/*
* AMD Erratum 400 aware idle routine. We check for C1E active in the interrupt
* pending message MSR. If we detect C1E, then we handle it the same
* way as C3 power states (local apic timer and TSC stop)
*/
static void amd_e400_idle(void)
{
if (!amd_e400_c1e_detected) {
u32 lo, hi;
rdmsr(MSR_K8_INT_PENDING_MSG, lo, hi);
if (lo & K8_INTP_C1E_ACTIVE_MASK) {
amd_e400_c1e_detected = true;
if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
mark_tsc_unstable("TSC halt in AMD C1E");
pr_info("System has AMD C1E enabled\n");
}
}
if (amd_e400_c1e_detected) {
int cpu = smp_processor_id();
if (!cpumask_test_cpu(cpu, amd_e400_c1e_mask)) {
cpumask_set_cpu(cpu, amd_e400_c1e_mask);
/* Force broadcast so ACPI can not interfere. */
tick_broadcast_force();
pr_info("Switch to broadcast mode on CPU%d\n", cpu);
}
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();
} else
default_idle();
}
/*H:126 i386-specific hypercall initialization: */
int lguest_arch_init_hypercalls(struct lg_cpu *cpu)
{
u32 tsc_speed;
/*
* The pointer to the Guest's "struct lguest_data" is the only argument.
* We check that address now.
*/
if (!lguest_address_ok(cpu->lg, cpu->hcall->arg1,
sizeof(*cpu->lg->lguest_data)))
return -EFAULT;
/*
* Having checked it, we simply set lg->lguest_data to point straight
* into the Launcher's memory at the right place and then use
* copy_to_user/from_user from now on, instead of lgread/write. I put
* this in to show that I'm not immune to writing stupid
* optimizations.
*/
cpu->lg->lguest_data = cpu->lg->mem_base + cpu->hcall->arg1;
/*
* We insist that the Time Stamp Counter exist and doesn't change with
* cpu frequency. Some devious chip manufacturers decided that TSC
* changes could be handled in software. I decided that time going
* backwards might be good for benchmarks, but it's bad for users.
*
* We also insist that the TSC be stable: the kernel detects unreliable
* TSCs for its own purposes, and we use that here.
*/
if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC) && !check_tsc_unstable())
tsc_speed = tsc_khz;
else
tsc_speed = 0;
if (put_user(tsc_speed, &cpu->lg->lguest_data->tsc_khz))
return -EFAULT;
/* The interrupt code might not like the system call vector. */
if (!check_syscall_vector(cpu->lg))
kill_guest(cpu, "bad syscall vector");
return 0;
}
static void tsc_check_state(int state)
{
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_AMD:
case X86_VENDOR_INTEL:
/*
* AMD Fam10h TSC will tick in all
* C/P/S0/S1 states when this bit is set.
