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path: root/drivers/cxl/core/regs.c
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2022-12-05cxl/regs: Fix sparse warningDan Williams
The 0day robot belatedly points out that @addr is not properly tagged as an iomap pointer: "drivers/cxl/core/regs.c:332:14: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected void *addr @@ got void [noderef] __iomem * @@" Fixes: 1168271ca054 ("cxl/acpi: Extract component registers of restricted hosts from RCRB") Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Robert Richter <rrichter@amd.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Link: https://lore.kernel.org/r/167008768190.2516013.11918622906007677341.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-12-05Merge branch 'for-6.2/cxl-aer' into for-6.2/cxlDan Williams
Pick up CXL AER handling and correctable error extensions. Resolve conflicts with cxl_pmem_wq reworks and RCH support.
2022-12-03cxl/pci: Find and map the RAS Capability StructureDan Williams
The RAS Capability Structure has some ancillary information that may be relevant with respect to AER events, link and protcol error status registers. Map the RAS Capability Registers in support of defining a 'struct pci_error_handlers' instance for the cxl_pci driver. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/166974412803.1608150.7096566580400947001.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-12-03cxl/pci: Prepare for mapping RAS Capability StructureDan Williams
The RAS Capabilitiy Structure is a CXL Component register capability block. Unlike the HDM Decoder Capability, it will be referenced by the cxl_pci driver in response to PCIe AER events. Due to this it is no longer the case that cxl_map_component_regs() can assume that it should map all component registers. Plumb a bitmask of capability ids to map through cxl_map_component_regs(). For symmetry cxl_probe_device_regs() is updated to populate @id in 'struct cxl_reg_map' even though cxl_map_device_regs() does not have a need to map a subset of the device registers per caller. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/166974412214.1608150.11487843455070795378.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-12-03cxl/core/regs: Make cxl_map_{component, device}_regs() device genericDan Williams
There is no need to carry the barno and the block offset through the stack, just convert them to a resource base immediately. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/166974411035.1608150.8605988708101648442.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-12-03cxl/pci: Cleanup cxl_map_device_regs()Dan Williams
Use a loop to reduce the duplicated code in cxl_map_device_regs(). This is in preparation for deleting cxl_map_regs(). Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/166974409867.1608150.14886452053935226038.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-12-03cxl/pci: Cleanup repeated code in cxl_probe_regs() helpersDan Williams
Rather then duplicating the setting of valid, length, and offset for each type, just convey a pointer to the register map to common code. Yes, the change in cxl_probe_component_regs() does not save any lines of code, but it is preparation for adding another component register type to map (RAS Capability Structure). Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/166974409293.1608150.17661353937678581423.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-12-03cxl/acpi: Extract component registers of restricted hosts from RCRBRobert Richter
A downstream port must be connected to a component register block. For restricted hosts the base address is determined from the RCRB. The RCRB is provided by the host's CEDT CHBS entry. Rework CEDT parser to get the RCRB and add code to extract the component register block from it. RCRB's BAR[0..1] point to the component block containing CXL subsystem component registers. MEMBAR extraction follows the PCI base spec here, esp. 64 bit extraction and memory range alignment (6.0, 7.5.1.2.1). The RCRB base address is cached in the cxl_dport per-host bridge so that the upstream port component registers can be retrieved later by an RCD (RCIEP) associated with the host bridge. Note: Right now the component register block is used for HDM decoder capability only which is optional for RCDs. If unsupported by the RCD, the HDM init will fail. It is future work to bypass it in this case. Co-developed-by: Terry Bowman <terry.bowman@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Signed-off-by: Robert Richter <rrichter@amd.com> Link: https://lore.kernel.org/r/Y4dsGZ24aJlxSfI1@rric.localdomain [djbw: introduce devm_cxl_add_rch_dport()] Link: https://lore.kernel.org/r/166993044524.1882361.2539922887413208807.stgit@dwillia2-xfh.jf.intel.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>
2022-11-14cxl/core: Check physical address before mapping it in devm_cxl_iomap_block()Robert Richter
The physical base address of a CXL range can be invalid and is then set to CXL_RESOURCE_NONE. In general software shall prevent such situations, but it is hard to proof this may never happen. E.g. in add_port_attach_ep() there this the following: component_reg_phys = find_component_registers(uport_dev); port = devm_cxl_add_port(&parent_port->dev, uport_dev, component_reg_phys, parent_dport); find_component_registers() and subsequent functions (e.g. cxl_regmap_to_base()) may return CXL_RESOURCE_NONE. But it is written to port without any further check in cxl_port_alloc(): port->component_reg_phys = component_reg_phys; It is then later directly used in devm_cxl_setup_hdm() to map io ranges with devm_cxl_iomap_block(). Just an example... Check this condition. Also do not fail silently like an ioremap() failure, use a WARN_ON_ONCE() for it. Signed-off-by: Robert Richter <rrichter@amd.com> Link: https://lore.kernel.org/r/20221018132341.76259-3-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-11-14cxl/core: Remove duplicate declaration of devm_cxl_iomap_block()Robert Richter
