PCI/ASPM: Restore parent state to parent, child state to child

There's a typo that makes parent device uses child LNKCTL value and vice
versa. This causes Micron NVMe to trigger a reboot upon system

PCI/ASPM: Restore parent state to parent, child state to child

There's a typo that makes parent device uses child LNKCTL value and vice
versa. This causes Micron NVMe to trigger a reboot upon system resume.

Correct the typo to fix the issue.

Fixes: 64dbb2d70744 ("PCI/ASPM: Disable L1 before configuring L1 Substates")
Link: https://lore.kernel.org/r/20240506051602.1990743-1-kai.heng.feng@canonical.com
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
[bhelgaas: update subject]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

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PCI/ASPM: Clean up ASPM disable/enable mask calculation

With only one set of defines remaining, state can be almost used as-is to
set ->aspm_disable/default. Only CLKPM and L1 PM substates need spec

PCI/ASPM: Clean up ASPM disable/enable mask calculation

With only one set of defines remaining, state can be almost used as-is to
set ->aspm_disable/default. Only CLKPM and L1 PM substates need special
handling.

Remove unnecessary if conditions that can use the state variable bits
directly. Move ASPM mask calculation into pci_calc_aspm_enable_mask() and
pci_calc_aspm_disable_mask() helpers which makes it easier to alter state
variable directly.

Link: https://lore.kernel.org/r/20240322123952.6384-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/ASPM: Consolidate link state defines

The linux/pci.h and aspm.c files define their own sets of link state
related defines which are almost the same.

Consolidate the use of defines into those de

PCI/ASPM: Consolidate link state defines

The linux/pci.h and aspm.c files define their own sets of link state
related defines which are almost the same.

Consolidate the use of defines into those defined by linux/pci.h and expand
PCIE_LINK_STATE_L0S to match earlier ASPM_STATE_L0S that includes both
upstream and downstream bits. Rename also the defines that are internal to
aspm.c to start with PCIE_LINK_STATE for consistency.

While the PCIE_LINK_STATE_L0S BIT(0) -> (BIT(0) | BIT(1)) transformation is
not 1:1, in practice aspm.c already used ASPM_STATE_L0S that has both bits
enabled except during mapping.

While at it, place the PCIE_LINK_STATE_CLKPM define last to have more
logical grouping.

Use static_assert() to ensure PCIE_LINK_STATE_L0S is strictly equal to the
combination of PCIE_LINK_STATE_L0S_UP/DW.

Link: https://lore.kernel.org/r/20240322123952.6384-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/ASPM: Update save_state when configuration changes

Many PCIe device drivers save the configuration state of their device
during probe and restore it when their .slot_reset() hook is called durin

PCI/ASPM: Update save_state when configuration changes

Many PCIe device drivers save the configuration state of their device
during probe and restore it when their .slot_reset() hook is called during
PCIe error recovery.

If the ASPM configuration is changed after the driver's probe is called and
before an error event occurs, .slot_reset() restores the ASPM configuration
to what it was at the time of probe, not to what it was just before the
occurrence of the error event. This leads to a mismatch in ASPM
configuration between the device and its upstream device.

Update the saved configuration of the device when the ASPM configuration
changes.

Link: https://lore.kernel.org/r/20240222174436.3565146-1-vidyas@nvidia.com
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
[bhelgaas: commit log, rebase to pci/aspm, rename to
pci_update_aspm_saved_state() since it updates only LNKCTL, update only
ASPMC and CLKREQ_EN in LNKCTL]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: David E. Box <david.e.box@linux.intel.com>

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PCI/ASPM: Disable L1 before configuring L1 Substates

Per PCIe r6.1, sec 5.5.4, L1 must be disabled while setting ASPM L1 PM
Substates enable bits. Previously this was enforced by clearing
PCI_EXP_L

PCI/ASPM: Disable L1 before configuring L1 Substates

Per PCIe r6.1, sec 5.5.4, L1 must be disabled while setting ASPM L1 PM
Substates enable bits. Previously this was enforced by clearing
PCI_EXP_LNKCTL_ASPMC before calling pci_restore_aspm_l1ss_state().

