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df4d29732f
It turns out that the NMI latency workaround from commit:6d3edaae16
("x86/perf/amd: Resolve NMI latency issues for active PMCs") ends up being too conservative and results in the perf NMI handler claiming NMIs too easily on AMD hardware when the NMI watchdog is active. This has an impact, for example, on the hpwdt (HPE watchdog timer) module. This module can produce an NMI that is used to reset the system. It registers an NMI handler for the NMI_UNKNOWN type and relies on the fact that nothing has claimed an NMI so that its handler will be invoked when the watchdog device produces an NMI. After the referenced commit, the hpwdt module is unable to process its generated NMI if the NMI watchdog is active, because the current NMI latency mitigation results in the NMI being claimed by the perf NMI handler. Update the AMD perf NMI latency mitigation workaround to, instead, use a window of time. Whenever a PMC is handled in the perf NMI handler, set a timestamp which will act as a perf NMI window. Any NMIs arriving within that window will be claimed by perf. Anything outside that window will not be claimed by perf. The value for the NMI window is set to 100 msecs. This is a conservative value that easily covers any NMI latency in the hardware. While this still results in a window in which the hpwdt module will not receive its NMI, the window is now much, much smaller. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jerry Hoemann <jerry.hoemann@hpe.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes:6d3edaae16
("x86/perf/amd: Resolve NMI latency issues for active PMCs") Link: https://lkml.kernel.org/r/Message-ID: Signed-off-by: Ingo Molnar <mingo@kernel.org>
1014 lines
26 KiB
C
1014 lines
26 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/perf_event.h>
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#include <linux/export.h>
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#include <linux/types.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/delay.h>
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#include <linux/jiffies.h>
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#include <asm/apicdef.h>
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#include <asm/nmi.h>
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#include "../perf_event.h"
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static DEFINE_PER_CPU(unsigned long, perf_nmi_tstamp);
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static unsigned long perf_nmi_window;
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static __initconst const u64 amd_hw_cache_event_ids
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[PERF_COUNT_HW_CACHE_MAX]
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[PERF_COUNT_HW_CACHE_OP_MAX]
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[PERF_COUNT_HW_CACHE_RESULT_MAX] =
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{
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[ C(L1D) ] = {
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[ C(OP_READ) ] = {
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[ C(RESULT_ACCESS) ] = 0x0040, /* Data Cache Accesses */
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[ C(RESULT_MISS) ] = 0x0141, /* Data Cache Misses */
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},
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[ C(OP_WRITE) ] = {
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[ C(RESULT_ACCESS) ] = 0,
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[ C(RESULT_MISS) ] = 0,
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},
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[ C(OP_PREFETCH) ] = {
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[ C(RESULT_ACCESS) ] = 0x0267, /* Data Prefetcher :attempts */
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[ C(RESULT_MISS) ] = 0x0167, /* Data Prefetcher :cancelled */
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},
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},
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[ C(L1I ) ] = {
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[ C(OP_READ) ] = {
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[ C(RESULT_ACCESS) ] = 0x0080, /* Instruction cache fetches */
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[ C(RESULT_MISS) ] = 0x0081, /* Instruction cache misses */
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},
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[ C(OP_WRITE) ] = {
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[ C(RESULT_ACCESS) ] = -1,
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[ C(RESULT_MISS) ] = -1,
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},
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[ C(OP_PREFETCH) ] = {
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[ C(RESULT_ACCESS) ] = 0x014B, /* Prefetch Instructions :Load */
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[ C(RESULT_MISS) ] = 0,
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},
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},
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[ C(LL ) ] = {
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[ C(OP_READ) ] = {
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[ C(RESULT_ACCESS) ] = 0x037D, /* Requests to L2 Cache :IC+DC */
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[ C(RESULT_MISS) ] = 0x037E, /* L2 Cache Misses : IC+DC */
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},
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[ C(OP_WRITE) ] = {
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[ C(RESULT_ACCESS) ] = 0x017F, /* L2 Fill/Writeback */
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[ C(RESULT_MISS) ] = 0,
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},
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[ C(OP_PREFETCH) ] = {
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[ C(RESULT_ACCESS) ] = 0,
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[ C(RESULT_MISS) ] = 0,
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},
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},
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[ C(DTLB) ] = {
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[ C(OP_READ) ] = {
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[ C(RESULT_ACCESS) ] = 0x0040, /* Data Cache Accesses */
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[ C(RESULT_MISS) ] = 0x0746, /* L1_DTLB_AND_L2_DLTB_MISS.ALL */
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},
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[ C(OP_WRITE) ] = {
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[ C(RESULT_ACCESS) ] = 0,
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[ C(RESULT_MISS) ] = 0,
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},
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[ C(OP_PREFETCH) ] = {
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[ C(RESULT_ACCESS) ] = 0,
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[ C(RESULT_MISS) ] = 0,
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},
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},
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[ C(ITLB) ] = {
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[ C(OP_READ) ] = {
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[ C(RESULT_ACCESS) ] = 0x0080, /* Instruction fecthes */
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[ C(RESULT_MISS) ] = 0x0385, /* L1_ITLB_AND_L2_ITLB_MISS.ALL */
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},
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[ C(OP_WRITE) ] = {
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[ C(RESULT_ACCESS) ] = -1,
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[ C(RESULT_MISS) ] = -1,
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},
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[ C(OP_PREFETCH) ] = {
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[ C(RESULT_ACCESS) ] = -1,
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[ C(RESULT_MISS) ] = -1,
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},
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},
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[ C(BPU ) ] = {
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[ C(OP_READ) ] = {
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[ C(RESULT_ACCESS) ] = 0x00c2, /* Retired Branch Instr. */
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[ C(RESULT_MISS) ] = 0x00c3, /* Retired Mispredicted BI */
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},
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[ C(OP_WRITE) ] = {
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[ C(RESULT_ACCESS) ] = -1,
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[ C(RESULT_MISS) ] = -1,
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},
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[ C(OP_PREFETCH) ] = {
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[ C(RESULT_ACCESS) ] = -1,
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[ C(RESULT_MISS) ] = -1,
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},
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},
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[ C(NODE) ] = {
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[ C(OP_READ) ] = {
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[ C(RESULT_ACCESS) ] = 0xb8e9, /* CPU Request to Memory, l+r */
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[ C(RESULT_MISS) ] = 0x98e9, /* CPU Request to Memory, r */
