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2022-05-20cxl/port: Enable HDM Capability after validating DVSEC RangesDan Williams1-15/+152
CXL memory expanders that support the CXL 2.0 memory device class code include an "HDM Decoder Capability" mechanism to supplant the "CXL DVSEC Range" mechanism originally defined in CXL 1.1. Both mechanisms depend on a "mem_enable" bit being set in configuration space before either mechanism activates. When the HDM Decoder Capability is enabled the CXL DVSEC Range settings are ignored. Previously, the cxl_mem driver was relying on platform-firmware to set "mem_enable". That is an invalid assumption as there is no requirement that platform-firmware sets the bit before the driver sees a device, especially in hot-plug scenarios. Additionally, ACPI-platforms that support CXL 2.0 devices also support the ACPI CEDT (CXL Early Discovery Table). That table outlines the platform permissible address ranges for CXL operation. So, there is a need for the driver to set "mem_enable", and there is information available to determine the validity of the CXL DVSEC Ranges. Arrange for the driver to optionally enable the HDM Decoder Capability if "mem_enable" was not set by platform firmware, or the CXL DVSEC Range configuration was invalid. Be careful to only disable memory decode if the kernel was the one to enable it. In other words, if CXL is backing all of kernel memory at boot the device needs to maintain "mem_enable" and "HDM Decoder enable" all the way up to handoff back to platform firmware (e.g. ACPI S5 state entry may require CXL memory to stay active). Fixes: 560f78559006 ("cxl/pci: Retrieve CXL DVSEC memory info") Cc: Dan Carpenter <dan.carpenter@oracle.com> [dan: fix early terminiation of range-allowed loop] Cc: Ariel Sibley <ariel.sibley@microchip.com> [ariel: Memory_size must be non-zero] Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/165307136375.2499769.861793697156744166.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-19cxl/port: Reuse 'struct cxl_hdm' context for hdm initDan Williams3-41/+25
The port driver maps component registers for port operations. Reuse that mapping for HDM Decoder Capability setup / enable. Move devm_cxl_setup_hdm() before cxl_hdm_decode_init() and plumb @cxlhdm through the hdm init helpers. Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165291691712.1426646.14336397551571515480.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-19cxl/port: Move endpoint HDM Decoder Capability init to port driverDan Williams2-11/+11
The responsibility for establishing HDM Decoder Capability based operation is more closely tied to port enabling than memdev enabling which is concerned with port enumeration. This later enables reusing @cxlhdm for probing / controlling "global enable" for the HDM Decoder Capability. For now, just do the nominal move. Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165291691167.1426646.7936109077255288258.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-19cxl/pci: Drop @info argument to cxl_hdm_decode_init()Dan Williams3-13/+9
Now that nothing external to cxl_hdm_decode_init() considers 'struct cxl_endpoint_dvec_info' move it internal to cxl_hdm_decode_init(). Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165291690612.1426646.7866084245521113414.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-19cxl/mem: Merge cxl_dvsec_ranges() and cxl_hdm_decode_init()Dan Williams3-88/+78
In preparation for changing how the driver handles 'mem_enable' in the CXL DVSEC control register. Merge the contents of cxl_hdm_decode_init() into cxl_dvsec_ranges() and rename the combined function cxl_hdm_decode_init(). The possible cleanups and fixes that result from this merge are saved for a follow-on change. Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/165291690027.1426646.10249756632415633752.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-19cxl/mem: Skip range enumeration if mem_enable clearDan Williams2-1/+3
When a device does not have mem_enable set then the current range settings are moot. Skip the enumeration and cause cxl_hdm_decode_init() to proceed directly to enable the HDM Decoder Capability. Fixes: 560f78559006 ("cxl/pci: Retrieve CXL DVSEC memory info") Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165291689442.1426646.18012291761753694336.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-19cxl/mem: Consolidate CXL DVSEC Range enumeration in the coreDan Williams5-142/+141
In preparation for fixing the setting of the 'mem_enabled' bit in CXL DVSEC Control register, move all CXL DVSEC range enumeration into the same source file. Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165291688886.1426646.15046138604010482084.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-19cxl/pci: Move cxl_await_media_ready() to the coreDan Williams4-47/+51
