aspm_attr_store_common(), which handles sysfs control of ASPM, has the same
problem as fb097dcd5a ("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: 72ea91afbf ("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
This reverts commit fb097dcd5a.
After fb097dcd5a ("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 fb097dcd5a, 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 fb097dcd5a
+++ After fb097dcd5a
# 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 fb097dcd5a, the substates were not added to
the mask when disabling L1, so enabling one substate implicitly enables all
of them.
Revert fb097dcd5a 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
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>
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>
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: 2a42d9dba7 ("PCIe: ASPM: Break out of endless loop waiting for PCI config bits to switch")
Fixes: 7d715a6c1a ("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>
- Add PCI_EXT_CAP_ID_PL_32GT define (Ben Dooks)
- Propagate firmware node by calling device_set_node() for better
modularity (Andy Shevchenko)
- Discover Data Link Layer Link Active Reporting earlier so quirks can take
advantage of it (Maciej W. Rozycki)
- Use cached Data Link Layer Link Active Reporting capability in pciehp,
powerpc/eeh, and mlx5 (Maciej W. Rozycki)
- Run quirk for devices that require OS to clear Retrain Link earlier, so
later quirks can rely on it (Maciej W. Rozycki)
- Export pcie_retrain_link() for use outside ASPM (Maciej W. Rozycki)
- Add Data Link Layer Link Active Reporting as another way for
pcie_retrain_link() to determine the link is up (Maciej W. Rozycki)
- Work around link training failures (especially on the ASMedia ASM2824
switch) by training first at 2.5GT/s and then attempting higher rates
(Maciej W. Rozycki)
* pci/enumeration:
PCI: Add failed link recovery for device reset events
PCI: Work around PCIe link training failures
PCI: Use pcie_wait_for_link_status() in pcie_wait_for_link_delay()
PCI: Add support for polling DLLLA to pcie_retrain_link()
PCI: Export pcie_retrain_link() for use outside ASPM
PCI: Export PCIe link retrain timeout
PCI: Execute quirk_enable_clear_retrain_link() earlier
PCI/ASPM: Factor out waiting for link training to complete
PCI/ASPM: Avoid unnecessary pcie_link_state use
PCI/ASPM: Use distinct local vars in pcie_retrain_link()
net/mlx5: Rely on dev->link_active_reporting
powerpc/eeh: Rely on dev->link_active_reporting
PCI: pciehp: Rely on dev->link_active_reporting
PCI: Initialize dev->link_active_reporting earlier
PCI: of: Propagate firmware node by calling device_set_node()
PCI: Add PCI_EXT_CAP_ID_PL_32GT define
# Conflicts:
# drivers/pci/pcie/aspm.c
PCIe r6.0.1, sec 7.5.3.7, recommends setting the link control parameters,
then waiting for the Link Training bit to be clear before setting the
Retrain Link bit.
This avoids a race where the LTSSM may not use the updated parameters if it
is already in the midst of link training because of other normal link
activity.
Wait for the Link Training bit to be clear before toggling the Retrain Link
bit to ensure that the LTSSM uses the updated link control parameters.
[bhelgaas: commit log, return 0 (success)/-ETIMEDOUT instead of bool for
both pcie_wait_for_retrain() and the existing pcie_retrain_link()]
Suggested-by: Lukas Wunner <lukas@wunner.de>
Fixes: 7d715a6c1a ("PCI: add PCI Express ASPM support")
Link: https://lore.kernel.org/r/20230502083923.34562-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org
"pcie_retrain_link" is not a question with a true/false answer, so "bool"
isn't quite the right return type. Return 0 for success or -ETIMEDOUT if
the retrain failed. No functional change intended.
[bhelgaas: based on Ilpo's patch below]
Link: https://lore.kernel.org/r/20230502083923.34562-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Let the caller of pcie_retrain_link() specify whether they want to use the
LT bit or the DLLLA bit of the Link Status Register to determine if link
training has completed. It is up to the caller to verify whether the use
of the DLLLA bit, the implementation of which is optional, is valid for the
device requested.
