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path: root/drivers/cxl/core/pci.c
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2026-10-09cxl: Account for link width in latency calculationKoichiro Den
cxl_pci_get_latency() derives bandwidth from the per-lane speed returned by pcie_link_speed_mbps(), ignoring the negotiated link width. This overestimates the FlitLatency contribution for multi-lane links. Sections 2.11.3 and 2.11.4 of the Intel CXL Memory Device Software Guide describe the link bandwidth as the product of the negotiated speed and width. Replace pcie_link_speed_mbps() with pcie_link_bandwidth_mbps() and migrate both CXL callers (the only users of the API). The new helper obtains speed and width from a single Link Status read. The CXL bandwidth calculation no longer needs a separate width read and multiplication. While at it, make error handling more robust by converting PCI config read errors to negative errno values and checking for zero bandwidth before calculating latency. Fixes: 4d07a05397c8 ("cxl: Calculate and store PCI link latency for the downstream ports") Cc: stable@vger.kernel.org Signed-off-by: Koichiro Den <den@valinux.co.jp> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> # pci/pci.c Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://patch.msgid.link/20261009045452.1107921-3-den@valinux.co.jp Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-10-09cxl/pci: Update only the Port GPF timeout fieldsGuixin Liu
update_gpf_port_dvsec() rebuilds the phase control register from just the timeout base and scale, so the rest of the register is cleared by the write. The other bits are reserved today and nothing is lost, but the full-register rewrite would clobber any field the spec defines there later. Read-modify-write the register and change only the two timeout fields. Fixes: a52b6a2c1c99 ("cxl/pci: Support Global Persistent Flush (GPF)") Assisted-by: LLM Signed-off-by: Guixin Liu <kanie@linux.alibaba.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Link: https://patch.msgid.link/20261008034619.28059-4-kanie@linux.alibaba.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-10-09cxl/pci: Program the Port GPF timeouts before caching the DVSECGuixin Liu
cxl_gpf_port_setup() caches the Port GPF DVSEC offset in the dport before programming the phase timeouts, and ignores the return value of both update_gpf_port_dvsec() calls: the function always reports success. A failing config write is therefore not only silent, it is also permanent: the timeouts stay at the hardware defaults instead of the maximum flush window the kernel is asking for, and the cached offset keeps any later endpoint attach from retrying the update. Propagate the errors and cache the offset only after both phases are programmed, so the next endpoint attach retries the setup. Fixes: 6af941db6a60 ("cxl/pci: Update Port GPF timeout only when the first EP attaching") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Guixin Liu <kanie@linux.alibaba.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Link: https://patch.msgid.link/20261008034619.28059-3-kanie@linux.alibaba.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-10-09cxl/pci: Use the Device GPF DVSEC for restricted endpointsGuixin Liu
cxl_gpf_get_dvsec() picks between the Port and the Device GPF DVSEC from the PCIe type of the given device, and only a plain endpoint counts as a device. A restricted CXL device is an endpoint too, but it falls into the port case and is probed for the Port GPF DVSEC instead of the Device GPF DVSEC. On an RCD, dirty shutdown tracking therefore never arms: the DVSEC lookup in cxl_nvdimm_arm_dirty_shutdown_tracking() fails, the dirty shutdown count stays invalid, and the warning complains about a missing Port GPF DVSEC on a device. Treat restricted endpoints as devices. Fixes: 36aace15d9bd ("cxl/pci: Drop the parameter is_port of cxl_gpf_get_dvsec()") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Guixin Liu <kanie@linux.alibaba.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Link: https://patch.msgid.link/20261008034619.28059-2-kanie@linux.alibaba.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-10-09cxl/core: Hold the dport host lock across dport lookup and useDave Jiang
Callers of cxl_pci_find_port() and cxl_mem_find_port() can be handed a 'struct cxl_dport' that is already freed, and all four dereference it without the lock that would prevent that. A dport is kzalloc()'d into a devres group on its host device, so it dies when that host unbinds. The host is &port->dev for a switch port and port->uport_dev for the root port. Both helpers return the dport through an output parameter. The caller's port reference pins struct cxl_port, not the dport allocation, and the lookup itself is a bare xa_load() under no lock. Add cxl_port_dport_host() to name the device that pins a dport, and cxl_pci_find_dport() / cxl_mem_find_dport() to look one up with that device's lock held and asserted. Convert the four callers to use them and bail if the dport is gone. cxl_port_add_dport() already follows this rule. cxl_mem_probe() chose its endpoint devm host from dport->rch, which meant dereferencing the dport before taking any lock. Use cxl_port_dport_host(): rch dports only ever land on the root port, so it selects the same device without needing the dport. With every caller converted, the dport output parameter of cxl_pci_find_port() and cxl_mem_find_port() is unused. Drop it. Fixes: 733b57f262b0 ("cxl/pci: Early setup RCH dport component registers from RCRB") Assisted-by: LLM Reviewed-by: Li Ming <ming.li@zohomail.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Link: https://patch.msgid.link/20261001154744.1095902-3-dave.jiang@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-09-17cxl/pci: Skip reset detection for DVSEC emulated decodersGuixin Liu