Allow cxl_await_media_ready() to be mocked for testing purposes rather than carrying the maintenance burden of an indirect function call in the mainline driver. With the move cxl_await_media_ready() can no longer reuse the mailbox timeout override, so add a media_ready_timeout module parameter to the core to backfill. Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165291688340.1426646.4755627801983775011.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-19cxl/mem: Validate port connectivity before dvsec rangesDan Williams1-16/+16
In preparation for validating DVSEC ranges against the platform declared CXL memory ranges (ACPI CFMWS) move port enumeration before the endpoint's decoder validation. Ultimately this logic will move to the port driver, but create a bisect point before that larger move. Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165291687749.1426646.18091538443879226995.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-19cxl/mem: Fix cxl_mem_probe() error exitDan Williams1-2/+4
The addition of cxl_mem_active() broke error exit scenarios for cxl_mem_probe(). Return early rather than proceed with disabling suspend, and update the label name since it is no longer a terminal "out" label that exits the function. Fixes: 9ea4dcf49878 ("PM: CXL: Disable suspend") Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165291687176.1426646.15449254938752532784.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-19cxl/pci: Drop wait_for_valid() from cxl_await_media_ready()Dan Williams1-4/+0
A check mem_info_valid already happens in __cxl_dvsec_ranges(). Rely on that instead of calling wait_for_valid again. Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165291686632.1426646.7479581732894574486.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-19cxl/pci: Consolidate wait_for_media() and wait_for_media_ready()Dan Williams2-20/+3
Now that wait_for_media() does nothing supplemental to wait_for_media_ready() just promote wait_for_media_ready() to a common helper and drop wait_for_media(). Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165291686046.1426646.4390664747934592185.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-19cxl/mem: Drop mem_enabled check from wait_for_media()Dan Williams1-4/+0
Media ready is asserted by the device independent of whether mem_enabled was ever set. Drop this check to allow for dropping wait_for_media() in favor of ->wait_media_ready(). Fixes: 8dd2bc0f8e02 ("cxl/mem: Add the cxl_mem driver") Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165291685501.1426646.10372821863672431074.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-28cxl: Drop cxl_device_lock()Dan Williams5-120/+33
Now that all CXL subsystem locking is validated with custom lock classes, there is no need for the custom usage of the lockdep_mutex. Cc: Alison Schofield <alison.schofield@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Ben Widawsky <ben.widawsky@intel.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/165055520383.3745911.53447786039115271.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-28cxl/acpi: Add root device lockdep validationDan Williams1-0/+13
The CXL "root" device, ACPI0017, is an attach point for coordinating platform level CXL resources and is the parent device for a CXL port topology tree. As such it has distinct locking rules relative to other CXL subsystem objects, but because it is an ACPI device the lock class is established well before it is given to the cxl_acpi driver. However, the lockdep API does support changing the lock class "live" for situations like this. Add a device_lock_set_class() helper that a driver can use in ->probe() to set a custom lock class, and device_lock_reset_class() to return to the default "no validate" class before the custom lock class key goes out of scope after ->remove(). Note the helpers are all macros to support dead code elimination in the CONFIG_PROVE_LOCKING=n case, however device_set_lock_class() still needs #ifdef CONFIG_PROVE_LOCKING since lockdep_match_class() explicitly does not have a helper in the CONFIG_PROVE_LOCKING=n case (see comment in lockdep.h). The lockdep API needs 2 small tweaks to prevent "unused" warnings for the @key argument to lock_set_class(), and a new lock_set_novalidate_class() is added to supplement lockdep_set_novalidate_class() in the cases where the lock class is converted while the lock is held. Suggested-by: Peter Zijlstra <peterz@infradead.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Will Deacon <will@kernel.org> Cc: Waiman Long <longman@redhat.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Alison Schofield <alison.schofield@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Ben Widawsky <ben.widawsky@intel.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/165100081305.1528964.11138612430659737238.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-28cxl: Replace lockdep_mutex with local lock classesDan Williams3-4/+18
