Add RX lane margining settings for 16.0 GT/s (GEN 4) data rate.
These settings improve link stability while operating at high date
rates and helps to improve signal quality.
Link: https://lore.kernel.org/linux-pci/20240911-pci-qcom-gen4-stability-v7-4-743f5c1fd027@linaro.org
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Shashank Babu Chinta Venkata <quic_schintav@quicinc.com>
[mani: dropped the code refactoring and minor changes]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
During high data transmission rates such as 16.0 GT/s, there is an
increased risk of signal loss due to poor channel quality and
interference. This can impact receiver's ability to capture signals
accurately.
Hence, as signal compensation is achieved through appropriate lane
equalization, apply lane equalization settings at both transmitter
and receiver which results in an increase in the PCIe signal strength.
While at it, modify the pcie-tegra194 driver to make use of the
common GEN3_EQ_CONTROL_OFF definitions in pcie-designware.h.
Link: https://lore.kernel.org/linux-pci/20240911-pci-qcom-gen4-stability-v7-3-743f5c1fd027@linaro.org
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Shashank Babu Chinta Venkata <quic_schintav@quicinc.com>
[mani: dropped the code refactoring and minor changes]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Currently, the dw_pcie::max_link_speed has a valid value only if the
controller driver restricts the maximum link speed in the driver or if
the platform does so in the devicetree using the 'max-link-speed'
property.
But having the maximum supported link speed of the platform would be
helpful for the vendor drivers to configure any link specific settings.
So in the case of non-valid value in dw_pcie::max_link_speed, just cache
the hardware default value from Link Capability register.
While at it, remove the 'max_link_speed' argument to the
dw_pcie_link_set_max_speed() function since the value can be
retrieved within the function.
Link: https://lore.kernel.org/linux-pci/20240911-pci-qcom-gen4-stability-v7-2-743f5c1fd027@linaro.org
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
The 'link_gen' field is now holding the maximum supported link speed set
either by the controller driver or by DT through 'max-link-speed'
property.
However, the name 'link_gen' sounds like the negotiated link speed of
the PCIe link.
So rename it to 'max_link_speed' to make it clear that it holds the
maximum supported link speed of the controller.
Link: https://lore.kernel.org/linux-pci/20240911-pci-qcom-gen4-stability-v7-1-743f5c1fd027@linaro.org
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
qcom_pcie_enable_resources() is called by qcom_pcie_ep_probe() and it
enables the controller resources like clocks, regulator, PHY. On one of the
new unreleased Qcom SoC, PHY enablement depends on the active refclk. And
on all of the supported Qcom endpoint SoCs, refclk comes from the host
(RC). So calling qcom_pcie_enable_resources() without refclk causes the
NoC (Network On Chip) error in the endpoint SoC and in turn results in a
whole SoC crash and rebooting into EDL (Emergency Download) mode which is
an unrecoverable state.
But qcom_pcie_enable_resources() is already called by
qcom_pcie_perst_deassert() when PERST# is deasserted, and refclk is
available at that time.
Hence, remove the unnecessary call to qcom_pcie_enable_resources() from
qcom_pcie_ep_probe() to prevent the above mentioned crash.
It should be noted that this commit prevents the crash only under normal
working condition (booting endpoint before host), but the crash may also
occur if PERST# assert happens at the wrong time. For avoiding the crash
completely, it is recommended to use SRIS mode which allows the endpoint
SoC to generate its own refclk. The driver is not supporting SRIS mode
currently, but will be added in the future.
Fixes: 869bc52534 ("PCI: dwc: ep: Fix DBI access failure for drivers requiring refclk from host")
Link: https://lore.kernel.org/linux-pci/20240830082319.51387-1-manivannan.sadhasivam@linaro.org
Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
PARF hardware block which is a wrapper on top of DWC PCIe controller
mirrors the DBI and ATU register space. It uses PARF_SLV_ADDR_SPACE_SIZE
register to get the size of the memory block to be mirrored and uses
PARF_DBI_BASE_ADDR, PARF_ATU_BASE_ADDR registers to determine the base
address of DBI and ATU space inside the memory block that is being
mirrored.
When a memory region which is located above the SLV_ADDR_SPACE_SIZE
boundary is used for BAR region then there could be an overlap of DBI and
ATU address space that is getting mirrored and the BAR region. This
results in DBI and ATU address space contents getting updated when a PCIe
function driver tries updating the BAR/MMIO memory region. Reference
memory map of the PCIe memory region with DBI and ATU address space
overlapping BAR region is as below.
