@@ -548,19 +548,37 @@ void cxl_coordinates_combine(struct access_coordinate *out,
MODULE_IMPORT_NS(CXL);
-void cxl_region_perf_data_calculate(struct cxl_region *cxlr,
- struct cxl_endpoint_decoder *cxled)
+static void cxl_bandwidth_add(struct access_coordinate *coord,
+ struct access_coordinate *c1,
+ struct access_coordinate *c2)
+{
+ for (int i = 0; i < ACCESS_COORDINATE_MAX; i++) {
+ coord[i].read_bandwidth = c1[i].read_bandwidth +
+ c2[i].read_bandwidth;
+ coord[i].write_bandwidth = c1[i].write_bandwidth +
+ c2[i].write_bandwidth;
+ }
+}
+
+static bool dpa_perf_contains(struct cxl_dpa_perf *perf,
+ struct resource *dpa_res)
{
- struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
- struct cxl_dev_state *cxlds = cxlmd->cxlds;
- struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlds);
struct range dpa = {
- .start = cxled->dpa_res->start,
- .end = cxled->dpa_res->end,
+ .start = dpa_res->start,
+ .end = dpa_res->end,
};
+
+ return range_contains(&perf->dpa_range, &dpa);
+}
+
+static struct cxl_dpa_perf *cxled_get_dpa_perf(struct cxl_endpoint_decoder *cxled,
+ enum cxl_decoder_mode mode)
+{
+ struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
+ struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds);
struct cxl_dpa_perf *perf;
- switch (cxlr->mode) {
+ switch (mode) {
case CXL_DECODER_RAM:
perf = &mds->ram_perf;
break;
@@ -568,12 +586,475 @@ void cxl_region_perf_data_calculate(struct cxl_region *cxlr,
perf = &mds->pmem_perf;
break;
default:
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (!dpa_perf_contains(perf, cxled->dpa_res))
+ return ERR_PTR(-EINVAL);
+
+ return perf;
+}
+
+/*
+ * Transient context for containing the current calculation of bandwidth when
+ * doing walking the port hierachy to deal with shared upstream link.
+ */
+struct cxl_perf_ctx {
+ struct access_coordinate coord[ACCESS_COORDINATE_MAX];
+ struct cxl_port *port;
+};
+
+/*
+ * cxl_endpoint_gather_bandwidth - collect all the endpoint bandwidth in an xarray
+ * @cxlr: CXL region for the bandwidth calculation
+ * @cxled: endpoint decoder to start on
+ * @usp_xa: (output) the xarray that collects all the bandwidth coordinates
+ * indexed by the upstream device with data of 'struct cxl_perf_ctx'.
+ * @gp_is_root: (output) bool of whether the grandparent is cxl root.
+ *
+ * Return: 0 for success or -errno
+ *
+ * Collects aggregated endpoint bandwidth and store the bandwidth in
+ * an xarray indexed by the upstream device of the switch or the RP
+ * device. Each endpoint consists the minimum of the bandwidth from DSLBIS
+ * from the endpoint CDAT, the endpoint upstream link bandwidth, and the
+ * bandwidth from the SSLBIS of the switch CDAT for the switch upstream port to
+ * the downstream port that's associated with the endpoint. If the
+ * device is directly connected to a RP, then no SSLBIS is involved.
