Merge tag 'cxl-for-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

Pull CXL updates from Dave Jiang:
 "The most significant changes in this pull request is the series that
  introduces ACQUIRE() and ACQUIRE_ERR() macros to replace conditional
  locking and ease the pain points of scoped_cond_guard().

  The series also includes follow on changes that refactor the CXL
  sub-system to utilize the new macros.

  Detail summary:

   - Add documentation template for CXL conventions to document CXL
     platform quirks

   - Replace mutex_lock_io() with mutex_lock() for mailbox

   - Add location limit for fake CFMWS range for cxl_test, ARM platform
     enabling

   - CXL documentation typo and clarity fixes

   - Use correct format specifier for function cxl_set_ecs_threshold()

   - Make cxl_bus_type constant

   - Introduce new helper cxl_resource_contains_addr() to check address
     availability

   - Fix wrong DPA checking for PPR operation

   - Remove core/acpi.c and CXL core dependency on ACPI

   - Introduce ACQUIRE() and ACQUIRE_ERR() for conditional locks

   - Add CXL updates utilizing ACQUIRE() macro to remove gotos and
     improve readability

   - Add return for the dummy version of cxl_decoder_detach() without
     CONFIG_CXL_REGION

   - CXL events updates for spec r3.2

   - Fix return of __cxl_decoder_detach() error path

   - CXL debugfs documentation fix"

* tag 'cxl-for-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (28 commits)
  Documentation/ABI/testing/debugfs-cxl: Add 'cxl' to clear_poison path
  cxl/region: Fix an ERR_PTR() vs NULL bug
  cxl/events: Trace Memory Sparing Event Record
  cxl/events: Add extra validity checks for CVME count in DRAM Event Record
  cxl/events: Add extra validity checks for corrected memory error count in General Media Event Record
  cxl/events: Update Common Event Record to CXL spec rev 3.2
  cxl: Fix -Werror=return-type in cxl_decoder_detach()
  cleanup: Fix documentation build error for ACQUIRE updates
  cxl: Convert to ACQUIRE() for conditional rwsem locking
  cxl/region: Consolidate cxl_decoder_kill_region() and cxl_region_detach()
  cxl/region: Move ready-to-probe state check to a helper
  cxl/region: Split commit_store() into __commit() and queue_reset() helpers
  cxl/decoder: Drop pointless locking
  cxl/decoder: Move decoder register programming to a helper
  cxl/mbox: Convert poison list mutex to ACQUIRE()
  cleanup: Introduce ACQUIRE() and ACQUIRE_ERR() for conditional locks
  cxl: Remove core/acpi.c and cxl core dependency on ACPI
  cxl/core: Using cxl_resource_contains_addr() to check address availability
  cxl/edac: Fix wrong dpa checking for PPR operation
  cxl/core: Introduce a new helper cxl_resource_contains_addr()
  ...

Author: torvalds

Documentation/ABI/testing/debugfs-cxl

@@ -20,7 +20,7 @@ Description:
 		visible for devices supporting the capability.
 
 
-What:		/sys/kernel/debug/memX/clear_poison
+What:		/sys/kernel/debug/cxl/memX/clear_poison
 Date:		April, 2023
 KernelVersion:	v6.4
 Contact:	[email protected]

Documentation/driver-api/cxl/conventions.rst

@@ -0,0 +1,47 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. include:: <isonum.txt>
+
+=======================================
+Compute Express Link: Linux Conventions
+=======================================
+
+There exists shipping platforms that bend or break CXL specification
+expectations. Record the details and the rationale for those deviations.
+Borrow the ACPI Code First template format to capture the assumptions
+and tradeoffs such that multiple platform implementations can follow the
+same convention.
+
+<(template) Title>
+==================
+
+Document
+--------
+CXL Revision <rev>, Version <ver>
+
+License
+-------
+SPDX-License Identifier: CC-BY-4.0
+
+Creator/Contributors
+--------------------
+
+Summary of the Change
+---------------------
+
+<Detail the conflict with the specification and where available the
+assumptions and tradeoffs taken by the hardware platform.>
+
+
+Benefits of the Change
+----------------------
+
+<Detail what happens if platforms and Linux do not adopt this
+convention.>
+
+References
+----------
+
+Detailed Description of the Change
+----------------------------------
+
+<Propose spec language that corrects the conflict.>

Documentation/driver-api/cxl/devices/device-types.rst

@@ -63,13 +63,13 @@ A Type-2 CXL Device:
 
 * Supports cxl.io, cxl.cache, and cxl.mem protocols
 * Optionally implements coherent cache and Host-Managed Device Memory
-* Is typically an accelerator device w/ high bandwidth memory.
+* Is typically an accelerator device with high bandwidth memory.
 