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2306110310540.64925@angie.orcam.me.uk
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Export pcie_retrain_link() for link retrain needs outside ASPM. Struct
pcie_link_state is local to ASPM and only used by pcie_retrain_link() to
get at the associated PCI device, so change the operand and adjust the lone
call site accordingly. Document the interface. No functional change at
this point.
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2306110229010.64925@angie.orcam.me.uk
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Convert LINK_RETRAIN_TIMEOUT from jiffies to milliseconds, accordingly
rename to PCIE_LINK_RETRAIN_TIMEOUT_MS, and make available via "pci.h" for
the PCI core to use. Use in pcie_wait_for_link_delay().
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2305310030280.59226@angie.orcam.me.uk
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Move code polling for the Link Training bit to clear into a function of its
own.
[bhelgaas: reorder to clean up before exposing to PCI core]
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2306111605060.64925@angie.orcam.me.uk
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Use separate local variables to hold the respective values retrieved from
the Link Control Register and the Link Status Register. Improves
readability and it makes it possible for the compiler to detect actual
uninitialised use should this code change in the future.
[bhelgaas: reorder to clean up before exposing to PCI core]
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2306110252260.64925@angie.orcam.me.uk
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Previously aspm_l1ss_init() checked if ASPM_STATE_L1SS is supported before
calling aspm_calc_l12_info(), only for that function to return if
ASPM_STATE_L1_2_MASK is not supported. Simplify the logic by directly
checking for ASPM_STATE_L1_2_MASK.
Link: https://lore.kernel.org/r/20230504111301.229358-6-ajayagarwal@google.com
Signed-off-by: Ajay Agarwal <ajayagarwal@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The functions aspm_calc_l1ss_info() and calc_l1ss_pwron() perform
calculations and register programming specific to L1.2 state. Rename them
to aspm_calc_l12_info() and calc_l12_pwron() respectively.
Link: https://lore.kernel.org/r/20230504111301.229358-5-ajayagarwal@google.com
Signed-off-by: Ajay Agarwal <ajayagarwal@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Previously pci_enable_link_state(PCIE_LINK_STATE_L1_1) enabled only
ASPM_STATE_L1_1 and did not enable ASPM_STATE_L1. The L1.1 state only
works when L1 is enabled, so enable ASPM_STATE_L1 in addition, and do the
same for L1.2.
The only current caller is vmd_pm_enable_quirk(), which enables *all* ASPM
states, so this should have no functional effect.
[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20230504111301.229358-4-ajayagarwal@google.com
Signed-off-by: Ajay Agarwal <ajayagarwal@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Previously pci_enable_link_state(PCIE_LINK_STATE_L1) enabled L1SS as well
as L1. Enable only ASPM_STATE_L1 when the caller enables L1.
The only current caller is vmd_pm_enable_quirk(), which enables *all* ASPM
states, so this should have no functional effect.
[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20230504111301.229358-3-ajayagarwal@google.com
Signed-off-by: Ajay Agarwal <ajayagarwal@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Previously pci_disable_link_state(PCIE_LINK_STATE_L1) disabled L1SS as well
as L1. This is unnecessary since pcie_config_aspm_link() takes care that
L1SS is not enabled if L1 is disabled.
Disable only ASPM_STATE_L1 when the caller disables L1. No functional
changes intended.
This is consistent with aspm_attr_store_common(), which disables only L1,
not L1SS, when L1 is disabled via the sysfs "l1_aspm" file.