+ */
+static int cxl_endpoint_gather_bandwidth(struct cxl_region *cxlr,
+ struct cxl_endpoint_decoder *cxled,
+ struct xarray *usp_xa,
+ bool *gp_is_root)
+{
+ struct cxl_port *endpoint = to_cxl_port(cxled->cxld.dev.parent);
+ struct cxl_port *parent_port = to_cxl_port(endpoint->dev.parent);
+ struct cxl_port *gp_port = to_cxl_port(parent_port->dev.parent);
+ struct access_coordinate pci_coord[ACCESS_COORDINATE_MAX];
+ struct access_coordinate sw_coord[ACCESS_COORDINATE_MAX];
+ struct access_coordinate ep_coord[ACCESS_COORDINATE_MAX];
+ struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
+ struct cxl_dev_state *cxlds = cxlmd->cxlds;
+ struct pci_dev *pdev = to_pci_dev(cxlds->dev);
+ struct cxl_perf_ctx *perf_ctx;
+ struct cxl_dpa_perf *perf;
+ unsigned long index;
+ void *ptr;
+ int rc;
+
+ if (cxlds->rcd)
+ return -ENODEV;
+
+ perf = cxled_get_dpa_perf(cxled, cxlr->mode);
+ if (IS_ERR(perf))
+ return PTR_ERR(perf);
+
+ gp_port = to_cxl_port(parent_port->dev.parent);
+ *gp_is_root = is_cxl_root(gp_port);
+
+ /*
+ * If the grandparent is cxl root, then index is the root port,
+ * otherwise it's the parent switch upstream device.
+ */
+ if (*gp_is_root)
+ index = (unsigned long)endpoint->parent_dport->dport_dev;
+ else
+ index = (unsigned long)parent_port->uport_dev;
+
+ perf_ctx = xa_load(usp_xa, index);
+ if (!perf_ctx) {
+ struct cxl_perf_ctx *c __free(kfree) =
+ kzalloc(sizeof(*perf_ctx), GFP_KERNEL);
+
+ if (!c)
+ return -ENOMEM;
+ ptr = xa_store(usp_xa, index, c, GFP_KERNEL);
+ if (xa_is_err(ptr))
+ return xa_err(ptr);
+ perf_ctx = no_free_ptr(c);
+ perf_ctx->port = parent_port;
+ }
+
+ /* Direct upstream link from EP bandwidth */
+ rc = cxl_pci_get_bandwidth(pdev, pci_coord);
+ if (rc < 0)
+ return rc;
+
+ /*
+ * Min of upstream link bandwidth and Endpoint CDAT bandwidth from
+ * DSLBIS.
+ */
+ cxl_coordinates_combine(ep_coord, pci_coord, perf->cdat_coord);
+
+ /*
+ * If grandparent port is root, then there's no switch involved and
+ * the endpoint is connected to a root port.
+ */
+ if (!*gp_is_root) {
+ /*
+ * Retrieve the switch SSLBIS for switch downstream port
+ * associated with the endpoint bandwidth.
+ */
+ rc = cxl_port_get_switch_dport_bandwidth(endpoint, sw_coord);
+ if (rc)
+ return rc;
+
+ /*
+ * Min of the earlier coordinates with the switch SSLBIS
+ * bandwidth
+ */
+ cxl_coordinates_combine(ep_coord, ep_coord, sw_coord);
+ }
+
+ /*
+ * Aggregate the computed bandwidth with the current aggregated bandwidth
+ * of the endpoints with the same switch upstream device or RP.
+ */
+ cxl_bandwidth_add(perf_ctx->coord, perf_ctx->coord, ep_coord);
+
+ return 0;
+}
+
+static void free_perf_xa(struct xarray *xa)
+{
+ struct cxl_perf_ctx *ctx;
+ unsigned long index;
+
+ if (!xa)
+ return;
+
+ xa_for_each(xa, index, ctx)
+ kfree(ctx);
+ xa_destroy(xa);
+ kfree(xa);
+}
+DEFINE_FREE(free_perf_xa, struct xarray *, if (_T) free_perf_xa(_T))
+
+/*
+ * cxl_switch_gather_bandwidth - collect all the bandwidth at switch level in an xarray
+ * @cxlr: The region being operated on
+ * @input_xa: xarray indexed by upstream device of a switch with data of 'struct
+ * cxl_perf_ctx'
+ * @gp_is_root: (output) bool of whether the grandparent is cxl root.
+ *
+ * Return: a xarray of resulting cxl_perf_ctx per parent switch or root port
+ * or ERR_PTR(-errno)
+ *
+ * Iterate through the xarray. Take the minimum of the downstream calculated
+ * bandwidth, the upstream link bandwidth, and the SSLBIS of the upstream
+ * switch if exists. Sum the resulting bandwidth under the switch upstream
+ * device or a RP device. The function can be iterated over multiple switches
+ * if the switches are present.
