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9d48c7afed
When a CPU is hotplugged while the perf stat -e cycles command is
running, a wrong (very large) value is displayed immediately after the
CPU removal:
Check the values, shouldn't be too high as in
time counts unit events
1.001101919 29261846 cycles
2.002454499 17523405 cycles
3.003659292 24361161 cycles
4.004816983 18446744073638406144 cycles
5.005671647 <not counted> cycles
...
The CPU hotplug off took place after 3 seconds.
The issue is the read of the event count value after 4 seconds when
the CPU is not available and the read of the counter returns an
error. This is treated as a counter value of zero. This results
in a very large value (0 - previous_value).
Fix this by detecting the hotplugged off CPU and report 0 instead
of a very large number.
Cc: stable@vger.kernel.org
Fixes: a029a4eab3
("s390/cpumf: Allow concurrent access for CPU Measurement Counter Facility")
Reported-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
1510 lines
44 KiB
C
1510 lines
44 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Performance event support for s390x - CPU-measurement Counter Facility
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*
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* Copyright IBM Corp. 2012, 2021
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* Author(s): Hendrik Brueckner <brueckner@linux.ibm.com>
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* Thomas Richter <tmricht@linux.ibm.com>
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*/
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#define KMSG_COMPONENT "cpum_cf"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/kernel.h>
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#include <linux/kernel_stat.h>
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#include <linux/percpu.h>
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#include <linux/notifier.h>
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#include <linux/init.h>
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#include <linux/export.h>
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#include <linux/miscdevice.h>
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#include <asm/cpu_mcf.h>
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#include <asm/hwctrset.h>
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#include <asm/debug.h>
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static unsigned int cfdiag_cpu_speed; /* CPU speed for CF_DIAG trailer */
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static debug_info_t *cf_dbg;
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#define CF_DIAG_CTRSET_DEF 0xfeef /* Counter set header mark */
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/* interval in seconds */
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/* Counter sets are stored as data stream in a page sized memory buffer and
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* exported to user space via raw data attached to the event sample data.
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* Each counter set starts with an eight byte header consisting of:
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* - a two byte eye catcher (0xfeef)
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* - a one byte counter set number
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* - a two byte counter set size (indicates the number of counters in this set)
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* - a three byte reserved value (must be zero) to make the header the same
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* size as a counter value.
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* All counter values are eight byte in size.
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*
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* All counter sets are followed by a 64 byte trailer.
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* The trailer consists of a:
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* - flag field indicating valid fields when corresponding bit set
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* - the counter facility first and second version number
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* - the CPU speed if nonzero
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* - the time stamp the counter sets have been collected
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* - the time of day (TOD) base value
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* - the machine type.
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*
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* The counter sets are saved when the process is prepared to be executed on a
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* CPU and saved again when the process is going to be removed from a CPU.
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* The difference of both counter sets are calculated and stored in the event
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* sample data area.
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*/
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struct cf_ctrset_entry { /* CPU-M CF counter set entry (8 byte) */
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unsigned int def:16; /* 0-15 Data Entry Format */
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unsigned int set:16; /* 16-31 Counter set identifier */
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unsigned int ctr:16; /* 32-47 Number of stored counters */
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unsigned int res1:16; /* 48-63 Reserved */
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};
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struct cf_trailer_entry { /* CPU-M CF_DIAG trailer (64 byte) */
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/* 0 - 7 */
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union {
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struct {
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unsigned int clock_base:1; /* TOD clock base set */
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unsigned int speed:1; /* CPU speed set */
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/* Measurement alerts */
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unsigned int mtda:1; /* Loss of MT ctr. data alert */
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unsigned int caca:1; /* Counter auth. change alert */
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unsigned int lcda:1; /* Loss of counter data alert */
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};
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unsigned long flags; /* 0-63 All indicators */
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};
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/* 8 - 15 */
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unsigned int cfvn:16; /* 64-79 Ctr First Version */
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unsigned int csvn:16; /* 80-95 Ctr Second Version */
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unsigned int cpu_speed:32; /* 96-127 CPU speed */
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/* 16 - 23 */
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unsigned long timestamp; /* 128-191 Timestamp (TOD) */
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/* 24 - 55 */
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union {
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struct {
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unsigned long progusage1;
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unsigned long progusage2;
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unsigned long progusage3;
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unsigned long tod_base;
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};
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unsigned long progusage[4];
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};
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/* 56 - 63 */
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unsigned int mach_type:16; /* Machine type */
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unsigned int res1:16; /* Reserved */
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unsigned int res2:32; /* Reserved */
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};
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/* Create the trailer data at the end of a page. */
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static void cfdiag_trailer(struct cf_trailer_entry *te)
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{
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struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
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struct cpuid cpuid;
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te->cfvn = cpuhw->info.cfvn; /* Counter version numbers */
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te->csvn = cpuhw->info.csvn;
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get_cpu_id(&cpuid); /* Machine type */
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te->mach_type = cpuid.machine;
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te->cpu_speed = cfdiag_cpu_speed;
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if (te->cpu_speed)
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te->speed = 1;
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te->clock_base = 1; /* Save clock base */
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te->tod_base = tod_clock_base.tod;
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te->timestamp = get_tod_clock_fast();
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}
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/* Read a counter set. The counter set number determines the counter set and
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* the CPUM-CF first and second version number determine the number of
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* available counters in each counter set.
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* Each counter set starts with header containing the counter set number and
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* the number of eight byte counters.
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*
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* The functions returns the number of bytes occupied by this counter set
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* including the header.
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* If there is no counter in the counter set, this counter set is useless and
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* zero is returned on this case.
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*
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* Note that the counter sets may not be enabled or active and the stcctm
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* instruction might return error 3. Depending on error_ok value this is ok,
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* for example when called from cpumf_pmu_start() call back function.
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*/
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static size_t cfdiag_getctrset(struct cf_ctrset_entry *ctrdata, int ctrset,
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size_t room, bool error_ok)
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{
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struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
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size_t ctrset_size, need = 0;
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int rc = 3; /* Assume write failure */
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ctrdata->def = CF_DIAG_CTRSET_DEF;
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ctrdata->set = ctrset;
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ctrdata->res1 = 0;
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ctrset_size = cpum_cf_ctrset_size(ctrset, &cpuhw->info);
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if (ctrset_size) { /* Save data */
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need = ctrset_size * sizeof(u64) + sizeof(*ctrdata);
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if (need <= room) {
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rc = ctr_stcctm(ctrset, ctrset_size,
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(u64 *)(ctrdata + 1));
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}
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if (rc != 3 || error_ok)
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ctrdata->ctr = ctrset_size;
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else
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need = 0;
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}
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debug_sprintf_event(cf_dbg, 3,
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"%s ctrset %d ctrset_size %zu cfvn %d csvn %d"
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" need %zd rc %d\n", __func__, ctrset, ctrset_size,
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cpuhw->info.cfvn, cpuhw->info.csvn, need, rc);
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return need;
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}
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static const u64 cpumf_ctr_ctl[CPUMF_CTR_SET_MAX] = {
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[CPUMF_CTR_SET_BASIC] = 0x02,
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[CPUMF_CTR_SET_USER] = 0x04,
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[CPUMF_CTR_SET_CRYPTO] = 0x08,
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[CPUMF_CTR_SET_EXT] = 0x01,
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[CPUMF_CTR_SET_MT_DIAG] = 0x20,
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};
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/* Read out all counter sets and save them in the provided data buffer.
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* The last 64 byte host an artificial trailer entry.