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},
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[ C(OP_WRITE) ] = {
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[ C(RESULT_ACCESS) ] = -1,
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[ C(RESULT_MISS) ] = -1,
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},
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[ C(OP_PREFETCH) ] = {
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[ C(RESULT_ACCESS) ] = -1,
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[ C(RESULT_MISS) ] = -1,
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},
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},
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};
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static __initconst const u64 amd_hw_cache_event_ids_f17h
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[PERF_COUNT_HW_CACHE_MAX]
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[PERF_COUNT_HW_CACHE_OP_MAX]
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[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
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[C(L1D)] = {
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[C(OP_READ)] = {
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[C(RESULT_ACCESS)] = 0x0040, /* Data Cache Accesses */
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[C(RESULT_MISS)] = 0xc860, /* L2$ access from DC Miss */
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},
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[C(OP_WRITE)] = {
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[C(RESULT_ACCESS)] = 0,
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[C(RESULT_MISS)] = 0,
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},
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[C(OP_PREFETCH)] = {
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[C(RESULT_ACCESS)] = 0xff5a, /* h/w prefetch DC Fills */
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[C(RESULT_MISS)] = 0,
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},
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},
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[C(L1I)] = {
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[C(OP_READ)] = {
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[C(RESULT_ACCESS)] = 0x0080, /* Instruction cache fetches */
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[C(RESULT_MISS)] = 0x0081, /* Instruction cache misses */
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},
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[C(OP_WRITE)] = {
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[C(RESULT_ACCESS)] = -1,
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[C(RESULT_MISS)] = -1,
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},
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[C(OP_PREFETCH)] = {
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[C(RESULT_ACCESS)] = 0,
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[C(RESULT_MISS)] = 0,
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},
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},
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[C(LL)] = {
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[C(OP_READ)] = {
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[C(RESULT_ACCESS)] = 0,
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[C(RESULT_MISS)] = 0,
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},
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[C(OP_WRITE)] = {
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[C(RESULT_ACCESS)] = 0,
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[C(RESULT_MISS)] = 0,
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},
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[C(OP_PREFETCH)] = {
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[C(RESULT_ACCESS)] = 0,
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[C(RESULT_MISS)] = 0,
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},
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},
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[C(DTLB)] = {
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[C(OP_READ)] = {
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[C(RESULT_ACCESS)] = 0xff45, /* All L2 DTLB accesses */
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[C(RESULT_MISS)] = 0xf045, /* L2 DTLB misses (PT walks) */
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},
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[C(OP_WRITE)] = {
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[C(RESULT_ACCESS)] = 0,
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[C(RESULT_MISS)] = 0,
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},
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[C(OP_PREFETCH)] = {
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[C(RESULT_ACCESS)] = 0,
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[C(RESULT_MISS)] = 0,
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},
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},
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[C(ITLB)] = {
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[C(OP_READ)] = {
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[C(RESULT_ACCESS)] = 0x0084, /* L1 ITLB misses, L2 ITLB hits */
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[C(RESULT_MISS)] = 0xff85, /* L1 ITLB misses, L2 misses */
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},
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[C(OP_WRITE)] = {
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[C(RESULT_ACCESS)] = -1,
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[C(RESULT_MISS)] = -1,
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},
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[C(OP_PREFETCH)] = {
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[C(RESULT_ACCESS)] = -1,
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[C(RESULT_MISS)] = -1,
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},
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},
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[C(BPU)] = {
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[C(OP_READ)] = {
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[C(RESULT_ACCESS)] = 0x00c2, /* Retired Branch Instr. */
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[C(RESULT_MISS)] = 0x00c3, /* Retired Mispredicted BI */
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},
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[C(OP_WRITE)] = {
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[C(RESULT_ACCESS)] = -1,
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[C(RESULT_MISS)] = -1,
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},
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[C(OP_PREFETCH)] = {
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[C(RESULT_ACCESS)] = -1,
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[C(RESULT_MISS)] = -1,
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},
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},
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[C(NODE)] = {
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[C(OP_READ)] = {
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[C(RESULT_ACCESS)] = 0,
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[C(RESULT_MISS)] = 0,
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},
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[C(OP_WRITE)] = {
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[C(RESULT_ACCESS)] = -1,
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[C(RESULT_MISS)] = -1,
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},
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[C(OP_PREFETCH)] = {
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[C(RESULT_ACCESS)] = -1,
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[C(RESULT_MISS)] = -1,
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},
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},
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};
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/*
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* AMD Performance Monitor K7 and later, up to and including Family 16h:
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*/
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static const u64 amd_perfmon_event_map[PERF_COUNT_HW_MAX] =
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{
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[PERF_COUNT_HW_CPU_CYCLES] = 0x0076,
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[PERF_COUNT_HW_INSTRUCTIONS] = 0x00c0,
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[PERF_COUNT_HW_CACHE_REFERENCES] = 0x077d,
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[PERF_COUNT_HW_CACHE_MISSES] = 0x077e,
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[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = 0x00c2,
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[PERF_COUNT_HW_BRANCH_MISSES] = 0x00c3,
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[PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = 0x00d0, /* "Decoder empty" event */
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[PERF_COUNT_HW_STALLED_CYCLES_BACKEND] = 0x00d1, /* "Dispatch stalls" event */
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};
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/*
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* AMD Performance Monitor Family 17h and later:
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*/
