The sole non-static function in err.c, pcie_do_recovery(), is only
called from:
* aer.c (if CONFIG_PCIEAER=y)
* dpc.c (if CONFIG_PCIE_DPC=y, which depends on CONFIG_PCIEAER)
* edr.c (if CONFIG_PCIE_EDR=y, which depends on CONFIG_PCIE_DPC)
Thus, err.c need not be compiled if CONFIG_PCIEAER=n.
Also, pci_uevent_ers() and pcie_clear_device_status(), which are called
from err.c, can be #ifdef'ed away unless CONFIG_PCIEAER=y.
Since x86_64_defconfig doesn't enable CONFIG_PCIEAER, this change may
slightly reduce compile time for anyone doing a test build with that
config.
Link: https://lore.kernel.org/r/98f9041151268c1c035ab64cca320ad86803f64a.1627638184.git.lukas@wunner.de
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Stuart Hayes reports that an error handled by DPC at a Root Port results
in pciehp gratuitously bringing down a subordinate hotplug port:
RP -- UP -- DP -- UP -- DP (hotplug) -- EP
pciehp brings the slot down because the Link to the Endpoint goes down.
That is caused by a Hot Reset being propagated as a result of DPC.
Per PCIe Base Spec 5.0, section 6.6.1 "Conventional Reset":
For a Switch, the following must cause a hot reset to be sent on all
Downstream Ports: [...]
* The Data Link Layer of the Upstream Port reporting DL_Down status.
In Switches that support Link speeds greater than 5.0 GT/s, the
Upstream Port must direct the LTSSM of each Downstream Port to the
Hot Reset state, but not hold the LTSSMs in that state. This permits
each Downstream Port to begin Link training immediately after its
hot reset completes. This behavior is recommended for all Switches.
* Receiving a hot reset on the Upstream Port.
Once DPC recovers, pcie_do_recovery() walks down the hierarchy and
invokes pcie_portdrv_slot_reset() to restore each port's config space.
At that point, a hotplug interrupt is signaled per PCIe Base Spec r5.0,
section 6.7.3.4 "Software Notification of Hot-Plug Events":
If the Port is enabled for edge-triggered interrupt signaling using
MSI or MSI-X, an interrupt message must be sent every time the logical
AND of the following conditions transitions from FALSE to TRUE: [...]
* The Hot-Plug Interrupt Enable bit in the Slot Control register is
set to 1b.
* At least one hot-plug event status bit in the Slot Status register
and its associated enable bit in the Slot Control register are both
set to 1b.
Prevent pciehp from gratuitously bringing down the slot by clearing the
error-induced Data Link Layer State Changed event before restoring
config space. Afterwards, check whether the link has unexpectedly
failed to retrain and synthesize a DLLSC event if so.
Allow each pcie_port_service_driver (one of them being pciehp) to define
a slot_reset callback and re-use the existing pm_iter() function to
iterate over the callbacks.
Thereby, the Endpoint driver remains bound throughout error recovery and
may restore the device to working state.
Surprise removal during error recovery is detected through a Presence
Detect Changed event. The hotplug port is expected to not signal that
event as a result of a Hot Reset.
The issue isn't DPC-specific, it also occurs when an error is handled by
AER through aer_root_reset(). So while the issue was noticed only now,
it's been around since 2006 when AER support was first introduced.
[bhelgaas: drop PCI_ERROR_RECOVERY Kconfig, split pm_iter() rename to
preparatory patch]
Link: https://lore.kernel.org/linux-pci/08c046b0-c9f2-3489-eeef-7e7aca435bb9@gmail.com/
Fixes: 6c2b374d74 ("PCI-Express AER implemetation: AER core and aerdriver")
Link: https://lore.kernel.org/r/251f4edcc04c14f873ff1c967bc686169cd07d2d.1627638184.git.lukas@wunner.de
Reported-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Tested-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org # v2.6.19+: ba952824e6: PCI/portdrv: Report reset for frozen channel
Cc: Keith Busch <kbusch@kernel.org>
Struct pci_driver contains a struct device_driver, so for PCI devices, it's
easy to convert a device_driver * to a pci_driver * with to_pci_driver().
The device_driver * is in struct device, so we don't need to also keep
track of the pci_driver * in struct pci_dev.
Replace pdev->driver with to_pci_driver(). This is a step toward removing
pci_dev->driver.
