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-rw-r--r--arch/x86/kernel/alternative.c36
-rw-r--r--arch/x86/kernel/cpu/amd.c9
-rw-r--r--arch/x86/kernel/cpu/centaur.c11
-rw-r--r--arch/x86/kernel/cpu/common.c34
-rw-r--r--arch/x86/kernel/cpu/common_64.c74
-rw-r--r--arch/x86/kernel/cpu/cyrix.c32
-rw-r--r--arch/x86/kernel/cpu/feature_names.c3
-rw-r--r--arch/x86/kernel/cpuid.c15
-rw-r--r--arch/x86/kernel/e820.c2
-rw-r--r--arch/x86/kernel/hpet.c19
-rw-r--r--arch/x86/kernel/io_delay.c8
-rw-r--r--arch/x86/kernel/msr.c38
-rw-r--r--arch/x86/kernel/tsc.c234
13 files changed, 393 insertions, 122 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 2763cb37b55..65a0c1b4869 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -145,35 +145,25 @@ static const unsigned char *const p6_nops[ASM_NOP_MAX+1] = {
extern char __vsyscall_0;
const unsigned char *const *find_nop_table(void)
{
- return boot_cpu_data.x86_vendor != X86_VENDOR_INTEL ||
- boot_cpu_data.x86 < 6 ? k8_nops : p6_nops;
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
+ boot_cpu_has(X86_FEATURE_NOPL))
+ return p6_nops;
+ else
+ return k8_nops;
}
#else /* CONFIG_X86_64 */
-static const struct nop {
- int cpuid;
- const unsigned char *const *noptable;
-} noptypes[] = {
- { X86_FEATURE_K8, k8_nops },
- { X86_FEATURE_K7, k7_nops },
- { X86_FEATURE_P4, p6_nops },
- { X86_FEATURE_P3, p6_nops },
- { -1, NULL }
-};
-
const unsigned char *const *find_nop_table(void)
{
- const unsigned char *const *noptable = intel_nops;
- int i;
-
- for (i = 0; noptypes[i].cpuid >= 0; i++) {
- if (boot_cpu_has(noptypes[i].cpuid)) {
- noptable = noptypes[i].noptable;
- break;
- }
- }
- return noptable;
+ if (boot_cpu_has(X86_FEATURE_K8))
+ return k8_nops;
+ else if (boot_cpu_has(X86_FEATURE_K7))
+ return k7_nops;
+ else if (boot_cpu_has(X86_FEATURE_NOPL))
+ return p6_nops;
+ else
+ return intel_nops;
}
#endif /* CONFIG_X86_64 */
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index cae9cabc303..18514ed2610 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -31,6 +31,11 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
if (c->x86_power & (1<<8))
set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
}
+
+ /* Set MTRR capability flag if appropriate */
+ if (c->x86_model == 13 || c->x86_model == 9 ||
+ (c->x86_model == 8 && c->x86_mask >= 8))
+ set_cpu_cap(c, X86_FEATURE_K6_MTRR);
}
static void __cpuinit init_amd(struct cpuinfo_x86 *c)
@@ -166,10 +171,6 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
mbytes);
}
- /* Set MTRR capability flag if appropriate */
- if (c->x86_model == 13 || c->x86_model == 9 ||
- (c->x86_model == 8 && c->x86_mask >= 8))
- set_cpu_cap(c, X86_FEATURE_K6_MTRR);
break;
}
diff --git a/arch/x86/kernel/cpu/centaur.c b/arch/x86/kernel/cpu/centaur.c
index e0f45edd6a5..a0534c04d38 100644
--- a/arch/x86/kernel/cpu/centaur.c
+++ b/arch/x86/kernel/cpu/centaur.c
@@ -314,6 +314,16 @@ enum {
EAMD3D = 1<<20,
};
+static void __cpuinit early_init_centaur(struct cpuinfo_x86 *c)
+{
+ switch (c->x86) {
