Merge tag 'cxl-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

Pull cxl updates from Dave Jiang:

 - Constify range_contains() input parameters to prevent changes

 - Add support for displaying RCD capabilities in sysfs to support lspci
   for CXL device

 - Downgrade warning message to debug in cxl_probe_component_regs()

 - Add support for adding a printf specifier '%pra' to emit 'struct
   range' content:
     - Add sanity tests for 'struct resource'
     - Add documentation for special case
     - Add %pra for 'struct range'
     - Add %pra usage in CXL code

 - Add preparation code for DCD support:
     - Add range_overlaps()
     - Add CDAT DSMAS table shared and read only flag in ACPICA
     - Add documentation to 'struct dev_dax_range'
     - Delay event buffer allocation in CXL PCI code until needed
     - Use guard() in cxl_dpa_set_mode()
     - Refactor create region code to consolidate common code

* tag 'cxl-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl:
  cxl/region: Refactor common create region code
  cxl/hdm: Use guard() in cxl_dpa_set_mode()
  cxl/pci: Delay event buffer allocation
  dax: Document struct dev_dax_range
  ACPI/CDAT: Add CDAT/DSMAS shared and read only flag values
  range: Add range_overlaps()
  cxl/cdat: Use %pra for dpa range outputs
  printf: Add print format (%pra) for struct range
  Documentation/printf: struct resource add start == end special case
  test printf: Add very basic struct resource tests
  cxl: downgrade a warning message to debug level in cxl_probe_component_regs()
  cxl/pci: Add sysfs attribute for CXL 1.1 device link status
  cxl/core/regs: Add rcd_pcie_cap initialization
  kernel/range: Const-ify range_contains parameters

7 files changed, 193 insertions, 47 deletions

diff --git a/drivers/cxl/core/cdat.c b/drivers/cxl/core/cdat.c
index e9cd7939c407..2a1f164db98e 100644
--- a/drivers/cxl/core/cdat.c
+++ b/drivers/cxl/core/cdat.c
@@ -247,8 +247,8 @@ static void update_perf_entry(struct device *dev, struct dsmas_entry *dent,
 	dpa_perf->dpa_range = dent->dpa_range;
 	dpa_perf->qos_class = dent->qos_class;
 	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,
+		"DSMAS: dpa: %pra qos: %d read_bw: %d write_bw %d read_lat: %d write_lat: %d\n",
+		&dent->dpa_range, dpa_perf->qos_class,
 		dent->coord[ACCESS_COORDINATE_CPU].read_bandwidth,
 		dent->coord[ACCESS_COORDINATE_CPU].write_bandwidth,
 		dent->coord[ACCESS_COORDINATE_CPU].read_latency,
@@ -279,8 +279,8 @@ static void cxl_memdev_set_qos_class(struct cxl_dev_state *cxlds,
 			 range_contains(&pmem_range, &dent->dpa_range))
 			update_perf_entry(dev, dent, &mds->pmem_perf);
 		else
-			dev_dbg(dev, "no partition for dsmas dpa: %#llx\n",
-				dent->dpa_range.start);
+			dev_dbg(dev, "no partition for dsmas dpa: %pra\n",
+				&dent->dpa_range);
 	}
 }
 
diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 0c62b4069ba0..800466f96a68 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -89,6 +89,11 @@ resource_size_t __rcrb_to_component(struct device *dev,
 				    enum cxl_rcrb which);
 u16 cxl_rcrb_to_aer(struct device *dev, resource_size_t rcrb);
 
+#define PCI_RCRB_CAP_LIST_ID_MASK	GENMASK(7, 0)
+#define PCI_RCRB_CAP_HDR_ID_MASK	GENMASK(7, 0)
+#define PCI_RCRB_CAP_HDR_NEXT_MASK	GENMASK(15, 8)
+#define PCI_CAP_EXP_SIZEOF		0x3c
+
 extern struct rw_semaphore cxl_dpa_rwsem;
 extern struct rw_semaphore cxl_region_rwsem;
 
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index 223c273c0cd1..ff0c96ade241 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -424,7 +424,6 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled,
 	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
 	struct cxl_dev_state *cxlds = cxlmd->cxlds;
 	struct device *dev = &cxled->cxld.dev;
-	int rc;
 
 	switch (mode) {
 	case CXL_DECODER_RAM:
@@ -435,11 +434,9 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled,
 		return -EINVAL;
 	}
 