In response to an attempt to expand dev->lockdep_mutex for device_lock() validation [1], Peter points out [2] that the lockdep API already has the ability to assign a dedicated lock class per subsystem device-type. Use lockdep_set_class() to override the default device_lock() '__lockdep_no_validate__' class for each CXL subsystem device-type. This enables lockdep to detect deadlocks and recursive locking within the device-driver core and the subsystem. The lockdep_set_class_and_subclass() API is used for port objects that recursively lock the 'cxl_port_key' class by hierarchical topology depth. Link: https://lore.kernel.org/r/164982968798.684294.15817853329823976469.stgit@dwillia2-desk3.amr.corp.intel.com [1] Link: https://lore.kernel.org/r/Ylf0dewci8myLvoW@hirez.programming.kicks-ass.net [2] Suggested-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Will Deacon <will@kernel.org> Cc: Waiman Long <longman@redhat.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Alison Schofield <alison.schofield@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Ben Widawsky <ben.widawsky@intel.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/165055519317.3745911.7342499516839702840.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-28cxl/mbox: fix logical vs bitwise typoDan Carpenter1-1/+1
This should be bitwise & instead of &&. Fixes: 6179045ccc0c ("cxl/mbox: Block immediate mode in SET_PARTITION_INFO command") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/YmpgkbbQ1Yxu36uO@kili Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-22cxl/mbox: Replace NULL check with IS_ERR() after vmemdup_user()Alison Schofield1-1/+1
vmemdup_user() returns an ERR_PTR() on failure. Use IS_ERR() to check the return value. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20220407010915.1211258-1-alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-22cxl/mbox: Use type __u32 for mailbox payload sizesAlison Schofield1-13/+15
Payload sizes for mailbox commands are expected to be positive values coming from userspace. The documentation correctly describes these as always unsigned values. The mailbox and send structures that support the mailbox commands however, use __s32 types for the payloads. Replace __s32 with __u32 in the mailbox and send command structures and update usages. Kernel users of the interface already block all negative values and there is no known ability for userspace to have grown a dependency on submitting negative values to the kernel. The known user of the IOCTL, the CXL command line interface (cxl-cli) already enforces positive size values. A Smatch warning of a signedness uncovered this issue. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Alison Schofield <alison.schofield@intel.com> Link: https://lore.kernel.org/r/20220414051246.1244575-1-alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-22PM: CXL: Disable suspendDan Williams6-2/+62
The CXL specification claims S3 support at a hardware level, but at a system software level there are some missing pieces. Section 9.4 (CXL 2.0) rightly claims that "CXL mem adapters may need aux power to retain memory context across S3", but there is no enumeration mechanism for the OS to determine if a given adapter has that support. Moreover the save state and resume image for the system may inadvertantly end up in a CXL device that needs to be restored before the save state is recoverable. I.e. a circular dependency that is not resolvable without a third party save-area. Arrange for the cxl_mem driver to fail S3 attempts. This still nominaly allows for suspend, but requires unbinding all CXL memory devices before the suspend to ensure the typical DRAM flow is taken. The cxl_mem unbind flow is intended to also tear down all CXL memory regions associated with a given cxl_memdev. It is reasonable to assume that any device participating in a System RAM range published in the EFI memory map is covered by aux power and save-area outside the device itself. So this restriction can be minimized in the future once pre-existing region enumeration support arrives, and perhaps a spec update to clarify if the EFI memory map is sufficent for determining the range of devices managed by platform-firmware for S3 support. Per Rafael, if the CXL configuration prevents suspend then it should fail early before tasks are frozen, and mem_sleep should stop showing 'mem' as an option [1]. Effectively CXL augments the platform suspend ->valid() op since, for example, the ACPI ops are not aware of the CXL / PCI dependencies. Given the split role of platform firmware vs OS provisioned CXL memory it is up to the cxl_mem driver to determine if the CXL configuration has elements that platform firmware may not be prepared to restore. Link: https://lore.kernel.org/r/CAJZ5v0hGVN_=3iU8OLpHY3Ak35T5+JcBM-qs8SbojKrpd0VXsA@mail.gmail.com [1] Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Len Brown <len.brown@intel.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/165066828317.3907920.5690432272182042556.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/mem: Replace redundant debug message with a commentDan Williams1-4/+10
