* use the TSC value at the transitions to calculate a pretty
* good value for the TSC frequencty.
*/
- static inline int pit_expect_msb(unsigned char val)
+ static inline int pit_expect_msb(unsigned char val, u64 *tscp, unsigned long *deltap)
{
- int count = 0;
+ int count;
+ u64 tsc = 0;
for (count = 0; count < 50000; count++) {
/* Ignore LSB */
inb(0x42);
if (inb(0x42) != val)
break;
+ tsc = get_cycles();
}
- return count > 50;
+ *deltap = get_cycles() - tsc;
+ *tscp = tsc;
+
+ /*
+ * We require _some_ success, but the quality control
+ * will be based on the error terms on the TSC values.
+ */
+ return count > 5;
}
/*
- * How many MSB values do we want to see? We aim for a
- * 15ms calibration, which assuming a 2us counter read
- * error should give us roughly 150 ppm precision for
- * the calibration.
+ * How many MSB values do we want to see? We aim for
+ * a maximum error rate of 500ppm (in practice the
+ * real error is much smaller), but refuse to spend
+ * more than 25ms on it.
*/
- #define QUICK_PIT_MS 15
- #define QUICK_PIT_ITERATIONS (QUICK_PIT_MS * PIT_TICK_RATE / 1000 / 256)
+ #define MAX_QUICK_PIT_MS 25
+ #define MAX_QUICK_PIT_ITERATIONS (MAX_QUICK_PIT_MS * PIT_TICK_RATE / 1000 / 256)
static unsigned long quick_pit_calibrate(void)
{
+ int i;
+ u64 tsc, delta;
+ unsigned long d1, d2;
+
/* Set the Gate high, disable speaker */
outb((inb(0x61) & ~0x02) | 0x01, 0x61);
outb(0xff, 0x42);
outb(0xff, 0x42);
- if (pit_expect_msb(0xff)) {
- int i;
- u64 t1, t2, delta;
- unsigned char expect = 0xfe;
-
- t1 = get_cycles();
- for (i = 0; i < QUICK_PIT_ITERATIONS; i++, expect--) {
- if (!pit_expect_msb(expect))
- goto failed;
+ /*
+ * The PIT starts counting at the next edge, so we
+ * need to delay for a microsecond. The easiest way
+ * to do that is to just read back the 16-bit counter
+ * once from the PIT.
+ */
+ inb(0x42);
+ inb(0x42);
+
+ if (pit_expect_msb(0xff, &tsc, &d1)) {
+ for (i = 1; i <= MAX_QUICK_PIT_ITERATIONS; i++) {
+ if (!pit_expect_msb(0xff-i, &delta, &d2))
+ break;
+
+ /*
+ * Iterate until the error is less than 500 ppm
+ */
+ delta -= tsc;
+ if (d1+d2 < delta >> 11)
+ goto success;
}
- t2 = get_cycles();
-
- /*
- * Make sure we can rely on the second TSC timestamp:
- */
- if (!pit_expect_msb(expect))
- goto failed;
-
- /*
- * Ok, if we get here, then we've seen the
- * MSB of the PIT decrement QUICK_PIT_ITERATIONS
- * times, and each MSB had many hits, so we never
- * had any sudden jumps.
- *
- * As a result, we can depend on there not being
- * any odd delays anywhere, and the TSC reads are
- * reliable.
- *
- * kHz = ticks / time-in-seconds / 1000;
- * kHz = (t2 - t1) / (QPI * 256 / PIT_TICK_RATE) / 1000
- * kHz = ((t2 - t1) * PIT_TICK_RATE) / (QPI * 256 * 1000)
- */
- delta = (t2 - t1)*PIT_TICK_RATE;
- do_div(delta, QUICK_PIT_ITERATIONS*256*1000);
- printk("Fast TSC calibration using PIT\n");
- return delta;
}
- failed:
+ printk("Fast TSC calibration failed\n");
return 0;
+
+ success:
+ /*
+ * Ok, if we get here, then we've seen the
+ * MSB of the PIT decrement 'i' times, and the
+ * error has shrunk to less than 500 ppm.