*/
if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
return;
/*FALL THROUGH*/
default:
/* TSC could halt in idle, so notify users */
if (state > ACPI_STATE_C1)
mark_tsc_unstable("TSC halts in idle");
}
}
/* Look at the bits in MSR_IA32_APICBASE and work out which
* APIC mode we are in */
enum apic_mode current_local_apic_mode(void)
{
u64 msr_contents;
rdmsrl(MSR_IA32_APICBASE, msr_contents);
/* Reading EXTD bit from the MSR is only valid if CPUID
* says so, else reserved */
if ( boot_cpu_has(X86_FEATURE_X2APIC)
&& (msr_contents & MSR_IA32_APICBASE_EXTD) )
return APIC_MODE_X2APIC;
/* EN bit should always be valid as long as we can read the MSR
*/
if ( msr_contents & MSR_IA32_APICBASE_ENABLE )
return APIC_MODE_XAPIC;
return APIC_MODE_DISABLED;
}
static
#endif
int acpi_processor_get_performance_info(struct acpi_processor *pr)
{
int result = 0;
acpi_status status = AE_OK;
acpi_handle handle = NULL;
if (!pr || !pr->performance || !pr->handle)
return -EINVAL;
status = acpi_get_handle(pr->handle, "_PCT", &handle);
if (ACPI_FAILURE(status)) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"ACPI-based processor performance control unavailable\n"));
return -ENODEV;
}
result = acpi_processor_get_performance_control(pr);
if (result)
goto update_bios;
result = acpi_processor_get_performance_states(pr);
if (result)
goto update_bios;
return 0;
/*
* Having _PPC but missing frequencies (_PSS, _PCT) is a very good hint that
* the BIOS is older than the CPU and does not know its frequencies
*/
update_bios:
#ifdef CONFIG_X86
if (ACPI_SUCCESS(acpi_get_handle(pr->handle, "_PPC", &handle))){
if(boot_cpu_has(X86_FEATURE_EST))
printk(KERN_WARNING FW_BUG "BIOS needs update for CPU "
"frequency support\n");
}
#endif
return result;
}
static __init u32 __get_ibs_caps(void)
{
u32 caps;
unsigned int max_level;
if (!boot_cpu_has(X86_FEATURE_IBS))
return 0;
/* check IBS cpuid feature flags */
max_level = cpuid_eax(0x80000000);
if (max_level < IBS_CPUID_FEATURES)
return IBS_CAPS_DEFAULT;
caps = cpuid_eax(IBS_CPUID_FEATURES);
if (!(caps & IBS_CAPS_AVAIL))
/* cpuid flags not valid */
return IBS_CAPS_DEFAULT;
return caps;
}
void __cpuinit xen_enable_syscall(void)
{
#ifdef CONFIG_X86_64
int ret;
ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
if (ret != 0) {
printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
/*
*/
}
if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
ret = register_callback(CALLBACKTYPE_syscall32,
xen_syscall32_target);
if (ret != 0)
setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
}
#endif /* */
}
static __init int intel_epb_init(void)
{
int ret;
if (!boot_cpu_has(X86_FEATURE_EPB))
return -ENODEV;
ret = cpuhp_setup_state(CPUHP_AP_X86_INTEL_EPB_ONLINE,
"x86/intel/epb:online", intel_epb_online,
intel_epb_offline);
if (ret < 0)
goto err_out_online;
register_syscore_ops(&intel_epb_syscore_ops);
return 0;
err_out_online:
cpuhp_remove_state(CPUHP_AP_X86_INTEL_EPB_ONLINE);
return ret;
}
static int cmci_supported(int *banks)
{
u64 cap;
if (mca_cfg.cmci_disabled || mca_cfg.ignore_ce)
return 0;
/*
* Vendor check is not strictly needed, but the initial
* initialization is vendor keyed and this
* makes sure none of the backdoors are entered otherwise.