cxl_mem_probe() already emits a log message when HDM operation can not be established. Delete the similar one in cxl_hdm_decode_init(). What is less obvious is why global_ctrl being enabled makes positive values of info->ranges irrelevant, and the Linux behavior with respect to the spec recommendation to mirror CXL Range registers with HDM Decoder Base + Size registers. Cc: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Link: https://lore.kernel.org/r/164944616743.454665.7055846627973202403.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/mem: Rename cxl_dvsec_decode_init() to cxl_hdm_decode_init()Dan Williams1-6/+6
cxl_dvsec_decode_init() is tasked with checking whether legacy DVSEC range based decode is in effect, or whether HDM can be enabled / already is enabled. As such it either succeeds or fails and that result is the return value. The @do_hdm_init variable is misleading in the case where HDM operation is already found to be active, so just call it @retval. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Link: https://lore.kernel.org/r/164730736435.3806189.2537160791687837469.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/pci: Make cxl_dvsec_ranges() failure not fatal to cxl_pciDan Williams1-9/+18
cxl_dvsec_ranges(), the helper for enumerating the presence of an active legacy CXL.mem configuration on a CXL 2.0 Memory Expander, is not fatal for cxl_pci because there is still value to enable mailbox operations even if CXL.mem operation is disabled. Recall that the reason cxl_pci does this initialization and not cxl_mem is to preserve the useful property (for unit testing) that cxl_mem is cxl_memdev + mmio generic, and does not require access to a 'struct pci_dev' to issue config cycles. Update 'struct cxl_endpoint_dvsec_info' to carry either a positive number of non-zero size legacy CXL DVSEC ranges, or the negative error code from __cxl_dvsec_ranges() in its @ranges member. Reported-by: Krzysztof Zach <krzysztof.zach@intel.com> Fixes: 560f78559006 ("cxl/pci: Retrieve CXL DVSEC memory info") Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Link: https://lore.kernel.org/r/164730735869.3806189.4032428192652531946.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/mem: Make cxl_dvsec_range() init failure fatalDan Williams1-0/+3
In preparation for the cxl_pci driver to continue operation after cxl_dvsec_range() failure, update cxl_mem to check for negative error codes in info->ranges. Treat that condition as fatal regardless of the state of the HDM configuration since cxl_mem needs positive confirmation that legacy ranges were not established by platform firmware or another agent. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com. Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Link: https://lore.kernel.org/r/164730735324.3806189.4167509857771192422.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/pci: Add debug for DVSEC range init failuresDan Williams1-3/+10
In preparation for not treating DVSEC range initialization failures as fatal to cxl_pci_probe() add individual dev_dbg() statements for each of the major failure reasons in cxl_dvsec_ranges(). The rationale for cxl_dvsec_ranges() failure not being fatal is that there is still value for cxl_pci to enable mailbox operations even if CXL.mem operation is disabled. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Link: https://lore.kernel.org/r/164730734812.3806189.2726330688692684104.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/mem: Drop DVSEC vs EFI Memory Map sanity checkDan Williams1-23/+1
When the driver finds legacy DVSEC ranges active on a CXL Memory Expander it indicates that platform firmware is not aware of, or is deliberately disabling common CXL 2.0 operation. In this case Linux generally has no choice, but to leave the device alone. The driver attempts to validate that the DVSEC range is in the EFI memory map. Remove that logic since there is no requirement that the BIOS publish DVSEC ranges in the EFI Memory Map. In the future the driver will want to permanently reserve this capacity out of the available CFMWS capacity and hide it from request_free_mem_region(), but it serves no purpose to warn about the range not appearing in the EFI Memory Map. Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/164730734246.3806189.13995924771963139898.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/mbox: Use new return_code handlingDavidlohr Bueso2-3/+3