+ case 5:
+ /* Emulate MTRRs using Centaur's MCR. */
+ set_cpu_cap(c, X86_FEATURE_CENTAUR_MCR);
+ break;
+ }
+}
+
static void __cpuinit init_centaur(struct cpuinfo_x86 *c)
{
@@ -462,6 +472,7 @@ centaur_size_cache(struct cpuinfo_x86 *c, unsigned int size)
static struct cpu_dev centaur_cpu_dev __cpuinitdata = {
.c_vendor = "Centaur",
.c_ident = { "CentaurHauls" },
+ .c_early_init = early_init_centaur,
.c_init = init_centaur,
.c_size_cache = centaur_size_cache,
};
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 80ab20d4fa3..8aab8517642 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -13,6 +13,7 @@
#include <asm/mtrr.h>
#include <asm/mce.h>
#include <asm/pat.h>
+#include <asm/asm.h>
#ifdef CONFIG_X86_LOCAL_APIC
#include <asm/mpspec.h>
#include <asm/apic.h>
@@ -334,11 +335,40 @@ static void __init early_cpu_detect(void)
get_cpu_vendor(c, 1);
+ early_get_cap(c);
+
if (c->x86_vendor != X86_VENDOR_UNKNOWN &&
cpu_devs[c->x86_vendor]->c_early_init)
cpu_devs[c->x86_vendor]->c_early_init(c);
+}
- early_get_cap(c);
+/*
+ * The NOPL instruction is supposed to exist on all CPUs with
+ * family >= 6, unfortunately, that's not true in practice because
+ * of early VIA chips and (more importantly) broken virtualizers that
+ * are not easy to detect. Hence, probe for it based on first
+ * principles.
+ */
+static void __cpuinit detect_nopl(struct cpuinfo_x86 *c)
+{
+ const u32 nopl_signature = 0x888c53b1; /* Random number */
+ u32 has_nopl = nopl_signature;
+
+ clear_cpu_cap(c, X86_FEATURE_NOPL);
+ if (c->x86 >= 6) {
+ asm volatile("\n"
+ "1: .byte 0x0f,0x1f,0xc0\n" /* nopl %eax */
+ "2:\n"
+ " .section .fixup,\"ax\"\n"
+ "3: xor %0,%0\n"
+ " jmp 2b\n"
+ " .previous\n"
+ _ASM_EXTABLE(1b,3b)
+ : "+a" (has_nopl));
+
+ if (has_nopl == nopl_signature)
+ set_cpu_cap(c, X86_FEATURE_NOPL);
+ }
}
static void __cpuinit generic_identify(struct cpuinfo_x86 *c)
@@ -395,8 +425,8 @@ static void __cpuinit generic_identify(struct cpuinfo_x86 *c)
}
init_scattered_cpuid_features(c);
+ detect_nopl(c);
}
-
}
static void __cpuinit squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
diff --git a/arch/x86/kernel/cpu/common_64.c b/arch/x86/kernel/cpu/common_64.c
index dd6e3f15017..a11f5d4477c 100644
--- a/arch/x86/kernel/cpu/common_64.c
+++ b/arch/x86/kernel/cpu/common_64.c
@@ -18,6 +18,7 @@
#include <asm/mtrr.h>
#include <asm/mce.h>
#include <asm/pat.h>
+#include <asm/asm.h>
#include <asm/numa.h>
#ifdef CONFIG_X86_LOCAL_APIC
#include <asm/mpspec.h>
@@ -215,6 +216,39 @@ static void __init early_cpu_support_print(void)
}
}
+/*
+ * The NOPL instruction is supposed to exist on all CPUs with
+ * family >= 6, unfortunately, that's not true in practice because
+ * of early VIA chips and (more importantly) broken virtualizers that
+ * are not easy to detect. Hence, probe for it based on first
+ * principles.
+ *
+ * Note: no 64-bit chip is known to lack these, but put the code here
+ * for consistency with 32 bits, and to make it utterly trivial to
+ * diagnose the problem should it ever surface.