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*/
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static size_t cfdiag_getctr(void *data, size_t sz, unsigned long auth,
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bool error_ok)
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{
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struct cf_trailer_entry *trailer;
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size_t offset = 0, done;
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int i;
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memset(data, 0, sz);
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sz -= sizeof(*trailer); /* Always room for trailer */
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for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
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struct cf_ctrset_entry *ctrdata = data + offset;
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if (!(auth & cpumf_ctr_ctl[i]))
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continue; /* Counter set not authorized */
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done = cfdiag_getctrset(ctrdata, i, sz - offset, error_ok);
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offset += done;
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}
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trailer = data + offset;
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cfdiag_trailer(trailer);
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return offset + sizeof(*trailer);
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}
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/* Calculate the difference for each counter in a counter set. */
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static void cfdiag_diffctrset(u64 *pstart, u64 *pstop, int counters)
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{
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for (; --counters >= 0; ++pstart, ++pstop)
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if (*pstop >= *pstart)
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*pstop -= *pstart;
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else
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*pstop = *pstart - *pstop + 1;
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}
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/* Scan the counter sets and calculate the difference of each counter
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* in each set. The result is the increment of each counter during the
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* period the counter set has been activated.
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*
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* Return true on success.
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*/
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static int cfdiag_diffctr(struct cpu_cf_events *cpuhw, unsigned long auth)
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{
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struct cf_trailer_entry *trailer_start, *trailer_stop;
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struct cf_ctrset_entry *ctrstart, *ctrstop;
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size_t offset = 0;
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auth &= (1 << CPUMF_LCCTL_ENABLE_SHIFT) - 1;
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do {
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ctrstart = (struct cf_ctrset_entry *)(cpuhw->start + offset);
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ctrstop = (struct cf_ctrset_entry *)(cpuhw->stop + offset);
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if (memcmp(ctrstop, ctrstart, sizeof(*ctrstop))) {
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pr_err_once("cpum_cf_diag counter set compare error "
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"in set %i\n", ctrstart->set);
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return 0;
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}
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auth &= ~cpumf_ctr_ctl[ctrstart->set];
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if (ctrstart->def == CF_DIAG_CTRSET_DEF) {
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cfdiag_diffctrset((u64 *)(ctrstart + 1),
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(u64 *)(ctrstop + 1), ctrstart->ctr);
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offset += ctrstart->ctr * sizeof(u64) +
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sizeof(*ctrstart);
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}
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} while (ctrstart->def && auth);
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/* Save time_stamp from start of event in stop's trailer */
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trailer_start = (struct cf_trailer_entry *)(cpuhw->start + offset);
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trailer_stop = (struct cf_trailer_entry *)(cpuhw->stop + offset);
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trailer_stop->progusage[0] = trailer_start->timestamp;
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return 1;
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}
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static enum cpumf_ctr_set get_counter_set(u64 event)
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{
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int set = CPUMF_CTR_SET_MAX;
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if (event < 32)
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set = CPUMF_CTR_SET_BASIC;
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else if (event < 64)
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set = CPUMF_CTR_SET_USER;
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else if (event < 128)
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set = CPUMF_CTR_SET_CRYPTO;
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else if (event < 288)
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set = CPUMF_CTR_SET_EXT;
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else if (event >= 448 && event < 496)
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set = CPUMF_CTR_SET_MT_DIAG;
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return set;
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}
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static int validate_ctr_version(const struct hw_perf_event *hwc,
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enum cpumf_ctr_set set)
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{
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struct cpu_cf_events *cpuhw;
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int err = 0;
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u16 mtdiag_ctl;
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cpuhw = &get_cpu_var(cpu_cf_events);
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/* check required version for counter sets */
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switch (set) {
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case CPUMF_CTR_SET_BASIC:
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case CPUMF_CTR_SET_USER:
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if (cpuhw->info.cfvn < 1)
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err = -EOPNOTSUPP;
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break;
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case CPUMF_CTR_SET_CRYPTO:
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if ((cpuhw->info.csvn >= 1 && cpuhw->info.csvn <= 5 &&
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hwc->config > 79) ||
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(cpuhw->info.csvn >= 6 && hwc->config > 83))
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err = -EOPNOTSUPP;
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break;
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case CPUMF_CTR_SET_EXT:
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if (cpuhw->info.csvn < 1)
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err = -EOPNOTSUPP;
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if ((cpuhw->info.csvn == 1 && hwc->config > 159) ||
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(cpuhw->info.csvn == 2 && hwc->config > 175) ||
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(cpuhw->info.csvn >= 3 && cpuhw->info.csvn <= 5
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&& hwc->config > 255) ||
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(cpuhw->info.csvn >= 6 && hwc->config > 287))
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err = -EOPNOTSUPP;
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break;
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case CPUMF_CTR_SET_MT_DIAG:
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if (cpuhw->info.csvn <= 3)
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err = -EOPNOTSUPP;
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/*
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* MT-diagnostic counters are read-only. The counter set
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* is automatically enabled and activated on all CPUs with
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* multithreading (SMT). Deactivation of multithreading
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* also disables the counter set. State changes are ignored
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* by lcctl(). Because Linux controls SMT enablement through
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* a kernel parameter only, the counter set is either disabled
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* or enabled and active.
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*
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* Thus, the counters can only be used if SMT is on and the
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* counter set is enabled and active.
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*/
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mtdiag_ctl = cpumf_ctr_ctl[CPUMF_CTR_SET_MT_DIAG];
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if (!((cpuhw->info.auth_ctl & mtdiag_ctl) &&
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(cpuhw->info.enable_ctl & mtdiag_ctl) &&
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(cpuhw->info.act_ctl & mtdiag_ctl)))
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err = -EOPNOTSUPP;
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break;
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case CPUMF_CTR_SET_MAX:
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err = -EOPNOTSUPP;
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}
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put_cpu_var(cpu_cf_events);
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return err;
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}
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static int validate_ctr_auth(const struct hw_perf_event *hwc)
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{
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struct cpu_cf_events *cpuhw;
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int err = 0;
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cpuhw = &get_cpu_var(cpu_cf_events);
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/* Check authorization for cpu counter sets.
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* If the particular CPU counter set is not authorized,
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* return with -ENOENT in order to fall back to other
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* PMUs that might suffice the event request.
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*/
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if (!(hwc->config_base & cpuhw->info.auth_ctl))
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err = -ENOENT;
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put_cpu_var(cpu_cf_events);
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return err;
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}
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/*
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* Change the CPUMF state to active.
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* Enable and activate the CPU-counter sets according
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* to the per-cpu control state.
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*/
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static void cpumf_pmu_enable(struct pmu *pmu)
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{
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struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
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int err;
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if (cpuhw->flags & PMU_F_ENABLED)
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return;
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err = lcctl(cpuhw->state | cpuhw->dev_state);
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if (err) {
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pr_err("Enabling the performance measuring unit "
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"failed with rc=%x\n", err);
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return;
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}
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cpuhw->flags |= PMU_F_ENABLED;
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}
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/*
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* Change the CPUMF state to inactive.
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* Disable and enable (inactive) the CPU-counter sets according
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* to the per-cpu control state.
