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-rw-r--r--arch/powerpc/perf/hv-24x7.c1775
1 files changed, 1775 insertions, 0 deletions
diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c
new file mode 100644
index 000000000..7dda59923
--- /dev/null
+++ b/arch/powerpc/perf/hv-24x7.c
@@ -0,0 +1,1775 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Hypervisor supplied "24x7" performance counter support
+ *
+ * Author: Cody P Schafer <cody@linux.vnet.ibm.com>
+ * Copyright 2014 IBM Corporation.
+ */
+
+#define pr_fmt(fmt) "hv-24x7: " fmt
+
+#include <linux/perf_event.h>
+#include <linux/rbtree.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include <asm/cputhreads.h>
+#include <asm/firmware.h>
+#include <asm/hvcall.h>
+#include <asm/io.h>
+#include <linux/byteorder/generic.h>
+
+#include <asm/rtas.h>
+#include "hv-24x7.h"
+#include "hv-24x7-catalog.h"
+#include "hv-common.h"
+
+/* Version of the 24x7 hypervisor API that we should use in this machine. */
+static int interface_version;
+
+/* Whether we have to aggregate result data for some domains. */
+static bool aggregate_result_elements;
+
+static cpumask_t hv_24x7_cpumask;
+
+static bool domain_is_valid(unsigned int domain)
+{
+ switch (domain) {
+#define DOMAIN(n, v, x, c) \
+ case HV_PERF_DOMAIN_##n: \
+ /* fall through */
+#include "hv-24x7-domains.h"
+#undef DOMAIN
+ return true;
+ default:
+ return false;
+ }
+}
+
+static bool is_physical_domain(unsigned int domain)
+{
+ switch (domain) {
+#define DOMAIN(n, v, x, c) \
+ case HV_PERF_DOMAIN_##n: \
+ return c;
+#include "hv-24x7-domains.h"
+#undef DOMAIN
+ default:
+ return false;
+ }
+}
+
+/*
+ * The Processor Module Information system parameter allows transferring
+ * of certain processor module information from the platform to the OS.
+ * Refer PAPR+ document to get parameter token value as '43'.
+ */
+
+#define PROCESSOR_MODULE_INFO 43
+
+static u32 phys_sockets; /* Physical sockets */
+static u32 phys_chipspersocket; /* Physical chips per socket*/
+static u32 phys_coresperchip; /* Physical cores per chip */
+
+/*
+ * read_24x7_sys_info()
+ * Retrieve the number of sockets and chips per socket and cores per
+ * chip details through the get-system-parameter rtas call.
+ */
+void read_24x7_sys_info(void)
+{
+ int call_status, len, ntypes;
+
+ spin_lock(&rtas_data_buf_lock);
+
+ /*
+ * Making system parameter: chips and sockets and cores per chip
+ * default to 1.
+ */
+ phys_sockets = 1;
+ phys_chipspersocket = 1;
+ phys_coresperchip = 1;
+
+ call_status = rtas_call(rtas_token("ibm,get-system-parameter"), 3, 1,
+ NULL,
+ PROCESSOR_MODULE_INFO,
+ __pa(rtas_data_buf),
+ RTAS_DATA_BUF_SIZE);
+
+ if (call_status != 0) {
+ pr_err("Error calling get-system-parameter %d\n",
+ call_status);
+ } else {
+ len = be16_to_cpup((__be16 *)&rtas_data_buf[0]);
+ if (len < 8)
+ goto out;
+
+ ntypes = be16_to_cpup((__be16 *)&rtas_data_buf[2]);
+
+ if (!ntypes)
+ goto out;
+
+ phys_sockets = be16_to_cpup((__be16 *)&rtas_data_buf[4]);
+ phys_chipspersocket = be16_to_cpup((__be16 *)&rtas_data_buf[6]);
+ phys_coresperchip = be16_to_cpup((__be16 *)&rtas_data_buf[8]);
+ }
+
+out:
+ spin_unlock(&rtas_data_buf_lock);
+}
+
+/* Domains for which more than one result element are returned for each event. */
+static bool domain_needs_aggregation(unsigned int domain)
+{
+ return aggregate_result_elements &&
+ (domain == HV_PERF_DOMAIN_PHYS_CORE ||
+ (domain >= HV_PERF_DOMAIN_VCPU_HOME_CORE &&
+ domain <= HV_PERF_DOMAIN_VCPU_REMOTE_NODE));
+}
+
+static const char *domain_name(unsigned int domain)
+{
+ if (!domain_is_valid(domain))
+ return NULL;
+
+ switch (domain) {
+ case HV_PERF_DOMAIN_PHYS_CHIP: return "Physical Chip";
+ case HV_PERF_DOMAIN_PHYS_CORE: return "Physical Core";
+ case HV_PERF_DOMAIN_VCPU_HOME_CORE: return "VCPU Home Core";
+ case HV_PERF_DOMAIN_VCPU_HOME_CHIP: return "VCPU Home Chip";
+ case HV_PERF_DOMAIN_VCPU_HOME_NODE: return "VCPU Home Node";
+ case HV_PERF_DOMAIN_VCPU_REMOTE_NODE: return "VCPU Remote Node";
+ }
+
+ WARN_ON_ONCE(domain);
+ return NULL;
+}
+
+static bool catalog_entry_domain_is_valid(unsigned int domain)
+{
+ /* POWER8 doesn't support virtual domains. */
+ if (interface_version == 1)
+ return is_physical_domain(domain);
+ else
+ return domain_is_valid(domain);
+}
+
+/*
+ * 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
+ */
+
+/*
+ * Example usage:
+ * perf stat -e 'hv_24x7/domain=2,offset=8,vcpu=0,lpar=0xffffffff/'
+ */
+
+/* u3 0-6, one of HV_24X7_PERF_DOMAIN */
+EVENT_DEFINE_RANGE_FORMAT(domain, config, 0, 3);
+/* u16 */
+EVENT_DEFINE_RANGE_FORMAT(core, config, 16, 31);
+EVENT_DEFINE_RANGE_FORMAT(chip, config, 16, 31);
+EVENT_DEFINE_RANGE_FORMAT(vcpu, config, 16, 31);
+/* u32, see "data_offset" */
+EVENT_DEFINE_RANGE_FORMAT(offset, config, 32, 63);
+/* u16 */
+EVENT_DEFINE_RANGE_FORMAT(lpar, config1, 0, 15);
+
+EVENT_DEFINE_RANGE(reserved1, config, 4, 15);
+EVENT_DEFINE_RANGE(reserved2, config1, 16, 63);
+EVENT_DEFINE_RANGE(reserved3, config2, 0, 63);
+
+static struct attribute *format_attrs[] = {
+ &format_attr_domain.attr,
+ &format_attr_offset.attr,
+ &format_attr_core.attr,
+ &format_attr_chip.attr,
+ &format_attr_vcpu.attr,
+ &format_attr_lpar.attr,
+ NULL,
+};
+
+static const struct attribute_group format_group = {
+ .name = "format",
+ .attrs = format_attrs,
+};
+
+static struct attribute_group event_group = {
+ .name = "events",
+ /* .attrs is set in init */
+};
+
+static struct attribute_group event_desc_group = {
+ .name = "event_descs",
+ /* .attrs is set in init */
+};
+
+static struct attribute_group event_long_desc_group = {
+ .name = "event_long_descs",
+ /* .attrs is set in init */
+};
+
+static struct kmem_cache *hv_page_cache;
+
+static DEFINE_PER_CPU(int, hv_24x7_txn_flags);
+static DEFINE_PER_CPU(int, hv_24x7_txn_err);
+
+struct hv_24x7_hw {
+ struct perf_event *events[255];
+};
+
+static DEFINE_PER_CPU(struct hv_24x7_hw, hv_24x7_hw);
+
+/*
+ * request_buffer and result_buffer are not required to be 4k aligned,
+ * but are not allowed to cross any 4k boundary. Aligning them to 4k is
+ * the simplest way to ensure that.