+ */
+static void __cpuinit detect_nopl(struct cpuinfo_x86 *c)
+{
+ const u32 nopl_signature = 0x888c53b1; /* Random number */
+ u32 has_nopl = nopl_signature;
+
+ clear_cpu_cap(c, X86_FEATURE_NOPL);
+ if (c->x86 >= 6) {
+ asm volatile("\n"
+ "1: .byte 0x0f,0x1f,0xc0\n" /* nopl %eax */
+ "2:\n"
+ " .section .fixup,\"ax\"\n"
+ "3: xor %0,%0\n"
+ " jmp 2b\n"
+ " .previous\n"
+ _ASM_EXTABLE(1b,3b)
+ : "+a" (has_nopl));
+
+ if (has_nopl == nopl_signature)
+ set_cpu_cap(c, X86_FEATURE_NOPL);
+ }
+}
+
static void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c);
void __init early_cpu_init(void)
@@ -313,6 +347,8 @@ static void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c)
c->x86_phys_bits = eax & 0xff;
}
+ detect_nopl(c);
+
if (c->x86_vendor != X86_VENDOR_UNKNOWN &&
cpu_devs[c->x86_vendor]->c_early_init)
cpu_devs[c->x86_vendor]->c_early_init(c);
@@ -493,17 +529,20 @@ void pda_init(int cpu)
/* others are initialized in smpboot.c */
pda->pcurrent = &init_task;
pda->irqstackptr = boot_cpu_stack;
+ pda->irqstackptr += IRQSTACKSIZE - 64;
} else {
- pda->irqstackptr = (char *)
- __get_free_pages(GFP_ATOMIC, IRQSTACK_ORDER);
- if (!pda->irqstackptr)
- panic("cannot allocate irqstack for cpu %d", cpu);
+ if (!pda->irqstackptr) {
+ pda->irqstackptr = (char *)
+ __get_free_pages(GFP_ATOMIC, IRQSTACK_ORDER);
+ if (!pda->irqstackptr)
+ panic("cannot allocate irqstack for cpu %d",
+ cpu);
+ pda->irqstackptr += IRQSTACKSIZE - 64;
+ }
if (pda->nodenumber == 0 && cpu_to_node(cpu) != NUMA_NO_NODE)
pda->nodenumber = cpu_to_node(cpu);
}
-
- pda->irqstackptr += IRQSTACKSIZE-64;
}
char boot_exception_stacks[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ +
@@ -601,19 +640,22 @@ void __cpuinit cpu_init(void)
/*
* set up and load the per-CPU TSS
*/
- for (v = 0; v < N_EXCEPTION_STACKS; v++) {
+ if (!orig_ist->ist[0]) {
static const unsigned int order[N_EXCEPTION_STACKS] = {
- [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STACK_ORDER,
- [DEBUG_STACK - 1] = DEBUG_STACK_ORDER
+ [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STACK_ORDER,
+ [DEBUG_STACK - 1] = DEBUG_STACK_ORDER
};
- if (cpu) {
- estacks = (char *)__get_free_pages(GFP_ATOMIC, order[v]);
- if (!estacks)
- panic("Cannot allocate exception stack %ld %d\n",
- v, cpu);
+ for (v = 0; v < N_EXCEPTION_STACKS; v++) {
+ if (cpu) {
+ estacks = (char *)__get_free_pages(GFP_ATOMIC, order[v]);
+ if (!estacks)
+ panic("Cannot allocate exception "
+ "stack %ld %d\n", v, cpu);
+ }
+ estacks += PAGE_SIZE << order[v];
+ orig_ist->ist[v] = t->x86_tss.ist[v] =
+ (unsigned long)estacks;
}
- estacks += PAGE_SIZE << order[v];
- orig_ist->ist[v] = t->x86_tss.ist[v] = (unsigned long)estacks;
}
t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
diff --git a/arch/x86/kernel/cpu/cyrix.c b/arch/x86/kernel/cpu/cyrix.c
index e710a21bb6e..898a5a2002e 100644
--- a/arch/x86/kernel/cpu/cyrix.c
+++ b/arch/x86/kernel/cpu/cyrix.c
@@ -15,13 +15,11 @@
/*
* Read NSC/Cyrix DEVID registers (DIR) to get more detailed info. about the CPU
*/
