On 12/8/2015 1:18 PM, Qais Yousef wrote:
Recent changes to how GFP_ATOMIC is defined seems to have broken the condition to use mips_alloc_from_contiguous() in mips_dma_alloc_coherent(). I couldn't bottom out the exact change but I think it's this one d0164adc89f6 (mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd) From what I see GFP_ATOMIC has multiple bits set and the check for !(gfp & GFP_ATOMIC) isn't enough. To verify if the flag is atomic we need to make sure that (gfp & GFP_ATOMIC) == GFP_ATOMIC to verify that all bits rquired to
Required.
satisfy GFP_ATOMIC condition are set. Signed-off-by: Qais Yousef <qais.yousef@xxxxxxxxxx> --- arch/mips/mm/dma-default.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c index d8117be729a2..d6b8a1445a3a 100644 --- a/arch/mips/mm/dma-default.c +++ b/arch/mips/mm/dma-default.c @@ -145,7 +145,7 @@ static void *mips_dma_alloc_coherent(struct device *dev, size_t size, gfp = massage_gfp_flags(dev, gfp); - if (IS_ENABLED(CONFIG_DMA_CMA) && !(gfp & GFP_ATOMIC)) + if (IS_ENABLED(CONFIG_DMA_CMA) && ((gfp & GFP_ATOMIC) != GFP_ATOMIC))
() around != not necessary. [...] MBR, Sergei