[bhelgaas: split to separate patch]
Link: https://lore.kernel.org/r/20211004125935.2300113-11-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
The condition register PCI_RCV_INTX is used in irq_mask() and irq_unmask()
callbacks. Accesses to register can occur at the same time without a lock.
Add a lock into each callback to prevent the issue.
And INTX mask and unmask fields in PCL_RCV_INTX register should only be
set/reset for each bit. Clearing by PCL_RCV_INTX_ALL_MASK should be
removed.
INTX status fields in PCL_RCV_INTX register only indicates each INTX
interrupt status, so the handler can't clear by writing 1 to the field.
The status is expected to be cleared by the interrupt origin.
The ack function has no meaning, so should remove it.
Suggested-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/1631924579-24567-1-git-send-email-hayashi.kunihiko@socionext.com
Fixes: 7e6d5cd88a ("PCI: uniphier: Add UniPhier PCIe host controller support")
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Pali Rohár <pali@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
If an error is encountered when executing a MRPC command, the firmware
will set the status register to SWITCHTEC_MRPC_STATUS_ERROR and return
the error code in the return value register.
Add handling of SWITCHTEC_MRPC_STATUS_ERROR on status register when
completing a MRPC command.
Link: https://lore.kernel.org/r/20211014141859.11444-3-kelvin.cao@microchip.com
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
A firmware hard reset may be initiated by various mechanisms including a
UART interface, TWI sideband interface from BMC, MRPC command from
userspace, etc. The switchtec management driver is unaware of these
resets.
The reset clears PCI state including the BARs and Memory Space Enable
bits, so the device no longer responds to the MMIO accesses the driver
uses to operate it.
MMIO reads to the device will fail with a PCIe error. When the root
complex handles that error, it typically fabricates ~0 data to complete
the CPU read.
Check for this sort of error by reading the device ID from MMIO space.
This ID can never be ~0, so if we see that value, it probably means the
PCIe Memory Read failed and we should return an error indication to the
application using the switchtec driver.
Link: https://lore.kernel.org/r/20211014141859.11444-2-kelvin.cao@microchip.com
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Previously, when msi_populate_sysfs() failed, we saved the error return
value as dev->msi_irq_groups, which leads to a page fault when
free_msi_irqs() calls msi_destroy_sysfs().
To prevent this, leave dev->msi_irq_groups alone when msi_populate_sysfs()
fails.
Found by the Hulk Robot when injecting a memory allocation fault in
msi_populate_sysfs():
BUG: unable to handle page fault for address: fffffffffffffff4
...
Call Trace:
msi_destroy_sysfs+0x30/0xa0
free_msi_irqs+0x11d/0x1b0
Fixes: 2f170814bd ("genirq/msi: Move MSI sysfs handling from PCI to MSI core")
Link: https://lore.kernel.org/r/20211012071556.939137-1-wanghai38@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Barry Song <song.bao.hua@hisilicon.com>
Save the struct pci_driver pointer from pdev->driver instead of repeating
it several times. No functional change.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cppcheck warns that pci_dev_str_match_path() passes pointers to signed ints
to sscanf("%x"), which expects pointers to *unsigned* ints:
invalidScanfArgType_int drivers/pci/pci.c:312 %x in format string (no. 2) requires 'unsigned int *' but the argument type is 'signed int *'.
Declare the variables as unsigned to avoid this issue.
[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20211008222732.2868493-3-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
"dom_req" is a u16 but varargs automatically promotes it to int, so there's
no point in using the %h modifier. Drop it.
See cbacb5ab0a ("docs: printk-formats: Stop encouraging use of
unnecessary %h[xudi] and %hh[xudi]") and 70eb2275ff ("checkpatch: add
warning for unnecessary use of %h[xudi] and %hh[xudi]").
