/*
* Hypervisor supplied "24x7" performance counter support
*
* Author: Cody P Schafer <cody@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/rbtree.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <asm/firmware.h>
#include <asm/hvcall.h>
#include <asm/io.h>
#include <linux/byteorder/generic.h>
#include "hv-24x7.h"
#include "hv-24x7-catalog.h"
#include "hv-common.h"
static bool domain_is_valid(unsigned 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 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;
}
}
static const char *domain_name(unsigned 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 domain)
{
return is_physical_domain(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 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;
DEFINE_PER_CPU(int, hv_24x7_txn_flags);
DEFINE_PER_CPU(int, hv_24x7_txn_err);
struct hv_24x7_hw {
struct perf_event *events[255];
};
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
DEFINE_PER_CPU(char, hv_24x7_reqb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096);
DEFINE_PER_CPU(char, hv_24x7_resb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096);
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 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 nl = be16_to_cpu(ev->event_name_len);
__be16 *desc_len_ = (__be16 *)(ev->remainder + nl - 2);
unsigned 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 dl, ldl;
unsigned 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 unsigned 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 unsigned 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 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 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 ix,
struct hv_24x7_event_data *event,
unsigned 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 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 ct;
unsigned domain;
};
static int memord(const void *d1, size_t s1, const void *d2, size_t s2)
{
if (s1 < s2)
return 1;
if (s2 > s1)
return -1;
return memcmp(d1, d2, s1);
}
static int ev_uniq_ord(const void *v1, size_t s1, unsigned d1, const void *v2,
size_t s2, unsigned 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 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 = container_of(*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 it's 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;
}
#define MAX_4K (SIZE_MAX / 4096)
static int create_events_from_catalog(struct attribute ***events_,
struct attribute ***event_descs_,
struct attribute ***event_long_descs_)
{
unsigned 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;
uint32_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 %zu cl %zu eec %zu edo %zu edl %zu\n",
(size_t)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\n",
i + event_data_offs);
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 (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);
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)
{
unsigned 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) \
{ \
unsigned 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 struct bin_attribute *if_bin_attrs[] = {
&bin_attr_catalog,
NULL,
};
static struct attribute *if_attrs[] = {
&dev_attr_catalog_len.attr,
&dev_attr_catalog_version.attr,
&dev_attr_domains.attr,
NULL,
};
static 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,
NULL,
};
static void log_24x7_hcall(struct hv_24x7_request_buffer *request_buffer,
struct hv_24x7_data_result_buffer *result_buffer,
unsigned long ret)
{
struct hv_24x7_request *req;
req = &request_buffer->requests[0];
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);
}
/*
* 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, 4096);
memset(result_buffer, 0, 4096);
request_buffer->interface_version = HV_24X7_IF_VERSION_CURRENT;
/* 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)
{
unsigned 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)
log_24x7_hcall(request_buffer, result_buffer, ret);
return ret;
}
/*
* 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;
struct hv_24x7_request *req;
if (request_buffer->num_requests > 254) {
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);
}
i = request_buffer->num_requests++;
req = &request_buffer->requests[i];
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);
return 0;
}
static unsigned long single_24x7_request(struct perf_event *event, u64 *count)
{
unsigned long 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) {
log_24x7_hcall(request_buffer, result_buffer, ret);
goto out;
}
/* process result from hcall */
*count = be64_to_cpu(result_buffer->results[0].elements[0].element_data[0]);
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 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;
}
/* 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)
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 %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)
{
unsigned long ret;
u64 ct;
ret = single_24x7_request(event, &ct);
if (ret)
/* 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);
/*
* Clear the event count so we can compute the _change_
* in the 24x7 raw counter value at the end of the txn.
*
* Note that we could alternatively read the 24x7 value
* now and save its value in event->hw.prev_count. But
* that would require issuing a hcall, which would then
* defeat the purpose of using the txn interface.
*/
local64_set(&event->count, 0);
}
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 *resb;
struct perf_event *event;
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) {
log_24x7_hcall(request_buffer, result_buffer, ret);
goto put_reqb;
}
h24x7hw = &get_cpu_var(hv_24x7_hw);
/* Update event counts from hcall */
for (i = 0; i < request_buffer->num_requests; i++) {
resb = &result_buffer->results[i];
count = be64_to_cpu(resb->elements[0].element_data[0]);
event = h24x7hw->events[i];
h24x7hw->events[i] = NULL;
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,
};
static int hv_24x7_init(void)
{
int r;
unsigned long hret;
struct hv_perf_caps caps;
if (!firmware_has_feature(FW_FEATURE_LPAR)) {
pr_debug("not a virtualized system, not enabling\n");
return -ENODEV;
}
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;
r = perf_pmu_register(&h_24x7_pmu, h_24x7_pmu.name, -1);
if (r)
return r;
return 0;
}
device_initcall(hv_24x7_init);