Emulated root bridge currently provides only one Legacy INTA interrupt
which is used for reporting PCIe PME and ERR events and handled by kernel
PCIe PME and AER drivers.
Aardvark HW reports these PME and ERR events separately, so there is no
need to mix real INTA interrupt and emulated INTA interrupt for PCIe PME
and AER drivers.
Register a new advk-RP (as in Root Port) irq chip and a new irq domain
for emulated root bridge and use this new separate irq domain for
providing INTA interrupt from emulated root bridge for PME and ERR events.
The real INTA interrupt from real devices is now separate.
A custom map_irq callback function on PCI host bridge structure is used to
allocate IRQ mapping for emulated root bridge from new irq domain. Original
callback of_irq_parse_and_map_pci() is used for all other devices as before.
Link: https://lore.kernel.org/r/20220110015018.26359-19-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>
Enable aardvark PME interrupt unconditionally by unmasking it and read PME
requester ID to emulated bridge config space immediately after receiving
interrupt.
PME requester ID is stored in the PCIE_MSG_LOG_REG register, which contains
the last inbound message. So when new inbound message is received by HW
(including non-PM), the content in PCIE_MSG_LOG_REG register is replaced by
a new value.
PCIe specification mandates that subsequent PMEs are kept pending until the
PME Status Register bit is cleared by software by writing a 1b.
Support for masking/unmasking PME interrupt on emulated bridge via
PCI_EXP_RTCTL_PMEIE bit is now implemented only in emulated bridge config
space, to ensure that we do not miss any aardvark PME interrupt.
Reading of PCI_EXP_RTCAP and PCI_EXP_RTSTA registers is simplified as final
value is now always stored into emulated bridge config space by the
interrupt handler, so there is no need to implement support for these
registers in read_pcie callback.
Clearing of W1C bit PCI_EXP_RTSTA_PME is now also simplified as it is done
by pci-bridge-emul.c code for emulated bridge config space. So there is no
need to implement support for clearing this bit in write_pcie callback.
Link: https://lore.kernel.org/r/20220110015018.26359-18-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>
Currently enabling PCI_EXP_RTSTA_PME bit in PCI_EXP_RTCTL register does
nothing. This is because PCIe PME driver expects to receive PCIe interrupt
defined in PCI_EXP_FLAGS_IRQ register, but aardvark hardware does not
trigger PCIe INTx/MSI interrupt for PME event, rather it triggers custom
aardvark interrupt which this driver is not processing yet.
Fix this issue by handling PME interrupt in advk_pcie_handle_int() and
chaining it to PCIe interrupt 0 with generic_handle_domain_irq() (since
aardvark sets PCI_EXP_FLAGS_IRQ to zero). With this change PCIe PME driver
finally starts receiving PME interrupt.
Link: https://lore.kernel.org/r/20220110015018.26359-17-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>
The emulated bridge returns incorrect value for PCI_EXP_RTSTA register
during readout in advk_pci_bridge_emul_pcie_conf_read() function: the
correct bit is BIT(16), but we are setting BIT(23), because the code
does
*value = (isr0 & PCIE_MSG_PM_PME_MASK) << 16
where
PCIE_MSG_PM_PME_MASK
is
BIT(7).
The code should probably have been something like
*value = (!!(isr0 & PCIE_MSG_PM_PME_MASK)) << 16,
but we are better of using an if() and using the proper macro for this
bit.
Link: https://lore.kernel.org/r/20220110015018.26359-15-kabel@kernel.org
Fixes: 8a3ebd8de3 ("PCI: aardvark: Implement emulated root PCI bridge config space")
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>
ERR interrupt is triggered when corresponding bit is unmasked in both ISR0
and PCI_EXP_DEVCTL registers. Unmasking ERR bits in PCI_EXP_DEVCTL register
is not enough. This means that currently the ERR interrupt is never
triggered.