*/
if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
return 0;
if (!boot_cpu_has(X86_FEATURE_APIC) || lapic_get_maxlvt() < 6)
return 0;
rdmsrl(MSR_IA32_MCG_CAP, cap);
*banks = min_t(unsigned, MAX_NR_BANKS, cap & 0xff);
return !!(cap & MCG_CMCI_P);
}
static int __init sysenter_setup(void)
{
unsigned long page = get_zeroed_page(GFP_ATOMIC);
__set_fixmap(FIX_VSYSCALL, __pa(page), PAGE_READONLY_EXEC);
if (!boot_cpu_has(X86_FEATURE_SEP)) {
memcpy((void *) page,
&vsyscall_int80_start,
&vsyscall_int80_end - &vsyscall_int80_start);
return 0;
}
memcpy((void *) page,
&vsyscall_sysenter_start,
&vsyscall_sysenter_end - &vsyscall_sysenter_start);
on_each_cpu(enable_sep_cpu, NULL, 1, 1);
return 0;
}
void __init setup_boot_APIC_clock(void)
{
unsigned long flags;
apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n");
using_apic_timer = 1;
local_irq_save(flags);
calibrate_APIC_clock();
if ( tdt_enable && boot_cpu_has(X86_FEATURE_TSC_DEADLINE) )
{
printk(KERN_DEBUG "TSC deadline timer enabled\n");
tdt_enabled = 1;
}
setup_APIC_timer();
local_irq_restore(flags);
}
void __cpuinit xen_enable_syscall(void)
{
#ifdef CONFIG_X86_64
int ret;
ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
if (ret != 0) {
printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
/* Pretty fatal; 64-bit userspace has no other
mechanism for syscalls. */
}
if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
ret = register_callback(CALLBACKTYPE_syscall32,
xen_syscall32_target);
if (ret != 0)
setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
}
#endif /* CONFIG_X86_64 */
}
static int __init padlock_init(void)
{
int ret;
struct cpuinfo_x86 *c = &cpu_data(0);
if (!x86_match_cpu(padlock_cpu_id))
return -ENODEV;
if (!boot_cpu_has(X86_FEATURE_XCRYPT_EN)) {
printk(KERN_NOTICE PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
return -ENODEV;
}
if ((ret = crypto_register_alg(&aes_alg)))
goto aes_err;
if ((ret = crypto_register_alg(&ecb_aes_alg)))
goto ecb_aes_err;
if ((ret = crypto_register_alg(&cbc_aes_alg)))
goto cbc_aes_err;
printk(KERN_NOTICE PFX "Using VIA PadLock ACE for AES algorithm.\n");
if (c->x86 == 6 && c->x86_model == 15 && c->x86_stepping == 2) {
ecb_fetch_blocks = MAX_ECB_FETCH_BLOCKS;
cbc_fetch_blocks = MAX_CBC_FETCH_BLOCKS;
printk(KERN_NOTICE PFX "VIA Nano stepping 2 detected: enabling workaround.\n");
}
out:
return ret;
cbc_aes_err:
crypto_unregister_alg(&ecb_aes_alg);
ecb_aes_err:
crypto_unregister_alg(&aes_alg);
aes_err:
printk(KERN_ERR PFX "VIA PadLock AES initialization failed.\n");
goto out;
}
/*
* This function sets up the local APIC timer, with a timeout of
* 'clocks' APIC bus clock. During calibration we actually call
* this function twice on the boot CPU, once with a bogus timeout
* value, second time for real. The other (noncalibrating) CPUs
* call this function only once, with the real, calibrated value.
*
* We do reads before writes even if unnecessary, to get around the
* P5 APIC double write bug.
*/
static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
{
unsigned int lvtt_value, tmp_value;
lvtt_value = LOCAL_TIMER_VECTOR;
if (!oneshot)
lvtt_value |= APIC_LVT_TIMER_PERIODIC;
else if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
lvtt_value |= APIC_LVT_TIMER_TSCDEADLINE;
if (!lapic_is_integrated())
lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
if (!irqen)
lvtt_value |= APIC_LVT_MASKED;
apic_write(APIC_LVTT, lvtt_value);
if (lvtt_value & APIC_LVT_TIMER_TSCDEADLINE) {
/*
* See Intel SDM: TSC-Deadline Mode chapter. In xAPIC mode,
* writing to the APIC LVTT and TSC_DEADLINE MSR isn't serialized.
* According to Intel, MFENCE can do the serialization here.
*/
asm volatile("mfence" : : : "memory");
printk_once(KERN_DEBUG "TSC deadline timer enabled\n");
return;
}
/*
* Divide PICLK by 16
*/
tmp_value = apic_read(APIC_TDCR);
apic_write(APIC_TDCR,
(tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
APIC_TDR_DIV_16);
if (!oneshot)
apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
}
void __init x86_report_nx(void)
{
if (!boot_cpu_has(X86_FEATURE_NX)) {
printk(KERN_NOTICE "Notice: NX (Execute Disable) protection "
"missing in CPU!\n");
} else {
#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
if (disable_nx) {
printk(KERN_INFO "NX (Execute Disable) protection: "
"disabled by kernel command line option\n");
} else {
printk(KERN_INFO "NX (Execute Disable) protection: "
"active\n");
}
#else
/* 32bit non-PAE kernel, NX cannot be used */
printk(KERN_NOTICE "Notice: NX (Execute Disable) protection "
"cannot be enabled: non-PAE kernel!\n");
#endif
}
}
/* Replace instructions with better alternatives for this CPU type.
