Here's another stab at this writeup. I'd appreciate any comments!
Changes from v1 to v2:
- Consumer/Producer is defined for Extended Address Space descriptors;
should be ignored for QWord/DWord/Word Address Space descriptors
- New arches may use Extended Address Space descriptors in PNP0A03 for
bridge registers, including ECAM (if the arch adds support for this)
- Add more details about MCFG and _CBA (Lv's suggestion)
- Incorporate Rafael's suggestions
---
Bjorn Helgaas (1):
PCI: Add information about describing PCI in ACPI
Documentation/PCI/00-INDEX | 2
Documentation/PCI/acpi-info.txt | 180 +++++++++++++++++++++++++++++++++++++++
2 files changed, 182 insertions(+)
create mode 100644 Documentation/PCI/acpi-info.txt
From: Fu Wei <fu.wei(a)linaro.org>
This patchset:
(1)Preparation for adding GTDT support in arm_arch_timer:
1. Move some enums and marcos to header file;
2. Add a new enum for spi type;
3. Improve printk relevant code;
4. Rename some enums and defines;
5. Rework PPI determination;
6. Rework counter frequency detection;
7. Refactor arch_timer_needs_probing, move it into DT init call
8. Introduce some new structs and refactor the MMIO timer init code
for reusing some common code.
(2)Introduce ACPI GTDT parser: drivers/acpi/arm64/acpi_gtdt.c
Parse all kinds of timer in GTDT table of ACPI:arch timer,
memory-mapped timer and SBSA Generic Watchdog timer.
This driver can help to simplify all the relevant timer drivers,
and separate all the ACPI GTDT knowledge from them.
(3)Simplify ACPI code for arm_arch_timer
(4)Add GTDT support for ARM memory-mapped timer.
This patchset has been tested on the following platforms with ACPI enabled:
(1)ARM Foundation v8 model
Changelog:
v19: https://lkml.org/lkml/2016/12/21/
Fix a '\n' missing in a error message in arch_timer_mem_init.
Add "request_mem_region" for ioremapping cntbase, according to
f947ee1 clocksource/drivers/arm_arch_timer: Map frame with of_io_request_and_map()
Rebase to 4.9.0-gfb779ff
v18: https://lkml.org/lkml/2016/12/8/446
Fix 8/15 patch problem of "int ret;" in arch_timer_acpi_init.
Rebase to 4.9.0-rc8-g9269898
v17: https://lkml.org/lkml/2016/11/25/140
Take out some cleanups from 4/15.
Merge 5/15 and 6/15, improve PPI determination code,
improve commit message.
Rework counter frequency detection.
Move arch_timer_needs_of_probing into DT init call.
Move Platform Timer scan loop back to timer init call to avoid allocating
and free memory.
Improve all the exported functions' comment.
v16: https://lkml.org/lkml/2016/11/16/268
Fix patchset problem about static enum ppi_nr of 01/13 in v15.
Refactor arch_timer_detect_rate.
Refactor arch_timer_needs_probing.
v15: https://lkml.org/lkml/2016/11/15/366
Re-order patches
Add arm_arch_timer refactoring patches to prepare for GTDT:
1. rename some enums and defines, and some cleanups
2. separate out arch_timer_uses_ppi init code and fix a potential bug
3. Improve some new structs, refactor the timer init code.
Since the some structs have been changed, GTDT parser for memory-mapped
timer and SBSA Generic Watchdog timer have been update.
v14: https://lkml.org/lkml/2016/9/28/573
Separate memory-mapped timer GTDT support into two patches
1. Refactor the timer init code to prepare for GTDT
2. Add GTDT support for memory-mapped timer
v13: http://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1231717.html
Improve arm_arch_timer code for memory-mapped
timer GTDT support, refactor original memory-mapped timer
dt support for reusing some common code.
v12: https://lkml.org/lkml/2016/9/13/250
Rebase to latest Linux 4.8-rc6
Delete the confusing "skipping" in the error message.
V11: https://lkml.org/lkml/2016/9/6/354
Rebase to latest Linux 4.8-rc5
Delete typedef (suggested by checkpatch.pl)
V10: https://lkml.org/lkml/2016/7/26/215
Drop the "readq" patch.
Rebase to latest Linux 4.7.
V9: https://lkml.org/lkml/2016/7/25/345
Improve pr_err message in acpi gtdt driver.
Update Commit message for 7/9
shorten the irq mapping function name
Improve GTDT driver for memory-mapped timer
v8: https://lkml.org/lkml/2016/7/19/660
Improve "pr_fmt(fmt)" definition: add "ACPI" in front of "GTDT",
and also improve printk message.