|---------------|
| |
| |
------- --------|---------------|
| | |---------------|
| | | DBI |
| | |---------------|---->DBI_BASE_ADDR
| | | |
| | | |
| PCIe | |---->2*SLV_ADDR_SPACE_SIZE
| BAR/MMIO|---------------|
| Region | ATU |
| | |---------------|---->ATU_BASE_ADDR
| | | |
PCIe | |---------------|
Memory | | DBI |
Region | |---------------|---->DBI_BASE_ADDR
| | | |
| --------| |
| | |---->SLV_ADDR_SPACE_SIZE
| |---------------|
| | ATU |
| |---------------|---->ATU_BASE_ADDR
| | |
| |---------------|
| | DBI |
| |---------------|---->DBI_BASE_ADDR
| | |
| | |
----------------|---------------|
| |
| |
| |
|---------------|
Currently memory region beyond the SLV_ADDR_SPACE_SIZE boundary is not
used for BAR region which is why the above mentioned issue is not
encountered. This issue is discovered as part of internal testing when we
tried moving the BAR region beyond the SLV_ADDR_SPACE_SIZE boundary. Hence
we are trying to fix this.
As PARF hardware block mirrors DBI and ATU register space after every
PARF_SLV_ADDR_SPACE_SIZE (default 0x1000000) boundary multiple, program
maximum possible size to this register by writing 0x80000000 to it(it
considers only powers of 2 as values) to avoid mirroring DBI and ATU to
BAR/MMIO region. Write the physical base address of DBI and ATU register
blocks to PARF_DBI_BASE_ADDR (default 0x0) and PARF_ATU_BASE_ADDR (default
0x1000) respectively to make sure DBI and ATU blocks are at expected
memory locations.
The register offsets PARF_DBI_BASE_ADDR_V2, PARF_SLV_ADDR_SPACE_SIZE_V2
and PARF_ATU_BASE_ADDR are applicable for platforms that use Qcom IP
rev 1.9.0, 2.7.0 and 2.9.0. PARF_DBI_BASE_ADDR_V2 and
PARF_SLV_ADDR_SPACE_SIZE_V2 are applicable for Qcom IP rev 2.3.3.
PARF_DBI_BASE_ADDR and PARF_SLV_ADDR_SPACE_SIZE are applicable for Qcom
IP rev 1.0.0, 2.3.2 and 2.4.0. Update init()/post_init() functions of the
respective Qcom IP versions to program applicable PARF_DBI_BASE_ADDR,
PARF_SLV_ADDR_SPACE_SIZE and PARF_ATU_BASE_ADDR register offsets. Update
the SLV_ADDR_SPACE_SZ macro to 0x80000000 to set highest bit in
PARF_SLV_ADDR_SPACE_SIZE register.
Cache DBI and iATU physical addresses in 'struct dw_pcie' so that
pcie_qcom.c driver can program these addresses in the PARF_DBI_BASE_ADDR
and PARF_ATU_BASE_ADDR registers.
Suggested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/linux-pci/20240814220338.1969668-1-quic_pyarlaga@quicinc.com
Signed-off-by: Prudhvi Yarlagadda <quic_pyarlaga@quicinc.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Mayank Rana <quic_mrana@quicinc.com>
Historically, Qcom PCIe RC controllers lacked standard hotplug support. So
when an endpoint is attached to the SoC, users have to rescan the bus
manually to enumerate the device. But this can be avoided by using the Link
up event exposed by the Qcom specific 'global_irq' interrupt.
Qcom PCIe RC controllers are capable of generating the 'global' SPI
interrupt to the host CPUs. The device driver can use this interrupt to
identify events such as PCIe link specific events, safety events etc...
One such event is the PCIe Link up event generated when an endpoint is
detected on the bus and the Link is 'up'. This event can be used to
enumerate the PCIe endpoint devices without user intervention.
So add support for capturing the PCIe Link up event using the 'global'
interrupt in the driver. Once the Link up event is received, the bus
underneath the host bridge is scanned to enumerate PCIe endpoint devices.
All of the Qcom SoCs have only one Root Port per controller instance. So
only a single 'Link up' event is generated for the PCIe controller.
Link: https://lore.kernel.org/linux-pci/20240828-pci-qcom-hotplug-v4-11-263a385fbbcb@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Currently, the IRQ device name for both of these IRQs doesn't have Qcom
specific prefix and PCIe domain number. This causes 2 issues:
1. Pollutes the global IRQ namespace since 'global' is a common name.
2. When more than one EP controller instance is present in the SoC, naming
conflict will occur.
Hence, add 'qcom_pcie_ep_' prefix and PCIe domain number suffix to the IRQ
names to uniquely identify the IRQs and also to fix the above mentioned
issues.
Link: https://lore.kernel.org/linux-pci/20240828-pci-qcom-hotplug-v4-6-263a385fbbcb@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Current error message just prints the contents of PARF_INT_ALL_STATUS
register as if like the IRQ event number. It could mislead the users.
Reword it to make it clear that the error message is actually showing the
interrupt status register to help debug spurious IRQ events.
While at it, let's also switch over to dev_WARN_ONCE() so that any IRQ
storm won't flood the kernel log buffer.