[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20230504111301.229358-2-ajayagarwal@google.com
Signed-off-by: Ajay Agarwal <ajayagarwal@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Struct pcie_link_state->downstream is a pointer to the pci_dev of function
0. Previously we retained that pointer when removing function 0, and
subsequent ASPM policy changes dereferenced it, resulting in a
use-after-free warning from KASAN, e.g.:
# echo 1 > /sys/bus/pci/devices/0000:03:00.0/remove
# echo powersave > /sys/module/pcie_aspm/parameters/policy
BUG: KASAN: slab-use-after-free in pcie_config_aspm_link+0x42d/0x500
Call Trace:
kasan_report+0xae/0xe0
pcie_config_aspm_link+0x42d/0x500
pcie_aspm_set_policy+0x8e/0x1a0
param_attr_store+0x162/0x2c0
module_attr_store+0x3e/0x80
PCIe spec r6.0, sec 7.5.3.7, recommends that software program the same ASPM
Control value in all functions of multi-function devices.
Disable ASPM and free the pcie_link_state when any child function is
removed so we can discard the dangling pcie_link_state->downstream pointer
and maintain the same ASPM Control configuration for all functions.
[bhelgaas: commit log and comment]
Debugged-by: Zongquan Qin <qinzongquan@sangfor.com.cn>
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Fixes: b5a0a9b59c ("PCI/ASPM: Read and set up L1 substate capabilities")
Link: https://lore.kernel.org/r/20230507034057.20970-1-dinghui@sangfor.com.cn
Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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Merge tag 'pci-v6.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci
Pull PCI updates from Bjorn Helgaas:
"Enumeration:
- Rework portdrv shutdown so it disables interrupts but doesn't
disable bus mastering, which leads to hangs on Loongson LS7A
- Add mechanism to prevent Max_Read_Request_Size (MRRS) increases,
again to avoid hardware issues on Loongson LS7A (and likely other
devices based on DesignWare IP)
- Ignore devices with a firmware (DT or ACPI) node that says the
device is disabled
Resource management:
- Distribute spare resources to unconfigured hotplug bridges at
boot-time (not just when hot-adding such a bridge), which makes
hot-adding devices to docks work better. Tried this in v6.1 but had
to revert for regressions, so try again
- Fix root bus issue that dropped resources that happened to end
at 0, e.g., [bus 00]
PCI device hotplug:
- Remove device locking when marking device as disconnected so this
doesn't have to wait for concurrent driver bind/unbind to complete
- Quirk more Qualcomm bridges that don't fully implement the PCIe
Slot Status 'Command Completed' bit
Power management:
- Account for _S0W of the target bridge in acpi_pci_bridge_d3() so we
don't miss hot-add notifications for USB4 docks, Thunderbolt, etc
Reset:
- Observe delay after reset, e.g., resuming from system sleep,
regardless of whether a bridge can suspend to D3cold at runtime
- Wait for secondary bus to become ready after a bridge reset
Virtualization:
- Avoid FLR on some AMD FCH AHCI adapters where it doesn't work
- Allow independent IOMMU groups for some Wangxun NICs that prevent
peer-to-peer transactions but don't advertise an ACS Capability
Error handling:
- Configure End-to-End-CRC (ECRC) only if Linux owns the AER
Capability
- Remove redundant Device Control Error Reporting Enable in the AER
service driver since this is already done for all devices during
enumeration
ASPM:
- Add pci_enable_link_state() interface to allow drivers to enable
ASPM link state
Endpoint framework:
- Move dra7xx and tegra194 linkup processing from hard IRQ to
threaded IRQ handler
- Add a separate lock for endpoint controller list of endpoint
function drivers to prevent deadlock in callbacks
- Pass events from endpoint controller to endpoint function drivers
via callbacks instead of notifiers
Synopsys DesignWare eDMA controller driver (acked by Vinod):