This runs before SMP is initialized to avoid SMP problems with
self modifying code. This implies that assymetric systems where
APs have less capabilities than the boot processor are not handled.
In this case boot with "noreplacement". */
void apply_alternatives(void *start, void *end)
{
struct alt_instr *a;
int diff, i, k;
for (a = start; (void *)a < end; a++) {
if (!boot_cpu_has(a->cpuid))
continue;
BUG_ON(a->replacementlen > a->instrlen);
__inline_memcpy(a->instr, a->replacement, a->replacementlen);
diff = a->instrlen - a->replacementlen;
/* Pad the rest with nops */
for (i = a->replacementlen; diff > 0; diff -= k, i += k) {
k = diff;
if (k > ASM_NOP_MAX)
k = ASM_NOP_MAX;
__inline_memcpy(a->instr + i, k8_nops[k], k);
}
}
}
/*
* Replace instructions with better alternatives for this CPU type.
* This runs before SMP is initialized to avoid SMP problems with
* self modifying code. This implies that asymmetric systems where
* APs have less capabilities than the boot processor are not handled.
* Tough. Make sure you disable such features by hand.
*/
static void __init apply_alternatives(struct alt_instr *start, struct alt_instr *end)
{
struct alt_instr *a;
u8 *instr, *replacement;
u8 insnbuf[MAX_PATCH_LEN];
ASSERT(!local_irq_is_enabled());
printk(KERN_INFO "alt table %p -> %p\n", start, end);
/*
* The scan order should be from start to end. A later scanned
* alternative code can overwrite a previous scanned alternative code.
* Some kernel functions (e.g. memcpy, memset, etc) use this order to
* patch code.
*
* So be careful if you want to change the scan order to any other
* order.
*/
for ( a = start; a < end; a++ )
{
instr = (u8 *)&a->instr_offset + a->instr_offset;
replacement = (u8 *)&a->repl_offset + a->repl_offset;
BUG_ON(a->replacementlen > a->instrlen);
BUG_ON(a->instrlen > sizeof(insnbuf));
BUG_ON(a->cpuid >= NCAPINTS * 32);
if ( !boot_cpu_has(a->cpuid) )
continue;
memcpy(insnbuf, replacement, a->replacementlen);
/* 0xe8/0xe9 are relative branches; fix the offset. */
if ( (*insnbuf & 0xfe) == 0xe8 && a->replacementlen == 5 )
*(s32 *)(insnbuf + 1) += replacement - instr;
add_nops(insnbuf + a->replacementlen,
a->instrlen - a->replacementlen);
text_poke_early(instr, insnbuf, a->instrlen);
}
}
/*
* Some BIOS implementations switch to C3 in the published C2 state.
* This seems to be a common problem on AMD boxen, but other vendors
* are affected too. We pick the most conservative approach: we assume
* that the local APIC stops in both C2 and C3.
