Commit 98f92f2f authored by Deng-Cheng Zhu's avatar Deng-Cheng Zhu Committed by Ralf Baechle

MIPS, Perf-events: Work with the new callchain interface

This is the MIPS part of the following commits by Frederic Weisbecker:

- f72c1a93
    perf: Factorize callchain context handling

    Store the kernel and user contexts from the generic layer instead
    of archs, this gathers some repetitive code.

- 56962b44
    perf: Generalize some arch callchain code

    - Most archs use one callchain buffer per cpu, except x86 that needs
      to deal with NMIs. Provide a default perf_callchain_buffer()
      implementation that x86 overrides.

    - Centralize all the kernel/user regs handling and invoke new arch
      handlers from there: perf_callchain_user() / perf_callchain_kernel()
      That avoid all the user_mode(), current->mm checks and so...

    - Invert some parameters in perf_callchain_*() helpers: entry to the
      left, regs to the right, following the traditional (dst, src).

- 70791ce9
    perf: Generalize callchain_store()

    callchain_store() is the same on every archs, inline it in
    perf_event.h and rename it to perf_callchain_store() to avoid
    any collision.

    This removes repetitive code.

- c1a65932
    perf: Drop unappropriate tests on arch callchains

    Drop the TASK_RUNNING test on user tasks for callchains as
    this check doesn't seem to make any sense.

    Also remove the tests for !current that is not supposed to
    happen and current->pid as this should be handled at the
    generic level, with exclude_idle attribute.
Reported-by: default avatarWu Zhangjin <wuzhangjin@gmail.com>
Acked-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Acked-by: default avatarDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: default avatarDeng-Cheng Zhu <dengcheng.zhu@gmail.com>
To: a.p.zijlstra@chello.nl
To: will.deacon@arm.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: paulus@samba.org
Cc: mingo@elte.hu
Cc: acme@redhat.com
Cc: dengcheng.zhu@gmail.com
Cc: matt@console-pimps.org
Cc: sshtylyov@mvista.com
Patchwork: http://patchwork.linux-mips.org/patch/2014/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent c049b6a5
......@@ -534,21 +534,13 @@ handle_associated_event(struct cpu_hw_events *cpuc,
#include "perf_event_mipsxx.c"
/* Callchain handling code. */
static inline void
callchain_store(struct perf_callchain_entry *entry,
u64 ip)
{
if (entry->nr < PERF_MAX_STACK_DEPTH)
entry->ip[entry->nr++] = ip;
}
/*
* Leave userspace callchain empty for now. When we find a way to trace
* the user stack callchains, we add here.
*/
static void
perf_callchain_user(struct pt_regs *regs,
struct perf_callchain_entry *entry)
void perf_callchain_user(struct perf_callchain_entry *entry,
struct pt_regs *regs)
{
}
......@@ -561,23 +553,21 @@ static void save_raw_perf_callchain(struct perf_callchain_entry *entry,
while (!kstack_end(sp)) {
addr = *sp++;
if (__kernel_text_address(addr)) {
callchain_store(entry, addr);
perf_callchain_store(entry, addr);
if (entry->nr >= PERF_MAX_STACK_DEPTH)
break;
}
}
}
static void
perf_callchain_kernel(struct pt_regs *regs,
struct perf_callchain_entry *entry)
void perf_callchain_kernel(struct perf_callchain_entry *entry,
struct pt_regs *regs)
{
unsigned long sp = regs->regs[29];
#ifdef CONFIG_KALLSYMS
unsigned long ra = regs->regs[31];
unsigned long pc = regs->cp0_epc;
callchain_store(entry, PERF_CONTEXT_KERNEL);
if (raw_show_trace || !__kernel_text_address(pc)) {
unsigned long stack_page =
(unsigned long)task_stack_page(current);
......@@ -587,53 +577,12 @@ perf_callchain_kernel(struct pt_regs *regs,
return;
}
do {
callchain_store(entry, pc);
perf_callchain_store(entry, pc);
if (entry->nr >= PERF_MAX_STACK_DEPTH)
break;
pc = unwind_stack(current, &sp, pc, &ra);
} while (pc);
#else
callchain_store(entry, PERF_CONTEXT_KERNEL);
save_raw_perf_callchain(entry, sp);
#endif
}
static void
perf_do_callchain(struct pt_regs *regs,
struct perf_callchain_entry *entry)
{
int is_user;
if (!regs)
return;
is_user = user_mode(regs);
if (!current || !current->pid)
return;
if (is_user && current->state != TASK_RUNNING)
return;
if (!is_user) {
perf_callchain_kernel(regs, entry);
if (current->mm)
regs = task_pt_regs(current);
else
regs = NULL;
}
if (regs)
perf_callchain_user(regs, entry);
}
static DEFINE_PER_CPU(struct perf_callchain_entry, pmc_irq_entry);
struct perf_callchain_entry *
perf_callchain(struct pt_regs *regs)
{
struct perf_callchain_entry *entry = &__get_cpu_var(pmc_irq_entry);
entry->nr = 0;
perf_do_callchain(regs, entry);
return entry;
}
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