 The primary difference between a type-1 and type-2 device is the presence
 of host-managed device memory, which allows the device to operate on a
-local memory bank - while the CPU sill has coherent DMA to the same memory.
+local memory bank - while the CPU still has coherent DMA to the same memory.
 
-The allows things like GPUs to expose their memory via DAX devices or file
+This allows things like GPUs to expose their memory via DAX devices or file
 descriptors, allows drivers and programs direct access to device memory
 rather than use block-transfer semantics.
 
@@ -89,7 +89,7 @@ basic coherent DMA.
 Switch
 ------
 
-A CXL switch is a device capacity of routing any CXL (and by extension, PCIe)
+A CXL switch is a device capable of routing any CXL (and by extension, PCIe)
 protocol between an upstream, downstream, or peer devices.  Many devices, such
 as Multi-Logical Devices, imply the presence of switching in some manner.
 
@@ -103,7 +103,7 @@ A Single-Logical Device (SLD) is a device which presents a single device to
 one or more heads.
 
 A Multi-Logical Device (MLD) is a device which may present multiple devices
-to one or more devices.
+to one or more upstream devices.
 
 A Single-Headed Device exposes only a single physical connection.
 

Documentation/driver-api/cxl/index.rst

@@ -14,6 +14,7 @@ that have impacts on each other.  The docs here break up configurations steps.
 
    theory-of-operation
    maturity-map
+   conventions
 
 .. toctree::
    :maxdepth: 2

Documentation/driver-api/cxl/linux/cxl-driver.rst

@@ -20,7 +20,7 @@ The CXL driver is split into a number of drivers.
 * cxl_port  - initializes root and provides port enumeration interface.
 * cxl_acpi  - initializes root decoders and interacts with ACPI data.
 * cxl_p/mem - initializes memory devices
-* cxl_pci   - uses cxl_port to enumates the actual fabric hierarchy.
+* cxl_pci   - uses cxl_port to enumerate the actual fabric hierarchy.
 
 Driver Devices
 ==============

Documentation/driver-api/cxl/theory-of-operation.rst

@@ -29,8 +29,8 @@ Platform firmware enumerates a menu of interleave options at the "CXL root port"
 (Linux term for the top of the CXL decode topology). From there, PCIe topology
 dictates which endpoints can participate in which Host Bridge decode regimes.
 Each PCIe Switch in the path between the root and an endpoint introduces a point
-at which the interleave can be split. For example platform firmware may say at a
-given range only decodes to 1 one Host Bridge, but that Host Bridge may in turn
+at which the interleave can be split. For example, platform firmware may say a
+given range only decodes to one Host Bridge, but that Host Bridge may in turn
 interleave cycles across multiple Root Ports. An intervening Switch between a
 port and an endpoint may interleave cycles across multiple Downstream Switch
 Ports, etc.
@@ -187,7 +187,7 @@ decodes them to "ports", "ports" decode to "endpoints", and "endpoints"
 represent the decode from SPA (System Physical Address) to DPA (Device Physical
 Address).
 
-Continuing the RAID analogy, disks have both topology metadata and on device
+Continuing the RAID analogy, disks have both topology metadata and on-device
 metadata that determine RAID set assembly. CXL Port topology and CXL Port link
 status is metadata for CXL.mem set assembly. The CXL Port topology is enumerated
 by the arrival of a CXL.mem device. I.e. unless and until the PCIe core attaches
@@ -197,7 +197,7 @@ the Linux PCI core to tear down switch-level CXL resources because the endpoint
 ->remove() event cleans up the port data that was established to support that
 Memory Expander.
 
-The port metadata and potential decode schemes that a give memory device may
+The port metadata and potential decode schemes that a given memory device may
 participate can be determined via a command like::
 
     # cxl list -BDMu -d root -m mem3
@@ -249,8 +249,8 @@ participate can be determined via a command like::
 ...which queries the CXL topology to ask "given CXL Memory Expander with a kernel
 device name of 'mem3' which platform level decode ranges may this device
 participate". A given expander can participate in multiple CXL.mem interleave
-sets simultaneously depending on how many decoder resource it has. In this
-example mem3 can participate in one or more of a PMEM interleave that spans to
+sets simultaneously depending on how many decoder resources it has. In this
+example mem3 can participate in one or more of a PMEM interleave that spans two
 Host Bridges, a PMEM interleave that targets a single Host Bridge, a Volatile
 memory interleave that spans 2 Host Bridges, and a Volatile memory interleave
 that only targets a single Host Bridge.

drivers/cxl/acpi.c

@@ -335,6 +335,63 @@ static int add_or_reset_cxl_resource(struct resource *parent, struct resource *r
 	return rc;
 }
 