-static void __cpuinit do_cyrix_devid(unsigned char *dir0, unsigned char *dir1)
+static void __cpuinit __do_cyrix_devid(unsigned char *dir0, unsigned char *dir1)
{
unsigned char ccr2, ccr3;
- unsigned long flags;
/* we test for DEVID by checking whether CCR3 is writable */
- local_irq_save(flags);
ccr3 = getCx86(CX86_CCR3);
setCx86(CX86_CCR3, ccr3 ^ 0x80);
getCx86(0xc0); /* dummy to change bus */
@@ -44,9 +42,16 @@ static void __cpuinit do_cyrix_devid(unsigned char *dir0, unsigned char *dir1)
*dir0 = getCx86(CX86_DIR0);
*dir1 = getCx86(CX86_DIR1);
}
- local_irq_restore(flags);
}
+static void __cpuinit do_cyrix_devid(unsigned char *dir0, unsigned char *dir1)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __do_cyrix_devid(dir0, dir1);
+ local_irq_restore(flags);
+}
/*
* Cx86_dir0_msb is a HACK needed by check_cx686_cpuid/slop in bugs.h in
* order to identify the Cyrix CPU model after we're out of setup.c
@@ -161,6 +166,24 @@ static void __cpuinit geode_configure(void)
local_irq_restore(flags);
}
+static void __cpuinit early_init_cyrix(struct cpuinfo_x86 *c)
+{
+ unsigned char dir0, dir0_msn, dir1 = 0;
+
+ __do_cyrix_devid(&dir0, &dir1);
+ dir0_msn = dir0 >> 4; /* identifies CPU "family" */
+
+ switch (dir0_msn) {
+ case 3: /* 6x86/6x86L */
+ /* Emulate MTRRs using Cyrix's ARRs. */
+ set_cpu_cap(c, X86_FEATURE_CYRIX_ARR);
+ break;
+ case 5: /* 6x86MX/M II */
+ /* Emulate MTRRs using Cyrix's ARRs. */
+ set_cpu_cap(c, X86_FEATURE_CYRIX_ARR);
+ break;
+ }
+}
static void __cpuinit init_cyrix(struct cpuinfo_x86 *c)
{
@@ -416,6 +439,7 @@ static void __cpuinit cyrix_identify(struct cpuinfo_x86 *c)
static struct cpu_dev cyrix_cpu_dev __cpuinitdata = {
.c_vendor = "Cyrix",
.c_ident = { "CyrixInstead" },
+ .c_early_init = early_init_cyrix,
.c_init = init_cyrix,
.c_identify = cyrix_identify,
};
diff --git a/arch/x86/kernel/cpu/feature_names.c b/arch/x86/kernel/cpu/feature_names.c
index e43ad4ad4cb..c9017799497 100644
--- a/arch/x86/kernel/cpu/feature_names.c
+++ b/arch/x86/kernel/cpu/feature_names.c
@@ -39,7 +39,8 @@ const char * const x86_cap_flags[NCAPINTS*32] = {
NULL, NULL, NULL, NULL,
"constant_tsc", "up", NULL, "arch_perfmon",
"pebs", "bts", NULL, NULL,
- "rep_good", NULL, NULL, NULL, NULL, NULL, NULL, NULL,
+ "rep_good", NULL, NULL, NULL,
+ "nopl", NULL, NULL, NULL,
NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
/* Intel-defined (#2) */
diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c
index 14b11b3be31..8e9cd6a8ec1 100644
--- a/arch/x86/kernel/cpuid.c
+++ b/arch/x86/kernel/cpuid.c
@@ -89,6 +89,8 @@ static ssize_t cpuid_read(struct file *file, char __user *buf,
struct cpuid_regs cmd;
int cpu = iminor(file->f_path.dentry->d_inode);
u64 pos = *ppos;
+ ssize_t bytes = 0;
+ int err = 0;
if (count % 16)
return -EINVAL; /* Invalid chunk size */
@@ -96,14 +98,19 @@ static ssize_t cpuid_read(struct file *file, char __user *buf,
for (; count; count -= 16) {
cmd.eax = pos;
cmd.ecx = pos >> 32;
- smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1);
- if (copy_to_user(tmp, &cmd, 16))