-	down_write(&cxl_dpa_rwsem);
-	if (cxled->cxld.flags & CXL_DECODER_F_ENABLE) {
-		rc = -EBUSY;
-		goto out;
-	}
+	guard(rwsem_write)(&cxl_dpa_rwsem);
+	if (cxled->cxld.flags & CXL_DECODER_F_ENABLE)
+		return -EBUSY;
 
 	/*
 	 * Only allow modes that are supported by the current partition
@@ -447,21 +444,15 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled,
 	 */
 	if (mode == CXL_DECODER_PMEM && !resource_size(&cxlds->pmem_res)) {
 		dev_dbg(dev, "no available pmem capacity\n");
-		rc = -ENXIO;
-		goto out;
+		return -ENXIO;
 	}
 	if (mode == CXL_DECODER_RAM && !resource_size(&cxlds->ram_res)) {
 		dev_dbg(dev, "no available ram capacity\n");
-		rc = -ENXIO;
-		goto out;
+		return -ENXIO;
 	}
 
 	cxled->mode = mode;
-	rc = 0;
-out:
-	up_write(&cxl_dpa_rwsem);
-
-	return rc;
+	return 0;
 }
 
 int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size)
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index dff618c708dc..70d0a017e99c 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -2537,9 +2537,8 @@ static struct cxl_region *__create_region(struct cxl_root_decoder *cxlrd,
 	return devm_cxl_add_region(cxlrd, id, mode, CXL_DECODER_HOSTONLYMEM);
 }
 
-static ssize_t create_pmem_region_store(struct device *dev,
-					struct device_attribute *attr,
-					const char *buf, size_t len)
+static ssize_t create_region_store(struct device *dev, const char *buf,
+				   size_t len, enum cxl_decoder_mode mode)
 {
 	struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev);
 	struct cxl_region *cxlr;
@@ -2549,31 +2548,26 @@ static ssize_t create_pmem_region_store(struct device *dev,
 	if (rc != 1)
 		return -EINVAL;
 
-	cxlr = __create_region(cxlrd, CXL_DECODER_PMEM, id);
+	cxlr = __create_region(cxlrd, mode, id);
 	if (IS_ERR(cxlr))
 		return PTR_ERR(cxlr);
 
 	return len;
 }
+
+static ssize_t create_pmem_region_store(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t len)
+{
+	return create_region_store(dev, buf, len, CXL_DECODER_PMEM);
+}
 DEVICE_ATTR_RW(create_pmem_region);
 
 static ssize_t create_ram_region_store(struct device *dev,
 				       struct device_attribute *attr,
 				       const char *buf, size_t len)
 {
-	struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev);
-	struct cxl_region *cxlr;
-	int rc, id;
-
-	rc = sscanf(buf, "region%d\n", &id);
-	if (rc != 1)
-		return -EINVAL;
-
-	cxlr = __create_region(cxlrd, CXL_DECODER_RAM, id);
-	if (IS_ERR(cxlr))
-		return PTR_ERR(cxlr);
-
-	return len;
+	return create_region_store(dev, buf, len, CXL_DECODER_RAM);
 }
 DEVICE_ATTR_RW(create_ram_region);
 
diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c
index e1082e749c69..429973a2165b 100644
--- a/drivers/cxl/core/regs.c
+++ b/drivers/cxl/core/regs.c
@@ -52,7 +52,7 @@ void cxl_probe_component_regs(struct device *dev, void __iomem *base,
 	cap_array = readl(base + CXL_CM_CAP_HDR_OFFSET);
 
 	if (FIELD_GET(CXL_CM_CAP_HDR_ID_MASK, cap_array) != CM_CAP_HDR_CAP_ID) {
-		dev_err(dev,
+		dev_dbg(dev,
 			"Couldn't locate the CXL.cache and CXL.mem capability array header.\n");
 		return;
 	}
@@ -506,6 +506,62 @@ out:
 	return offset;
 }
 
