Merge tag 'cxl-for-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

Pull CXL (Compute Express Link) updates from Dan Williams:
 "The bulk of this update is support for enumerating the performance
  capabilities of CXL memory targets and connecting that to a platform
  CXL memory QoS class. Some follow-on work remains to hook up this data
  into core-mm policy, but that is saved for v6.9.

  The next significant update is unifying how CXL event records (things
  like background scrub errors) are processed between so called
  "firmware first" and native error record retrieval. The CXL driver
  handler that processes the record retrieved from the device mailbox is
  now the handler for that same record format coming from an EFI/ACPI
  notification source.

  This also contains miscellaneous feature updates, like Get Timestamp,
  and other fixups.

  Summary:

   - Add support for parsing the Coherent Device Attribute Table (CDAT)

   - Add support for calculating a platform CXL QoS class from CDAT data

   - Unify the tracing of EFI CXL Events with native CXL Events.

   - Add Get Timestamp support

   - Miscellaneous cleanups and fixups"

* tag 'cxl-for-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (41 commits)
  cxl/core: use sysfs_emit() for attr's _show()
  cxl/pci: Register for and process CPER events
  PCI: Introduce cleanup helpers for device reference counts and locks
  acpi/ghes: Process CXL Component Events
  cxl/events: Create a CXL event union
  cxl/events: Separate UUID from event structures
  cxl/events: Remove passing a UUID to known event traces
  cxl/events: Create common event UUID defines
  cxl/events: Promote CXL event structures to a core header
  cxl: Refactor to use __free() for cxl_root allocation in cxl_endpoint_port_probe()
  cxl: Refactor to use __free() for cxl_root allocation in cxl_find_nvdimm_bridge()
  cxl: Fix device reference leak in cxl_port_perf_data_calculate()
  cxl: Convert find_cxl_root() to return a 'struct cxl_root *'
  cxl: Introduce put_cxl_root() helper
  cxl/port: Fix missing target list lock
  cxl/port: Fix decoder initialization when nr_targets > interleave_ways
  cxl/region: fix x9 interleave typo
  cxl/trace: Pass UUID explicitly to event traces
  cxl/region: use %pap format to print resource_size_t
  cxl/region: Add dev_dbg() detail on failure to allocate HPA space
  ...