+ *
+ * As a result, we can depend on there not being
+ * any odd delays anywhere, and the TSC reads are
+ * reliable (within the error). We also adjust the
+ * delta to the middle of the error bars, just
+ * because it looks nicer.
+ *
+ * kHz = ticks / time-in-seconds / 1000;
+ * kHz = (t2 - t1) / (I * 256 / PIT_TICK_RATE) / 1000
+ * kHz = ((t2 - t1) * PIT_TICK_RATE) / (I * 256 * 1000)
+ */
+ delta += (long)(d2 - d1)/2;
+ delta *= PIT_TICK_RATE;
+ do_div(delta, i*256*1000);
+ printk("Fast TSC calibration using PIT\n");
+ return delta;
}
/**
if (!cpu_has_tsc || tsc_unstable)
return 1;
-#ifdef CONFIG_X86_SMP
+#ifdef CONFIG_SMP
if (apic_is_clustered_box())
return 1;
#endif
}
EXPORT_SYMBOL_GPL(acpi_os_map_memory);
-void acpi_os_unmap_memory(void __iomem * virt, acpi_size size)
+void __ref acpi_os_unmap_memory(void __iomem *virt, acpi_size size)
{
- if (acpi_gbl_permanent_mmap) {
+ if (acpi_gbl_permanent_mmap)
iounmap(virt);
- }
+ else
+ __acpi_unmap_table(virt, size);
}
EXPORT_SYMBOL_GPL(acpi_os_unmap_memory);
+void __init early_acpi_os_unmap_memory(void __iomem *virt, acpi_size size)
+{
+ if (!acpi_gbl_permanent_mmap)
+ __acpi_unmap_table(virt, size);
+}
+
#ifdef ACPI_FUTURE_USAGE
acpi_status
acpi_os_get_physical_address(void *virt, acpi_physical_address * phys)
return AE_SUPPORT;
}
- #ifdef CONFIG_X86
-
- struct aml_port_desc {
- uint start;
- uint end;
- char* name;
- char warned;
- };
-
- static struct aml_port_desc aml_invalid_port_list[] = {
- {0x20, 0x21, "PIC0", 0},
- {0xA0, 0xA1, "PIC1", 0},
- {0x4D0, 0x4D1, "ELCR", 0}
- };
-
- /*
- * valid_aml_io_address()
- *
- * if valid, return true
- * else invalid, warn once, return false
- */
- static bool valid_aml_io_address(uint address, uint length)
- {
- int i;
- int entries = sizeof(aml_invalid_port_list) / sizeof(struct aml_port_desc);
-
- for (i = 0; i < entries; ++i) {
- if ((address >= aml_invalid_port_list[i].start &&
- address <= aml_invalid_port_list[i].end) ||
- (address + length >= aml_invalid_port_list[i].start &&
- address + length <= aml_invalid_port_list[i].end))
- {
- if (!aml_invalid_port_list[i].warned)
- {
- printk(KERN_ERR "ACPI: Denied BIOS AML access"
- " to invalid port 0x%x+0x%x (%s)\n",
- address, length,
- aml_invalid_port_list[i].name);
- aml_invalid_port_list[i].warned = 1;
- }
- return false; /* invalid */
- }
- }
- return true; /* valid */
- }
- #else
- static inline bool valid_aml_io_address(uint address, uint length) { return true; }
- #endif
/******************************************************************************
*
* FUNCTION: acpi_os_validate_address
switch (space_id) {
case ACPI_ADR_SPACE_SYSTEM_IO:
- if (!valid_aml_io_address(address, length))
- return AE_AML_ILLEGAL_ADDRESS;
case ACPI_ADR_SPACE_SYSTEM_MEMORY:
/* Only interference checks against SystemIO and SytemMemory
are needed */
projects / linux-2.6-omap-h63xx.git / commitdiff