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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: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Ard Biesheuvel 2014-11-07 14:12:33 +00:00 committed by Will Deacon
parent 80708677fa
commit f1ba46ee78
1 changed files with 10 additions and 9 deletions
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19
arch/arm64/kernel/entry-ftrace.S
View File

@ -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
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)
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_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();