Link: https://lore.kernel.org/linux-pci/20240828-pci-qcom-hotplug-v4-2-263a385fbbcb@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Once the events are disabled in PARF_INT_ALL_MASK register, only the
enabled events will generate global IRQ. So there is no need to do the
masking again in the IRQ handler, drop it.
If there are any spurious IRQs getting generated, they will be reported
using the existing dev_err() in the handler.
Link: https://lore.kernel.org/linux-pci/20240828-pci-qcom-hotplug-v4-1-263a385fbbcb@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
- Remove unused struct 'acpi_handle_node' (Dr. David Alan Gilbert)
- Use array notation for portdrv .id_table consistently (Masahiro Yamada)
- Switch to new Intel CPU model defines (Tony Luck)
- Add missing MODULE_DESCRIPTION() macros (Jeff Johnson)
* pci/misc:
PCI: controller: Add missing MODULE_DESCRIPTION() macros
PCI: Add missing MODULE_DESCRIPTION() macros
PCI/PM: Switch to new Intel CPU model defines
PCI: Use array for .id_table consistently
ACPI: PCI: Remove unused struct 'acpi_handle_node'
- Ensure Tegra194 and Tegra234 inbound ATU entries are 64KB-aligned to
match the hardware restriction (Jon Hunter)
- Remove unused struct 'tegra_pcie_soc' (Dr. David Alan Gilbert)
* pci/controller/tegra194:
PCI: tegra: Remove unused struct 'tegra_pcie_soc'
PCI: tegra194: Set EP alignment restriction for inbound ATU
- Use dev_err_probe() in dw-rockchip probe error path so the failures
aren't silent (Uwe Kleine-König)
- Sleep PCIE_T_PVPERL_MS (100ms) before deasserting PERST# (Damien Le Moal)
- Sleep PCIE_T_RRS_READY_MS (100ms) after conventional reset, before a
config access (Damien Le Moal)
- Request the PERST# GPIO with GPIOD_OUT_LOW so it matches the POR value,
which avoids a spurious PERST# assertion and fixes a Qcom modem firmware
crash and issues with WLAN controllers, e.g., RTL8822CE (Manivannan
Sadhasivam for rockchip, Niklas Cassel for dw-rockchip)
- Refactor dw-rockchip and add support for Endpoint mode for rk3568 and
rk3588 (Niklas Cassel)
* pci/controller/rockchip:
PCI: dw-rockchip: Use pci_epc_init_notify() directly
PCI: dw-rockchip: Add endpoint mode support
PCI: dw-rockchip: Refactor the driver to prepare for EP mode
PCI: dw-rockchip: Add rockchip_pcie_get_ltssm() helper
PCI: dw-rockchip: Fix weird indentation
PCI: dw-rockchip: Fix initial PERST# GPIO value
PCI: dw-rockchip: Add error messages in .probe() error paths
PCI: rockchip: Use GPIOD_OUT_LOW flag while requesting ep_gpio
PCI: rockchip-host: Wait 100ms after reset before starting configuration
PCI: rockchip-host: Fix rockchip_pcie_host_init_port() PERST# handling
- Add Synopsys DWC macros for lane skew configuration (Yoshihiro Shimoda)
- Add struct rcar_gen4_pcie_drvdata to provide for future SoCs with
different initialization requirements (Yoshihiro Shimoda)
- Add .ltssm_control() method for SoC dependencies (Yoshihiro Shimoda)
- Add r8a779g0 (R-Car V4H) support (Yoshihiro Shimoda)
* pci/controller/rcar-gen4:
PCI: rcar-gen4: Add support for R-Car V4H
PCI: rcar-gen4: Add .ltssm_control() for other SoC support
PCI: rcar-gen4: Add struct rcar_gen4_pcie_drvdata
PCI: dwc: Add PCIE_PORT_{FORCE,LANE_SKEW} macros
- Use devm_clk_bulk_get_all() to get all the clocks from DT to avoid
writing out all the clock names (Manivannan Sadhasivam)
- Add DT binding and driver support for the SA8775P SoC (Mrinmay Sarkar)
- Refactor dw_pcie_edma_find_chip() to enable adding support for Hyper DMA
(HDMA) (Manivannan Sadhasivam)
- Enable drivers to supply the eDMA channel count since some can't auto
detect this (Manivannan Sadhasivam)
- Add HDMA support for the SA8775P SoC (Mrinmay Sarkar)
- Override the SA8775P NO_SNOOP default to avoid possible memory corruption
(Mrinmay Sarkar)
- Make sure resources are disabled during PERST# assertion, even if the
link is already disabled (Manivannan Sadhasivam)
- Vote for the CPU-PCIe ICC (interconnect) path to ensure it stays active
even if other drivers don't vote for it (Krishna chaitanya chundru)
- Add Operating Performance Points (OPP) to scale performance state based
on aggregate link bandwidth to improve SoC power efficiency (Krishna
chaitanya chundru)
- Return failure instead of success if dev_pm_opp_find_freq_floor() fails
(Dan Carpenter)
- Avoid an error pointer dereference if dev_pm_opp_find_freq_exact() fails
(Dan Carpenter)
- Prevent use of uninitialized data in qcom_pcie_suspend_noirq() (Dan
Carpenter)
* pci/controller/qcom:
PCI: qcom: Prevent use of uninitialized data in qcom_pcie_suspend_noirq()
PCI: qcom: Prevent potential error pointer dereference