+ */
+#define H24x7_DATA_BUFFER_SIZE 4096
+static DEFINE_PER_CPU(char, hv_24x7_reqb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096);
+static DEFINE_PER_CPU(char, hv_24x7_resb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096);
+
+static unsigned int max_num_requests(int interface_version)
+{
+ return (H24x7_DATA_BUFFER_SIZE - sizeof(struct hv_24x7_request_buffer))
+ / H24x7_REQUEST_SIZE(interface_version);
+}
+
+static char *event_name(struct hv_24x7_event_data *ev, int *len)
+{
+ *len = be16_to_cpu(ev->event_name_len) - 2;
+ return (char *)ev->remainder;
+}
+
+static char *event_desc(struct hv_24x7_event_data *ev, int *len)
+{
+ unsigned int nl = be16_to_cpu(ev->event_name_len);
+ __be16 *desc_len = (__be16 *)(ev->remainder + nl - 2);
+
+ *len = be16_to_cpu(*desc_len) - 2;
+ return (char *)ev->remainder + nl;
+}
+
+static char *event_long_desc(struct hv_24x7_event_data *ev, int *len)
+{
+ unsigned int nl = be16_to_cpu(ev->event_name_len);
+ __be16 *desc_len_ = (__be16 *)(ev->remainder + nl - 2);
+ unsigned int desc_len = be16_to_cpu(*desc_len_);
+ __be16 *long_desc_len = (__be16 *)(ev->remainder + nl + desc_len - 2);
+
+ *len = be16_to_cpu(*long_desc_len) - 2;
+ return (char *)ev->remainder + nl + desc_len;
+}
+
+static bool event_fixed_portion_is_within(struct hv_24x7_event_data *ev,
+ void *end)
+{
+ void *start = ev;
+
+ return (start + offsetof(struct hv_24x7_event_data, remainder)) < end;
+}
+
+/*
+ * Things we don't check:
+ * - padding for desc, name, and long/detailed desc is required to be '\0'
+ * bytes.
+ *
+ * Return NULL if we pass end,
+ * Otherwise return the address of the byte just following the event.
+ */
+static void *event_end(struct hv_24x7_event_data *ev, void *end)
+{
+ void *start = ev;
+ __be16 *dl_, *ldl_;
+ unsigned int dl, ldl;
+ unsigned int nl = be16_to_cpu(ev->event_name_len);
+
+ if (nl < 2) {
+ pr_debug("%s: name length too short: %d", __func__, nl);
+ return NULL;
+ }
+
+ if (start + nl > end) {
+ pr_debug("%s: start=%p + nl=%u > end=%p",
+ __func__, start, nl, end);
+ return NULL;
+ }
+
+ dl_ = (__be16 *)(ev->remainder + nl - 2);
+ if (!IS_ALIGNED((uintptr_t)dl_, 2))
+ pr_warn("desc len not aligned %p", dl_);
+ dl = be16_to_cpu(*dl_);
+ if (dl < 2) {
+ pr_debug("%s: desc len too short: %d", __func__, dl);
+ return NULL;
+ }
+
+ if (start + nl + dl > end) {
+ pr_debug("%s: (start=%p + nl=%u + dl=%u)=%p > end=%p",
+ __func__, start, nl, dl, start + nl + dl, end);
+ return NULL;
+ }
+
+ ldl_ = (__be16 *)(ev->remainder + nl + dl - 2);
+ if (!IS_ALIGNED((uintptr_t)ldl_, 2))
+ pr_warn("long desc len not aligned %p", ldl_);
+ ldl = be16_to_cpu(*ldl_);
+ if (ldl < 2) {
+ pr_debug("%s: long desc len too short (ldl=%u)",
+ __func__, ldl);
+ return NULL;
+ }
+
+ if (start + nl + dl + ldl > end) {
+ pr_debug("%s: start=%p + nl=%u + dl=%u + ldl=%u > end=%p",
+ __func__, start, nl, dl, ldl, end);
+ return NULL;
+ }
+
+ return start + nl + dl + ldl;
+}
+
+static long h_get_24x7_catalog_page_(unsigned long phys_4096,
+ unsigned long version, unsigned long index)
+{
+ pr_devel("h_get_24x7_catalog_page(0x%lx, %lu, %lu)",
+ phys_4096, version, index);
+
+ WARN_ON(!IS_ALIGNED(phys_4096, 4096));
+
+ return plpar_hcall_norets(H_GET_24X7_CATALOG_PAGE,
+ phys_4096, version, index);
+}
+
+static long h_get_24x7_catalog_page(char page[], u64 version, u32 index)
+{
+ return h_get_24x7_catalog_page_(virt_to_phys(page),
+ version, index);
+}
+
+/*
+ * Each event we find in the catalog, will have a sysfs entry. Format the
+ * data for this sysfs entry based on the event's domain.
+ *
+ * Events belonging to the Chip domain can only be monitored in that domain.
+ * i.e the domain for these events is a fixed/knwon value.
+ *
+ * Events belonging to the Core domain can be monitored either in the physical
+ * core or in one of the virtual CPU domains. So the domain value for these
+ * events must be specified by the user (i.e is a required parameter). Format
+ * the Core events with 'domain=?' so the perf-tool can error check required
+ * parameters.
+ *
+ * NOTE: For the Core domain events, rather than making domain a required
+ * parameter we could default it to PHYS_CORE and allowe users to
+ * override the domain to one of the VCPU domains.
+ *
+ * However, this can make the interface a little inconsistent.
+ *
+ * If we set domain=2 (PHYS_CHIP) and allow user to override this field
+ * the user may be tempted to also modify the "offset=x" field in which
+ * can lead to confusing usage. Consider the HPM_PCYC (offset=0x18) and
+ * HPM_INST (offset=0x20) events. With:
+ *
+ * perf stat -e hv_24x7/HPM_PCYC,offset=0x20/
+ *
+ * we end up monitoring HPM_INST, while the command line has HPM_PCYC.
+ *
+ * By not assigning a default value to the domain for the Core events,
+ * we can have simple guidelines:
+ *
+ * - Specifying values for parameters with "=?" is required.
+ *
+ * - Specifying (i.e overriding) values for other parameters
+ * is undefined.