Move the L1 (and L0s, although that doesn't seem required) disable into
pci_restore_aspm_l1ss_state() itself so it's closer to the code that
depends on it.

Link: https://lore.kernel.org/r/20240223213733.GA115410@bhelgaas
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/ASPM: Save L1 PM Substates Capability for suspend/resume

4ff116d0d5fd ("PCI/ASPM: Save L1 PM Substates Capability for
suspend/resume") restored the L1 PM Substates Capability after resume,
which

PCI/ASPM: Save L1 PM Substates Capability for suspend/resume

4ff116d0d5fd ("PCI/ASPM: Save L1 PM Substates Capability for
suspend/resume") restored the L1 PM Substates Capability after resume,
which reduced power consumption by making the ASPM L1.x states work after
resume.

a7152be79b62 ("Revert "PCI/ASPM: Save L1 PM Substates Capability for
suspend/resume"") reverted 4ff116d0d5fd because resume failed on some
systems, so power consumption after resume increased again.

a7152be79b62 mentioned that we restore L1 PM substate configuration even
though ASPM L1 may already be enabled. This is due the fact that the
pci_restore_aspm_l1ss_state() was called before pci_restore_pcie_state().

Save and restore the L1 PM Substates Capability, following PCIe r6.1, sec
5.5.4 more closely by:

1) Do not restore ASPM configuration in pci_restore_pcie_state() but
do that after PCIe capability is restored in pci_restore_aspm_state()
following PCIe r6.1, sec 5.5.4.

2) If BIOS reenables L1SS, particularly L1.2, we need to clear the
enables in the right order, downstream before upstream. Defer
restoring the L1SS config until we are at the downstream component.
Then update the config for both ends of the link in the prescribed
order.

3) Program ASPM L1 PM substate configuration before L1 enables.

4) Program ASPM L1 PM substate enables last, after rest of the fields
in the capability are programmed.

[bhelgaas: commit log, squash L1SS-related patches, do both LNKCTL restores
in pci_restore_pcie_state()]

Link: https://lore.kernel.org/r/20240128233212.1139663-3-david.e.box@linux.intel.com
Link: https://lore.kernel.org/r/20240128233212.1139663-4-david.e.box@linux.intel.com
Link: https://lore.kernel.org/r/20240223205851.114931-5-helgaas@kernel.org
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217321
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216782
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216877
Co-developed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Co-developed-by: David E. Box <david.e.box@linux.intel.com>
Reported-by: Koba Ko <koba.ko@canonical.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Tasev Nikola <tasev.stefanoska@skynet.be> # Asus UX305FA
Cc: Mark Enriquez <enriquezmark36@gmail.com>
Cc: Thomas Witt <kernel@witt.link>
Cc: Werner Sembach <wse@tuxedocomputers.com>
Cc: Vidya Sagar <vidyas@nvidia.com>

show more ...

PCI/ASPM: Move pci_save_ltr_state() to aspm.c

Even when CONFIG_PCIEASPM is not set, we save and restore the LTR
Capability so that if ASPM L1.2 and LTR were configured by the platform,
ASPM L1.2 wil

PCI/ASPM: Move pci_save_ltr_state() to aspm.c

Even when CONFIG_PCIEASPM is not set, we save and restore the LTR
Capability so that if ASPM L1.2 and LTR were configured by the platform,
ASPM L1.2 will still work after suspend/resume, when that platform
configuration may be lost. See dbbfadf23190 ("PCI/ASPM: Save LTR Capability
for suspend/resume").

Since ASPM L1.2 depends on the LTR Capability, move the save/restore code
to the part of aspm.c that is always compiled regardless of
CONFIG_PCIEASPM. No functional change intended.

Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20240128233212.1139663-5-david.e.box@linux.intel.com
[bhelgaas: commit log, reorder to make this a pure move]
Link: https://lore.kernel.org/r/20240223205851.114931-4-helgaas@kernel.org
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/ASPM: Always build aspm.c

Some ASPM-related tasks, such as save and restore of LTR and L1SS
capabilities, still need to be performed when CONFIG_PCIEASPM is not
enabled. To prepare for these cha

PCI/ASPM: Always build aspm.c

Some ASPM-related tasks, such as save and restore of LTR and L1SS
capabilities, still need to be performed when CONFIG_PCIEASPM is not
enabled. To prepare for these changes, wrap the current code in aspm.c
with an #ifdef and always build the file.