*/
static void lapic_timer_check_state(int state, struct acpi_processor *pr,
struct acpi_processor_cx *cx)
{
struct acpi_processor_power *pwr = &pr->power;
u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
return;
if (boot_cpu_has(X86_FEATURE_AMDC1E))
type = ACPI_STATE_C1;
/*
* Check, if one of the previous states already marked the lapic
* unstable
*/
if (pwr->timer_broadcast_on_state < state)
return;
if (cx->type >= type)
pr->power.timer_broadcast_on_state = state;
}
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");
}
bool_t lapic_timer_init(void)
{
if ( boot_cpu_has(X86_FEATURE_ARAT) )
{
lapic_timer_off = lapic_timer_nop;
lapic_timer_on = lapic_timer_nop;
}
else if ( hpet_broadcast_is_available() )
{
lapic_timer_off = hpet_broadcast_enter;
lapic_timer_on = hpet_broadcast_exit;
}
else if ( pit_broadcast_is_available() )
{
lapic_timer_off = pit_broadcast_enter;
lapic_timer_on = pit_broadcast_exit;
}
else
return 0;
return 1;
}
int lguest_arch_init_hypercalls(struct lg_cpu *cpu)
{
u32 tsc_speed;
if (!lguest_address_ok(cpu->lg, cpu->hcall->arg1,
sizeof(*cpu->lg->lguest_data)))
return -EFAULT;
cpu->lg->lguest_data = cpu->lg->mem_base + cpu->hcall->arg1;
if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC) && !check_tsc_unstable())
tsc_speed = tsc_khz;
else
tsc_speed = 0;
if (put_user(tsc_speed, &cpu->lg->lguest_data->tsc_khz))
return -EFAULT;
if (!check_syscall_vector(cpu->lg))
kill_guest(cpu, "bad syscall vector");
return 0;
}
static void __init intel_mid_time_init(void)
{
sfi_table_parse(SFI_SIG_MTMR, NULL, NULL, sfi_parse_mtmr);
switch (intel_mid_timer_options) {
case INTEL_MID_TIMER_APBT_ONLY:
break;
case INTEL_MID_TIMER_LAPIC_APBT:
/* Use apbt and local apic */
x86_init.timers.setup_percpu_clockev = intel_mid_setup_bp_timer;
x86_cpuinit.setup_percpu_clockev = setup_secondary_APIC_clock;
return;
default:
if (!boot_cpu_has(X86_FEATURE_ARAT))
break;
/* Lapic only, no apbt */
x86_init.timers.setup_percpu_clockev = setup_boot_APIC_clock;
x86_cpuinit.setup_percpu_clockev = setup_secondary_APIC_clock;
return;
}
x86_init.timers.setup_percpu_clockev = apbt_time_init;
}
void __restore_processor_state(struct saved_context *ctxt)
{
/*
* control registers
*/
write_cr4(ctxt->cr4);
write_cr3(ctxt->cr3);
write_cr2(ctxt->cr2);
write_cr2(ctxt->cr0);
/*
* now restore the descriptor tables to their proper values
* ltr is done i fix_processor_context().
*/
load_gdt(&ctxt->gdt_limit);
load_idt(&ctxt->idt_limit);
/*
* segment registers
*/
loadsegment(es, ctxt->es);
loadsegment(fs, ctxt->fs);
loadsegment(gs, ctxt->gs);
loadsegment(ss, ctxt->ss);
#ifdef CONFIG_SYSENTER
/*
* sysenter MSRs
*/
if (boot_cpu_has(X86_FEATURE_SEP))
enable_sep_cpu();
#endif
fix_processor_context();
do_fpu_end();
mtrr_ap_init();
}
static void __init intel_mid_time_init(void)
{
#ifdef CONFIG_SFI
sfi_table_parse(SFI_SIG_MTMR, NULL, NULL, sfi_parse_mtmr);
#endif
switch (intel_mid_timer_options) {
case INTEL_MID_TIMER_APBT_ONLY:
break;
case INTEL_MID_TIMER_LAPIC_APBT:
x86_init.timers.setup_percpu_clockev = setup_boot_APIC_clock;
x86_cpuinit.setup_percpu_clockev = setup_secondary_APIC_clock;
break;
default:
if (!boot_cpu_has(X86_FEATURE_ARAT))
break;
x86_init.timers.setup_percpu_clockev = setup_boot_APIC_clock;
x86_cpuinit.setup_percpu_clockev = setup_secondary_APIC_clock;
return;
}
/* we need at least one APB timer */
pre_init_apic_IRQ0();
apbt_time_init();
}
static bool test_irperf(int idx)
{
return boot_cpu_has(X86_FEATURE_IRPERF);
}
/*H:020
* Now the Switcher is mapped and every thing else is ready, we need to do
* some more i386-specific initialization.
