This provides a basic interface between hv_24x7 and perf. Similar to
the one provided for gpci, it lacks transaction support and does not
list any events.
Signed-off-by: Cody P Schafer <c...@linux.vnet.ibm.com>
---
arch/powerpc/perf/hv-24x7.c | 354 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 354 insertions(+)
create mode 100644 arch/powerpc/perf/hv-24x7.c
diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c
new file mode 100644
index 0000000..fb49e66
--- /dev/null
+++ b/arch/powerpc/perf/hv-24x7.c
@@ -0,0 +1,354 @@
+/*
+ * Hypervisor supplied "24x7" performance counter support
+ *
+ * Author: Cody P Schafer <c...@linux.vnet.ibm.com>
+ * Copyright 2014 IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) "hv-24x7: " fmt
+
+#include <linux/perf_event.h>
+#include <linux/module.h>
+#include <asm/firmware.h>
+#include <asm/hvcall.h>
+#include <asm/hv_24x7.h>
+#include <asm/hv_gpci.h>
+#include <asm/io.h>
+
+/* See arch/powerpc/include/asm/24x7.h for details on the hcall interface */
+
+/* TODO: Merging events:
+ * - Think of the hcall as an interface to a 4d array of counters:
+ * - x = domains
+ * - y = indexes in the domain (core, chip, vcpu, node, etc)
+ * - z = offset into the counter space
+ * - w = lpars (guest vms, "logical partitions")
+ * - A single request is: x,y,y_last,z,z_last,w,w_last
+ * - this means we can retrieve a rectangle of counters in y,z for a single
x.
+ *
+ * - Things to consider (ignoring w):
+ * - input cost_per_request = 16
+ * - output cost_per_result(ys,zs) = 8 + 8 * ys + ys * zs
+ * - limited number of requests per hcall (must fit into 4K bytes)
+ * - 4k = 16 [buffer header] - 16 [request size] * request_count
+ * - 255 requests per hcall
+ * - sometimes it will be more efficient to read extra data and discard
+ */
+
+PMU_RANGE_ATTR(domain, config, 0, 3); /* u3 0-6, one of HV_24X7_PERF_DOMAIN */
+PMU_RANGE_ATTR(starting_index, config, 16, 31); /* u16 */
+PMU_RANGE_ATTR(offset, config, 32, 63); /* u32, see "data_offset" */
+PMU_RANGE_ATTR(lpar, config1, 0, 15); /* u16 */
+
+PMU_RANGE_RESV(reserved1, config, 4, 15);
+PMU_RANGE_RESV(reserved2, config1, 16, 63);
+PMU_RANGE_RESV(reserved3, config2, 0, 63);
+
+static struct attribute *format_attr[] = {
+ &format_attr_domain.attr,
+ &format_attr_offset.attr,
+ &format_attr_starting_index.attr,
+ &format_attr_lpar.attr,
+ NULL,
+};
+
+static struct attribute_group format_group = {
+ .name = "format",
+ .attrs = format_attr,
+};
+
+static const struct attribute_group *attr_groups[] = {
+ &format_group,
+ NULL,
+};
+
+struct hv_perf_caps {
+ u16 version;
+ u16 other_allowed:1,
+ ga:1,
+ expanded:1,
+ lab:1,
+ unused:12;
+};
+
+static unsigned long hv_perf_caps_get(struct hv_perf_caps *caps)
+{
+ unsigned long r;
+ struct p {
+ struct hv_get_perf_counter_info_params params;
+ struct cv_system_performance_capabilities caps;
+ } __packed __aligned(sizeof(uint64_t));
+
+ struct p arg = {
+ .params = {
+ .counter_request = cpu_to_be32(
+ CIR_system_performance_capabilities),
+ .starting_index = cpu_to_be32(-1),
+ .counter_info_version_in = 0,
+ }
+ };
+
+ r = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO,
+ virt_to_phys(&arg), sizeof(arg));
+ caps->version = arg.params.counter_info_version_out;
+ caps->other_allowed = arg.caps.perf_collect_privlidged;
+ caps->ga = (arg.caps.capability_mask & CV_CM_GA) >> CV_CM_GA;
+ caps->expanded = (arg.caps.capability_mask & CV_CM_EXPANDED)
+ >> CV_CM_EXPANDED;
+ caps->lab = (arg.caps.capability_mask & CV_CM_LAB) >> CV_CM_LAB;
+
+ return r;
+}
+
+static bool is_physical_domain(int domain)