HDM decoders are emulated from the DVSEC range registers in two cases: (a) the component registers expose no HDM decoder capability, or (b) the capability is present but the DVSEC ranges were the ones in use at driver load. After an FLR or SBR, __cxl_endpoint_decoder_reset_detected() reads the HDM decoder Committed bit for every decoder marked enabled, emulated ones included. In case (a) regs.hdm_decoder is NULL and the read oopses. In case (b) the Committed bit was never set, so a reset gets reported that never happened. Use the absence of cxld->commit to elide the check for emulated decoders. Case (b) tested under QEMU: a reset on an endpoint driven down the DVSEC emulation path no longer reports a reset or strips the decoder flags. Fixes: 934edcd436dc ("cxl: Add post-reset warning if reset results in loss of previously committed HDM decoders") Signed-off-by: Guixin Liu <kanie@linux.alibaba.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com> Link: https://lore.kernel.org/linux-cxl/20260811113608.2815625-1-kanie@linux.alibaba.com/ Link: https://patch.msgid.link/20260831110449.719086-1-kanie@linux.alibaba.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-06-29cxl: Support Type2 cxl regs mappingAlejandro Lucero
Export cxl core functions for a Type2 driver being able to discover and map the device registers. Signed-off-by: Alejandro Lucero <alucerop@amd.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Ben Cheatham <benjamin.cheatham@amd.com> Acked-by: Edward Cree <ecree.xilinx@gmail.com> Link: https://patch.msgid.link/20260629183727.51502-2-alejandro.lucero-palau@amd.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-06-04cxl/pci: Convert PCIBIOS errors to errno on DVSEC config accessesDave Jiang
PCI config space accessors return positive PCIBIOS_* status codes on failure that are positive integers. Several DVSEC accesses in the CXL core propagated these raw values to callers that test for failure against less than 0. Thus silently misinterpret the return value as success. Convert the positive error values to negative errno values so the checks are correct on error paths. While the chances of a config access failure are low, fix for correctness and to avoid confusion in the future when more DVSEC accesses are added. Fixes: 14d788740774 ("cxl/mem: Consolidate CXL DVSEC Range enumeration in the core") Fixes: ce17ad0d5498 ("cxl: Wait Memory_Info_Valid before access memory related info") Reviewed-by: Richard Cheng <icheng@nvidia.com> Reviewed-by: Jonathan Cameron <jic23@kernel.org> Assisted-by: Claude:claude-opus-4-8 Reviewed-by: Alison Schofield <alison.schofield@intel.com> Link: https://patch.msgid.link/20260604180154.1925149-3-dave.jiang@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-06-04cxl/pci: Fix the incorrect check of pci_read_config_word() returnDave Jiang
pci_read_config_word() returns PCIBIOS_* status on error which are positive values. The check should be for non-zero values to indicate error. Fix cxl_set_mem_enable() to check for non-zero return value instead of negative value. While fixing this, also convert the error to negative errno value when returning on error path. Fixes: 34e37b4c432c ("cxl/port: Enable HDM Capability after validating DVSEC Ranges") Reviewed-by: Richard Cheng <icheng@nvidia.com> Reviewed-by: Jonathan Cameron <jic23@kernel.org> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Assisted-by: Claude:claude-opus-4-8 Link: https://patch.msgid.link/20260604180154.1925149-2-dave.jiang@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-03-16cxl/pci: Remove redundant cxl_pci_find_port() callGregory Price
Remove the redundant port lookup from cxl_rcrb_get_comp_regs() and use the dport parameter directly. The caller has already validated the port is non-NULL before invoking this function, and dport is given as a param. This is simpler than getting dport in the callee and return the pointer to the caller what would require more changes. Signed-off-by: Gregory Price <gourry@gourry.net> Reviewed-by: Alejandro Lucero <alucerop@amd.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Link: https://patch.msgid.link/20260306164741.3796372-5-alejandro.lucero-palau@amd.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-03-16cxl: Move pci generic code from cxl_pci to core/cxl_pciAlejandro Lucero
Inside cxl/core/pci.c there are helpers for CXL PCIe initialization meanwhile cxl/pci_drv.c implements the functionality for a Type3 device initialization. In preparation for type2 support, move helper functions from cxl/pci.c to cxl/core/pci.c in order to be exported and used by type2 drivers. [ dj: Clarified subject. ] Signed-off-by: Alejandro Lucero <alucerop@amd.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Gregory Price <gourry@gourry.net> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Signed-off-by: Gregory Price <gourry@gourry.net> Link: https://patch.msgid.link/20260306164741.3796372-4-alejandro.lucero-palau@amd.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-02-02cxl/port: Move dport probe operations to a driver eventDan Williams
In preparation for adding more register setup to the cxl_port_add_dport() path (for RAS register mapping), move the dport creation event to a driver callback. This achieves two goals, it puts driver operations logically where they belong, in a driver, and it obviates the gymnastics of DECLARE_TESTABLE() which just makes a mess of grepping for CXL symbols. In other words, a driver callback is less of an ongoing maintenance burden than this DECLARE_TESTABLE arrangement that does not scale and diminishes the grep-ability of the codebase. cxl_port_add_dport() moves mostly unmodified from drivers/cxl/core/port.c. The only deliberate change is that it now assumes that the device_lock is held on entry and the driver is attached (just like cxl_port_probe()). Reviewed-by: Terry Bowman <terry.bowman@amd.com> Tested-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Link: https://patch.msgid.link/20260131000403.2135324-6-dan.j.williams@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-01-22cxl/pci: Move CXL driver's RCH error handling into core/ras_rch.cTerry Bowman
