summaryrefslogtreecommitdiff
path: root/arch/riscv/kernel/mcount-dyn.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/riscv/kernel/mcount-dyn.S')
-rw-r--r--arch/riscv/kernel/mcount-dyn.S264
1 files changed, 106 insertions, 158 deletions
diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S
index b7561288e8da..48f6c4f7dca0 100644
--- a/arch/riscv/kernel/mcount-dyn.S
+++ b/arch/riscv/kernel/mcount-dyn.S
@@ -13,7 +13,6 @@
.text
-#define FENTRY_RA_OFFSET 8
#define ABI_SIZE_ON_STACK 80
#define ABI_A0 0
#define ABI_A1 8
@@ -56,204 +55,153 @@
addi sp, sp, ABI_SIZE_ON_STACK
.endm
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-
/**
-* SAVE_ABI_REGS - save regs against the pt_regs struct
-*
-* @all: tell if saving all the regs
-*
-* If all is set, all the regs will be saved, otherwise only ABI
-* related regs (a0-a7,epc,ra and optional s0) will be saved.
+* SAVE_ABI_REGS - save regs against the ftrace_regs struct
*
* After the stack is established,
*
* 0(sp) stores the PC of the traced function which can be accessed
-* by &(fregs)->regs->epc in tracing function. Note that the real
-* function entry address should be computed with -FENTRY_RA_OFFSET.
+* by &(fregs)->epc in tracing function.
*
* 8(sp) stores the function return address (i.e. parent IP) that
-* can be accessed by &(fregs)->regs->ra in tracing function.
+* can be accessed by &(fregs)->ra in tracing function.
*
* The other regs are saved at the respective localtion and accessed
-* by the respective pt_regs member.
+* by the respective ftrace_regs member.
*
* Here is the layout of stack for your reference.
*
* PT_SIZE_ON_STACK -> +++++++++
* + ..... +
-* + t3-t6 +
-* + s2-s11+
* + a0-a7 + --++++-> ftrace_caller saved
-* + s1 + +
-* + s0 + --+
-* + t0-t2 + +
-* + tp + +
-* + gp + +
+* + t1 + --++++-> direct tramp address
+* + s0 + --+ // frame pointer
* + sp + +
* + ra + --+ // parent IP
* sp -> + epc + --+ // PC
* +++++++++
**/
- .macro SAVE_ABI_REGS, all=0
- addi sp, sp, -PT_SIZE_ON_STACK
-
- REG_S t0, PT_EPC(sp)
- REG_S x1, PT_RA(sp)
-
- // save the ABI regs
-
- REG_S x10, PT_A0(sp)
- REG_S x11, PT_A1(sp)
- REG_S x12, PT_A2(sp)
- REG_S x13, PT_A3(sp)
- REG_S x14, PT_A4(sp)
- REG_S x15, PT_A5(sp)
- REG_S x16, PT_A6(sp)
- REG_S x17, PT_A7(sp)
-
- // save the leftover regs
-
- .if \all == 1
- REG_S x2, PT_SP(sp)
- REG_S x3, PT_GP(sp)
- REG_S x4, PT_TP(sp)
- REG_S x5, PT_T0(sp)
- REG_S x6, PT_T1(sp)
- REG_S x7, PT_T2(sp)
- REG_S x8, PT_S0(sp)
- REG_S x9, PT_S1(sp)
- REG_S x18, PT_S2(sp)
- REG_S x19, PT_S3(sp)
- REG_S x20, PT_S4(sp)
- REG_S x21, PT_S5(sp)
- REG_S x22, PT_S6(sp)
- REG_S x23, PT_S7(sp)
- REG_S x24, PT_S8(sp)
- REG_S x25, PT_S9(sp)
