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Diffstat (limited to 'arch/arc/mm/dma.c')
-rw-r--r--arch/arc/mm/dma.c28
1 files changed, 18 insertions, 10 deletions
diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
index 12cc6485b218..57706a9c6948 100644
--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c
@@ -14,8 +14,6 @@
* Cache bit off in the TLB entry.
*
* The default DMA address == Phy address which is 0x8000_0000 based.
- * A platform/device can make it zero based, by over-riding
- * plat_{dma,kernel}_addr_to_{kernel,dma}
*/
#include <linux/dma-mapping.h>
@@ -37,7 +35,7 @@ void *dma_alloc_noncoherent(struct device *dev, size_t size,
return NULL;
/* This is bus address, platform dependent */
- *dma_handle = plat_kernel_addr_to_dma(dev, paddr);
+ *dma_handle = (dma_addr_t)paddr;
return paddr;
}
@@ -46,8 +44,7 @@ EXPORT_SYMBOL(dma_alloc_noncoherent);
void dma_free_noncoherent(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle)
{
- free_pages_exact((void *)plat_dma_addr_to_kernel(dev, dma_handle),
- size);
+ free_pages_exact((void *)dma_handle, size);
}
EXPORT_SYMBOL(dma_free_noncoherent);
@@ -63,11 +60,23 @@ void *dma_alloc_coherent(struct device *dev, size_t size,
/* This is kernel Virtual address (0x7000_0000 based) */
kvaddr = ioremap_nocache((unsigned long)paddr, size);
- if (kvaddr != NULL)
- memset(kvaddr, 0, size);
+ if (kvaddr == NULL)
+ return NULL;
/* This is bus address, platform dependent */
- *dma_handle = plat_kernel_addr_to_dma(dev, paddr);
+ *dma_handle = (dma_addr_t)paddr;
+
+ /*
+ * Evict any existing L1 and/or L2 lines for the backing page
+ * in case it was used earlier as a normal "cached" page.
+ * Yeah this bit us - STAR 9000898266
+ *
+ * Although core does call flush_cache_vmap(), it gets kvaddr hence
+ * can't be used to efficiently flush L1 and/or L2 which need paddr
+ * Currently flush_cache_vmap nukes the L1 cache completely which
+ * will be optimized as a separate commit
+ */
+ dma_cache_wback_inv((unsigned long)paddr, size);
return kvaddr;
}
@@ -78,8 +87,7 @@ void dma_free_coherent(struct device *dev, size_t size, void *kvaddr,
{
iounmap((void __force __iomem *)kvaddr);
- free_pages_exact((void *)plat_dma_addr_to_kernel(dev, dma_handle),
- size);
+ free_pages_exact((void *)dma_handle, size);
}
EXPORT_SYMBOL(dma_free_coherent);