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*/
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static void cpumf_pmu_disable(struct pmu *pmu)
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{
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struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
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int err;
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u64 inactive;
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if (!(cpuhw->flags & PMU_F_ENABLED))
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return;
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inactive = cpuhw->state & ~((1 << CPUMF_LCCTL_ENABLE_SHIFT) - 1);
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inactive |= cpuhw->dev_state;
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err = lcctl(inactive);
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if (err) {
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pr_err("Disabling the performance measuring unit "
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"failed with rc=%x\n", err);
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return;
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}
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cpuhw->flags &= ~PMU_F_ENABLED;
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}
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/* Number of perf events counting hardware events */
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static atomic_t num_events = ATOMIC_INIT(0);
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/* Used to avoid races in calling reserve/release_cpumf_hardware */
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static DEFINE_MUTEX(pmc_reserve_mutex);
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/* Release the PMU if event is the last perf event */
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static void hw_perf_event_destroy(struct perf_event *event)
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{
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if (!atomic_add_unless(&num_events, -1, 1)) {
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mutex_lock(&pmc_reserve_mutex);
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if (atomic_dec_return(&num_events) == 0)
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__kernel_cpumcf_end();
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mutex_unlock(&pmc_reserve_mutex);
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}
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}
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/* CPUMF <-> perf event mappings for kernel+userspace (basic set) */
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static const int cpumf_generic_events_basic[] = {
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[PERF_COUNT_HW_CPU_CYCLES] = 0,
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[PERF_COUNT_HW_INSTRUCTIONS] = 1,
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[PERF_COUNT_HW_CACHE_REFERENCES] = -1,
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[PERF_COUNT_HW_CACHE_MISSES] = -1,
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[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = -1,
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[PERF_COUNT_HW_BRANCH_MISSES] = -1,
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[PERF_COUNT_HW_BUS_CYCLES] = -1,
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};
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/* CPUMF <-> perf event mappings for userspace (problem-state set) */
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static const int cpumf_generic_events_user[] = {
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[PERF_COUNT_HW_CPU_CYCLES] = 32,
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[PERF_COUNT_HW_INSTRUCTIONS] = 33,
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[PERF_COUNT_HW_CACHE_REFERENCES] = -1,
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[PERF_COUNT_HW_CACHE_MISSES] = -1,
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[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = -1,
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[PERF_COUNT_HW_BRANCH_MISSES] = -1,
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[PERF_COUNT_HW_BUS_CYCLES] = -1,
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};
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static void cpumf_hw_inuse(void)
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{
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mutex_lock(&pmc_reserve_mutex);
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if (atomic_inc_return(&num_events) == 1)
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__kernel_cpumcf_begin();
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mutex_unlock(&pmc_reserve_mutex);
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}
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static int __hw_perf_event_init(struct perf_event *event, unsigned int type)
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{
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struct perf_event_attr *attr = &event->attr;
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struct hw_perf_event *hwc = &event->hw;
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enum cpumf_ctr_set set;
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int err = 0;
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|
u64 ev;
|
|
|
|
switch (type) {
|
|
case PERF_TYPE_RAW:
|
|
/* Raw events are used to access counters directly,
|
|
* hence do not permit excludes */
|
|
if (attr->exclude_kernel || attr->exclude_user ||
|
|
attr->exclude_hv)
|
|
return -EOPNOTSUPP;
|
|
ev = attr->config;
|
|
break;
|
|
|
|
case PERF_TYPE_HARDWARE:
|
|
if (is_sampling_event(event)) /* No sampling support */
|
|
return -ENOENT;
|
|
ev = attr->config;
|
|
/* Count user space (problem-state) only */
|
|
if (!attr->exclude_user && attr->exclude_kernel) {
|
|
if (ev >= ARRAY_SIZE(cpumf_generic_events_user))
|
|
return -EOPNOTSUPP;
|
|
ev = cpumf_generic_events_user[ev];
|
|
|
|
/* No support for kernel space counters only */
|
|
} else if (!attr->exclude_kernel && attr->exclude_user) {
|
|
return -EOPNOTSUPP;
|
|
} else { /* Count user and kernel space */
|
|
if (ev >= ARRAY_SIZE(cpumf_generic_events_basic))
|
|
return -EOPNOTSUPP;
|
|
ev = cpumf_generic_events_basic[ev];
|
|
}
|
|
break;
|
|
|
|
default:
|
|
return -ENOENT;
|
|
}
|
|
|
|
if (ev == -1)
|
|
return -ENOENT;
|
|
|
|
if (ev > PERF_CPUM_CF_MAX_CTR)
|
|
return -ENOENT;
|
|
|
|
/* Obtain the counter set to which the specified counter belongs */
|
|
set = get_counter_set(ev);
|
|
switch (set) {
|
|
case CPUMF_CTR_SET_BASIC:
|
|
case CPUMF_CTR_SET_USER:
|
|
case CPUMF_CTR_SET_CRYPTO:
|
|
case CPUMF_CTR_SET_EXT:
|
|
case CPUMF_CTR_SET_MT_DIAG:
|
|
/*
|
|
* Use the hardware perf event structure to store the
|
|
* counter number in the 'config' member and the counter
|
|
* set number in the 'config_base' as bit mask.
|
|
* It is later used to enable/disable the counter(s).
|
|
*/
|
|
hwc->config = ev;
|
|
hwc->config_base = cpumf_ctr_ctl[set];
|
|
break;
|
|
case CPUMF_CTR_SET_MAX:
|
|
/* The counter could not be associated to a counter set */
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Initialize for using the CPU-measurement counter facility */
|
|
cpumf_hw_inuse();
|
|
event->destroy = hw_perf_event_destroy;
|
|
|
|
/* Finally, validate version and authorization of the counter set */
|
|
err = validate_ctr_auth(hwc);
|
|
if (!err)
|
|
err = validate_ctr_version(hwc, set);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int cpumf_pmu_event_init(struct perf_event *event)
|
|
{
|
|
unsigned int type = event->attr.type;
|
|
int err;
|
|
|
|
if (type == PERF_TYPE_HARDWARE || type == PERF_TYPE_RAW)
|
|
err = __hw_perf_event_init(event, type);
|
|
else if (event->pmu->type == type)
|
|
/* Registered as unknown PMU */
|
|
err = __hw_perf_event_init(event, PERF_TYPE_RAW);
|
|
else
|
|
return -ENOENT;
|
|
|
|
if (unlikely(err) && event->destroy)
|
|
event->destroy(event);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int hw_perf_event_reset(struct perf_event *event)
|
|
{
|
|
u64 prev, new;
|
|
int err;
|
|
|
|
do {
|
|
prev = local64_read(&event->hw.prev_count);
|
|
err = ecctr(event->hw.config, &new);
|
|
if (err) {
|
|
if (err != 3)
|
|
break;
|
|
/* The counter is not (yet) available. This
|
|
* might happen if the counter set to which
|
|
* this counter belongs is in the disabled
|
|
* state.
|
|
*/
|
|
new = 0;
|
|
}
|
|
} while (local64_cmpxchg(&event->hw.prev_count, prev, new) != prev);
|
|
|
|
return err;
|
|
}
|
|
|
|
static void hw_perf_event_update(struct perf_event *event)
|
|
{
|
|
u64 prev, new, delta;
|
|
int err;
|
|
|
|
do {
|
|
prev = local64_read(&event->hw.prev_count);
|
|
err = ecctr(event->hw.config, &new);
|
|
if (err)
|
|
return;
|
|
} while (local64_cmpxchg(&event->hw.prev_count, prev, new) != prev);
|
|
|
|
delta = (prev <= new) ? new - prev
|
|
: (-1ULL - prev) + new + 1; /* overflow */
|
|
local64_add(delta, &event->count);
|
|
}
|
|
|
|
static void cpumf_pmu_read(struct perf_event *event)
|
|
{
|
|
if (event->hw.state & PERF_HES_STOPPED)
|
|
return;
|
|
|
|
hw_perf_event_update(event);
|
|
}
|
|
|
|
static void cpumf_pmu_start(struct perf_event *event, int flags)
|
|
{
|
|
struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
|
|
struct hw_perf_event *hwc = &event->hw;
|
|
int i;
|
|
|
|
if (!(hwc->state & PERF_HES_STOPPED))
|
|
return;
|
|
|
|
hwc->state = 0;
|
|
|
|
/* (Re-)enable and activate the counter set */
|
|
ctr_set_enable(&cpuhw->state, hwc->config_base);
|
|
ctr_set_start(&cpuhw->state, hwc->config_base);
|
|
|
|
/* The counter set to which this counter belongs can be already active.
|
|
* Because all counters in a set are active, the event->hw.prev_count
|
|
* needs to be synchronized. At this point, the counter set can be in
|
|
* the inactive or disabled state.