Unmask ERR bits in ISR0 register at driver probe time. ERR interrupt is not
triggered until ERR bits are unmasked also in PCI_EXP_DEVCTL register,
which is done by AER driver. So it is safe to unconditionally unmask all
ERR bits in aardvark probe.
Aardvark HW sets PCI_ERR_ROOT_AER_IRQ to zero and when corresponding bits
in ISR0 and PCI_EXP_DEVCTL are enabled, the HW triggers a generic interrupt
on GIC. Chain this interrupt to PCIe interrupt 0 with
generic_handle_domain_irq() to allow processing of ERR interrupts.
Link: https://lore.kernel.org/r/20220110015018.26359-14-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>
According to PCI 3.0 specification, sending both MSI and MSI-X interrupts
is done by DWORD memory write operation to doorbell message address. The
write operation for MSI has zero upper 16 bits and the MSI interrupt number
in the lower 16 bits, while the write operation for MSI-X contains a 32-bit
value from MSI-X table.
Since the driver only uses interrupt numbers from range 0..31, the upper
16 bits of the DWORD memory write operation to doorbell message address
are zero even for MSI-X interrupts. Thus we can enable MSI-X interrupts.
Testing proves that kernel can correctly receive MSI-X interrupts from PCIe
cards which supports both MSI and MSI-X interrupts.
Link: https://lore.kernel.org/r/20220110015018.26359-13-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>
MSI address for receiving MSI interrupts needs to be correctly set before
enabling processing of MSI interrupts.
Move code for setting PCIE_MSI_ADDR_LOW_REG and PCIE_MSI_ADDR_HIGH_REG
from advk_pcie_init_msi_irq_domain() to advk_pcie_setup_hw(), before
enabling PCIE_CORE_CTRL2_MSI_ENABLE.
After this we can remove the now unused member msi_msg, which was used
only for MSI doorbell address. MSI address can be any address which cannot
be used to DMA to. So change it to the address of the main struct advk_pcie.
Link: https://lore.kernel.org/r/20220110015018.26359-12-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>
Acked-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org # f21a8b1b68 ("PCI: aardvark: Move to MSI handling using generic MSI support")
Rewrite the code to use irq_set_chained_handler_and_data() handler with
chained_irq_enter() and chained_irq_exit() processing instead of using
devm_request_irq().
advk_pcie_irq_handler() reads IRQ status bits and calls other functions
based on which bits are set. These functions then read its own IRQ status
bits and calls other aardvark functions based on these bits. Finally
generic_handle_domain_irq() with translated linux IRQ numbers are called.
Link: https://lore.kernel.org/r/20220110015018.26359-5-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>
Aardvark hardware supports Multi-MSI and MSI_FLAG_MULTI_PCI_MSI is already
set for the MSI chip. But when allocating MSI interrupt numbers for
Multi-MSI, the numbers need to be properly aligned, otherwise endpoint
devices send MSI interrupt with incorrect numbers.
Fix this issue by using function bitmap_find_free_region() instead of
bitmap_find_next_zero_area().
To ensure that aligned MSI interrupt numbers are used by endpoint devices,
we cannot use Linux virtual irq numbers (as they are random and not
properly aligned). Instead we need to use the aligned hwirq numbers.
This change fixes receiving MSI interrupts on Armada 3720 boards and
allows using NVMe disks which use Multi-MSI feature with 3 interrupts.
Without this NVMe disks freeze booting as linux nvme-core.c is waiting
60s for an interrupt.
Link: https://lore.kernel.org/r/20220110015018.26359-4-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>
In advk_pcie_handle_msi() it is expected that when bit i in the W1C
register PCIE_MSI_STATUS_REG is cleared, the PCIE_MSI_PAYLOAD_REG is
updated to contain the MSI number corresponding to index i.
Experiments show that this is not so, and instead PCIE_MSI_PAYLOAD_REG
always contains the number of the last received MSI, overall.
Do not read PCIE_MSI_PAYLOAD_REG register for determining MSI interrupt
number. Since Aardvark already forbids more than 32 interrupts and uses
own allocated hwirq numbers, the msi_idx already corresponds to the
received MSI number.