1 files changed, 521 insertions, 0 deletions

diff --git a/drivers/cxl/core/cdat.c b/drivers/cxl/core/cdat.c
new file mode 100644
index 000000000000..6fe11546889f
--- /dev/null
+++ b/drivers/cxl/core/cdat.c
@@ -0,0 +1,521 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2023 Intel Corporation. All rights reserved. */
+#include <linux/acpi.h>
+#include <linux/xarray.h>
+#include <linux/fw_table.h>
+#include <linux/node.h>
+#include <linux/overflow.h>
+#include "cxlpci.h"
+#include "cxlmem.h"
+#include "core.h"
+#include "cxl.h"
+
+struct dsmas_entry {
+	struct range dpa_range;
+	u8 handle;
+	struct access_coordinate coord;
+
+	int entries;
+	int qos_class;
+};
+
+static int cdat_dsmas_handler(union acpi_subtable_headers *header, void *arg,
+			      const unsigned long end)
+{
+	struct acpi_cdat_header *hdr = &header->cdat;
+	struct acpi_cdat_dsmas *dsmas;
+	int size = sizeof(*hdr) + sizeof(*dsmas);
+	struct xarray *dsmas_xa = arg;
+	struct dsmas_entry *dent;
+	u16 len;
+	int rc;
+
+	len = le16_to_cpu((__force __le16)hdr->length);
+	if (len != size || (unsigned long)hdr + len > end) {
+		pr_warn("Malformed DSMAS table length: (%u:%u)\n", size, len);
+		return -EINVAL;
+	}
+
+	/* Skip common header */
+	dsmas = (struct acpi_cdat_dsmas *)(hdr + 1);
+
+	dent = kzalloc(sizeof(*dent), GFP_KERNEL);
+	if (!dent)
+		return -ENOMEM;
+
+	dent->handle = dsmas->dsmad_handle;
+	dent->dpa_range.start = le64_to_cpu((__force __le64)dsmas->dpa_base_address);
+	dent->dpa_range.end = le64_to_cpu((__force __le64)dsmas->dpa_base_address) +
+			      le64_to_cpu((__force __le64)dsmas->dpa_length) - 1;
+
+	rc = xa_insert(dsmas_xa, dent->handle, dent, GFP_KERNEL);
+	if (rc) {
+		kfree(dent);
+		return rc;
+	}
+
+	return 0;
+}
+
+static void cxl_access_coordinate_set(struct access_coordinate *coord,
+				      int access, unsigned int val)
+{
+	switch (access) {
+	case ACPI_HMAT_ACCESS_LATENCY:
+		coord->read_latency = val;
+		coord->write_latency = val;
+		break;
+	case ACPI_HMAT_READ_LATENCY:
+		coord->read_latency = val;
+		break;
+	case ACPI_HMAT_WRITE_LATENCY:
+		coord->write_latency = val;
+		break;
+	case ACPI_HMAT_ACCESS_BANDWIDTH:
+		coord->read_bandwidth = val;
+		coord->write_bandwidth = val;
+		break;
+	case ACPI_HMAT_READ_BANDWIDTH:
+		coord->read_bandwidth = val;
+		break;
+	case ACPI_HMAT_WRITE_BANDWIDTH:
+		coord->write_bandwidth = val;
+		break;
+	}
+}
+
+static int cdat_dslbis_handler(union acpi_subtable_headers *header, void *arg,
+			       const unsigned long end)
+{
+	struct acpi_cdat_header *hdr = &header->cdat;
+	struct acpi_cdat_dslbis *dslbis;
+	int size = sizeof(*hdr) + sizeof(*dslbis);
+	struct xarray *dsmas_xa = arg;
+	struct dsmas_entry *dent;
+	__le64 le_base;
+	__le16 le_val;
+	u64 val;
+	u16 len;
+	int rc;
+
+	len = le16_to_cpu((__force __le16)hdr->length);
+	if (len != size || (unsigned long)hdr + len > end) {
+		pr_warn("Malformed DSLBIS table length: (%u:%u)\n", size, len);
+		return -EINVAL;
+	}
+
+	/* Skip common header */
+	dslbis = (struct acpi_cdat_dslbis *)(hdr + 1);
+
+	/* Skip unrecognized data type */
+	if (dslbis->data_type > ACPI_HMAT_WRITE_BANDWIDTH)
+		return 0;
+
+	/* Not a memory type, skip */
+	if ((dslbis->flags & ACPI_HMAT_MEMORY_HIERARCHY) != ACPI_HMAT_MEMORY)
+		return 0;
+
+	dent = xa_load(dsmas_xa, dslbis->handle);
+	if (!dent) {
+		pr_warn("No matching DSMAS entry for DSLBIS entry.\n");
+		return 0;
+	}
+
