ARM: mvebu: use arm_coherent_dma_ops and re-enable hardware I/O coherency

Now that we have enabled automatic I/O synchronization barriers, we no
longer need any explicit barriers. We can therefore simplify
arch/arm/mach-mvebu/coherency.c by using the existing
arm_coherent_dma_ops instead of our custom mvebu_hwcc_dma_ops, and
re-enable hardware I/O coherency support.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
[Andrew Lunn <andrew@lunn.ch>: Remove forgotten comment]
Signed-off-by: Andrew Lunn <andrew@lunn.ch>

diff --git a/arch/arm/mach-mvebu/coherency.c b/arch/arm/mach-mvebu/coherency.c
index caa21e9b8cd9819de5ff0c0e505a8a937940dfae..440799ba664a18e399c4184fe974a71237a89bd4 100644 (file)
--- a/arch/arm/mach-mvebu/coherency.c
+++ b/arch/arm/mach-mvebu/coherency.c
@@ -33,6 +33,7 @@
 #include <asm/smp_plat.h>
 #include <asm/cacheflush.h>
 #include <asm/mach/map.h>
+#include <asm/dma-mapping.h>
 #include "coherency.h"
 #include "mvebu-soc-id.h"
 
@@ -76,54 +77,6 @@ int set_cpu_coherent(void)
        return ll_enable_coherency();
 }
 
-static inline void mvebu_hwcc_sync_io_barrier(void)
-{
-       writel(0x1, coherency_cpu_base + IO_SYNC_BARRIER_CTL_OFFSET);
-       while (readl(coherency_cpu_base + IO_SYNC_BARRIER_CTL_OFFSET) & 0x1);
-}
-
-static dma_addr_t mvebu_hwcc_dma_map_page(struct device *dev, struct page *page,
-                                 unsigned long offset, size_t size,
-                                 enum dma_data_direction dir,
-                                 struct dma_attrs *attrs)
-{
-       if (dir != DMA_TO_DEVICE)
-               mvebu_hwcc_sync_io_barrier();
-       return pfn_to_dma(dev, page_to_pfn(page)) + offset;
-}
-
-
-static void mvebu_hwcc_dma_unmap_page(struct device *dev, dma_addr_t dma_handle,
-                             size_t size, enum dma_data_direction dir,
-                             struct dma_attrs *attrs)
-{
-       if (dir != DMA_TO_DEVICE)
-               mvebu_hwcc_sync_io_barrier();
-}
-
-static void mvebu_hwcc_dma_sync(struct device *dev, dma_addr_t dma_handle,
-                       size_t size, enum dma_data_direction dir)
-{
-       if (dir != DMA_TO_DEVICE)
-               mvebu_hwcc_sync_io_barrier();
-}
-
-static struct dma_map_ops mvebu_hwcc_dma_ops = {
-       .alloc                  = arm_dma_alloc,
-       .free                   = arm_dma_free,
-       .mmap                   = arm_dma_mmap,
-       .map_page               = mvebu_hwcc_dma_map_page,
-       .unmap_page             = mvebu_hwcc_dma_unmap_page,
-       .get_sgtable            = arm_dma_get_sgtable,
-       .map_sg                 = arm_dma_map_sg,
-       .unmap_sg               = arm_dma_unmap_sg,
-       .sync_single_for_cpu    = mvebu_hwcc_dma_sync,
-       .sync_single_for_device = mvebu_hwcc_dma_sync,
-       .sync_sg_for_cpu        = arm_dma_sync_sg_for_cpu,
-       .sync_sg_for_device     = arm_dma_sync_sg_for_device,
-       .set_dma_mask           = arm_dma_set_mask,
-};
-
 static int mvebu_hwcc_notifier(struct notifier_block *nb,
                               unsigned long event, void *__dev)
 {
@@ -131,7 +84,7 @@ static int mvebu_hwcc_notifier(struct notifier_block *nb,
 
        if (event != BUS_NOTIFY_ADD_DEVICE)
                return NOTIFY_DONE;
-       set_dma_ops(dev, &mvebu_hwcc_dma_ops);
+       set_dma_ops(dev, &arm_coherent_dma_ops);
 
        return NOTIFY_OK;
 }
@@ -246,14 +199,9 @@ static int coherency_type(void)
        return type;
 }
 
-/*
- * As a precaution, we currently completely disable hardware I/O
- * coherency, until enough testing is done with automatic I/O
- * synchronization barriers to validate that it is a proper solution.
- */
 int coherency_available(void)
 {
-       return false;
+       return coherency_type() != COHERENCY_FABRIC_TYPE_NONE;
 }
 
 int __init coherency_init(void)