+ */
+static char *event_fmt(struct hv_24x7_event_data *event, unsigned int domain)
+{
+ const char *sindex;
+ const char *lpar;
+ const char *domain_str;
+ char buf[8];
+
+ switch (domain) {
+ case HV_PERF_DOMAIN_PHYS_CHIP:
+ snprintf(buf, sizeof(buf), "%d", domain);
+ domain_str = buf;
+ lpar = "0x0";
+ sindex = "chip";
+ break;
+ case HV_PERF_DOMAIN_PHYS_CORE:
+ domain_str = "?";
+ lpar = "0x0";
+ sindex = "core";
+ break;
+ default:
+ domain_str = "?";
+ lpar = "?";
+ sindex = "vcpu";
+ }
+
+ return kasprintf(GFP_KERNEL,
+ "domain=%s,offset=0x%x,%s=?,lpar=%s",
+ domain_str,
+ be16_to_cpu(event->event_counter_offs) +
+ be16_to_cpu(event->event_group_record_offs),
+ sindex,
+ lpar);
+}
+
+/* Avoid trusting fw to NUL terminate strings */
+static char *memdup_to_str(char *maybe_str, int max_len, gfp_t gfp)
+{
+ return kasprintf(gfp, "%.*s", max_len, maybe_str);
+}
+
+static ssize_t device_show_string(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct dev_ext_attribute *d;
+
+ d = container_of(attr, struct dev_ext_attribute, attr);
+
+ return sprintf(buf, "%s\n", (char *)d->var);
+}
+
+static ssize_t cpumask_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return cpumap_print_to_pagebuf(true, buf, &hv_24x7_cpumask);
+}
+
+static ssize_t sockets_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n", phys_sockets);
+}
+
+static ssize_t chipspersocket_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n", phys_chipspersocket);
+}
+
+static ssize_t coresperchip_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n", phys_coresperchip);
+}
+
+static struct attribute *device_str_attr_create_(char *name, char *str)
+{
+ struct dev_ext_attribute *attr = kzalloc(sizeof(*attr), GFP_KERNEL);
+
+ if (!attr)
+ return NULL;
+
+ sysfs_attr_init(&attr->attr.attr);
+
+ attr->var = str;
+ attr->attr.attr.name = name;
+ attr->attr.attr.mode = 0444;
+ attr->attr.show = device_show_string;
+
+ return &attr->attr.attr;
+}
+
+/*
+ * Allocate and initialize strings representing event attributes.
+ *
+ * NOTE: The strings allocated here are never destroyed and continue to
+ * exist till shutdown. This is to allow us to create as many events
+ * from the catalog as possible, even if we encounter errors with some.
+ * In case of changes to error paths in future, these may need to be
+ * freed by the caller.
+ */
+static struct attribute *device_str_attr_create(char *name, int name_max,
+ int name_nonce,
+ char *str, size_t str_max)
+{
+ char *n;
+ char *s = memdup_to_str(str, str_max, GFP_KERNEL);
+ struct attribute *a;
+
+ if (!s)
+ return NULL;
+
+ if (!name_nonce)
+ n = kasprintf(GFP_KERNEL, "%.*s", name_max, name);
+ else
+ n = kasprintf(GFP_KERNEL, "%.*s__%d", name_max, name,
+ name_nonce);
+ if (!n)
+ goto out_s;
+
+ a = device_str_attr_create_(n, s);
+ if (!a)
+ goto out_n;
+
+ return a;
+out_n:
+ kfree(n);
+out_s:
+ kfree(s);
+ return NULL;
+}
+
+static struct attribute *event_to_attr(unsigned int ix,
+ struct hv_24x7_event_data *event,
+ unsigned int domain,
+ int nonce)
+{
+ int event_name_len;
+ char *ev_name, *a_ev_name, *val;
+ struct attribute *attr;
+
+ if (!domain_is_valid(domain)) {
+ pr_warn("catalog event %u has invalid domain %u\n",
+ ix, domain);
+ return NULL;
+ }
+
+ val = event_fmt(event, domain);
+ if (!val)
+ return NULL;
+
+ ev_name = event_name(event, &event_name_len);
+ if (!nonce)
+ a_ev_name = kasprintf(GFP_KERNEL, "%.*s",
+ (int)event_name_len, ev_name);
+ else
+ a_ev_name = kasprintf(GFP_KERNEL, "%.*s__%d",
+ (int)event_name_len, ev_name, nonce);
+
+ if (!a_ev_name)
+ goto out_val;
+
+ attr = device_str_attr_create_(a_ev_name, val);
+ if (!attr)
+ goto out_name;
+
+ return attr;
+out_name:
+ kfree(a_ev_name);
+out_val:
+ kfree(val);
+ return NULL;
+}
+
+static struct attribute *event_to_desc_attr(struct hv_24x7_event_data *event,
+ int nonce)
+{
+ int nl, dl;
+ char *name = event_name(event, &nl);
+ char *desc = event_desc(event, &dl);
+
+ /* If there isn't a description, don't create the sysfs file */
+ if (!dl)
+ return NULL;
+
+ return device_str_attr_create(name, nl, nonce, desc, dl);
+}
+
+static struct attribute *
+event_to_long_desc_attr(struct hv_24x7_event_data *event, int nonce)
+{
+ int nl, dl;
+ char *name = event_name(event, &nl);
+ char *desc = event_long_desc(event, &dl);
+
+ /* If there isn't a description, don't create the sysfs file */
+ if (!dl)
+ return NULL;
+
+ return device_str_attr_create(name, nl, nonce, desc, dl);
+}
+
+static int event_data_to_attrs(unsigned int ix, struct attribute **attrs,
+ struct hv_24x7_event_data *event, int nonce)
+{
+ *attrs = event_to_attr(ix, event, event->domain, nonce);
+ if (!*attrs)
+ return -1;
+
+ return 0;
+}
+
+/* */
+struct event_uniq {
+ struct rb_node node;
+ const char *name;
+ int nl;
+ unsigned int ct;
+ unsigned int domain;
+};
+
+static int memord(const void *d1, size_t s1, const void *d2, size_t s2)
+{
+ if (s1 < s2)
+ return 1;
+ if (s1 > s2)
+ return -1;
+
+ return memcmp(d1, d2, s1);
+}
+
+static int ev_uniq_ord(const void *v1, size_t s1, unsigned int d1,
+ const void *v2, size_t s2, unsigned int d2)
+{
+ int r = memord(v1, s1, v2, s2);
+
+ if (r)
+ return r;
+ if (d1 > d2)
+ return 1;
+ if (d2 > d1)
+ return -1;
+ return 0;
+}
+
+static int event_uniq_add(struct rb_root *root, const char *name, int nl,
+ unsigned int domain)
+{
+ struct rb_node **new = &(root->rb_node), *parent = NULL;
+ struct event_uniq *data;
+
+ /* Figure out where to put new node */
+ while (*new) {
+ struct event_uniq *it;
+ int result;
+
+ it = rb_entry(*new, struct event_uniq, node);
+ result = ev_uniq_ord(name, nl, domain, it->name, it->nl,
+ it->domain);
+
+ parent = *new;
+ if (result < 0)
+ new = &((*new)->rb_left);
+ else if (result > 0)
+ new = &((*new)->rb_right);
+ else {
+ it->ct++;
+ pr_info("found a duplicate event %.*s, ct=%u\n", nl,
+ name, it->ct);
+ return it->ct;
+ }
+ }
+
+ data = kmalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ *data = (struct event_uniq) {
+ .name = name,
+ .nl = nl,
+ .ct = 0,
+ .domain = domain,
+ };
+
+ /* Add new node and rebalance tree. */
+ rb_link_node(&data->node, parent, new);
+ rb_insert_color(&data->node, root);
+
+ /* data->ct */
+ return 0;
+}
+
+static void event_uniq_destroy(struct rb_root *root)
+{
+ /*
+ * the strings we point to are in the giant block of memory filled by
+ * the catalog, and are freed separately.