*/
void __init lguest_arch_host_init(void)
{
int i;
/*
* Most of the x86/switcher_32.S doesn't care that it's been moved; on
* Intel, jumps are relative, and it doesn't access any references to
* external code or data.
*
* The only exception is the interrupt handlers in switcher.S: their
* addresses are placed in a table (default_idt_entries), so we need to
* update the table with the new addresses. switcher_offset() is a
* convenience function which returns the distance between the
* compiled-in switcher code and the high-mapped copy we just made.
*/
for (i = 0; i < IDT_ENTRIES; i++)
default_idt_entries[i] += switcher_offset();
/*
* Set up the Switcher's per-cpu areas.
*
* Each CPU gets two pages of its own within the high-mapped region
* (aka. "struct lguest_pages"). Much of this can be initialized now,
* but some depends on what Guest we are running (which is set up in
* copy_in_guest_info()).
*/
for_each_possible_cpu(i) {
/* lguest_pages() returns this CPU's two pages. */
struct lguest_pages *pages = lguest_pages(i);
/* This is a convenience pointer to make the code neater. */
struct lguest_ro_state *state = &pages->state;
/*
* The Global Descriptor Table: the Host has a different one
* for each CPU. We keep a descriptor for the GDT which says
* where it is and how big it is (the size is actually the last
* byte, not the size, hence the "-1").
*/
state->host_gdt_desc.size = GDT_SIZE-1;
state->host_gdt_desc.address = (long)get_cpu_gdt_table(i);
/*
* All CPUs on the Host use the same Interrupt Descriptor
* Table, so we just use store_idt(), which gets this CPU's IDT
* descriptor.
*/
store_idt(&state->host_idt_desc);
/*
* The descriptors for the Guest's GDT and IDT can be filled
* out now, too. We copy the GDT & IDT into ->guest_gdt and
* ->guest_idt before actually running the Guest.
*/
state->guest_idt_desc.size = sizeof(state->guest_idt)-1;
state->guest_idt_desc.address = (long)&state->guest_idt;
state->guest_gdt_desc.size = sizeof(state->guest_gdt)-1;
state->guest_gdt_desc.address = (long)&state->guest_gdt;
/*
* We know where we want the stack to be when the Guest enters
* the Switcher: in pages->regs. The stack grows upwards, so
* we start it at the end of that structure.
*/
state->guest_tss.sp0 = (long)(&pages->regs + 1);
/*
* And this is the GDT entry to use for the stack: we keep a
* couple of special LGUEST entries.
*/
state->guest_tss.ss0 = LGUEST_DS;
/*
* x86 can have a finegrained bitmap which indicates what I/O
* ports the process can use. We set it to the end of our
* structure, meaning "none".
*/
state->guest_tss.io_bitmap_base = sizeof(state->guest_tss);
/*
* Some GDT entries are the same across all Guests, so we can
* set them up now.
*/
setup_default_gdt_entries(state);
/* Most IDT entries are the same for all Guests, too.*/
setup_default_idt_entries(state, default_idt_entries);
/*
* The Host needs to be able to use the LGUEST segments on this
* CPU, too, so put them in the Host GDT.
*/
get_cpu_gdt_table(i)[GDT_ENTRY_LGUEST_CS] = FULL_EXEC_SEGMENT;
get_cpu_gdt_table(i)[GDT_ENTRY_LGUEST_DS] = FULL_SEGMENT;
}
/*
* In the Switcher, we want the %cs segment register to use the
* LGUEST_CS GDT entry: we've put that in the Host and Guest GDTs, so
* it will be undisturbed when we switch. To change %cs and jump we
* need this structure to feed to Intel's "lcall" instruction.