Restricted CXL Host (RCH) protocol error handling uses a procedure distinct from the CXL Virtual Hierarchy (VH) handling. This is because of the differences in the RCH and VH topologies. Improve the maintainability and add ability to enable/disable RCH handling. Move and combine the RCH handling code into a single block conditionally compiled with the CONFIG_CXL_RCH_RAS kernel config. Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://patch.msgid.link/20260114182055.46029-9-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-01-22cxl/pci: Remove CXL VH handling in CONFIG_PCIEAER_CXL conditional blocks ↵Dave Jiang
from core/pci.c Create new config CONFIG_CXL_RAS and put all CXL RAS items behind the config. The config will depend on CPER and PCIE AER to build. Move the related VH RAS code from core/pci.c to core/ras.c. Restricted CXL host (RCH) RAS functions will be moved in a future patch. Cc: Robert Richter <rrichter@amd.com> Reviewed-by: Joshua Hahn <joshua.hahnjy@gmail.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Co-developed-by: Terry Bowman <terry.bowman@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://patch.msgid.link/20260114182055.46029-8-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-01-22cxl/pci: Remove unnecessary CXL RCH handling helper functionsTerry Bowman
cxl_handle_rdport_cor_ras() and cxl_handle_rdport_ras() are specific to Restricted CXL Host (RCH) handling. Improve readability and maintainability by replacing these and instead using the common cxl_handle_cor_ras() and cxl_handle_ras() functions. Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Alejandro Lucero <alucerop@amd.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://patch.msgid.link/20260114182055.46029-6-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-01-22cxl/pci: Remove unnecessary CXL Endpoint handling helper functionsTerry Bowman
The CXL driver's cxl_handle_endpoint_cor_ras()/cxl_handle_endpoint_ras() are unnecessary helper functions used only for Endpoints. Remove these functions as they are not common for all CXL devices and do not provide value for EP handling. Rename __cxl_handle_ras to cxl_handle_ras() and __cxl_handle_cor_ras() to cxl_handle_cor_ras(). Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Tested-by: Joshua Hahn <joshua.hahnjy@gmail.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://patch.msgid.link/20260114182055.46029-5-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-01-22PCI: Update CXL DVSEC definitionsTerry Bowman
CXL DVSEC definitions were recently moved into uapi/pci_regs.h, but the newly added macros do not follow the file's existing naming conventions. The current format uses CXL_DVSEC_XYZ, while the new CXL entries must instead use the PCI_DVSEC_CXL_XYZ prefix to match the conventions already established in pci_regs.h. The new CXL DVSEC macros also introduce _MASK and _OFFSET suffixes, which are not used anywhere else in the file. These suffixes lengthen the identifiers and reduce readability. Remove _MASK and _OFFSET from the recently added definitions. Additionally, remove PCI_DVSEC_HEADER1_LENGTH, as it duplicates the existing PCI_DVSEC_HEADER1_LEN() macro. Update all existing references to use the new macro names. Finally, update the inline documentation to reference the latest revision of the CXL specification. Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20260114182055.46029-3-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2025-11-03cxl/port: Remove devm_cxl_port_enumerate_dports()Li Ming
devm_cxl_port_enumerate_dports() is not longer used after below commit commit 4f06d81e7c6a ("cxl: Defer dport allocation for switch ports") Delete it and the relevant interface implemented in cxl_test. Signed-off-by: Li Ming <ming.li@zohomail.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2025-09-18cxl/test: Add mock version of devm_cxl_add_dport_by_dev()Dave Jiang
devm_cxl_add_dport_by_dev() outside of cxl_test is done through PCI hierarchy. However with cxl_test, it needs to be done through the platform device hierarchy. Add the mock function for devm_cxl_add_dport_by_dev(). When cxl_core calls a cxl_core exported function and that function is mocked by cxl_test, the call chain causes a circular dependency issue. Dan provided a workaround to avoid this issue. Apply the method to changes from the late dport allocation changes in order to enable cxl-test. In cxl_core they are defined with "__" added in front of the function. A macro is used to define the original function names for when non-test version of the kernel is built. A bit of macros and typedefs are used to allow mocking of those functions in cxl_test. Co-developed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Li Ming <ming.li@zohomail.com> Tested-by: Alison Schofield <alison.schofield@intel.com> Tested-by: Robert Richter <rrichter@amd.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2025-09-18cxl: Defer dport allocation for switch portsDave Jiang
