From af9ca6f9bb16e446a44393a797d0ae74d356a5c7 Mon Sep 17 00:00:00 2001 From: Branden Bonaby Date: Thu, 3 Oct 2019 17:01:49 -0400 Subject: drivers: hv: vmbus: Introduce latency testing Introduce user specified latency in the packet reception path By exposing the test parameters as part of the debugfs channel attributes. We will control the testing state via these attributes. Signed-off-by: Branden Bonaby Reviewed-by: Michael Kelley Signed-off-by: Sasha Levin --- drivers/hv/hv_debugfs.c | 178 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 178 insertions(+) create mode 100644 drivers/hv/hv_debugfs.c (limited to 'drivers/hv/hv_debugfs.c') diff --git a/drivers/hv/hv_debugfs.c b/drivers/hv/hv_debugfs.c new file mode 100644 index 000000000000..8a2878573582 --- /dev/null +++ b/drivers/hv/hv_debugfs.c @@ -0,0 +1,178 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Authors: + * Branden Bonaby + */ + +#include +#include +#include +#include + +#include "hyperv_vmbus.h" + +struct dentry *hv_debug_root; + +static int hv_debugfs_delay_get(void *data, u64 *val) +{ + *val = *(u32 *)data; + return 0; +} + +static int hv_debugfs_delay_set(void *data, u64 val) +{ + if (val > 1000) + return -EINVAL; + *(u32 *)data = val; + return 0; +} + +DEFINE_DEBUGFS_ATTRIBUTE(hv_debugfs_delay_fops, hv_debugfs_delay_get, + hv_debugfs_delay_set, "%llu\n"); + +static int hv_debugfs_state_get(void *data, u64 *val) +{ + *val = *(bool *)data; + return 0; +} + +static int hv_debugfs_state_set(void *data, u64 val) +{ + if (val == 1) + *(bool *)data = true; + else if (val == 0) + *(bool *)data = false; + else + return -EINVAL; + return 0; +} + +DEFINE_DEBUGFS_ATTRIBUTE(hv_debugfs_state_fops, hv_debugfs_state_get, + hv_debugfs_state_set, "%llu\n"); + +/* Setup delay files to store test values */ +static int hv_debug_delay_files(struct hv_device *dev, struct dentry *root) +{ + struct vmbus_channel *channel = dev->channel; + char *buffer = "fuzz_test_buffer_interrupt_delay"; + char *message = "fuzz_test_message_delay"; + int *buffer_val = &channel->fuzz_testing_interrupt_delay; + int *message_val = &channel->fuzz_testing_message_delay; + struct dentry *buffer_file, *message_file; + + buffer_file = debugfs_create_file(buffer, 0644, root, + buffer_val, + &hv_debugfs_delay_fops); + if (IS_ERR(buffer_file)) { + pr_debug("debugfs_hyperv: file %s not created\n", buffer); + return PTR_ERR(buffer_file); + } + + message_file = debugfs_create_file(message, 0644, root, + message_val, + &hv_debugfs_delay_fops); + if (IS_ERR(message_file)) { + pr_debug("debugfs_hyperv: file %s not created\n", message); + return PTR_ERR(message_file); + } + + return 0; +} + +/* Setup test state value for vmbus device */ +static int hv_debug_set_test_state(struct hv_device *dev, struct dentry *root) +{ + struct vmbus_channel *channel = dev->channel; + bool *state = &channel->fuzz_testing_state; + char *status = "fuzz_test_state"; + struct dentry *test_state; + + test_state = debugfs_create_file(status, 0644, root, + state, + &hv_debugfs_state_fops); + if (IS_ERR(test_state)) { + pr_debug("debugfs_hyperv: file %s not created\n", status); + return PTR_ERR(test_state); + } + + return 0; +} + +/* Bind hv device to a dentry for debugfs */ +static void hv_debug_set_dir_dentry(struct hv_device *dev, struct dentry *root) +{ + if (hv_debug_root) + dev->debug_dir = root; +} + +/* Create all test dentry's and names for fuzz testing */ +int hv_debug_add_dev_dir(struct hv_device *dev) +{ + const char *device = dev_name(&dev->device); + char *delay_name = "delay"; + struct dentry *delay, *dev_root; + int ret; + + if (!IS_ERR(hv_debug_root)) { + dev_root = debugfs_create_dir(device, hv_debug_root); + if (IS_ERR(dev_root)) { + pr_debug("debugfs_hyperv: hyperv/%s/ not created\n", + device); + return PTR_ERR(dev_root); + } + hv_debug_set_test_state(dev, dev_root); + hv_debug_set_dir_dentry(dev, dev_root); + delay = debugfs_create_dir(delay_name, dev_root); + + if (IS_ERR(delay)) { + pr_debug("debugfs_hyperv: hyperv/%s/%s/ not created\n", + device, delay_name); + return PTR_ERR(delay); + } + ret = hv_debug_delay_files(dev, delay); + + return ret; + } + pr_debug("debugfs_hyperv: hyperv/ not in root debugfs path\n"); + return PTR_ERR(hv_debug_root); +} + +/* Remove dentry associated with released hv device */ +void hv_debug_rm_dev_dir(struct hv_device *dev) +{ + if (!IS_ERR(hv_debug_root)) + debugfs_remove_recursive(dev->debug_dir); +} + +/* Remove all dentrys associated with vmbus testing */ +void hv_debug_rm_all_dir(void) +{ + debugfs_remove_recursive(hv_debug_root); +} + +/* Delay buffer/message reads on a vmbus channel */ +void hv_debug_delay_test(struct vmbus_channel *channel, enum delay delay_type) +{ + struct vmbus_channel *test_channel = channel->primary_channel ? + channel->primary_channel : + channel; + bool state = test_channel->fuzz_testing_state; + + if (state) { + if (delay_type == 0) + udelay(test_channel->fuzz_testing_interrupt_delay); + else + udelay(test_channel->fuzz_testing_message_delay); + } +} + +/* Initialize top dentry for vmbus testing */ +int hv_debug_init(void) +{ + hv_debug_root = debugfs_create_dir("hyperv", NULL); + if (IS_ERR(hv_debug_root)) { + pr_debug("debugfs_hyperv: hyperv/ not created\n"); + return PTR_ERR(hv_debug_root); + } + return 0; +} -- cgit v1.2.3