diff options
| -rw-r--r-- | Documentation/driver-api/interconnect.rst | 25 | ||||
| -rw-r--r-- | drivers/interconnect/Makefile | 2 | ||||
| -rw-r--r-- | drivers/interconnect/core.c | 3 | ||||
| -rw-r--r-- | drivers/interconnect/debugfs-client.c | 168 | ||||
| -rw-r--r-- | drivers/interconnect/internal.h | 1 |
5 files changed, 198 insertions, 1 deletions
diff --git a/Documentation/driver-api/interconnect.rst b/Documentation/driver-api/interconnect.rst index 5ed4f57a6bac..a92d0f277a1f 100644 --- a/Documentation/driver-api/interconnect.rst +++ b/Documentation/driver-api/interconnect.rst @@ -113,3 +113,28 @@ through dot to generate diagrams in many graphical formats:: $ cat /sys/kernel/debug/interconnect/interconnect_graph | \ dot -Tsvg > interconnect_graph.svg + +The ``test-client`` directory provides interfaces for issuing BW requests to +any arbitrary path. Note that for safety reasons, this feature is disabled by +default without a Kconfig to enable it. Enabling it requires code changes to +``#define INTERCONNECT_ALLOW_WRITE_DEBUGFS``. Example usage:: + + cd /sys/kernel/debug/interconnect/test-client/ + + # Configure node endpoints for the path from CPU to DDR on + # qcom/sm8550. + echo chm_apps > src_node + echo ebi > dst_node + + # Get path between src_node and dst_node. This is only + # necessary after updating the node endpoints. + echo 1 > get + + # Set desired BW to 1GBps avg and 2GBps peak. + echo 1000000 > avg_bw + echo 2000000 > peak_bw + + # Vote for avg_bw and peak_bw on the latest path from "get". + # Voting for multiple paths is possible by repeating this + # process for different nodes endpoints. + echo 1 > commit diff --git a/drivers/interconnect/Makefile b/drivers/interconnect/Makefile index 5604ce351a9f..d0888babb9a1 100644 --- a/drivers/interconnect/Makefile +++ b/drivers/interconnect/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 CFLAGS_core.o := -I$(src) -icc-core-objs := core.o bulk.o +icc-core-objs := core.o bulk.o debugfs-client.o obj-$(CONFIG_INTERCONNECT) += icc-core.o obj-$(CONFIG_INTERCONNECT_IMX) += imx/ diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c index fc1461dfc61b..9e12bb5e523d 100644 --- a/drivers/interconnect/core.c +++ b/drivers/interconnect/core.c @@ -1116,6 +1116,9 @@ static int __init icc_init(void) icc_debugfs_dir, NULL, &icc_summary_fops); debugfs_create_file("interconnect_graph", 0444, icc_debugfs_dir, NULL, &icc_graph_fops); + + icc_debugfs_client_init(icc_debugfs_dir); + return 0; } diff --git a/drivers/interconnect/debugfs-client.c b/drivers/interconnect/debugfs-client.c new file mode 100644 index 000000000000..bc3fd8a7b9eb --- /dev/null +++ b/drivers/interconnect/debugfs-client.c @@ -0,0 +1,168 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved. + */ +#include <linux/debugfs.h> +#include <linux/interconnect.h> +#include <linux/platform_device.h> + +#include "internal.h" + +/* + * This can be dangerous, therefore don't provide any real compile time + * configuration option for this feature. + * People who want to use this will need to modify the source code directly. + */ +#undef INTERCONNECT_ALLOW_WRITE_DEBUGFS + +#if defined(INTERCONNECT_ALLOW_WRITE_DEBUGFS) && defined(CONFIG_DEBUG_FS) + +static LIST_HEAD(debugfs_paths); +static DEFINE_MUTEX(debugfs_lock); + +static struct platform_device *pdev; +static struct icc_path *cur_path; + +static char *src_node; +static char *dst_node; +static u32 avg_bw; +static