PCI: qcom: Fix missing error code in qcom_pcie_probe()
PCI: qcom: Add OPP support to scale performance
PCI: Bring the PCIe speed to MBps logic to new pcie_dev_speed_mbps()
PCI: qcom: Add ICC bandwidth vote for CPU to PCIe path
PCI: qcom-ep: Disable resources unconditionally during PERST# assert
PCI: qcom-ep: Override NO_SNOOP attribute for SA8775P EP
PCI: qcom: Override NO_SNOOP attribute for SA8775P RC
PCI: epf-mhi: Enable HDMA for SA8775P SoC
PCI: qcom-ep: Add HDMA support for SA8775P SoC
PCI: dwc: Pass the eDMA mapping format flag directly from glue drivers
PCI: dwc: Skip finding eDMA channels count for HDMA platforms
PCI: dwc: Refactor dw_pcie_edma_find_chip() API
PCI: qcom-ep: Add support for SA8775P SOC
dt-bindings: PCI: qcom-ep: Add support for SA8775P SoC
PCI: qcom: Use devm_clk_bulk_get_all() API
- Enable BAR 0 only for v3.65a to avoid Completion Timeouts that
cause a 45 second boot delay on the v4.90a-based AM654x SoC (Siddharth
Vadapalli)
- Avoid a NULL pointer dereference if DT failed to provide a host bridge
memory window (Aleksandr Mishin)
* pci/controller/keystone:
PCI: keystone: Add workaround for Errata #i2037 (AM65x SR 1.0)
PCI: keystone: Fix NULL pointer dereference in case of DT error in ks_pcie_setup_rc_app_regs()
PCI: keystone: Don't enable BAR 0 for AM654x
PCI: keystone: Relocate ks_pcie_set/clear_dbi_mode()
- Correct the dra7xx_pcie_cpu_addr_fixup() parameter name, which takes a
CPU address but called it "pci_addr" (Niklas Cassel)
* pci/controller/dra7xx:
PCI: dra7xx: Fix dra7xx_pcie_cpu_addr_fixup() parameter name
- Correct the artpec6_pcie_cpu_addr_fixup() parameter name, which takes a
CPU address but called it "pci_addr" (Niklas Cassel)
* pci/controller/artpec6:
PCI: artpec6: Fix artpec6_pcie_cpu_addr_fixup() parameter name
- Check IORESOURCE_BUS existence to avoid NULL pointer dereference
(Aleksandr Mishin)
* pci/controller/al:
PCI: al: Check IORESOURCE_BUS existence during probe
- Use msleep() in DWC core instead of usleep_range() for ~100 ms sleep
(Konrad Dybcio)
- Fix iATU slot management to avoid using the wrong slot after PERST#
assert/deassert, which could potentially cause DMA to go the wrong place
(Frank Li)
- Consolidate dw_pcie_prog_outbound_atu() arguments into a struct to ease
adding new functionality like initiating Message TLPs (Yoshihiro Shimoda)
- Add support for endpoints to initiate PCIe messages (Yoshihiro Shimoda)
- Add #defines for PCIe INTx messages (Yoshihiro Shimoda)
- Add support for endpoints to initiate PCIe PME_Turn_Off messages for
system suspend (Frank Li)
- Add dw_pcie_ep_linkdown() to reinitialize registers that are lost when
the link goes down (Manivannan Sadhasivam)
- Use dw_pcie_ep_linkdown() to reinitialize qcom non-sticky registers that
are lost when the link goes down (Manivannan Sadhasivam)
- Enforce DWC limitation that 64-bit BARs must start with the even numbered
BAR (Niklas Cassel)
* pci/controller/dwc:
PCI: dwc: ep: Enforce DWC specific 64-bit BAR limitation
PCI: layerscape-ep: Use the generic dw_pcie_ep_linkdown() API to handle Link Down event
PCI: qcom-ep: Use the generic dw_pcie_ep_linkdown() API to handle Link Down event
PCI: dwc: ep: Remove dw_pcie_ep_init_notify() wrapper
PCI: dwc: ep: Add a generic dw_pcie_ep_linkdown() API to handle Link Down event
PCI: dwc: Add generic MSG TLP support for sending PME_Turn_Off when system suspend
PCI: Add PCIE_MSG_CODE_PME_TURN_OFF message macro
PCI: Add PCIE_MSG_CODE_ASSERT_INTx message macros
PCI: dwc: Add outbound MSG TLPs support
PCI: dwc: Consolidate args of dw_pcie_prog_outbound_atu() into a structure
PCI: dwc: Fix index 0 incorrectly being interpreted as a free ATU slot
PCI: dwc: Use msleep() in dw_pcie_wait_for_link()
- Include <linux/irqchip/chained_irq.h> in dra7xx to avoid implicitly
including it elsewhere (Andy Shevchenko)
- Remove unused <linux/of_gpio.h> from aardvark and dwc drivers (dra7xx,
meson, qcom, tegra194) (Andy Shevchenko)
- Convert kirin to use scoped for_each_available_child_of_node() to ease
future error exits (Javier Carrasco)
- Convert imx6 and kirin to use the agnostic GPIO API to simplify GPIO
setup and remove usage of the deprecated of_gpio.h API (Andy Shevchenko)
* pci/controller/gpio:
PCI: kirin: Convert to use agnostic GPIO API
PCI: kirin: Convert kirin_pcie_parse_port() to scoped iterator
PCI: imx6: Convert to use agnostic GPIO API
PCI: dwc: Remove unused of_gpio.h inclusion
PCI: aardvark: Remove unused of_gpio.h inclusion
PCI: dra7xx: Add missing chained IRQ header inclusion
Smatch complains that "ret" could be uninitialized if "pcie->icc_mem" is
NULL and "pm_suspend_target_state == PM_SUSPEND_MEM".
