Re: [PATCH 2/2] interconnect: qcom: Add OSM L3 interconnect provider support

From: Sibi Sankar
Date: Wed Aug 14 2019 - 07:28:02 EST

Hey Evan,

Thanks for the review!

On 2019-08-14 02:02, Evan Green wrote:
Hi Sibi,

On Wed, Aug 7, 2019 at 4:24 AM Sibi Sankar <sibis@xxxxxxxxxxxxxx> wrote:

On some Qualcomm SoCs, Operating State Manager (OSM) controls the
resources of scaling L3 caches. Add a driver to handle bandwidth
requests to OSM L3 from CPU/GPU.

Signed-off-by: Sibi Sankar <sibis@xxxxxxxxxxxxxx>

This looks good to me, just a couple minor comments below.

---
drivers/interconnect/qcom/Kconfig | 7 +
drivers/interconnect/qcom/Makefile | 2 +
drivers/interconnect/qcom/osm-l3.c | 292 +++++++++++++++++++++++++++++
3 files changed, 301 insertions(+)
create mode 100644 drivers/interconnect/qcom/osm-l3.c

diff --git a/drivers/interconnect/qcom/Kconfig b/drivers/interconnect/qcom/Kconfig
index d5e70ebc24108..f6c2a11a1a2c9 100644
--- a/drivers/interconnect/qcom/Kconfig
+++ b/drivers/interconnect/qcom/Kconfig
@@ -5,6 +5,13 @@ config INTERCONNECT_QCOM
help
Support for Qualcomm's Network-on-Chip interconnect hardware.

+config INTERCONNECT_QCOM_OSM_L3
+ tristate "Qualcomm OSM L3 interconnect driver"
+ depends on INTERCONNECT_QCOM || COMPILE_TEST
+ help
+ Say y here to support the Operating State Manager (OSM) interconnect
+ driver which controls the scaling of L3 caches on Qualcomm SoCs.
+
config INTERCONNECT_QCOM_SDM845
tristate "Qualcomm SDM845 interconnect driver"
depends on INTERCONNECT_QCOM
diff --git a/drivers/interconnect/qcom/Makefile b/drivers/interconnect/qcom/Makefile
index 1c1cea690f922..9078af5fed109 100644
--- a/drivers/interconnect/qcom/Makefile
+++ b/drivers/interconnect/qcom/Makefile
@@ -1,5 +1,7 @@
# SPDX-License-Identifier: GPL-2.0

+icc-osm-l3-objs := osm-l3.o
qnoc-sdm845-objs := sdm845.o

+obj-$(CONFIG_INTERCONNECT_QCOM_OSM_L3) += icc-osm-l3.o
obj-$(CONFIG_INTERCONNECT_QCOM_SDM845) += qnoc-sdm845.o
diff --git a/drivers/interconnect/qcom/osm-l3.c b/drivers/interconnect/qcom/osm-l3.c
new file mode 100644
index 0000000000000..1e7dfce6f4f9b
--- /dev/null
+++ b/drivers/interconnect/qcom/osm-l3.c
@@ -0,0 +1,292 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019, The Linux Foundation. All rights reserved.
+ *
+ */
+
+#include <dt-bindings/interconnect/qcom,osm-l3.h>
+#include <dt-bindings/interconnect/qcom,sdm845.h>
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/interconnect-provider.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#define LUT_MAX_ENTRIES 40U
+#define LUT_SRC GENMASK(31, 30)
+#define LUT_L_VAL GENMASK(7, 0)
+#define LUT_ROW_SIZE 32
+#define CLK_HW_DIV 2
+
+/* Register offsets */
+#define REG_ENABLE 0x0
+#define REG_FREQ_LUT 0x110
+#define REG_PERF_STATE 0x920
+
+#define OSM_L3_MAX_LINKS 1
+
+#define to_qcom_provider(_provider) \
+ container_of(_provider, struct qcom_icc_provider, provider)
+
+enum {
+ SDM845_MASTER_OSM_L3_APPS = SLAVE_TCU + 1,
+ SDM845_MASTER_OSM_L3_GPU,
+ SDM845_SLAVE_OSM_L3,
+};
+
+struct qcom_icc_provider {

Maybe we should rename this and the ones below to avoid collisions
with drivers/interconnect/qcom/sdm845.c, even though those structures
are currently local.

