diff options
| author | Stefan Agner <stefan@agner.ch> | 2015-06-02 20:43:24 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-06-12 21:18:48 +0100 |
| commit | 970d96f9a81b0dd83ddd8bce0e5e1ba31881c5f5 (patch) | |
| tree | ef843301ca4e6bad69a32adf2e764abad0692ed3 /arch/arm/kernel/head-nommu.S | |
| parent | 05c9ca8843cdf688275df891d512e204359717c5 (diff) | |
ARM: 8383/1: nommu: avoid deprecated source register on mov
In Thumb2 mode, the stack register r13 is deprecated if the
destination register is the program counter (r15). Similar to
head.S, head-nommu.S uses r13 to store the return address used
after configuring the CPU's CP15 register. However, since we do
not enable a MMU, there will be no address switch and it is
possible to use branch with link instruction to call
__after_proc_init.
Avoid using r13 completely by using bl to call __after_proc_init
and get rid of __secondary_switched.
Beside removing unnecessary complexity, this also fixes a
compiler warning when compiling a !MMU kernel:
Warning: Use of r13 as a source register is deprecated when r15
is the destination register.
Tested-?by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/head-nommu.S')
| -rw-r--r-- | arch/arm/kernel/head-nommu.S | 21 |
1 files changed, 8 insertions, 13 deletions
diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S index c9660167ef1a..9b8c5a113434 100644 --- a/arch/arm/kernel/head-nommu.S +++ b/arch/arm/kernel/head-nommu.S @@ -77,13 +77,13 @@ ENTRY(stext) orr r6, r6, #(1 << MPU_RSR_EN) @ Set region enabled bit bl __setup_mpu #endif - ldr r13, =__mmap_switched @ address to jump to after - @ initialising sctlr + badr lr, 1f @ return (PIC) address ldr r12, [r10, #PROCINFO_INITFUNC] add r12, r12, r10 ret r12 - 1: b __after_proc_init +1: bl __after_proc_init + b __mmap_switched ENDPROC(stext) #ifdef CONFIG_SMP @@ -106,8 +106,7 @@ ENTRY(secondary_startup) movs r10, r5 @ invalid processor? beq __error_p @ yes, error 'p' - adr r4, __secondary_data - ldmia r4, {r7, r12} + ldr r7, __secondary_data #ifdef CONFIG_ARM_MPU /* Use MPU region info supplied by __cpu_up */ @@ -115,23 +114,19 @@ ENTRY(secondary_startup) bl __setup_mpu @ Initialize the MPU #endif - badr lr, __after_proc_init @ return address - mov r13, r12 @ __secondary_switched address + badr lr, 1f @ return (PIC) address ldr r12, [r10, #PROCINFO_INITFUNC] add r12, r12, r10 ret r12 -ENDPROC(secondary_startup) - -ENTRY(__secondary_switched) +1: bl __after_proc_init ldr sp, [r7, #12] @ set up the stack pointer mov fp, #0 b secondary_start_kernel -ENDPROC(__secondary_switched) +ENDPROC(secondary_startup) .type __secondary_data, %object __secondary_data: .long secondary_data - .long __secondary_switched #endif /* CONFIG_SMP */ /* @@ -164,7 +159,7 @@ __after_proc_init: #endif mcr p15, 0, r0, c1, c0, 0 @ write control reg #endif /* CONFIG_CPU_CP15 */ - ret r13 + ret lr ENDPROC(__after_proc_init) .ltorg |