Silence this warning by initializing ret to zero.
Fixes: 78b5f6f8855e ("PCI: qcom: Add OPP support to scale performance")
Link: https://lore.kernel.org/linux-pci/20240708180539.1447307-4-dan.carpenter@linaro.org
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Only call dev_pm_opp_put() if dev_pm_opp_find_freq_exact() succeeds;
otherwise it leads to an error pointer dereference.
Fixes: 78b5f6f8855e ("PCI: qcom: Add OPP support to scale performance")
Link: https://lore.kernel.org/linux-pci/20240708180539.1447307-3-dan.carpenter@linaro.org
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
A previous commit ("PCI: dwc: ep: Remove dw_pcie_ep_init_notify() wrapper")
removed the dw_pcie_ep_init_notify() wrapper and changed the DWC glue
drivers to instead use pci_epc_init_notify() directly.
The endpoint support for the dw-rockchip had not been merged at that point
in time, so the previous commit wrapper") did not update dw-rockchip.
Do the same change for dw-rockchip, so that the driver will not try
to use a function that has now been removed.
Link: https://lore.kernel.org/linux-pci/20240622132024.2927799-2-cassel@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The PCIe controller in rk3568 and rk3588 can operate in endpoint mode.
This endpoint mode support heavily leverages the existing code in
pcie-designware-ep.c.
Add support for endpoint mode to the existing pcie-dw-rockchip glue
driver.
[kwilczynski: squash with patch adding the PCI_ENDPOINT dependency]
Link: https://lore.kernel.org/linux-pci/20240607-rockchip-pcie-ep-v1-v5-10-0a042d6b0049@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Refactor the driver to prepare for EP mode.
Add of-match data to the existing compatible, and explicitly define it as
DW_PCIE_RC_TYPE. This way, we will be able to add EP mode in a follow-up
commit in a much less intrusive way, which makes the follow-up commit much
easier to review.
No functional change intended.
Link: https://lore.kernel.org/linux-pci/20240607-rockchip-pcie-ep-v1-v5-9-0a042d6b0049@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Add a rockchip_pcie_ltssm() helper function that reads the LTSSM status.
This helper will be used in additional places in follow-up commits.
Link: https://lore.kernel.org/linux-pci/20240607-rockchip-pcie-ep-v1-v5-8-0a042d6b0049@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Fix the indentation of rockchip_pcie_{readl,writel}_apb() parameters to
match the opening parenthesis.
Link: https://lore.kernel.org/linux-pci/20240607-rockchip-pcie-ep-v1-v5-7-0a042d6b0049@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
PERST# is active low according to the PCIe specification.
However, the existing pcie-dw-rockchip.c driver does:
gpiod_set_value(..., 0); msleep(100); gpiod_set_value(..., 1);
when asserting + deasserting PERST#.
This is of course wrong, but because all the device trees for this
compatible string have also incorrectly marked this GPIO as ACTIVE_HIGH:
$ git grep -B 10 reset-gpios arch/arm64/boot/dts/rockchip/rk3568*
$ git grep -B 10 reset-gpios arch/arm64/boot/dts/rockchip/rk3588*
The actual toggling of PERST# is correct, and we cannot change it anyway,
since that would break device tree compatibility.
However, this driver does request the GPIO to be initialized as
GPIOD_OUT_HIGH, which does cause a silly sequence where PERST# gets
toggled back and forth for no good reason.
Fix this by requesting the GPIO to be initialized as GPIOD_OUT_LOW (which
for this driver means PERST# asserted).