+{
+ return domain == HV_24X7_PERF_DOMAIN_PHYSICAL_CHIP ||
+ domain == HV_24X7_PERF_DOMAIN_PHYSICAL_CORE;
+}
+
+static unsigned long single_24x7_request(u8 domain, u32 offset, u16 ix,
+ u16 lpar, u64 *res)
+{
+ unsigned long ret;
+ struct reqb {
+ struct hv_24x7_request_buffer buf;
+ struct hv_24x7_request req;
+ } request_buffer = {
+ .buf = {
+ .interface_version = HV_24X7_IF_VERSION_CURRENT,
+ .num_requests = 1,
+ },
+ .req = {
+ .performance_domain = domain,
+ .data_size = cpu_to_be16(8),
+ .data_offset = cpu_to_be32(offset),
+ .starting_lpar_ix = cpu_to_be16(lpar),
+ .max_num_lpars = cpu_to_be16(1),
+ .starting_ix = cpu_to_be16(ix),
+ .max_ix = cpu_to_be16(1),
+ }
+ };
+
+ struct resb {
+ struct hv_24x7_data_result_buffer buf;
+ struct hv_24x7_result res;
+ struct hv_24x7_result_element elem;
+ __be64 result;
+ } result_buffer = {};
+
+ ret = plpar_hcall_norets(H_GET_24X7_DATA,
+ virt_to_phys(&request_buffer), sizeof(request_buffer),
+ virt_to_phys(&result_buffer), sizeof(result_buffer));
+
+ if (ret) {
+ /*
+ * this failure is unexpected since we check if the exact same
+ * hcall works in event_init
+ */
+ pr_err_ratelimited("hcall failed: %d %#x %#x %d => 0x%lx (%ld)
detail=0x%x failing ix=%x\n",
+ domain, offset, ix, lpar,
+ ret, ret,
+ result_buffer.buf.detailed_rc,
+ result_buffer.buf.failing_request_ix);
+ return ret;
+ }
+
+ *res = be64_to_cpu(result_buffer.result);
+ return ret;
+}
+
+static int h_24x7_event_init(struct perf_event *event)
+{
+ struct hv_perf_caps caps;
+ unsigned domain;
+ u64 ct;
+
+ /* Not our event */
+ if (event->attr.type != event->pmu->type)
+ return -ENOENT;
+
+ /* Unused areas must be 0 */
+ if (event_get_reserved1(event) ||
+ event_get_reserved2(event) ||
+ event_get_reserved3(event)) {
+ pr_devel("reserved set when forbidden 0x%llx(0x%llx)
0x%llx(0x%llx) 0x%llx(0x%llx)\n",
+ event->attr.config,
+ event_get_reserved1(event),
+ event->attr.config1,
+ event_get_reserved2(event),
+ event->attr.config2,
+ event_get_reserved3(event));
+ return -EINVAL;
+ }
+
+ /* unsupported modes and filters */
+ if (event->attr.exclude_user ||
+ event->attr.exclude_kernel ||
+ event->attr.exclude_hv ||
+ event->attr.exclude_idle ||
+ event->attr.exclude_host ||
+ event->attr.exclude_guest ||
+ is_sampling_event(event)) /* no sampling */
+ return -EINVAL;
+
+ /* no branch sampling */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
+ /* offset must be 8 byte aligned */
+ if (event_get_offset(event) % 8) {
+ pr_devel("bad alignment\n");
+ return -EINVAL;
+ }
+
+ /* Domains above 6 are invalid */
+ domain = event_get_domain(event);
+ if (domain > 6) {
+ pr_devel("invalid domain\n");
+ return -EINVAL;
+ }
+
+ if (hv_perf_caps_get(&caps)) {
+ pr_devel("could not get capabilities\n");
+ return -EIO;
+ }
+
+ /* PHYSICAL domains & other lpars require extra capabilities */
+ if (!caps.other_allowed && (is_physical_domain(domain) ||
+ (event_get_lpar(event) != event_get_lpar_max()))) {
+ pr_devel("hv permisions disallow\n");
+ return -EPERM;
+ }
+
+ /* see if the event complains */
+ if (single_24x7_request(event_get_domain(event),
+ event_get_offset(event),
+ event_get_starting_index(event),
+ event_get_lpar(event),
+ &ct)) {
+ pr_devel("test hcall failed\n");
+ return -EIO;
+ }
+
+ /*
+ * Some of the events are per-cpu, some per-core, some per-chip, some
+ * are global, and some access data from other virtual machines on the
+ * same physical machine. We can't map the cpu value without a lot of
+ * work. Instead, we pick an arbitrary cpu for all events on this pmu.