Simplify is_timer_block and is_watchdog.
Merge acpi_gtdt_desc_init and gtdt_arch_timer_init into acpi_gtdt_init();
Delete __init in include/linux/acpi.h for GTDT API
Make ARM64 select GTDT.
Delete "#include <linux/module.h>" from acpi_gtdt.c
Simplify GT block parse code.
v7: https://lkml.org/lkml/2016/7/13/769
Move the GTDT driver to drivers/acpi/arm64
Add add the ARM64-specific ACPI Support maintainers in MAINTAINERS
Merge 3 patches of GTDT parser driver.
Fix the for_each_platform_timer bug.
v6: https://lkml.org/lkml/2016/6/29/580
split the GTDT driver to 4 parts: basic, arch_timer, memory-mapped timer,
and SBSA Generic Watchdog timer
Improve driver by suggestions and example code from Daniel Lezcano
v5: https://lkml.org/lkml/2016/5/24/356
Sorting out all patches, simplify the API of GTDT driver:
GTDT driver just fills the data struct for arm_arch_timer driver.
v4: https://lists.linaro.org/pipermail/linaro-acpi/2016-March/006667.html
Delete the kvm relevant patches
Separate two patches for sorting out the code for arm_arch_timer.
Improve irq info export code to allow missing irq info in GTDT table.
v3: https://lkml.org/lkml/2016/2/1/658
Improve GTDT driver code:
(1)improve pr_* by defining pr_fmt(fmt)
(2)simplify gtdt_sbsa_gwdt_init
(3)improve gtdt_arch_timer_data_init, if table is NULL, it will try
to get GTDT table.
Move enum ppi_nr to arm_arch_timer.h, and add enum spi_nr.
Add arm_arch_timer get ppi from DT and GTDT support for kvm.
v2: https://lkml.org/lkml/2015/12/2/10
Rebase to latest kernel version(4.4-rc3).
Fix the bug about the config problem,
use CONFIG_ACPI_GTDT instead of CONFIG_ACPI in arm_arch_timer.c
v1: The first upstreaming version: https://lkml.org/lkml/2015/10/28/553
Fu Wei (15):
clocksource/drivers/arm_arch_timer: Move enums and defines to header
file
clocksource/drivers/arm_arch_timer: Add a new enum for spi type
clocksource/drivers/arm_arch_timer: Improve printk relevant code
clocksource/drivers/arm_arch_timer: rename some enums and defines.
clocksource/drivers/arm_arch_timer: rework PPI determination
clocksource/drivers/arm_arch_timer: Rework counter frequency
detection.
clocksource/drivers/arm_arch_timer: Refactor arch_timer_needs_probing
clocksource/drivers/arm_arch_timer: move arch_timer_needs_of_probing
into DT init call
clocksource/drivers/arm_arch_timer: Introduce some new structs to
prepare for GTDT
clocksource/drivers/arm_arch_timer: Refactor the timer init code to
prepare for GTDT
acpi/arm64: Add GTDT table parse driver
clocksource/drivers/arm_arch_timer: Simplify ACPI support code.
acpi/arm64: Add memory-mapped timer support in GTDT driver
clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped
timer
acpi/arm64: Add SBSA Generic Watchdog support in GTDT driver
arch/arm64/Kconfig | 1 +
drivers/acpi/arm64/Kconfig | 3 +
drivers/acpi/arm64/Makefile | 1 +
drivers/acpi/arm64/gtdt.c | 374 +++++++++++++++++++++++++++
drivers/clocksource/arm_arch_timer.c | 483 ++++++++++++++++++++---------------
drivers/watchdog/Kconfig | 1 +
include/clocksource/arm_arch_timer.h | 45 +++-
include/linux/acpi.h | 7 +
virt/kvm/arm/hyp/timer-sr.c | 6 +-
9 files changed, 712 insertions(+), 209 deletions(-)
create mode 100644 drivers/acpi/arm64/gtdt.c
--
2.9.3
From: Fu Wei <fu.wei(a)linaro.org>
This patchset:
(1)Preparation for adding GTDT support in arm_arch_timer:
1. Move some enums and marcos to header file;
2. Add a new enum for spi type;
3. Improve printk relevant code;
4. Rename some enums and defines;
5. Rework PPI determination;
6. Rework counter frequency detection;
7. Refactor arch_timer_needs_probing, move it into DT init call
8. Introduce some new structs and refactor the MMIO timer init code
for reusing some common code.