- return -EFAULT;
+ err = smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1);
+ if (err)
+ break;
+ if (copy_to_user(tmp, &cmd, 16)) {
+ err = -EFAULT;
+ break;
+ }
tmp += 16;
+ bytes += 16;
*ppos = ++pos;
}
- return tmp - buf;
+ return bytes ? bytes : err;
}
static int cpuid_open(struct inode *inode, struct file *file)
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 9af89078f7b..66e48aa2dd1 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -1203,7 +1203,7 @@ static int __init parse_memmap_opt(char *p)
if (!p)
return -EINVAL;
- if (!strcmp(p, "exactmap")) {
+ if (!strncmp(p, "exactmap", 8)) {
#ifdef CONFIG_CRASH_DUMP
/*
* If we are doing a crash dump, we still need to know
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 59fd3b6b130..73deaffadd0 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -210,8 +210,8 @@ static void hpet_legacy_clockevent_register(void)
/* Calculate the min / max delta */
hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF,
&hpet_clockevent);
- hpet_clockevent.min_delta_ns = clockevent_delta2ns(0x30,
- &hpet_clockevent);
+ /* 5 usec minimum reprogramming delta. */
+ hpet_clockevent.min_delta_ns = 5000;
/*
* Start hpet with the boot cpu mask and make it
@@ -270,15 +270,22 @@ static void hpet_legacy_set_mode(enum clock_event_mode mode,
}
static int hpet_legacy_next_event(unsigned long delta,
- struct clock_event_device *evt)
+ struct clock_event_device *evt)
{
- unsigned long cnt;
+ u32 cnt;
cnt = hpet_readl(HPET_COUNTER);
- cnt += delta;
+ cnt += (u32) delta;
hpet_writel(cnt, HPET_T0_CMP);
- return ((long)(hpet_readl(HPET_COUNTER) - cnt ) > 0) ? -ETIME : 0;
+ /*
+ * We need to read back the CMP register to make sure that
+ * what we wrote hit the chip before we compare it to the
+ * counter.
+ */
+ WARN_ON((u32)hpet_readl(HPET_T0_CMP) != cnt);
+
+ return (s32)((u32)hpet_readl(HPET_COUNTER) - cnt) >= 0 ? -ETIME : 0;
}
/*
diff --git a/arch/x86/kernel/io_delay.c b/arch/x86/kernel/io_delay.c
index 1c3a66a67f8..720d2607aac 100644
--- a/arch/x86/kernel/io_delay.c
+++ b/arch/x86/kernel/io_delay.c
@@ -92,6 +92,14 @@ static struct dmi_system_id __initdata io_delay_0xed_port_dmi_table[] = {
DMI_MATCH(DMI_BOARD_NAME, "30BF")
}
},
+ {
+ .callback = dmi_io_delay_0xed_port,
+ .ident = "Presario F700",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Quanta"),
+ DMI_MATCH(DMI_BOARD_NAME, "30D3")
+ }
+ },
{ }
};
diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c
index e4393808688..2e2af5d1819 100644
--- a/arch/x86/kernel/msr.c
+++ b/arch/x86/kernel/msr.c
@@ -72,21 +72,28 @@ static ssize_t msr_read(struct file *file, char __user *buf,
u32 data[2];
u32 reg = *ppos;
int cpu = iminor(file->f_path.dentry->d_inode);
- int err;
+ int err = 0;
+ ssize_t bytes = 0;
if (count % 8)
return -EINVAL; /* Invalid chunk size */
for (; count; count -= 8) {
err = rdmsr_safe_on_cpu(cpu, reg, &data[0], &data[1]);
- if (err)
- return -EIO;
- if (copy_to_user(tmp, &data, 8))
- return -EFAULT;
+ if (err) {
+ if (err == -EFAULT) /* Fix idiotic error code */