sure I'll do that


+ void __iomem *base;
+ unsigned int max_state;
+ unsigned long lut_tables[LUT_MAX_ENTRIES];
+ struct icc_provider provider;
+};
+
+/**
+ * struct qcom_icc_node - Qualcomm specific interconnect nodes
+ * @name: the node name used in debugfs
+ * @links: an array of nodes where we can go next while traversing
+ * @id: a unique node identifier
+ * @num_links: the total number of @links
+ * @buswidth: width of the interconnect between a node and the bus
+ */
+struct qcom_icc_node {
+ const char *name;
+ u16 links[OSM_L3_MAX_LINKS];
+ u16 id;
+ u16 num_links;
+ u16 buswidth;
+};
+
+struct qcom_icc_desc {
+ struct qcom_icc_node **nodes;
+ size_t num_nodes;
+};
+
+#define DEFINE_QNODE(_name, _id, _buswidth, ...) \
+ static struct qcom_icc_node _name = { \
+ .name = #_name, \
+ .id = _id, \
+ .buswidth = _buswidth, \
+ .num_links = ARRAY_SIZE(((int[]){ __VA_ARGS__ })), \
+ .links = { __VA_ARGS__ }, \
+ }
+
+DEFINE_QNODE(osm_apps_l3, SDM845_MASTER_OSM_L3_APPS, 16, SDM845_SLAVE_OSM_L3);
+DEFINE_QNODE(osm_gpu_l3, SDM845_MASTER_OSM_L3_GPU, 16, SDM845_SLAVE_OSM_L3);
+DEFINE_QNODE(osm_l3, SDM845_SLAVE_OSM_L3, 16);
+
+static struct qcom_icc_node *sdm845_osm_l3_nodes[] = {
+ [MASTER_OSM_L3_APPS] = &osm_apps_l3,
+ [MASTER_OSM_L3_GPU] = &osm_gpu_l3,
+ [SLAVE_OSM_L3] = &osm_l3,
+};
+
+static struct qcom_icc_desc sdm845_osm_l3 = {
+ .nodes = sdm845_osm_l3_nodes,
+ .num_nodes = ARRAY_SIZE(sdm845_osm_l3_nodes),
+};
+
+static int qcom_icc_aggregate(struct icc_node *node, u32 avg_bw,
+ u32 peak_bw, u32 *agg_avg, u32 *agg_peak)
+{
+ *agg_avg += avg_bw;
+ *agg_peak = max_t(u32, *agg_peak, peak_bw);
+
+ return 0;
+}
+
+static int qcom_icc_set(struct icc_node *src, struct icc_node *dst)
+{
+ struct icc_provider *provider;
+ struct qcom_icc_provider *qp;
+ struct qcom_icc_node *qn;
+ struct icc_node *n;
+ unsigned int index;
+ u32 agg_peak = 0;
+ u32 agg_avg = 0;
+ u64 rate;
+
+ qn = src->data;
+ provider = src->provider;
+ qp = to_qcom_provider(provider);
+
+ list_for_each_entry(n, &provider->nodes, node_list)
+ qcom_icc_aggregate(n, n->avg_bw, n->peak_bw,
+ &agg_avg, &agg_peak);
+
+ rate = max(agg_avg, agg_peak);
+ rate = icc_units_to_bps(rate);
+ do_div(rate, qn->buswidth);
+
+ for (index = 0; index < qp->max_state; index++) {
+ if (qp->lut_tables[index] >= rate)
+ break;
+ }
+
+ writel_relaxed(index, qp->base + REG_PERF_STATE);
+
+ return 0;
+}
+
+static int qcom_osm_l3_probe(struct platform_device *pdev)
+{
+ u32 info, src, lval, i, prev_freq = 0, freq;
+ static unsigned long hw_rate, xo_rate;
+ const struct qcom_icc_desc *desc;
+ struct icc_onecell_data *data;
+ struct icc_provider *provider;
+ struct qcom_icc_node **qnodes;
+ struct qcom_icc_provider *qp;
+ struct icc_node *node;
+ size_t num_nodes;
+ struct clk *clk;
+ int ret;
+
+ clk = clk_get(&pdev->dev, "xo");
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ xo_rate = clk_get_rate(clk);
+ clk_put(clk);
+
+ clk = clk_get(&pdev->dev, "alternate");
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ hw_rate = clk_get_rate(clk) / CLK_HW_DIV;
+ clk_put(clk);
+
+ qp = devm_kzalloc(&pdev->dev, sizeof(*qp), GFP_KERNEL);
+ if (!qp)
+ return -ENOMEM;
+
+ qp->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(qp->base))
+ return PTR_ERR(qp->base);
+
+ /* HW should be in enabled state to proceed */
+ if (!(readl_relaxed(qp->base + REG_ENABLE) & 0x1)) {
+ dev_err(&pdev->dev, "error hardware not enabled\n");
+ return -ENODEV;
+ }
+
+ for (i = 0; i < LUT_MAX_ENTRIES; i++) {
+ info = readl_relaxed(qp->base + REG_FREQ_LUT +
+ i * LUT_ROW_SIZE);
+ src = FIELD_GET(LUT_SRC, info);
+ lval = FIELD_GET(LUT_L_VAL, info);
+ if (src)
+ freq = xo_rate * lval;
+ else
+ freq = hw_rate;
+
+ /*
+ * Two of the same frequencies with the same core counts means
+ * end of table
+ */
+ if (i > 0 && prev_freq == freq)
+ break;
+
+ qp->lut_tables[i] = freq;
+ prev_freq = freq;
+ }
+ qp->max_state = i;
+
+ desc = of_device_get_match_data(&pdev->dev);
+ if (!desc)
+ return -EINVAL;
+
+ qnodes = desc->nodes;
+ num_nodes = desc->num_nodes;
+
+ data = devm_kcalloc(&pdev->dev, num_nodes, sizeof(*node), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ provider = &qp->provider;
+ provider->dev = &pdev->dev;
+ provider->set = qcom_icc_set;
+ provider->aggregate = qcom_icc_aggregate;
+ provider->xlate = of_icc_xlate_onecell;
+ INIT_LIST_HEAD(&provider->nodes);
+ provider->data = data;
+
+ ret = icc_provider_add(provider);
+ if (ret) {
+ dev_err(&pdev->dev, "error adding interconnect provider\n");
+ return ret;
+ }
+
+ for (i = 0; i < num_nodes; i++) {
+ size_t j;
+
+ node = icc_node_create(qnodes[i]->id);
+ if (IS_ERR(node)) {
+ ret = PTR_ERR(node);
+ goto err;
+ }
+
+ node->name = qnodes[i]->name;
+ node->data = qnodes[i];
+ icc_node_add(node, provider);
+
+ dev_dbg(&pdev->dev, "registered node %p %s %d\n", node,
+ qnodes[i]->name, node->id);
+
+ /* populate links */
+ for (j = 0; j < qnodes[i]->num_links; j++)
+ icc_link_create(node, qnodes[i]->links[j]);
+
+ data->nodes[i] = node;
+ }
+ data->num_nodes = num_nodes;
+
+ platform_set_drvdata(pdev, qp);
+
+ return ret;
+err:
+ list_for_each_entry(node, &provider->nodes, node_list) {
+ icc_node_del(node);
+ icc_node_destroy(node->id);
+ }
+
+ icc_provider_del(provider);