|
|
*/
|
|
if (hwc->config == PERF_EVENT_CPUM_CF_DIAG) {
|
|
cpuhw->usedss = cfdiag_getctr(cpuhw->start,
|
|
sizeof(cpuhw->start),
|
|
hwc->config_base, true);
|
|
} else {
|
|
hw_perf_event_reset(event);
|
|
}
|
|
|
|
/* Increment refcount for counter sets */
|
|
for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i)
|
|
if ((hwc->config_base & cpumf_ctr_ctl[i]))
|
|
atomic_inc(&cpuhw->ctr_set[i]);
|
|
}
|
|
|
|
/* Create perf event sample with the counter sets as raw data. The sample
|
|
* is then pushed to the event subsystem and the function checks for
|
|
* possible event overflows. If an event overflow occurs, the PMU is
|
|
* stopped.
|
|
*
|
|
* Return non-zero if an event overflow occurred.
|
|
*/
|
|
static int cfdiag_push_sample(struct perf_event *event,
|
|
struct cpu_cf_events *cpuhw)
|
|
{
|
|
struct perf_sample_data data;
|
|
struct perf_raw_record raw;
|
|
struct pt_regs regs;
|
|
int overflow;
|
|
|
|
/* Setup perf sample */
|
|
perf_sample_data_init(&data, 0, event->hw.last_period);
|
|
memset(®s, 0, sizeof(regs));
|
|
memset(&raw, 0, sizeof(raw));
|
|
|
|
if (event->attr.sample_type & PERF_SAMPLE_CPU)
|
|
data.cpu_entry.cpu = event->cpu;
|
|
if (event->attr.sample_type & PERF_SAMPLE_RAW) {
|
|
raw.frag.size = cpuhw->usedss;
|
|
raw.frag.data = cpuhw->stop;
|
|
raw.size = raw.frag.size;
|
|
data.raw = &raw;
|
|
}
|
|
|
|
overflow = perf_event_overflow(event, &data, ®s);
|
|
debug_sprintf_event(cf_dbg, 3,
|
|
"%s event %#llx sample_type %#llx raw %d ov %d\n",
|
|
__func__, event->hw.config,
|
|
event->attr.sample_type, raw.size, overflow);
|
|
if (overflow)
|
|
event->pmu->stop(event, 0);
|
|
|
|
perf_event_update_userpage(event);
|
|
return overflow;
|
|
}
|
|
|
|
static void cpumf_pmu_stop(struct perf_event *event, int flags)
|
|
{
|
|
struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
|
|
struct hw_perf_event *hwc = &event->hw;
|
|
int i;
|
|
|
|
if (!(hwc->state & PERF_HES_STOPPED)) {
|
|
/* Decrement reference count for this counter set and if this
|
|
* is the last used counter in the set, clear activation
|
|
* control and set the counter set state to inactive.
|
|
*/
|
|
for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
|
|
if (!(hwc->config_base & cpumf_ctr_ctl[i]))
|
|
continue;
|
|
if (!atomic_dec_return(&cpuhw->ctr_set[i]))
|
|
ctr_set_stop(&cpuhw->state, cpumf_ctr_ctl[i]);
|
|
}
|
|
hwc->state |= PERF_HES_STOPPED;
|
|
}
|
|
|
|
if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
|
|
if (hwc->config == PERF_EVENT_CPUM_CF_DIAG) {
|
|
local64_inc(&event->count);
|
|
cpuhw->usedss = cfdiag_getctr(cpuhw->stop,
|
|
sizeof(cpuhw->stop),
|
|
event->hw.config_base,
|
|
false);
|
|
if (cfdiag_diffctr(cpuhw, event->hw.config_base))
|
|
cfdiag_push_sample(event, cpuhw);
|
|
} else if (cpuhw->flags & PMU_F_RESERVED) {
|
|
/* Only update when PMU not hotplugged off */
|
|
hw_perf_event_update(event);
|
|
}
|
|
hwc->state |= PERF_HES_UPTODATE;
|
|
}
|
|
}
|
|
|
|
static int cpumf_pmu_add(struct perf_event *event, int flags)
|
|
{
|
|
struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
|
|
|
|
ctr_set_enable(&cpuhw->state, event->hw.config_base);
|
|
event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
|
|
|
|
if (flags & PERF_EF_START)
|
|
cpumf_pmu_start(event, PERF_EF_RELOAD);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void cpumf_pmu_del(struct perf_event *event, int flags)
|
|
{
|
|
struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
|
|
int i;
|
|
|
|
cpumf_pmu_stop(event, PERF_EF_UPDATE);
|
|
|
|
/* Check if any counter in the counter set is still used. If not used,
|
|
* change the counter set to the disabled state. This also clears the
|
|
* content of all counters in the set.
|
|
*
|
|
* When a new perf event has been added but not yet started, this can
|
|
* clear enable control and resets all counters in a set. Therefore,
|
|
* cpumf_pmu_start() always has to reenable a counter set.
|
|
*/
|
|
for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i)
|
|
if (!atomic_read(&cpuhw->ctr_set[i]))
|
|
ctr_set_disable(&cpuhw->state, cpumf_ctr_ctl[i]);
|
|
}
|
|
|
|
/* Performance monitoring unit for s390x */
|
|
static struct pmu cpumf_pmu = {
|
|
.task_ctx_nr = perf_sw_context,
|
|
.capabilities = PERF_PMU_CAP_NO_INTERRUPT,
|
|
.pmu_enable = cpumf_pmu_enable,
|
|
.pmu_disable = cpumf_pmu_disable,
|
|
.event_init = cpumf_pmu_event_init,
|
|
.add = cpumf_pmu_add,
|
|
.del = cpumf_pmu_del,
|
|
.start = cpumf_pmu_start,
|
|
.stop = cpumf_pmu_stop,
|
|
.read = cpumf_pmu_read,
|
|
};
|
|
|
|
static int cfset_init(void);
|
|
static int __init cpumf_pmu_init(void)
|
|
{
|
|
int rc;
|
|
|
|
if (!kernel_cpumcf_avail())
|
|
return -ENODEV;
|
|
|
|
/* Setup s390dbf facility */
|
|
cf_dbg = debug_register(KMSG_COMPONENT, 2, 1, 128);
|
|
if (!cf_dbg) {
|
|
pr_err("Registration of s390dbf(cpum_cf) failed\n");
|
|
return -ENOMEM;
|
|
}
|
|
debug_register_view(cf_dbg, &debug_sprintf_view);
|
|
|
|
cpumf_pmu.attr_groups = cpumf_cf_event_group();
|
|
rc = perf_pmu_register(&cpumf_pmu, "cpum_cf", -1);
|
|
if (rc) {
|
|
debug_unregister_view(cf_dbg, &debug_sprintf_view);
|
|
debug_unregister(cf_dbg);
|
|
pr_err("Registering the cpum_cf PMU failed with rc=%i\n", rc);
|
|
} else if (stccm_avail()) { /* Setup counter set device */
|
|
cfset_init();
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/* Support for the CPU Measurement Facility counter set extraction using
|
|
* device /dev/hwctr. This allows user space programs to extract complete
|
|
* counter set via normal file operations.
|
|
*/
|
|
|
|
static atomic_t cfset_opencnt = ATOMIC_INIT(0); /* Access count */
|
|
static DEFINE_MUTEX(cfset_ctrset_mutex);/* Synchronize access to hardware */
|
|
struct cfset_call_on_cpu_parm { /* Parm struct for smp_call_on_cpu */
|
|
unsigned int sets; /* Counter set bit mask */
|
|
atomic_t cpus_ack; /* # CPUs successfully executed func */
|
|
};
|
|
|
|
static struct cfset_session { /* CPUs and counter set bit mask */
|
|
struct list_head head; /* Head of list of active processes */
|
|
} cfset_session = {
|
|
.head = LIST_HEAD_INIT(cfset_session.head)
|
|
};
|
|
|
|
struct cfset_request { /* CPUs and counter set bit mask */
|
|
unsigned long ctrset; /* Bit mask of counter set to read */
|
|
cpumask_t mask; /* CPU mask to read from */
|
|
struct list_head node; /* Chain to cfset_session.head */
|
|
};
|
|
|
|
static void cfset_session_init(void)
|
|
{
|
|
INIT_LIST_HEAD(&cfset_session.head);
|
|
}
|
|
|
|
/* Remove current request from global bookkeeping. Maintain a counter set bit
|
|
* mask on a per CPU basis.
