[RFC] DMA mapping error check analysis

[Shuah Khan]

I analyzed all calls to dma_map_single() and dma_map_page() in the
kernel, to see if callers check for mapping errors, before using the
returned address.

The goal of this analysis is to find drivers that currently do not 
check dma mapping errors, and fix them.

I documented the results of this analysis:

http://linuxdriverproject.org/mediawiki/index.php/DMA_Mapping_Error_Analysis

Please review and give me feedback on the analysis and the proposed
next steps.

Thanks,
-- Shuah