Commit f1ba46ee authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Will Deacon
Browse files

arm64: ftrace: eliminate literal pool entries 



Replace ldr xN, =<symbol> with adrp/add or adrp/ldr [as appropriate]
in the implementation of _mcount(), which may be called very often.

Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 80708677

arch/arm64/kernel/entry-ftrace.S

+11 −10
Original line number Diff line number Diff line
@@ -98,8 +98,8 @@ 
ENTRY(_mcount)

	mcount_enter



	ldr	x0, =ftrace_trace_function

	ldr	x2, [x0]

	adrp	x0, ftrace_trace_function

	ldr	x2, [x0, #:lo12:ftrace_trace_function]

	adr	x0, ftrace_stub

	cmp	x0, x2			// if (ftrace_trace_function

	b.eq	skip_ftrace_call	//     != ftrace_stub) {
@@ -115,14 +115,15 @@ skip_ftrace_call: // return; 
	mcount_exit			//   return;

					// }

skip_ftrace_call:

	ldr	x1, =ftrace_graph_return

	ldr	x2, [x1]		//   if ((ftrace_graph_return

	cmp	x0, x2			//        != ftrace_stub)

	b.ne	ftrace_graph_caller



	ldr	x1, =ftrace_graph_entry	//     || (ftrace_graph_entry

	ldr	x2, [x1]		//        != ftrace_graph_entry_stub))

	ldr	x0, =ftrace_graph_entry_stub

	adrp	x1, ftrace_graph_return

	ldr	x2, [x1, #:lo12:ftrace_graph_return]

	cmp	x0, x2			//   if ((ftrace_graph_return

	b.ne	ftrace_graph_caller	//        != ftrace_stub)



	adrp	x1, ftrace_graph_entry	//     || (ftrace_graph_entry

	adrp	x0, ftrace_graph_entry_stub //     != ftrace_graph_entry_stub))

	ldr	x2, [x1, #:lo12:ftrace_graph_entry]

	add	x0, x0, #:lo12:ftrace_graph_entry_stub

	cmp	x0, x2

	b.ne	ftrace_graph_caller	//     ftrace_graph_caller();

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