- REG_S x26, PT_S10(sp)
- REG_S x27, PT_S11(sp)
- REG_S x28, PT_T3(sp)
- REG_S x29, PT_T4(sp)
- REG_S x30, PT_T5(sp)
- REG_S x31, PT_T6(sp)
-
- // save s0 if FP_TEST defined
-
- .else
+ .macro SAVE_ABI_REGS
+ addi sp, sp, -FREGS_SIZE_ON_STACK
+ REG_S t0, FREGS_EPC(sp)
+ REG_S x1, FREGS_RA(sp)
#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
- REG_S x8, PT_S0(sp)
+ REG_S x8, FREGS_S0(sp)
#endif
- .endif
+ REG_S x6, FREGS_T1(sp)
+#ifdef CONFIG_CC_IS_CLANG
+ REG_S x7, FREGS_T2(sp)
+ REG_S x28, FREGS_T3(sp)
+ REG_S x29, FREGS_T4(sp)
+ REG_S x30, FREGS_T5(sp)
+ REG_S x31, FREGS_T6(sp)
+#endif
+ // save the arguments
+ REG_S x10, FREGS_A0(sp)
+ REG_S x11, FREGS_A1(sp)
+ REG_S x12, FREGS_A2(sp)
+ REG_S x13, FREGS_A3(sp)
+ REG_S x14, FREGS_A4(sp)
+ REG_S x15, FREGS_A5(sp)
+ REG_S x16, FREGS_A6(sp)
+ REG_S x17, FREGS_A7(sp)
+ mv a0, sp
+ addi a0, a0, FREGS_SIZE_ON_STACK
+ REG_S a0, FREGS_SP(sp) // Put original SP on stack
.endm
- .macro RESTORE_ABI_REGS, all=0
- REG_L t0, PT_EPC(sp)
- REG_L x1, PT_RA(sp)
- REG_L x10, PT_A0(sp)
- REG_L x11, PT_A1(sp)
- REG_L x12, PT_A2(sp)
- REG_L x13, PT_A3(sp)
- REG_L x14, PT_A4(sp)
- REG_L x15, PT_A5(sp)
- REG_L x16, PT_A6(sp)
- REG_L x17, PT_A7(sp)
-
- .if \all == 1
- REG_L x2, PT_SP(sp)
- REG_L x3, PT_GP(sp)
- REG_L x4, PT_TP(sp)
- REG_L x6, PT_T1(sp)
- REG_L x7, PT_T2(sp)
- REG_L x8, PT_S0(sp)
- REG_L x9, PT_S1(sp)
- REG_L x18, PT_S2(sp)
- REG_L x19, PT_S3(sp)
- REG_L x20, PT_S4(sp)
- REG_L x21, PT_S5(sp)
- REG_L x22, PT_S6(sp)
- REG_L x23, PT_S7(sp)
- REG_L x24, PT_S8(sp)
- REG_L x25, PT_S9(sp)
- REG_L x26, PT_S10(sp)
- REG_L x27, PT_S11(sp)
- REG_L x28, PT_T3(sp)
- REG_L x29, PT_T4(sp)
- REG_L x30, PT_T5(sp)
- REG_L x31, PT_T6(sp)
-
- .else
+ .macro RESTORE_ABI_REGS
+ REG_L t0, FREGS_EPC(sp)
+ REG_L x1, FREGS_RA(sp)
#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
- REG_L x8, PT_S0(sp)
+ REG_L x8, FREGS_S0(sp)
#endif
- .endif
- addi sp, sp, PT_SIZE_ON_STACK
+ REG_L x6, FREGS_T1(sp)
+#ifdef CONFIG_CC_IS_CLANG
+ REG_L x7, FREGS_T2(sp)
+ REG_L x28, FREGS_T3(sp)
+ REG_L x29, FREGS_T4(sp)
+ REG_L x30, FREGS_T5(sp)
+ REG_L x31, FREGS_T6(sp)
+#endif
+ // restore the arguments
+ REG_L x10, FREGS_A0(sp)
+ REG_L x11, FREGS_A1(sp)
+ REG_L x12, FREGS_A2(sp)
+ REG_L x13, FREGS_A3(sp)
+ REG_L x14, FREGS_A4(sp)
+ REG_L x15, FREGS_A5(sp)
+ REG_L x16, FREGS_A6(sp)
+ REG_L x17, FREGS_A7(sp)
+
+ addi sp, sp, FREGS_SIZE_ON_STACK
.endm
.macro PREPARE_ARGS
- addi a0, t0, -FENTRY_RA_OFFSET
+ addi a0, t0, -MCOUNT_JALR_SIZE // ip (callsite's jalr insn)
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS
+ mv a1, ra // parent_ip
+ REG_L a2, -16(t0) // op
+ REG_L ra, FTRACE_OPS_FUNC(a2) // op->func