Link: https://lore.kernel.org/r/20240128233212.1139663-2-david.e.box@linux.intel.com
[bhelgaas: split build change from function moves]
Link: https://lore.kernel.org/r/20240223205851.114931-3-helgaas@kernel.org
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

show more ...

PCI/ASPM: Move pci_configure_ltr() to aspm.c

The Latency Tolerance Reporting (LTR) mechanism supports the ASPM L1.2
state and is only configured when CONFIG_PCIEASPM is set.

Move pci_configure_ltr(

PCI/ASPM: Move pci_configure_ltr() to aspm.c

The Latency Tolerance Reporting (LTR) mechanism supports the ASPM L1.2
state and is only configured when CONFIG_PCIEASPM is set.

Move pci_configure_ltr() and pci_bridge_reconfigure_ltr() into aspm.c since
they only build when CONFIG_PCIEASPM is set. No functional change
intended.

Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20240128233212.1139663-2-david.e.box@linux.intel.com
[bhelgaas: commit log, split build change from function moves]
Link: https://lore.kernel.org/r/20240223205851.114931-2-helgaas@kernel.org
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/ASPM: Fix deadlock when enabling ASPM

A last minute revert in 6.7-final introduced a potential deadlock when
enabling ASPM during probe of Qualcomm PCIe controllers as reported by
lockdep:

==

PCI/ASPM: Fix deadlock when enabling ASPM

A last minute revert in 6.7-final introduced a potential deadlock when
enabling ASPM during probe of Qualcomm PCIe controllers as reported by
lockdep:

============================================
WARNING: possible recursive locking detected
6.7.0 #40 Not tainted
--------------------------------------------
kworker/u16:5/90 is trying to acquire lock:
ffffacfa78ced000 (pci_bus_sem){++++}-{3:3}, at: pcie_aspm_pm_state_change+0x58/0xdc

but task is already holding lock:
ffffacfa78ced000 (pci_bus_sem){++++}-{3:3}, at: pci_walk_bus+0x34/0xbc

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(pci_bus_sem);
lock(pci_bus_sem);

*** DEADLOCK ***

Call trace:
print_deadlock_bug+0x25c/0x348
__lock_acquire+0x10a4/0x2064
lock_acquire+0x1e8/0x318
down_read+0x60/0x184
pcie_aspm_pm_state_change+0x58/0xdc
pci_set_full_power_state+0xa8/0x114
pci_set_power_state+0xc4/0x120
qcom_pcie_enable_aspm+0x1c/0x3c [pcie_qcom]
pci_walk_bus+0x64/0xbc
qcom_pcie_host_post_init_2_7_0+0x28/0x34 [pcie_qcom]

The deadlock can easily be reproduced on machines like the Lenovo ThinkPad
X13s by adding a delay to increase the race window during asynchronous
probe where another thread can take a write lock.

Add a new pci_set_power_state_locked() and associated helper functions that
can be called with the PCI bus semaphore held to avoid taking the read lock
twice.

Link: https://lore.kernel.org/r/ZZu0qx2cmn7IwTyQ@hovoldconsulting.com
Link: https://lore.kernel.org/r/20240130100243.11011-1-johan+linaro@kernel.org
Fixes: f93e71aea6c6 ("Revert "PCI/ASPM: Remove pcie_aspm_pm_state_change()"")
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: <stable@vger.kernel.org> # 6.7

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Revert "PCI/ASPM: Remove pcie_aspm_pm_state_change()"

This reverts commit 08d0cc5f34265d1a1e3031f319f594bd1970976c.

Michael reported that when attempting to resume from suspend to RAM on ASUS
mini

Revert "PCI/ASPM: Remove pcie_aspm_pm_state_change()"

This reverts commit 08d0cc5f34265d1a1e3031f319f594bd1970976c.