+ */
+ struct event_uniq *pos, *n;
+
+ rbtree_postorder_for_each_entry_safe(pos, n, root, node)
+ kfree(pos);
+}
+
+
+/*
+ * ensure the event structure's sizes are self consistent and don't cause us to
+ * read outside of the event
+ *
+ * On success, return the event length in bytes.
+ * Otherwise, return -1 (and print as appropriate).
+ */
+static ssize_t catalog_event_len_validate(struct hv_24x7_event_data *event,
+ size_t event_idx,
+ size_t event_data_bytes,
+ size_t event_entry_count,
+ size_t offset, void *end)
+{
+ ssize_t ev_len;
+ void *ev_end, *calc_ev_end;
+
+ if (offset >= event_data_bytes)
+ return -1;
+
+ if (event_idx >= event_entry_count) {
+ pr_devel("catalog event data has %zu bytes of padding after last event\n",
+ event_data_bytes - offset);
+ return -1;
+ }
+
+ if (!event_fixed_portion_is_within(event, end)) {
+ pr_warn("event %zu fixed portion is not within range\n",
+ event_idx);
+ return -1;
+ }
+
+ ev_len = be16_to_cpu(event->length);
+
+ if (ev_len % 16)
+ pr_info("event %zu has length %zu not divisible by 16: event=%pK\n",
+ event_idx, ev_len, event);
+
+ ev_end = (__u8 *)event + ev_len;
+ if (ev_end > end) {
+ pr_warn("event %zu has .length=%zu, ends after buffer end: ev_end=%pK > end=%pK, offset=%zu\n",
+ event_idx, ev_len, ev_end, end,
+ offset);
+ return -1;
+ }
+
+ calc_ev_end = event_end(event, end);
+ if (!calc_ev_end) {
+ pr_warn("event %zu has a calculated length which exceeds buffer length %zu: event=%pK end=%pK, offset=%zu\n",
+ event_idx, event_data_bytes, event, end,
+ offset);
+ return -1;
+ }
+
+ if (calc_ev_end > ev_end) {
+ pr_warn("event %zu exceeds its own length: event=%pK, end=%pK, offset=%zu, calc_ev_end=%pK\n",
+ event_idx, event, ev_end, offset, calc_ev_end);
+ return -1;
+ }
+
+ return ev_len;
+}
+
+/*
+ * Return true incase of invalid or dummy events with names like RESERVED*
+ */
+static bool ignore_event(const char *name)
+{
+ return strncmp(name, "RESERVED", 8) == 0;
+}
+
+#define MAX_4K (SIZE_MAX / 4096)
+
+static int create_events_from_catalog(struct attribute ***events_,
+ struct attribute ***event_descs_,
+ struct attribute ***event_long_descs_)
+{
+ long hret;
+ size_t catalog_len, catalog_page_len, event_entry_count,
+ event_data_len, event_data_offs,
+ event_data_bytes, junk_events, event_idx, event_attr_ct, i,
+ attr_max, event_idx_last, desc_ct, long_desc_ct;
+ ssize_t ct, ev_len;
+ uint64_t catalog_version_num;
+ struct attribute **events, **event_descs, **event_long_descs;
+ struct hv_24x7_catalog_page_0 *page_0 =
+ kmem_cache_alloc(hv_page_cache, GFP_KERNEL);
+ void *page = page_0;
+ void *event_data, *end;
+ struct hv_24x7_event_data *event;
+ struct rb_root ev_uniq = RB_ROOT;
+ int ret = 0;
+
+ if (!page) {
+ ret = -ENOMEM;
+ goto e_out;
+ }
+
+ hret = h_get_24x7_catalog_page(page, 0, 0);
+ if (hret) {
+ ret = -EIO;
+ goto e_free;
+ }
+
+ catalog_version_num = be64_to_cpu(page_0->version);
+ catalog_page_len = be32_to_cpu(page_0->length);
+
+ if (MAX_4K < catalog_page_len) {
+ pr_err("invalid page count: %zu\n", catalog_page_len);
+ ret = -EIO;
+ goto e_free;
+ }
+
+ catalog_len = catalog_page_len * 4096;
+
+ event_entry_count = be16_to_cpu(page_0->event_entry_count);
+ event_data_offs = be16_to_cpu(page_0->event_data_offs);
+ event_data_len = be16_to_cpu(page_0->event_data_len);
+
+ pr_devel("cv %llu cl %zu eec %zu edo %zu edl %zu\n",
+ catalog_version_num, catalog_len,
+ event_entry_count, event_data_offs, event_data_len);
+
+ if ((MAX_4K < event_data_len)
+ || (MAX_4K < event_data_offs)
+ || (MAX_4K - event_data_offs < event_data_len)) {
+ pr_err("invalid event data offs %zu and/or len %zu\n",
+ event_data_offs, event_data_len);
+ ret = -EIO;
+ goto e_free;
+ }
+
+ if ((event_data_offs + event_data_len) > catalog_page_len) {
+ pr_err("event data %zu-%zu does not fit inside catalog 0-%zu\n",
+ event_data_offs,
+ event_data_offs + event_data_len,
+ catalog_page_len);
+ ret = -EIO;
+ goto e_free;
+ }
+
+ if (SIZE_MAX - 1 < event_entry_count) {
+ pr_err("event_entry_count %zu is invalid\n", event_entry_count);
+ ret = -EIO;
+ goto e_free;
+ }
+
+ event_data_bytes = event_data_len * 4096;
+
+ /*
+ * event data can span several pages, events can cross between these
+ * pages. Use vmalloc to make this easier.
+ */
+ event_data = vmalloc(event_data_bytes);
+ if (!event_data) {
+ pr_err("could not allocate event data\n");
+ ret = -ENOMEM;
+ goto e_free;
+ }
+
+ end = event_data + event_data_bytes;
+
+ /*
+ * using vmalloc_to_phys() like this only works if PAGE_SIZE is
+ * divisible by 4096
+ */
+ BUILD_BUG_ON(PAGE_SIZE % 4096);
+
+ for (i = 0; i < event_data_len; i++) {
+ hret = h_get_24x7_catalog_page_(
+ vmalloc_to_phys(event_data + i * 4096),
+ catalog_version_num,
+ i + event_data_offs);
+ if (hret) {
+ pr_err("Failed to get event data in page %zu: rc=%ld\n",
+ i + event_data_offs, hret);
+ ret = -EIO;
+ goto e_event_data;
+ }
+ }
+
+ /*
+ * scan the catalog to determine the number of attributes we need, and
+ * verify it at the same time.