+	le_base = (__force __le64)dslbis->entry_base_unit;
+	le_val = (__force __le16)dslbis->entry[0];
+	rc = check_mul_overflow(le64_to_cpu(le_base),
+				le16_to_cpu(le_val), &val);
+	if (rc)
+		pr_warn("DSLBIS value overflowed.\n");
+
+	cxl_access_coordinate_set(&dent->coord, dslbis->data_type, val);
+
+	return 0;
+}
+
+static int cdat_table_parse_output(int rc)
+{
+	if (rc < 0)
+		return rc;
+	if (rc == 0)
+		return -ENOENT;
+
+	return 0;
+}
+
+static int cxl_cdat_endpoint_process(struct cxl_port *port,
+				     struct xarray *dsmas_xa)
+{
+	int rc;
+
+	rc = cdat_table_parse(ACPI_CDAT_TYPE_DSMAS, cdat_dsmas_handler,
+			      dsmas_xa, port->cdat.table);
+	rc = cdat_table_parse_output(rc);
+	if (rc)
+		return rc;
+
+	rc = cdat_table_parse(ACPI_CDAT_TYPE_DSLBIS, cdat_dslbis_handler,
+			      dsmas_xa, port->cdat.table);
+	return cdat_table_parse_output(rc);
+}
+
+static int cxl_port_perf_data_calculate(struct cxl_port *port,
+					struct xarray *dsmas_xa)
+{
+	struct access_coordinate c;
+	struct dsmas_entry *dent;
+	int valid_entries = 0;
+	unsigned long index;
+	int rc;
+
+	rc = cxl_endpoint_get_perf_coordinates(port, &c);
+	if (rc) {
+		dev_dbg(&port->dev, "Failed to retrieve perf coordinates.\n");
+		return rc;
+	}
+
+	struct cxl_root *cxl_root __free(put_cxl_root) = find_cxl_root(port);
+
+	if (!cxl_root)
+		return -ENODEV;
+
+	if (!cxl_root->ops || !cxl_root->ops->qos_class)
+		return -EOPNOTSUPP;
+
+	xa_for_each(dsmas_xa, index, dent) {
+		int qos_class;
+
+		dent->coord.read_latency = dent->coord.read_latency +
+					   c.read_latency;
+		dent->coord.write_latency = dent->coord.write_latency +
+					    c.write_latency;
+		dent->coord.read_bandwidth = min_t(int, c.read_bandwidth,
+						   dent->coord.read_bandwidth);
+		dent->coord.write_bandwidth = min_t(int, c.write_bandwidth,
+						    dent->coord.write_bandwidth);
+
+		dent->entries = 1;
+		rc = cxl_root->ops->qos_class(cxl_root, &dent->coord, 1,
+					      &qos_class);
+		if (rc != 1)
+			continue;
+
+		valid_entries++;
+		dent->qos_class = qos_class;
+	}
+
+	if (!valid_entries)
+		return -ENOENT;
+
+	return 0;
+}
+
+static void add_perf_entry(struct device *dev, struct dsmas_entry *dent,
+			   struct list_head *list)
+{
+	struct cxl_dpa_perf *dpa_perf;
+
+	dpa_perf = kzalloc(sizeof(*dpa_perf), GFP_KERNEL);
+	if (!dpa_perf)
+		return;
+
+	dpa_perf->dpa_range = dent->dpa_range;
+	dpa_perf->coord = dent->coord;
+	dpa_perf->qos_class = dent->qos_class;
+	list_add_tail(&dpa_perf->list, list);
+	dev_dbg(dev,
+		"DSMAS: dpa: %#llx qos: %d read_bw: %d write_bw %d read_lat: %d write_lat: %d\n",
+		dent->dpa_range.start, dpa_perf->qos_class,
+		dent->coord.read_bandwidth, dent->coord.write_bandwidth,
+		dent->coord.read_latency, dent->coord.write_latency);
+}
+
+static void free_perf_ents(void *data)
+{
+	struct cxl_memdev_state *mds = data;
+	struct cxl_dpa_perf *dpa_perf, *n;
+	LIST_HEAD(discard);
+
+	list_splice_tail_init(&mds->ram_perf_list, &discard);
+	list_splice_tail_init(&mds->pmem_perf_list, &discard);
+	list_for_each_entry_safe(dpa_perf, n, &discard, list) {
+		list_del(&dpa_perf->list);
+		kfree(dpa_perf);
+	}
+}
+
+static void cxl_memdev_set_qos_class(struct cxl_dev_state *cxlds,
+				     struct xarray *dsmas_xa)
+{
+	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlds);
+	struct device *dev = cxlds->dev;
+	struct range pmem_range = {
+		.start = cxlds->pmem_res.start,
+		.end = cxlds->pmem_res.end,
+	};