Michael reported that when attempting to resume from suspend to RAM on ASUS
mini PC PN51-BB757MDE1 (DMI model: MINIPC PN51-E1), 08d0cc5f3426
("PCI/ASPM: Remove pcie_aspm_pm_state_change()") caused a 12-second delay
with no output, followed by a reboot.

Workarounds include:

- Reverting 08d0cc5f3426 ("PCI/ASPM: Remove pcie_aspm_pm_state_change()")
- Booting with "pcie_aspm=off"
- Booting with "pcie_aspm.policy=performance"
- "echo 0 | sudo tee /sys/bus/pci/devices/0000:03:00.0/link/l1_aspm"
before suspending
- Connecting a USB flash drive

Link: https://lore.kernel.org/r/20240102232550.1751655-1-helgaas@kernel.org
Fixes: 08d0cc5f3426 ("PCI/ASPM: Remove pcie_aspm_pm_state_change()")
Reported-by: Michael Schaller <michael@5challer.de>
Link: https://lore.kernel.org/r/76c61361-b8b4-435f-a9f1-32b716763d62@5challer.de
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: <stable@vger.kernel.org>

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PCI: Move pci_clear_and_set_dword() helper to PCI header

The clear and set pattern is commonly used for accessing PCI config,
move the helper pci_clear_and_set_dword() from aspm.c into PCI header.
I

PCI: Move pci_clear_and_set_dword() helper to PCI header

The clear and set pattern is commonly used for accessing PCI config,
move the helper pci_clear_and_set_dword() from aspm.c into PCI header.
In addition, rename to pci_clear_and_set_config_dword() to retain the
"config" information and match the other accessors.

No functional change intended.

Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Link: https://lore.kernel.org/r/20231208025652.87192-4-xueshuai@linux.alibaba.com
Signed-off-by: Will Deacon <will@kernel.org>

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PCI/ASPM: Add pci_disable_link_state_locked() lockdep assert

Add a lockdep assert to pci_disable_link_state_locked() which should only
be called with a pci_bus_sem read lock held.

Link: https://lor

PCI/ASPM: Add pci_disable_link_state_locked() lockdep assert

Add a lockdep assert to pci_disable_link_state_locked() which should only
be called with a pci_bus_sem read lock held.

Link: https://lore.kernel.org/r/20231128081512.19387-7-johan+linaro@kernel.org
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
[bhelgaas: include function name in subject, commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

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PCI/ASPM: Clean up __pci_disable_link_state() 'sem' parameter

Replace the current 'sem' parameter to the __pci_disable_link_state()
helper with a more descriptive 'locked' parameter, which indicates

PCI/ASPM: Clean up __pci_disable_link_state() 'sem' parameter

Replace the current 'sem' parameter to the __pci_disable_link_state()
helper with a more descriptive 'locked' parameter, which indicates whether
a pci_bus_sem read lock is already held.

Link: https://lore.kernel.org/r/20231128081512.19387-6-johan+linaro@kernel.org
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
[bhelgaas: include function name in subject, commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

show more ...

PCI/ASPM: Add pci_enable_link_state_locked()

Add pci_enable_link_state_locked() for enabling link states that can be
used in contexts where a pci_bus_sem read lock is already held (e.g. from
pci_wal

PCI/ASPM: Add pci_enable_link_state_locked()

Add pci_enable_link_state_locked() for enabling link states that can be
used in contexts where a pci_bus_sem read lock is already held (e.g. from
pci_walk_bus()).

This helper will be used to fix a couple of potential deadlocks where
the current helper is called with the lock already held, hence the CC
stable tag.

Fixes: f492edb40b54 ("PCI: vmd: Add quirk to configure PCIe ASPM and LTR")
Link: https://lore.kernel.org/r/20231128081512.19387-2-johan+linaro@kernel.org
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
[bhelgaas: include helper name in subject, commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: <stable@vger.kernel.org> # 6.3
Cc: Michael Bottini <michael.a.bottini@linux.intel.com>
Cc: David E. Box <david.e.box@linux.intel.com>

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PCI: Simplify pcie_capability_clear_and_set_word() to ..._clear_word()

When using pcie_capability_clear_and_set_word() but not actually *setting*
anything, use pcie_capability_clear_word() instead.