+ */
+ event->cpu = 0;
+
+ perf_swevent_init_hrtimer(event);
+ return 0;
+}
+
+static u64 h_24x7_get_value(struct perf_event *event)
+{
+ unsigned long ret;
+ u64 ct;
+ ret = single_24x7_request(event_get_domain(event),
+ event_get_offset(event),
+ event_get_starting_index(event),
+ event_get_lpar(event),
+ &ct);
+ if (ret)
+ /* We checked this in event init, shouldn't fail here... */
+ return 0;
+
+ return ct;
+}
+
+static void h_24x7_event_update(struct perf_event *event)
+{
+ s64 prev;
+ u64 now;
+ now = h_24x7_get_value(event);
+ prev = local64_xchg(&event->hw.prev_count, now);
+ local64_add(now - prev, &event->count);
+}
+
+static void h_24x7_event_start(struct perf_event *event, int flags)
+{
+ if (flags & PERF_EF_RELOAD)
+ local64_set(&event->hw.prev_count, h_24x7_get_value(event));
+ perf_swevent_start_hrtimer(event);
+}
+
+static void h_24x7_event_stop(struct perf_event *event, int flags)
+{
+ perf_swevent_cancel_hrtimer(event);
+ h_24x7_event_update(event);
+}
+
+static int h_24x7_event_add(struct perf_event *event, int flags)
+{
+ if (flags & PERF_EF_START)
+ h_24x7_event_start(event, flags);
+
+ return 0;
+}
+
+static void h_24x7_event_del(struct perf_event *event, int flags)
+{
+ h_24x7_event_stop(event, flags);
+}
+
+static void h_24x7_event_read(struct perf_event *event)
+{
+ h_24x7_event_update(event);
+}
+
+struct pmu h_24x7_pmu = {
+ .task_ctx_nr = perf_invalid_context,
+
+ .name = "hv_24x7",
+ .attr_groups = attr_groups,
+ .event_init = h_24x7_event_init,
+ .add = h_24x7_event_add,
+ .del = h_24x7_event_del,
+ .start = h_24x7_event_start,
+ .stop = h_24x7_event_stop,
+ .read = h_24x7_event_read,
+
+ .event_idx = perf_swevent_event_idx,
+};
+
+static int hv_24x7_init(void)
+{
+ int r;
+ unsigned long hret;
+ struct hv_perf_caps caps;
+
+ if (!firmware_has_feature(FW_FEATURE_LPAR)) {
+ pr_info("not an lpar, disabled\n");
+ return -ENODEV;
+ }
+
+ hret = hv_perf_caps_get(&caps);
+ if (hret) {
+ pr_info("could not obtain capabilities, error 0x%80lx,
disabling\n",
+ hret);
+ return -ENODEV;
+ }
+
+ pr_info("gpci interface versions: hv:0x%x, kernel:0x%x\n",
+ caps.version, COUNTER_INFO_VERSION_CURRENT);
+
+ pr_info("gpci interface capabilities: other:%d ga:%d expanded:%d
lab:%d\n",
+ caps.other_allowed, caps.ga,
+ caps.expanded,
+ caps.lab);
+
+ r = perf_pmu_register(&h_24x7_pmu, h_24x7_pmu.name, -1);
+ if (r)
+ return r;
+
+ return 0;
+}
+
+module_init(hv_24x7_init);
--
1.8.5.2
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