*/
lguest_entry.offset = (long)switch_to_guest + switcher_offset();
lguest_entry.segment = LGUEST_CS;
/*
* Finally, we need to turn off "Page Global Enable". PGE is an
* optimization where page table entries are specially marked to show
* they never change. The Host kernel marks all the kernel pages this
* way because it's always present, even when userspace is running.
*
* Lguest breaks this: unbeknownst to the rest of the Host kernel, we
* switch to the Guest kernel. If you don't disable this on all CPUs,
* you'll get really weird bugs that you'll chase for two days.
*
* I used to turn PGE off every time we switched to the Guest and back
* on when we return, but that slowed the Switcher down noticibly.
*/
/*
* We don't need the complexity of CPUs coming and going while we're
* doing this.
*/
get_online_cpus();
if (boot_cpu_has(X86_FEATURE_PGE)) { /* We have a broader idea of "global". */
/* Remember that this was originally set (for cleanup). */
cpu_had_pge = 1;
/*
* adjust_pge is a helper function which sets or unsets the PGE
* bit on its CPU, depending on the argument (0 == unset).
*/
on_each_cpu(adjust_pge, (void *)0, 1);
/* Turn off the feature in the global feature set. */
clear_cpu_cap(&boot_cpu_data, X86_FEATURE_PGE);
}
put_online_cpus();
}
void __init check_bugs(void)
{
identify_boot_cpu();
/*
* identify_boot_cpu() initialized SMT support information, let the
* core code know.
*/
cpu_smt_check_topology();
if (!IS_ENABLED(CONFIG_SMP)) {
pr_info("CPU: ");
print_cpu_info(&boot_cpu_data);
}
/*
* Read the SPEC_CTRL MSR to account for reserved bits which may
* have unknown values. AMD64_LS_CFG MSR is cached in the early AMD
* init code as it is not enumerated and depends on the family.
*/
if (boot_cpu_has(X86_FEATURE_MSR_SPEC_CTRL))
rdmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
/* Allow STIBP in MSR_SPEC_CTRL if supported */
if (boot_cpu_has(X86_FEATURE_STIBP))
x86_spec_ctrl_mask |= SPEC_CTRL_STIBP;
/* Select the proper spectre mitigation before patching alternatives */
spectre_v2_select_mitigation();
/*
* Select proper mitigation for any exposure to the Speculative Store
* Bypass vulnerability.
*/
ssb_select_mitigation();
l1tf_select_mitigation();
#ifdef CONFIG_X86_32
/*
* Check whether we are able to run this kernel safely on SMP.
*
* - i386 is no longer supported.
* - In order to run on anything without a TSC, we need to be
* compiled for a i486.
*/
if (boot_cpu_data.x86 < 4)
panic("Kernel requires i486+ for 'invlpg' and other features");
init_utsname()->machine[1] =
'0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86);
alternative_instructions();
fpu__init_check_bugs();
#else /* CONFIG_X86_64 */
alternative_instructions();
/*
* Make sure the first 2MB area is not mapped by huge pages
* There are typically fixed size MTRRs in there and overlapping
* MTRRs into large pages causes slow downs.
*
* Right now we don't do that with gbpages because there seems
* very little benefit for that case.