Link: https://lore.kernel.org/r/20220110015018.26359-3-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>
Pull pci updates from Bjorn Helgaas:
"Enumeration:
- 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)
Resource management:
- Always write Intel I210 ROM BAR on update to work around device
defect (Bjorn Helgaas)
PCIe native device hotplug:
- Fix pciehp lockdep errors on Thunderbolt undock (Hans de Goede)
- Fix infinite loop in pciehp IRQ handler on power fault (Lukas
Wunner)
Power management:
- Convert amd64-agp, sis-agp, via-agp from legacy PCI power
management to generic power management (Vaibhav Gupta)
IOMMU:
- Add function 1 DMA alias quirk for Marvell 88SE9125 SATA controller
so it can work with an IOMMU (Yifeng Li)
Error handling:
- Add PCI_ERROR_RESPONSE and related definitions for signaling and
checking for transaction errors on PCI (Naveen Naidu)
- Fabricate PCI_ERROR_RESPONSE data (~0) in config read wrappers,
instead of in host controller drivers, when transactions fail on
PCI (Naveen Naidu)
- Use PCI_POSSIBLE_ERROR() to check for possible failure of config
reads (Naveen Naidu)
Peer-to-peer DMA:
- Add Logan Gunthorpe as P2PDMA maintainer (Bjorn Helgaas)
ASPM:
- Calculate link L0s and L1 exit latencies when needed instead of
caching them (Saheed O. Bolarinwa)
- Calculate device L0s and L1 acceptable exit latencies when needed
instead of caching them (Saheed O. Bolarinwa)
- Remove struct aspm_latency since it's no longer needed (Saheed O.
Bolarinwa)
APM X-Gene PCIe controller driver:
- Fix IB window setup, which was broken by the fact that IB resources
are now sorted in address order instead of DT dma-ranges order (Rob
Herring)
Apple PCIe controller driver:
- Enable clock gating to save power (Hector Martin)
- Fix REFCLK1 enable/poll logic (Hector Martin)
Broadcom STB PCIe controller driver:
- Declare bitmap correctly for use by bitmap interfaces (Christophe
JAILLET)
- Clean up computation of legacy and non-legacy MSI bitmasks (Florian
Fainelli)
- Update suspend/resume/remove error handling to warn about errors
and not fail the operation (Jim Quinlan)
- Correct the "pcie" and "msi" interrupt descriptions in DT binding
(Jim Quinlan)
- Add DT bindings for endpoint voltage regulators (Jim Quinlan)
- Split brcm_pcie_setup() into two functions (Jim Quinlan)
- Add mechanism for turning on voltage regulators for connected
devices (Jim Quinlan)
- Turn voltage regulators for connected devices on/off when bus is
added or removed (Jim Quinlan)
- When suspending, don't turn off voltage regulators for wakeup
devices (Jim Quinlan)
Freescale i.MX6 PCIe controller driver:
- Add i.MX8MM support (Richard Zhu)
Freescale Layerscape PCIe controller driver:
- Use DWC common ops instead of layerscape-specific link-up functions
(Hou Zhiqiang)
Intel VMD host bridge driver:
- Honor platform ACPI _OSC feature negotiation for Root Ports below
VMD (Kai-Heng Feng)
- Add support for Raptor Lake SKUs (Karthik L Gopalakrishnan)
- Reset everything below VMD before enumerating to work around
failure to enumerate NVMe devices when guest OS reboots (Nirmal
Patel)
Bridge emulation (used by Marvell Aardvark and MVEBU):
- Make emulated ROM BAR read-only by default (Pali Rohár)
- Make some emulated legacy PCI bits read-only for PCIe devices (Pali
Rohár)
