Merge tag 'cxl-for-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

Pull Compute Express Link (CXL) updates from Dan Williams:
 "To date Linux has been dependent on platform-firmware to map CXL RAM
  regions and handle events / errors from devices. With this update we
  can now parse / update the CXL memory layout, and report events /
  errors from devices. This is a precursor for the CXL subsystem to
  handle the end-to-end "RAS" flow for CXL memory. i.e. the flow that
  for DDR-attached-DRAM is handled by the EDAC driver where it maps
  system physical address events to a field-replaceable-unit (FRU /
  endpoint device). In general, CXL has the potential to standardize
  what has historically been a pile of memory-controller-specific error
  handling logic.

  Another change of note is the default policy for handling RAM-backed
  device-dax instances. Previously the default access mode was "device",
  mmap(2) a device special file to access memory. The new default is
  "kmem" where the address range is assigned to the core-mm via
  add_memory_driver_managed(). This saves typical users from wondering
  why their platform memory is not visible via free(1) and stuck behind
  a device-file. At the same time it allows expert users to deploy
  policy to, for example, get dedicated access to high performance
  memory, or hide low performance memory from general purpose kernel
  allocations. This affects not only CXL, but also systems with
  high-bandwidth-memory that platform-firmware tags with the
  EFI_MEMORY_SP (special purpose) designation.

  Summary:

   - CXL RAM region enumeration: instantiate 'struct cxl_region' objects
     for platform firmware created memory regions

   - CXL RAM region provisioning: complement the existing PMEM region
     creation support with RAM region support

   - "Soft Reservation" policy change: Online (memory hot-add)
     soft-reserved memory (EFI_MEMORY_SP) by default, but still allow
     for setting aside such memory for dedicated access via device-dax.

   - CXL Events and Interrupts: Takeover CXL event handling from
     platform-firmware (ACPI calls this CXL Memory Error Reporting) and
     export CXL Events via Linux Trace Events.

   - Convey CXL _OSC results to drivers: Similar to PCI, let the CXL
     subsystem interrogate the result of CXL _OSC negotiation.

   - Emulate CXL DVSEC Range Registers as "decoders": Allow for
     first-generation devices that pre-date the definition of the CXL
     HDM Decoder Capability to translate the CXL DVSEC Range Registers
     into 'struct cxl_decoder' objects.

   - Set timestamp: Per spec, set the device timestamp in case of
     hotplug, or if platform-firwmare failed to set it.

   - General fixups: linux-next build issues, non-urgent fixes for
     pre-production hardware, unit test fixes, spelling and debug
     message improvements"

* tag 'cxl-for-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (66 commits)
  dax/kmem: Fix leak of memory-hotplug resources
  cxl/mem: Add kdoc param for event log driver state
  cxl/trace: Add serial number to trace points
  cxl/trace: Add host output to trace points
  cxl/trace: Standardize device information output
  cxl/pci: Remove locked check for dvsec_range_allowed()
  cxl/hdm: Add emulation when HDM decoders are not committed
  cxl/hdm: Create emulated cxl_hdm for devices that do not have HDM decoders
  cxl/hdm: Emulate HDM decoder from DVSEC range registers
  cxl/pci: Refactor cxl_hdm_decode_init()
  cxl/port: Export cxl_dvsec_rr_decode() to cxl_port
  cxl/pci: Break out range register decoding from cxl_hdm_decode_init()
  cxl: add RAS status unmasking for CXL
  cxl: remove unnecessary calling of pci_enable_pcie_error_reporting()
  dax/hmem: build hmem device support as module if possible
  dax: cxl: add CXL_REGION dependency
  cxl: avoid returning uninitialized error code
  cxl/pmem: Fix nvdimm registration races
  cxl/mem: Fix UAPI command comment
  cxl/uapi: Tag commands from cxl_query_cmd()
  ...