I looks like you could just call qcom_osm_l3_remove() here instead of the above.

yeah



+ return ret;
+}
+
+static int qcom_osm_l3_remove(struct platform_device *pdev)
+{
+ struct qcom_icc_provider *qp = platform_get_drvdata(pdev);
+ struct icc_provider *provider = &qp->provider;
+ struct icc_node *n;
+
+ list_for_each_entry(n, &provider->nodes, node_list) {
+ icc_node_del(n);
+ icc_node_destroy(n->id);
+ }
+
+ return icc_provider_del(provider);
+}
+
+static const struct of_device_id osm_l3_of_match[] = {
+ { .compatible = "qcom,sdm845-osm-l3", .data = &sdm845_osm_l3 },
+ { },
+};
+MODULE_DEVICE_TABLE(of, osm_l3_of_match);
+
+static struct platform_driver osm_l3_driver = {
+ .probe = qcom_osm_l3_probe,
+ .remove = qcom_osm_l3_remove,
+ .driver = {
+ .name = "osm-l3",
+ .of_match_table = osm_l3_of_match,
+ },
+};
+module_platform_driver(osm_l3_driver);
+
+MODULE_DESCRIPTION("Qualcomm OSM L3 interconnect driver");
+MODULE_LICENSE("GPL v2");
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


--
-- Sibi Sankar --
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project.