+ */
+ for (junk_events = 0, event = event_data, event_idx = 0, attr_max = 0;
+ ;
+ event_idx++, event = (void *)event + ev_len) {
+ size_t offset = (void *)event - (void *)event_data;
+ char *name;
+ int nl;
+
+ ev_len = catalog_event_len_validate(event, event_idx,
+ event_data_bytes,
+ event_entry_count,
+ offset, end);
+ if (ev_len < 0)
+ break;
+
+ name = event_name(event, &nl);
+
+ if (ignore_event(name)) {
+ junk_events++;
+ continue;
+ }
+ if (event->event_group_record_len == 0) {
+ pr_devel("invalid event %zu (%.*s): group_record_len == 0, skipping\n",
+ event_idx, nl, name);
+ junk_events++;
+ continue;
+ }
+
+ if (!catalog_entry_domain_is_valid(event->domain)) {
+ pr_info("event %zu (%.*s) has invalid domain %d\n",
+ event_idx, nl, name, event->domain);
+ junk_events++;
+ continue;
+ }
+
+ attr_max++;
+ }
+
+ event_idx_last = event_idx;
+ if (event_idx_last != event_entry_count)
+ pr_warn("event buffer ended before listed # of events were parsed (got %zu, wanted %zu, junk %zu)\n",
+ event_idx_last, event_entry_count, junk_events);
+
+ events = kmalloc_array(attr_max + 1, sizeof(*events), GFP_KERNEL);
+ if (!events) {
+ ret = -ENOMEM;
+ goto e_event_data;
+ }
+
+ event_descs = kmalloc_array(event_idx + 1, sizeof(*event_descs),
+ GFP_KERNEL);
+ if (!event_descs) {
+ ret = -ENOMEM;
+ goto e_event_attrs;
+ }
+
+ event_long_descs = kmalloc_array(event_idx + 1,
+ sizeof(*event_long_descs), GFP_KERNEL);
+ if (!event_long_descs) {
+ ret = -ENOMEM;
+ goto e_event_descs;
+ }
+
+ /* Iterate over the catalog filling in the attribute vector */
+ for (junk_events = 0, event_attr_ct = 0, desc_ct = 0, long_desc_ct = 0,
+ event = event_data, event_idx = 0;
+ event_idx < event_idx_last;
+ event_idx++, ev_len = be16_to_cpu(event->length),
+ event = (void *)event + ev_len) {
+ char *name;
+ int nl;
+ int nonce;
+ /*
+ * these are the only "bad" events that are intermixed and that
+ * we can ignore without issue. make sure to skip them here
+ */
+ if (event->event_group_record_len == 0)
+ continue;
+ if (!catalog_entry_domain_is_valid(event->domain))
+ continue;
+
+ name = event_name(event, &nl);
+ if (ignore_event(name))
+ continue;
+
+ nonce = event_uniq_add(&ev_uniq, name, nl, event->domain);
+ ct = event_data_to_attrs(event_idx, events + event_attr_ct,
+ event, nonce);
+ if (ct < 0) {
+ pr_warn("event %zu (%.*s) creation failure, skipping\n",
+ event_idx, nl, name);
+ junk_events++;
+ } else {
+ event_attr_ct++;
+ event_descs[desc_ct] = event_to_desc_attr(event, nonce);
+ if (event_descs[desc_ct])
+ desc_ct++;
+ event_long_descs[long_desc_ct] =
+ event_to_long_desc_attr(event, nonce);
+ if (event_long_descs[long_desc_ct])
+ long_desc_ct++;
+ }
+ }
+
+ pr_info("read %zu catalog entries, created %zu event attrs (%zu failures), %zu descs\n",
+ event_idx, event_attr_ct, junk_events, desc_ct);
+
+ events[event_attr_ct] = NULL;
+ event_descs[desc_ct] = NULL;
+ event_long_descs[long_desc_ct] = NULL;
+
+ event_uniq_destroy(&ev_uniq);
+ vfree(event_data);
+ kmem_cache_free(hv_page_cache, page);
+
+ *events_ = events;
+ *event_descs_ = event_descs;
+ *event_long_descs_ = event_long_descs;
+ return 0;
+
+e_event_descs:
+ kfree(event_descs);
+e_event_attrs:
+ kfree(events);
+e_event_data:
+ vfree(event_data);
+e_free:
+ kmem_cache_free(hv_page_cache, page);
+e_out:
+ *events_ = NULL;
+ *event_descs_ = NULL;
+ *event_long_descs_ = NULL;
+ return ret;
+}
+
+static ssize_t catalog_read(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr, char *buf,
+ loff_t offset, size_t count)
+{
+ long hret;
+ ssize_t ret = 0;
+ size_t catalog_len = 0, catalog_page_len = 0;
+ loff_t page_offset = 0;
+ loff_t offset_in_page;
+ size_t copy_len;
+ uint64_t catalog_version_num = 0;
+ void *page = kmem_cache_alloc(hv_page_cache, GFP_USER);
+ struct hv_24x7_catalog_page_0 *page_0 = page;
+
+ if (!page)
+ return -ENOMEM;
+
+ hret = h_get_24x7_catalog_page(page, 0, 0);
+ if (hret) {
+ ret = -EIO;
+ goto e_free;
+ }
+
+ catalog_version_num = be64_to_cpu(page_0->version);
+ catalog_page_len = be32_to_cpu(page_0->length);
+ catalog_len = catalog_page_len * 4096;
+
+ page_offset = offset / 4096;
+ offset_in_page = offset % 4096;
+
+ if (page_offset >= catalog_page_len)
+ goto e_free;
+
+ if (page_offset != 0) {
+ hret = h_get_24x7_catalog_page(page, catalog_version_num,
+ page_offset);
+ if (hret) {
+ ret = -EIO;
+ goto e_free;
+ }
+ }
+
+ copy_len = 4096 - offset_in_page;
+ if (copy_len > count)
+ copy_len = count;
+
+ memcpy(buf, page+offset_in_page, copy_len);
+ ret = copy_len;
+
+e_free:
+ if (hret)
+ pr_err("h_get_24x7_catalog_page(ver=%lld, page=%lld) failed:"
+ " rc=%ld\n",
+ catalog_version_num, page_offset, hret);
+ kmem_cache_free(hv_page_cache, page);
+
+ pr_devel("catalog_read: offset=%lld(%lld) count=%zu "
+ "catalog_len=%zu(%zu) => %zd\n", offset, page_offset,
+ count, catalog_len, catalog_page_len, ret);
+
+ return ret;
+}
+
+static ssize_t domains_show(struct device *dev, struct device_attribute *attr,
+ char *page)
+{
+ int d, n, count = 0;
+ const char *str;
+
+ for (d = 0; d < HV_PERF_DOMAIN_MAX; d++) {
+ str = domain_name(d);
+ if (!str)
+ continue;
+
+ n = sprintf(page, "%d: %s\n", d, str);
+ if (n < 0)
+ break;
+
+ count += n;
+ page += n;
+ }
+ return count;
+}
+
+#define PAGE_0_ATTR(_name, _fmt, _expr) \
+static ssize_t _name##_show(struct device *dev, \
+ struct device_attribute *dev_attr, \