This will avoid an unnecessary signal change where PERST# gets deasserted
(by devm_gpiod_get_optional()) and then gets asserted (by
rockchip_pcie_start_link()) just a few instructions later.
Before patch, debug prints on EP side, when booting RC:
[ 845.606810] pci: PERST# asserted by host!
[ 852.483985] pci: PERST# de-asserted by host!
[ 852.503041] pci: PERST# asserted by host!
[ 852.610318] pci: PERST# de-asserted by host!
After patch, debug prints on EP side, when booting RC:
[ 125.107921] pci: PERST# asserted by host!
[ 132.111429] pci: PERST# de-asserted by host!
This extra, very short, PERST# assertion + deassertion has been reported to
cause issues with certain WLAN controllers, e.g. RTL8822CE.
Fixes: 0e898eb8df ("PCI: rockchip-dwc: Add Rockchip RK356X host controller driver")
Link: https://lore.kernel.org/linux-pci/20240417164227.398901-1-cassel@kernel.org
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Jianfeng Liu <liujianfeng1994@gmail.com>
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: stable@vger.kernel.org # v5.15+
Drivers that silently fail to probe provide a bad user experience and
make it unnecessarily hard to debug such a failure.
Fix it by using dev_err_probe() instead of a plain return.
[kwilczynski: commit log]
Link: https://lore.kernel.org/linux-pci/20240227141256.413055-2-ukleinek@debian.org
Signed-off-by: Uwe Kleine-König <ukleinek@debian.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Jesper Nilsson <jesper.nilsson@axis.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
From the DWC EP databook 5.96a, section "3.5.7.1.4 General Rules for BAR
Setup (Fixed Mask or Programmable Mask Schemes Only)":
"Any pair (for example BARs 0 and 1) can be configured as one 64-bit BAR,
two 32-bit BARs, or one 32-bit BAR."
"BAR pairs cannot overlap to form a 64-bit BAR. For example, you cannot
combine BARs 1 and 2 to form a 64-bit BAR."
While this limitation does exist in some other PCI endpoint controllers,
e.g. cdns_pcie_ep_set_bar(), the limitation does not appear to be defined
in the PCIe specification itself, thus add an explicit check for this in
dw_pcie_ep_set_bar() (rather than pci_epc_set_bar()).
Link: https://lore.kernel.org/linux-pci/20240528134839.8817-2-cassel@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Now that dw_pcie_ep_linkdown() is available, use it. This also handles the
reinitialization of DWC non-sticky registers in addition to sending the
notification to EPF drivers.
Closes: https://lore.kernel.org/linux-pci/20240528195539.GA458945@bhelgaas
Link: https://lore.kernel.org/linux-pci/20240606-pci-deinit-v1-5-4395534520dc@linaro.org
Reported-by: Bjorn Helgaas <helgaas@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Now that the generic dw_pcie_ep_linkdown() API is available, use it. This
also handles the reinitialization of DWC non-sticky registers in addition
to sending the notification to EPF drivers.
Link: https://lore.kernel.org/linux-pci/20240430-pci-epf-rework-v4-9-22832d0d456f@linaro.org
Tested-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Currently dw_pcie_ep_init_notify() wrapper just calls pci_epc_init_notify()
directly, so this wrapper provides no benefit to the glue drivers.
Remove it and call pci_epc_init_notify() directly from glue drivers.
Suggested-by: Bjorn Helgaas <helgaas@kernel.org>
Link: https://lore.kernel.org/linux-pci/20240606-pci-deinit-v1-1-4395534520dc@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Per PCIe r6.0, sec 5.2, a Link Down event can happen under any of the
following circumstances:
1. Fundamental/Hot reset
2. Link disable transmission by upstream component
3. Moving from L2/L3 to L0
In those cases, Link Down causes some non-sticky DWC registers to lose the
state (like REBAR, etc.), so drivers need to reinitialize them to function
properly once the link comes back again.
This is not a problem for drivers supporting PERST# IRQ, since they can
reinitialize the registers in the PERST# IRQ callback. But for the drivers
not supporting PERST#, there is no way they can reinitialize the registers
other than relying on Link Down IRQ received when the link goes down. So
add a DWC generic API dw_pcie_ep_linkdown() that reinitializes the
non-sticky registers and also notifies the EPF drivers about link going
down.
This API can also be used by the drivers supporting PERST# to handle the
scenario (2) mentioned above.
NOTE: For the sake of code organization, move the dw_pcie_ep_linkup()
definition just above dw_pcie_ep_linkdown().
Link: https://lore.kernel.org/linux-pci/20240430-pci-epf-rework-v4-8-22832d0d456f@linaro.org
Tested-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
[bhelgaas: update spec citation]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Instead of relying on the vendor specific implementations to send the
PME_Turn_Off message, introduce a generic way of sending the message using
the MSG TLP.