+ */
+static struct xarray *cxl_switch_gather_bandwidth(struct cxl_region *cxlr,
+ struct xarray *input_xa,
+ bool *gp_is_root)
+{
+ struct xarray *res_xa __free(free_perf_xa) =
+ kzalloc(sizeof(*res_xa), GFP_KERNEL);
+ struct access_coordinate coords[ACCESS_COORDINATE_MAX];
+ struct cxl_perf_ctx *ctx, *us_ctx;
+ unsigned long index, us_index;
+ int dev_count = 0;
+ int gp_count = 0;
+ void *ptr;
+ int rc;
+
+ if (!res_xa)
+ return ERR_PTR(-ENOMEM);
+ xa_init(res_xa);
+
+ xa_for_each(input_xa, index, ctx) {
+ struct device *dev = (struct device *)index;
+ struct cxl_port *port = ctx->port;
+ struct cxl_port *parent_port = to_cxl_port(port->dev.parent);
+ struct cxl_port *gp_port = to_cxl_port(parent_port->dev.parent);
+ struct cxl_dport *dport = port->parent_dport;
+ bool is_root;
+
+ dev_count++;
+ if (is_cxl_root(gp_port)) {
+ is_root = true;
+ gp_count++;
+ }
+
+ /*
+ * If the grandparent is cxl root, then index is the root port,
+ * otherwise it's the parent switch upstream device.
+ */
+ if (is_root)
+ us_index = (unsigned long)port->parent_dport->dport_dev;
+ else
+ us_index = (unsigned long)parent_port->uport_dev;
+
+ us_ctx = xa_load(res_xa, us_index);
+ if (!us_ctx) {
+ struct cxl_perf_ctx *n __free(kfree) =
+ kzalloc(sizeof(*n), GFP_KERNEL);
+
+ if (!n)
+ return ERR_PTR(-ENOMEM);
+
+ ptr = xa_store(res_xa, us_index, n, GFP_KERNEL);
+ if (xa_is_err(ptr))
+ return ERR_PTR(xa_err(ptr));
+ us_ctx = no_free_ptr(n);
+ us_ctx->port = parent_port;
+ }
+
+ /*
+ * If the device isn't an upstream PCIe port, there's something
+ * wrong with the topology.
+ */
+ if (!dev_is_pci(dev))
+ return ERR_PTR(-EINVAL);
+
+ /* Retrieve the upstream link bandwidth */
+ rc = cxl_pci_get_bandwidth(to_pci_dev(dev), coords);
+ if (rc)
+ return ERR_PTR(-ENXIO);
+
+ /*
+ * Take the min of downstream bandwidth and the upstream link
+ * bandwidth.
+ */
+ cxl_coordinates_combine(coords, coords, ctx->coord);
+
+ /*
+ * Take the min of the calculated bandwdith and the upstream
+ * switch SSLBIS bandwidth if there's a parent switch
+ */
+ if (!is_root)
+ cxl_coordinates_combine(coords, coords, dport->coord);
+
+ /*
+ * Aggregate the calculated bandwidth common to an upstream
+ * switch.
+ */
+ cxl_bandwidth_add(us_ctx->coord, us_ctx->coord, coords);
+ }
+
+ /* Asymmetric topology detected. */
+ if (gp_count) {
+ if (gp_count != dev_count) {
+ dev_dbg(&cxlr->dev,
+ "Asymmetric hierachy detected, bandwidth not updated\n");
+ return ERR_PTR(-EOPNOTSUPP);
+ }
+ *gp_is_root = true;
+ }
+
+ return no_free_ptr(res_xa);
+}
+
+/*
+ * cxl_rp_gather_bandwidth - handle the root port level bandwidth collection
+ * @xa: the xarray that holds the cxl_perf_ctx that has the bandwidth calculated
+ * below each root port device.