Link: https://lore.kernel.org/r/20211008222732.2868493-1-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
When enabling VMD in BIOS setup (Ice Lake Processor: Whitley platform),
the host OS cannot boot successfully with the following error message:
nvme nvme0: I/O 12 QID 0 timeout, completion polled
nvme nvme0: Shutdown timeout set to 6 seconds
DMAR: DRHD: handling fault status reg 2
DMAR: [INTR-REMAP] Request device [0x00:0x00.5] fault index 0xa00 [fault reason 0x25] Blocked a compatibility format interrupt request
The request device is the VMD controller:
# lspci -s 0000:00.5 -nn
0000:00:00.5 RAID bus controller [0104]: Intel Corporation Volume
Management Device NVMe RAID Controller [8086:28c0] (rev 04)
`git bisect` points to this offending commit ee81ee84f8 ("PCI:
vmd: Disable MSI-X remapping when possible"), which disables VMD MSI
remapping. The IOMMU hardware blocks the compatibility format
interrupt request because Interrupt Remapping Enable Status (IRES) and
Extended Interrupt Mode Enable (EIME) are enabled. Please refer to
section "5.1.4 Interrupt-Remapping Hardware Operation" in Intel VT-d
spec.
To fix the issue, VMD driver still enables the interrupt remapping
irrespective of VMD_FEAT_CAN_BYPASS_MSI_REMAP if the IOMMU subsystem
enables the interrupt remapping.
Test configuration is shown as follows:
* Two VMD controllers
1. 8086:28c0 (Whitley's VMD)
2. 8086:201d (Purley's VMD: The issue does not appear in this
controller. Just make sure if any side effect occurs.)
* w/wo intremap=off
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=214219
Link: https://lore.kernel.org/r/20210901124047.1615-1-adrianhuang0701@gmail.com
Signed-off-by: Adrian Huang <ahuang12@lenovo.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Cc: Jon Derrick <jonathan.derrick@intel.com>
Cc: Nirmal Patel <nirmal.patel@linux.intel.com>
Cc: Joerg Roedel <jroedel@suse.de>
On the Qualcomm sc8180x platform the bootloader does something related
to PCI that leaves a pending "msi" interrupt, which with the current
ordering often fires before init has a chance to enable the clocks that
are necessary for the interrupt handler to access the hardware.
Move the host_init() call before the registration of the "msi" interrupt
handler to ensure the host driver has a chance to enable the clocks.
The assignment of the bridge's ops and child_ops is moved along, because
at least the TI Keystone driver overwrites these in its host_init
callback.
Link: https://lore.kernel.org/r/20210823154958.305677-1-bjorn.andersson@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Add driver for Qualcomm PCIe Endpoint controller based on the DesignWare
core with added Qualcomm-specific wrapper around the core. The driver
support is very basic such that it supports only enumeration, PCIe
read/write, and MSI. There is no ASPM and PM support for now but these will
be added later.
The driver is capable of using the PERST# and WAKE# side-band GPIOs for
operation and written on top of the DWC PCI framework.
[bhelgaas: wrap a few long lines]
Co-developed-by: Siddartha Mohanadoss <smohanad@codeaurora.org>
[mani: restructured the driver and fixed several bugs for upstream]
Link: https://lore.kernel.org/r/20210920065946.15090-3-manivannan.sadhasivam@linaro.org
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>
In certain cases we need a variant of pci_read_vpd()/pci_write_vpd() that
does not check against dev->vpd.len. Such cases are:
- Reading VPD if dev->vpd.len isn't set yet (in pci_vpd_size())
- Devices that map non-VPD information to arbitrary places in VPD address
space (example: Chelsio T3 EEPROM write-protect flag)
Therefore add pci_read_vpd_any() and pci_write_vpd_any() that check against
PCI_VPD_MAX_SIZE only.
Link: https://lore.kernel.org/r/93ecce28-a158-f02a-d134-8afcaced8efe@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Pull s390 fixes from Vasily Gorbik:
- Fix potential memory leak on a error path in eBPF
- Fix handling of zpci device on reserve
* tag 's390-5.15-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/pci: fix zpci_zdev_put() on reserve
bpf, s390: Fix potential memory leak about jit_data
Pull ACPI fix from Rafael Wysocki:
"Fix a recent ACPI-related regression in the PCI subsystem that
introduced a NULL pointer dereference possible to trigger from
user space via sysfs on some systems"
* tag 'acpi-5.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PCI: ACPI: Check parent pointer in acpi_pci_find_companion()
Pull hyperv fixes from Wei Liu:
- Replace uuid.h with types.h in a header (Andy Shevchenko)
- Avoid sleeping in atomic context in PCI driver (Long Li)
- Avoid sending IPI to self when it shouldn't (Vitaly Kuznetsov)
* tag 'hyperv-fixes-signed-20211007' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
x86/hyperv: Avoid erroneously sending IPI to 'self'
hyper-v: Replace uuid.h with types.h
PCI: hv: Fix sleep while in non-sleep context when removing child devices from the bus
If acpi_pci_find_companion() is called for a device whose parent
pointer is NULL, it will crash when attempting to get the ACPI
companion of the parent due to a NULL pointer dereference in
the ACPI_COMPANION() macro.