(2)Introduce ACPI GTDT parser: drivers/acpi/arm64/acpi_gtdt.c
Parse all kinds of timer in GTDT table of ACPI:arch timer,
memory-mapped timer and SBSA Generic Watchdog timer.
This driver can help to simplify all the relevant timer drivers,
and separate all the ACPI GTDT knowledge from them.
(3)Simplify ACPI code for arm_arch_timer
(4)Add GTDT support for ARM memory-mapped timer.
This patchset has been tested on the following platforms with ACPI enabled:
(1)ARM Foundation v8 model
Changelog:
v18: https://lkml.org/lkml/2016/12/8/
Fix 8/15 patch problem of "int ret;" in arch_timer_acpi_init
Rebase to 4.9.0-rc8-g9269898
v17: https://lkml.org/lkml/2016/11/25/140
Take out some cleanups from 4/15.
Merge 5/15 and 6/15, improve PPI determination code,
improve commit message.
Rework counter frequency detection.
Move arch_timer_needs_of_probing into DT init call.
Move Platform Timer scan loop back to timer init call to avoid allocating
and free memory.
Improve all the exported functions' comment.
v16: https://lkml.org/lkml/2016/11/16/268
Fix patchset problem about static enum ppi_nr of 01/13 in v15.
Refactor arch_timer_detect_rate.
Refactor arch_timer_needs_probing.
v15: https://lkml.org/lkml/2016/11/15/366
Re-order patches
Add arm_arch_timer refactoring patches to prepare for GTDT:
1. rename some enums and defines, and some cleanups
2. separate out arch_timer_uses_ppi init code and fix a potential bug
3. Improve some new structs, refactor the timer init code.
Since the some structs have been changed, GTDT parser for memory-mapped
timer and SBSA Generic Watchdog timer have been update.
v14: https://lkml.org/lkml/2016/9/28/573
Separate memory-mapped timer GTDT support into two patches
1. Refactor the timer init code to prepare for GTDT
2. Add GTDT support for memory-mapped timer
v13: http://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1231717.html
Improve arm_arch_timer code for memory-mapped
timer GTDT support, refactor original memory-mapped timer
dt support for reusing some common code.
v12: https://lkml.org/lkml/2016/9/13/250
Rebase to latest Linux 4.8-rc6
Delete the confusing "skipping" in the error message.
V11: https://lkml.org/lkml/2016/9/6/354
Rebase to latest Linux 4.8-rc5
Delete typedef (suggested by checkpatch.pl)
V10: https://lkml.org/lkml/2016/7/26/215
Drop the "readq" patch.
Rebase to latest Linux 4.7.
V9: https://lkml.org/lkml/2016/7/25/345
Improve pr_err message in acpi gtdt driver.
Update Commit message for 7/9
shorten the irq mapping function name
Improve GTDT driver for memory-mapped timer
v8: https://lkml.org/lkml/2016/7/19/660
Improve "pr_fmt(fmt)" definition: add "ACPI" in front of "GTDT",
and also improve printk message.
Simplify is_timer_block and is_watchdog.
Merge acpi_gtdt_desc_init and gtdt_arch_timer_init into acpi_gtdt_init();
Delete __init in include/linux/acpi.h for GTDT API
Make ARM64 select GTDT.
Delete "#include <linux/module.h>" from acpi_gtdt.c
Simplify GT block parse code.
v7: https://lkml.org/lkml/2016/7/13/769
Move the GTDT driver to drivers/acpi/arm64
Add add the ARM64-specific ACPI Support maintainers in MAINTAINERS
Merge 3 patches of GTDT parser driver.
Fix the for_each_platform_timer bug.
v6: https://lkml.org/lkml/2016/6/29/580
split the GTDT driver to 4 parts: basic, arch_timer, memory-mapped timer,
and SBSA Generic Watchdog timer
Improve driver by suggestions and example code from Daniel Lezcano
v5: https://lkml.org/lkml/2016/5/24/356
Sorting out all patches, simplify the API of GTDT driver:
GTDT driver just fills the data struct for arm_arch_timer driver.
v4: https://lists.linaro.org/pipermail/linaro-acpi/2016-March/006667.html
Delete the kvm relevant patches
Separate two patches for sorting out the code for arm_arch_timer.
Improve irq info export code to allow missing irq info in GTDT table.
v3: https://lkml.org/lkml/2016/2/1/658
Improve GTDT driver code:
(1)improve pr_* by defining pr_fmt(fmt)
(2)simplify gtdt_sbsa_gwdt_init
(3)improve gtdt_arch_timer_data_init, if table is NULL, it will try
to get GTDT table.