+ *
+ * Return: xarray that holds cxl_perf_ctx per host bridge or ERR_PTR(-errno)
+ */
+static struct xarray *cxl_rp_gather_bandwidth(struct xarray *xa)
+{
+ struct xarray *hb_xa __free(free_perf_xa) =
+ kzalloc(sizeof(*hb_xa), GFP_KERNEL);
+ struct cxl_perf_ctx *ctx;
+ unsigned long index;
+
+ if (!hb_xa)
+ return ERR_PTR(-ENOMEM);
+ xa_init(hb_xa);
+
+ xa_for_each(xa, index, ctx) {
+ struct cxl_port *port = ctx->port;
+ unsigned long hb_index = (unsigned long)port->uport_dev;
+ struct cxl_perf_ctx *hb_ctx;
+ void *ptr;
+
+ hb_ctx = xa_load(hb_xa, hb_index);
+ if (!hb_ctx) {
+ struct cxl_perf_ctx *n __free(kfree) =
+ kzalloc(sizeof(*n), GFP_KERNEL);
+
+ if (!n)
+ return ERR_PTR(-ENOMEM);
+ ptr = xa_store(hb_xa, hb_index, n, GFP_KERNEL);
+ if (xa_is_err(ptr))
+ return ERR_PTR(xa_err(ptr));
+ hb_ctx = no_free_ptr(n);
+ hb_ctx->port = port;
+ }
+
+ cxl_bandwidth_add(hb_ctx->coord, hb_ctx->coord, ctx->coord);
+ }
+
+ return no_free_ptr(hb_xa);
+}
+
+/*
+ * cxl_hb_gather_bandwidth - handle the host bridge level bandwidth collection
+ * @xa: the xarray that holds the cxl_perf_ctx that has the bandwidth calculated
+ * below each host bridge.
+ *
+ * Return: xarray that holds cxl_perf_ctx per ACPI0017 device or ERR_PTR(-errno)
+ */
+static struct xarray *cxl_hb_gather_bandwidth(struct xarray *xa)
+{
+ struct xarray *mw_xa __free(free_perf_xa) =
+ kzalloc(sizeof(*mw_xa), GFP_KERNEL);
+ struct cxl_perf_ctx *ctx;
+ unsigned long index;
+
+ if (!mw_xa)
+ return ERR_PTR(-ENOMEM);
+ xa_init(mw_xa);
+
+ xa_for_each(xa, index, ctx) {
+ struct cxl_port *port = ctx->port;
+ struct cxl_port *parent_port;
+ struct cxl_perf_ctx *mw_ctx;
+ struct cxl_dport *dport;
+ unsigned long mw_index;
+ void *ptr;
+
+ parent_port = to_cxl_port(port->dev.parent);
+ mw_index = (unsigned long)parent_port->uport_dev;
+
+ mw_ctx = xa_load(mw_xa, mw_index);
+ if (!mw_ctx) {
+ struct cxl_perf_ctx *n __free(kfree) =
+ kzalloc(sizeof(*n), GFP_KERNEL);
+
+ if (!n)
+ return ERR_PTR(-ENOMEM);
+ ptr = xa_store(mw_xa, mw_index, n, GFP_KERNEL);
+ if (xa_is_err(ptr))
+ return ERR_PTR(xa_err(ptr));
+ mw_ctx = no_free_ptr(n);
+ }
+
+ dport = port->parent_dport;
+ cxl_coordinates_combine(ctx->coord, ctx->coord, dport->coord);
+ cxl_bandwidth_add(mw_ctx->coord, mw_ctx->coord, ctx->coord);
+ }
+
+ return no_free_ptr(mw_xa);
+}
+
+/*
+ * cxl_region_update_bandwidth - Update the bandwidth access coordinates of a region
+ * @cxlr: The region being operated on
+ * @input_xa: xarray holds cxl_perf_ctx wht calculated bandwidth per ACPI0017 instance
+ */
+static void cxl_region_update_bandwidth(struct cxl_region *cxlr,
+ struct xarray *input_xa)
+{
+ struct access_coordinate coord[ACCESS_COORDINATE_MAX];
+ struct cxl_perf_ctx *ctx;
+ unsigned long index;
+
+ memset(coord, 0, sizeof(coord));
+ xa_for_each(input_xa, index, ctx)
+ cxl_bandwidth_add(coord, coord, ctx->coord);
+
+ for (int i = 0; i < ACCESS_COORDINATE_MAX; i++) {
+ cxlr->coord[i].read_bandwidth = coord[i].read_bandwidth;
+ cxlr->coord[i].write_bandwidth = coord[i].write_bandwidth;
+ }
+}
+
+/*
+ * cxl_region_shared_upstream_perf_update - Recalculate the bandwidth for the region
+ * @cxl_region: the cxl region to recalculate
+ *
+ * The function walks the topology from bottom up and calculates the bandwidth. It
+ * starts at the endpoints, processes at the switches if any, processes at the rootport
+ * level, at the host bridge level, and finally aggregates at the region.