This was not a problem before commit 375553a932 ("PCI: Setup ACPI
fwnode early and at the same time with OF") that made pci_setup_device()
call pci_set_acpi_fwnode() and so it allowed devices with NULL parent
pointers to be passed to acpi_pci_find_companion() which is the case
in pci_iov_add_virtfn(), for instance.
Fix this issue by making acpi_pci_find_companion() check the device's
parent pointer upfront and bail out if it is NULL.
While pci_iov_add_virtfn() can be changed to set the device's parent
pointer before calling pci_setup_device() for it, checking pointers
against NULL before dereferencing them is prudent anyway and looking
for ACPI companions of virtual functions isn't really useful.
Fixes: 375553a932 ("PCI: Setup ACPI fwnode early and at the same time with OF")
Link: https://lore.kernel.org/linux-acpi/8e4bbd5c59de31db71f718556654c0aa077df03d.camel@linux.ibm.com/
Reported-by: Niklas Schnelle <schnelle@linux.ibm.com>
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Current implementation of advk_pcie_link_up() is wrong as it marks also
link disabled or hot reset states as link up.
Fix it by marking link up only to those states which are defined in PCIe
Base specification 3.0, Table 4-14: Link Status Mapped to the LTSSM.
To simplify implementation, Define macros for every LTSSM state which
aardvark hardware can return in CFG_REG register.
Fix also checking for link training according to the same Table 4-14.
Define a new function advk_pcie_link_training() for this purpose.
Link: https://lore.kernel.org/r/20211005180952.6812-13-kabel@kernel.org
Fixes: 8c39d71036 ("PCI: aardvark: Add Aardvark PCI host controller driver")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Cc: stable@vger.kernel.org
Cc: Remi Pommarel <repk@triplefau.lt>
Fix multiple link training issues in aardvark driver. The main reason of
these issues was misunderstanding of what certain registers do, since their
names and comments were misleading: before commit 96be36dbff ("PCI:
aardvark: Replace custom macros by standard linux/pci_regs.h macros"), the
pci-aardvark.c driver used custom macros for accessing standard PCIe Root
Bridge registers, and misleading comments did not help to understand what
the code was really doing.
After doing more tests and experiments I've come to the conclusion that the
SPEED_GEN register in aardvark sets the PCIe revision / generation
compliance and forces maximal link speed. Both GEN3 and GEN2 values set the
read-only PCI_EXP_FLAGS_VERS bits (PCIe capabilities version of Root
Bridge) to value 2, while GEN1 value sets PCI_EXP_FLAGS_VERS to 1, which
matches with PCI Express specifications revisions 3, 2 and 1 respectively.
Changing SPEED_GEN also sets the read-only bits PCI_EXP_LNKCAP_SLS and
PCI_EXP_LNKCAP2_SLS to corresponding speed.
(Note that PCI Express rev 1 specification does not define PCI_EXP_LNKCAP2
and PCI_EXP_LNKCTL2 registers and when SPEED_GEN is set to GEN1 (which
also sets PCI_EXP_FLAGS_VERS set to 1), lspci cannot access
PCI_EXP_LNKCAP2 and PCI_EXP_LNKCTL2 registers.)
Changing PCIe link speed can be done via PCI_EXP_LNKCTL2_TLS bits of
PCI_EXP_LNKCTL2 register. Armada 3700 Functional Specifications says that
the default value of PCI_EXP_LNKCTL2_TLS is based on SPEED_GEN value, but
tests showed that the default value is always 8.0 GT/s, independently of
speed set by SPEED_GEN. So after setting SPEED_GEN, we must also set value
in PCI_EXP_LNKCTL2 register via PCI_EXP_LNKCTL2_TLS bits.
Triggering PCI_EXP_LNKCTL_RL bit immediately after setting LINK_TRAINING_EN
bit actually doesn't do anything. Tests have shown that a delay is needed
after enabling LINK_TRAINING_EN bit. As triggering PCI_EXP_LNKCTL_RL
currently does nothing, remove it.