+ err = -EIO;
+ break;
+ }
+ if (copy_to_user(tmp, &data, 8)) {
+ err = -EFAULT;
+ break;
+ }
tmp += 2;
+ bytes += 8;
}
- return ((char __user *)tmp) - buf;
+ return bytes ? bytes : err;
}
static ssize_t msr_write(struct file *file, const char __user *buf,
@@ -96,21 +103,28 @@ static ssize_t msr_write(struct file *file, const char __user *buf,
u32 data[2];
u32 reg = *ppos;
int cpu = iminor(file->f_path.dentry->d_inode);
- int err;
+ int err = 0;
+ ssize_t bytes = 0;
if (count % 8)
return -EINVAL; /* Invalid chunk size */
for (; count; count -= 8) {
- if (copy_from_user(&data, tmp, 8))
- return -EFAULT;
+ if (copy_from_user(&data, tmp, 8)) {
+ err = -EFAULT;
+ break;
+ }
err = wrmsr_safe_on_cpu(cpu, reg, data[0], data[1]);
- if (err)
- return -EIO;
+ if (err) {
+ if (err == -EFAULT) /* Fix idiotic error code */
+ err = -EIO;
+ break;
+ }
tmp += 2;
+ bytes += 8;
}
- return ((char __user *)tmp) - buf;
+ return bytes ? bytes : err;
}
static int msr_open(struct inode *inode, struct file *file)
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 8e786b0d665..8f98e9de1b8 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -122,80 +122,216 @@ static u64 tsc_read_refs(u64 *pm, u64 *hpet)
return ULLONG_MAX;
}
-/**
- * native_calibrate_tsc - calibrate the tsc on boot
+/*
+ * Try to calibrate the TSC against the Programmable
+ * Interrupt Timer and return the frequency of the TSC
+ * in kHz.
+ *
+ * Return ULONG_MAX on failure to calibrate.
*/
-unsigned long native_calibrate_tsc(void)
+static unsigned long pit_calibrate_tsc(void)
{
- unsigned long flags;
- u64 tsc1, tsc2, tr1, tr2, delta, pm1, pm2, hpet1, hpet2;
- int hpet = is_hpet_enabled();
- unsigned int tsc_khz_val = 0;
-
- local_irq_save(flags);
-
- tsc1 = tsc_read_refs(&pm1, hpet ? &hpet1 : NULL);
+ u64 tsc, t1, t2, delta;
+ unsigned long tscmin, tscmax;
+ int pitcnt;
+ /* Set the Gate high, disable speaker */
outb((inb(0x61) & ~0x02) | 0x01, 0x61);
+ /*
+ * Setup CTC channel 2* for mode 0, (interrupt on terminal
+ * count mode), binary count. Set the latch register to 50ms
+ * (LSB then MSB) to begin countdown.
+ */
outb(0xb0, 0x43);
outb((CLOCK_TICK_RATE / (1000 / 50)) & 0xff, 0x42);
outb((CLOCK_TICK_RATE / (1000 / 50)) >> 8, 0x42);
- tr1 = get_cycles();
- while ((inb(0x61) & 0x20) == 0);
- tr2 = get_cycles();
- tsc2 = tsc_read_refs(&pm2, hpet ? &hpet2 : NULL);
+ tsc = t1 = t2 = get_cycles();
- local_irq_restore(flags);
+ pitcnt = 0;
+ tscmax = 0;
+ tscmin = ULONG_MAX;
+ while ((inb(0x61) & 0x20) == 0) {
+ t2 = get_cycles();
+ delta = t2 - tsc;
+ tsc = t2;
+ if ((unsigned long) delta < tscmin)
+ tscmin = (unsigned int) delta;
+ if ((unsigned long) delta > tscmax)
+ tscmax = (unsigned int) delta;
+ pitcnt++;
+ }
/*
- * Preset the result with the raw and inaccurate PIT
- * calibration value
+ * Sanity checks:
+ *
+ * If we were not able to read the PIT more than 5000
+ * times, then we have been hit by a massive SMI
+ *
+ * If the maximum is 10 times larger than the minimum,
+ * then we got hit by an SMI as well.