+ */
+void cxl_region_shared_upstream_bandwidth_update(struct cxl_region *cxlr)
+{
+ struct xarray *usp_xa, *working_xa;
+ int root_count = 0;
+ bool is_root;
+ int rc;
+
+ lockdep_assert_held(&cxl_dpa_rwsem);
+
+ usp_xa = kzalloc(sizeof(*usp_xa), GFP_KERNEL);
+ if (!usp_xa)
return;
+
+ xa_init(usp_xa);
+
+ /* Collect bandwidth data from all the endpoints. */
+ for (int i = 0; i < cxlr->params.nr_targets; i++) {
+ struct cxl_endpoint_decoder *cxled = cxlr->params.targets[i];
+
+ is_root = false;
+ rc = cxl_endpoint_gather_bandwidth(cxlr, cxled, usp_xa, &is_root);
+ if (rc) {
+ free_perf_xa(usp_xa);
+ return;
+ }
+ root_count += is_root;
}
+ /* Detect asymmetric hierachy with some direct attached endpoints. */
+ if (root_count && root_count != cxlr->params.nr_targets) {
+ dev_dbg(&cxlr->dev,
+ "Asymmetric hierachy detected, bandwidth not updated\n");
+ return;
+ }
+
+ /*
+ * Walk up one or more switches to deal with the bandwidth of the
+ * switches if they exist. Endpoints directly attached to RPs skip
+ * over this part.
+ */
+ if (!root_count) {
+ do {
+ working_xa = cxl_switch_gather_bandwidth(cxlr, usp_xa,
+ &is_root);
+ if (IS_ERR(working_xa))
+ goto out;
+ free_perf_xa(usp_xa);
+ usp_xa = working_xa;
+ } while (!is_root);
+ }
+
+ /* Handle the bandwidth at the root port of the hierachy */
+ working_xa = cxl_rp_gather_bandwidth(usp_xa);
+ if (rc)
+ goto out;
+ free_perf_xa(usp_xa);
+ usp_xa = working_xa;
+
+ /* Handle the bandwidth at the host bridge of the hierachy */
+ working_xa = cxl_hb_gather_bandwidth(usp_xa);
+ if (rc)
+ goto out;
+ free_perf_xa(usp_xa);
+ usp_xa = working_xa;
+
+ /*
+ * Aggregate all the bandwidth collected per CFMWS (ACPI0017) and
+ * update the region bandwidth with the final calculated values.
