[PATCH 6/6] m68k: don't provide arch_dma_alloc for nommu/coldfire

Christoph Hellwig
2023-10-09T07:41:58Z

m68knommu and coldfire can't provide coherent DMA allocations at all.
Currently they simply return normal kernel memory from
dma_alloc_coherent, which is broken and breaks the API contract. Now
that the only DMA capable driver on these systems has been switched
to use explicitly non-coherent allocations we can drop this hack and
return NULL from dma_alloc_coherent.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
arch/m68k/Kconfig | 1 -
arch/m68k/kernel/dma.c | 23 -----------------------
2 files changed, 24 deletions(-)

diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 0430b8ba6b5cc6..3e318bf9504c5b 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -3,7 +3,6 @@ config M68K
bool
default y
select ARCH_32BIT_OFF_T
- select ARCH_DMA_ALLOC if !MMU || COLDFIRE
select ARCH_HAS_BINFMT_FLAT
select ARCH_HAS_CPU_FINALIZE_INIT if MMU
select ARCH_HAS_CURRENT_STACK_POINTER
diff --git a/arch/m68k/kernel/dma.c b/arch/m68k/kernel/dma.c
index 2e192a5df949bb..eb164ef1a45ebd 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