This is achieved by reserving a region for MSG TLP of size
'pci->region_align', at the end of the first IORESOURCE_MEM window of the
host bridge. And then sending the PME_Turn_Off message during system
suspend with the help of iATU.
The reason for reserving the MSG TLP region at the end of the
IORESOURCE_MEM is to avoid generating holes in between, because when the
region is allocated using allocate_resource(), memory will be allocated
from the start of the window. Later, if memory gets allocated for an
endpoint of size bigger than 'region_align', there will be a hole between
MSG TLP region and endpoint memory.
This generic implementation is optional for the glue drivers and can be
overridden by a custom 'pme_turn_off' callback.
Link: https://lore.kernel.org/linux-pci/20240418-pme_msg-v8-5-a54265c39742@nxp.com
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Add "code" and "routing" into struct dw_pcie_ob_atu_cfg for triggering
INTx IRQs by iATU in the PCIe endpoint mode in near the future.
PCIE_ATU_INHIBIT_PAYLOAD is set to issue TLP type of Msg instead of
MsgD. This implementation supports the data-less messages only for now.
Link: https://lore.kernel.org/linux-pci/20240418-pme_msg-v8-3-a54265c39742@nxp.com
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
This is a preparation before adding the Msg-type outbound iATU
mapping. The respective update will require two more arguments added
to __dw_pcie_prog_outbound_atu(). That will make the already
complicated function prototype even more hard to comprehend accepting
_eight_ arguments.
To prevent that and keep the code more-or-less readable, move all the
outbound iATU-related arguments to a new config structure: struct
dw_pcie_ob_atu_cfg, and pass a pointer to dw_pcie_prog_outbound_atu(). The
structure should be locally defined and populated with the outbound iATU
settings implied by the caller context.
As a result of this change there is no longer need in having the two
distinctive methods for the Host and Endpoint outbound iATU setups since
the code can directly call the dw_pcie_prog_outbound_atu() method with the
config structure populated, so drop dw_pcie_prog_ep_outbound_atu().
[kwilczynski: commit log]
Link: https://lore.kernel.org/linux-pci/20240418-pme_msg-v8-2-a54265c39742@nxp.com
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
When PERST# assert and deassert happens on the PERST# supported platforms,
both iATU0 and iATU6 will map inbound window to BAR0. DMA will access the
area that was previously allocated (iATU0) for BAR0, instead of the new
area (iATU6) for BAR0.
Right now, this isn't an issue because both iATU0 and iATU6 should
translate inbound accesses to BAR0 to the same allocated memory area.
However, having two separate inbound mappings for the same BAR is a
disaster waiting to happen.
The mappings between PCI BAR and iATU inbound window are maintained in the
dw_pcie_ep::bar_to_atu[] array. While allocating a new inbound iATU map for
a BAR, dw_pcie_ep_inbound_atu() API checks for the availability of the
existing mapping in the array and if it is not found (i.e., value in the
array indexed by the BAR is found to be 0), it allocates a new map value
using find_first_zero_bit().
The issue is the existing logic failed to consider the fact that the map
value '0' is a valid value for BAR0, so find_first_zero_bit() will return
'0' as the map value for BAR0 (note that it returns the first zero bit
position).
Due to this, when PERST# assert + deassert happens on the PERST# supported
platforms, the inbound window allocation restarts from BAR0 and the
existing logic to find the BAR mapping will return '6' for BAR0 instead of
'0' due to the fact that it considers '0' as an invalid map value.
Fix this issue by always incrementing the map value before assigning to
bar_to_atu[] array and then decrementing it while fetching. This will make
sure that the map value '0' always represents the invalid mapping."
Fixes: 4284c88fff ("PCI: designware-ep: Allow pci_epc_set_bar() update inbound map address")
Closes: https://lore.kernel.org/linux-pci/ZXsRp+Lzg3x%2Fnhk3@x1-carbon/
Link: https://lore.kernel.org/linux-pci/20240412160841.925927-1-Frank.Li@nxp.com
Reported-by: Niklas Cassel <Niklas.Cassel@wdc.com>
Tested-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
According to [1], msleep should be used for large sleeps, such as the
100-ish ms one in this function. Comply with the guide and use it.
[1] https://docs.kernel.org/timers/timers-howto.html
[kwilczynski: commit log]
Link: https://lore.kernel.org/linux-pci/20240215-topic-pci_sleep-v2-1-79334884546b@linaro.org
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
The of_gpio.h legacy API is going to be removed. In preparation for that,
convert the driver to the agnostic API.
[kwilczynski: commit log]
Link: https://lore.kernel.org/linux-pci/20240506142142.4042810-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Convert loops in kirin_pcie_parse_port() to use the _scoped() version of
for_each_available_child_of_node() so the refcounts of children are
implicitly decremented when the loop is exited.
No functional change intended here, but it will make future error exits
from these loops easier.