+	struct range ram_range = {
+		.start = cxlds->ram_res.start,
+		.end = cxlds->ram_res.end,
+	};
+	struct dsmas_entry *dent;
+	unsigned long index;
+
+	xa_for_each(dsmas_xa, index, dent) {
+		if (resource_size(&cxlds->ram_res) &&
+		    range_contains(&ram_range, &dent->dpa_range))
+			add_perf_entry(dev, dent, &mds->ram_perf_list);
+		else if (resource_size(&cxlds->pmem_res) &&
+			 range_contains(&pmem_range, &dent->dpa_range))
+			add_perf_entry(dev, dent, &mds->pmem_perf_list);
+		else
+			dev_dbg(dev, "no partition for dsmas dpa: %#llx\n",
+				dent->dpa_range.start);
+	}
+
+	devm_add_action_or_reset(&cxlds->cxlmd->dev, free_perf_ents, mds);
+}
+
+static int match_cxlrd_qos_class(struct device *dev, void *data)
+{
+	int dev_qos_class = *(int *)data;
+	struct cxl_root_decoder *cxlrd;
+
+	if (!is_root_decoder(dev))
+		return 0;
+
+	cxlrd = to_cxl_root_decoder(dev);
+	if (cxlrd->qos_class == CXL_QOS_CLASS_INVALID)
+		return 0;
+
+	if (cxlrd->qos_class == dev_qos_class)
+		return 1;
+
+	return 0;
+}
+
+static void cxl_qos_match(struct cxl_port *root_port,
+			  struct list_head *work_list,
+			  struct list_head *discard_list)
+{
+	struct cxl_dpa_perf *dpa_perf, *n;
+
+	list_for_each_entry_safe(dpa_perf, n, work_list, list) {
+		int rc;
+
+		if (dpa_perf->qos_class == CXL_QOS_CLASS_INVALID)
+			return;
+
+		rc = device_for_each_child(&root_port->dev,
+					   (void *)&dpa_perf->qos_class,
+					   match_cxlrd_qos_class);
+		if (!rc)
+			list_move_tail(&dpa_perf->list, discard_list);
+	}
+}
+
+static int match_cxlrd_hb(struct device *dev, void *data)
+{
+	struct device *host_bridge = data;
+	struct cxl_switch_decoder *cxlsd;
+	struct cxl_root_decoder *cxlrd;
+
+	if (!is_root_decoder(dev))
+		return 0;
+
+	cxlrd = to_cxl_root_decoder(dev);
+	cxlsd = &cxlrd->cxlsd;
+
+	guard(rwsem_read)(&cxl_region_rwsem);
+	for (int i = 0; i < cxlsd->nr_targets; i++) {
+		if (host_bridge == cxlsd->target[i]->dport_dev)
+			return 1;
+	}
+
+	return 0;
+}
+
+static void discard_dpa_perf(struct list_head *list)
+{
+	struct cxl_dpa_perf *dpa_perf, *n;
+
+	list_for_each_entry_safe(dpa_perf, n, list, list) {
+		list_del(&dpa_perf->list);
+		kfree(dpa_perf);
+	}
+}
+DEFINE_FREE(dpa_perf, struct list_head *, if (!list_empty(_T)) discard_dpa_perf(_T))
+
+static int cxl_qos_class_verify(struct cxl_memdev *cxlmd)
+{
+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
+	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlds);
+	LIST_HEAD(__discard);
+	struct list_head *discard __free(dpa_perf) = &__discard;
+	struct cxl_port *root_port;
+	int rc;
+
+	struct cxl_root *cxl_root __free(put_cxl_root) =
+		find_cxl_root(cxlmd->endpoint);
+
+	if (!cxl_root)
+		return -ENODEV;
+
+	root_port = &cxl_root->port;
+
+	/* Check that the QTG IDs are all sane between end device and root decoders */
+	cxl_qos_match(root_port, &mds->ram_perf_list, discard);
+	cxl_qos_match(root_port, &mds->pmem_perf_list, discard);
+
+	/* Check to make sure that the device's host bridge is under a root decoder */
+	rc = device_for_each_child(&root_port->dev,
+				   (void *)cxlmd->endpoint->host_bridge,
+				   match_cxlrd_hb);
+	if (!rc) {
+		list_splice_tail_init(&mds->ram_perf_list, discard);
+		list_splice_tail_init(&mds->pmem_perf_list, discard);
+	}
+
+	return rc;
+}
+
+static void discard_dsmas(struct xarray *xa)
+{
+	unsigned long index;
+	void *ent;
+
+	xa_for_each(xa, index, ent) {
+		xa_erase(xa, index);
+		kfree(ent);