+static resource_size_t cxl_rcrb_to_linkcap(struct device *dev, struct cxl_dport *dport)
+{
+	resource_size_t rcrb = dport->rcrb.base;
+	void __iomem *addr;
+	u32 cap_hdr;
+	u16 offset;
+
+	if (!request_mem_region(rcrb, SZ_4K, "CXL RCRB"))
+		return CXL_RESOURCE_NONE;
+
+	addr = ioremap(rcrb, SZ_4K);
+	if (!addr) {
+		dev_err(dev, "Failed to map region %pr\n", addr);
+		release_mem_region(rcrb, SZ_4K);
+		return CXL_RESOURCE_NONE;
+	}
+
+	offset = FIELD_GET(PCI_RCRB_CAP_LIST_ID_MASK, readw(addr + PCI_CAPABILITY_LIST));
+	cap_hdr = readl(addr + offset);
+	while ((FIELD_GET(PCI_RCRB_CAP_HDR_ID_MASK, cap_hdr)) != PCI_CAP_ID_EXP) {
+		offset = FIELD_GET(PCI_RCRB_CAP_HDR_NEXT_MASK, cap_hdr);
+		if (offset == 0 || offset > SZ_4K) {
+			offset = 0;
+			break;
+		}
+		cap_hdr = readl(addr + offset);
+	}
+
+	iounmap(addr);
+	release_mem_region(rcrb, SZ_4K);
+	if (!offset)
+		return CXL_RESOURCE_NONE;
+
+	return offset;
+}
+
+int cxl_dport_map_rcd_linkcap(struct pci_dev *pdev, struct cxl_dport *dport)
+{
+	void __iomem *dport_pcie_cap = NULL;
+	resource_size_t pos;
+	struct cxl_rcrb_info *ri;
+
+	ri = &dport->rcrb;
+	pos = cxl_rcrb_to_linkcap(&pdev->dev, dport);
+	if (pos == CXL_RESOURCE_NONE)
+		return -ENXIO;
+
+	dport_pcie_cap = devm_cxl_iomap_block(&pdev->dev,
+					      ri->base + pos,
+					      PCI_CAP_EXP_SIZEOF);
+	dport->regs.rcd_pcie_cap = dport_pcie_cap;
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_dport_map_rcd_linkcap, CXL);
+
 resource_size_t __rcrb_to_component(struct device *dev, struct cxl_rcrb_info *ri,
 				    enum cxl_rcrb which)
 {
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 5406e3ab3d4a..f6015f24ad38 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -235,6 +235,14 @@ struct cxl_regs {
 	struct_group_tagged(cxl_rch_regs, rch_regs,
 		void __iomem *dport_aer;
 	);
+
+	/*
+	 * RCD upstream port specific PCIe cap register
+	 * @pcie_cap: CXL 3.0 8.2.1.2 RCD Upstream Port RCRB
+	 */
+	struct_group_tagged(cxl_rcd_regs, rcd_regs,
+		void __iomem *rcd_pcie_cap;
+	);
 };
 
 struct cxl_reg_map {
@@ -304,6 +312,7 @@ int cxl_setup_regs(struct cxl_register_map *map);
 struct cxl_dport;
 resource_size_t cxl_rcd_component_reg_phys(struct device *dev,
 					   struct cxl_dport *dport);
+int cxl_dport_map_rcd_linkcap(struct pci_dev *pdev, struct cxl_dport *dport);
 
 #define CXL_RESOURCE_NONE ((resource_size_t) -1)
 #define CXL_TARGET_STRLEN 20
diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index 188412d45e0d..b2cb81f6d9e7 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -475,9 +475,9 @@ static bool is_cxl_restricted(struct pci_dev *pdev)
 }
 
 static int cxl_rcrb_get_comp_regs(struct pci_dev *pdev,
-				  struct cxl_register_map *map)
+				  struct cxl_register_map *map,
+				  struct cxl_dport *dport)
 {
-	struct cxl_dport *dport;
 	resource_size_t component_reg_phys;
 
 	*map = (struct cxl_register_map) {
@@ -513,11 +513,24 @@ static int cxl_pci_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
 	 * is an RCH and try to extract the Component Registers from
 	 * an RCRB.
 	 */
-	if (rc && type == CXL_REGLOC_RBI_COMPONENT && is_cxl_restricted(pdev))
-		rc = cxl_rcrb_get_comp_regs(pdev, map);
-
-	if (rc)
+	if (rc && type == CXL_REGLOC_RBI_COMPONENT && is_cxl_restricted(pdev)) {
+		struct cxl_dport *dport;
+		struct cxl_port *port __free(put_cxl_port) =
+			cxl_pci_find_port(pdev, &dport);
+		if (!port)
+			return -EPROBE_DEFER;
+
+		rc = cxl_rcrb_get_comp_regs(pdev, map, dport);
+		if (rc)
+			return rc;
+
+		rc = cxl_dport_map_rcd_linkcap(pdev, dport);
+		if (rc)
+			return rc;
+
+	} else if (rc) {
 		return rc;
+	}
 
 	return cxl_setup_regs(map);
 }
@@ -764,10 +777,6 @@ static int cxl_event_config(struct pci_host_bridge *host_bridge,
 		return 0;
 	}
 