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static const u64 amd_f17h_perfmon_event_map[PERF_COUNT_HW_MAX] =
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{
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[PERF_COUNT_HW_CPU_CYCLES] = 0x0076,
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[PERF_COUNT_HW_INSTRUCTIONS] = 0x00c0,
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[PERF_COUNT_HW_CACHE_REFERENCES] = 0xff60,
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[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = 0x00c2,
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[PERF_COUNT_HW_BRANCH_MISSES] = 0x00c3,
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[PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = 0x0287,
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[PERF_COUNT_HW_STALLED_CYCLES_BACKEND] = 0x0187,
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};
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static u64 amd_pmu_event_map(int hw_event)
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{
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if (boot_cpu_data.x86 >= 0x17)
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return amd_f17h_perfmon_event_map[hw_event];
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return amd_perfmon_event_map[hw_event];
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}
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/*
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* Previously calculated offsets
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*/
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static unsigned int event_offsets[X86_PMC_IDX_MAX] __read_mostly;
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static unsigned int count_offsets[X86_PMC_IDX_MAX] __read_mostly;
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/*
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* Legacy CPUs:
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* 4 counters starting at 0xc0010000 each offset by 1
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*
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* CPUs with core performance counter extensions:
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* 6 counters starting at 0xc0010200 each offset by 2
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*/
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static inline int amd_pmu_addr_offset(int index, bool eventsel)
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{
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int offset;
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if (!index)
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return index;
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if (eventsel)
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offset = event_offsets[index];
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else
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offset = count_offsets[index];
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if (offset)
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return offset;
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if (!boot_cpu_has(X86_FEATURE_PERFCTR_CORE))
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offset = index;
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else
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offset = index << 1;
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if (eventsel)
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event_offsets[index] = offset;
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else
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count_offsets[index] = offset;
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return offset;
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}
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static int amd_core_hw_config(struct perf_event *event)
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{
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if (event->attr.exclude_host && event->attr.exclude_guest)
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/*
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* When HO == GO == 1 the hardware treats that as GO == HO == 0
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* and will count in both modes. We don't want to count in that
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* case so we emulate no-counting by setting US = OS = 0.
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*/
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event->hw.config &= ~(ARCH_PERFMON_EVENTSEL_USR |
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ARCH_PERFMON_EVENTSEL_OS);
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else if (event->attr.exclude_host)
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event->hw.config |= AMD64_EVENTSEL_GUESTONLY;
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else if (event->attr.exclude_guest)
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event->hw.config |= AMD64_EVENTSEL_HOSTONLY;
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return 0;
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}
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/*
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* AMD64 events are detected based on their event codes.
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*/
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static inline unsigned int amd_get_event_code(struct hw_perf_event *hwc)
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{
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return ((hwc->config >> 24) & 0x0f00) | (hwc->config & 0x00ff);
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}
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static inline int amd_is_nb_event(struct hw_perf_event *hwc)
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{
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return (hwc->config & 0xe0) == 0xe0;
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}
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static inline int amd_has_nb(struct cpu_hw_events *cpuc)
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{
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struct amd_nb *nb = cpuc->amd_nb;
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return nb && nb->nb_id != -1;
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}
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static int amd_pmu_hw_config(struct perf_event *event)
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{
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int ret;
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/* pass precise event sampling to ibs: */
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if (event->attr.precise_ip && get_ibs_caps())
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return -ENOENT;
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if (has_branch_stack(event))
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return -EOPNOTSUPP;
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ret = x86_pmu_hw_config(event);
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if (ret)
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return ret;
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if (event->attr.type == PERF_TYPE_RAW)
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event->hw.config |= event->attr.config & AMD64_RAW_EVENT_MASK;
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return amd_core_hw_config(event);
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}
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static void __amd_put_nb_event_constraints(struct cpu_hw_events *cpuc,
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struct perf_event *event)
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{
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struct amd_nb *nb = cpuc->amd_nb;
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int i;
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/*
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* need to scan whole list because event may not have
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* been assigned during scheduling
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*
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* no race condition possible because event can only
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* be removed on one CPU at a time AND PMU is disabled
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* when we come here
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*/
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for (i = 0; i < x86_pmu.num_counters; i++) {
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if (cmpxchg(nb->owners + i, event, NULL) == event)
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break;
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}
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}
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/*
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* AMD64 NorthBridge events need special treatment because
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* counter access needs to be synchronized across all cores
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* of a package. Refer to BKDG section 3.12
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*
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* NB events are events measuring L3 cache, Hypertransport
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* traffic. They are identified by an event code >= 0xe00.
