enhancements and typo fix"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Replace seq_printf() with seq_puts()
  x86/asm: Fix typo in arch/x86/kernel/asm_offset_64.c
  sched/x86: Add a comment clarifying LDT context switching
  sched/x86_64: Don't save flags on context switch
This commit is contained in:
Linus Torvalds 2014-12-10 12:09:26 -08:00
commit 9d0cf6f564
7 changed files with 51 additions and 41 deletions

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@ -52,7 +52,16 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
/* Stop flush ipis for the previous mm */
cpumask_clear_cpu(cpu, mm_cpumask(prev));
/* Load the LDT, if the LDT is different: */
/*
* Load the LDT, if the LDT is different.
*
* It's possible leave_mm(prev) has been called. If so,
* then prev->context.ldt could be out of sync with the
* LDT descriptor or the LDT register. This can only happen
* if prev->context.ldt is non-null, since we never free
* an LDT. But LDTs can't be shared across mms, so
* prev->context.ldt won't be equal to next->context.ldt.
*/
if (unlikely(prev->context.ldt != next->context.ldt))
load_LDT_nolock(&next->context);
}

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@ -79,12 +79,12 @@ do { \
#else /* CONFIG_X86_32 */
/* frame pointer must be last for get_wchan */
#define SAVE_CONTEXT "pushf ; pushq %%rbp ; movq %%rsi,%%rbp\n\t"
#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp ; popf\t"
#define SAVE_CONTEXT "pushq %%rbp ; movq %%rsi,%%rbp\n\t"
#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp\t"
#define __EXTRA_CLOBBER \
, "rcx", "rbx", "rdx", "r8", "r9", "r10", "r11", \
"r12", "r13", "r14", "r15"
"r12", "r13", "r14", "r15", "flags"
#ifdef CONFIG_CC_STACKPROTECTOR
#define __switch_canary \
@ -100,7 +100,11 @@ do { \
#define __switch_canary_iparam
#endif /* CC_STACKPROTECTOR */
/* Save restore flags to clear handle leaking NT */
/*
* There is no need to save or restore flags, because flags are always
* clean in kernel mode, with the possible exception of IOPL. Kernel IOPL
* has no effect.
*/
#define switch_to(prev, next, last) \
asm volatile(SAVE_CONTEXT \
"movq %%rsp,%P[threadrsp](%[prev])\n\t" /* save RSP */ \

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@ -47,7 +47,6 @@ int main(void)
#endif
#define ENTRY(entry) OFFSET(pt_regs_ ## entry, pt_regs, entry)
ENTRY(bx);
ENTRY(bx);
ENTRY(cx);
ENTRY(dx);

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@ -72,7 +72,7 @@ static int show_cpuinfo(struct seq_file *m, void *v)
if (c->x86_mask || c->cpuid_level >= 0)
seq_printf(m, "stepping\t: %d\n", c->x86_mask);
else
seq_printf(m, "stepping\t: unknown\n");
seq_puts(m, "stepping\t: unknown\n");
if (c->microcode)
seq_printf(m, "microcode\t: 0x%x\n", c->microcode);
@ -92,12 +92,12 @@ static int show_cpuinfo(struct seq_file *m, void *v)
show_cpuinfo_core(m, c, cpu);
show_cpuinfo_misc(m, c);
seq_printf(m, "flags\t\t:");
seq_puts(m, "flags\t\t:");
for (i = 0; i < 32*NCAPINTS; i++)
if (cpu_has(c, i) && x86_cap_flags[i] != NULL)
seq_printf(m, " %s", x86_cap_flags[i]);
seq_printf(m, "\nbugs\t\t:");
seq_puts(m, "\nbugs\t\t:");
for (i = 0; i < 32*NBUGINTS; i++) {
unsigned int bug_bit = 32*NCAPINTS + i;
@ -118,7 +118,7 @@ static int show_cpuinfo(struct seq_file *m, void *v)
seq_printf(m, "address sizes\t: %u bits physical, %u bits virtual\n",
c->x86_phys_bits, c->x86_virt_bits);
seq_printf(m, "power management:");
seq_puts(m, "power management:");
for (i = 0; i < 32; i++) {
if (c->x86_power & (1 << i)) {
if (i < ARRAY_SIZE(x86_power_flags) &&
@ -131,7 +131,7 @@ static int show_cpuinfo(struct seq_file *m, void *v)
}
}
seq_printf(m, "\n\n");
seq_puts(m, "\n\n");
return 0;
}

