So far the TSC timer driver supports trying hardware calibration first
and using device tree as last resort for its running frequency as the
normal timer.

However when it is used as the early timer, it only supports hardware
calibration and if it fails, the driver just panics. This introduces
a new config option to specify the early timer frequency in MHz and
it should be equal to the value described in the device tree.

Without this patch, the travis-ci testing on QEMU x86_64 target fails
each time after it finishes the 'bootefi selftest' as the test.py see
an error was emitted on the console like this:

  TSC frequency is ZERO
  resetting ...
  ### ERROR ### Please RESET the board ###

It's strange that this error is consistently seen on the travis-ci
machine, but only occasionally seen on my local machine (maybe 1 out
of 10). Since QEMU x86_64 target enables BOOTSTAGE support which uses
early timer, with this fix it should work without any failure.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

At present if TSC frequency is provided in the device tree, it takes
precedence over hardware calibration result. This swaps the order to
try hardware calibration first and uses device tree as last resort.

This can be helpful when a generic dts (eg: coreboot/efi payload) is
supposed to work on as many hardware as possible, including emulators
like QEMU where TSC hardware calibration sometimes fails.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>

With the introduction of early timer support in the TSC driver,
the capability of getting clock rate from device tree was lost
unfortunately. Now we bring such functionality back, but with a
limitation that when TSC is used as early timer, specifying clock
rate from device tree does not work.

This fixes random boot failures seen on QEMU targets: printing "TSC
frequency is ZERO" and reset forever.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

Starting with cpuid level 0x16 (Skylake-based processors)
it is possible to get CPU base freq via cpuid.

This fixes booting on a skylake based system.

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
[bmeng: fixed wrong indention of labels]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>

When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>

With bootstage we need access to the timer before driver model is set up.
To handle this, put the required state in global_data and provide a new
function to set up the device, separate from the driver's probe() method.

This will be used by the 'early' timer also.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

Per the Intel 64 and IA-32 Architecture Software Developer's Manual,
add the reference clock for Intel Atom Processors based on the Airmont
Microarchitecture (Braswell).

This keeps in sync with Linux kernel commit:
  6fcb41c: x86/tsc_msr: Add Airmont reference clock values

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

Rename try_msr_calibrate_tsc() to cpu_mhz_from_msr(), as that
better describes what the routine does.

This keeps in sync with Linux kernel commit:
  02c0cd2: x86/tsc_msr: Remove irqoff around MSR-based TSC enumeration

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

Atom processors use a 19.2 MHz crystal oscillator.

Early processors generate 100 MHz via 19.2 MHz * 26 / 5 = 99.84 MHz.

Later processors generate 100 MHz via 19.2 MHz * 125 / 24 = 100 MHz.

Update the Silvermont-based tables accordingly, matching the Software
Developers Manual.

Also, correct a 166 MHz entry that should have been 116 MHz, and add
a missing 80 MHz entry for VLV2.

This keeps in sync with Linux kernel commit:
  05680e7: x86/tsc_msr: Correct Silvermont reference clock values

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

Some processor abbreviations in the comments of freq_desc_tables[]
are obscure. This updates part of these to mention processors
that are known to us. Also expand frequency definitions.

This keeps in sync with Linux kernel commit:
  9e0cae9: x86/tsc_msr: Update comments, expand definitions

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

If either ratio or freq is zero, the return value is zero. There
is no need to create a fail branch and return zero there.

This keeps in sync with Linux kernel commit:
  14bb4e3: x86/tsc_msr: Remove debugging messages

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

try_msr_calibrate_tsc() is currently Intel-specific, and should not
execute on any other vendor's parts.

This keeps in sync with Linux kernel commit:
  ba82683: x86/tsc_msr: Identify Intel-specific code

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

Currently we read the tsc radio like this:

	ratio = (MSR_PLATFORM_INFO >> 8) & 0x1f;

Thus we get bit 8-12 of MSR_PLATFORM_INFO, however according to the
Intel manual, the ratio bits are bit 8-15.

Fix this problem by masking 0xff instead.

This keeps in sync with Linux kernel commit:
  886123f: x86/tsc: Read all ratio bits from MSR_PLATFORM_INFO

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

Right now i8254_init() is called from timer_init() in the tsc timer
driver. But actually i8254 and tsc are completely different things.
Since tsc timer has been converted to driver model, we should find
a new place that is appropriate for U-Boot to call i8254_init(),
which is now x86_cpu_init_f().

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>

To group all dm timer drivers together, move tsc timer to
drivers/timer directory.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>

Now that we have converted all x86 boards to use driver model timer,
remove these legacy timer codes in the tsc driver.

Note this also removes the TSC_CALIBRATION_BYPASS Kconfig option,
as it is not needed with driver model.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>

This adds driver model timer support to x86 tsc timer driver.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>

Replace __attribute__((no_instrument_function)) with notrace from
<linux/compiler.h>.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>

Rename pcat_timer.c to i8254.c and pcat_interrupts.c to i8259.c,
to match their header file names (i8254.h and i8259.h).

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>

When running SMP configuration on QEMU (tcg mode, no kvm), there is
a busy loop in start_aps(), calling udelay(), that waits for APs to
show up online. However, there is a chance that VCPU1 will be timeout
waiting, IOW the secondary VCPUs haven't started their execution yet.

This patch adds a 'pause' instruction in __udelay() only for QEMU
target, to give other VCPUs a chance to run. When QEMU sees the
'pause' instruction, it will yeild the execution to other CPUs.

Signed-off-by: Miao Yan <yanmiaobest@gmail.com>
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>

By default U-Boot automatically calibrates TSC running frequency via
MSR and PIT. The calibration may not work on every x86 processor, so
a new Kconfig option CONFIG_TSC_CALIBRATION_BYPASS is introduced to
allow bypassing the calibration and assign a hardcoded TSC frequency
CONFIG_TSC_FREQ_IN_MHZ.

Normally the bypass should be turned on in a simulation environment
like qemu.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>

Unfortunately MSR_FSB_FREQ is not available on this CPU, and the PIT method
seems to take up to 50ms which is much too long.

For this CPU we know the frequency, so add another special case for now.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

Return the saved TSC frequency in get_tbclk_mhz().

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>

Use the same way that Linux does for quick TSC calibration via PIT
when calibration via MSR fails.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>

Using MSR_PLATFORM_INFO (0xCE) to calibrate TSR will cause #GP on
processors which do not have this MSR. Instead only doing the MSR
calibration for known/supported CPUs.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>

Signed-off-by: Wolfgang Denk <wd@denx.de>
[trini: Fixup common/cmd_io.c]
Signed-off-by: Tom Rini <trini@ti.com>

Some changes are needed to x86 timer functions to support tracing. Add
these so that the feature works correctly.

Signed-off-by: Simon Glass <sjg@chromium.org>

While we don't want PCAT timers for timing, we want timer 2 so that we can
still make a beep. Re-purpose the PCAT driver for this, and enable it in
coreboot.

Signed-off-by: Simon Glass <sjg@chromium.org>

This timer runs at a rate that can be calculated, well over 100MHz. It is
ideal for accurate timing and does not need interrupt servicing.

Tidy up some old broken and unneeded implementations at the same time.

To provide a consistent view of boot time, we use the same time
base as coreboot. Use the base timestamp supplied by coreboot
as U-Boot's base time.

Signed-off-by: Simon Glass <sjg@chromium.org&gt;base>
Signed-off-by: Simon Glass <sjg@chromium.org>