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* They measure events on the NorthBride which is shared
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* by all cores on a package. NB events are counted on a
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* shared set of counters. When a NB event is programmed
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* in a counter, the data actually comes from a shared
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* counter. Thus, access to those counters needs to be
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* synchronized.
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*
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* We implement the synchronization such that no two cores
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* can be measuring NB events using the same counters. Thus,
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* we maintain a per-NB allocation table. The available slot
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* is propagated using the event_constraint structure.
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*
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* We provide only one choice for each NB event based on
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* the fact that only NB events have restrictions. Consequently,
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* if a counter is available, there is a guarantee the NB event
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* will be assigned to it. If no slot is available, an empty
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* constraint is returned and scheduling will eventually fail
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* for this event.
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*
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* Note that all cores attached the same NB compete for the same
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* counters to host NB events, this is why we use atomic ops. Some
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* multi-chip CPUs may have more than one NB.
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*
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* Given that resources are allocated (cmpxchg), they must be
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* eventually freed for others to use. This is accomplished by
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* calling __amd_put_nb_event_constraints()
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*
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* Non NB events are not impacted by this restriction.
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*/
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static struct event_constraint *
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__amd_get_nb_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event,
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struct event_constraint *c)
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{
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struct hw_perf_event *hwc = &event->hw;
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struct amd_nb *nb = cpuc->amd_nb;
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struct perf_event *old;
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int idx, new = -1;
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if (!c)
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c = &unconstrained;
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if (cpuc->is_fake)
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return c;
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/*
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* detect if already present, if so reuse
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*
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* cannot merge with actual allocation
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* because of possible holes
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*
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* event can already be present yet not assigned (in hwc->idx)
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* because of successive calls to x86_schedule_events() from
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* hw_perf_group_sched_in() without hw_perf_enable()
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*/
|
|
for_each_set_bit(idx, c->idxmsk, x86_pmu.num_counters) {
|
|
if (new == -1 || hwc->idx == idx)
|
|
/* assign free slot, prefer hwc->idx */
|
|
old = cmpxchg(nb->owners + idx, NULL, event);
|
|
else if (nb->owners[idx] == event)
|
|
/* event already present */
|
|
old = event;
|
|
else
|
|
continue;
|
|
|
|
if (old && old != event)
|
|
continue;
|
|
|
|
/* reassign to this slot */
|
|
if (new != -1)
|
|
cmpxchg(nb->owners + new, event, NULL);
|
|
new = idx;
|
|
|
|
/* already present, reuse */
|
|
if (old == event)
|
|
break;
|
|
}
|
|
|
|
if (new == -1)
|
|
return &emptyconstraint;
|
|
|
|
return &nb->event_constraints[new];
|
|
}
|
|
|
|
static struct amd_nb *amd_alloc_nb(int cpu)
|
|
{
|
|
struct amd_nb *nb;
|
|
int i;
|
|
|
|
nb = kzalloc_node(sizeof(struct amd_nb), GFP_KERNEL, cpu_to_node(cpu));
|
|
if (!nb)
|
|
return NULL;
|
|
|
|
nb->nb_id = -1;
|
|
|
|
/*
|
|
* initialize all possible NB constraints
|
|
*/
|
|
for (i = 0; i < x86_pmu.num_counters; i++) {
|
|
__set_bit(i, nb->event_constraints[i].idxmsk);
|
|
nb->event_constraints[i].weight = 1;
|
|
}
|
|
return nb;
|
|
}
|
|
|
|
static int amd_pmu_cpu_prepare(int cpu)
|
|
{
|
|
struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
|
|
|
|
WARN_ON_ONCE(cpuc->amd_nb);
|
|
|
|
if (!x86_pmu.amd_nb_constraints)
|
|
return 0;
|
|
|
|
cpuc->amd_nb = amd_alloc_nb(cpu);
|
|
if (!cpuc->amd_nb)
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void amd_pmu_cpu_starting(int cpu)
|
|
{
|
|
struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
|
|
void **onln = &cpuc->kfree_on_online[X86_PERF_KFREE_SHARED];
|
|
struct amd_nb *nb;
|
|
int i, nb_id;
|
|
|
|
cpuc->perf_ctr_virt_mask = AMD64_EVENTSEL_HOSTONLY;
|
|
|
|
if (!x86_pmu.amd_nb_constraints)
|
|
return;
|
|
|
|
nb_id = amd_get_nb_id(cpu);
|
|
WARN_ON_ONCE(nb_id == BAD_APICID);
|
|
|
|
for_each_online_cpu(i) {
|
|
nb = per_cpu(cpu_hw_events, i).amd_nb;
|
|
if (WARN_ON_ONCE(!nb))
|
|
continue;
|
|
|
|
if (nb->nb_id == nb_id) {
|
|
*onln = cpuc->amd_nb;
|
|
cpuc->amd_nb = nb;
|
|
break;
|
|
}
|
|
}
|
|
|
|
cpuc->amd_nb->nb_id = nb_id;
|
|
cpuc->amd_nb->refcnt++;
|
|
}
|
|
|
|
static void amd_pmu_cpu_dead(int cpu)
|
|
{
|
|
struct cpu_hw_events *cpuhw;
|
|
|
|
if (!x86_pmu.amd_nb_constraints)
|
|
return;
|
|
|
|
cpuhw = &per_cpu(cpu_hw_events, cpu);
|
|
|
|
if (cpuhw->amd_nb) {
|
|
struct amd_nb *nb = cpuhw->amd_nb;
|
|
|
|
if (nb->nb_id == -1 || --nb->refcnt == 0)
|
|
kfree(nb);
|
|
|
|
cpuhw->amd_nb = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* When a PMC counter overflows, an NMI is used to process the event and
|
|
* reset the counter. NMI latency can result in the counter being updated
|
|
* before the NMI can run, which can result in what appear to be spurious
|
|
* NMIs. This function is intended to wait for the NMI to run and reset
|
|
* the counter to avoid possible unhandled NMI messages.