Move enum ppi_nr to arm_arch_timer.h, and add enum spi_nr.
Add arm_arch_timer get ppi from DT and GTDT support for kvm.
v2: https://lkml.org/lkml/2015/12/2/10
Rebase to latest kernel version(4.4-rc3).
Fix the bug about the config problem,
use CONFIG_ACPI_GTDT instead of CONFIG_ACPI in arm_arch_timer.c
v1: The first upstreaming version: https://lkml.org/lkml/2015/10/28/553
Fu Wei (15):
clocksource/drivers/arm_arch_timer: Move enums and defines to header
file
clocksource/drivers/arm_arch_timer: Add a new enum for spi type
clocksource/drivers/arm_arch_timer: Improve printk relevant code
clocksource/drivers/arm_arch_timer: rename some enums and defines.
clocksource/drivers/arm_arch_timer: rework PPI determination
clocksource/drivers/arm_arch_timer: Rework counter frequency
detection.
clocksource/drivers/arm_arch_timer: Refactor arch_timer_needs_probing
clocksource/drivers/arm_arch_timer: move arch_timer_needs_of_probing
into DT init call
clocksource/drivers/arm_arch_timer: Introduce some new structs to
prepare for GTDT
clocksource/drivers/arm_arch_timer: Refactor the timer init code to
prepare for GTDT
acpi/arm64: Add GTDT table parse driver
clocksource/drivers/arm_arch_timer: Simplify ACPI support code.
acpi/arm64: Add memory-mapped timer support in GTDT driver
clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped
timer
acpi/arm64: Add SBSA Generic Watchdog support in GTDT driver
arch/arm64/Kconfig | 1 +
drivers/acpi/arm64/Kconfig | 3 +
drivers/acpi/arm64/Makefile | 1 +
drivers/acpi/arm64/gtdt.c | 374 +++++++++++++++++++++++++++
drivers/clocksource/arm_arch_timer.c | 478 ++++++++++++++++++++---------------
drivers/watchdog/Kconfig | 1 +
include/clocksource/arm_arch_timer.h | 45 +++-
include/linux/acpi.h | 7 +
virt/kvm/arm/hyp/timer-sr.c | 6 +-
9 files changed, 708 insertions(+), 208 deletions(-)
create mode 100644 drivers/acpi/arm64/gtdt.c
--
2.9.3
FWTS 16.12.00 is released.
It is available from:
Tar: http://fwts.ubuntu.com/release/fwts-V16.12.00.tar.gz
PPA:
https://launchpad.net/~firmware-testing-team/+archive/ubuntu/ppa-fwts-stable
Release notes:
https://wiki.ubuntu.com/FirmwareTestSuite/ReleaseNotes/16.12.00
= New Features =
* ACPICA: Update to version 20161117
* klog.json: Add a few more kernel errors to the database
* opal: pci_info: Add OPAL PCI Info validation
* opal: mem_info: Add OPAL MEM Info validation
* opal: cpu_info: Add OPAL CPU Info validation
* securebootcert: add variable AuditMode checking
* securebootcert: add variable DeployedMode checking
= Fixed Bugs =
* acpica: s390x needs to be built as a 64 bit architecture
* klog.json: Update the klog database with more kernel patterns
* devicetree: dt_sysinfo: Add OPAL firmware version checks
* olog: olog.json: Update OPAL skiboot errors to check on olog scan
* fwts:dmicheck: replace memcpy with fwts_memcpy_unaligned
= Detail Changelog =
To check /usr/share/doc/fwts/changelog.Debian.gz or
fwts_16.12.00-0ubuntu1.debian.tar.gz from
https://launchpad.net/ubuntu/+source/fwts
These patches were part of https://lkml.org/lkml/2016/9/9/666 series,
however, only core part (first two patches) was approved. ThunderX quirk
example had some comments which are address in this series (resetting version
numbering).
Add ACPI PCI host controler support for ThunderX SoCs pass1.x & pass2.x using
ACPI quirk mechanism [1]. Patches rework ThunderX ECAM and PEM driver to work
with ACPI & DT boot method.