Use the global cxl_mbox_cmd_rc table to improve debug messaging in __cxl_pci_mbox_send_cmd() and allow cxl_mbox_send_cmd() to map to proper kernel style errno codes - this patch continues to use -ENXIO only so no change in semantics. Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed by: Adam Manzanares <a.manzanares@samsung.com> Link: https://lore.kernel.org/r/20220404021216.66841-5-dave@stgolabs.net Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/mbox: Improve handling of mbox_cmd hw return codesDavidlohr Bueso3-3/+54
Upon a completed command the caller is still expected to check the actual return_code register to ensure it succeed. This adds, per the spec, the potential command return codes. It maps the hardware return code with the kernel's errno style, and by default continues to use -ENXIO (Command completed, but device reported an error). Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed by: Adam Manzanares <a.manzanares@samsung.com> Link: https://lore.kernel.org/r/20220404021216.66841-4-dave@stgolabs.net Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/pci: Use CXL_MBOX_SUCCESS to check against mbox_cmd return codeDavidlohr Bueso1-2/+2
Also mention the need for the caller to check against any errors from the hardware in return_code. Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed by: Adam Manzanares <a.manzanares@samsung.com> Link: https://lore.kernel.org/r/20220404021216.66841-3-dave@stgolabs.net Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/mbox: Drop mbox_mutex commentDavidlohr Bueso1-1/+1
... we have lockdep for this. Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed by: Adam Manzanares <a.manzanares@samsung.com> Link: https://lore.kernel.org/r/20220404021216.66841-2-dave@stgolabs.net Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/pmem: Remove CXL SET_PARTITION_INFO from exclusive_cmds listAlison Schofield1-1/+0
With SET_PARTITION_INFO on the exclusive_cmds list for the CXL_PMEM driver, userspace cannot execute a set-partition command without first unbinding the pmem driver from the device. When userspace requests a partition change to take effect on the next reboot this unbind requirement is unnecessarily restrictive. The driver does not need to enforce an unbind because partitions will not change until the next reboot. Of course, userspace still needs to be aware that changing the size of persistent capacity on the next reboot will result in the loss of data stored. That can happen regardless of whether it is presently bound at the time of issuing the set-partition command. When userspace requests a partition change to take effect immediately, restrictions are needed. The CXL_MEM driver currently blocks the usage of immediate mode, making the presence of SET_PARTITION_INFO, in this exclusive commands list, redundant. In the future, when the CXL_MEM driver adds support for immediate changes to device partitions it will ensure that the partition change will not affect any active decode. That means the work will not fall right back here, onto the CXL_PMEM driver. Signed-off-by: Alison Schofield <alison.schofield@intel.com> Link: https://lore.kernel.org/r/accc6abc878f0662093b81490a1a052f2ff6f06e.1648687552.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/mbox: Block immediate mode in SET_PARTITION_INFO commandAlison Schofield2-0/+48
User space may send the SET_PARTITION_INFO mailbox command using the IOCTL interface. Inspect the input payload and fail if the immediate flag is set. This is the first instance of the driver inspecting an input payload from user space. Assume there will be more such cases and implement with an extensible helper. In order for the kernel to react to an immediate partition change it needs to assert that the change will not affect any active decode. At a minimum this requires validating that the device is using HDM decoders instead of the CXL DVSEC for decode, and that none of the active HDM decoders are affected by the partition change. For now, just fail until that support arrives. Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/241821186c363833980adbc389e2c547bc5a6395.1648687552.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/mbox: Move cxl_mem_command param to a local variableAlison Schofield1-12/+8
cxl_validate_command_from_user() is now the single point of validation for mailbox commands coming from user space. Previously, it returned a a cxl_mem_command, but that was not sufficient when validation of the actual mailbox command became a requirement. Now, it returns a fully validated cxl_mbox_cmd. Remove the extraneous cxl_mem_command parameter. Define and use a local version only. Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/c11a437896d914daf36f5ac8ec62f999c5ec2da7.1648687552.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/mbox: Make handle_mailbox_cmd_from_user() use a mbox paramAlison Schofield1-27/+17
