netdev - [PATCH 7/8] m68k: don't provide arch_dma

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Date: Fri, 20 Oct 2023 07:40:23 +0200
From: Christoph Hellwig <hch@....de>
To: Greg Ungerer <gerg@...ux-m68k.org>,
	iommu@...ts.linux.dev
Cc: Robin Murphy <robin.murphy@....com>,
	Marek Szyprowski <m.szyprowski@...sung.com>,
	Geert Uytterhoeven <geert@...ux-m68k.org>,
	Wei Fang <wei.fang@....com>,
	Shenwei Wang <shenwei.wang@....com>,
	Clark Wang <xiaoning.wang@....com>,
	NXP Linux Team <linux-imx@....com>,
	linux-m68k@...ts.linux-m68k.org,
	netdev@...r.kernel.org
Subject: [PATCH 7/8] m68k: don't provide arch_dma_alloc for nommu/coldfire

Coldfire cores configured with a data cache can't provide coherent
DMA allocations at all.

Instead of returning non-coherent kernel memory in this case,
return NULL and fail the allocation.

The only driver that used to rely on the previous behavior (fec) has
been switched to use non-coherent allocations for this case recently.

Signed-off-by: Christoph Hellwig <hch@....de>
Reviewed-by: Greg Ungerer <gerg@...ux-m68k.org>
Tested-by: Greg Ungerer <gerg@...ux-m68k.org>
---
 arch/m68k/kernel/dma.c | 23 -----------------------
 1 file changed, 23 deletions(-)

diff --git a/arch/m68k/kernel/dma.c b/arch/m68k/kernel/dma.c
index f83870cfa79b37..eef63d032abb53 100644
--- a/arch/m68k/kernel/dma.c
+++ b/arch/m68k/kernel/dma.c
@@ -33,29 +33,6 @@ pgprot_t pgprot_dmacoherent(pgprot_t prot)
 	}
 	return prot;
 }
-#else
-void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
-		gfp_t gfp, unsigned long attrs)
-{
-	void *ret;
-
-	if (dev == NULL || (*dev->dma_mask < 0xffffffff))
-		gfp |= GFP_DMA;
-	ret = (void *)__get_free_pages(gfp, get_order(size));
-
-	if (ret != NULL) {
-		memset(ret, 0, size);
-		*dma_handle = virt_to_phys(ret);
-	}
-	return ret;
-}
-
-void arch_dma_free(struct device *dev, size_t size, void *vaddr,
-		dma_addr_t dma_handle, unsigned long attrs)
-{
-	free_pages((unsigned long)vaddr, get_order(size));
-}
-
 #endif /* CONFIG_MMU && !CONFIG_COLDFIRE */
 
 void arch_sync_dma_for_device(phys_addr_t handle, size_t size,
-- 
2.39.2