u32 peak_bw; +static u32 tag; + +struct debugfs_path { + const char *src; + const char *dst; + struct icc_path *path; + struct list_head list; +}; + +static struct icc_path *get_path(const char *src, const char *dst) +{ + struct debugfs_path *path; + + list_for_each_entry(path, &debugfs_paths, list) { + if (!strcmp(path->src, src) && !strcmp(path->dst, dst)) + return path->path; + } + + return NULL; +} + +static int icc_get_set(void *data, u64 val) +{ + struct debugfs_path *debugfs_path; + char *src, *dst; + int ret = 0; + + mutex_lock(&debugfs_lock); + + rcu_read_lock(); + src = rcu_dereference(src_node); + dst = rcu_dereference(dst_node); + + /* + * If we've already looked up a path, then use the existing one instead + * of calling icc_get() again. This allows for updating previous BW + * votes when "get" is written to multiple times for multiple paths. + */ + cur_path = get_path(src, dst); + if (cur_path) { + rcu_read_unlock(); + goto out; + } + + src = kstrdup(src, GFP_ATOMIC); + dst = kstrdup(dst, GFP_ATOMIC); + rcu_read_unlock(); + + if (!src || !dst) { + ret = -ENOMEM; + goto err_free; + } + + cur_path = icc_get(&pdev->dev, src, dst); + if (IS_ERR(cur_path)) { + ret = PTR_ERR(cur_path); + goto err_free; + } + + debugfs_path = kzalloc(sizeof(*debugfs_path), GFP_KERNEL); + if (!debugfs_path) { + ret = -ENOMEM; + goto err_put; + } + + debugfs_path->path = cur_path; + debugfs_path->src = src; + debugfs_path->dst = dst; + list_add_tail(&debugfs_path->list, &debugfs_paths); + + goto out; + +err_put: + icc_put(cur_path); +err_free: + kfree(src); + kfree(dst); +out: + mutex_unlock(&debugfs_lock); + return ret; +} + +DEFINE_DEBUGFS_ATTRIBUTE(icc_get_fops, NULL, icc_get_set, "%llu\n"); + +static int icc_commit_set(void *data, u64 val) +{ + int ret; + + mutex_lock(&debugfs_lock); + + if (IS_ERR_OR_NULL(cur_path)) { + ret = PTR_ERR(cur_path); + goto out; + } + + icc_set_tag(cur_path, tag); + ret = icc_set_bw(cur_path, avg_bw, peak_bw); +out: + mutex_unlock(&debugfs_lock); + return ret; +} + +DEFINE_DEBUGFS_ATTRIBUTE(icc_commit_fops, NULL, icc_commit_set, "%llu\n"); + +int icc_debugfs_client_init(struct dentry *icc_dir) +{ + struct dentry *client_dir; + int ret; + + pdev = platform_device_alloc("icc-debugfs-client", PLATFORM_DEVID_NONE); + + ret = platform_device_add(pdev); + if (ret) { + pr_err("%s: failed to add platform device: %d\n", __func__, ret); + platform_device_put(pdev); + return ret; + } + + client_dir = debugfs_create_dir("test_client", icc_dir); + + debugfs_create_str("src_node", 0600, client_dir, &src_node); + debugfs_create_str("dst_node", 0600, client_dir, &dst_node); + debugfs_create_file("get", 0200, client_dir, NULL, &icc_get_fops); + debugfs_create_u32("avg_bw", 0600, client_dir, &avg_bw); + debugfs_create_u32("peak_bw", 0600, client_dir, &peak_bw); + debugfs_create_u32("tag", 0600, client_dir, &tag); + debugfs_create_file("commit", 0200, client_dir, NULL, &icc_commit_fops); + + return 0; +} + +#else + +int icc_debugfs_client_init(struct dentry *icc_dir) +{ + return 0; +} + +#endif diff --git a/drivers/interconnect/internal.h b/drivers/interconnect/internal.h index 95d6ba27bf78..3b2cfd32e449 100644 --- a/drivers/interconnect/internal.h +++ b/drivers/interconnect/internal.h @@ -42,5 +42,6 @@ struct icc_path { }; struct icc_path *icc_get(struct device *dev, const char *src, const char *dst); +int icc_debugfs_client_init(struct dentry *icc_dir); #endif |