-	rc = cxl_mem_alloc_event_buf(mds);
-	if (rc)
-		return rc;
-
 	rc = cxl_event_get_int_policy(mds, &policy);
 	if (rc)
 		return rc;
@@ -781,6 +790,10 @@ static int cxl_event_config(struct pci_host_bridge *host_bridge,
 		return -EBUSY;
 	}
 
+	rc = cxl_mem_alloc_event_buf(mds);
+	if (rc)
+		return rc;
+
 	rc = cxl_event_irqsetup(mds);
 	if (rc)
 		return rc;
@@ -807,6 +820,83 @@ static int cxl_pci_type3_init_mailbox(struct cxl_dev_state *cxlds)
 	return 0;
 }
 
+static ssize_t rcd_pcie_cap_emit(struct device *dev, u16 offset, char *buf, size_t width)
+{
+	struct cxl_dev_state *cxlds = dev_get_drvdata(dev);
+	struct cxl_memdev *cxlmd = cxlds->cxlmd;
+	struct device *root_dev;
+	struct cxl_dport *dport;
+	struct cxl_port *root __free(put_cxl_port) =
+		cxl_mem_find_port(cxlmd, &dport);
+
+	if (!root)
+		return -ENXIO;
+
+	root_dev = root->uport_dev;
+	if (!root_dev)
+		return -ENXIO;
+
+	guard(device)(root_dev);
+	if (!root_dev->driver)
+		return -ENXIO;
+
+	switch (width) {
+	case 2:
+		return sysfs_emit(buf, "%#x\n",
+				  readw(dport->regs.rcd_pcie_cap + offset));
+	case 4:
+		return sysfs_emit(buf, "%#x\n",
+				  readl(dport->regs.rcd_pcie_cap + offset));
+	default:
+		return -EINVAL;
+	}
+}
+
+static ssize_t rcd_link_cap_show(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	return rcd_pcie_cap_emit(dev, PCI_EXP_LNKCAP, buf, sizeof(u32));
+}
+static DEVICE_ATTR_RO(rcd_link_cap);
+
+static ssize_t rcd_link_ctrl_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	return rcd_pcie_cap_emit(dev, PCI_EXP_LNKCTL, buf, sizeof(u16));
+}
+static DEVICE_ATTR_RO(rcd_link_ctrl);
+
+static ssize_t rcd_link_status_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	return rcd_pcie_cap_emit(dev, PCI_EXP_LNKSTA, buf, sizeof(u16));
+}
+static DEVICE_ATTR_RO(rcd_link_status);
+
+static struct attribute *cxl_rcd_attrs[] = {
+	&dev_attr_rcd_link_cap.attr,
+	&dev_attr_rcd_link_ctrl.attr,
+	&dev_attr_rcd_link_status.attr,
+	NULL
+};
+
+static umode_t cxl_rcd_visible(struct kobject *kobj, struct attribute *a, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct pci_dev *pdev = to_pci_dev(dev);
+
+	if (is_cxl_restricted(pdev))
+		return a->mode;
+
+	return 0;
+}
+
+static struct attribute_group cxl_rcd_group = {
+	.attrs = cxl_rcd_attrs,
+	.is_visible = cxl_rcd_visible,
+};
+__ATTRIBUTE_GROUPS(cxl_rcd);
+
 static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct pci_host_bridge *host_bridge = pci_find_host_bridge(pdev->bus);
@@ -1016,6 +1106,7 @@ static struct pci_driver cxl_pci_driver = {
 	.id_table		= cxl_mem_pci_tbl,
 	.probe			= cxl_pci_probe,
 	.err_handler		= &cxl_error_handlers,
+	.dev_groups		= cxl_rcd_groups,
 	.driver	= {
 		.probe_type	= PROBE_PREFER_ASYNCHRONOUS,
 	},