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s390/maccess: reduce stnsm instructions
When fixing the DAT off bug ("s390: fix DAT off memory access, e.g. on kdump") both Christian and I missed that we can save an additional stnsm instruction. This saves us a couple of cycles which could improve the speed of memcpy_real. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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1 changed files with 6 additions and 4 deletions
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@ -93,15 +93,17 @@ static int __memcpy_real(void *dest, void *src, size_t count)
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*/
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int memcpy_real(void *dest, void *src, size_t count)
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{
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int irqs_disabled, rc;
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unsigned long flags;
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int rc;
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if (!count)
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return 0;
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local_irq_save(flags);
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__arch_local_irq_stnsm(0xfbUL);
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flags = __arch_local_irq_stnsm(0xf8UL);
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irqs_disabled = arch_irqs_disabled_flags(flags);
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if (!irqs_disabled)
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trace_hardirqs_off();
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rc = __memcpy_real(dest, src, count);
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if (!arch_irqs_disabled_flags(flags))
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if (!irqs_disabled)
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trace_hardirqs_on();
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__arch_local_irq_ssm(flags);
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return rc;
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