Commit 43fc679ced ("PCI: aardvark: Improve link training") introduced
code which sets SPEED_GEN register based on negotiated link speed from
PCI_EXP_LNKSTA_CLS bits of PCI_EXP_LNKSTA register. This code was added to
fix detection of Compex WLE900VX (Atheros QCA9880) WiFi GEN1 PCIe cards, as
otherwise these cards were "invisible" on PCIe bus (probably because they
crashed). But apparently more people reported the same issues with these
cards also with other PCIe controllers [1] and I was able to reproduce this
issue also with other "noname" WiFi cards based on Atheros QCA9890 chip
(with the same PCI vendor/device ids as Atheros QCA9880). So this is not an
issue in aardvark but rather an issue in Atheros QCA98xx chips. Also, this
issue only exists if the kernel is compiled with PCIe ASPM support, and a
generic workaround for this is to change PCIe Bridge to 2.5 GT/s link speed
via PCI_EXP_LNKCTL2_TLS_2_5GT bits in PCI_EXP_LNKCTL2 register [2], before
triggering PCI_EXP_LNKCTL_RL bit. This workaround also works when SPEED_GEN
is set to value GEN2 (5 GT/s). So remove this hack completely in the
aardvark driver and always set SPEED_GEN to value from 'max-link-speed' DT
property. Fix for Atheros QCA98xx chips is handled separately by patch [2].
These two things (code for triggering PCI_EXP_LNKCTL_RL bit and changing
SPEED_GEN value) also explain why commit 6964494582 ("PCI: aardvark:
Train link immediately after enabling training") somehow fixed detection of
those problematic Compex cards with Atheros chips: if triggering link
retraining (via PCI_EXP_LNKCTL_RL bit) was done immediately after enabling
link training (via LINK_TRAINING_EN), it did nothing. If there was a
specific delay, aardvark HW already initialized PCIe link and therefore
triggering link retraining caused the above issue. Compex cards triggered
link down event and disappeared from the PCIe bus.
Commit f4c7d053d7 ("PCI: aardvark: Wait for endpoint to be ready before
training link") added 100ms sleep before calling 'Start link training'
command and explained that it is a requirement of PCI Express
specification. But the code after this 100ms sleep was not doing 'Start
link training', rather it triggered PCI_EXP_LNKCTL_RL bit via PCIe Root
Bridge to put link into Recovery state.
The required delay after fundamental reset is already done in function
advk_pcie_wait_for_link() which also checks whether PCIe link is up.
So after removing the code which triggers PCI_EXP_LNKCTL_RL bit on PCIe
Root Bridge, there is no need to wait 100ms again. Remove the extra
msleep() call and update comment about the delay required by the PCI
Express specification.
According to Marvell Armada 3700 Functional Specifications, Link training
should be enabled via aardvark register LINK_TRAINING_EN after selecting
PCIe generation and x1 lane. There is no need to disable it prior resetting
card via PERST# signal. This disabling code was introduced in commit
5169a9851d ("PCI: aardvark: Issue PERST via GPIO") as a workaround for
some Atheros cards. It turns out that this also is Atheros specific issue
and affects any PCIe controller, not only aardvark. Moreover this Atheros
issue was triggered by juggling with PCI_EXP_LNKCTL_RL, LINK_TRAINING_EN
and SPEED_GEN bits interleaved with sleeps. Now, after removing triggering
PCI_EXP_LNKCTL_RL, there is no need to explicitly disable LINK_TRAINING_EN
bit. So remove this code too. The problematic Compex cards described in
previous git commits are correctly detected in advk_pcie_train_link()
function even after applying all these changes.
Note that with this patch, and also prior this patch, some NVMe disks which
support PCIe GEN3 with 8 GT/s speed are negotiated only at the lowest link
speed 2.5 GT/s, independently of SPEED_GEN value. After manually triggering
PCI_EXP_LNKCTL_RL bit (e.g. from userspace via setpci), these NVMe disks
change link speed to 5 GT/s when SPEED_GEN was configured to GEN2. This
issue first needs to be properly investigated. I will send a fix in the
future.
On the other hand, some other GEN2 PCIe cards with 5 GT/s speed are
autonomously by HW autonegotiated at full 5 GT/s speed without need of any
software interaction.
Armada 3700 Functional Specifications describes the following steps for
link training: set SPEED_GEN to GEN2, enable LINK_TRAINING_EN, poll until
link training is complete, trigger PCI_EXP_LNKCTL_RL, poll until signal
rate is 5 GT/s, poll until link training is complete, enable ASPM L0s.
