Switch openrisc to use the dma-direct allocator and just provide the
hooks for setting memory uncached or cached.
Signed-off-by: Christoph Hellwig <[email protected]>
---
arch/openrisc/Kconfig | 2 ++
arch/openrisc/kernel/dma.c | 55 +++++++-------------------------------
2 files changed, 12 insertions(+), 45 deletions(-)
diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
index 1928e061ff96..7e94fe37cb2f 100644
--- a/arch/openrisc/Kconfig
+++ b/arch/openrisc/Kconfig
@@ -7,6 +7,8 @@
config OPENRISC
def_bool y
select ARCH_32BIT_OFF_T
+ select ARCH_HAS_DMA_SET_UNCACHED
+ select ARCH_HAS_DMA_CLEAR_UNCACHED
select ARCH_HAS_SYNC_DMA_FOR_DEVICE
select OF
select OF_EARLY_FLATTREE
diff --git a/arch/openrisc/kernel/dma.c b/arch/openrisc/kernel/dma.c
index adec711ad39d..c152a68811dd 100644
--- a/arch/openrisc/kernel/dma.c
+++ b/arch/openrisc/kernel/dma.c
@@ -11,8 +11,6 @@
* Copyright (C) 2010-2011 Jonas Bonn <[email protected]>
*
* DMA mapping callbacks...
- * As alloc_coherent is the only DMA callback being used currently, that's
- * the only thing implemented properly. The rest need looking into...
*/
#include <linux/dma-noncoherent.h>
@@ -67,62 +65,29 @@ static const struct mm_walk_ops clear_nocache_walk_ops = {
.pte_entry = page_clear_nocache,
};
-/*
- * Alloc "coherent" memory, which for OpenRISC means simply uncached.
- *
- * This function effectively just calls __get_free_pages, sets the
- * cache-inhibit bit on those pages, and makes sure that the pages are
- * flushed out of the cache before they are used.
- *
- * If the NON_CONSISTENT attribute is set, then this function just
- * returns "normal", cachable memory.
- *
- * There are additional flags WEAK_ORDERING and WRITE_COMBINE to take
- * into consideration here, too. All current known implementations of
- * the OR1K support only strongly ordered memory accesses, so that flag
- * is being ignored for now; uncached but write-combined memory is a
- * missing feature of the OR1K.
- */
-void *
-arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
- gfp_t gfp, unsigned long attrs)
+void *arch_dma_set_uncached(void *cpu_addr, size_t size)
{
- unsigned long va;
- void *page;
-
- page = alloc_pages_exact(size, gfp | __GFP_ZERO);
- if (!page)
- return NULL;
-
- /* This gives us the real physical address of the first page. */
- *dma_handle = __pa(page);
-
- va = (unsigned long)page;
+ unsigned long va = (unsigned long)cpu_addr;
+ int error;
/*
* We need to iterate through the pages, clearing the dcache for
* them and setting the cache-inhibit bit.
*/
- if (walk_page_range(&init_mm, va, va + size, &set_nocache_walk_ops,
- NULL)) {
- free_pages_exact(page, size);
- return NULL;
- }
-
- return (void *)va;
+ error = walk_page_range(&init_mm, va, va + size, &set_nocache_walk_ops,
+ NULL);
+ if (error)
+ return ERR_PTR(error);
+ return cpu_addr;
}
-void
-arch_dma_free(struct device *dev, size_t size, void *vaddr,
- dma_addr_t dma_handle, unsigned long attrs)
+void arch_dma_clear_uncached(void *cpu_addr, size_t size)
{
- unsigned long va = (unsigned long)vaddr;
+ unsigned long va = (unsigned long)cpu_addr;
/* walk_page_range shouldn't be able to fail here */
WARN_ON(walk_page_range(&init_mm, va, va + size,
&clear_nocache_walk_ops, NULL));
-
- free_pages_exact(vaddr, size);
}
void arch_sync_dma_for_device(phys_addr_t addr, size_t size,
--
2.24.1
On Mon, Feb 24, 2020 at 11:44:45AM -0800, Christoph Hellwig wrote:
> Switch openrisc to use the dma-direct allocator and just provide the
> hooks for setting memory uncached or cached.
>
> Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Stafford Horne <[email protected]>
I also test booted this series with linux 5.5 on my OpenRISC target. There are
no issues. Note, I had an issue with patch 3/5 not cleanly applying with 'git am'
but it worked fine using just patch, I didn't get any other details.
-Stafford