Replace the code that sets up uncached PTEs with the generic vmap based
remapping code. It also provides an atomic pool for allocations from
non-blocking context, which we not properly supported by the existing
arc code.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
arch/arc/Kconfig | 2 ++
arch/arc/mm/dma.c | 62 ++++++++---------------------------------------
2 files changed, 12 insertions(+), 52 deletions(-)
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 23e063df5d2c..cdad7d30ff1d 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -10,6 +10,7 @@ config ARC
def_bool y
select ARC_TIMERS
select ARCH_HAS_DMA_COHERENT_TO_PFN
+ select ARCH_HAS_DMA_PREP_COHERENT
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_SETUP_DMA_OPS
select ARCH_HAS_SYNC_DMA_FOR_CPU
@@ -19,6 +20,7 @@ config ARC
select BUILDTIME_EXTABLE_SORT
select CLONE_BACKWARDS
select COMMON_CLK
+ select DMA_DIRECT_REMAP
select GENERIC_ATOMIC64 if !ISA_ARCV2 || !(ARC_HAS_LL64 && ARC_HAS_LLSC)
select GENERIC_CLOCKEVENTS
select GENERIC_FIND_FIRST_BIT
diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
index 9832928f896d..0fa850709fac 100644
--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c
@@ -11,46 +11,15 @@
#include <asm/cacheflush.h>
/*
- * ARCH specific callbacks for generic noncoherent DMA ops (dma/noncoherent.c)
+ * ARCH specific callbacks for generic noncoherent DMA ops
* - hardware IOC not available (or "dma-coherent" not set for device in DT)
* - But still handle both coherent and non-coherent requests from caller
*
* For DMA coherent hardware (IOC) generic code suffices
*/
-void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
- gfp_t gfp, unsigned long attrs)
-{
- unsigned long order = get_order(size);
- struct page *page;
- phys_addr_t paddr;
- void *kvaddr;
-
- /*
- * __GFP_HIGHMEM flag is cleared by upper layer functions
- * (in include/linux/dma-mapping.h) so we should never get a
- * __GFP_HIGHMEM here.
- */
- BUG_ON(gfp & __GFP_HIGHMEM);
-
- page = alloc_pages(gfp | __GFP_ZERO, order);
- if (!page)
- return NULL;
-
- /* This is linear addr (0x8000_0000 based) */
- paddr = page_to_phys(page);
-
- *dma_handle = paddr;
-
- /*
- * A coherent buffer needs MMU mapping to enforce non-cachability.
- * kvaddr is kernel Virtual address (0x7000_0000 based).
- */
- kvaddr = ioremap_nocache(paddr, size);
- if (kvaddr == NULL) {
- __free_pages(page, order);
- return NULL;
- }
+void arch_dma_prep_coherent(struct page *page, size_t size)
+{
/*
* Evict any existing L1 and/or L2 lines for the backing page
* in case it was used earlier as a normal "cached" page.
@@ -61,24 +30,7 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
* Currently flush_cache_vmap nukes the L1 cache completely which
* will be optimized as a separate commit
*/
- dma_cache_wback_inv(paddr, size);
- return kvaddr;
-}
-
-void arch_dma_free(struct device *dev, size_t size, void *vaddr,
- dma_addr_t dma_handle, unsigned long attrs)
-{
- phys_addr_t paddr = dma_handle;
- struct page *page = virt_to_page(paddr);
-
- iounmap((void __force __iomem *)vaddr);
- __free_pages(page, get_order(size));
-}
-
-long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr,
- dma_addr_t dma_addr)
-{
- return __phys_to_pfn(dma_addr);
+ dma_cache_wback_inv(page_to_phys(page), size);
}
/*
@@ -155,3 +107,9 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
dev_info(dev, "use %sncoherent DMA ops\n",
dev->dma_coherent ? "" : "non");
}
+
+static int __init atomic_pool_init(void)
+{
+ return dma_atomic_pool_init(GFP_KERNEL, pgprot_noncached(PAGE_KERNEL));
+}
+postcore_initcall(atomic_pool_init);
--
2.20.1