1 files changed, 150 insertions, 15 deletions

diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index 30ee680d38ff..bf00dc52fe96 100644
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -9,6 +9,8 @@
 #include <linux/pci.h>
 #include <linux/mm.h>
 #include <cxlmem.h>
+
+#include "../watermark.h"
 #include "mock.h"
 
 static int interleave_arithmetic;
@@ -618,7 +620,8 @@ static struct acpi_pci_root *mock_acpi_pci_find_root(acpi_handle handle)
 	return &mock_pci_root[host_bridge_index(adev)];
 }
 
-static struct cxl_hdm *mock_cxl_setup_hdm(struct cxl_port *port)
+static struct cxl_hdm *mock_cxl_setup_hdm(struct cxl_port *port,
+					  struct cxl_endpoint_dvsec_info *info)
 {
 	struct cxl_hdm *cxlhdm = devm_kzalloc(&port->dev, sizeof(*cxlhdm), GFP_KERNEL);
 
@@ -701,7 +704,144 @@ static int mock_decoder_reset(struct cxl_decoder *cxld)
 	return 0;
 }
 
-static int mock_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
+static void default_mock_decoder(struct cxl_decoder *cxld)
+{
+	cxld->hpa_range = (struct range){
+		.start = 0,
+		.end = -1,
+	};
+
+	cxld->interleave_ways = 1;
+	cxld->interleave_granularity = 256;
+	cxld->target_type = CXL_DECODER_EXPANDER;
+	cxld->commit = mock_decoder_commit;
+	cxld->reset = mock_decoder_reset;
+}
+
+static int first_decoder(struct device *dev, void *data)
+{
+	struct cxl_decoder *cxld;
+
+	if (!is_switch_decoder(dev))
+		return 0;
+	cxld = to_cxl_decoder(dev);
+	if (cxld->id == 0)
+		return 1;
+	return 0;
+}
+
+static void mock_init_hdm_decoder(struct cxl_decoder *cxld)
+{
+	struct acpi_cedt_cfmws *window = mock_cfmws[0];
+	struct platform_device *pdev = NULL;
+	struct cxl_endpoint_decoder *cxled;
+	struct cxl_switch_decoder *cxlsd;
+	struct cxl_port *port, *iter;
+	const int size = SZ_512M;
+	struct cxl_memdev *cxlmd;
+	struct cxl_dport *dport;
+	struct device *dev;
+	bool hb0 = false;
+	u64 base;
+	int i;
+
+	if (is_endpoint_decoder(&cxld->dev)) {
+		cxled = to_cxl_endpoint_decoder(&cxld->dev);
+		cxlmd = cxled_to_memdev(cxled);
+		WARN_ON(!dev_is_platform(cxlmd->dev.parent));
+		pdev = to_platform_device(cxlmd->dev.parent);
+
+		/* check is endpoint is attach to host-bridge0 */
+		port = cxled_to_port(cxled);
+		do {
+			if (port->uport == &cxl_host_bridge[0]->dev) {
+				hb0 = true;
+				break;
+			}
+			if (is_cxl_port(port->dev.parent))
+				port = to_cxl_port(port->dev.parent);
+			else
+				port = NULL;
+		} while (port);
+		port = cxled_to_port(cxled);
+	}
+
+	/*
+	 * The first decoder on the first 2 devices on the first switch
+	 * attached to host-bridge0 mock a fake / static RAM region. All
+	 * other decoders are default disabled. Given the round robin
+	 * assignment those devices are named cxl_mem.0, and cxl_mem.4.
+	 *
+	 * See 'cxl list -BMPu -m cxl_mem.0,cxl_mem.4'
+	 */
+	if (!hb0 || pdev->id % 4 || pdev->id > 4 || cxld->id > 0) {
+		default_mock_decoder(cxld);
+		return;
+	}
+
+	base = window->base_hpa;
+	cxld->hpa_range = (struct range) {
+		.start = base,
+		.end = base + size - 1,
+	};
+
+	cxld->interleave_ways = 2;
+	eig_to_granularity(window->granularity, &cxld->interleave_granularity);
+	cxld->target_type = CXL_DECODER_EXPANDER;
+	cxld->flags = CXL_DECODER_F_ENABLE;
+	cxled->state = CXL_DECODER_STATE_AUTO;
+	port->commit_end = cxld->id;
+	devm_cxl_dpa_reserve(cxled, 0, size / cxld->interleave_ways, 0);
+	cxld->commit = mock_decoder_commit;
+	cxld->reset = mock_decoder_reset;
+
+	/*
+	 * Now that endpoint decoder is set up, walk up the hierarchy
+	 * and setup the switch and root port decoders targeting @cxlmd.
+	 */
+	iter = port;
+	for (i = 0; i < 2; i++) {
+		dport = iter->parent_dport;
+		iter = dport->port;
+		dev = device_find_child(&iter->dev, NULL, first_decoder);
+		/*
+		 * Ancestor ports are guaranteed to be enumerated before
+		 * @port, and all ports have at least one decoder.
+		 */
+		if (WARN_ON(!dev))
+			continue;
+		cxlsd = to_cxl_switch_decoder(dev);
+		if (i == 0) {
+			/* put cxl_mem.4 second in the decode order */
+			if (pdev->id == 4)
+				cxlsd->target[1] = dport;
+			else
+				cxlsd->target[0] = dport;
+		} else
+			cxlsd->target[0] = dport;
+		cxld = &cxlsd->cxld;
+		cxld->target_type = CXL_DECODER_EXPANDER;
+		cxld->flags = CXL_DECODER_F_ENABLE;
+		iter->commit_end = 0;
+		/*
+		 * Switch targets 2 endpoints, while host bridge targets
+		 * one root port
+		 */
+		if (i == 0)
+			cxld->interleave_ways = 2;
+		else
+			cxld->interleave_ways = 1;
+		cxld->interleave_granularity = 256;
+		cxld->hpa_range = (struct range) {
+			.start = base,
+			.end = base + size - 1,
+		};
+		put_device(dev);
+	}
+}
+
+static int mock_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm,
+				       struct cxl_endpoint_dvsec_info *info)
 {
 	struct cxl_port *port = cxlhdm->port;
 	struct cxl_port *parent_port = to_cxl_port(port->dev.parent);
@@ -746,16 +886,7 @@ static int mock_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
 			cxld = &cxled->cxld;
 		}
 
