[tip:x86/dma] x86/dma/amd_gart: Look at dev->coherent_dma_mask instead of GFP_DMA

[tip-bot for Christoph Hellwig]

Commit-ID:  f3c39d51043dcee5dd4d51dffcfe9ce01a263582
Gitweb:     https://git.kernel.org/tip/f3c39d51043dcee5dd4d51dffcfe9ce01a263582
Author:     Christoph Hellwig <hch@xxxxxx>
AuthorDate: Mon, 19 Mar 2018 11:38:17 +0100
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 20 Mar 2018 10:01:57 +0100

x86/dma/amd_gart: Look at dev->coherent_dma_mask instead of GFP_DMA

We want to phase out looking at the magic GFP_DMA flag in the DMA mapping
routines, so switch the gart driver to use the dev->coherent_dma_mask
instead, which is used to select the GFP_DMA flag in the caller.

Tested-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: Joerg Roedel <joro@xxxxxxxxxx>
Cc: Jon Mason <jdmason@xxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Muli Ben-Yehuda <mulix@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20180319103826.12853-6-hch@xxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/kernel/amd_gart_64.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c
index 52e3abcf3e70..79ac6caaaabb 100644
--- a/arch/x86/kernel/amd_gart_64.c
+++ b/arch/x86/kernel/amd_gart_64.c
@@ -484,7 +484,7 @@ gart_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr,
 	unsigned long align_mask;
 	struct page *page;
 
-	if (force_iommu && !(flag & GFP_DMA)) {
+	if (force_iommu && dev->coherent_dma_mask > DMA_BIT_MASK(24)) {
 		flag &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);
 		page = alloc_pages(flag | __GFP_ZERO, get_order(size));
 		if (!page)