+ */
+ cxl_region_update_bandwidth(cxlr, usp_xa);
+
+out:
+ free_perf_xa(usp_xa);
+}
+
+void cxl_region_perf_data_calculate(struct cxl_region *cxlr,
+ struct cxl_endpoint_decoder *cxled)
+{
+ struct cxl_dpa_perf *perf;
+
lockdep_assert_held(&cxl_dpa_rwsem);
- if (!range_contains(&perf->dpa_range, &dpa))
+ perf = cxled_get_dpa_perf(cxled, cxlr->mode);
+ if (IS_ERR(perf))
return;
for (int i = 0; i < ACCESS_COORDINATE_MAX; i++) {
@@ -103,9 +103,11 @@ enum cxl_poison_trace_type {
};
long cxl_pci_get_latency(struct pci_dev *pdev);
-
+int cxl_pci_get_bandwidth(struct pci_dev *pdev, struct access_coordinate *c);
int cxl_update_hmat_access_coordinates(int nid, struct cxl_region *cxlr,
enum access_coordinate_class access);
bool cxl_need_node_perf_attrs_update(int nid);
+int cxl_port_get_switch_dport_bandwidth(struct cxl_port *port,
+ struct access_coordinate *c);
#endif /* __CXL_CORE_H__ */
@@ -1074,3 +1074,26 @@ bool cxl_endpoint_decoder_reset_detected(struct cxl_port *port)
__cxl_endpoint_decoder_reset_detected);
}
EXPORT_SYMBOL_NS_GPL(cxl_endpoint_decoder_reset_detected, CXL);
+
+int cxl_pci_get_bandwidth(struct pci_dev *pdev, struct access_coordinate *c)
+{
+ int speed, bw;
+ u16 lnksta;
+ u32 width;
+
+ speed = pcie_link_speed_mbps(pdev);
+ if (speed < 0)
+ return speed;
+ speed /= BITS_PER_BYTE;
+
+ pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnksta);
+ width = FIELD_GET(PCI_EXP_LNKSTA_NLW, lnksta);
+ bw = speed * width;
+
+ for (int i = 0; i < ACCESS_COORDINATE_MAX; i++) {
+ c[i].read_bandwidth = bw;
+ c[i].write_bandwidth = bw;
+ }
+
+ return 0;
+}
@@ -2259,6 +2259,26 @@ int cxl_endpoint_get_perf_coordinates(struct cxl_port *port,
}
EXPORT_SYMBOL_NS_GPL(cxl_endpoint_get_perf_coordinates, CXL);
+int cxl_port_get_switch_dport_bandwidth(struct cxl_port *port,
+ struct access_coordinate *c)
+{
+ struct cxl_dport *dport = port->parent_dport;
+
+ /* Check this port is connected to a switch DSP and not an RP */
+ if (parent_port_is_cxl_root(to_cxl_port(port->dev.parent)))
+ return -ENODEV;
+
+ if (!coordinates_valid(dport->coord))
+ return -EINVAL;
+
+ for (int i = 0; i < ACCESS_COORDINATE_MAX; i++) {
+ c[i].read_bandwidth = dport->coord[i].read_bandwidth;
+ c[i].write_bandwidth = dport->coord[i].write_bandwidth;
+ }
+
+ return 0;
+}
+
/* for user tooling to ensure port disable work has completed */
static ssize_t flush_store(const struct bus_type *bus, const char *buf, size_t count)
{
@@ -1897,6 +1897,7 @@ static int cxl_region_attach(struct cxl_region *cxlr,
* then the region is already committed.
*/
p->state = CXL_CONFIG_COMMIT;
+ cxl_region_shared_upstream_bandwidth_update(cxlr);
return 0;
}
@@ -1918,6 +1919,7 @@ static int cxl_region_attach(struct cxl_region *cxlr,
if (rc)
return rc;
p->state = CXL_CONFIG_ACTIVE;
+ cxl_region_shared_upstream_bandwidth_update(cxlr);
}
cxled->cxld.interleave_ways = p->interleave_ways;
@@ -891,6 +891,7 @@ int cxl_endpoint_get_perf_coordinates(struct cxl_port *port,
struct access_coordinate *coord);
void cxl_region_perf_data_calculate(struct cxl_region *cxlr,
struct cxl_endpoint_decoder *cxled);
+void cxl_region_shared_upstream_bandwidth_update(struct cxl_region *cxlr);
void cxl_memdev_update_perf(struct cxl_memdev *cxlmd);