|
|
*/
|
|
#define OVERFLOW_WAIT_COUNT 50
|
|
|
|
static void amd_pmu_wait_on_overflow(int idx)
|
|
{
|
|
unsigned int i;
|
|
u64 counter;
|
|
|
|
/*
|
|
* Wait for the counter to be reset if it has overflowed. This loop
|
|
* should exit very, very quickly, but just in case, don't wait
|
|
* forever...
|
|
*/
|
|
for (i = 0; i < OVERFLOW_WAIT_COUNT; i++) {
|
|
rdmsrl(x86_pmu_event_addr(idx), counter);
|
|
if (counter & (1ULL << (x86_pmu.cntval_bits - 1)))
|
|
break;
|
|
|
|
/* Might be in IRQ context, so can't sleep */
|
|
udelay(1);
|
|
}
|
|
}
|
|
|
|
static void amd_pmu_disable_all(void)
|
|
{
|
|
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
|
|
int idx;
|
|
|
|
x86_pmu_disable_all();
|
|
|
|
/*
|
|
* This shouldn't be called from NMI context, but add a safeguard here
|
|
* to return, since if we're in NMI context we can't wait for an NMI
|
|
* to reset an overflowed counter value.
|
|
*/
|
|
if (in_nmi())
|
|
return;
|
|
|
|
/*
|
|
* Check each counter for overflow and wait for it to be reset by the
|
|
* NMI if it has overflowed. This relies on the fact that all active
|
|
* counters are always enabled when this function is caled and
|
|
* ARCH_PERFMON_EVENTSEL_INT is always set.
|
|
*/
|
|
for (idx = 0; idx < x86_pmu.num_counters; idx++) {
|
|
if (!test_bit(idx, cpuc->active_mask))
|
|
continue;
|
|
|
|
amd_pmu_wait_on_overflow(idx);
|
|
}
|
|
}
|
|
|
|
static void amd_pmu_disable_event(struct perf_event *event)
|
|
{
|
|
x86_pmu_disable_event(event);
|
|
|
|
/*
|
|
* This can be called from NMI context (via x86_pmu_stop). The counter
|
|
* may have overflowed, but either way, we'll never see it get reset
|
|
* by the NMI if we're already in the NMI. And the NMI latency support
|
|
* below will take care of any pending NMI that might have been
|
|
* generated by the overflow.
|
|
*/
|
|
if (in_nmi())
|
|
return;
|
|
|
|
amd_pmu_wait_on_overflow(event->hw.idx);
|
|
}
|
|
|
|
/*
|
|
* Because of NMI latency, if multiple PMC counters are active or other sources
|
|
* of NMIs are received, the perf NMI handler can handle one or more overflowed
|
|
* PMC counters outside of the NMI associated with the PMC overflow. If the NMI
|
|
* doesn't arrive at the LAPIC in time to become a pending NMI, then the kernel
|
|
* back-to-back NMI support won't be active. This PMC handler needs to take into
|
|
* account that this can occur, otherwise this could result in unknown NMI
|
|
* messages being issued. Examples of this is PMC overflow while in the NMI
|
|
* handler when multiple PMCs are active or PMC overflow while handling some
|
|
* other source of an NMI.
|
|
*
|
|
* Attempt to mitigate this by creating an NMI window in which un-handled NMIs
|
|
* received during this window will be claimed. This prevents extending the
|
|
* window past when it is possible that latent NMIs should be received. The
|
|
* per-CPU perf_nmi_tstamp will be set to the window end time whenever perf has
|
|
* handled a counter. When an un-handled NMI is received, it will be claimed
|
|
* only if arriving within that window.
|
|
*/
|
|
static int amd_pmu_handle_irq(struct pt_regs *regs)
|
|
{
|
|
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
|
|
int active, handled;
|
|
|
|
/*
|
|
* Obtain the active count before calling x86_pmu_handle_irq() since
|
|
* it is possible that x86_pmu_handle_irq() may make a counter
|
|
* inactive (through x86_pmu_stop).
