Linux ARM 5/16

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Summary

Linux ARM : Add linux_support.s that contains futex implementation

[andrew]

It looks like these should all be atomic operations. If so the flow should be:

1: ldrex old, [addr]
   operation
   strex res, new, [addr]
   cmp res, #0
   bne 1b

[soutade_gmail.com]

In D6762#142437, @andrew wrote:

It looks like these should all be atomic operations. If so the flow should be:

1: ldrex old, [addr]
   operation
   strex res, new, [addr]
   cmp res, #0
   bne 1b

Don't understand what is exactly the problem you point to.

[andrew]

sys/arm/linux/linux_support.s

84

There is a ldrex here, but no strex. These should be in pairs with the needed operation between the two. See sys/arm/include/atomic-v6.h as an example.

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Rework all functions with right use of ldrex and strex

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Overtaken by D7970 .. D7978