diff options
Diffstat (limited to 'tools/counter')
| -rw-r--r-- | tools/counter/Build | 1 | ||||
| -rw-r--r-- | tools/counter/Makefile | 53 | ||||
| -rw-r--r-- | tools/counter/counter_example.c | 92 |
3 files changed, 146 insertions, 0 deletions
diff --git a/tools/counter/Build b/tools/counter/Build new file mode 100644 index 000000000..33f4a51d7 --- /dev/null +++ b/tools/counter/Build @@ -0,0 +1 @@ +counter_example-y += counter_example.o diff --git a/tools/counter/Makefile b/tools/counter/Makefile new file mode 100644 index 000000000..8843f0fa6 --- /dev/null +++ b/tools/counter/Makefile @@ -0,0 +1,53 @@ +# SPDX-License-Identifier: GPL-2.0 +include ../scripts/Makefile.include + +bindir ?= /usr/bin + +ifeq ($(srctree),) +srctree := $(patsubst %/,%,$(dir $(CURDIR))) +srctree := $(patsubst %/,%,$(dir $(srctree))) +endif + +# Do not use make's built-in rules +# (this improves performance and avoids hard-to-debug behaviour); +MAKEFLAGS += -r + +override CFLAGS += -O2 -Wall -g -D_GNU_SOURCE -I$(OUTPUT)include + +ALL_TARGETS := counter_example +ALL_PROGRAMS := $(patsubst %,$(OUTPUT)%,$(ALL_TARGETS)) + +all: $(ALL_PROGRAMS) + +export srctree OUTPUT CC LD CFLAGS +include $(srctree)/tools/build/Makefile.include + +# +# We need the following to be outside of kernel tree +# +$(OUTPUT)include/linux/counter.h: ../../include/uapi/linux/counter.h + mkdir -p $(OUTPUT)include/linux 2>&1 || true + ln -sf $(CURDIR)/../../include/uapi/linux/counter.h $@ + +prepare: $(OUTPUT)include/linux/counter.h + +COUNTER_EXAMPLE := $(OUTPUT)counter_example.o +$(COUNTER_EXAMPLE): prepare FORCE + $(Q)$(MAKE) $(build)=counter_example +$(OUTPUT)counter_example: $(COUNTER_EXAMPLE) + $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@ + +clean: + rm -f $(ALL_PROGRAMS) + rm -rf $(OUTPUT)include/linux/counter.h + find $(or $(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete + +install: $(ALL_PROGRAMS) + install -d -m 755 $(DESTDIR)$(bindir); \ + for program in $(ALL_PROGRAMS); do \ + install $$program $(DESTDIR)$(bindir); \ + done + +FORCE: + +.PHONY: all install clean FORCE prepare diff --git a/tools/counter/counter_example.c b/tools/counter/counter_example.c new file mode 100644 index 000000000..be55287b9 --- /dev/null +++ b/tools/counter/counter_example.c @@ -0,0 +1,92 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Counter - example userspace application + * + * The userspace application opens /dev/counter0, configures the + * COUNTER_EVENT_INDEX event channel 0 to gather Count 0 count and Count + * 1 count, and prints out the data as it becomes available on the + * character device node. + * + * Copyright (C) 2021 William Breathitt Gray + */ +#include <errno.h> +#include <fcntl.h> +#include <linux/counter.h> +#include <stdio.h> +#include <string.h> +#include <sys/ioctl.h> +#include <unistd.h> + +static struct counter_watch watches[2] = { + { + /* Component data: Count 0 count */ + .component.type = COUNTER_COMPONENT_COUNT, + .component.scope = COUNTER_SCOPE_COUNT, + .component.parent = 0, + /* Event type: Index */ + .event = COUNTER_EVENT_INDEX, + /* Device event channel 0 */ + .channel = 0, + }, + { + /* Component data: Count 1 count */ + .component.type = COUNTER_COMPONENT_COUNT, + .component.scope = COUNTER_SCOPE_COUNT, + .component.parent = 1, + /* Event type: Index */ + .event = COUNTER_EVENT_INDEX, + /* Device event channel 0 */ + .channel = 0, + }, +}; + +int main(void) +{ + int fd; + int ret; + int i; + struct counter_event event_data[2]; + + fd = open("/dev/counter0", O_RDWR); + if (fd == -1) { + perror("Unable to open /dev/counter0"); + return 1; + } + + for (i = 0; i < 2; i++) { + ret = ioctl(fd, COUNTER_ADD_WATCH_IOCTL, watches + i); + if (ret == -1) { + fprintf(stderr, "Error adding watches[%d]: %s\n", i, + strerror(errno)); + return 1; + } + } + ret = ioctl(fd, COUNTER_ENABLE_EVENTS_IOCTL); + if (ret == -1) { + perror("Error enabling events"); + return 1; + } + + for (;;) { + ret = read(fd, event_data, sizeof(event_data)); + if (ret == -1) { + perror("Failed to read event data"); + return 1; + } + + if (ret != sizeof(event_data)) { + fprintf(stderr, "Failed to read event data\n"); + return -EIO; + } + + printf("Timestamp 0: %llu\tCount 0: %llu\n" + "Error Message 0: %s\n" + "Timestamp 1: %llu\tCount 1: %llu\n" + "Error Message 1: %s\n", + event_data[0].timestamp, event_data[0].value, + strerror(event_data[0].status), + event_data[1].timestamp, event_data[1].value, + strerror(event_data[1].status)); + } + + return 0; +} |