Patch set can be found here:
git@github.com:semihalf-nowicki-tomasz/linux.git (pci-quirks-thunderx-v1)
It is based on branch pci/ecam-v6 which can be found here:
[1] https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git (pci/ecam-v6)
Tomasz Nowicki (2):
PCI: thunder: Enable ACPI PCI controller for ThunderX pass2.x silicon
version
PCI: thunder: Enable ACPI PCI controller for ThunderX pass1.x silicon
version
drivers/acpi/pci_mcfg.c | 35 ++++++++++++
drivers/pci/host/pci-thunder-ecam.c | 2 +-
drivers/pci/host/pci-thunder-pem.c | 107 +++++++++++++++++++++++++++++++-----
include/linux/pci-ecam.h | 7 +++
4 files changed, 136 insertions(+), 15 deletions(-)
--
2.7.4
Hi ,
On 25 November 2016 at 22:32, kbuild test robot <lkp(a)intel.com> wrote:
> Hi Fu,
>
> [auto build test ERROR on pm/linux-next]
> [also build test ERROR on v4.9-rc6]
> [cannot apply to tip/timers/core next-20161125]
> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
>
> url: https://github.com/0day-ci/linux/commits/fu-wei-linaro-org/acpi-clocksource…
> base: https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
> config: arm64-defconfig (attached as .config)
> compiler: aarch64-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
> reproduce:
> wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/m… -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # save the attached .config to linux build tree
> make.cross ARCH=arm64
>
> Note: the linux-review/fu-wei-linaro-org/acpi-clocksource-add-GTDT-driver-and-GTDT-support-in-arm_arch_timer/20161125-171111 HEAD 498f1f2503da21841b0e7679ddbdb86a40451bdb builds fine.
> It only hurts bisectibility.
>
> All errors (new ones prefixed by >>):
>
> drivers/clocksource/arm_arch_timer.c: In function 'arch_timer_acpi_init':
Sorry, again,
a "+ int ret;" should be move from [12/15] to here, I have fix the
problem in my repo, it would happen in next patchset
https://git.linaro.org/people/fu.wei/linux.git/log/?h=topic-gtdt-wakeup-tim…
>>> drivers/clocksource/arm_arch_timer.c:1071:2: error: 'ret' undeclared (first use in this function)
> ret = arch_timer_register();
> ^~~
> drivers/clocksource/arm_arch_timer.c:1071:2: note: each undeclared identifier is reported only once for each function it appears in
>
> vim +/ret +1071 drivers/clocksource/arm_arch_timer.c
>
> 1065 return -EINVAL;
> 1066 }
> 1067
> 1068 /* Always-on capability */
> 1069 arch_timer_c3stop = !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON);
> 1070
>> 1071 ret = arch_timer_register();
> 1072 if (ret)
> 1073 return ret;
> 1074
>
> ---
> 0-DAY kernel test infrastructure Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all Intel Corporation
--
Best regards,
Fu Wei
Software Engineer
Red Hat
Hi all,
We've been working through the details of getting ACPI to work on
arm64, and there have been lots of questions about what this means for
PCI. I've outlined this for several people individually, but I'm
going to send this separately, apart from a specific patch series, to
make sure we're all on the same page. Please correct my errors and
misunderstandings.
Bjorn
The basic requirement is that the ACPI namespace should describe
*everything* that consumes address space unless there's another
standard way for the OS to find it [1, 2]. For example, windows that
are forwarded to PCI by a PCI host bridge should be described via ACPI
devices, since the OS can't locate the host bridge by itself. PCI
devices *below* the host bridge do not need to be described via ACPI,
because the resources they consume are inside the host bridge windows,
and the OS can discover them via the standard PCI enumeration
mechanism (using config accesses to read and size the BARs).
This ACPI resource description is done via _CRS methods of devices in
the ACPI namespace [2]. _CRS methods are like generalized PCI BARs:
the OS can read _CRS and figure out what resource is being consumed
even if it doesn't have a driver for the device [3]. That's important
because it means an old OS can work correctly even on a system with
new devices unknown to the OS. The new devices won't do anything, but
the OS can at least make sure no resources conflict with them.
Static tables like MCFG, HPET, ECDT, etc., are *not* mechanisms for
reserving address space! The static tables are for things the OS
needs to know early in boot, before it can parse the ACPI namespace.
If a new table is defined, an old OS needs to operate correctly even
though it ignores the table. _CRS allows that because it is generic
and understood by the old OS; a static table does not.
If the OS is expected to manage an ACPI device, that device will have
a specific _HID/_CID that tells the OS what driver to bind to it, and
the _CRS tells the OS and the driver where the device's registers are.