+static int cxl_acpi_set_cache_size(struct cxl_root_decoder *cxlrd)
+{
+	struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
+	struct range *hpa = &cxld->hpa_range;
+	resource_size_t size = range_len(hpa);
+	resource_size_t start = hpa->start;
+	resource_size_t cache_size;
+	struct resource res;
+	int nid, rc;
+
+	res = DEFINE_RES(start, size, 0);
+	nid = phys_to_target_node(start);
+
+	rc = hmat_get_extended_linear_cache_size(&res, nid, &cache_size);
+	if (rc)
+		return rc;
+
+	/*
+	 * The cache range is expected to be within the CFMWS.
+	 * Currently there is only support cache_size == cxl_size. CXL
+	 * size is then half of the total CFMWS window size.
+	 */
+	size = size >> 1;
+	if (cache_size && size != cache_size) {
+		dev_warn(&cxld->dev,
+			 "Extended Linear Cache size %pa != CXL size %pa. No Support!",
+			 &cache_size, &size);
+		return -ENXIO;
+	}
+
+	cxlrd->cache_size = cache_size;
+
+	return 0;
+}
+
+static void cxl_setup_extended_linear_cache(struct cxl_root_decoder *cxlrd)
+{
+	int rc;
+
+	rc = cxl_acpi_set_cache_size(cxlrd);
+	if (!rc)
+		return;
+
+	if (rc != -EOPNOTSUPP) {
+		/*
+		 * Failing to support extended linear cache region resize does not
+		 * prevent the region from functioning. Only causes cxl list showing
+		 * incorrect region size.
+		 */
+		dev_warn(cxlrd->cxlsd.cxld.dev.parent,
+			 "Extended linear cache calculation failed rc:%d\n", rc);
+	}
+
+	/* Ignoring return code */
+	cxlrd->cache_size = 0;
+}
+
 DEFINE_FREE(put_cxlrd, struct cxl_root_decoder *,
 	    if (!IS_ERR_OR_NULL(_T)) put_device(&_T->cxlsd.cxld.dev))
 DEFINE_FREE(del_cxl_resource, struct resource *, if (_T) del_cxl_resource(_T))
@@ -394,6 +451,8 @@ static int __cxl_parse_cfmws(struct acpi_cedt_cfmws *cfmws,
 		ig = CXL_DECODER_MIN_GRANULARITY;
 	cxld->interleave_granularity = ig;
 
+	cxl_setup_extended_linear_cache(cxlrd);
+
 	if (cfmws->interleave_arithmetic == ACPI_CEDT_CFMWS_ARITHMETIC_XOR) {
 		if (ways != 1 && ways != 3) {
 			cxims_ctx = (struct cxl_cxims_context) {

drivers/cxl/core/Makefile

@@ -15,7 +15,6 @@ cxl_core-y += hdm.o
 cxl_core-y += pmu.o
 cxl_core-y += cdat.o
 cxl_core-y += ras.o
-cxl_core-y += acpi.o
 cxl_core-$(CONFIG_TRACING) += trace.o
 cxl_core-$(CONFIG_CXL_REGION) += region.o
 cxl_core-$(CONFIG_CXL_MCE) += mce.o

drivers/cxl/core/acpi.c

@@ -336,7 +336,7 @@ static int match_cxlrd_hb(struct device *dev, void *data)
 	cxlrd = to_cxl_root_decoder(dev);
 	cxlsd = &cxlrd->cxlsd;
 
-	guard(rwsem_read)(&cxl_region_rwsem);
+	guard(rwsem_read)(&cxl_rwsem.region);
 	for (int i = 0; i < cxlsd->nr_targets; i++) {
 		if (host_bridge == cxlsd->target[i]->dport_dev)
 			return 1;
@@ -987,7 +987,7 @@ void cxl_region_shared_upstream_bandwidth_update(struct cxl_region *cxlr)
 	bool is_root;
 	int rc;
 
-	lockdep_assert_held(&cxl_dpa_rwsem);
+	lockdep_assert_held(&cxl_rwsem.dpa);
 
 	struct xarray *usp_xa __free(free_perf_xa) =
 		kzalloc(sizeof(*usp_xa), GFP_KERNEL);
@@ -1057,7 +1057,7 @@ void cxl_region_perf_data_calculate(struct cxl_region *cxlr,
 {
 	struct cxl_dpa_perf *perf;
 
-	lockdep_assert_held(&cxl_dpa_rwsem);
+	lockdep_assert_held(&cxl_rwsem.dpa);
 
 	perf = cxled_get_dpa_perf(cxled);
 	if (IS_ERR(perf))