Link: https://lore.kernel.org/linux-pci/20240609-pcie-kirin-memleak-v1-1-62b45b879576@gmail.com
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
[bhelgaas: move to GPIO series to avoid bisection hole, commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
QCOM Resource Power Manager-hardened (RPMh) is a hardware block which
maintains hardware state of a regulator by performing max aggregation of
the requests made by all of the clients.
PCIe controller can operate on different RPMh performance state of power
domain based on the speed of the link. And this performance state varies
from target to target, like some controllers support GEN3 in NOM (Nominal)
voltage corner, while some other supports GEN3 in low SVS (static voltage
scaling).
The SoC can be more power efficient if we scale the performance state
based on the aggregate PCIe link bandwidth.
Add Operating Performance Points (OPP) support to vote for RPMh state based
on the aggregate link bandwidth.
OPP can handle ICC bw voting also, so move ICC bw voting through OPP
framework if OPP entries are present.
As we are moving ICC voting as part of OPP, don't initialize ICC if OPP
is supported.
Before PCIe link is initialized vote for highest OPP in the OPP table,
so that we are voting for maximum voltage corner for the link to come up
in maximum supported speed.
Link: https://lore.kernel.org/linux-pci/20240619-opp_support-v15-4-aa769a2173a3@quicinc.com
Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
[bhelgaas: wrap comments to fit in 80 columns]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
To access the host controller registers of the host controller and the
endpoint BAR/config space, the CPU-PCIe ICC (interconnect) path should
be voted otherwise it may lead to NoC (Network on chip) timeout.
We are surviving because of other driver voting for this path.
As there is less access on this path compared to PCIe to mem path
add minimum vote i.e 1KBps bandwidth always which is sufficient enough
to keep the path active and is recommended by HW team.
During S2RAM (Suspend-to-RAM), the DBI access can happen very late (while
disabling the boot CPU). So do not disable the CPU-PCIe interconnect path
during S2RAM as that may lead to NoC error.
Link: https://lore.kernel.org/linux-pci/20240619-opp_support-v15-1-aa769a2173a3@quicinc.com
Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
All EP specific resources are enabled during PERST# deassert. As a counter
operation, all resources should be disabled during PERST# assert. There is
no point in skipping that if the link was not enabled.
This will also result in enablement of the resources twice if PERST# got
deasserted again. So remove the check from qcom_pcie_perst_assert() and
disable all the resources unconditionally.
Fixes: f55fee56a6 ("PCI: qcom-ep: Add Qualcomm PCIe Endpoint controller driver")
Link: https://lore.kernel.org/linux-pci/20240430-pci-epf-rework-v4-1-22832d0d456f@linaro.org
Tested-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Due to some hardware changes, SA8775P has set the NO_SNOOP attribute
in its TLP for all the PCIe controllers. NO_SNOOP attribute when set,
the requester is indicating that no cache coherency issues exist for
the addressed memory on the host i.e., memory is not cached. But in
reality, requester cannot assume this unless there is a complete
control/visibility over the addressed memory on the host.
And worst case, if the memory is cached on the host, it may lead to
memory corruption issues. It should be noted that the caching of memory
on the host is not solely dependent on the NO_SNOOP attribute in TLP.
So to avoid the corruption, this patch overrides the NO_SNOOP attribute
by setting the PCIE_PARF_NO_SNOOP_OVERIDE register. This patch is not
needed for other upstream supported platforms since they do not set
NO_SNOOP attribute by default.
Link: https://lore.kernel.org/linux-pci/1710166298-27144-3-git-send-email-quic_msarkar@quicinc.com
Signed-off-by: Mrinmay Sarkar <quic_msarkar@quicinc.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Due to some hardware changes, SA8775P has set the NO_SNOOP attribute
in its TLP for all the PCIe controllers. NO_SNOOP attribute when set,
the requester is indicating that no cache coherency issue exist for
the addressed memory on the endpoint i.e., memory is not cached. But
in reality, requester cannot assume this unless there is a complete
control/visibility over the addressed memory on the endpoint.
And worst case, if the memory is cached on the endpoint, it may lead to
memory corruption issues. It should be noted that the caching of memory
on the endpoint is not solely dependent on the NO_SNOOP attribute in TLP.
So to avoid the corruption, this patch overrides the NO_SNOOP attribute
by setting the PCIE_PARF_NO_SNOOP_OVERIDE register. This patch is not
needed for other upstream supported platforms since they do not set
NO_SNOOP attribute by default.
8775 has IP version 1.34.0 so introduce a new cfg(cfg_1_34_0) for this
platform. Assign override_no_snoop flag into struct qcom_pcie_cfg and
set it true in cfg_1_34_0 and enable cache snooping if this particular
flag is true.
Link: https://lore.kernel.org/linux-pci/1710166298-27144-2-git-send-email-quic_msarkar@quicinc.com
Signed-off-by: Mrinmay Sarkar <quic_msarkar@quicinc.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
[bhelgaas: wrap comments to fit in 80 columns]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