The current implementation enumerates the dports during the cxl_port driver probe. Without an endpoint connected, the dport may not be active during port probe. This scheme may prevent a valid hardware dport id to be retrieved and MMIO registers to be read when an endpoint is hot-plugged. Move the dport allocation and setup to behind memdev probe so the endpoint is guaranteed to be connected. In the original enumeration behavior, there are 3 phases (or 2 if no CXL switches) for port creation. cxl_acpi() creates a Root Port (RP) from the ACPI0017.N device. Through that it enumerates downstream ports composed of ACPI0016.N devices through add_host_bridge_dport(). Once done, it uses add_host_bridge_uport() to create the ports that enumerate the PCI RPs as the dports of these ports. Every time a port is created, the port driver is attached, cxl_switch_porbe_probe() is called and devm_cxl_port_enumerate_dports() is invoked to enumerate and probe the dports. The second phase is if there are any CXL switches. When the pci endpoint device driver (cxl_pci) calls probe, it will add a mem device and triggers the cxl_mem_probe(). cxl_mem_probe() calls devm_cxl_enumerate_ports() and attempts to discovery and create all the ports represent CXL switches. During this phase, a port is created per switch and the attached dports are also enumerated and probed. The last phase is creating endpoint port which happens for all endpoint devices. The new sequence is instead of creating all possible dports at initial port creation, defer port instantiation until a memdev beneath that dport arrives. Introduce devm_cxl_create_or_extend_port() to centralize the creation and extension of ports with new dports as memory devices arrive. As part of this rework, switch decoder target list is amended at runtime as dports show up. While the decoders are allocated during the port driver probe, The decoders must also be updated since previously they were setup when all the dports are setup. Now every time a dport is setup per endpoint, the switch target listing need to be updated with new dport. A guard(rwsem_write) is used to update decoder targets. This is similar to when decoder_populate_target() is called and the decoder programming must be protected. Also the port registers are probed the first time when the first dport shows up. This ensures that the CXL link is established when the port registers are probed. [dj] Use ERR_CAST() (Jonathan) Link: https://lore.kernel.org/linux-cxl/20250305100123.3077031-1-rrichter@amd.com/ Reviewed-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2025-09-18cxl/test: Refactor decoder setup to reduce cxl_test burdenDave Jiang
Group the decoder setup code in switch and endpoint port probe into a single function for each to reduce the number of functions to be mocked in cxl_test. Introduce devm_cxl_switch_port_decoders_setup() and devm_cxl_endpoint_decoders_setup(). These two functions will be mocked instead with some functions optimized out since the mock version does not do anything. Remove devm_cxl_setup_hdm(), devm_cxl_add_passthrough_decoder(), and devm_cxl_enumerate_decoders() in cxl_test mock code. In turn, mock_cxl_add_passthrough_decoder() can be removed since cxl_test does not setup passthrough decoders. __wrap_cxl_hdm_decode_init() and __wrap_cxl_dvsec_rr_decode() can be removed as well since they only return 0 when called. [dj: drop 'struct cxl_port' forward declaration (Robert)] Suggested-by: Robert Richter <rrichter@amd.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Robert Richter <rrichter@amd.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2025-05-09cxl/pci: Add comments to cxl_hdm_decode_init()Robert Richter
There are various configuration cases of HDM decoder registers causing different code paths. Add comments to cxl_hdm_decode_init() to better explain them. Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Gregory Price <gourry@gourry.net> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: "Fabio M. De Francesco" <fabio.m.de.francesco@linux.intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Tested-by: Gregory Price <gourry@gourry.net> Acked-by: Dan Williams <dan.j.williams@intel.com> Link: https://patch.msgid.link/20250509150700.2817697-4-rrichter@amd.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2025-05-09cxl/pci: Moving code in cxl_hdm_decode_init()Robert Richter
Commit 3f9e07531778 ("cxl/pci: simplify the check of mem_enabled in cxl_hdm_decode_init()") changed the code flow in this function. The root port is determined before a check to leave the function. Since the root port is not used by the check it can be moved to run the check first. This improves code readability and avoids unnesessary code execution. Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Gregory Price <gourry@gourry.net> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: "Fabio M. De Francesco" <fabio.m.de.francesco@linux.intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Tested-by: Gregory Price <gourry@gourry.net> Acked-by: Dan Williams <dan.j.williams@intel.com> Link: https://patch.msgid.link/20250509150700.2817697-3-rrichter@amd.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2025-05-09cxl: Remove else after returnRobert Richter
Remove unnecessary 'else' after return. Improves readability of code. It is easier to place comments. Check and fix all occurrences under drivers/cxl/. Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Gregory Price <gourry@gourry.net> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: "Fabio M. De Francesco" <fabio.m.de.francesco@linux.intel.com> Tested-by: Gregory Price <gourry@gourry.net> Acked-by: Dan Williams <dan.j.williams@intel.com> Link: https://patch.msgid.link/20250509150700.2817697-2-rrichter@amd.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2025-04-09cxl/pci: Drop the parameter is_port of cxl_gpf_get_dvsec()Li Ming
The first parameter of cxl_gpf_get_dvsec() is a struct device, can be used to distinguish if the device is a cxl dport or a cxl pci device by checking the PCIe type of it, so the parameter is_port is unnecessary to cxl_gpf_get_dvsec(), using parameter struct device is enough. Signed-off-by: Li Ming <ming.li@zohomail.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Davidlohr Bueso <dave@stgolabs.net> Link: https://patch.msgid.link/20250323093110.233040-4-ming.li@zohomail.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2025-04-09cxl/pci: Update Port GPF timeout only when the first EP attachingLi Ming
