@@ -8,6 +8,58 @@
#include <linux/pci.h>
#include "cxl.h"
+static struct acpi_table_header *acpi_cedt;
+
+static struct acpi_cedt_chbs *cxl_acpi_match_chbs(struct device *dev, u32 uid)
+{
+ struct acpi_cedt_chbs *chbs, *chbs_match = NULL;
+ acpi_size len, cur = 0;
+ void *cedt_subtable;
+
+ len = acpi_cedt->length - sizeof(*acpi_cedt);
+ cedt_subtable = acpi_cedt + 1;
+
+ while (cur < len) {
+ struct acpi_cedt_header *c = cedt_subtable + cur;
+
+ if (c->type != ACPI_CEDT_TYPE_CHBS) {
+ cur += c->length;
+ continue;
+ }
+
+ chbs = cedt_subtable + cur;
+
+ if (dev_WARN_ONCE(dev, chbs->header.length < sizeof(*chbs),
+ "CHBS entry skipped: invalid length:%u\n",
+ chbs->header.length)) {
+ cur += c->length;
+ continue;
+ }
+
+ if (chbs->uid != uid) {
+ cur += c->length;
+ continue;
+ }
+
+ if (dev_WARN_ONCE(dev, chbs_match,
+ "CHBS entry skipped: duplicate UID:%u\n",
+ uid)) {
+ cur += c->length;
+ continue;
+ }
+
+ chbs_match = chbs;
+ cur += c->length;
+ }
+
+ return chbs_match ? chbs_match : ERR_PTR(-ENODEV);
+}
+
+static resource_size_t get_chbcr(struct acpi_cedt_chbs *chbs)
+{
+ return IS_ERR(chbs) ? CXL_RESOURCE_NONE : chbs->base;
+}
+
struct cxl_walk_context {
struct device *dev;
struct pci_bus *root;
@@ -50,6 +102,21 @@ static int match_add_root_ports(struct pci_dev *pdev, void *data)
return 0;
}
+static struct cxl_dport *find_dport_by_dev(struct cxl_port *port, struct device *dev)
+{
+ struct cxl_dport *dport;
+
+ device_lock(&port->dev);
+ list_for_each_entry(dport, &port->dports, list)
+ if (dport->dport == dev) {
+ device_unlock(&port->dev);
+ return dport;
+ }
+
+ device_unlock(&port->dev);
+ return NULL;
+}
+
static struct acpi_device *to_cxl_host_bridge(struct device *dev)
{
struct acpi_device *adev = to_acpi_device(dev);
@@ -71,6 +138,7 @@ static int add_host_bridge_uport(struct device *match, void *arg)
struct acpi_pci_root *pci_root;
struct cxl_walk_context ctx;
struct cxl_decoder *cxld;
+ struct cxl_dport *dport;
struct cxl_port *port;
if (!bridge)
@@ -80,8 +148,14 @@ static int add_host_bridge_uport(struct device *match, void *arg)
if (!pci_root)
return -ENXIO;
- /* TODO: fold in CEDT.CHBS retrieval */
- port = devm_cxl_add_port(host, match, CXL_RESOURCE_NONE, root_port);
+ dport = find_dport_by_dev(root_port, match);
+ if (!dport) {
+ dev_dbg(host, "host bridge expected and not found\n");
+ return -ENODEV;
+ }
+
+ port = devm_cxl_add_port(host, match, dport->component_reg_phys,
+ root_port);
if (IS_ERR(port))
return PTR_ERR(port);
dev_dbg(host, "%s: add: %s\n", dev_name(match), dev_name(&port->dev));
@@ -120,6 +194,7 @@ static int add_host_bridge_dport(struct device *match, void *arg)
int rc;
acpi_status status;
unsigned long long uid;
+ struct acpi_cedt_chbs *chbs;
struct cxl_port *root_port = arg;
struct device *host = root_port->dev.parent;
struct acpi_device *bridge = to_cxl_host_bridge(match);
@@ -135,7 +210,12 @@ static int add_host_bridge_dport(struct device *match, void *arg)
return -ENODEV;
}
- rc = cxl_add_dport(root_port, match, uid, CXL_RESOURCE_NONE);
+ chbs = cxl_acpi_match_chbs(host, uid);
+ if (IS_ERR(chbs))
+ dev_dbg(host, "No CHBS found for Host Bridge: %s\n",
+ dev_name(match));
+
+ rc = cxl_add_dport(root_port, match, uid, get_chbcr(chbs));
if (rc) {
dev_err(host, "failed to add downstream port: %s\n",
dev_name(match));
@@ -172,6 +252,7 @@ static int add_root_nvdimm_bridge(struct device *match, void *data)
static int cxl_acpi_probe(struct platform_device *pdev)
{
int rc;
+ acpi_status status;
struct cxl_port *root_port;
struct device *host = &pdev->dev;
struct acpi_device *adev = ACPI_COMPANION(host);
@@ -181,10 +262,14 @@ static int cxl_acpi_probe(struct platform_device *pdev)
return PTR_ERR(root_port);
dev_dbg(host, "add: %s\n", dev_name(&root_port->dev));
+ status = acpi_get_table(ACPI_SIG_CEDT, 0, &acpi_cedt);
+ if (ACPI_FAILURE(status))
+ return -ENXIO;
+
rc = bus_for_each_dev(adev->dev.bus, NULL, root_port,
add_host_bridge_dport);
if (rc)
- return rc;
+ goto out;
/*
* Root level scanned with host-bridge as dports, now scan host-bridges
@@ -193,11 +278,14 @@ static int cxl_acpi_probe(struct platform_device *pdev)
rc = bus_for_each_dev(adev->dev.bus, NULL, root_port,
add_host_bridge_uport);
if (rc)
- return rc;
+ goto out;
if (IS_ENABLED(CONFIG_CXL_PMEM))
rc = device_for_each_child(&root_port->dev, root_port,
add_root_nvdimm_bridge);
+
+out:
+ acpi_put_table(acpi_cedt);
if (rc < 0)
return rc;
return 0;