- Update reserved bits in emulated PCIe Capability (Pali Rohár)
- Allow drivers to emulate different PCIe Capability versions (Pali
Rohár)
- Set emulated Capabilities List bit for all PCIe devices, since they
must have at least a PCIe Capability (Pali Rohár)
Marvell Aardvark PCIe controller driver:
- Add bridge emulation definitions for PCIe DEVCAP2, DEVCTL2,
DEVSTA2, LNKCAP2, LNKCTL2, LNKSTA2, SLTCAP2, SLTCTL2, SLTSTA2 (Pali
Rohár)
- Add aardvark support for DEVCAP2, DEVCTL2, LNKCAP2 and LNKCTL2
registers (Pali Rohár)
- Clear all MSIs at setup to avoid spurious interrupts (Pali Rohár)
- Disable bus mastering when unbinding host controller driver (Pali
Rohár)
- Mask all interrupts when unbinding host controller driver (Pali
Rohár)
- Fix memory leak in host controller unbind (Pali Rohár)
- Assert PERST# when unbinding host controller driver (Pali Rohár)
- Disable link training when unbinding host controller driver (Pali
Rohár)
- Disable common PHY when unbinding host controller driver (Pali
Rohár)
- Fix resource type checking to check only IORESOURCE_MEM, not
IORESOURCE_MEM_64, which is a flavor of IORESOURCE_MEM (Pali Rohár)
Marvell MVEBU PCIe controller driver:
- Implement pci_remap_iospace() for ARM so mvebu can use
devm_pci_remap_iospace() instead of the previous ARM-specific
pci_ioremap_io() interface (Pali Rohár)
- Use the standard pci_host_probe() instead of the device-specific
mvebu_pci_host_probe() (Pali Rohár)
- Replace all uses of ARM-specific pci_ioremap_io() with the ARM
implementation of the standard pci_remap_iospace() interface and
remove pci_ioremap_io() (Pali Rohár)
- Skip initializing invalid Root Ports (Pali Rohár)
- Check for errors from pci_bridge_emul_init() (Pali Rohár)
- Ignore any bridges at non-zero function numbers (Pali Rohár)
- Return ~0 data for invalid config read size (Pali Rohár)
- Disallow mapping interrupts on emulated bridges (Pali Rohár)
- Clear Root Port Memory & I/O Space Enable and Bus Master Enable at
initialization (Pali Rohár)
- Make type bits in Root Port I/O Base register read-only (Pali
Rohár)
- Disable Root Port windows when base/limit set to invalid values
(Pali Rohár)
- Set controller to Root Complex mode (Pali Rohár)
- Set Root Port Class Code to PCI Bridge (Pali Rohár)
- Update emulated Root Port secondary bus numbers to better reflect
the actual topology (Pali Rohár)
- Add PCI_BRIDGE_CTL_BUS_RESET support to emulated Root Ports so
pci_reset_secondary_bus() can reset connected devices (Pali Rohár)
- Add PCI_EXP_DEVCTL Error Reporting Enable support to emulated Root
Ports (Pali Rohár)
- Add PCI_EXP_RTSTA PME Status bit support to emulated Root Ports
(Pali Rohár)
- Add DEVCAP2, DEVCTL2 and LNKCTL2 support to emulated Root Ports on
Armada XP and newer devices (Pali Rohár)
- Export mvebu-mbus.c symbols to allow pci-mvebu.c to be a module
(Pali Rohár)
- Add support for compiling as a module (Pali Rohár)
MediaTek PCIe controller driver:
- Assert PERST# for 100ms to allow power and clock to stabilize
(qizhong cheng)
MediaTek PCIe Gen3 controller driver:
- Disable Mediatek DVFSRC voltage request since lack of DVFSRC to
respond to the request causes failure to exit L1 PM Substate
(Jianjun Wang)
MediaTek MT7621 PCIe controller driver:
- Declare mt7621_pci_ops static (Sergio Paracuellos)