Previously, handle_mailbox_cmd_from_user(), constructed the mailbox command and dispatched it to the hardware. The construction work has moved to the validation path. handle_mailbox_cmd_from_user() now expects a fully validated mbox param. Make it's caller, cxl_send_cmd(), deliver it. Update the comments and dereferencing of the new mbox parameter. Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/77050ba512d6c30eccf7505467509e460dd325a0.1648687552.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/mbox: Remove dependency on cxl_mem_command for a debug msgAlison Schofield1-3/+14
In preparation for removing access to struct cxl_mem_command, change this debug message to use cxl_mbox_cmd fields instead. Retrieve the pretty command name from cxl_mbox_cmd using a new opcode to command name helper. Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/57265751d336a6e95f5ca31a9c77189408b05742.1648687552.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/mbox: Construct a users cxl_mbox_cmd in the validation pathAlison Schofield1-4/+17
This is a step in refactoring the handling of user space mailbox commands. The intent is to have all the validation work originate in cxl_validate_cmd_from_user(). Move the construction and validation of a mailbox command to the validation path. Continue to pass both the out_cmd and the mbox_cmd until handle_mbox_cmd_from_user() learns how to use a mbox_cmd param. Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/c9fbdad968a2b619f9108bb6c37cef1a853cdf5a.1648687552.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/mbox: Move build of user mailbox cmd to a helper functionsAlison Schofield1-25/+45
In preparation for moving the construction of a mailbox command to the validation path, extract the work into a helper functions. Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/493d7618a846d787c3ae28778935ca35e2b85eed.1648687552.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/mbox: Move raw command warning to raw command validationAlison Schofield1-3/+2
This move serves two purposes: 1) Emit the warning in the raw command validation path, and 2) Remove the dependency on the struct cxl_mem_command in handle_mailbox_cmd_from_user() in preparation for a refactor of that function. Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/df5f0e0ec8afa1f75299aa86b4226ab4479ef325.1648687552.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-12cxl/mbox: Move cxl_mem_command construction to helper funcsAlison Schofield1-71/+76
Sanitizing and constructing a cxl_mem_command from a userspace command is part of the validation process prior to submitting the command to a CXL device. Move this work to helper functions: cxl_to_mem_cmd(), cxl_to_mem_cmd_raw(). This declutters cxl_validate_cmd_from_user() in preparation for adding new validation steps. Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/7d9b826f29262e3a484cb4bb7b63872134d60bd7.1648687552.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-08cxl/pci: Drop shadowed variableDan Williams1-1/+0
0day reports that wait_for_media_ready() declares an @rc variable twice. >> drivers/cxl/pci.c:439:7: warning: Local variable 'rc' shadows outer variable [shadowVariable] int rc; ^ drivers/cxl/pci.c:431:6: note: Shadowed declaration int rc, i; ^ drivers/cxl/pci.c:439:7: note: Shadow variable int rc; ^ Cc: Randy Dunlap <rdunlap@infradead.org> Fixes: 523e594d9cc0 ("cxl/pci: Implement wait for media active") Acked-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Link: https://lore.kernel.org/r/164944636936.455177.14136200464724208233.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-03-22cxl/core/port: Fix NULL but dereferenced coccicheck errorWan Jiabing1-1/+4
Fix the following coccicheck warning: ./drivers/cxl/core/port.c:913:21-24: ERROR: port is NULL but dereferenced. The put_device() is only relevent in the is_cxl_root() case. Fixes: 2703c16c75ae ("cxl/core/port: Add switch port enumeration") Signed-off-by: Wan Jiabing <wanjiabing@vivo.com> Link: https://lore.kernel.org/r/20220307094158.404882-1-wanjiabing@vivo.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-17cxl/port: Hold port reference until decoder releaseDan Williams1-0/+4
KASAN + DEBUG_KOBJECT_RELEASE reports a potential use-after-free in cxl_decoder_release() where it goes to reference its parent, a cxl_port, to free its id back to port->decoder_ida. BUG: KASAN: use-after-free in to_cxl_port+0x18/0x90 [cxl_core] Read of size 8 at addr ffff888119270908 by task kworker/35:2/379 CPU: 35 PID: 379 Comm: kworker/35:2 Tainted: G OE 5.17.0-rc2+ #198 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Workqueue: events kobject_delayed_cleanup Call Trace: <TASK> dump_stack_lvl+0x59/0x73 print_address_description.constprop.0+0x1f/0x150 ? to_cxl_port+0x18/0x90 [cxl_core] kasan_report.cold+0x83/0xdf ? to_cxl_port+0x18/0x90 [cxl_core] to_cxl_port+0x18/0x90 [cxl_core] cxl_decoder_release+0x2a/0x60 [cxl_core] device_release+0x5f/0x100 kobject_cleanup+0x80/0x1c0 The device core only guarantees parent lifetime until all children are unregistered. If a child needs a parent to complete its ->release() callback that child needs to hold a reference to extend the lifetime of the parent. Fixes: 40ba17afdfab ("cxl/acpi: Introduce cxl_decoder objects") Reported-by: Ben Widawsky <ben.widawsky@intel.com> Tested-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/164505751190.4175768.13324905271463416712.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-17cxl/port: Fix endpoint refcount leakDan Williams1-1/+2