|
|
* Done in process context under mutex protection.
|
|
*/
|
|
static void cfset_session_del(struct cfset_request *p)
|
|
{
|
|
list_del(&p->node);
|
|
}
|
|
|
|
/* Add current request to global bookkeeping. Maintain a counter set bit mask
|
|
* on a per CPU basis.
|
|
* Done in process context under mutex protection.
|
|
*/
|
|
static void cfset_session_add(struct cfset_request *p)
|
|
{
|
|
list_add(&p->node, &cfset_session.head);
|
|
}
|
|
|
|
/* The /dev/hwctr device access uses PMU_F_IN_USE to mark the device access
|
|
* path is currently used.
|
|
* The cpu_cf_events::dev_state is used to denote counter sets in use by this
|
|
* interface. It is always or'ed in. If this interface is not active, its
|
|
* value is zero and no additional counter sets will be included.
|
|
*
|
|
* The cpu_cf_events::state is used by the perf_event_open SVC and remains
|
|
* unchanged.
|
|
*
|
|
* perf_pmu_enable() and perf_pmu_enable() and its call backs
|
|
* cpumf_pmu_enable() and cpumf_pmu_disable() are called by the
|
|
* performance measurement subsystem to enable per process
|
|
* CPU Measurement counter facility.
|
|
* The XXX_enable() and XXX_disable functions are used to turn off
|
|
* x86 performance monitoring interrupt (PMI) during scheduling.
|
|
* s390 uses these calls to temporarily stop and resume the active CPU
|
|
* counters sets during scheduling.
|
|
*
|
|
* We do allow concurrent access of perf_event_open() SVC and /dev/hwctr
|
|
* device access. The perf_event_open() SVC interface makes a lot of effort
|
|
* to only run the counters while the calling process is actively scheduled
|
|
* to run.
|
|
* When /dev/hwctr interface is also used at the same time, the counter sets
|
|
* will keep running, even when the process is scheduled off a CPU.
|
|
* However this is not a problem and does not lead to wrong counter values
|
|
* for the perf_event_open() SVC. The current counter value will be recorded
|
|
* during schedule-in. At schedule-out time the current counter value is
|
|
* extracted again and the delta is calculated and added to the event.
|
|
*/
|
|
/* Stop all counter sets via ioctl interface */
|
|
static void cfset_ioctl_off(void *parm)
|
|
{
|
|
struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
|
|
struct cfset_call_on_cpu_parm *p = parm;
|
|
int rc;
|
|
|
|
/* Check if any counter set used by /dev/hwc */
|
|
for (rc = CPUMF_CTR_SET_BASIC; rc < CPUMF_CTR_SET_MAX; ++rc)
|
|
if ((p->sets & cpumf_ctr_ctl[rc])) {
|
|
if (!atomic_dec_return(&cpuhw->ctr_set[rc])) {
|
|
ctr_set_disable(&cpuhw->dev_state,
|
|
cpumf_ctr_ctl[rc]);
|
|
ctr_set_stop(&cpuhw->dev_state,
|
|
cpumf_ctr_ctl[rc]);
|
|
}
|
|
}
|
|
/* Keep perf_event_open counter sets */
|
|
rc = lcctl(cpuhw->dev_state | cpuhw->state);
|
|
if (rc)
|
|
pr_err("Counter set stop %#llx of /dev/%s failed rc=%i\n",
|
|
cpuhw->state, S390_HWCTR_DEVICE, rc);
|
|
if (!cpuhw->dev_state)
|
|
cpuhw->flags &= ~PMU_F_IN_USE;
|
|
debug_sprintf_event(cf_dbg, 4, "%s rc %d state %#llx dev_state %#llx\n",
|
|
__func__, rc, cpuhw->state, cpuhw->dev_state);
|
|
}
|
|
|
|
/* Start counter sets on particular CPU */
|
|
static void cfset_ioctl_on(void *parm)
|
|
{
|
|
struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
|
|
struct cfset_call_on_cpu_parm *p = parm;
|
|
int rc;
|
|
|
|
cpuhw->flags |= PMU_F_IN_USE;
|
|
ctr_set_enable(&cpuhw->dev_state, p->sets);
|
|
ctr_set_start(&cpuhw->dev_state, p->sets);
|
|
for (rc = CPUMF_CTR_SET_BASIC; rc < CPUMF_CTR_SET_MAX; ++rc)
|
|
if ((p->sets & cpumf_ctr_ctl[rc]))
|
|
atomic_inc(&cpuhw->ctr_set[rc]);
|
|
rc = lcctl(cpuhw->dev_state | cpuhw->state); /* Start counter sets */
|
|
if (!rc)
|
|
atomic_inc(&p->cpus_ack);
|
|
else
|
|
pr_err("Counter set start %#llx of /dev/%s failed rc=%i\n",
|
|
cpuhw->dev_state | cpuhw->state, S390_HWCTR_DEVICE, rc);
|
|
debug_sprintf_event(cf_dbg, 4, "%s rc %d state %#llx dev_state %#llx\n",
|
|
__func__, rc, cpuhw->state, cpuhw->dev_state);
|
|
}
|
|
|
|
static void cfset_release_cpu(void *p)
|
|
{
|
|
struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
|
|
int rc;
|
|
|
|
debug_sprintf_event(cf_dbg, 4, "%s state %#llx dev_state %#llx\n",
|
|
__func__, cpuhw->state, cpuhw->dev_state);
|
|
cpuhw->dev_state = 0;
|
|
rc = lcctl(cpuhw->state); /* Keep perf_event_open counter sets */
|
|
if (rc)
|
|
pr_err("Counter set release %#llx of /dev/%s failed rc=%i\n",
|
|
cpuhw->state, S390_HWCTR_DEVICE, rc);
|
|
}
|
|
|
|
/* This modifies the process CPU mask to adopt it to the currently online
|
|
* CPUs. Offline CPUs can not be addresses. This call terminates the access
|
|
* and is usually followed by close() or a new iotcl(..., START, ...) which
|
|
* creates a new request structure.
|
|
*/
|
|
static void cfset_all_stop(struct cfset_request *req)
|
|
{
|
|
struct cfset_call_on_cpu_parm p = {
|
|
.sets = req->ctrset,
|
|
};
|
|
|
|
cpumask_and(&req->mask, &req->mask, cpu_online_mask);
|
|
on_each_cpu_mask(&req->mask, cfset_ioctl_off, &p, 1);
|
|
}
|
|
|
|
/* Release function is also called when application gets terminated without
|
|
* doing a proper ioctl(..., S390_HWCTR_STOP, ...) command.