*/
if (!direct_gbpages)
set_memory_4k((unsigned long)__va(0), 1);
#endif
}
static __init int test_atomic64(void)
{
long long v0 = 0xaaa31337c001d00dLL;
long long v1 = 0xdeadbeefdeafcafeLL;
long long v2 = 0xfaceabadf00df001LL;
long long onestwos = 0x1111111122222222LL;
long long one = 1LL;
atomic64_t v = ATOMIC64_INIT(v0);
long long r = v0;
BUG_ON(v.counter != r);
atomic64_set(&v, v1);
r = v1;
BUG_ON(v.counter != r);
BUG_ON(atomic64_read(&v) != r);
INIT(v0);
atomic64_add(onestwos, &v);
r += onestwos;
BUG_ON(v.counter != r);
INIT(v0);
atomic64_add(-one, &v);
r += -one;
BUG_ON(v.counter != r);
INIT(v0);
r += onestwos;
BUG_ON(atomic64_add_return(onestwos, &v) != r);
BUG_ON(v.counter != r);
INIT(v0);
r += -one;
BUG_ON(atomic64_add_return(-one, &v) != r);
BUG_ON(v.counter != r);
INIT(v0);
atomic64_sub(onestwos, &v);
r -= onestwos;
BUG_ON(v.counter != r);
INIT(v0);
atomic64_sub(-one, &v);
r -= -one;
BUG_ON(v.counter != r);
INIT(v0);
r -= onestwos;
BUG_ON(atomic64_sub_return(onestwos, &v) != r);
BUG_ON(v.counter != r);
INIT(v0);
r -= -one;
BUG_ON(atomic64_sub_return(-one, &v) != r);
BUG_ON(v.counter != r);
INIT(v0);
atomic64_inc(&v);
r += one;
BUG_ON(v.counter != r);
INIT(v0);
r += one;
BUG_ON(atomic64_inc_return(&v) != r);
BUG_ON(v.counter != r);
INIT(v0);
atomic64_dec(&v);
r -= one;
BUG_ON(v.counter != r);
INIT(v0);
r -= one;
BUG_ON(atomic64_dec_return(&v) != r);
BUG_ON(v.counter != r);
INIT(v0);
BUG_ON(atomic64_xchg(&v, v1) != v0);
r = v1;
BUG_ON(v.counter != r);
INIT(v0);
BUG_ON(atomic64_cmpxchg(&v, v0, v1) != v0);
r = v1;
BUG_ON(v.counter != r);
INIT(v0);
BUG_ON(atomic64_cmpxchg(&v, v2, v1) != v0);
BUG_ON(v.counter != r);
INIT(v0);
BUG_ON(atomic64_add_unless(&v, one, v0));
BUG_ON(v.counter != r);
INIT(v0);
BUG_ON(!atomic64_add_unless(&v, one, v1));
r += one;
BUG_ON(v.counter != r);
#ifdef CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
INIT(onestwos);
BUG_ON(atomic64_dec_if_positive(&v) != (onestwos - 1));
r -= one;
BUG_ON(v.counter != r);
INIT(0);
BUG_ON(atomic64_dec_if_positive(&v) != -one);
BUG_ON(v.counter != r);
INIT(-one);
BUG_ON(atomic64_dec_if_positive(&v) != (-one - one));
BUG_ON(v.counter != r);
#else
#warning Please implement atomic64_dec_if_positive for your architecture and select the above Kconfig symbol
#endif
INIT(onestwos);
BUG_ON(!atomic64_inc_not_zero(&v));
r += one;
BUG_ON(v.counter != r);
INIT(0);
BUG_ON(atomic64_inc_not_zero(&v));
BUG_ON(v.counter != r);
INIT(-one);
BUG_ON(!atomic64_inc_not_zero(&v));
r += one;
BUG_ON(v.counter != r);
#ifdef CONFIG_X86
pr_info("passed for %s platform %s CX8 and %s SSE\n",
#ifdef CONFIG_X86_64
"x86-64",
#elif defined(CONFIG_X86_CMPXCHG64)
"i586+",
#else
"i386+",
#endif
boot_cpu_has(X86_FEATURE_CX8) ? "with" : "without",
boot_cpu_has(X86_FEATURE_XMM) ? "with" : "without");
#else
pr_info("passed\n");
#endif
return 0;
}
static bool test_ptsc(int idx)
{
return boot_cpu_has(X86_FEATURE_PTSC);
}
static bool test_therm_status(int idx)
{
return boot_cpu_has(X86_FEATURE_DTHERM);
}