update_gpf_port_dvsec() is used to update GPF Phase timeout, if a CXL switch is under a CXL root port, update_gpf_port_dvsec() will be invoked on the CXL root port when each cxl memory device under the CXL switch is attaching. It is enough to be invoked once, others are redundant. When the first EP attaching, it always triggers its ancestor dports to locate their own Port GPF DVSEC. The change is that invoking update_gpf_port_dvsec() on these ancestor dports after ancestor dport locating a Port GPF DVSEC. It guarantees that update_gpf_port_dvsec() is invoked on a dport only happens during the first EP attaching. Signed-off-by: Li Ming <ming.li@zohomail.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Davidlohr Bueso <dave@stgolabs.net> Link: https://patch.msgid.link/20250323093110.233040-3-ming.li@zohomail.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2025-04-09cxl/core: Fix caching dport GPF DVSEC issueLi Ming
Per Table 8-2 in CXL r3.2 section 8.1.1 and CXL r3.2 section 8.1.6, only CXL Downstream switch ports and CXL root ports have GPF DVSEC for CXL Port(DVSEC ID 04h). CXL subsystem has a gpf_dvsec in struct cxl_port which is used to cache the offset of a GPF DVSEC in PCIe configuration space. It will be updated during the first EP attaching to the cxl_port, so the gpf_dvsec can only cache the GPF DVSEC offset of the dport which the first EP is under. Will not have chance to update it during other EPs attaching. That means CXL subsystem will use the same GPF DVSEC offset for all dports under the port, it will be a problem if the GPF DVSEC offset cached in cxl_port is not the right offset for a dport. Moving gpf_dvsec from struct cxl_port to struct cxl_dport, make every cxl dport has their own GPF DVSEC offset caching, and each cxl dport uses its own GPF DVSEC offset for GPF DVSEC accessing. Fixes: a52b6a2c1c99 ("cxl/pci: Support Global Persistent Flush (GPF)") Signed-off-by: Li Ming <ming.li@zohomail.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Davidlohr Bueso <dave@stgolabs.net> Link: https://patch.msgid.link/20250323093110.233040-2-ming.li@zohomail.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2025-03-14cxl/pci: Introduce cxl_gpf_get_dvsec()Davidlohr Bueso
Add a helper to fetch the port/device GPF dvsecs. This is currently only used for ports, but a later patch to export dirty count to users will make use of the device one. Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Li Ming <ming.li@zohomail.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://patch.msgid.link/20250220220235.276831-2-dave@stgolabs.net Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2025-03-14cxl/pci: Support Global Persistent Flush (GPF)Davidlohr Bueso
Add support for GPF flows. It is found that the CXL specification around this to be a bit too involved from the driver side. And while this should really all handled by the hardware, this patch takes things with a grain of salt. Upon respective port enumeration, both phase timeouts are set to a max of 20 seconds, which is the NMI watchdog default for lockup detection. The premise is that the kernel does not have enough information to set anything better than a max across the board and hope devices finish their GPF flows within the platform energy budget. Timeout detection is based on dirty Shutdown semantics. The driver will mark it as dirty, expecting that the device clear it upon a successful GPF event. The admin may consult the device Health and check the dirty shutdown counter to see if there was a problem with data integrity. [ davej: Explicitly set return to 0 in update_gpf_port_dvsec() ] [ davej: Add spec reference for 'struct cxl_mbox_set_shutdown_state_in ] [ davej: Fix 0-day reported issue ] Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://patch.msgid.link/20250124233533.910535-1-dave@stgolabs.net Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2025-01-29Merge tag 'cxl-for-6.14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl Pull Compute Express Link (CXL) updates from Dave Jiang: "A tweak to the HMAT output that was acked by Rafael, a prep patch for CXL type2 devices support that's coming soon, refactoring of the CXL regblock enumeration code, and a series of patches to update the event records to CXL spec r3.1: - Move HMAT printouts to pr_debug() - Add CXL type2 support to cxl_dvsec_rr_decode() in preparation for type2 support - A series that updates CXL event records to spec r3.1 and related changes - Refactoring of cxl_find_regblock_instance() to count regblocks" * tag 'cxl-for-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: cxl/core/regs: Refactor out functions to count regblocks of given type cxl/test: Update test code for event records to CXL spec rev 3.1 cxl/events: Update Memory Module Event Record to CXL spec rev 3.1 cxl/events: Update DRAM Event Record to CXL spec rev 3.1 cxl/events: Update General Media Event Record to CXL spec rev 3.1 cxl/events: Add Component Identifier formatting for CXL spec rev 3.1 cxl/events: Update Common Event Record to CXL spec rev 3.1 cxl/pci: Add CXL Type 1/2 support to cxl_dvsec_rr_decode() ACPI/HMAT: Move HMAT messages to pr_debug()
2025-01-03driver core: Constify API device_find_child() and adapt for various usagesZijun Hu
Constify the following API: struct device *device_find_child(struct device *dev, void *data, int (*match)(struct device *dev, void *data)); To : struct device *device_find_child(struct device *dev, const void *data, device_match_t match); typedef int (*device_match_t)(struct device *dev, const void *data); with the following reasons: - Protect caller's match data @*data which is for comparison and lookup and the API does not actually need to modify @*data. - Make the API's parameters (@match)() and @data have the same type as all of other device finding APIs (bus|class|driver)_find_device(). - All kinds of existing device match functions can be directly taken as the API's argument, they were exported by driver core. Constify the API and adapt for various existing usages. BTW, various subsystem changes are squashed into this commit to meet 'git bisect' requirement, and this commit has the minimal and simplest changes to complement squashing shortcoming, and that may bring extra code improvement. Reviewed-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Acked-by: Uwe Kleine-König <ukleinek@kernel.org> # for drivers/pwm Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-4-6623037414d4@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-02cxl/pci: Add CXL Type 1/2 support to cxl_dvsec_rr_decode()Alejandro Lucero