*/
- delta = (tr2 - tr1);
+ if (pitcnt < 5000 || tscmax > 10 * tscmin)
+ return ULONG_MAX;
+
+ /* Calculate the PIT value */
+ delta = t2 - t1;
do_div(delta, 50);
- tsc_khz_val = delta;
+ return delta;
+}
+
+
+/**
+ * native_calibrate_tsc - calibrate the tsc on boot
+ */
+unsigned long native_calibrate_tsc(void)
+{
+ u64 tsc1, tsc2, delta, pm1, pm2, hpet1, hpet2;
+ unsigned long tsc_pit_min = ULONG_MAX, tsc_ref_min = ULONG_MAX;
+ unsigned long flags;
+ int hpet = is_hpet_enabled(), i;
- /* hpet or pmtimer available ? */
+ /*
+ * Run 5 calibration loops to get the lowest frequency value
+ * (the best estimate). We use two different calibration modes
+ * here:
+ *
+ * 1) PIT loop. We set the PIT Channel 2 to oneshot mode and
+ * load a timeout of 50ms. We read the time right after we
+ * started the timer and wait until the PIT count down reaches
+ * zero. In each wait loop iteration we read the TSC and check
+ * the delta to the previous read. We keep track of the min
+ * and max values of that delta. The delta is mostly defined
+ * by the IO time of the PIT access, so we can detect when a
+ * SMI/SMM disturbance happend between the two reads. If the
+ * maximum time is significantly larger than the minimum time,
+ * then we discard the result and have another try.
+ *
+ * 2) Reference counter. If available we use the HPET or the
+ * PMTIMER as a reference to check the sanity of that value.
+ * We use separate TSC readouts and check inside of the
+ * reference read for a SMI/SMM disturbance. We dicard
+ * disturbed values here as well. We do that around the PIT
+ * calibration delay loop as we have to wait for a certain
+ * amount of time anyway.
+ */
+ for (i = 0; i < 5; i++) {
+ unsigned long tsc_pit_khz;
+
+ /*
+ * Read the start value and the reference count of
+ * hpet/pmtimer when available. Then do the PIT
+ * calibration, which will take at least 50ms, and
+ * read the end value.
+ */
+ local_irq_save(flags);
+ tsc1 = tsc_read_refs(&pm1, hpet ? &hpet1 : NULL);
+ tsc_pit_khz = pit_calibrate_tsc();
+ tsc2 = tsc_read_refs(&pm2, hpet ? &hpet2 : NULL);
+ local_irq_restore(flags);
+
+ /* Pick the lowest PIT TSC calibration so far */
+ tsc_pit_min = min(tsc_pit_min, tsc_pit_khz);
+
+ /* hpet or pmtimer available ? */
+ if (!hpet && !pm1 && !pm2)
+ continue;
+
+ /* Check, whether the sampling was disturbed by an SMI */
+ if (tsc1 == ULLONG_MAX || tsc2 == ULLONG_MAX)
+ continue;
+
+ tsc2 = (tsc2 - tsc1) * 1000000LL;
+
+ if (hpet) {
+ if (hpet2 < hpet1)
+ hpet2 += 0x100000000ULL;
+ hpet2 -= hpet1;
+ tsc1 = ((u64)hpet2 * hpet_readl(HPET_PERIOD));
+ do_div(tsc1, 1000000);
+ } else {
+ if (pm2 < pm1)
+ pm2 += (u64)ACPI_PM_OVRRUN;
+ pm2 -= pm1;
+ tsc1 = pm2 * 1000000000LL;
+ do_div(tsc1, PMTMR_TICKS_PER_SEC);
+ }
+
+ do_div(tsc2, tsc1);
+ tsc_ref_min = min(tsc_ref_min, (unsigned long) tsc2);
+ }
+
+ /*
+ * Now check the results.