- Fix CPU vs PCI address issues
- Fix source vs destination address issues
- Fix issues with interleaved transfer semantics
- Fix channel count initialization issue (issue still exists in
several other drivers)
- Clean up and improve debugfs usage so it will work on platforms
with several eDMA devices
Baikal T-1 PCIe controller driver:
- Set a 64-bit DMA mask
Freescale i.MX6 PCIe controller driver:
- Add i.MX8MM, i.MX8MQ, i.MX8MP endpoint mode DT binding and driver
support
Intel VMD host bridge driver:
- Add quirk to configure PCIe ASPM and LTR. This is normally done by
BIOS, and will be for future products
Marvell MVEBU PCIe controller driver:
- Mark this driver as broken in Kconfig since bugs prevent its daily
usage
MediaTek MT7621 PCIe controller driver:
- Delay PHY port initialization to improve boot reliability for ZBT
WE1326, ZBT WF3526-P, and some Netgear models
Qualcomm PCIe controller driver:
- Add MSM8998 DT compatible string
- Unify MSM8996 and MSM8998 clock orderings
- Add SM8350 DT binding and driver support
- Add IPQ8074 Gen3 DT binding and driver support
- Correct qcom,perst-regs in DT binding
- Add qcom_pcie_host_deinit() so the PHY is powered off and
regulators and clocks are disabled on late host-init errors
Socionext UniPhier Pro5 controller driver:
- Clean up uniphier-ep reg, clocks, resets, and their names in DT
binding
Synopsys DesignWare PCIe controller driver:
- Restrict coherent DMA mask to 32 bits for MSI, but allow controller
drivers to set 64-bit streaming DMA mask
- Add eDMA engine support in both Root Port and Endpoint controllers
Miscellaneous:
- Remove MODULE_LICENSE from boolean drivers so they don't look like
modules so modprobe can complain about them"
* tag 'pci-v6.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (86 commits)
PCI: dwc: Add Root Port and Endpoint controller eDMA engine support
PCI: bt1: Set 64-bit DMA mask
PCI: dwc: Restrict only coherent DMA mask for MSI address allocation
dmaengine: dw-edma: Prepare dw_edma_probe() for builtin callers
dmaengine: dw-edma: Depend on DW_EDMA instead of selecting it
dmaengine: dw-edma: Add mem-mapped LL-entries support
PCI: Remove MODULE_LICENSE so boolean drivers don't look like modules
PCI: hv: Drop duplicate PCI_MSI dependency
PCI/P2PDMA: Annotate RCU dereference
PCI/sysfs: Constify struct kobj_type pci_slot_ktype
PCI: hotplug: Allow marking devices as disconnected during bind/unbind
PCI: pciehp: Add Qualcomm quirk for Command Completed erratum
PCI: qcom: Add IPQ8074 Gen3 port support
dt-bindings: PCI: qcom: Add IPQ8074 Gen3 port
dt-bindings: PCI: qcom: Sort compatibles alphabetically
PCI: qcom: Fix host-init error handling
PCI: qcom: Add SM8350 support
dt-bindings: PCI: qcom: Add SM8350
dt-bindings: PCI: qcom-ep: Correct qcom,perst-regs
dt-bindings: PCI: qcom: Unify MSM8996 and MSM8998 clock order
...
This reverts commit 5e85eba6f5.
Thomas Witt reported that 5e85eba6f5 ("PCI/ASPM: Refactor L1 PM Substates
Control Register programming") broke suspend/resume on a Tuxedo
Infinitybook S 14 v5, which seems to use a Clevo L140CU Mainboard.
The main symptom is:
iwlwifi 0000:02:00.0: Unable to change power state from D3hot to D0, device inaccessible
nvme 0000:03:00.0: Unable to change power state from D3hot to D0, device inaccessible
and the machine is only partially usable after resume. It can't run dmesg
and can't do a clean reboot. This happens on every suspend/resume cycle.
Revert 5e85eba6f5 until we can figure out the root cause.
Fixes: 5e85eba6f5 ("PCI/ASPM: Refactor L1 PM Substates Control Register programming")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216877
Reported-by: Thomas Witt <kernel@witt.link>
Tested-by: Thomas Witt <kernel@witt.link>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org # v6.1+
Cc: Vidya Sagar <vidyas@nvidia.com>
This reverts commit 4ff116d0d5.