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@ -59,78 +59,78 @@ int arch_show_interrupts(struct seq_file *p, int prec)
seq_printf(p, "%*s: ", prec, "NMI");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->__nmi_count);
seq_printf(p, " Non-maskable interrupts\n");
seq_puts(p, " Non-maskable interrupts\n");
#ifdef CONFIG_X86_LOCAL_APIC
seq_printf(p, "%*s: ", prec, "LOC");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->apic_timer_irqs);
seq_printf(p, " Local timer interrupts\n");
seq_puts(p, " Local timer interrupts\n");
seq_printf(p, "%*s: ", prec, "SPU");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_spurious_count);
seq_printf(p, " Spurious interrupts\n");
seq_puts(p, " Spurious interrupts\n");
seq_printf(p, "%*s: ", prec, "PMI");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->apic_perf_irqs);
seq_printf(p, " Performance monitoring interrupts\n");
seq_puts(p, " Performance monitoring interrupts\n");
seq_printf(p, "%*s: ", prec, "IWI");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->apic_irq_work_irqs);
seq_printf(p, " IRQ work interrupts\n");
seq_puts(p, " IRQ work interrupts\n");
seq_printf(p, "%*s: ", prec, "RTR");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->icr_read_retry_count);
seq_printf(p, " APIC ICR read retries\n");
seq_puts(p, " APIC ICR read retries\n");
#endif
if (x86_platform_ipi_callback) {
seq_printf(p, "%*s: ", prec, "PLT");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->x86_platform_ipis);
seq_printf(p, " Platform interrupts\n");
seq_puts(p, " Platform interrupts\n");
}
#ifdef CONFIG_SMP
seq_printf(p, "%*s: ", prec, "RES");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
seq_printf(p, " Rescheduling interrupts\n");
seq_puts(p, " Rescheduling interrupts\n");
seq_printf(p, "%*s: ", prec, "CAL");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_call_count -
irq_stats(j)->irq_tlb_count);
seq_printf(p, " Function call interrupts\n");
seq_puts(p, " Function call interrupts\n");
seq_printf(p, "%*s: ", prec, "TLB");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
seq_printf(p, " TLB shootdowns\n");
seq_puts(p, " TLB shootdowns\n");
#endif
#ifdef CONFIG_X86_THERMAL_VECTOR
seq_printf(p, "%*s: ", prec, "TRM");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_thermal_count);
seq_printf(p, " Thermal event interrupts\n");
seq_puts(p, " Thermal event interrupts\n");
#endif
#ifdef CONFIG_X86_MCE_THRESHOLD
seq_printf(p, "%*s: ", prec, "THR");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_threshold_count);
seq_printf(p, " Threshold APIC interrupts\n");
seq_puts(p, " Threshold APIC interrupts\n");
#endif
#ifdef CONFIG_X86_MCE
seq_printf(p, "%*s: ", prec, "MCE");
for_each_online_cpu(j)
seq_printf(p, "%10u ", per_cpu(mce_exception_count, j));
seq_printf(p, " Machine check exceptions\n");
seq_puts(p, " Machine check exceptions\n");
seq_printf(p, "%*s: ", prec, "MCP");
for_each_online_cpu(j)
seq_printf(p, "%10u ", per_cpu(mce_poll_count, j));
seq_printf(p, " Machine check polls\n");
seq_puts(p, " Machine check polls\n");
#endif
#if IS_ENABLED(CONFIG_HYPERV) || defined(CONFIG_XEN)
seq_printf(p, "%*s: ", prec, "THR");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_hv_callback_count);
seq_printf(p, " Hypervisor callback interrupts\n");
seq_puts(p, " Hypervisor callback interrupts\n");
#endif
seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
#if defined(CONFIG_X86_IO_APIC)

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@ -824,7 +824,7 @@ static void *memtype_seq_start(struct seq_file *seq, loff_t *pos)
{
if (*pos == 0) {
++*pos;
seq_printf(seq, "PAT memtype list:\n");
seq_puts(seq, "PAT memtype list:\n");
}
return memtype_get_idx(*pos);

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@ -1367,20 +1367,18 @@ static int ptc_seq_show(struct seq_file *file, void *data)
cpu = *(loff_t *)data;
if (!cpu) {
seq_printf(file,
"# cpu bauoff sent stime self locals remotes ncpus localhub ");
seq_printf(file,
"remotehub numuvhubs numuvhubs16 numuvhubs8 ");
seq_printf(file,
"numuvhubs4 numuvhubs2 numuvhubs1 dto snacks retries ");
seq_printf(file,
"rok resetp resett giveup sto bz throt disable ");
seq_printf(file,
"enable wars warshw warwaits enters ipidis plugged ");
seq_printf(file,
"ipiover glim cong swack recv rtime all one mult ");
seq_printf(file,
"none retry canc nocan reset rcan\n");
seq_puts(file,
"# cpu bauoff sent stime self locals remotes ncpus localhub ");
seq_puts(file, "remotehub numuvhubs numuvhubs16 numuvhubs8 ");
seq_puts(file,
"numuvhubs4 numuvhubs2 numuvhubs1 dto snacks retries ");
seq_puts(file,
"rok resetp resett giveup sto bz throt disable ");
seq_puts(file,
"enable wars warshw warwaits enters ipidis plugged ");
seq_puts(file,
"ipiover glim cong swack recv rtime all one mult ");
seq_puts(file, "none retry canc nocan reset rcan\n");
}
if (cpu < num_possible_cpus() && cpu_online(cpu)) {
bcp = &per_cpu(bau_control, cpu);