+ char *buf) \
+{ \
+ long hret; \
+ ssize_t ret = 0; \
+ void *page = kmem_cache_alloc(hv_page_cache, GFP_USER); \
+ struct hv_24x7_catalog_page_0 *page_0 = page; \
+ if (!page) \
+ return -ENOMEM; \
+ hret = h_get_24x7_catalog_page(page, 0, 0); \
+ if (hret) { \
+ ret = -EIO; \
+ goto e_free; \
+ } \
+ ret = sprintf(buf, _fmt, _expr); \
+e_free: \
+ kmem_cache_free(hv_page_cache, page); \
+ return ret; \
+} \
+static DEVICE_ATTR_RO(_name)
+
+PAGE_0_ATTR(catalog_version, "%lld\n",
+ (unsigned long long)be64_to_cpu(page_0->version));
+PAGE_0_ATTR(catalog_len, "%lld\n",
+ (unsigned long long)be32_to_cpu(page_0->length) * 4096);
+static BIN_ATTR_RO(catalog, 0/* real length varies */);
+static DEVICE_ATTR_RO(domains);
+static DEVICE_ATTR_RO(sockets);
+static DEVICE_ATTR_RO(chipspersocket);
+static DEVICE_ATTR_RO(coresperchip);
+static DEVICE_ATTR_RO(cpumask);
+
+static struct bin_attribute *if_bin_attrs[] = {
+ &bin_attr_catalog,
+ NULL,
+};
+
+static struct attribute *cpumask_attrs[] = {
+ &dev_attr_cpumask.attr,
+ NULL,
+};
+
+static const struct attribute_group cpumask_attr_group = {
+ .attrs = cpumask_attrs,
+};
+
+static struct attribute *if_attrs[] = {
+ &dev_attr_catalog_len.attr,
+ &dev_attr_catalog_version.attr,
+ &dev_attr_domains.attr,
+ &dev_attr_sockets.attr,
+ &dev_attr_chipspersocket.attr,
+ &dev_attr_coresperchip.attr,
+ NULL,
+};
+
+static const struct attribute_group if_group = {
+ .name = "interface",
+ .bin_attrs = if_bin_attrs,
+ .attrs = if_attrs,
+};
+
+static const struct attribute_group *attr_groups[] = {
+ &format_group,
+ &event_group,
+ &event_desc_group,
+ &event_long_desc_group,
+ &if_group,
+ &cpumask_attr_group,
+ NULL,
+};
+
+/*
+ * Start the process for a new H_GET_24x7_DATA hcall.
+ */
+static void init_24x7_request(struct hv_24x7_request_buffer *request_buffer,
+ struct hv_24x7_data_result_buffer *result_buffer)
+{
+
+ memset(request_buffer, 0, H24x7_DATA_BUFFER_SIZE);
+ memset(result_buffer, 0, H24x7_DATA_BUFFER_SIZE);
+
+ request_buffer->interface_version = interface_version;
+ /* memset above set request_buffer->num_requests to 0 */
+}
+
+/*
+ * Commit (i.e perform) the H_GET_24x7_DATA hcall using the data collected
+ * by 'init_24x7_request()' and 'add_event_to_24x7_request()'.
+ */
+static int make_24x7_request(struct hv_24x7_request_buffer *request_buffer,
+ struct hv_24x7_data_result_buffer *result_buffer)
+{
+ long ret;
+
+ /*
+ * NOTE: Due to variable number of array elements in request and
+ * result buffer(s), sizeof() is not reliable. Use the actual
+ * allocated buffer size, H24x7_DATA_BUFFER_SIZE.
+ */
+ ret = plpar_hcall_norets(H_GET_24X7_DATA,
+ virt_to_phys(request_buffer), H24x7_DATA_BUFFER_SIZE,
+ virt_to_phys(result_buffer), H24x7_DATA_BUFFER_SIZE);
+
+ if (ret) {
+ struct hv_24x7_request *req;
+
+ req = request_buffer->requests;
+ pr_notice_ratelimited("hcall failed: [%d %#x %#x %d] => ret 0x%lx (%ld) detail=0x%x failing ix=%x\n",
+ req->performance_domain, req->data_offset,
+ req->starting_ix, req->starting_lpar_ix,
+ ret, ret, result_buffer->detailed_rc,
+ result_buffer->failing_request_ix);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+/*
+ * Add the given @event to the next slot in the 24x7 request_buffer.
+ *
+ * Note that H_GET_24X7_DATA hcall allows reading several counters'
+ * values in a single HCALL. We expect the caller to add events to the
+ * request buffer one by one, make the HCALL and process the results.
+ */
+static int add_event_to_24x7_request(struct perf_event *event,
+ struct hv_24x7_request_buffer *request_buffer)
+{
+ u16 idx;
+ int i;
+ size_t req_size;
+ struct hv_24x7_request *req;
+
+ if (request_buffer->num_requests >=
+ max_num_requests(request_buffer->interface_version)) {
+ pr_devel("Too many requests for 24x7 HCALL %d\n",
+ request_buffer->num_requests);
+ return -EINVAL;
+ }
+
+ switch (event_get_domain(event)) {
+ case HV_PERF_DOMAIN_PHYS_CHIP:
+ idx = event_get_chip(event);
+ break;
+ case HV_PERF_DOMAIN_PHYS_CORE:
+ idx = event_get_core(event);
+ break;
+ default:
+ idx = event_get_vcpu(event);
+ }
+
+ req_size = H24x7_REQUEST_SIZE(request_buffer->interface_version);
+
+ i = request_buffer->num_requests++;
+ req = (void *) request_buffer->requests + i * req_size;
+
+ req->performance_domain = event_get_domain(event);
+ req->data_size = cpu_to_be16(8);
+ req->data_offset = cpu_to_be32(event_get_offset(event));
+ req->starting_lpar_ix = cpu_to_be16(event_get_lpar(event));
+ req->max_num_lpars = cpu_to_be16(1);
+ req->starting_ix = cpu_to_be16(idx);
+ req->max_ix = cpu_to_be16(1);
+
+ if (request_buffer->interface_version > 1) {
+ if (domain_needs_aggregation(req->performance_domain))
+ req->max_num_thread_groups = -1;
+ else if (req->performance_domain != HV_PERF_DOMAIN_PHYS_CHIP) {
+ req->starting_thread_group_ix = idx % 2;
+ req->max_num_thread_groups = 1;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * get_count_from_result - get event count from all result elements in result
+ *
+ * If the event corresponding to this result needs aggregation of the result
+ * element values, then this function does that.
+ *
+ * @event: Event associated with @res.
+ * @resb: Result buffer containing @res.
+ * @res: Result to work on.
+ * @countp: Output variable containing the event count.
+ * @next: Optional output variable pointing to the next result in @resb.