Tasev Nikola and Mark Enriquez reported that resume from suspend was broken
in v6.1-rc1. Tasev bisected to a47126ec29 ("PCI/PTM: Cache PTM
Capability offset"), but we can't figure out how that could be related.
Mark saw the same symptoms and bisected to 4ff116d0d5 ("PCI/ASPM: Save L1
PM Substates Capability for suspend/resume"), which does have a connection:
it restores L1 Substates configuration while ASPM L1 may be enabled:
pci_restore_state
pci_restore_aspm_l1ss_state
aspm_program_l1ss
pci_write_config_dword(PCI_L1SS_CTL1, ctl1) # L1SS restore
pci_restore_pcie_state
pcie_capability_write_word(PCI_EXP_LNKCTL, cap[i++]) # L1 restore
which is a problem because PCIe r6.0, sec 5.5.4, requires that:
If setting either or both of the enable bits for ASPM L1 PM
Substates, both ports must be configured as described in this
section while ASPM L1 is disabled.
Separately, Thomas Witt reported that 5e85eba6f5 ("PCI/ASPM: Refactor L1
PM Substates Control Register programming") broke suspend/resume, and it
depends on 4ff116d0d5.
Revert 4ff116d0d5 ("PCI/ASPM: Save L1 PM Substates Capability for
suspend/resume") to fix the resume issue and enable revert of 5e85eba6f5
to fix the issue Thomas reported.
Note that reverting 4ff116d0d5 means L1 Substates config may be lost on
suspend/resume. As far as we know the system will use more power but will
still *work* correctly.
Fixes: 4ff116d0d5 ("PCI/ASPM: Save L1 PM Substates Capability for suspend/resume")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216782
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216877
Reported-by: Tasev Nikola <tasev.stefanoska@skynet.be>
Reported-by: Mark Enriquez <enriquezmark36@gmail.com>
Reported-by: Thomas Witt <kernel@witt.link>
Tested-by: Mark Enriquez <enriquezmark36@gmail.com>
Tested-by: Thomas Witt <kernel@witt.link>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org # v6.1+
Cc: Vidya Sagar <vidyas@nvidia.com>
Add pci_enable_link_state() to allow devices to change the default BIOS
configured states. Clears the BIOS default settings then sets the new
states and reconfigures the link under the semaphore. Also add
PCIE_LINK_STATE_ALL macro for convenience for callers that want to enable
all link states.
Link: https://lore.kernel.org/r/20230120031522.2304439-2-david.e.box@linux.intel.com
Signed-off-by: Michael Bottini <michael.a.bottini@linux.intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
80d7d7a904 ("PCI/ASPM: Calculate LTR_L1.2_THRESHOLD from device
characteristics") replaced a fixed value (163840ns) with one computed from
T_POWER_OFF, Common_Mode_Restore_Time, etc., but it encoded the
LTR_L1.2_THRESHOLD value incorrectly.
This is especially a problem for small thresholds, e.g., 63ns fell into the
"threshold_ns < 1024" case and was encoded as 32ns:
LTR_L1.2_THRESHOLD_Scale = 1 (multiplier is 32ns)
LTR_L1.2_THRESHOLD_Value = 63 >> 5 = 1
LTR_L1.2_THRESHOLD = multiplier * value = 32ns * 1 = 32ns
Correct the algorithm to encode all times of 1023ns (0x3ff) or smaller
exactly and larger times conservatively (the encoded threshold is never
smaller than was requested). This reduces the chance of entering L1.2
when the device can't tolerate the exit latency.
Fixes: 80d7d7a904 ("PCI/ASPM: Calculate LTR_L1.2_THRESHOLD from device characteristics")
Link: https://lore.kernel.org/r/20221005025809.2247547-4-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
187f91db82 ("PCI/ASPM: Remove struct aspm_register_info.l1ss_cap")
inadvertently removed a check for existence of the L1 PM Substates (L1SS)
Capability before reading it.