In cxl_dvsec_rr_decode() the pci driver expects to retrieve a cxlds, struct cxl_dev_state, from the driver_data field of struct device. While that works for Type 3, drivers for Type 1/2 devices may not put a cxlds in the driver_data field. In preparation for supporting Type 1/2 devices, replace parameter 'struct device' with 'struct cxl_dev_state' in cxl_dvsec_rr_decode(). Remove the unused parameter 'cxl_port' in cxl_dvsec_rr_decode(). Signed-off-by: Alejandro Lucero <alucerop@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Link: https://patch.msgid.link/20241203162112.5088-1-alucerop@amd.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-12-02module: Convert symbol namespace to string literalPeter Zijlstra
Clean up the existing export namespace code along the same lines of commit 33def8498fdd ("treewide: Convert macro and uses of __section(foo) to __section("foo")") and for the same reason, it is not desired for the namespace argument to be a macro expansion itself. Scripted using git grep -l -e MODULE_IMPORT_NS -e EXPORT_SYMBOL_NS | while read file; do awk -i inplace ' /^#define EXPORT_SYMBOL_NS/ { gsub(/__stringify\(ns\)/, "ns"); print; next; } /^#define MODULE_IMPORT_NS/ { gsub(/__stringify\(ns\)/, "ns"); print; next; } /MODULE_IMPORT_NS/ { $0 = gensub(/MODULE_IMPORT_NS\(([^)]*)\)/, "MODULE_IMPORT_NS(\"\\1\")", "g"); } /EXPORT_SYMBOL_NS/ { if ($0 ~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+),/) { if ($0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/ && $0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(\)/ && $0 !~ /^my/) { getline line; gsub(/[[:space:]]*\\$/, ""); gsub(/[[:space:]]/, "", line); $0 = $0 " " line; } $0 = gensub(/(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/, "\\1(\\2, \"\\3\")", "g"); } } { print }' $file; done Requested-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://mail.google.com/mail/u/2/#inbox/FMfcgzQXKWgMmjdFwwdsfgxzKpVHWPlc Acked-by: Greg KH <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-09-22cxl: Calculate region bandwidth of targets with shared upstream linkDave Jiang
The current bandwidth calculation aggregates all the targets. This simple method does not take into account where multiple targets sharing under a switch or a root port where the aggregated bandwidth can be greater than the upstream link of the switch. To accurately account for the shared upstream uplink cases, a new update function is introduced by walking from the leaves to the root of the hierarchy and clamp the bandwidth in the process as needed. This process is done when all the targets for a region are present but before the final values are send to the HMAT handling code cached access_coordinate targets. The original perf calculation path was kept to calculate the latency performance data that does not require the shared link consideration. The shared upstream link calculation is done as a second pass when all the endpoints have arrived. Testing is done via qemu with CXL hierarchy. run_qemu[1] is modified to support several CXL hierarchy layouts. The following layouts are tested: HB: Host Bridge RP: Root Port SW: Switch EP: End Point 2 HB 2 RP 2 EP: resulting bandwidth: 624 1 HB 2 RP 2 EP: resulting bandwidth: 624 2 HB 2 RP 2 SW 4 EP: resulting bandwidth: 624 Current testing, perf number from SRAT/HMAT is hacked into the kernel code. However with new QEMU support of Generic Target Port that's incoming, the perf data injection is no longer needed. [1]: https://github.com/pmem/run_qemu Suggested-by: Jonathan Cameron <jonathan.cameron@huawei.com> Link: https://lore.kernel.org/linux-cxl/20240501152503.00002e60@Huawei.com/ Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Link: https://patch.msgid.link/20240904001316.1688225-3-dave.jiang@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-09-09cxl/pci: simplify the check of mem_enabled in cxl_hdm_decode_init()Yanfei Xu
Cases can be divided into two categories which are DVSEC range enabled and not enabled when HDM decoders exist but is not enabled. To avoid checking info->mem_enabled, which indicates the enablement of DVSEC range, every time, we can check !info->mem_enabled once in advance. This simplification can make the code clearer. No functional change intended. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Yanfei Xu <yanfei.xu@intel.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Link: https://patch.msgid.link/20240828084231.1378789-5-yanfei.xu@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-09-09cxl/pci: Check Mem_info_valid bit for each applicable DVSECYanfei Xu
In theory a device might set the mem_info_valid bit for a first range after it is ready but before as second range has reached that state. Therefore, the correct approach is to check the Mem_info_valid bit for each applicable DVSEC range against HDM_COUNT, rather than only for the DVSEC range 1. Consequently, let's move the check into the "for loop" that handles each DVSEC range. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Yanfei Xu <yanfei.xu@intel.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Link: https://patch.msgid.link/20240828084231.1378789-4-yanfei.xu@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-09-09cxl/pci: Remove duplicated implementation of waiting for memory_info_validYanfei Xu
