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/* SPDX-License-Identifier: BSD-2-Clause */
/*
* Copyright (c) 2016, Linaro Limited
*/
#include <asm.S>
#ifdef CFG_TA_GPROF_SUPPORT
/*
* Convert return address to call site address by subtracting the size of the
* mcount call instruction (blx __gnu_mcount_nc).
*/
.macro mcount_adj_pc rd, rn
bic \rd, \rn, #1 /* Clear thumb bit if present */
sub \rd, \rd, #4
.endm
/*
* With the -pg option, GCC (4.4+) inserts a call to __gnu_mcount_nc into
* every function prologue.
* The caller of the instrumented function can be determined from the lr value
* stored on the top of the stack. The callee, i.e. the instrumented function
* itself, is determined from the current value of lr. Then we call:
* void __mcount_internal(void *frompc, void *selfpc);
*
* __gnu_mcount_nc is defined and set to the value of this function by the
* TA linker script, only if__gnu_mcount_nc is referenced
*/
FUNC __utee_mcount, :
stmdb sp!, {r0-r3, lr}
ldr r0, [sp, #20] /* lr of instrumented func */
mcount_adj_pc r0, r0
mcount_adj_pc r1, lr /* instrumented func */
bl __mcount_internal
ldmia sp!, {r0-r3, ip, lr}
bx ip
END_FUNC __utee_mcount
#else /* !CFG_TA_GPROF_SUPPORT */
/*
* The TA linker script always references __utee_mcount so provide a version
* that just pops one register (lr) off the stack, since that's the ABI we must
* follow.
*/
.weak __utee_mcount
FUNC __utee_mcount, :
push {lr}
pop {ip, lr}
bx ip
END_FUNC __utee_mcount
#endif /* CFG_TA_GPROF_SUPPORT */
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