|
|
*/
|
|
static int cfset_release(struct inode *inode, struct file *file)
|
|
{
|
|
mutex_lock(&cfset_ctrset_mutex);
|
|
/* Open followed by close/exit has no private_data */
|
|
if (file->private_data) {
|
|
cfset_all_stop(file->private_data);
|
|
cfset_session_del(file->private_data);
|
|
kfree(file->private_data);
|
|
file->private_data = NULL;
|
|
}
|
|
if (!atomic_dec_return(&cfset_opencnt))
|
|
on_each_cpu(cfset_release_cpu, NULL, 1);
|
|
mutex_unlock(&cfset_ctrset_mutex);
|
|
|
|
hw_perf_event_destroy(NULL);
|
|
return 0;
|
|
}
|
|
|
|
static int cfset_open(struct inode *inode, struct file *file)
|
|
{
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
mutex_lock(&cfset_ctrset_mutex);
|
|
if (atomic_inc_return(&cfset_opencnt) == 1)
|
|
cfset_session_init();
|
|
mutex_unlock(&cfset_ctrset_mutex);
|
|
|
|
cpumf_hw_inuse();
|
|
file->private_data = NULL;
|
|
/* nonseekable_open() never fails */
|
|
return nonseekable_open(inode, file);
|
|
}
|
|
|
|
static int cfset_all_start(struct cfset_request *req)
|
|
{
|
|
struct cfset_call_on_cpu_parm p = {
|
|
.sets = req->ctrset,
|
|
.cpus_ack = ATOMIC_INIT(0),
|
|
};
|
|
cpumask_var_t mask;
|
|
int rc = 0;
|
|
|
|
if (!alloc_cpumask_var(&mask, GFP_KERNEL))
|
|
return -ENOMEM;
|
|
cpumask_and(mask, &req->mask, cpu_online_mask);
|
|
on_each_cpu_mask(mask, cfset_ioctl_on, &p, 1);
|
|
if (atomic_read(&p.cpus_ack) != cpumask_weight(mask)) {
|
|
on_each_cpu_mask(mask, cfset_ioctl_off, &p, 1);
|
|
rc = -EIO;
|
|
debug_sprintf_event(cf_dbg, 4, "%s CPUs missing", __func__);
|
|
}
|
|
free_cpumask_var(mask);
|
|
return rc;
|
|
}
|
|
|
|
|
|
/* Return the maximum required space for all possible CPUs in case one
|
|
* CPU will be onlined during the START, READ, STOP cycles.
|
|
* To find out the size of the counter sets, any one CPU will do. They
|
|
* all have the same counter sets.
|
|
*/
|
|
static size_t cfset_needspace(unsigned int sets)
|
|
{
|
|
struct cpu_cf_events *cpuhw = get_cpu_ptr(&cpu_cf_events);
|
|
size_t bytes = 0;
|
|
int i;
|
|
|
|
for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
|
|
if (!(sets & cpumf_ctr_ctl[i]))
|
|
continue;
|
|
bytes += cpum_cf_ctrset_size(i, &cpuhw->info) * sizeof(u64) +
|
|
sizeof(((struct s390_ctrset_setdata *)0)->set) +
|
|
sizeof(((struct s390_ctrset_setdata *)0)->no_cnts);
|
|
}
|
|
bytes = sizeof(((struct s390_ctrset_read *)0)->no_cpus) + nr_cpu_ids *
|
|
(bytes + sizeof(((struct s390_ctrset_cpudata *)0)->cpu_nr) +
|
|
sizeof(((struct s390_ctrset_cpudata *)0)->no_sets));
|
|
put_cpu_ptr(&cpu_cf_events);
|
|
return bytes;
|
|
}
|
|
|
|
static int cfset_all_copy(unsigned long arg, cpumask_t *mask)
|
|
{
|
|
struct s390_ctrset_read __user *ctrset_read;
|
|
unsigned int cpu, cpus, rc;
|
|
void __user *uptr;
|
|
|
|
ctrset_read = (struct s390_ctrset_read __user *)arg;
|
|
uptr = ctrset_read->data;
|
|
for_each_cpu(cpu, mask) {
|
|
struct cpu_cf_events *cpuhw = per_cpu_ptr(&cpu_cf_events, cpu);
|
|
struct s390_ctrset_cpudata __user *ctrset_cpudata;
|
|
|
|
ctrset_cpudata = uptr;
|
|
rc = put_user(cpu, &ctrset_cpudata->cpu_nr);
|
|
rc |= put_user(cpuhw->sets, &ctrset_cpudata->no_sets);
|
|
rc |= copy_to_user(ctrset_cpudata->data, cpuhw->data,
|
|
cpuhw->used);
|
|
if (rc)
|
|
return -EFAULT;
|
|
uptr += sizeof(struct s390_ctrset_cpudata) + cpuhw->used;
|
|
cond_resched();
|
|
}
|
|
cpus = cpumask_weight(mask);
|
|
if (put_user(cpus, &ctrset_read->no_cpus))
|
|
return -EFAULT;
|
|
debug_sprintf_event(cf_dbg, 4, "%s copied %ld\n", __func__,
|
|
uptr - (void __user *)ctrset_read->data);
|
|
return 0;
|
|
}
|
|
|
|
static size_t cfset_cpuset_read(struct s390_ctrset_setdata *p, int ctrset,
|
|
int ctrset_size, size_t room)
|
|
{
|
|
size_t need = 0;
|
|
int rc = -1;
|
|
|
|
need = sizeof(*p) + sizeof(u64) * ctrset_size;
|
|
if (need <= room) {
|
|
p->set = cpumf_ctr_ctl[ctrset];
|
|
p->no_cnts = ctrset_size;
|
|
rc = ctr_stcctm(ctrset, ctrset_size, (u64 *)p->cv);
|
|
if (rc == 3) /* Nothing stored */
|
|
need = 0;
|
|
}
|
|
return need;
|
|
}
|
|
|
|
/* Read all counter sets. */
|
|
static void cfset_cpu_read(void *parm)
|
|
{
|
|
struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
|
|
struct cfset_call_on_cpu_parm *p = parm;
|
|
int set, set_size;
|
|
size_t space;
|
|
|
|
/* No data saved yet */
|
|
cpuhw->used = 0;
|
|
cpuhw->sets = 0;
|
|
memset(cpuhw->data, 0, sizeof(cpuhw->data));
|
|
|
|
/* Scan the counter sets */
|
|
for (set = CPUMF_CTR_SET_BASIC; set < CPUMF_CTR_SET_MAX; ++set) {
|
|
struct s390_ctrset_setdata *sp = (void *)cpuhw->data +
|
|
cpuhw->used;
|
|
|
|
if (!(p->sets & cpumf_ctr_ctl[set]))
|
|
continue; /* Counter set not in list */
|
|
set_size = cpum_cf_ctrset_size(set, &cpuhw->info);
|
|
space = sizeof(cpuhw->data) - cpuhw->used;
|
|
space = cfset_cpuset_read(sp, set, set_size, space);
|
|
if (space) {
|
|
cpuhw->used += space;
|
|
cpuhw->sets += 1;
|
|
}
|
|
}
|
|
debug_sprintf_event(cf_dbg, 4, "%s sets %d used %zd\n", __func__,
|
|
cpuhw->sets, cpuhw->used);
|
|
}
|
|
|
|
static int cfset_all_read(unsigned long arg, struct cfset_request *req)
|
|
{
|
|
struct cfset_call_on_cpu_parm p;
|
|
cpumask_var_t mask;
|
|
int rc;
|
|
|
|
if (!alloc_cpumask_var(&mask, GFP_KERNEL))
|
|
return -ENOMEM;
|
|
|
|
p.sets = req->ctrset;
|
|
cpumask_and(mask, &req->mask, cpu_online_mask);
|
|
on_each_cpu_mask(mask, cfset_cpu_read, &p, 1);
|
|
rc = cfset_all_copy(arg, mask);
|
|
free_cpumask_var(mask);
|
|
return rc;
|
|
}
|
|
|
|
static long cfset_ioctl_read(unsigned long arg, struct cfset_request *req)
|
|
{
|
|
struct s390_ctrset_read read;
|
|
int ret = -ENODATA;
|
|
|
|
if (req && req->ctrset) {
|
|
if (copy_from_user(&read, (char __user *)arg, sizeof(read)))
|
|
return -EFAULT;
|
|