|
|
*/
|
|
active = __bitmap_weight(cpuc->active_mask, X86_PMC_IDX_MAX);
|
|
|
|
/* Process any counter overflows */
|
|
handled = x86_pmu_handle_irq(regs);
|
|
|
|
/*
|
|
* If a counter was handled, record a timestamp such that un-handled
|
|
* NMIs will be claimed if arriving within that window.
|
|
*/
|
|
if (handled) {
|
|
this_cpu_write(perf_nmi_tstamp,
|
|
jiffies + perf_nmi_window);
|
|
|
|
return handled;
|
|
}
|
|
|
|
if (time_after(jiffies, this_cpu_read(perf_nmi_tstamp)))
|
|
return NMI_DONE;
|
|
|
|
return NMI_HANDLED;
|
|
}
|
|
|
|
static struct event_constraint *
|
|
amd_get_event_constraints(struct cpu_hw_events *cpuc, int idx,
|
|
struct perf_event *event)
|
|
{
|
|
/*
|
|
* if not NB event or no NB, then no constraints
|
|
*/
|
|
if (!(amd_has_nb(cpuc) && amd_is_nb_event(&event->hw)))
|
|
return &unconstrained;
|
|
|
|
return __amd_get_nb_event_constraints(cpuc, event, NULL);
|
|
}
|
|
|
|
static void amd_put_event_constraints(struct cpu_hw_events *cpuc,
|
|
struct perf_event *event)
|
|
{
|
|
if (amd_has_nb(cpuc) && amd_is_nb_event(&event->hw))
|
|
__amd_put_nb_event_constraints(cpuc, event);
|
|
}
|
|
|
|
PMU_FORMAT_ATTR(event, "config:0-7,32-35");
|
|
PMU_FORMAT_ATTR(umask, "config:8-15" );
|
|
PMU_FORMAT_ATTR(edge, "config:18" );
|
|
PMU_FORMAT_ATTR(inv, "config:23" );
|
|
PMU_FORMAT_ATTR(cmask, "config:24-31" );
|
|
|
|
static struct attribute *amd_format_attr[] = {
|
|
&format_attr_event.attr,
|
|
&format_attr_umask.attr,
|
|
&format_attr_edge.attr,
|
|
&format_attr_inv.attr,
|
|
&format_attr_cmask.attr,
|
|
NULL,
|
|
};
|
|
|
|
/* AMD Family 15h */
|
|
|
|
#define AMD_EVENT_TYPE_MASK 0x000000F0ULL
|
|
|
|
#define AMD_EVENT_FP 0x00000000ULL ... 0x00000010ULL
|
|
#define AMD_EVENT_LS 0x00000020ULL ... 0x00000030ULL
|
|
#define AMD_EVENT_DC 0x00000040ULL ... 0x00000050ULL
|
|
#define AMD_EVENT_CU 0x00000060ULL ... 0x00000070ULL
|
|
#define AMD_EVENT_IC_DE 0x00000080ULL ... 0x00000090ULL
|
|
#define AMD_EVENT_EX_LS 0x000000C0ULL
|
|
#define AMD_EVENT_DE 0x000000D0ULL
|
|
#define AMD_EVENT_NB 0x000000E0ULL ... 0x000000F0ULL
|
|
|
|
/*
|
|
* AMD family 15h event code/PMC mappings:
|
|
*
|
|
* type = event_code & 0x0F0:
|
|
*
|
|
* 0x000 FP PERF_CTL[5:3]
|
|
* 0x010 FP PERF_CTL[5:3]
|
|
* 0x020 LS PERF_CTL[5:0]
|
|
* 0x030 LS PERF_CTL[5:0]
|
|
* 0x040 DC PERF_CTL[5:0]
|
|
* 0x050 DC PERF_CTL[5:0]
|
|
* 0x060 CU PERF_CTL[2:0]
|
|
* 0x070 CU PERF_CTL[2:0]
|
|
* 0x080 IC/DE PERF_CTL[2:0]
|
|
* 0x090 IC/DE PERF_CTL[2:0]
|
|
* 0x0A0 ---
|
|
* 0x0B0 ---
|
|
* 0x0C0 EX/LS PERF_CTL[5:0]
|
|
* 0x0D0 DE PERF_CTL[2:0]
|
|
* 0x0E0 NB NB_PERF_CTL[3:0]
|
|
* 0x0F0 NB NB_PERF_CTL[3:0]
|
|
*
|
|
* Exceptions:
|
|
*
|
|
* 0x000 FP PERF_CTL[3], PERF_CTL[5:3] (*)
|
|
* 0x003 FP PERF_CTL[3]
|
|
* 0x004 FP PERF_CTL[3], PERF_CTL[5:3] (*)
|
|
* 0x00B FP PERF_CTL[3]
|
|
* 0x00D FP PERF_CTL[3]
|
|
* 0x023 DE PERF_CTL[2:0]
|
|
* 0x02D LS PERF_CTL[3]
|
|
* 0x02E LS PERF_CTL[3,0]
|
|
* 0x031 LS PERF_CTL[2:0] (**)
|
|
* 0x043 CU PERF_CTL[2:0]
|
|
* 0x045 CU PERF_CTL[2:0]
|
|
* 0x046 CU PERF_CTL[2:0]
|
|
* 0x054 CU PERF_CTL[2:0]
|
|
* 0x055 CU PERF_CTL[2:0]
|
|
* 0x08F IC PERF_CTL[0]
|
|
* 0x187 DE PERF_CTL[0]
|
|
* 0x188 DE PERF_CTL[0]
|
|
* 0x0DB EX PERF_CTL[5:0]
|
|
* 0x0DC LS PERF_CTL[5:0]
|
|
* 0x0DD LS PERF_CTL[5:0]
|
|
* 0x0DE LS PERF_CTL[5:0]
|
|
* 0x0DF LS PERF_CTL[5:0]
|
|