An endpoint can be unregistered via two paths. Either its parent port is unregistered, or the memdev that registered the endpoint is removed. The memdev remove path is responsible for synchronizing against the parent ->remove() event and if the memdev remove path wins, manually trigger unregister_port() via devm_release_action(). Until that race is resolved the memdev remove path holds a reference on the endpoint. If the parent port for the endpoint can not be found that is an indication that the endpoint has already been registered. Be sure to drop the reference in all exit paths from delete_endpoint(). Fixes: 8dd2bc0f8e02 ("cxl/mem: Add the cxl_mem driver") Link: https://lore.kernel.org/r/164454148209.3429624.12905500880311609053.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-11cxl/core: Fix cxl_device_lock() class detectionDan Williams1-1/+1
If cxl_device_lock() is used on a non-CXL device the expectation is that the lock class will fall back to CXL_ANON_LOCK. Instead it crashes when trying to determine if the device is a 'decoder'. Specifically when the device has a NULL type pointer. Just check for NULL before de-referencing ->release. Fixes: 3c5b90395525 ("cxl: Prove CXL locking") Reported-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/164439225406.2941117.3927102269866914339.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-11cxl/core/port: Fix unregister_port() lock assertionDan Williams1-4/+20
The device_lock_assert() in unregister_port() fails to pick the right device leading to splats like the following from: echo "ACPI0017:00" > /sys/bus/platform/drivers/cxl_acpi/unbind WARNING: CPU: 32 PID: 1147 at include/linux/device.h:787 unregister_port+0x49/0x50 [cxl_c [..] RIP: 0010:unregister_port+0x49/0x50 [cxl_core] [..] Call Trace: <TASK> release_nodes+0x63/0x80 devres_release_all+0x8b/0xc0 __device_release_driver+0x190/0x240 device_driver_detach+0x3e/0xa0 unbind_store+0x113/0x130 Fix it up to assert on the device_lock() for ACPI0017 for root and 1st level ports, and parent ports for all the rest. Fixes: 54cdbf845cf7 ("cxl/port: Add a driver for 'struct cxl_port' objects") Reported-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/164439224893.2941117.18331456248117887720.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/regs: Fix size of CXL Capability Header RegisterJonathan Cameron1-2/+2
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/port: Handle invalid decodersDan Williams1-6/+30
In case init_hdm_decoder() finds invalid settings, skip to the next valid decoder. Only fail port enumeration if zero valid decoders are found. This protects the driver init against broken hardware and / or future interleave capabilities. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/164317464918.3438644.12371149695618136198.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/core/port: Fix / relax decoder target enumerationDan Williams2-2/+5
If the decoder is not presently active the target_list may not be accurate. Perform a best effort mapping and assume that it will be fixed up when the decoder is enabled. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/164317464406.3438644.6609329492458460242.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/core/port: Add endpoint decodersBen Widawsky4-16/+73
Recall that a CXL Port is any object that publishes a CXL HDM Decoder Capability structure. That is Host Bridge and Switches that have been enabled so far. Now, add decoder support to the 'endpoint' CXL Ports registered by the cxl_mem driver. They mostly share the same enumeration as Bridges and Switches, but witout a target list. The target of endpoint decode is device-internal DPA space, not another downstream port. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> [djbw: clarify changelog, hookup enumeration in the port driver] Link: https://lore.kernel.org/r/164386092069.765089.14895687988217608642.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-02-08cxl/core: Move target_list out of base decoder attributesDan Williams1-1/+2
In preparation for introducing endpoint decoder objects, move the target_list attribute out of the common set since it has no meaning for endpoint decoders. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/164298430100.3018233.4715072508880290970.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
generated by cgit v1.2.3 (git 2.39.1) at 2024-08-07 15:59:49 +0000