ret = cfset_all_read(arg, req);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static long cfset_ioctl_stop(struct file *file)
|
|
{
|
|
struct cfset_request *req = file->private_data;
|
|
int ret = -ENXIO;
|
|
|
|
if (req) {
|
|
cfset_all_stop(req);
|
|
cfset_session_del(req);
|
|
kfree(req);
|
|
file->private_data = NULL;
|
|
ret = 0;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static long cfset_ioctl_start(unsigned long arg, struct file *file)
|
|
{
|
|
struct s390_ctrset_start __user *ustart;
|
|
struct s390_ctrset_start start;
|
|
struct cfset_request *preq;
|
|
void __user *umask;
|
|
unsigned int len;
|
|
int ret = 0;
|
|
size_t need;
|
|
|
|
if (file->private_data)
|
|
return -EBUSY;
|
|
ustart = (struct s390_ctrset_start __user *)arg;
|
|
if (copy_from_user(&start, ustart, sizeof(start)))
|
|
return -EFAULT;
|
|
if (start.version != S390_HWCTR_START_VERSION)
|
|
return -EINVAL;
|
|
if (start.counter_sets & ~(cpumf_ctr_ctl[CPUMF_CTR_SET_BASIC] |
|
|
cpumf_ctr_ctl[CPUMF_CTR_SET_USER] |
|
|
cpumf_ctr_ctl[CPUMF_CTR_SET_CRYPTO] |
|
|
cpumf_ctr_ctl[CPUMF_CTR_SET_EXT] |
|
|
cpumf_ctr_ctl[CPUMF_CTR_SET_MT_DIAG]))
|
|
return -EINVAL; /* Invalid counter set */
|
|
if (!start.counter_sets)
|
|
return -EINVAL; /* No counter set at all? */
|
|
|
|
preq = kzalloc(sizeof(*preq), GFP_KERNEL);
|
|
if (!preq)
|
|
return -ENOMEM;
|
|
cpumask_clear(&preq->mask);
|
|
len = min_t(u64, start.cpumask_len, cpumask_size());
|
|
umask = (void __user *)start.cpumask;
|
|
if (copy_from_user(&preq->mask, umask, len)) {
|
|
kfree(preq);
|
|
return -EFAULT;
|
|
}
|
|
if (cpumask_empty(&preq->mask)) {
|
|
kfree(preq);
|
|
return -EINVAL;
|
|
}
|
|
need = cfset_needspace(start.counter_sets);
|
|
if (put_user(need, &ustart->data_bytes)) {
|
|
kfree(preq);
|
|
return -EFAULT;
|
|
}
|
|
preq->ctrset = start.counter_sets;
|
|
ret = cfset_all_start(preq);
|
|
if (!ret) {
|
|
cfset_session_add(preq);
|
|
file->private_data = preq;
|
|
debug_sprintf_event(cf_dbg, 4, "%s set %#lx need %ld ret %d\n",
|
|
__func__, preq->ctrset, need, ret);
|
|
} else {
|
|
kfree(preq);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/* Entry point to the /dev/hwctr device interface.
|
|
* The ioctl system call supports three subcommands:
|
|
* S390_HWCTR_START: Start the specified counter sets on a CPU list. The
|
|
* counter set keeps running until explicitly stopped. Returns the number
|
|
* of bytes needed to store the counter values. If another S390_HWCTR_START
|
|
* ioctl subcommand is called without a previous S390_HWCTR_STOP stop
|
|
* command on the same file descriptor, -EBUSY is returned.
|
|
* S390_HWCTR_READ: Read the counter set values from specified CPU list given
|
|
* with the S390_HWCTR_START command.
|
|
* S390_HWCTR_STOP: Stops the counter sets on the CPU list given with the
|
|
* previous S390_HWCTR_START subcommand.
|
|
*/
|
|
static long cfset_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|
{
|
|
int ret;
|
|
|
|
cpus_read_lock();
|
|
mutex_lock(&cfset_ctrset_mutex);
|
|
switch (cmd) {
|
|
case S390_HWCTR_START:
|
|
ret = cfset_ioctl_start(arg, file);
|
|
break;
|
|
case S390_HWCTR_STOP:
|
|
ret = cfset_ioctl_stop(file);
|
|
break;
|
|
case S390_HWCTR_READ:
|
|
ret = cfset_ioctl_read(arg, file->private_data);
|
|
break;
|
|
default:
|
|
ret = -ENOTTY;
|
|
break;
|
|
}
|
|
mutex_unlock(&cfset_ctrset_mutex);
|
|
cpus_read_unlock();
|
|
return ret;
|
|
}
|
|
|
|
static const struct file_operations cfset_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = cfset_open,
|
|
.release = cfset_release,
|
|
.unlocked_ioctl = cfset_ioctl,
|
|
.compat_ioctl = cfset_ioctl,
|
|
.llseek = no_llseek
|
|
};
|
|
|
|
static struct miscdevice cfset_dev = {
|
|
.name = S390_HWCTR_DEVICE,
|
|
.minor = MISC_DYNAMIC_MINOR,
|
|
.fops = &cfset_fops,
|
|
};
|
|
|
|
/* Hotplug add of a CPU. Scan through all active processes and add
|
|
* that CPU to the list of CPUs supplied with ioctl(..., START, ...).
|
|
*/
|
|
int cfset_online_cpu(unsigned int cpu)
|
|
{
|
|
struct cfset_call_on_cpu_parm p;
|
|
struct cfset_request *rp;
|
|
|
|
mutex_lock(&cfset_ctrset_mutex);
|
|
if (!list_empty(&cfset_session.head)) {
|
|
list_for_each_entry(rp, &cfset_session.head, node) {
|
|
p.sets = rp->ctrset;
|
|
cfset_ioctl_on(&p);
|
|
cpumask_set_cpu(cpu, &rp->mask);
|
|
}
|
|
}
|
|
mutex_unlock(&cfset_ctrset_mutex);
|
|
return 0;
|
|
}
|
|
|
|
/* Hotplug remove of a CPU. Scan through all active processes and clear
|
|
* that CPU from the list of CPUs supplied with ioctl(..., START, ...).
|
|
*/
|
|
int cfset_offline_cpu(unsigned int cpu)
|
|
{
|
|
struct cfset_call_on_cpu_parm p;
|
|
struct cfset_request *rp;
|
|
|
|
mutex_lock(&cfset_ctrset_mutex);
|
|
if (!list_empty(&cfset_session.head)) {
|
|
list_for_each_entry(rp, &cfset_session.head, node) {
|
|
p.sets = rp->ctrset;
|
|
cfset_ioctl_off(&p);
|
|
cpumask_clear_cpu(cpu, &rp->mask);
|
|
}
|
|
}
|
|
mutex_unlock(&cfset_ctrset_mutex);
|
|
return 0;
|
|
}
|
|
|
|
static void cfdiag_read(struct perf_event *event)
|
|
{
|
|
debug_sprintf_event(cf_dbg, 3, "%s event %#llx count %ld\n", __func__,
|
|
event->attr.config, local64_read(&event->count));
|
|
}
|
|
|
|
static int get_authctrsets(void)
|
|
{
|
|
struct cpu_cf_events *cpuhw;
|
|
unsigned long auth = 0;
|
|
enum cpumf_ctr_set i;
|
|
|
|
cpuhw = &get_cpu_var(cpu_cf_events);
|
|
for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
|
|
if (cpuhw->info.auth_ctl & cpumf_ctr_ctl[i])
|
|
auth |= cpumf_ctr_ctl[i];
|
|
}
|
|
put_cpu_var(cpu_cf_events);
|
|
return auth;
|
|
}
|
|
|
|
/* Setup the event. Test for authorized counter sets and only include counter
|
|
* sets which are authorized at the time of the setup. Including unauthorized
|
|
* counter sets result in specification exception (and panic).