+ */
+ if (tsc_pit_min == ULONG_MAX) {
+ /* PIT gave no useful value */
+ printk(KERN_WARNING "TSC: Unable to calibrate against PIT\n");
+
+ /* We don't have an alternative source, disable TSC */
+ if (!hpet && !pm1 && !pm2) {
+ printk("TSC: No reference (HPET/PMTIMER) available\n");
+ return 0;
+ }
+
+ /* The alternative source failed as well, disable TSC */
+ if (tsc_ref_min == ULONG_MAX) {
+ printk(KERN_WARNING "TSC: HPET/PMTIMER calibration "
+ "failed due to SMI disturbance.\n");
+ return 0;
+ }
+
+ /* Use the alternative source */
+ printk(KERN_INFO "TSC: using %s reference calibration\n",
+ hpet ? "HPET" : "PMTIMER");
+
+ return tsc_ref_min;
+ }
+
+ /* We don't have an alternative source, use the PIT calibration value */
if (!hpet && !pm1 && !pm2) {
- printk(KERN_INFO "TSC calibrated against PIT\n");
- goto out;
+ printk(KERN_INFO "TSC: Using PIT calibration value\n");
+ return tsc_pit_min;
}
- /* Check, whether the sampling was disturbed by an SMI */
- if (tsc1 == ULLONG_MAX || tsc2 == ULLONG_MAX) {
- printk(KERN_WARNING "TSC calibration disturbed by SMI, "
- "using PIT calibration result\n");
- goto out;
+ /* The alternative source failed, use the PIT calibration value */
+ if (tsc_ref_min == ULONG_MAX) {
+ printk(KERN_WARNING "TSC: HPET/PMTIMER calibration failed due "
+ "to SMI disturbance. Using PIT calibration\n");
+ return tsc_pit_min;
}
- tsc2 = (tsc2 - tsc1) * 1000000LL;
-
- if (hpet) {
- printk(KERN_INFO "TSC calibrated against HPET\n");
- if (hpet2 < hpet1)
- hpet2 += 0x100000000ULL;
- hpet2 -= hpet1;
- tsc1 = ((u64)hpet2 * hpet_readl(HPET_PERIOD));
- do_div(tsc1, 1000000);
- } else {
- printk(KERN_INFO "TSC calibrated against PM_TIMER\n");
- if (pm2 < pm1)
- pm2 += (u64)ACPI_PM_OVRRUN;
- pm2 -= pm1;
- tsc1 = pm2 * 1000000000LL;
- do_div(tsc1, PMTMR_TICKS_PER_SEC);
+ /* Check the reference deviation */
+ delta = ((u64) tsc_pit_min) * 100;
+ do_div(delta, tsc_ref_min);
+
+ /*
+ * If both calibration results are inside a 5% window, the we
+ * use the lower frequency of those as it is probably the
+ * closest estimate.
+ */
+ if (delta >= 95 && delta <= 105) {
+ printk(KERN_INFO "TSC: PIT calibration confirmed by %s.\n",
+ hpet ? "HPET" : "PMTIMER");
+ printk(KERN_INFO "TSC: using %s calibration value\n",
+ tsc_pit_min <= tsc_ref_min ? "PIT" :
+ hpet ? "HPET" : "PMTIMER");
+ return tsc_pit_min <= tsc_ref_min ? tsc_pit_min : tsc_ref_min;
}
- do_div(tsc2, tsc1);
- tsc_khz_val = tsc2;
+ printk(KERN_WARNING "TSC: PIT calibration deviates from %s: %lu %lu.\n",
+ hpet ? "HPET" : "PMTIMER", tsc_pit_min, tsc_ref_min);
-out:
- return tsc_khz_val;
+ /*
+ * The calibration values differ too much. In doubt, we use
+ * the PIT value as we know that there are PMTIMERs around
+ * running at double speed.
+ */
+ printk(KERN_INFO "TSC: Using PIT calibration value\n");
+ return tsc_pit_min;
}
-
#ifdef CONFIG_X86_32
/* Only called from the Powernow K7 cpu freq driver */
int recalibrate_cpu_khz(void)
generated by cgit (git 2.34.1) at 2024-11-20 01:18:18 +0000