-		cxld->hpa_range = (struct range) {
-			.start = 0,
-			.end = -1,
-		};
-
-		cxld->interleave_ways = min_not_zero(target_count, 1);
-		cxld->interleave_granularity = SZ_4K;
-		cxld->target_type = CXL_DECODER_EXPANDER;
-		cxld->commit = mock_decoder_commit;
-		cxld->reset = mock_decoder_reset;
+		mock_init_hdm_decoder(cxld);
 
 		if (target_count) {
 			rc = device_for_each_child(port->uport, &ctx,
@@ -1119,6 +1250,12 @@ static __init int cxl_test_init(void)
 {
 	int rc, i;
 
+	cxl_acpi_test();
+	cxl_core_test();
+	cxl_mem_test();
+	cxl_pmem_test();
+	cxl_port_test();
+
 	register_cxl_mock_ops(&cxl_mock_ops);
 
 	cxl_mock_pool = gen_pool_create(ilog2(SZ_2M), NUMA_NO_NODE);
@@ -1135,11 +1272,9 @@ static __init int cxl_test_init(void)
 	if (interleave_arithmetic == 1) {
 		cfmws_start = CFMWS_XOR_ARRAY_START;
 		cfmws_end = CFMWS_XOR_ARRAY_END;
-		dev_dbg(NULL, "cxl_test loading xor math option\n");
 	} else {
 		cfmws_start = CFMWS_MOD_ARRAY_START;
 		cfmws_end = CFMWS_MOD_ARRAY_END;
-		dev_dbg(NULL, "cxl_test loading modulo math option\n");
 	}
 
 	rc = populate_cedt();
@@ -1326,7 +1461,7 @@ static __exit void cxl_test_exit(void)
 	unregister_cxl_mock_ops(&cxl_mock_ops);
 }
 
-module_param(interleave_arithmetic, int, 0000);
+module_param(interleave_arithmetic, int, 0444);
 MODULE_PARM_DESC(interleave_arithmetic, "Modulo:0, XOR:1");
 module_init(cxl_test_init);
 module_exit(cxl_test_exit);