+ */
+static int get_count_from_result(struct perf_event *event,
+ struct hv_24x7_data_result_buffer *resb,
+ struct hv_24x7_result *res, u64 *countp,
+ struct hv_24x7_result **next)
+{
+ u16 num_elements = be16_to_cpu(res->num_elements_returned);
+ u16 data_size = be16_to_cpu(res->result_element_data_size);
+ unsigned int data_offset;
+ void *element_data;
+ int i;
+ u64 count;
+
+ /*
+ * We can bail out early if the result is empty.
+ */
+ if (!num_elements) {
+ pr_debug("Result of request %hhu is empty, nothing to do\n",
+ res->result_ix);
+
+ if (next)
+ *next = (struct hv_24x7_result *) res->elements;
+
+ return -ENODATA;
+ }
+
+ /*
+ * Since we always specify 1 as the maximum for the smallest resource
+ * we're requesting, there should to be only one element per result.
+ * Except when an event needs aggregation, in which case there are more.
+ */
+ if (num_elements != 1 &&
+ !domain_needs_aggregation(event_get_domain(event))) {
+ pr_err("Error: result of request %hhu has %hu elements\n",
+ res->result_ix, num_elements);
+
+ return -EIO;
+ }
+
+ if (data_size != sizeof(u64)) {
+ pr_debug("Error: result of request %hhu has data of %hu bytes\n",
+ res->result_ix, data_size);
+
+ return -ENOTSUPP;
+ }
+
+ if (resb->interface_version == 1)
+ data_offset = offsetof(struct hv_24x7_result_element_v1,
+ element_data);
+ else
+ data_offset = offsetof(struct hv_24x7_result_element_v2,
+ element_data);
+
+ /* Go through the result elements in the result. */
+ for (i = count = 0, element_data = res->elements + data_offset;
+ i < num_elements;
+ i++, element_data += data_size + data_offset)
+ count += be64_to_cpu(*((u64 *) element_data));
+
+ *countp = count;
+
+ /* The next result is after the last result element. */
+ if (next)
+ *next = element_data - data_offset;
+
+ return 0;
+}
+
+static int single_24x7_request(struct perf_event *event, u64 *count)
+{
+ int ret;
+ struct hv_24x7_request_buffer *request_buffer;
+ struct hv_24x7_data_result_buffer *result_buffer;
+
+ BUILD_BUG_ON(sizeof(*request_buffer) > 4096);
+ BUILD_BUG_ON(sizeof(*result_buffer) > 4096);
+
+ request_buffer = (void *)get_cpu_var(hv_24x7_reqb);
+ result_buffer = (void *)get_cpu_var(hv_24x7_resb);
+
+ init_24x7_request(request_buffer, result_buffer);
+
+ ret = add_event_to_24x7_request(event, request_buffer);
+ if (ret)
+ goto out;
+
+ ret = make_24x7_request(request_buffer, result_buffer);
+ if (ret)
+ goto out;
+
+ /* process result from hcall */
+ ret = get_count_from_result(event, result_buffer,
+ result_buffer->results, count, NULL);
+
+out:
+ put_cpu_var(hv_24x7_reqb);
+ put_cpu_var(hv_24x7_resb);
+ return ret;
+}
+
+
+static int h_24x7_event_init(struct perf_event *event)
+{
+ struct hv_perf_caps caps;
+ unsigned int domain;
+ unsigned long hret;
+ 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;
+ }
+
+ /* 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;
+ }
+
+ domain = event_get_domain(event);
+ if (domain == 0 || domain >= HV_PERF_DOMAIN_MAX) {
+ pr_devel("invalid domain %d\n", domain);
+ return -EINVAL;
+ }
+
+ hret = hv_perf_caps_get(&caps);
+ if (hret) {
+ pr_devel("could not get capabilities: rc=%ld\n", hret);
+ return -EIO;
+ }
+
+ /* Physical domains & other lpars require extra capabilities */
+ if (!caps.collect_privileged && (is_physical_domain(domain) ||
+ (event_get_lpar(event) != event_get_lpar_max()))) {
+ pr_devel("hv permissions disallow: is_physical_domain:%d, lpar=0x%llx\n",
+ is_physical_domain(domain),
+ event_get_lpar(event));
+ return -EACCES;
+ }
+
+ /* Get the initial value of the counter for this event */
+ if (single_24x7_request(event, &ct)) {
+ pr_devel("test hcall failed\n");
+ return -EIO;
+ }
+ (void)local64_xchg(&event->hw.prev_count, ct);
+
+ return 0;
+}
+
+static u64 h_24x7_get_value(struct perf_event *event)
+{
+ u64 ct;
+
+ if (single_24x7_request(event, &ct))
+ /* We checked this in event init, shouldn't fail here... */
+ return 0;
+
+ return ct;
+}
+
+static void update_event_count(struct perf_event *event, u64 now)
+{
+ s64 prev;
+
+ prev = local64_xchg(&event->hw.prev_count, now);
+ local64_add(now - prev, &event->count);
+}
+
+static void h_24x7_event_read(struct perf_event *event)
+{
+ u64 now;
+ struct hv_24x7_request_buffer *request_buffer;
+ struct hv_24x7_hw *h24x7hw;
+ int txn_flags;
+
+ txn_flags = __this_cpu_read(hv_24x7_txn_flags);
+
+ /*
+ * If in a READ transaction, add this counter to the list of
+ * counters to read during the next HCALL (i.e commit_txn()).
+ * If not in a READ transaction, go ahead and make the HCALL
+ * to read this counter by itself.
+ */
+
+ if (txn_flags & PERF_PMU_TXN_READ) {
+ int i;
+ int ret;
+
+ if (__this_cpu_read(hv_24x7_txn_err))
+ return;
+
+ request_buffer = (void *)get_cpu_var(hv_24x7_reqb);
+
+ ret = add_event_to_24x7_request(event, request_buffer);
+ if (ret) {
+ __this_cpu_write(hv_24x7_txn_err, ret);
+ } else {
+ /*
+ * Associate the event with the HCALL request index,
+ * so ->commit_txn() can quickly find/update count.
+ */
+ i = request_buffer->num_requests - 1;
+
+ h24x7hw = &get_cpu_var(hv_24x7_hw);
+ h24x7hw->events[i] = event;
+ put_cpu_var(h24x7hw);
+ }
+
+ put_cpu_var(hv_24x7_reqb);
+ } else {
+ now = h_24x7_get_value(event);
+ update_event_count(event, now);
+ }
+}
+
+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));
+}
+
+static void h_24x7_event_stop(struct perf_event *event, int flags)
+{
+ h_24x7_event_read(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;
+}
+
+/*
+ * 24x7 counters only support READ transactions. They are
+ * always counting and dont need/support ADD transactions.
+ * Cache the flags, but otherwise ignore transactions that
+ * are not PERF_PMU_TXN_READ.