- Give pcibios_root_bridge_prepare() access to host bridge windows
(Sergio Paracuellos)
- Move MIPS I/O coherency unit setup from driver to
pcibios_root_bridge_prepare() (Sergio Paracuellos)
- Add missing MODULE_LICENSE() (Sergio Paracuellos)
- Allow COMPILE_TEST for all arches (Sergio Paracuellos)
Microsoft Hyper-V host bridge driver:
- Add hv-internal interfaces to encapsulate arch IRQ dependencies
(Sunil Muthuswamy)
- Add arm64 Hyper-V vPCI support (Sunil Muthuswamy)
Qualcomm PCIe controller driver:
- Undo PM setup in qcom_pcie_probe() error handling path (Christophe
JAILLET)
- Use __be16 type to store return value from cpu_to_be16()
(Manivannan Sadhasivam)
- Constify static dw_pcie_ep_ops (Rikard Falkeborn)
Renesas R-Car PCIe controller driver:
- Fix aarch32 abort handler so it doesn't check the wrong bus clock
before accessing the host controller (Marek Vasut)
TI Keystone PCIe controller driver:
- Add register offset for ti,syscon-pcie-id and ti,syscon-pcie-mode
DT properties (Kishon Vijay Abraham I)
MicroSemi Switchtec management driver:
- Add Gen4 automotive device IDs (Kelvin Cao)
- Declare state_names[] as static so it's not allocated and
initialized for every call (Kelvin Cao)
Host controller driver cleanups:
- Use of_device_get_match_data(), not of_match_device(), when we only
need the device data in altera, artpec6, cadence, designware-plat,
dra7xx, keystone, kirin (Fan Fei)
- Drop pointless of_device_get_match_data() cast in j721e (Bjorn
Helgaas)
- Drop redundant struct device * from j721e since struct cdns_pcie
already has one (Bjorn Helgaas)
- Rename driver structs to *_pcie in intel-gw, iproc, ls-gen4,
mediatek-gen3, microchip, mt7621, rcar-gen2, tegra194, uniphier,
xgene, xilinx, xilinx-cpm for consistency across drivers (Fan Fei)
- Fix invalid address space conversions in hisi, spear13xx (Bjorn
Helgaas)
Miscellaneous:
- Sort Intel Device IDs by value (Andy Shevchenko)
- Change Capability offsets to hex to match spec (Baruch Siach)
- Correct misspellings (Krzysztof Wilczyński)
- Terminate statement with semicolon in pci_endpoint_test.c (Ming
Wang)"
* tag 'pci-v5.17-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (151 commits)
PCI: mt7621: Allow COMPILE_TEST for all arches
PCI: mt7621: Add missing MODULE_LICENSE()
PCI: mt7621: Move MIPS setup to pcibios_root_bridge_prepare()
PCI: Let pcibios_root_bridge_prepare() access bridge->windows
PCI: mt7621: Declare mt7621_pci_ops static
PCI: brcmstb: Do not turn off WOL regulators on suspend
PCI: brcmstb: Add control of subdevice voltage regulators
PCI: brcmstb: Add mechanism to turn on subdev regulators
PCI: brcmstb: Split brcm_pcie_setup() into two funcs
dt-bindings: PCI: Add bindings for Brcmstb EP voltage regulators
dt-bindings: PCI: Correct brcmstb interrupts, interrupt-map.
PCI: brcmstb: Fix function return value handling
PCI: brcmstb: Do not use __GENMASK
PCI: brcmstb: Declare 'used' as bitmap, not unsigned long
PCI: hv: Add arm64 Hyper-V vPCI support
PCI: hv: Make the code arch neutral by adding arch specific interfaces
PCI: pciehp: Use down_read/write_nested(reset_lock) to fix lockdep errors
x86/PCI: Remove initialization of static variables to false
PCI: Use DWORD accesses for LTR, L1 SS to avoid erratum
misc: pci_endpoint_test: Terminate statement with semicolon
...
