summaryrefslogtreecommitdiff
path: root/drivers/cxl/acpi.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/cxl/acpi.c')
-rw-r--r--drivers/cxl/acpi.c132
1 files changed, 129 insertions, 3 deletions
diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
index 2034eb4ce83f..2f7de910ce57 100644
--- a/drivers/cxl/acpi.c
+++ b/drivers/cxl/acpi.c
@@ -6,6 +6,7 @@
#include <linux/kernel.h>
#include <linux/acpi.h>
#include <linux/pci.h>
+#include <linux/node.h>
#include <asm/div64.h>
#include "cxlpci.h"
#include "cxl.h"
@@ -17,6 +18,10 @@ struct cxl_cxims_data {
u64 xormaps[] __counted_by(nr_maps);
};
+static const guid_t acpi_cxl_qtg_id_guid =
+ GUID_INIT(0xF365F9A6, 0xA7DE, 0x4071,
+ 0xA6, 0x6A, 0xB4, 0x0C, 0x0B, 0x4F, 0x8E, 0x52);
+
/*
* Find a targets entry (n) in the host bridge interleave list.
* CXL Specification 3.0 Table 9-22
@@ -194,6 +199,125 @@ struct cxl_cfmws_context {
int id;
};
+/**
+ * cxl_acpi_evaluate_qtg_dsm - Retrieve QTG ids via ACPI _DSM
+ * @handle: ACPI handle
+ * @coord: performance access coordinates
+ * @entries: number of QTG IDs to return
+ * @qos_class: int array provided by caller to return QTG IDs
+ *
+ * Return: number of QTG IDs returned, or -errno for errors
+ *
+ * Issue QTG _DSM with accompanied bandwidth and latency data in order to get
+ * the QTG IDs that are suitable for the performance point in order of most
+ * suitable to least suitable. Write back array of QTG IDs and return the
+ * actual number of QTG IDs written back.
+ */
+static int
+cxl_acpi_evaluate_qtg_dsm(acpi_handle handle, struct access_coordinate *coord,
+ int entries, int *qos_class)
+{
+ union acpi_object *out_obj, *out_buf, *obj;
+ union acpi_object in_array[4] = {
+ [0].integer = { ACPI_TYPE_INTEGER, coord->read_latency },
+ [1].integer = { ACPI_TYPE_INTEGER, coord->write_latency },
+ [2].integer = { ACPI_TYPE_INTEGER, coord->read_bandwidth },
+ [3].integer = { ACPI_TYPE_INTEGER, coord->write_bandwidth },
+ };
+ union acpi_object in_obj = {
+ .package = {
+ .type = ACPI_TYPE_PACKAGE,
+ .count = 4,
+ .elements = in_array,
+ },
+ };
+ int count, pkg_entries, i;
+ u16 max_qtg;
+ int rc;
+
+ if (!entries)
+ return -EINVAL;
+
+ out_obj = acpi_evaluate_dsm(handle, &acpi_cxl_qtg_id_guid, 1, 1, &in_obj);
+ if (!out_obj)
+ return -ENXIO;
+
+ if (out_obj->type != ACPI_TYPE_PACKAGE) {
+ rc = -ENXIO;
+ goto out;
+ }
+
+ /* Check Max QTG ID */
+ obj = &out_obj->package.elements[0];
+ if (obj->type != ACPI_TYPE_INTEGER) {
+ rc = -ENXIO;
+ goto out;
+ }
+
+ max_qtg = obj->integer.value;
+
+ /* It's legal to have 0 QTG entries */
+ pkg_entries = out_obj->package.count;
+ if (pkg_entries <= 1) {
+ rc = 0;
+ goto out;
+ }
+
+ /* Retrieve QTG IDs package */
+ obj = &out_obj->package.elements[1];
+ if (obj->type != ACPI_TYPE_PACKAGE) {
+ rc = -ENXIO;
+ goto out;
+ }
+
+ pkg_entries = obj->package.count;
+ count = min(entries, pkg_entries);
+ for (i = 0; i < count; i++) {
+ u16 qtg_id;
+
+ out_buf = &obj->package.elements[i];
+ if (out_buf->type != ACPI_TYPE_INTEGER) {
+ rc = -ENXIO;
+ goto out;
+ }
+
+ qtg_id = out_buf->integer.value;
+ if (qtg_id > max_qtg)
+ pr_warn("QTG ID %u greater than MAX %u\n",
+ qtg_id, max_qtg);
+
+ qos_class[i] = qtg_id;
+ }
+ rc = count;
+
+out:
+ ACPI_FREE(out_obj);
+ return rc;
+}
+
+static int cxl_acpi_qos_class(struct cxl_port *root_port,
+ struct access_coordinate *coord, int entries,
+ int *qos_class)
+{
+ acpi_handle handle;
+ struct device *dev;
+
+ dev = root_port->uport_dev;
+
+ if (!dev_is_platform(dev))
+ return -ENODEV;
+
+ handle = ACPI_HANDLE(dev);
+ if (!handle)
+ return -ENODEV;
+
+ return cxl_acpi_evaluate_qtg_dsm(handle, coord, entries, qos_class);
+}
+
+static const struct cxl_root_ops acpi_root_ops = {
+ .qos_class = cxl_acpi_qos_class,
+};
+
static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg,
const unsigned long end)
{
@@ -656,6 +780,7 @@ static int cxl_acpi_probe(struct platform_device *pdev)
{
int rc;
struct resource *cxl_res;
+ struct cxl_root *cxl_root;
struct cxl_port *root_port;
struct device *host = &pdev->dev;
struct acpi_device *adev = ACPI_COMPANION(host);
@@ -675,9 +800,10 @@ static int cxl_acpi_probe(struct platform_device *pdev)
cxl_res->end = -1;
cxl_res->flags = IORESOURCE_MEM;
- root_port = devm_cxl_add_port(host, host, CXL_RESOURCE_NONE, NULL);
- if (IS_ERR(root_port))
- return PTR_ERR(root_port);
+ cxl_root = devm_cxl_add_root(host, &acpi_root_ops);
+ if (IS_ERR(cxl_root))
+ return PTR_ERR(cxl_root);
+ root_port = &cxl_root->port;
rc = bus_for_each_dev(adev->dev.bus, NULL, root_port,
add_host_bridge_dport);