+	}
+	xa_destroy(xa);
+}
+DEFINE_FREE(dsmas, struct xarray *, if (_T) discard_dsmas(_T))
+
+void cxl_endpoint_parse_cdat(struct cxl_port *port)
+{
+	struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport_dev);
+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
+	struct xarray __dsmas_xa;
+	struct xarray *dsmas_xa __free(dsmas) = &__dsmas_xa;
+	int rc;
+
+	xa_init(&__dsmas_xa);
+	if (!port->cdat.table)
+		return;
+
+	rc = cxl_cdat_endpoint_process(port, dsmas_xa);
+	if (rc < 0) {
+		dev_dbg(&port->dev, "Failed to parse CDAT: %d\n", rc);
+		return;
+	}
+
+	rc = cxl_port_perf_data_calculate(port, dsmas_xa);
+	if (rc) {
+		dev_dbg(&port->dev, "Failed to do perf coord calculations.\n");
+		return;
+	}
+
+	cxl_memdev_set_qos_class(cxlds, dsmas_xa);
+	cxl_qos_class_verify(cxlmd);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_endpoint_parse_cdat, CXL);
+
+static int cdat_sslbis_handler(union acpi_subtable_headers *header, void *arg,
+			       const unsigned long end)
+{
+	struct acpi_cdat_sslbis *sslbis;
+	int size = sizeof(header->cdat) + sizeof(*sslbis);
+	struct cxl_port *port = arg;
+	struct device *dev = &port->dev;
+	struct acpi_cdat_sslbe *entry;
+	int remain, entries, i;
+	u16 len;
+
+	len = le16_to_cpu((__force __le16)header->cdat.length);
+	remain = len - size;
+	if (!remain || remain % sizeof(*entry) ||
+	    (unsigned long)header + len > end) {
+		dev_warn(dev, "Malformed SSLBIS table length: (%u)\n", len);
+		return -EINVAL;
+	}
+
+	/* Skip common header */
+	sslbis = (struct acpi_cdat_sslbis *)((unsigned long)header +
+					     sizeof(header->cdat));
+
+	/* Unrecognized data type, we can skip */
+	if (sslbis->data_type > ACPI_HMAT_WRITE_BANDWIDTH)
+		return 0;
+
+	entries = remain / sizeof(*entry);
+	entry = (struct acpi_cdat_sslbe *)((unsigned long)header + sizeof(*sslbis));
+
+	for (i = 0; i < entries; i++) {
+		u16 x = le16_to_cpu((__force __le16)entry->portx_id);
+		u16 y = le16_to_cpu((__force __le16)entry->porty_id);
+		__le64 le_base;
+		__le16 le_val;
+		struct cxl_dport *dport;
+		unsigned long index;
+		u16 dsp_id;
+		u64 val;
+
+		switch (x) {
+		case ACPI_CDAT_SSLBIS_US_PORT:
+			dsp_id = y;
+			break;
+		case ACPI_CDAT_SSLBIS_ANY_PORT:
+			switch (y) {
+			case ACPI_CDAT_SSLBIS_US_PORT:
+				dsp_id = x;
+				break;
+			case ACPI_CDAT_SSLBIS_ANY_PORT:
+				dsp_id = ACPI_CDAT_SSLBIS_ANY_PORT;
+				break;
+			default:
+				dsp_id = y;
+				break;
+			}
+			break;
+		default:
+			dsp_id = x;
+			break;
+		}
+
+		le_base = (__force __le64)sslbis->entry_base_unit;
+		le_val = (__force __le16)entry->latency_or_bandwidth;
+
+		if (check_mul_overflow(le64_to_cpu(le_base),
+				       le16_to_cpu(le_val), &val))
+			dev_warn(dev, "SSLBIS value overflowed!\n");
+
+		xa_for_each(&port->dports, index, dport) {
+			if (dsp_id == ACPI_CDAT_SSLBIS_ANY_PORT ||
+			    dsp_id == dport->port_id)
+				cxl_access_coordinate_set(&dport->sw_coord,
+							  sslbis->data_type,
+							  val);
+		}
+
+		entry++;
+	}
+
+	return 0;
+}
+
+void cxl_switch_parse_cdat(struct cxl_port *port)
+{
+	int rc;
+
+	if (!port->cdat.table)
+		return;
+
+	rc = cdat_table_parse(ACPI_CDAT_TYPE_SSLBIS, cdat_sslbis_handler,
+			      port, port->cdat.table);
+	rc = cdat_table_parse_output(rc);
+	if (rc)
+		dev_dbg(&port->dev, "Failed to parse SSLBIS: %d\n", rc);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_switch_parse_cdat, CXL);
+
+MODULE_IMPORT_NS(CXL);