commit ce17ad0d5498 ("cxl: Wait Memory_Info_Valid before access memory related info") added another implementation, which is cxl_dvsec_mem_range_valid(), of waiting for memory_info_valid without realizing it duplicated wait_for_valid(). Remove wait_for_valid() and retain cxl_dvsec_mem_range_valid() as the former is hardcoded to check only the Memory_Info_Valid bit of DVSEC range 1, while the latter allows for selection between DVSEC range 1 or 2 via parameter. Suggested-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Yanfei Xu <yanfei.xu@intel.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Link: https://patch.msgid.link/20240828084231.1378789-3-yanfei.xu@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-09-09cxl/pci: Fix to record only non-zero rangesYanfei Xu
The function cxl_dvsec_rr_decode() retrieves and records DVSEC ranges into info->dvsec_range[], regardless of whether it is non-zero range, and the variable info->ranges indicates the number of non-zero ranges. However, in cxl_hdm_decode_init(), the validation for info->dvsec_range[] occurs in a for loop that iterates based on info->ranges. It may result in zero range to be validated but non-zero range not be validated, in turn, the number of allowed ranges is to be 0. Address it by only record non-zero ranges. This fix is not urgent as it requires a configuration that zeroes out the first dvsec range while populating the second. This has not been observed, but it is theoretically possible. If this gets picked up for -stable, no harm done, but there is no urgency to backport. Fixes: 560f78559006 ("cxl/pci: Retrieve CXL DVSEC memory info") Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Yanfei Xu <yanfei.xu@intel.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Link: https://patch.msgid.link/20240828084231.1378789-2-yanfei.xu@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-09-03cxl/pci: Remove duplicate host_bridge->native_aer checkingLi Ming
cxl_dport_init_ras_reporting() already checks host_bridge->native_aer before invoking cxl_disable_rch_root_ints(), so cxl_disable_rch_root_ints() does not need to check it again. Signed-off-by: Li Ming <ming4.li@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://patch.msgid.link/20240830061308.2327065-3-ming4.li@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-09-03cxl/pci: cxl_dport_map_rch_aer() cleanupLi Ming
cxl_dport_map_ras() is used to map CXL RAS capability, the RCH AER capability should not be mapped in the function but should mapped in cxl_dport_init_ras_reporting(). Moving cxl_dport_map_ras() out of cxl_dport_map_ras() and into cxl_dport_init_ras_reporting(). In cxl_dport_init_ras_reporting(), the AER capability position in RCRB will be located but the position is only used in cxl_dport_map_rch_aer(), getting the position in cxl_dport_map_rch_aer() rather than cxl_dport_init_ras_reporting() is more reasonable and makes the code clearer. Besides, some local variables in cxl_dport_map_rch_aer() are unnecessary, remove them to make the function more concise. Signed-off-by: Li Ming <ming4.li@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://patch.msgid.link/20240830061308.2327065-2-ming4.li@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-09-03cxl/pci: Rename cxl_setup_parent_dport() and cxl_dport_map_regs()Li Ming
The name of cxl_setup_parent_dport() function is not clear, the function is used to initialize AER and RAS capabilities on a dport, therefore, rename the function to cxl_dport_init_ras_reporting(), it is easier for user to understand what the function does. Besides, adjust the order of the function parameters, the subject of cxl_dport_init_ras_reporting() is a cxl dport, so a struct cxl_dport as the first parameter of the function should be better. cxl_dport_map_regs() is used to map CXL RAS capability on a cxl dport, using cxl_dport_map_ras() as the function name. Signed-off-by: Li Ming <ming4.li@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://patch.msgid.link/20240830061308.2327065-1-ming4.li@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-09-03cxl/port: Use __free() to drop put_device() for cxl_portLi Ming
Using scope-based resource management __free() marco with a new helper called put_cxl_port() to drop open coded the put_device() used to dereference the 'struct device' in cxl_port. Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Li Ming <ming4.li@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://patch.msgid.link/20240830013138.2256244-1-ming4.li@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-08-09cxl/pci: Get AER capability address from RCRB only for RCH dportLi Ming
cxl_setup_parent_dport() needs to get RCH dport AER capability address from RCRB to disable AER interrupt. The function does not check if dport is RCH dport, it will get a wrong pci_host_bridge structure by dport_dev in VH case because dport_dev points to a pci device(RP or switch DSP) rather than a pci host bridge device. Fixes: f05fd10d138d ("cxl/pci: Add RCH downstream port AER register discovery") Signed-off-by: Li Ming <ming4.li@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Tested-by: Ira Weiny <ira.weiny@intel.com> Tested-by: Alison Schofield <alison.schofield@intel.com> Link: https://patch.msgid.link/20240809082750.3015641-2-ming4.li@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-07-17cxl/core/pci: Move reading of control register to immediately before usageForyun Ma
Relocate the reading of the DVSEC control register to immediately before usage and avoid unnecessary PCI config access from the read if DVSEC capability check, hdm_count check, or device validity check results in failure. Signed-off-by: Foryun Ma <foryun.ma@jaguarmicro.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Link: https://patch.msgid.link/20240604032151.655-1-foryun.ma@jaguarmicro.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-05-08cxl: Add post-reset warning if reset results in loss of previously committed ↵Dave Jiang
