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ARC: Entry Handler tweaks: Optimize away redundant IRQ_DISABLE_SAVE

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In the exception return path, for both U/K cases, intr are already
disabled (for various existing reasons). So when we drop down to
@restore_regs, we need not redo that.

There was subtle issue - when intr were NOT being disabled for
ret-to-kernel-but-no-preemption case - now fixed by moving the
IRQ_DISABLE further up in @resume_kernel_mode.

So what do we gain:

* Shaves off a few insn in return path.

* Eliminates the need for IRQ_DISABLE_SAVE assembler macro for ARCv2
  hence allows for entry code sharing.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This commit is contained in:
Vineet Gupta
2013-07-09 17:06:40 +05:30
parent 37f3ac498c
commit fce16bc35a
2 changed files with 5 additions and 12 deletions
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7
arch/arc/include/asm/irqflags.h
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@@ -157,13 +157,6 @@ static inline void arch_unmask_irq(unsigned int irq)
flag \scratch
.endm
.macro IRQ_DISABLE_SAVE scratch, save
lr \scratch, [status32]
mov \save, \scratch /* Make a copy */
bic \scratch, \scratch, (STATUS_E1_MASK | STATUS_E2_MASK)
flag \scratch
.endm
.macro IRQ_ENABLE scratch
lr \scratch, [status32]
or \scratch, \scratch, (STATUS_E1_MASK | STATUS_E2_MASK)