+#else
la a1, function_trace_op
- REG_L a2, 0(a1)
- mv a1, ra
- mv a3, sp
+ REG_L a2, 0(a1) // op
+ mv a1, ra // parent_ip
+#endif
+ mv a3, sp // regs
.endm
-#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
-
-#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
SYM_FUNC_START(ftrace_caller)
- SAVE_ABI
-
- addi a0, t0, -FENTRY_RA_OFFSET
- la a1, function_trace_op
- REG_L a2, 0(a1)
- mv a1, ra
- mv a3, sp
-
-SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL)
- call ftrace_stub
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS
+ /*
+ * When CALL_OPS is enabled (2 or 4) nops [8B] are placed before the
+ * function entry, these are later overwritten with the pointer to the
+ * associated struct ftrace_ops.
+ *
+ * -8: &ftrace_ops of the associated tracer function.
+ *<ftrace enable>:
+ * 0: auipc t0/ra, 0x?
+ * 4: jalr t0/ra, ?(t0/ra)
+ *
+ * -8: &ftrace_nop_ops
+ *<ftrace disable>:
+ * 0: nop
+ * 4: nop
+ *
+ * t0 is set to ip+8 after the jalr is executed at the callsite,
+ * so we find the associated op at t0-16.
+ */
+ REG_L t1, -16(t0) // op Should be SZ_REG instead of 16
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- addi a0, sp, ABI_RA
- REG_L a1, ABI_T0(sp)
- addi a1, a1, -FENTRY_RA_OFFSET
-#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
- mv a2, s0
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+ /*
+ * If the op has a direct call, handle it immediately without
+ * saving/restoring registers.
+ */
+ REG_L t1, FTRACE_OPS_DIRECT_CALL(t1)
+ bnez t1, ftrace_caller_direct
#endif
-SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL)
- call ftrace_stub
#endif
- RESTORE_ABI
- jr t0
-SYM_FUNC_END(ftrace_caller)
-
-#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
-SYM_FUNC_START(ftrace_regs_caller)
- mv t1, zero
- SAVE_ABI_REGS 1
- PREPARE_ARGS
-
-SYM_INNER_LABEL(ftrace_regs_call, SYM_L_GLOBAL)
- call ftrace_stub
-
- RESTORE_ABI_REGS 1
- bnez t1, .Ldirect
- jr t0
-.Ldirect:
- jr t1
-SYM_FUNC_END(ftrace_regs_caller)
-
-SYM_FUNC_START(ftrace_caller)
- SAVE_ABI_REGS 0
+ SAVE_ABI_REGS
PREPARE_ARGS
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS
+ jalr ra
+#else
SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL)
- call ftrace_stub
-
- RESTORE_ABI_REGS 0
+ REG_L ra, ftrace_call_dest
+ jalr ra, 0(ra)
+#endif
+ RESTORE_ABI_REGS
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+ bnez t1, ftrace_caller_direct
+#endif
jr t0
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+SYM_INNER_LABEL(ftrace_caller_direct, SYM_L_LOCAL)
+ jr t1
+#endif
SYM_FUNC_END(ftrace_caller)
-#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
SYM_CODE_START(ftrace_stub_direct_tramp)