|
|
*/
|
|
static int cfdiag_event_init2(struct perf_event *event)
|
|
{
|
|
struct perf_event_attr *attr = &event->attr;
|
|
int err = 0;
|
|
|
|
/* Set sample_period to indicate sampling */
|
|
event->hw.config = attr->config;
|
|
event->hw.sample_period = attr->sample_period;
|
|
local64_set(&event->hw.period_left, event->hw.sample_period);
|
|
local64_set(&event->count, 0);
|
|
event->hw.last_period = event->hw.sample_period;
|
|
|
|
/* Add all authorized counter sets to config_base. The
|
|
* the hardware init function is either called per-cpu or just once
|
|
* for all CPUS (event->cpu == -1). This depends on the whether
|
|
* counting is started for all CPUs or on a per workload base where
|
|
* the perf event moves from one CPU to another CPU.
|
|
* Checking the authorization on any CPU is fine as the hardware
|
|
* applies the same authorization settings to all CPUs.
|
|
*/
|
|
event->hw.config_base = get_authctrsets();
|
|
|
|
/* No authorized counter sets, nothing to count/sample */
|
|
if (!event->hw.config_base)
|
|
err = -EINVAL;
|
|
|
|
debug_sprintf_event(cf_dbg, 5, "%s err %d config_base %#lx\n",
|
|
__func__, err, event->hw.config_base);
|
|
return err;
|
|
}
|
|
|
|
static int cfdiag_event_init(struct perf_event *event)
|
|
{
|
|
struct perf_event_attr *attr = &event->attr;
|
|
int err = -ENOENT;
|
|
|
|
if (event->attr.config != PERF_EVENT_CPUM_CF_DIAG ||
|
|
event->attr.type != event->pmu->type)
|
|
goto out;
|
|
|
|
/* Raw events are used to access counters directly,
|
|
* hence do not permit excludes.
|
|
* This event is useless without PERF_SAMPLE_RAW to return counter set
|
|
* values as raw data.
|
|
*/
|
|
if (attr->exclude_kernel || attr->exclude_user || attr->exclude_hv ||
|
|
!(attr->sample_type & (PERF_SAMPLE_CPU | PERF_SAMPLE_RAW))) {
|
|
err = -EOPNOTSUPP;
|
|
goto out;
|
|
}
|
|
|
|
/* Initialize for using the CPU-measurement counter facility */
|
|
cpumf_hw_inuse();
|
|
event->destroy = hw_perf_event_destroy;
|
|
|
|
err = cfdiag_event_init2(event);
|
|
if (unlikely(err))
|
|
event->destroy(event);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
/* Create cf_diag/events/CF_DIAG event sysfs file. This counter is used
|
|
* to collect the complete counter sets for a scheduled process. Target
|
|
* are complete counter sets attached as raw data to the artificial event.
|
|
* This results in complete counter sets available when a process is
|
|
* scheduled. Contains the delta of every counter while the process was
|
|
* running.
|
|
*/
|
|
CPUMF_EVENT_ATTR(CF_DIAG, CF_DIAG, PERF_EVENT_CPUM_CF_DIAG);
|
|
|
|
static struct attribute *cfdiag_events_attr[] = {
|
|
CPUMF_EVENT_PTR(CF_DIAG, CF_DIAG),
|
|
NULL,
|
|
};
|
|
|
|
PMU_FORMAT_ATTR(event, "config:0-63");
|
|
|
|
static struct attribute *cfdiag_format_attr[] = {
|
|
&format_attr_event.attr,
|
|
NULL,
|
|
};
|
|
|
|
static struct attribute_group cfdiag_events_group = {
|
|
.name = "events",
|
|
.attrs = cfdiag_events_attr,
|
|
};
|
|
static struct attribute_group cfdiag_format_group = {
|
|
.name = "format",
|
|
.attrs = cfdiag_format_attr,
|
|
};
|
|
static const struct attribute_group *cfdiag_attr_groups[] = {
|
|
&cfdiag_events_group,
|
|
&cfdiag_format_group,
|
|
NULL,
|
|
};
|
|
|
|
/* Performance monitoring unit for event CF_DIAG. Since this event
|
|
* is also started and stopped via the perf_event_open() system call, use
|
|
* the same event enable/disable call back functions. They do not
|
|
* have a pointer to the perf_event strcture as first parameter.
|
|
*
|
|
* The functions XXX_add, XXX_del, XXX_start and XXX_stop are also common.
|
|
* Reuse them and distinguish the event (always first parameter) via
|
|
* 'config' member.
|
|
*/
|
|
static struct pmu cf_diag = {
|
|
.task_ctx_nr = perf_sw_context,
|
|
.event_init = cfdiag_event_init,
|
|
.pmu_enable = cpumf_pmu_enable,
|
|
.pmu_disable = cpumf_pmu_disable,
|
|
.add = cpumf_pmu_add,
|
|
.del = cpumf_pmu_del,
|
|
.start = cpumf_pmu_start,
|
|
.stop = cpumf_pmu_stop,
|
|
.read = cfdiag_read,
|
|
|
|
.attr_groups = cfdiag_attr_groups
|
|
};
|
|
|
|
/* Calculate memory needed to store all counter sets together with header and
|
|
* trailer data. This is independent of the counter set authorization which
|
|
* can vary depending on the configuration.
|
|
*/
|
|
static size_t cfdiag_maxsize(struct cpumf_ctr_info *info)
|
|
{
|
|
size_t max_size = sizeof(struct cf_trailer_entry);
|
|
enum cpumf_ctr_set i;
|
|
|
|
for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
|
|
size_t size = cpum_cf_ctrset_size(i, info);
|
|
|
|
if (size)
|
|
max_size += size * sizeof(u64) +
|
|
sizeof(struct cf_ctrset_entry);
|
|
}
|
|
return max_size;
|
|
}
|
|
|
|
/* Get the CPU speed, try sampling facility first and CPU attributes second. */
|
|
static void cfdiag_get_cpu_speed(void)
|
|
{
|
|
if (cpum_sf_avail()) { /* Sampling facility first */
|
|
struct hws_qsi_info_block si;
|
|
|
|
memset(&si, 0, sizeof(si));
|
|
if (!qsi(&si)) {
|
|
cfdiag_cpu_speed = si.cpu_speed;
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* Fallback: CPU speed extract static part. Used in case
|
|
* CPU Measurement Sampling Facility is turned off.
|
|
*/
|
|
if (test_facility(34)) {
|
|
unsigned long mhz = __ecag(ECAG_CPU_ATTRIBUTE, 0);
|
|
|
|
if (mhz != -1UL)
|
|
cfdiag_cpu_speed = mhz & 0xffffffff;
|
|
}
|
|
}
|
|
|
|
static int cfset_init(void)
|
|
{
|
|
struct cpumf_ctr_info info;
|
|
size_t need;
|
|
int rc;
|
|
|
|
if (qctri(&info))
|
|
return -ENODEV;
|
|
|
|
cfdiag_get_cpu_speed();
|
|
/* Make sure the counter set data fits into predefined buffer. */
|
|
need = cfdiag_maxsize(&info);
|
|
if (need > sizeof(((struct cpu_cf_events *)0)->start)) {
|
|
pr_err("Insufficient memory for PMU(cpum_cf_diag) need=%zu\n",
|
|
need);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
rc = misc_register(&cfset_dev);
|
|
if (rc) {
|
|
pr_err("Registration of /dev/%s failed rc=%i\n",
|
|
cfset_dev.name, rc);
|
|
goto out;
|
|
}
|
|
|
|
rc = perf_pmu_register(&cf_diag, "cpum_cf_diag", -1);
|
|
if (rc) {
|
|
misc_deregister(&cfset_dev);
|
|
pr_err("Registration of PMU(cpum_cf_diag) failed with rc=%i\n",
|
|
rc);
|
|
}
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
device_initcall(cpumf_pmu_init);
|