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4fc600442b
Currently on for example on AMD Persimmon and ASRock E350M1 Linux
complains, that the PBLK length is invalid [1].
ACPI: Invalid PBLK length [0]
Consequently, frequency scaling might not work correctly, though for
these two boards it seems to work according to PowerTOP.
Indeed, according to the ACPI specification [2], setting PBlockLength
to 0 is only allowed if there is no PBlockAddress. Otherwise it has to
be set to 6.
18.5.93 Processor (Declare Processor)
[…]
PBlockAddress provides the system I/O address for the processors
register block. Each processor can supply a different such
address. PBlockLength is the length of the processor register
block, in bytes and is either 0 (for no P_BLK) or 6. With one
exception, all processors are required to have the same
PBlockLength. The exception is that the boot processor can have
a non-zero PBlockLength when all other processors have a zero
PBlockLength. It is valid for every processor to have a
PBlockLength of 0.
And that is exactly what Linux is checking in
`drivers/acpi/processor_driver.c` [3].
static int acpi_processor_get_info(struct acpi_device *device)
{
[…]
/*
* On some boxes several processors use the same processor bus id.
* But they are located in different scope. For example:
* \_SB.SCK0.CPU0
* \_SB.SCK1.CPU0
* Rename the processor device bus id. And the new bus id will be
* generated as the following format:
* CPU+CPU ID.
*/
sprintf(acpi_device_bid(device), "CPU%X", pr->id);
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
pr->acpi_id));
if (!object.processor.pblk_address)
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
else if (object.processor.pblk_length != 6)
printk(KERN_ERR PREFIX "Invalid PBLK length [%d]\n",
object.processor.pblk_length);
else {
pr->throttling.address = object.processor.pblk_address;
pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
pr->pblk = object.processor.pblk_address;
/*
* We don't care about error returns - we just try to mark
* these reserved so that nobody else is confused into thinking
* that this region might be unused..
*
* (In particular, allocating the IO range for Cardbus)
*/
request_region(pr->throttling.address, 6, "ACPI CPU throttle");
}
[…]
}
This issue has proliferated to all AMD based boards so fix it for
all of them by setting P_BLK length to 6.
The DSDT of for example AMD Parmer and AMD Thatcher also set it
to 6 everywhere so this solution is taken instead of setting the
P_BLK system I/O base to 0 for all but the first processor which
is how it is done for earlier AMD based boards.
As note having to set this manually should not be needed and
this should be autogenerated as done for most of the Intel boards
and the AMD K8 based boards (`src/cpu/amd/model_fxx/powernow_acpi.c`).
[1] http://www.coreboot.org/pipermail/coreboot/2013-January/073636.html
[2] http://acpi.info/DOWNLOADS/ACPIspec40a.pdf
[3] http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=blob;f=drivers/acpi/processor_driver.c;h=e83311bf1ebdaaaea1adbf2de1351cca907d3465;hb=5da1f88b8b727dc3a66c52d4513e871be6d43d19#l351
Tested-by: Paul Menzel <paulepanter@users.sourceforge.net>
• ASRock E350M1:
Tested-by: Paul Menzel <paulepanter@users.sourceforge.net>
• AMD Persimmon:
Tested-by: Martin Roth <martin.roth@se-eng.com>
Change-Id: Ie79fe4812532d124cc81747c75a4f3d88d00531c
Signed-off-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-on: http://review.coreboot.org/2189
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martin.roth@se-eng.com>
|
||
|---|---|---|
| 3rdparty@dac1a18d18 | ||
| documentation | ||
| payloads | ||
| src | ||
| util | ||
| .gitignore | ||
| .gitmodules | ||
| .gitreview | ||
| COPYING | ||
| Makefile | ||
| Makefile.inc | ||
| README | ||
------------------------------------------------------------------------------- coreboot README ------------------------------------------------------------------------------- coreboot is a Free Software project aimed at replacing the proprietary BIOS (firmware) found in most computers. coreboot performs a little bit of hardware initialization and then executes additional boot logic, called a payload. With the separation of hardware initialization and later boot logic, coreboot can scale from specialized applications that run directly firmware, run operating systems in flash, load custom bootloaders, or implement firmware standards, like PC BIOS services or UEFI. This allows for systems to only include the features necessary in the target application, reducing the amount of code and flash space required. coreboot was formerly known as LinuxBIOS. Payloads -------- After the basic initialization of the hardware has been performed, any desired "payload" can be started by coreboot. See http://www.coreboot.org/Payloads for a list of supported payloads. Supported Hardware ------------------ coreboot supports a wide range of chipsets, devices, and mainboards. For details please consult: * http://www.coreboot.org/Supported_Motherboards * http://www.coreboot.org/Supported_Chipsets_and_Devices Build Requirements ------------------ * gcc / g++ * make Optional: * doxygen (for generating/viewing documentation) * iasl (for targets with ACPI support) * gdb (for better debugging facilities on some targets) * ncurses (for 'make menuconfig') * flex and bison (for regenerating parsers) Building coreboot ----------------- Please consult http://www.coreboot.org/Build_HOWTO for details. Testing coreboot Without Modifying Your Hardware ------------------------------------------------ If you want to test coreboot without any risks before you really decide to use it on your hardware, you can use the QEMU system emulator to run coreboot virtually in QEMU. Please see http://www.coreboot.org/QEMU for details. Website and Mailing List ------------------------ Further details on the project, a FAQ, many HOWTOs, news, development guidelines and more can be found on the coreboot website: http://www.coreboot.org You can contact us directly on the coreboot mailing list: http://www.coreboot.org/Mailinglist Copyright and License --------------------- The copyright on coreboot is owned by quite a large number of individual developers and companies. Please check the individual source files for details. coreboot is licensed under the terms of the GNU General Public License (GPL). Some files are licensed under the "GPL (version 2, or any later version)", and some files are licensed under the "GPL, version 2". For some parts, which were derived from other projects, other (GPL-compatible) licenses may apply. Please check the individual source files for details. This makes the resulting coreboot images licensed under the GPL, version 2.