+ */
+static void h_24x7_event_start_txn(struct pmu *pmu, unsigned int flags)
+{
+ struct hv_24x7_request_buffer *request_buffer;
+ struct hv_24x7_data_result_buffer *result_buffer;
+
+ /* We should not be called if we are already in a txn */
+ WARN_ON_ONCE(__this_cpu_read(hv_24x7_txn_flags));
+
+ __this_cpu_write(hv_24x7_txn_flags, flags);
+ if (flags & ~PERF_PMU_TXN_READ)
+ return;
+
+ request_buffer = (void *)get_cpu_var(hv_24x7_reqb);
+ result_buffer = (void *)get_cpu_var(hv_24x7_resb);
+
+ init_24x7_request(request_buffer, result_buffer);
+
+ put_cpu_var(hv_24x7_resb);
+ put_cpu_var(hv_24x7_reqb);
+}
+
+/*
+ * Clean up transaction state.
+ *
+ * NOTE: Ignore state of request and result buffers for now.
+ * We will initialize them during the next read/txn.
+ */
+static void reset_txn(void)
+{
+ __this_cpu_write(hv_24x7_txn_flags, 0);
+ __this_cpu_write(hv_24x7_txn_err, 0);
+}
+
+/*
+ * 24x7 counters only support READ transactions. They are always counting
+ * and dont need/support ADD transactions. Clear ->txn_flags but otherwise
+ * ignore transactions that are not of type PERF_PMU_TXN_READ.
+ *
+ * For READ transactions, submit all pending 24x7 requests (i.e requests
+ * that were queued by h_24x7_event_read()), to the hypervisor and update
+ * the event counts.
+ */
+static int h_24x7_event_commit_txn(struct pmu *pmu)
+{
+ struct hv_24x7_request_buffer *request_buffer;
+ struct hv_24x7_data_result_buffer *result_buffer;
+ struct hv_24x7_result *res, *next_res;
+ u64 count;
+ int i, ret, txn_flags;
+ struct hv_24x7_hw *h24x7hw;
+
+ txn_flags = __this_cpu_read(hv_24x7_txn_flags);
+ WARN_ON_ONCE(!txn_flags);
+
+ ret = 0;
+ if (txn_flags & ~PERF_PMU_TXN_READ)
+ goto out;
+
+ ret = __this_cpu_read(hv_24x7_txn_err);
+ if (ret)
+ goto out;
+
+ request_buffer = (void *)get_cpu_var(hv_24x7_reqb);
+ result_buffer = (void *)get_cpu_var(hv_24x7_resb);
+
+ ret = make_24x7_request(request_buffer, result_buffer);
+ if (ret)
+ goto put_reqb;
+
+ h24x7hw = &get_cpu_var(hv_24x7_hw);
+
+ /* Go through results in the result buffer to update event counts. */
+ for (i = 0, res = result_buffer->results;
+ i < result_buffer->num_results; i++, res = next_res) {
+ struct perf_event *event = h24x7hw->events[res->result_ix];
+
+ ret = get_count_from_result(event, result_buffer, res, &count,
+ &next_res);
+ if (ret)
+ break;
+
+ update_event_count(event, count);
+ }
+
+ put_cpu_var(hv_24x7_hw);
+
+put_reqb:
+ put_cpu_var(hv_24x7_resb);
+ put_cpu_var(hv_24x7_reqb);
+out:
+ reset_txn();
+ return ret;
+}
+
+/*
+ * 24x7 counters only support READ transactions. They are always counting
+ * and dont need/support ADD transactions. However, regardless of type
+ * of transaction, all we need to do is cleanup, so we don't have to check
+ * the type of transaction.
+ */
+static void h_24x7_event_cancel_txn(struct pmu *pmu)
+{
+ WARN_ON_ONCE(!__this_cpu_read(hv_24x7_txn_flags));
+ reset_txn();
+}
+
+static 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_stop,
+ .start = h_24x7_event_start,
+ .stop = h_24x7_event_stop,
+ .read = h_24x7_event_read,
+ .start_txn = h_24x7_event_start_txn,
+ .commit_txn = h_24x7_event_commit_txn,
+ .cancel_txn = h_24x7_event_cancel_txn,
+ .capabilities = PERF_PMU_CAP_NO_EXCLUDE,
+};
+
+static int ppc_hv_24x7_cpu_online(unsigned int cpu)
+{
+ if (cpumask_empty(&hv_24x7_cpumask))
+ cpumask_set_cpu(cpu, &hv_24x7_cpumask);
+
+ return 0;
+}
+
+static int ppc_hv_24x7_cpu_offline(unsigned int cpu)
+{
+ int target;
+
+ /* Check if exiting cpu is used for collecting 24x7 events */
+ if (!cpumask_test_and_clear_cpu(cpu, &hv_24x7_cpumask))
+ return 0;
+
+ /* Find a new cpu to collect 24x7 events */
+ target = cpumask_last(cpu_active_mask);
+
+ if (target < 0 || target >= nr_cpu_ids) {
+ pr_err("hv_24x7: CPU hotplug init failed\n");
+ return -1;
+ }
+
+ /* Migrate 24x7 events to the new target */
+ cpumask_set_cpu(target, &hv_24x7_cpumask);
+ perf_pmu_migrate_context(&h_24x7_pmu, cpu, target);
+
+ return 0;
+}
+
+static int hv_24x7_cpu_hotplug_init(void)
+{
+ return cpuhp_setup_state(CPUHP_AP_PERF_POWERPC_HV_24x7_ONLINE,
+ "perf/powerpc/hv_24x7:online",
+ ppc_hv_24x7_cpu_online,
+ ppc_hv_24x7_cpu_offline);
+}
+
+static int hv_24x7_init(void)
+{
+ int r;
+ unsigned long hret;
+ unsigned int pvr = mfspr(SPRN_PVR);
+ struct hv_perf_caps caps;
+
+ if (!firmware_has_feature(FW_FEATURE_LPAR)) {
+ pr_debug("not a virtualized system, not enabling\n");
+ return -ENODEV;
+ }
+
+ /* POWER8 only supports v1, while POWER9 only supports v2. */
+ if (PVR_VER(pvr) == PVR_POWER8)
+ interface_version = 1;
+ else {
+ interface_version = 2;
+
+ /* SMT8 in POWER9 needs to aggregate result elements. */
+ if (threads_per_core == 8)
+ aggregate_result_elements = true;
+ }
+
+ hret = hv_perf_caps_get(&caps);
+ if (hret) {
+ pr_debug("could not obtain capabilities, not enabling, rc=%ld\n",
+ hret);
+ return -ENODEV;
+ }
+
+ hv_page_cache = kmem_cache_create("hv-page-4096", 4096, 4096, 0, NULL);
+ if (!hv_page_cache)
+ return -ENOMEM;
+
+ /* sampling not supported */
+ h_24x7_pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
+
+ r = create_events_from_catalog(&event_group.attrs,
+ &event_desc_group.attrs,
+ &event_long_desc_group.attrs);
+
+ if (r)
+ return r;
+
+ /* init cpuhotplug */
+ r = hv_24x7_cpu_hotplug_init();
+ if (r)
+ return r;
+
+ r = perf_pmu_register(&h_24x7_pmu, h_24x7_pmu.name, -1);
+ if (r)
+ return r;
+
+ read_24x7_sys_info();
+
+ return 0;
+}
+
+device_initcall(hv_24x7_init);