* 0x1C0 EX PERF_CTL[5:3]
|
|
* 0x1D6 EX PERF_CTL[5:0]
|
|
* 0x1D8 EX PERF_CTL[5:0]
|
|
*
|
|
* (*) depending on the umask all FPU counters may be used
|
|
* (**) only one unitmask enabled at a time
|
|
*/
|
|
|
|
static struct event_constraint amd_f15_PMC0 = EVENT_CONSTRAINT(0, 0x01, 0);
|
|
static struct event_constraint amd_f15_PMC20 = EVENT_CONSTRAINT(0, 0x07, 0);
|
|
static struct event_constraint amd_f15_PMC3 = EVENT_CONSTRAINT(0, 0x08, 0);
|
|
static struct event_constraint amd_f15_PMC30 = EVENT_CONSTRAINT_OVERLAP(0, 0x09, 0);
|
|
static struct event_constraint amd_f15_PMC50 = EVENT_CONSTRAINT(0, 0x3F, 0);
|
|
static struct event_constraint amd_f15_PMC53 = EVENT_CONSTRAINT(0, 0x38, 0);
|
|
|
|
static struct event_constraint *
|
|
amd_get_event_constraints_f15h(struct cpu_hw_events *cpuc, int idx,
|
|
struct perf_event *event)
|
|
{
|
|
struct hw_perf_event *hwc = &event->hw;
|
|
unsigned int event_code = amd_get_event_code(hwc);
|
|
|
|
switch (event_code & AMD_EVENT_TYPE_MASK) {
|
|
case AMD_EVENT_FP:
|
|
switch (event_code) {
|
|
case 0x000:
|
|
if (!(hwc->config & 0x0000F000ULL))
|
|
break;
|
|
if (!(hwc->config & 0x00000F00ULL))
|
|
break;
|
|
return &amd_f15_PMC3;
|
|
case 0x004:
|
|
if (hweight_long(hwc->config & ARCH_PERFMON_EVENTSEL_UMASK) <= 1)
|
|
break;
|
|
return &amd_f15_PMC3;
|
|
case 0x003:
|
|
case 0x00B:
|
|
case 0x00D:
|
|
return &amd_f15_PMC3;
|
|
}
|
|
return &amd_f15_PMC53;
|
|
case AMD_EVENT_LS:
|
|
case AMD_EVENT_DC:
|
|
case AMD_EVENT_EX_LS:
|
|
switch (event_code) {
|
|
case 0x023:
|
|
case 0x043:
|
|
case 0x045:
|
|
case 0x046:
|
|
case 0x054:
|
|
case 0x055:
|
|
return &amd_f15_PMC20;
|
|
case 0x02D:
|
|
return &amd_f15_PMC3;
|
|
case 0x02E:
|
|
return &amd_f15_PMC30;
|
|
case 0x031:
|
|
if (hweight_long(hwc->config & ARCH_PERFMON_EVENTSEL_UMASK) <= 1)
|
|
return &amd_f15_PMC20;
|
|
return &emptyconstraint;
|
|
case 0x1C0:
|
|
return &amd_f15_PMC53;
|
|
default:
|
|
return &amd_f15_PMC50;
|
|
}
|
|
case AMD_EVENT_CU:
|
|
case AMD_EVENT_IC_DE:
|
|
case AMD_EVENT_DE:
|
|
switch (event_code) {
|
|
case 0x08F:
|
|
case 0x187:
|
|
case 0x188:
|
|
return &amd_f15_PMC0;
|
|
case 0x0DB ... 0x0DF:
|
|
case 0x1D6:
|
|
case 0x1D8:
|
|
return &amd_f15_PMC50;
|
|
default:
|
|
return &amd_f15_PMC20;
|
|
}
|
|
case AMD_EVENT_NB:
|
|
/* moved to uncore.c */
|
|
return &emptyconstraint;
|
|
default:
|
|
return &emptyconstraint;
|
|
}
|
|
}
|
|
|
|
static ssize_t amd_event_sysfs_show(char *page, u64 config)
|
|
{
|
|
u64 event = (config & ARCH_PERFMON_EVENTSEL_EVENT) |
|
|
(config & AMD64_EVENTSEL_EVENT) >> 24;
|
|
|
|
return x86_event_sysfs_show(page, config, event);
|
|
}
|
|
|
|
static __initconst const struct x86_pmu amd_pmu = {
|
|
.name = "AMD",
|
|
.handle_irq = amd_pmu_handle_irq,
|
|
.disable_all = amd_pmu_disable_all,
|
|
.enable_all = x86_pmu_enable_all,
|
|
.enable = x86_pmu_enable_event,
|
|
.disable = amd_pmu_disable_event,
|
|
.hw_config = amd_pmu_hw_config,
|
|
.schedule_events = x86_schedule_events,
|
|
.eventsel = MSR_K7_EVNTSEL0,
|
|
.perfctr = MSR_K7_PERFCTR0,
|
|
.addr_offset = amd_pmu_addr_offset,
|
|
.event_map = amd_pmu_event_map,
|
|
.max_events = ARRAY_SIZE(amd_perfmon_event_map),
|
|
.num_counters = AMD64_NUM_COUNTERS,
|
|
.cntval_bits = 48,
|
|
.cntval_mask = (1ULL << 48) - 1,
|
|
.apic = 1,
|
|
/* use highest bit to detect overflow */