HDM decoders Secondary Bus Reset (SBR) is equivalent to a device being hot removed and inserted again. Doing a SBR on a CXL type 3 device is problematic if the exported device memory is part of system memory that cannot be offlined. The event is equivalent to violently ripping out that range of memory from the kernel. While the hardware requires the "Unmask SBR" bit set in the Port Control Extensions register and the kernel currently does not unmask it, user can unmask this bit via setpci or similar tool. The driver does not have a way to detect whether a reset coming from the PCI subsystem is a Function Level Reset (FLR) or SBR. The only way to detect is to note if a decoder is marked as enabled in software but the decoder control register indicates it's not committed. Add a helper function to find discrepancy between the decoder software state versus the hardware register state. Suggested-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/20240502165851.1948523-6-dave.jiang@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com>
2024-05-08PCI/CXL: Move CXL Vendor ID to pci_ids.hDave Jiang
Move PCI_DVSEC_VENDOR_ID_CXL in CXL private code to PCI_VENDOR_ID_CXL in pci_ids.h in order to be utilized in PCI subsystem. While the CXL Vendor ID (0x1e98) is not listed in the PCI SIG "Member Companies" database at https://pcisig.com/membership/member-companies, the SIG has confirmed that it is reserved by CXL. Link: https://lore.kernel.org/r/20240502165851.1948523-2-dave.jiang@intel.com Suggested-by: Bjorn Helgaas <helgaas@kernel.org> Link: https://lore.kernel.org/linux-cxl/20240402172323.GA1818777@bhelgaas/ Signed-off-by: Dave Jiang <dave.jiang@intel.com> [bhelgaas: update commit log] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com>
2024-03-13lib/firmware_table: Provide buffer length argument to cdat_table_parse()Robert Richter
There exist card implementations with a CDAT table using a fixed size buffer, but with entries filled in that do not fill the whole table length size. Then, the last entry in the CDAT table may not mark the end of the CDAT table buffer specified by the length field in the CDAT header. It can be shorter with trailing unused (zero'ed) data. The actual table length is determined while reading all CDAT entries of the table with DOE. If the table is greater than expected (containing zero'ed trailing data), the CDAT parser fails with: [ 48.691717] Malformed DSMAS table length: (24:0) [ 48.702084] [CDAT:0x00] Invalid zero length [ 48.711460] cxl_port endpoint1: Failed to parse CDAT: -22 In addition, a check of the table buffer length is missing to prevent an out-of-bound access then parsing the CDAT table. Hardening code against device returning borked table. Fix that by providing an optional buffer length argument to acpi_parse_entries_array() that can be used by cdat_table_parse() to propagate the buffer size down to its users to check the buffer length. This also prevents a possible out-of-bound access mentioned. Add a check to warn about a malformed CDAT table length. Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Len Brown <lenb@kernel.org> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/ZdEnopFO0Tl3t2O1@rric.localdomain Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-03-12cxl/pci: Get rid of pointer arithmetic reading CDAT tableRobert Richter
Reading the CDAT table using DOE requires a Table Access Response Header in addition to the CDAT entry. In current implementation this has caused offsets with sizeof(__le32) to the actual buffers. This led to hardly readable code and even bugs. E.g., see fix of devm_kfree() in read_cdat_data(): commit c65efe3685f5 ("cxl/cdat: Free correct buffer on checksum error") Rework code to avoid calculations with sizeof(__le32). Introduce struct cdat_doe_rsp for this which contains the Table Access Response Header and a variable payload size for various data structures afterwards to access the CDAT table and its CDAT Data Structures without recalculating buffer offsets. Cc: Lukas Wunner <lukas@wunner.de> Cc: Fan Ni <nifan.cxl@gmail.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20240216155844.406996-3-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-03-12cxl/pci: Rename DOE mailbox handle to doe_mbRobert Richter
Trivial variable rename for the DOE mailbox handle from cdat_doe to doe_mb. The variable name cdat_doe is too ambiguous, use doe_mb that is commonly used for the mailbox. Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20240216155844.406996-2-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-02-16cxl/pci: Fix disabling memory if DVSEC CXL Range does not match a CFMWS windowRobert Richter
The Linux CXL subsystem is built on the assumption that HPA == SPA. That is, the host physical address (HPA) the HDM decoder registers are programmed with are system physical addresses (SPA). During HDM decoder setup, the DVSEC CXL range registers (cxl-3.1, 8.1.3.8) are checked if the memory is enabled and the CXL range is in a HPA window that is described in a CFMWS structure of the CXL host bridge (cxl-3.1, 9.18.1.3). Now, if the HPA is not an SPA, the CXL range does not match a CFMWS window and the CXL memory range will be disabled then. The HDM decoder stops working which causes system memory being disabled and further a system hang during HDM decoder initialization, typically when a CXL enabled kernel boots. Prevent a system hang and do not disable the HDM decoder if the decoder's CXL range is not found in a CFMWS window. Note the change only fixes a hardware hang, but does not implement HPA/SPA translation. Support for this can be added in a follow on patch series. Signed-off-by: Robert Richter <rrichter@amd.com> Fixes: 34e37b4c432c ("cxl/port: Enable HDM Capability after validating DVSEC Ranges") Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20240216160113.407141-1-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>