PCI: Simplify pcie_capability_clear_and_set_word() to ..._clear_word()

When using pcie_capability_clear_and_set_word() but not actually *setting*
anything, use pcie_capability_clear_word() instead.

Link: https://lore.kernel.org/r/20231026121924.2164-1-ilpo.jarvinen@linux.intel.com
Link: https://lore.kernel.org/r/20231026121924.2164-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
[bhelgaas: squash]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/ASPM: Fix L1 substate handling in aspm_attr_store_common()

aspm_attr_store_common(), which handles sysfs control of ASPM, has the same
problem as fb097dcd5a28 ("PCI/ASPM: Disable only ASPM_STATE

PCI/ASPM: Fix L1 substate handling in aspm_attr_store_common()

aspm_attr_store_common(), which handles sysfs control of ASPM, has the same
problem as fb097dcd5a28 ("PCI/ASPM: Disable only ASPM_STATE_L1 when driver
disables L1"): disabling L1 adds only ASPM_L1 (but not any of the L1.x
substates) to the "aspm_disable" mask.

Enabling one substate, e.g., L1.1, via sysfs removes ASPM_L1 from the
disable mask. Since disabling L1 via sysfs doesn't add any of the
substates to the disable mask, enabling L1.1 actually enables *all* the
substates.

In this scenario:

- Write 0 to "l1_aspm" to disable L1
- Write 1 to "l1_1_aspm" to enable L1.1

the intention is to disable L1 and all L1.x substates, then enable just
L1.1, but in fact, *all* L1.x substates are enabled.

Fix this by explicitly disabling all the L1.x substates when disabling L1.

Fixes: 72ea91afbfb0 ("PCI/ASPM: Add sysfs attributes for controlling ASPM link states")
Link: https://lore.kernel.org/r/6ba7dd79-9cfe-4ed0-a002-d99cb842f361@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org

show more ...

Revert "PCI/ASPM: Disable only ASPM_STATE_L1 when driver, disables L1"

This reverts commit fb097dcd5a28c0a2325632405c76a66777a6bed9.

After fb097dcd5a28 ("PCI/ASPM: Disable only ASPM_STATE_L1 when d

Revert "PCI/ASPM: Disable only ASPM_STATE_L1 when driver, disables L1"

This reverts commit fb097dcd5a28c0a2325632405c76a66777a6bed9.

After fb097dcd5a28 ("PCI/ASPM: Disable only ASPM_STATE_L1 when driver
disables L1"), disabling L1 via pci_disable_link_state(PCIE_LINK_STATE_L1),
then enabling one substate, e.g., L1.1, via sysfs actually enables *all*
the substates.

For example, r8169 disables L1 because of hardware issues on a number of
systems, which implicitly disables the L1.1 and L1.2 substates.

On some systems, L1 and L1.1 work fine, but L1.2 causes missed rx packets.
Enabling L1.1 via the sysfs "aspm_l1_1" attribute unexpectedly enables L1.2
as well as L1.1.

After fb097dcd5a28, pci_disable_link_state(PCIE_LINK_STATE_L1) adds only
ASPM_L1 (but not any of the L1.x substates) to the "aspm_disable" mask:

--- Before fb097dcd5a28
+++ After fb097dcd5a28

# r8169 disables L1:
pci_disable_link_state(PCIE_LINK_STATE_L1)
- disable |= ASPM_L1 | ASPM_L1_1 | ASPM_L1_2 | ... # disable L1, L1.x
+ disable |= ASPM_L1 # disable L1 only

# write "1" to sysfs "aspm_l1_1" attribute:
l1_1_aspm
aspm_attr_store_common(state = ASPM_L1_1)
disable &= ~ASPM_L1_1 # enable L1.1
if (state & (ASPM_L1_1 | ...)) # if enabling any substate
disable &= ~ASPM_L1 # enable L1

# final state:
- disable = ASPM_L1_2 | ... # L1, L1.1 enabled; L1.2 disabled
+ disable = 0 # L1, L1.1, L1.2 all enabled

Enabling an L1.x substate removes the substate and L1 from the
"aspm_disable" mask. After fb097dcd5a28, the substates were not added to
the mask when disabling L1, so enabling one substate implicitly enables all
of them.