- Add PCI_ERROR_RESPONSE and related definitions for signaling and checking
for transaction errors on PCI (Naveen Naidu)
- Fabricate PCI_ERROR_RESPONSE data (~0) in config read wrappers, instead
of in host controller drivers, when transactions fail on PCI (Naveen
Naidu)
- Use PCI_POSSIBLE_ERROR() to check for possible failure of config reads
(Naveen Naidu)
* pci/errors:
PCI: xgene: Use PCI_ERROR_RESPONSE to identify config read errors
PCI: hv: Use PCI_ERROR_RESPONSE to identify config read errors
PCI: keystone: Use PCI_ERROR_RESPONSE to identify config read errors
PCI: Use PCI_ERROR_RESPONSE to identify config read errors
PCI: cpqphp: Use PCI_POSSIBLE_ERROR() to check config reads
PCI/PME: Use PCI_POSSIBLE_ERROR() to check config reads
PCI/DPC: Use PCI_POSSIBLE_ERROR() to check config reads
PCI: pciehp: Use PCI_POSSIBLE_ERROR() to check config reads
PCI: vmd: Use PCI_POSSIBLE_ERROR() to check config reads
PCI/ERR: Use PCI_POSSIBLE_ERROR() to check config reads
PCI: rockchip-host: Drop error data fabrication when config read fails
PCI: rcar-host: Drop error data fabrication when config read fails
PCI: altera: Drop error data fabrication when config read fails
PCI: mvebu: Drop error data fabrication when config read fails
PCI: aardvark: Drop error data fabrication when config read fails
PCI: kirin: Drop error data fabrication when config read fails
PCI: histb: Drop error data fabrication when config read fails
PCI: exynos: Drop error data fabrication when config read fails
PCI: mediatek: Drop error data fabrication when config read fails
PCI: iproc: Drop error data fabrication when config read fails
PCI: thunder: Drop error data fabrication when config read fails
PCI: Drop error data fabrication when config read fails
PCI: Use PCI_SET_ERROR_RESPONSE() for disconnected devices
PCI: Set error response data when config read fails
PCI: Add PCI_ERROR_RESPONSE and related definitions
- Make emulated ROM BAR read-only by default (Pali Rohár)
- Make some emulated legacy PCI bits read-only for PCIe devices (Pali
Rohár)
- Update reserved bits in emulated PCIe Capability (Pali Rohár)
- Allow drivers to emulate different PCIe Capability versions (Pali Rohár)
- Set emulated Capabilities List bit for all PCIe devices, since they must
have at least a PCIe Capability (Pali Rohár)
* remotes/lorenzo/pci/bridge-emul:
PCI: pci-bridge-emul: Set PCI_STATUS_CAP_LIST for PCIe device
PCI: pci-bridge-emul: Correctly set PCIe capabilities
PCI: pci-bridge-emul: Fix definitions of reserved bits
PCI: pci-bridge-emul: Properly mark reserved PCIe bits in PCI config space
PCI: pci-bridge-emul: Make expansion ROM Base Address register read-only
Older mvebu hardware provides PCIe Capability structure only in version 1.
New mvebu and aardvark hardware provides it in version 2. So do not force
version to 2 in pci_bridge_emul_init() and rather allow drivers to set
correct version. Drivers need to set version in pcie_conf.cap field without
overwriting PCI_CAP_LIST_ID register. Both drivers (mvebu and aardvark) do
not provide slot support yet, so do not set PCI_EXP_FLAGS_SLOT flag.
Link: https://lore.kernel.org/r/20211124155944.1290-6-pali@kernel.org
Fixes: 23a5fba4d9 ("PCI: Introduce PCI bridge emulated config space common logic")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org
This reverts commit 239edf686c.
239edf686c ("PCI: aardvark: Fix support for PCI_ROM_ADDRESS1 on emulated
bridge") added support for the Type 1 Expansion ROM BAR at config offset
0x38, based on the register being listed in the Marvell Armada A3720 spec.
But the spec doesn't document it at all for RC mode, and there is no ROM in
the SOC, so remove this emulation for now.
The PCI bridge which represents aardvark's PCIe Root Port has an Expansion
ROM Base Address register at offset 0x30, but its meaning is different than
PCI's Expansion ROM BAR register, although the layout is the same. (This
is why we thought it does the same thing.)