|
|
.max_period = (1ULL << 47) - 1,
|
|
.get_event_constraints = amd_get_event_constraints,
|
|
.put_event_constraints = amd_put_event_constraints,
|
|
|
|
.format_attrs = amd_format_attr,
|
|
.events_sysfs_show = amd_event_sysfs_show,
|
|
|
|
.cpu_prepare = amd_pmu_cpu_prepare,
|
|
.cpu_starting = amd_pmu_cpu_starting,
|
|
.cpu_dead = amd_pmu_cpu_dead,
|
|
|
|
.amd_nb_constraints = 1,
|
|
};
|
|
|
|
static int __init amd_core_pmu_init(void)
|
|
{
|
|
if (!boot_cpu_has(X86_FEATURE_PERFCTR_CORE))
|
|
return 0;
|
|
|
|
/* Avoid calulating the value each time in the NMI handler */
|
|
perf_nmi_window = msecs_to_jiffies(100);
|
|
|
|
switch (boot_cpu_data.x86) {
|
|
case 0x15:
|
|
pr_cont("Fam15h ");
|
|
x86_pmu.get_event_constraints = amd_get_event_constraints_f15h;
|
|
break;
|
|
case 0x17:
|
|
pr_cont("Fam17h ");
|
|
/*
|
|
* In family 17h, there are no event constraints in the PMC hardware.
|
|
* We fallback to using default amd_get_event_constraints.
|
|
*/
|
|
break;
|
|
case 0x18:
|
|
pr_cont("Fam18h ");
|
|
/* Using default amd_get_event_constraints. */
|
|
break;
|
|
default:
|
|
pr_err("core perfctr but no constraints; unknown hardware!\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
/*
|
|
* If core performance counter extensions exists, we must use
|
|
* MSR_F15H_PERF_CTL/MSR_F15H_PERF_CTR msrs. See also
|
|
* amd_pmu_addr_offset().
|
|
*/
|
|
x86_pmu.eventsel = MSR_F15H_PERF_CTL;
|
|
x86_pmu.perfctr = MSR_F15H_PERF_CTR;
|
|
x86_pmu.num_counters = AMD64_NUM_COUNTERS_CORE;
|
|
/*
|
|
* AMD Core perfctr has separate MSRs for the NB events, see
|
|
* the amd/uncore.c driver.
|
|
*/
|
|
x86_pmu.amd_nb_constraints = 0;
|
|
|
|
pr_cont("core perfctr, ");
|
|
return 0;
|
|
}
|
|
|
|
__init int amd_pmu_init(void)
|
|
{
|
|
int ret;
|
|
|
|
/* Performance-monitoring supported from K7 and later: */
|
|
if (boot_cpu_data.x86 < 6)
|
|
return -ENODEV;
|
|
|
|
x86_pmu = amd_pmu;
|
|
|
|
ret = amd_core_pmu_init();
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (num_possible_cpus() == 1) {
|
|
/*
|
|
* No point in allocating data structures to serialize
|
|
* against other CPUs, when there is only the one CPU.
|
|
*/
|
|
x86_pmu.amd_nb_constraints = 0;
|
|
}
|
|
|
|
if (boot_cpu_data.x86 >= 0x17)
|
|
memcpy(hw_cache_event_ids, amd_hw_cache_event_ids_f17h, sizeof(hw_cache_event_ids));
|
|
else
|
|
memcpy(hw_cache_event_ids, amd_hw_cache_event_ids, sizeof(hw_cache_event_ids));
|
|
|
|
return 0;
|
|
}
|
|
|
|
void amd_pmu_enable_virt(void)
|
|
{
|
|
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
|
|
|
|
cpuc->perf_ctr_virt_mask = 0;
|
|
|
|
/* Reload all events */
|
|
amd_pmu_disable_all();
|
|
x86_pmu_enable_all(0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(amd_pmu_enable_virt);
|
|
|
|
void amd_pmu_disable_virt(void)
|
|
{
|
|
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
|
|
|
|
/*
|
|
* We only mask out the Host-only bit so that host-only counting works
|
|
* when SVM is disabled. If someone sets up a guest-only counter when
|
|
* SVM is disabled the Guest-only bits still gets set and the counter
|
|
* will not count anything.
|
|
*/
|
|
cpuc->perf_ctr_virt_mask = AMD64_EVENTSEL_HOSTONLY;
|
|
|
|
/* Reload all events */
|
|
amd_pmu_disable_all();
|
|
x86_pmu_enable_all(0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(amd_pmu_disable_virt);
|