Revert fb097dcd5a28 so enabling one substate doesn't enable the others.

Link: https://lore.kernel.org/r/c75931ac-7208-4200-9ca1-821629cf5e28@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
[bhelgaas: work through example in commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org

show more ...

PCI/ASPM: Convert printk() to pr_*() and add include

Convert printk(KERN_INFO ...) to pr_info() and add the correct include
for it.

Link: https://lore.kernel.org/r/20230915155752.84640-8-ilpo.jarvi

PCI/ASPM: Convert printk() to pr_*() and add include

Convert printk(KERN_INFO ...) to pr_info() and add the correct include
for it.

Link: https://lore.kernel.org/r/20230915155752.84640-8-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/ASPM: Remove unnecessary includes

aspm.c does not use anything from delay.h nor jiffies.h so remove the
includes.

Link: https://lore.kernel.org/r/20230915155752.84640-7-ilpo.jarvinen@linux.inte

PCI/ASPM: Remove unnecessary includes

aspm.c does not use anything from delay.h nor jiffies.h so remove the
includes.

Link: https://lore.kernel.org/r/20230915155752.84640-7-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/ASPM: Use FIELD_MAX() instead of literals

Convert 0x3ff literals in encode_l12_threshold() to
FIELD_MAX(PCI_L1SS_CTL1_LTR_L12_TH_VALUE) that explains the purpose of
the literal.

Link: https://l

PCI/ASPM: Use FIELD_MAX() instead of literals

Convert 0x3ff literals in encode_l12_threshold() to
FIELD_MAX(PCI_L1SS_CTL1_LTR_L12_TH_VALUE) that explains the purpose of
the literal.

Link: https://lore.kernel.org/r/20230915155752.84640-6-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/ASPM: Use time constants

Use defined constants to convert between time units.

Link: https://lore.kernel.org/r/20230915155752.84640-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <

PCI/ASPM: Use time constants

Use defined constants to convert between time units.

Link: https://lore.kernel.org/r/20230915155752.84640-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/ASPM: Return U32_MAX instead of bit magic construct

Instead of returning a bit obscure -1U, make code's intent of returning
the maximum representable value more obvious by returning U32_MAX.

Li

PCI/ASPM: Return U32_MAX instead of bit magic construct

Instead of returning a bit obscure -1U, make code's intent of returning
the maximum representable value more obvious by returning U32_MAX.

Link: https://lore.kernel.org/r/20230915155752.84640-4-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/ASPM: Use FIELD_GET/PREP() to access PCIe capability fields

Replace open-coded variants to access PCIe capability registers fields
with FIELD_GET/PREP().

Link: https://lore.kernel.org/r/2023091

PCI/ASPM: Use FIELD_GET/PREP() to access PCIe capability fields

Replace open-coded variants to access PCIe capability registers fields
with FIELD_GET/PREP().

Link: https://lore.kernel.org/r/20230915155752.84640-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/ASPM: Use RMW accessors for changing LNKCTL

Don't assume that the device is fully under the control of ASPM and use RMW
capability accessors which do proper locking to avoid losing concurrent
up

PCI/ASPM: Use RMW accessors for changing LNKCTL

Don't assume that the device is fully under the control of ASPM and use RMW
capability accessors which do proper locking to avoid losing concurrent
updates to the register values.

If configuration fails in pcie_aspm_configure_common_clock(), the
function attempts to restore the old PCI_EXP_LNKCTL_CCC settings. Store
only the old PCI_EXP_LNKCTL_CCC bit for the relevant devices rather
than the content of the whole LNKCTL registers. It aligns better with
how pcie_lnkctl_clear_and_set() expects its parameter and makes the
code more obvious to understand.

Suggested-by: Lukas Wunner <lukas@wunner.de>
Fixes: 2a42d9dba784 ("PCIe: ASPM: Break out of endless loop waiting for PCI config bits to switch")
Fixes: 7d715a6c1ae5 ("PCI: add PCI Express ASPM support")
Link: https://lore.kernel.org/r/20230717120503.15276-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: "Rafael J. Wysocki" <rafael@kernel.org>

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