If there is no L1SS Capability, this means we mistakenly read PCI_COMMAND
and PCI_STATUS (config address 0x04) and interpret that as the PCI_L1SS_CAP
register, so we may incorrectly configure L1SS.
Make sure the L1SS Capability exists before trying to read it.
Fixes: 187f91db82 ("PCI/ASPM: Remove struct aspm_register_info.l1ss_cap")
Link: https://lore.kernel.org/r/20221005025809.2247547-3-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Previously the L1 PM Substates Control Registers (CTL1 and CTL2) weren't
saved and restored during suspend/resume leading to the L1 PM Substates
configuration being lost post-resume.
Save the L1 PM Substates Control Registers so that the configuration is
retained post-resume.
[bhelgaas: drop pci_is_pcie() testing; we can rely on pci_configure_ltr()
having already done that]
Link: https://lore.kernel.org/r/20220913131822.16557-3-vidyas@nvidia.com
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
pcie_aspm_support_enabled() is used only by the acpi/pci_root.c driver,
which cannot be built as a module, so it does not need to be exported.
Unexport it.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
pcie_aspm_pm_state_change() was introduced at the inception of PCIe ASPM
code, but it can cause some issues. For instance, when ASPM config is
changed via sysfs, those changes won't persist across power state change
because pcie_aspm_pm_state_change() overwrites them.
Also, if the driver restores L1SS [1] after system resume, the restored
state will also be overwritten by pcie_aspm_pm_state_change().
Remove pcie_aspm_pm_state_change(). If there's any hardware that really
needs it to function, a quirk can be used instead.
[1] https://lore.kernel.org/linux-pci/20220201123536.12962-1-vidyas@nvidia.com/
Link: https://lore.kernel.org/r/20220509073639.2048236-1-kai.heng.feng@canonical.com
[bhelgaas: remove additional pcie_aspm_pm_state_change() call in
pci_set_low_power_state(), added by
10aa5377fc ("PCI/PM: Split pci_raw_set_power_state()") and moved by
7957d20145 ("PCI/PM: Relocate pci_set_low_power_state()")]
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
- Use pci_find_vsec_capability() instead of open-coding it (Andy
Shevchenko)
- Convert pci_dev_present() stub from macro to static inline to avoid
'unused variable' errors (Hans de Goede)
- Convert sysfs slot attributes from default_attrs to default_groups (Greg
Kroah-Hartman)
- Use DWORD accesses for LTR, L1 SS to avoid BayHub OZ711LV2 erratum (Rajat
Jain)
- Remove unnecessary initialization of static variables (Longji Guo)
* pci/enumeration:
x86/PCI: Remove initialization of static variables to false
PCI: Use DWORD accesses for LTR, L1 SS to avoid erratum
PCI/sysfs: Use default_groups in kobj_type for slot attrs
PCI: Convert pci_dev_present() stub to static inline
PCI: Use pci_find_vsec_capability() when looking for TBT devices
Some devices have an erratum such that they only support DWORD accesses to
some registers. E.g., this Bayhub O2 device ([VID:DID] = [0x1217:0x8621])
only supports DWORD accesses to LTR latency registers and L1 PM substates
control registers:
https://github.com/rajatxjain/public_shared/blob/main/OZ711LV2_appnote.pdf
The L1 PM substate control registers are DWORD sized, and hence their
access in the kernel is already DWORD sized, so we don't need to do
anything for them.
However, the LTR registers being WORD sized, are in need of a solution.
Convert the WORD sized accesses to these registers into DWORD sized
accesses while saving and restoring them.
Link: https://lore.kernel.org/r/20211222012105.3438916-1-rajatja@google.com
Signed-off-by: Rajat Jain <rajatja@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The struct aspm_latency is now used only inside pcie_aspm_check_latency().
Replace struct aspm_latency variables with u32 variables and remove struct
aspm_latency.
Link: https://lore.kernel.org/r/20211119193732.12343-5-refactormyself@gmail.com
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Previously we calculated the device's acceptable L0s and L1 exit latencies
in pcie_aspm_cap_init() and cached them in struct pcie_link_state.