The requirement for triggering PCI_EXP_LNKCTL_RL can be explained by the
need to achieve 5 GT/s speed (as changing link speed is done by throw to
recovery state entered by PCI_EXP_LNKCTL_RL) or maybe as a part of enabling
ASPM L0s (but in this case ASPM L0s should have been enabled prior
PCI_EXP_LNKCTL_RL).
It is unknown why the original pci-aardvark.c driver was triggering
PCI_EXP_LNKCTL_RL bit before waiting for the link to be up. This does not
align with neither PCIe base specifications nor with Armada 3700 Functional
Specification. (Note that in older versions of aardvark, this bit was
called incorrectly PCIE_CORE_LINK_TRAINING, so this may be the reason.)
It is also unknown why Armada 3700 Functional Specification says that it is
needed to trigger PCI_EXP_LNKCTL_RL for GEN2 mode, as according to PCIe
base specification 5 GT/s speed negotiation is supposed to be entirely
autonomous, even if initial speed is 2.5 GT/s.
[1] - https://lore.kernel.org/linux-pci/87h7l8axqp.fsf@toke.dk/
[2] - https://lore.kernel.org/linux-pci/20210326124326.21163-1-pali@kernel.org/
Link: https://lore.kernel.org/r/20211005180952.6812-12-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Commit 43f5c77bcb ("PCI: aardvark: Fix reporting CRS value") fixed
handling of CRS response and when CRSSVE flag was not enabled it marked CRS
response as failed transaction (due to simplicity).
But pci-aardvark.c driver is already waiting up to the PIO_RETRY_CNT count
for PIO config response and so we can with a small change implement
re-issuing of config requests as described in PCIe base specification.
This change implements re-issuing of config requests when response is CRS.
Set upper bound of wait cycles to around PIO_RETRY_CNT, afterwards the
transaction is marked as failed and an all-ones value is returned as
before.
We do this by returning appropriate error codes from function
advk_pcie_check_pio_status(). On CRS we return -EAGAIN and caller then
reissues transaction.
Link: https://lore.kernel.org/r/20211005180952.6812-10-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
The PCIE_ISR1_REG says which interrupts are currently set / active,
including those which are masked.
The driver currently reads this register and looks if some unmasked
interrupts are active, and if not, it clears status bits of _all_
interrupts, including the masked ones.
This is incorrect, since, for example, some drivers may poll these bits.
Remove this clearing, and also remove this early return statement
completely, since it does not change functionality in any way.
Link: https://lore.kernel.org/r/20211005180952.6812-7-kabel@kernel.org
Fixes: 8c39d71036 ("PCI: aardvark: Add Aardvark PCI host controller driver")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Cc: stable@vger.kernel.org
Commit 366697018c ("PCI: aardvark: Add PHY support") introduced
configuration of PCIe Reference clock via PCIE_CORE_REF_CLK_REG register,
but did it incorrectly.
PCIe Reference clock differential pair is routed from system board to
endpoint card, so on CPU side it has output direction. Therefore it is
required to enable transmitting and disable receiving.
Default configuration according to Armada 3700 Functional Specifications is
enabled receiver part and disabled transmitter.
We need this change because otherwise PCIe Reference clock is configured to
some undefined state when differential pair is used for both transmitting
and receiving.
Fix this by disabling receiver part.
Link: https://lore.kernel.org/r/20211005180952.6812-6-kabel@kernel.org
Fixes: 366697018c ("PCI: aardvark: Add PHY support")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Cc: stable@vger.kernel.org
Commit 43f5c77bcb ("PCI: aardvark: Fix reporting CRS value") started
using CRSSVE flag for handling CRS responses.
PCI_EXP_RTCTL_CRSSVE flag is stored only in emulated config space buffer
and there is handler for PCI_EXP_RTCTL register. So every read operation
from config space automatically clears CRSSVE flag as it is not defined in
PCI_EXP_RTCTL read handler.
Fix this by reading current CRSSVE bit flag from emulated space buffer and
appending it to PCI_EXP_RTCTL read response.
Link: https://lore.kernel.org/r/20211005180952.6812-5-kabel@kernel.org
Fixes: 43f5c77bcb ("PCI: aardvark: Fix reporting CRS value")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
