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2009-01-30MIPS: IP27: Switch from DMA_IP27 to DMA_COHERENTRalf Baechle1-1/+1
The special IP27 DMA code selected by DMA_IP27 has been removed a while ago turning DMA_IP27 into almost a nop. Also fixup the broken logic of its last users memcpy.S and memcpy-inatomic.s. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-01-29[MIPS] Eleminate local symbols from the symbol table.Ralf Baechle1-58/+58
These symbols appear in oprofile output, stacktraces and similar but only make the output harder to read. Many identical symbol names such as "both_aligned" were also being used in multiple source files making it impossible to see which file actually was meant. So let's get rid of them. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-01-29[MIPS] R4000/R4400 daddiu erratum workaroundMaciej W. Rozycki1-5/+20
This complements the generic R4000/R4400 errata workaround code and adds bits for the daddiu problem. In most places it just modifies handwritten assembly code so that the assembler is allowed to use a temporary register as daddiu may now be treated as a macro that expands to a sequence of li and daddu. It is the AT register or, where AT is unavailable or used explicitly for another purpose, an explicitly-named register is selected, using the .set at=<reg> feature added recently to gas. This feature is only used if CONFIG_CPU_DADDI_WORKAROUNDS has been set, so if the workaround remains disabled, the required version of binutils stays unchanged. Similarly, daddiu instructions put in branch delay slots in noreorder fragments are now taken out of them and the assembler is allowed to reorder them itself as possible (which it does making the whole idea of scheduling them into delay slots manually questionable). Also in the very few places where such a simple conversion was not possible, a handcoded longer sequence is implemented. Other than that there are changes to code responsible for building the TLB fault and page clear/copy handlers to avoid daddiu as appropriate. These are only effective if the erratum is verified to be present at the run time. Finally there is a trivial update to __delay(), because it uses daddiu in a branch delay slot. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-02-20[MIPS] Fixup copy_from_user_inatomicRalf Baechle1-0/+436
From the 01408c4939479ec46c15aa7ef6e2406be50eeeca log message: The problem is that when we write to a file, the copy from userspace to pagecache is first done with preemption disabled, so if the source address is not immediately available the copy fails *and* *zeros* *the* *destination*. This is a problem because a concurrent read (which admittedly is an odd thing to do) might see zeros rather that was there before the write, or what was there after, or some mixture of the two (any of these being a reasonable thing to see). If the copy did fail, it will immediately be retried with preemption re-enabled so any transient problem with accessing the source won't cause an error. The first copying does not need to zero any uncopied bytes, and doing so causes the problem. It uses copy_from_user_atomic rather than copy_from_user so the simple expedient is to change copy_from_user_atomic to *not* zero out bytes on failure. < --- end cite --- > This patch finally implements at least a not so pretty solution by duplicating the relevant part of __copy_user. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>