Commit 7a360df9 authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

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: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarGreg Ungerer <gerg@linux-m68k.org>
Tested-by: default avatarGreg Ungerer <gerg@linux-m68k.org>
parent ffd32a92

arch/m68k/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -6,7 +6,6 @@ config M68K 
	select ARCH_HAS_BINFMT_FLAT

	select ARCH_HAS_CPU_FINALIZE_INIT if MMU

	select ARCH_HAS_CURRENT_STACK_POINTER

	select ARCH_HAS_DMA_ALLOC if M68K_NONCOHERENT_DMA && COLDFIRE

	select ARCH_HAS_DMA_PREP_COHERENT if M68K_NONCOHERENT_DMA && !COLDFIRE

	select ARCH_HAS_SYNC_DMA_FOR_DEVICE if M68K_NONCOHERENT_DMA

	select ARCH_HAVE_NMI_SAFE_CMPXCHG if RMW_INSNS

arch/m68k/kernel/dma.c

+0 −23
Original line number Diff line number Diff line
@@ -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,