ARM: 6938/1: fiq: Refactor {get,set}_fiq_regs() for Thumb-2

* To remove the risk of inconvenient register allocation decisions
   by the compiler, these functions are separated out as pure
   assembler.

 * The apcs frame manipulation code is not applicable for Thumb-2
   (and also not easily compatible).  Since it's not essential to
   have a full frame on these leaf assembler functions, the frame
   manipulation is removed, in the interests of simplicity.

 * Split up ldm/stm instructions to be compatible with Thumb-2,
   as well as avoiding instruction forms deprecated on >= ARMv7.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Dave Martin
2011-05-23 12:22:10 +01:00
committed by Russell King
parent 4db70f73e5
commit dc2eb928a1
4 changed files with 66 additions and 46 deletions

View File

@@ -89,47 +89,6 @@ void set_fiq_handler(void *start, unsigned int length)
flush_icache_range(0x1c, 0x1c + length);
}
/*
* Taking an interrupt in FIQ mode is death, so both these functions
* disable irqs for the duration. Note - these functions are almost
* entirely coded in assembly.
*/
void __naked set_fiq_regs(struct pt_regs *regs)
{
register unsigned long tmp;
asm volatile (
"mov ip, sp\n\
stmfd sp!, {fp, ip, lr, pc}\n\
sub fp, ip, #4\n\
mrs %0, cpsr\n\
msr cpsr_c, %2 @ select FIQ mode\n\
mov r0, r0\n\
ldmia %1, {r8 - r14}\n\
msr cpsr_c, %0 @ return to SVC mode\n\
mov r0, r0\n\
ldmfd sp, {fp, sp, pc}"
: "=&r" (tmp)
: "r" (&regs->ARM_r8), "I" (PSR_I_BIT | PSR_F_BIT | FIQ_MODE));
}
void __naked get_fiq_regs(struct pt_regs *regs)
{
register unsigned long tmp;
asm volatile (
"mov ip, sp\n\
stmfd sp!, {fp, ip, lr, pc}\n\
sub fp, ip, #4\n\
mrs %0, cpsr\n\
msr cpsr_c, %2 @ select FIQ mode\n\
mov r0, r0\n\
stmia %1, {r8 - r14}\n\
msr cpsr_c, %0 @ return to SVC mode\n\
mov r0, r0\n\
ldmfd sp, {fp, sp, pc}"
: "=&r" (tmp)
: "r" (&regs->ARM_r8), "I" (PSR_I_BIT | PSR_F_BIT | FIQ_MODE));
}
int claim_fiq(struct fiq_handler *f)
{
int ret = 0;
@@ -174,8 +133,8 @@ void disable_fiq(int fiq)
}
EXPORT_SYMBOL(set_fiq_handler);
EXPORT_SYMBOL(set_fiq_regs);
EXPORT_SYMBOL(get_fiq_regs);
EXPORT_SYMBOL(__set_fiq_regs); /* defined in fiqasm.S */
EXPORT_SYMBOL(__get_fiq_regs); /* defined in fiqasm.S */
EXPORT_SYMBOL(claim_fiq);
EXPORT_SYMBOL(release_fiq);
EXPORT_SYMBOL(enable_fiq);