tools/counter: Create Counter tools
authorWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Wed, 29 Sep 2021 03:16:01 +0000 (12:16 +0900)
committerJonathan Cameron <Jonathan.Cameron@huawei.com>
Sun, 17 Oct 2021 09:54:16 +0000 (10:54 +0100)
This creates an example Counter program under tools/counter/*
to exemplify the Counter character device interface.

Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/7c0f975ba098952122302d258ec9ffdef04befaf.1632884256.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
MAINTAINERS
tools/Makefile
tools/counter/Build [new file with mode: 0644]
tools/counter/Makefile [new file with mode: 0644]
tools/counter/counter_example.c [new file with mode: 0644]

index 8310a42abdab9a3d977ea071b95c0829ab0d3931..ec1590eba56f64fb5184c980d0b195751e4e71fd 100644 (file)
@@ -4805,6 +4805,7 @@ F:        Documentation/driver-api/generic-counter.rst
 F:     drivers/counter/
 F:     include/linux/counter.h
 F:     include/uapi/linux/counter.h
+F:     tools/counter/
 
 CP2615 I2C DRIVER
 M:     Bence Csókás <bence98@sch.bme.hu>
index 7e9d34ddd74c62b6678a92e17091f69a63792232..5da1fde03a9a319ebdf5cae9894f536ce3dfd2c9 100644 (file)
@@ -12,6 +12,7 @@ help:
        @echo '  acpi                   - ACPI tools'
        @echo '  bpf                    - misc BPF tools'
        @echo '  cgroup                 - cgroup tools'
+       @echo '  counter                - counter tools'
        @echo '  cpupower               - a tool for all things x86 CPU power'
        @echo '  debugging              - tools for debugging'
        @echo '  firewire               - the userspace part of nosy, an IEEE-1394 traffic sniffer'
@@ -65,7 +66,7 @@ acpi: FORCE
 cpupower: FORCE
        $(call descend,power/$@)
 
-cgroup firewire hv guest bootconfig spi usb virtio vm bpf iio gpio objtool leds wmi pci firmware debugging tracing: FORCE
+cgroup counter firewire hv guest bootconfig spi usb virtio vm bpf iio gpio objtool leds wmi pci firmware debugging tracing: FORCE
        $(call descend,$@)
 
 bpf/%: FORCE
@@ -100,7 +101,7 @@ freefall: FORCE
 kvm_stat: FORCE
        $(call descend,kvm/$@)
 
-all: acpi cgroup cpupower gpio hv firewire liblockdep \
+all: acpi cgroup counter cpupower gpio hv firewire liblockdep \
                perf selftests bootconfig spi turbostat usb \
                virtio vm bpf x86_energy_perf_policy \
                tmon freefall iio objtool kvm_stat wmi \
@@ -112,7 +113,7 @@ acpi_install:
 cpupower_install:
        $(call descend,power/$(@:_install=),install)
 
-cgroup_install firewire_install gpio_install hv_install iio_install perf_install bootconfig_install spi_install usb_install virtio_install vm_install bpf_install objtool_install wmi_install pci_install debugging_install tracing_install:
+cgroup_install counter_install firewire_install gpio_install hv_install iio_install perf_install bootconfig_install spi_install usb_install virtio_install vm_install bpf_install objtool_install wmi_install pci_install debugging_install tracing_install:
        $(call descend,$(@:_install=),install)
 
 liblockdep_install:
@@ -133,7 +134,7 @@ freefall_install:
 kvm_stat_install:
        $(call descend,kvm/$(@:_install=),install)
 
-install: acpi_install cgroup_install cpupower_install gpio_install \
+install: acpi_install cgroup_install counter_install cpupower_install gpio_install \
                hv_install firewire_install iio_install liblockdep_install \
                perf_install selftests_install turbostat_install usb_install \
                virtio_install vm_install bpf_install x86_energy_perf_policy_install \
@@ -147,7 +148,7 @@ acpi_clean:
 cpupower_clean:
        $(call descend,power/cpupower,clean)
 
-cgroup_clean hv_clean firewire_clean bootconfig_clean spi_clean usb_clean virtio_clean vm_clean wmi_clean bpf_clean iio_clean gpio_clean objtool_clean leds_clean pci_clean firmware_clean debugging_clean tracing_clean:
+cgroup_clean counter_clean hv_clean firewire_clean bootconfig_clean spi_clean usb_clean virtio_clean vm_clean wmi_clean bpf_clean iio_clean gpio_clean objtool_clean leds_clean pci_clean firmware_clean debugging_clean tracing_clean:
        $(call descend,$(@:_clean=),clean)
 
 liblockdep_clean:
@@ -181,7 +182,7 @@ freefall_clean:
 build_clean:
        $(call descend,build,clean)
 
-clean: acpi_clean cgroup_clean cpupower_clean hv_clean firewire_clean \
+clean: acpi_clean cgroup_clean counter_clean cpupower_clean hv_clean firewire_clean \
                perf_clean selftests_clean turbostat_clean bootconfig_clean spi_clean usb_clean virtio_clean \
                vm_clean bpf_clean iio_clean x86_energy_perf_policy_clean tmon_clean \
                freefall_clean build_clean libbpf_clean libsubcmd_clean liblockdep_clean \
diff --git a/tools/counter/Build b/tools/counter/Build
new file mode 100644 (file)
index 0000000..33f4a51
--- /dev/null
@@ -0,0 +1 @@
+counter_example-y += counter_example.o
diff --git a/tools/counter/Makefile b/tools/counter/Makefile
new file mode 100644 (file)
index 0000000..5ebc195
--- /dev/null
@@ -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 $(if $(OUTPUT),$(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 (file)
index 0000000..be55287
--- /dev/null
@@ -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;
+}