First: there is no ROM (or part of BootROM) in the A3720 SOC dedicated for
PCIe Root Port (or controller in RC mode) containing executable code that
would initialize the Root Port, suitable for execution in bootloader (this
is how Expansion ROM BAR is used on x86).
Second: in A3720 spec the register (address 0xD0070030) is not documented
at all for Root Complex mode, but similar to other BAR registers, it has an
"entangled partner" in register 0xD0075920, which does address translation
for the BAR in 0xD0070030:
- the BAR register sets the address from the view of PCIe bus
- the translation register sets the address from the view of the CPU
The other BAR registers also have this entangled partner, and they can be
used to:
- in RC mode: address-checking on the receive side of the RC (they can
define address ranges for memory accesses from remote Endpoints to the
RC)
- in Endpoint mode: allow the remote CPU to access memory on A3720
The Expansion ROM BAR has only the Endpoint part documented, but from the
similarities we think that it can also be used in RC mode in that way.
So either Expansion ROM BAR has different meaning (if the hypothesis above
is true), or we don't know it's meaning (since it is not documented for RC
mode).
Remove the register from the emulated bridge accessing functions.
[bhelgaas: summarize reason for removal (first paragraph)]
Fixes: 239edf686c ("PCI: aardvark: Fix support for PCI_ROM_ADDRESS1 on emulated bridge")
Link: https://lore.kernel.org/r/20211125160148.26029-3-kabel@kernel.org
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Pali Rohár <pali@kernel.org>
Aardvark controller has something like config space of a Root Port
available at offset 0x0 of internal registers - these registers are used
for implementation of the emulated bridge.
The default value of Class Code of this bridge corresponds to a RAID Mass
storage controller, though. (This is probably intended for when the
controller is used as Endpoint.)
Change the Class Code to correspond to a PCI Bridge.
Add comment explaining this change.
Link: https://lore.kernel.org/r/20211028185659.20329-6-kabel@kernel.org
Fixes: 8a3ebd8de3 ("PCI: aardvark: Implement emulated root PCI bridge config space")
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>
Cc: stable@vger.kernel.org
From very vague, ambiguous and incomplete information from Marvell we
deduced that the 32-bit Aardvark register at address 0x4
(PCIE_CORE_CMD_STATUS_REG), which is not documented for Root Complex mode
in the Functional Specification (only for Endpoint mode), controls two
16-bit PCIe registers: Command Register and Status Registers of PCIe Root
Port.
This means that bit 2 controls bus mastering and forwarding of memory and
I/O requests in the upstream direction. According to PCI specifications
bits [0:2] of Command Register, this should be by default disabled on
reset. So explicitly disable these bits at early setup of the Aardvark
driver.
Remove code which unconditionally enables all 3 bits and let kernel code
(via pci_set_master() function) to handle bus mastering of Root PCIe
Bridge via emulated PCI_COMMAND on emulated bridge.
Link: https://lore.kernel.org/r/20211028185659.20329-5-kabel@kernel.org
Fixes: 8a3ebd8de3 ("PCI: aardvark: Implement emulated root PCI bridge config space")
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>
Cc: stable@vger.kernel.org # b2a56469d5 ("PCI: aardvark: Add FIXME comment for PCIE_CORE_CMD_STATUS_REG access")
MSI domain callback .alloc() (implemented by advk_msi_irq_domain_alloc()
function) should return zero on success, since non-zero value indicates
failure.
When the driver was converted to generic MSI API in commit f21a8b1b68
("PCI: aardvark: Move to MSI handling using generic MSI support"), it
was converted so that it returns hwirq number.
Fix this.
Link: https://lore.kernel.org/r/20211028185659.20329-3-kabel@kernel.org
Fixes: f21a8b1b68 ("PCI: aardvark: Move to MSI handling using generic MSI 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>
Cc: stable@vger.kernel.org
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>
