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-rw-r--r--arch/nds32/kernel/perf_event_cpu.c299
1 files changed, 299 insertions, 0 deletions
diff --git a/arch/nds32/kernel/perf_event_cpu.c b/arch/nds32/kernel/perf_event_cpu.c
index a6e723d0fdbc..5e00ce54d0ff 100644
--- a/arch/nds32/kernel/perf_event_cpu.c
+++ b/arch/nds32/kernel/perf_event_cpu.c
@@ -1193,6 +1193,305 @@ static int __init register_pmu_driver(void)
device_initcall(register_pmu_driver);
+/*
+ * References: arch/nds32/kernel/traps.c:__dump()
+ * You will need to know the NDS ABI first.
+ */
+static int unwind_frame_kernel(struct stackframe *frame)
+{
+ int graph = 0;
+#ifdef CONFIG_FRAME_POINTER
+ /* 0x3 means misalignment */
+ if (!kstack_end((void *)frame->fp) &&
+ !((unsigned long)frame->fp & 0x3) &&
+ ((unsigned long)frame->fp >= TASK_SIZE)) {
+ /*
+ * The array index is based on the ABI, the below graph
+ * illustrate the reasons.
+ * Function call procedure: "smw" and "lmw" will always
+ * update SP and FP for you automatically.
+ *
+ * Stack Relative Address
+ * | | 0
+ * ----
+ * |LP| <-- SP(before smw) <-- FP(after smw) -1
+ * ----
+ * |FP| -2
+ * ----
+ * | | <-- SP(after smw) -3
+ */
+ frame->lp = ((unsigned long *)frame->fp)[-1];
+ frame->fp = ((unsigned long *)frame->fp)[FP_OFFSET];
+ /* make sure CONFIG_FUNCTION_GRAPH_TRACER is turned on */
+ if (__kernel_text_address(frame->lp))
+ frame->lp = ftrace_graph_ret_addr
+ (NULL, &graph, frame->lp, NULL);
+
+ return 0;
+ } else {
+ return -EPERM;
+ }
+#else
+ /*
+ * You can refer to arch/nds32/kernel/traps.c:__dump()
+ * Treat "sp" as "fp", but the "sp" is one frame ahead of "fp".
+ * And, the "sp" is not always correct.
+ *
+ * Stack Relative Address
+ * | | 0
+ * ----
+ * |LP| <-- SP(before smw) -1
+ * ----
+ * | | <-- SP(after smw) -2
+ * ----
+ */
+ if (!kstack_end((void *)frame->sp)) {
+ frame->lp = ((unsigned long *)frame->sp)[1];
+ /* TODO: How to deal with the value in first
+ * "sp" is not correct?
+ */
+ if (__kernel_text_address(frame->lp))
+ frame->lp = ftrace_graph_ret_addr
+ (tsk, &graph, frame->lp, NULL);
+
+ frame->sp = ((unsigned long *)frame->sp) + 1;
+
+ return 0;
+ } else {
+ return -EPERM;
+ }
+#endif
+}
+
+static void notrace
+walk_stackframe(struct stackframe *frame,
+ int (*fn_record)(struct stackframe *, void *),
+ void *data)
+{
+ while (1) {
+ int ret;
+
+ if (fn_record(frame, data))
+ break;
+
+ ret = unwind_frame_kernel(frame);
+ if (ret < 0)
+ break;
+ }
+}
+
+/*
+ * Gets called by walk_stackframe() for every stackframe. This will be called
+ * whist unwinding the stackframe and is like a subroutine return so we use
+ * the PC.
+ */
+static int callchain_trace(struct stackframe *fr, void *data)
+{
+ struct perf_callchain_entry_ctx *entry = data;
+
+ perf_callchain_store(entry, fr->lp);
+ return 0;
+}
+
+/*
+ * Get the return address for a single stackframe and return a pointer to the
+ * next frame tail.