These values are only used in pcie_aspm_check_latency() where they are
compared with the actual exit latencies of the link. This path is used
when removing or changing the D state of the device, so it's relatively low
frequency.
To reduce the amount of per-link data we store, remove the acceptable[]
arrays from struct pcie_link_state and calculate them directly from the
already-cached Device Capabilities register when needed.
[bhelgaas: use endpoint->devcap instead of reading it again]
Link: https://lore.kernel.org/r/20211119193732.12343-4-refactormyself@gmail.com
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Previously we calculated the upstream and downstream L0s and L1 exit
latencies of the link in pcie_aspm_cap_init() and cached them in struct
pcie_link_state.latency_*.
These values are only used in pcie_aspm_check_latency() where they are
compared with the acceptable latencies on the link. This path is used when
removing or changing the D state of the device, so it's relatively low
frequency.
To reduce the amount of per-link data we store, remove the latency_*
entries from struct pcie_link_state and calculate the latencies directly
where they are needed.
Link: https://lore.kernel.org/r/20211119193732.12343-3-refactormyself@gmail.com
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Move pci_function_0() earlier so we can use it from other functions.
Link: https://lore.kernel.org/r/20211119193732.12343-2-refactormyself@gmail.com
Signed-off-by: Bolarinwa O. Saheed <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
strtobool() is a wrapper around kstrtobool() that has been added for
backward compatibility.
There is no reason to use the old API, so use kstrtobool() directly.
Related: ef95159907 ("lib: move strtobool() to kstrtobool()")
Link: https://lore.kernel.org/r/20210915230127.2495723-3-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The sysfs_emit() and sysfs_emit_at() functions were introduced to make
it less ambiguous which function is preferred when writing to the output
buffer in a device attribute's "show" callback [1].
Convert the PCI sysfs object "show" functions from sprintf(), snprintf()
and scnprintf() to sysfs_emit() and sysfs_emit_at() accordingly, as the
latter is aware of the PAGE_SIZE buffer and correctly returns the number
of bytes written into the buffer.
No functional change intended.
[1] Documentation/filesystems/sysfs.rst
Related commit: ad025f8e46 ("PCI/sysfs: Use sysfs_emit() and
sysfs_emit_at() in "show" functions").
Link: https://lore.kernel.org/r/20210603000112.703037-2-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Previously ASPM L1 Substates control registers (CTL1 and CTL2) weren't
saved and restored during suspend/resume leading to L1 Substates
configuration being lost post-resume.
Save the L1 Substates control registers so that the configuration is
retained post-resume.
Link: https://lore.kernel.org/r/20201024190442.871-1-vidyas@nvidia.com
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Previously we computed L1.2 parameters in the enumeration path, saved them
in struct pcie_link_state.l1ss, and programmed them into the devices
whenever we enabled or disabled L1.2 on the link. But these parameters are
constant and don't need to be updated when enabling/disabling L1.2.
Compute and program the L1.2 parameters once during enumeration and remove
the struct pcie_link_state.l1ss member. No functional change intended.
[bhelgaas: rework to program L1.2 parameters during enumeration]
Link: https://lore.kernel.org/r/20201015193039.12585-13-helgaas@kernel.org
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Previously we stored the L1SS Capabilities value in the struct
aspm_register_info.
We only need this information in one place, so read it there and remove
struct aspm_register_info completely, since it's now empty. No functional
change intended.
[bhelgaas: split up, don't cache l1ss_cap in pci_dev]
Link: https://lore.kernel.org/r/20201015193039.12585-12-helgaas@kernel.org
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Bjorn Helgaas
Ilpo Järvinen
Heiner Kallweit
Maciej W. Rozycki
Ajay Agarwal
Ding Hui
Linus Torvalds
Michael Bottini
Vidya Sagar
Kai-Heng Feng
Rajat Jain
Saheed O. Bolarinwa
Krzysztof Wilczyński