PNP0C02 "motherboard" devices are basically a catch-all. There's no
programming model for them other than "don't use these resources for
anything else." So any address space that is (1) not claimed by some
other ACPI device and (2) should not be assigned by the OS to
something else, should be claimed by a PNP0C02 _CRS method.
PCI host bridges are PNP0A03 or PNP0A08 devices. Their _CRS should
describe all the address space they consume. In principle, this would
be all the windows they forward down to the PCI bus, as well as the
bridge registers themselves. The bridge registers include things like
secondary/subordinate bus registers that determine the bus range below
the bridge, window registers that describe the apertures, etc. These
are all device-specific, non-architected things, so the only way a
PNP0A03/PNP0A08 driver can manage them is via _PRS/_CRS/_SRS, which
contain the device-specific details. These bridge registers also
include ECAM space, since it is consumed by the bridge.
ACPI defined a Producer/Consumer bit that was intended to distinguish
the bridge apertures from the bridge registers [4, 5]. However,
BIOSes didn't use that bit correctly, and the result is that OSes have
to assume that everything in a PCI host bridge _CRS is a window. That
leaves no way to describe the bridge registers in the PNP0A03/PNP0A08
device itself.
The workaround is to describe the bridge registers (including ECAM
space) in PNP0C02 catch-all devices [6]. With the exception of ECAM,
the bridge register space is device-specific anyway, so the generic
PNP0A03/PNP0A08 driver (pci_root.c) has no need to know about it. For
ECAM, pci_root.c learns about the space from either MCFG or the _CBA
method.
Note that the PCIe spec actually does require ECAM unless there's a
standard firmware interface for config access, e.g., the ia64 SAL
interface [7]. One reason is that we want a generic host bridge
driver (pci_root.c), and a generic driver requires a generic way to
access config space.
[1] ACPI 6.0, sec 6.1:
For any device that is on a non-enumerable type of bus (for
example, an ISA bus), OSPM enumerates the devices' identifier(s)
and the ACPI system firmware must supply an _HID object ... for
each device to enable OSPM to do that.
[2] ACPI 6.0, sec 3.7:
The OS enumerates motherboard devices simply by reading through
the ACPI Namespace looking for devices with hardware IDs.
Each device enumerated by ACPI includes ACPI-defined objects in
the ACPI Namespace that report the hardware resources the device
could occupy [_PRS], an object that reports the resources that are
currently used by the device [_CRS], and objects for configuring
those resources [_SRS]. The information is used by the Plug and
Play OS (OSPM) to configure the devices.
[3] ACPI 6.0, sec 6.2:
OSPM uses device configuration objects to configure hardware
resources for devices enumerated via ACPI. Device configuration
objects provide information about current and possible resource
requirements, the relationship between shared resources, and
methods for configuring hardware resources.
When OSPM enumerates a device, it calls _PRS to determine the
resource requirements of the device. It may also call _CRS to
find the current resource settings for the device. Using this
information, the Plug and Play system determines what resources
the device should consume and sets those resources by calling the
device’s _SRS control method.
In ACPI, devices can consume resources (for example, legacy
keyboards), provide resources (for example, a proprietary PCI
bridge), or do both. Unless otherwise specified, resources for a
device are assumed to be taken from the nearest matching resource
above the device in the device hierarchy.
[4] ACPI 6.0, sec 6.4.3.5.4:
Extended Address Space Descriptor
General Flags: Bit [0] Consumer/Producer:
1–This device consumes this resource
0–This device produces and consumes this resource
[5] ACPI 6.0, sec 19.6.43:
ResourceUsage specifies whether the Memory range is consumed by
this device (ResourceConsumer) or passed on to child devices
(ResourceProducer). If nothing is specified, then
ResourceConsumer is assumed.
[6] PCI Firmware 3.0, sec 4.1.2:
If the operating system does not natively comprehend reserving the
MMCFG region, the MMCFG region must be reserved by firmware. The
address range reported in the MCFG table or by _CBA method (see
Section 4.1.3) must be reserved by declaring a motherboard
resource. For most systems, the motherboard resource would appear
at the root of the ACPI namespace (under \_SB) in a node with a
_HID of EISAID (PNP0C02), and the resources in this case should
not be claimed in the root PCI bus’s _CRS. The resources can
optionally be returned in Int15 E820 or EFIGetMemoryMap as
reserved memory but must always be reported through ACPI as a
motherboard resource.
[7] PCI Express 3.0, sec 7.2.2:
For systems that are PC-compatible, or that do not implement a
processor-architecture-specific firmware interface standard that
allows access to the Configuration Space, the ECAM is required as
defined in this section.