Hi Christoph,
On Tue, Jun 25, 2019 at 11:01 AM Christoph Hellwig <hch@xxxxxx> wrote:
This switche to using common code for the DMA allocations, including
switches m68k
potential use of the CMA allocator if configure. Also add a
configured
comment where the existing behavior seems to be lacking.
Switching to the generic code enables DMA allocations from atomic
context, which is required by the DMA API documentation, and also
adds various other minor features drivers start relying upon. It
also makes sure we have on tested code base for all architectures
a tested code base
that require uncached pte bits for coherent DMA allocations.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Thanks, applying and queueing for v5.3.
--- a/arch/m68k/kernel/dma.c
+++ b/arch/m68k/kernel/dma.c
@@ -18,57 +18,20 @@
#include <asm/pgalloc.h>
#if defined(CONFIG_MMU) && !defined(CONFIG_COLDFIRE)
-
-void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
- gfp_t flag, unsigned long attrs)
+pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot,
+ unsigned long attrs)
{
- struct page *page, **map;
- pgprot_t pgprot;
- void *addr;
- int i, order;
-
- pr_debug("dma_alloc_coherent: %d,%x\n", size, flag);
-
- size = PAGE_ALIGN(size);
- order = get_order(size);
-
- page = alloc_pages(flag | __GFP_ZERO, order);
- if (!page)
- return NULL;
-
- *handle = page_to_phys(page);
- map = kmalloc(sizeof(struct page *) << order, flag & ~__GFP_DMA);
- if (!map) {
- __free_pages(page, order);
- return NULL;
+ /*
+ * XXX: this doesn't seem to handle the sun3 MMU at all.
Correct. This file is not compiled on Sun-3, which selects NO_DMA, so
I'll drop the comment while applying.
+ */
+ if (CPU_IS_040_OR_060) {
+ pgprot_val(prot) &= ~_PAGE_CACHE040;
+ pgprot_val(prot) |= _PAGE_GLOBAL040 | _PAGE_NOCACHE_S;
+ } else {
+ pgprot_val(prot) |= _PAGE_NOCACHE030;
}
- split_page(page, order);
-
- order = 1 << order;
- size >>= PAGE_SHIFT;
- map[0] = page;
- for (i = 1; i < size; i++)
- map[i] = page + i;
- for (; i < order; i++)
- __free_page(page + i);
- pgprot = __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY);
- if (CPU_IS_040_OR_060)
- pgprot_val(pgprot) |= _PAGE_GLOBAL040 | _PAGE_NOCACHE_S;
- else
- pgprot_val(pgprot) |= _PAGE_NOCACHE030;
- addr = vmap(map, size, VM_MAP, pgprot);
- kfree(map);
-
- return addr;
+ return prot;
}
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