+ */
+static unsigned long
+user_backtrace(struct perf_callchain_entry_ctx *entry, unsigned long fp)
+{
+ struct frame_tail buftail;
+ unsigned long lp = 0;
+ unsigned long *user_frame_tail =
+ (unsigned long *)(fp - (unsigned long)sizeof(buftail));
+
+ /* Check accessibility of one struct frame_tail beyond */
+ if (!access_ok(VERIFY_READ, user_frame_tail, sizeof(buftail)))
+ return 0;
+ if (__copy_from_user_inatomic
+ (&buftail, user_frame_tail, sizeof(buftail)))
+ return 0;
+
+ /*
+ * Refer to unwind_frame_kernel() for more illurstration
+ */
+ lp = buftail.stack_lp; /* ((unsigned long *)fp)[-1] */
+ fp = buftail.stack_fp; /* ((unsigned long *)fp)[FP_OFFSET] */
+ perf_callchain_store(entry, lp);
+ return fp;
+}
+
+static unsigned long
+user_backtrace_opt_size(struct perf_callchain_entry_ctx *entry,
+ unsigned long fp)
+{
+ struct frame_tail_opt_size buftail;
+ unsigned long lp = 0;
+
+ unsigned long *user_frame_tail =
+ (unsigned long *)(fp - (unsigned long)sizeof(buftail));
+
+ /* Check accessibility of one struct frame_tail beyond */
+ if (!access_ok(VERIFY_READ, user_frame_tail, sizeof(buftail)))
+ return 0;
+ if (__copy_from_user_inatomic
+ (&buftail, user_frame_tail, sizeof(buftail)))
+ return 0;
+
+ /*
+ * Refer to unwind_frame_kernel() for more illurstration
+ */
+ lp = buftail.stack_lp; /* ((unsigned long *)fp)[-1] */
+ fp = buftail.stack_fp; /* ((unsigned long *)fp)[FP_OFFSET] */
+
+ perf_callchain_store(entry, lp);
+ return fp;
+}
+
+/*
+ * This will be called when the target is in user mode
+ * This function will only be called when we use
+ * "PERF_SAMPLE_CALLCHAIN" in
+ * kernel/events/core.c:perf_prepare_sample()
+ *
+ * How to trigger perf_callchain_[user/kernel] :
+ * $ perf record -e cpu-clock --call-graph fp ./program
+ * $ perf report --call-graph
+ */
+unsigned long leaf_fp;
+void
+perf_callchain_user(struct perf_callchain_entry_ctx *entry,
+ struct pt_regs *regs)
+{
+ unsigned long fp = 0;
+ unsigned long gp = 0;
+ unsigned long lp = 0;
+ unsigned long sp = 0;
+ unsigned long *user_frame_tail;
+
+ leaf_fp = 0;
+
+ if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
+ /* We don't support guest os callchain now */
+ return;
+ }
+
+ perf_callchain_store(entry, regs->ipc);
+ fp = regs->fp;
+ gp = regs->gp;
+ lp = regs->lp;
+ sp = regs->sp;
+ if (entry->nr < PERF_MAX_STACK_DEPTH &&
+ (unsigned long)fp && !((unsigned long)fp & 0x7) && fp > sp) {
+ user_frame_tail =
+ (unsigned long *)(fp - (unsigned long)sizeof(fp));
+
+ if (!access_ok(VERIFY_READ, user_frame_tail, sizeof(fp)))
+ return;
+
+ if (__copy_from_user_inatomic
+ (&leaf_fp, user_frame_tail, sizeof(fp)))
+ return;
+
+ if (leaf_fp == lp) {
+ /*
+ * Maybe this is non leaf function
+ * with optimize for size,
+ * or maybe this is the function
+ * with optimize for size
+ */
+ struct frame_tail buftail;
+
+ user_frame_tail =
+ (unsigned long *)(fp -
+ (unsigned long)sizeof(buftail));
+
+ if (!access_ok
+ (VERIFY_READ, user_frame_tail, sizeof(buftail)))
+ return;
+
+ if (__copy_from_user_inatomic
+ (&buftail, user_frame_tail, sizeof(buftail)))
+ return;
+
+ if (buftail.stack_fp == gp) {
+ /* non leaf function with optimize
+ * for size condition
+ */
+ struct frame_tail_opt_size buftail_opt_size;
+
+ user_frame_tail =
+ (unsigned long *)(fp - (unsigned long)
+ sizeof(buftail_opt_size));
+
+ if (!access_ok(VERIFY_READ, user_frame_tail,
+ sizeof(buftail_opt_size)))
+ return;
+
+ if (__copy_from_user_inatomic
+ (&buftail_opt_size, user_frame_tail,
+ sizeof(buftail_opt_size)))
+ return;
+
+ perf_callchain_store(entry, lp);
+ fp = buftail_opt_size.stack_fp;
+
+ while ((entry->nr < PERF_MAX_STACK_DEPTH) &&
+ (unsigned long)fp &&
+ !((unsigned long)fp & 0x7) &&
+ fp > sp) {
+ sp = fp;
+ fp = user_backtrace_opt_size(entry, fp);
+ }
+
+ } else {
+ /* this is the function
+ * without optimize for size
+ */
+ fp = buftail.stack_fp;
+ perf_callchain_store(entry, lp);
+ while ((entry->nr < PERF_MAX_STACK_DEPTH) &&
+ (unsigned long)fp &&
+ !((unsigned long)fp & 0x7) &&
+ fp > sp) {
+ sp = fp;
+ fp = user_backtrace(entry, fp);
+ }
+ }
+ } else {
+ /* this is leaf function */
+ fp = leaf_fp;
+ perf_callchain_store(entry, lp);
+
+ /* previous function callcahin */
+ while ((entry->nr < PERF_MAX_STACK_DEPTH) &&
+ (unsigned long)fp &&
+ !((unsigned long)fp & 0x7) && fp > sp) {
+ sp = fp;
+ fp = user_backtrace(entry, fp);
+ }
+ }
+ return;
+ }
+}
+
+/* This will be called when the target is in kernel mode */
+void
+perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
+ struct pt_regs *regs)
+{
+ struct stackframe fr;
+
+ if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
+ /* We don't support guest os callchain now */
+ return;
+ }
+ fr.fp = regs->fp;
+ fr.lp = regs->lp;
+ fr.sp = regs->sp;
+ walk_stackframe(&fr, callchain_trace, entry);
+}
+
unsigned long perf_instruction_pointer(struct pt_regs *regs)
{
/* However, NDS32 does not support virtualization */