The function devm_cxl_iomap_block() is only used in the core code. There are two declarations in header files of it, in drivers/cxl/core/core.h and drivers/cxl/cxl.h. Remove its unused declaration in drivers/cxl/cxl.h. Fixing build error in regs.c found by kernel test robot by including "core.h" there. Signed-off-by: Robert Richter <rrichter@amd.com> Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/20221018132341.76259-2-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/regs: Fix size of CXL Capability Header RegisterJonathan Cameron
In CXL 2.0, 8.2.5.1 CXL Capability Header Register: this register is given as 32 bits. 8.2.3 which covers the CXL 2.0 Component registers, including the CXL Capability Header Register states that access restrictions specified in Section 8.2.2 apply. 8.2.2 includes: * A 32 bit register shall be accessed as a 4 Byte quantity. ... If these rules are not followed, the behavior is undefined. Discovered during review of CXL QEMU emulation. Alex Bennée pointed out there was a comment saying that 4 byte registers must be read with a 4 byte read, but 8 byte reads were being emulated. https://lore.kernel.org/qemu-devel/87bkzyd3c7.fsf@linaro.org/ Fixing that, led to this code failing. Whilst a given hardware implementation 'might' work with an 8 byte read, it should not be relied upon. The QEMU emulation v5 will return 0 and log the wrong access width. The code moved, so one fixes tag for where this will directly apply and also a reference to the earlier introduction of the code for backports. Fixes: 0f06157e0135 ("cxl/core: Move register mapping infrastructure") Fixes: 08422378c4ad ("cxl/pci: Add HDM decoder capabilities") Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/20220201153437.2873-1-Jonathan.Cameron@huawei.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/core/hdm: Add CXL standard decoder enumeration to the coreDan Williams
Unlike the decoder enumeration for "root decoders" described by platform firmware, standard decoders can be enumerated from the component registers space once the base address has been identified (via PCI, ACPI, or another mechanism). Add common infrastructure for HDM (Host-managed-Device-Memory) Decoder enumeration and share it between host-bridge, upstream switch port, and cxl_test defined decoders. The locking model for switch level decoders is to hold the port lock over the enumeration. This facilitates moving the dport and decoder enumeration to a 'port' driver. For now, the only enumerator of decoder resources is the cxl_acpi root driver. Co-developed-by: Ben Widawsky <ben.widawsky@intel.com> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/164374688404.395335.9239248252443123526.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/pci: Rename pci.h to cxlpci.hDan Williams
Similar to the mem.h rename, if the core wants to reuse definitions from drivers/cxl/pci.h it is unable to use <pci.h> as that collides with archs that have an arch/$arch/include/asm/pci.h, like MIPS. Reported-by: kernel test robot <lkp@intel.com> Acked-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/164298422510.3018233.14693126572756675563.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/core: Fix cxl_probe_component_regs() error messageDan Williams
Fix a '\n' vs '/n' typo. Fixes: 08422378c4ad ("cxl/pci: Add HDM decoder capabilities") Acked-by: Ben Widawsky <ben.widawsky@intel.com Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/164298418268.3018233.17790073375430834911.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/acpi: Map component registers for Root PortsBen Widawsky
This implements the TODO in cxl_acpi for mapping component registers. cxl_acpi becomes the second consumer of CXL register block enumeration (cxl_pci being the first). Moving the functionality to cxl_core allows both of these drivers to use the functionality. Equally importantly it allows cxl_core to use the functionality in the future. CXL 2.0 root ports are similar to CXL 2.0 Downstream Ports with the main distinction being they're a part of the CXL 2.0 host bridge. While mapping their component registers is not immediately useful for the CXL drivers, the movement of register block enumeration into core is a vital step towards HDM decoder programming. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> [djbw: fix cxl_regmap_to_base() failure cases] Link: https://lore.kernel.org/r/164298415080.3018233.14694957480228676592.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15cxl/core: Convert to EXPORT_SYMBOL_NS_GPLDan Williams
It turns out that the usb example of specifying the subsystem namespace at build time is not preferred. The rationale for that preference has become more apparent as CXL patches with plain EXPORT_SYMBOL_GPL beg the question, "why would any code other than CXL care about this symbol?". Make the namespace explicit. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163676356810.3618264.601632777702192938.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-07cxl/registers: Fix Documentation warningDan Williams
Commit 0f06157e0135 ("cxl/core: Move register mapping infrastructure") neglected to add a DOC header for the new drivers/core/regs.c file. Reported-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163072206675.2250120.3527179192933919995.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-08-06cxl/core: Move register mapping infrastructureDan Williams
The register mapping infrastructure is large enough to move to its own compilation unit. This also cleans up an unnecessary include of <mem.h> core/bus.c. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/162800068975.665205.12895551621746585289.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>