linux-dev/drivers/cxl, branch linus/master

cxl/port: Enable HDM Capability after validating DVSEC Ranges

2022-05-20T19:30:53Z

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: fix early terminiation of range-allowed loop] Cc: Ariel Sibley [ariel: Memory_size must be non-zero] Cc: Jonathan Cameron Reviewed-by: Ira Weiny Link: https://lore.kernel.org/r/165307136375.2499769.861793697156744166.stgit@dwillia2-xfh Signed-off-by: Dan Williams

cxl/port: Reuse 'struct cxl_hdm' context for hdm init

2022-05-19T15:50:42Z

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 Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/165291691712.1426646.14336397551571515480.stgit@dwillia2-xfh Signed-off-by: Dan Williams

cxl/port: Move endpoint HDM Decoder Capability init to port driver

2022-05-19T15:50:41Z

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 Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/165291691167.1426646.7936109077255288258.stgit@dwillia2-xfh Signed-off-by: Dan Williams

cxl/pci: Drop @info argument to cxl_hdm_decode_init()

2022-05-19T15:50:41Z

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 Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/165291690612.1426646.7866084245521113414.stgit@dwillia2-xfh Signed-off-by: Dan Williams

cxl/mem: Merge cxl_dvsec_ranges() and cxl_hdm_decode_init()

2022-05-19T15:50:41Z

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 Link: https://lore.kernel.org/r/165291690027.1426646.10249756632415633752.stgit@dwillia2-xfh Signed-off-by: Dan Williams

cxl/mem: Skip range enumeration if mem_enable clear

2022-05-19T15:50:41Z

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 Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/165291689442.1426646.18012291761753694336.stgit@dwillia2-xfh Signed-off-by: Dan Williams

cxl/mem: Consolidate CXL DVSEC Range enumeration in the core

2022-05-19T15:50:41Z

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 Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/165291688886.1426646.15046138604010482084.stgit@dwillia2-xfh Signed-off-by: Dan Williams

cxl/pci: Move cxl_await_media_ready() to the core

2022-05-19T15:50:41Z

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 Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/165291688340.1426646.4755627801983775011.stgit@dwillia2-xfh Signed-off-by: Dan Williams

cxl/mem: Validate port connectivity before dvsec ranges

2022-05-19T15:50:41Z

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 Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/165291687749.1426646.18091538443879226995.stgit@dwillia2-xfh Signed-off-by: Dan Williams

cxl/mem: Fix cxl_mem_probe() error exit

2022-05-19T15:50:41Z

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 Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/165291687176.1426646.15449254938752532784.stgit@dwillia2-xfh Signed-off-by: Dan Williams