cns3xxx: add experimental 3.18 support

[15.05/openwrt.git] / target / linux / cns3xxx / patches-3.18 / 010-arm_introduce-dma-fiq-irq-broadcast.patch

diff --git a/target/linux/cns3xxx/patches-3.18/010-arm_introduce-dma-fiq-irq-broadcast.patch b/target/linux/cns3xxx/patches-3.18/010-arm_introduce-dma-fiq-irq-broadcast.patch
new file mode 100644 (file)
index 0000000..dd02323
--- /dev/null
+++ b/target/linux/cns3xxx/patches-3.18/010-arm_introduce-dma-fiq-irq-broadcast.patch
@@ -0,0 +1,64 @@
+--- a/arch/arm/include/asm/glue-cache.h
++++ b/arch/arm/include/asm/glue-cache.h
+@@ -156,11 +156,19 @@ static inline void nop_dma_unmap_area(co
+ #define __cpuc_flush_user_range               __glue(_CACHE,_flush_user_cache_range)
+ #define __cpuc_coherent_kern_range    __glue(_CACHE,_coherent_kern_range)
+ #define __cpuc_coherent_user_range    __glue(_CACHE,_coherent_user_range)
++#ifndef CONFIG_DMA_CACHE_FIQ_BROADCAST
+ #define __cpuc_flush_dcache_area      __glue(_CACHE,_flush_kern_dcache_area)
+ 
+ #define dmac_map_area                 __glue(_CACHE,_dma_map_area)
+ #define dmac_unmap_area                       __glue(_CACHE,_dma_unmap_area)
+ #define dmac_flush_range              __glue(_CACHE,_dma_flush_range)
++#else
++#define __cpuc_flush_dcache_area      __glue(fiq,_flush_kern_dcache_area)
++
++#define dmac_map_area                 __glue(fiq,_dma_map_area)
++#define dmac_unmap_area                       __glue(fiq,_dma_unmap_area)
++#define dmac_flush_range              __glue(fiq,_dma_flush_range)
++#endif /* CONFIG_DMA_CACHE_FIQ_BROADCAST */
+ #endif
+ 
+ #endif
+--- a/arch/arm/mm/Kconfig
++++ b/arch/arm/mm/Kconfig
+@@ -844,6 +844,17 @@ config DMA_CACHE_RWFO
+         in hardware, other workarounds are needed (e.g. cache
+         maintenance broadcasting in software via FIQ).
+ 
++config DMA_CACHE_FIQ_BROADCAST
++      bool "Enable fiq broadcast DMA cache maintenance"
++      depends on CPU_V6K && SMP
++      select FIQ
++      help
++        The Snoop Control Unit on ARM11MPCore does not detect the
++        cache maintenance operations and the dma_{map,unmap}_area()
++        functions may leave stale cache entries on other CPUs. By
++        enabling this option, fiq broadcast in the ARMv6
++        DMA cache maintenance functions is performed.
++
+ config OUTER_CACHE
+       bool
+ 
+--- a/arch/arm/mm/flush.c
++++ b/arch/arm/mm/flush.c
+@@ -304,6 +304,7 @@ void __sync_icache_dcache(pte_t pteval)
+ void flush_dcache_page(struct page *page)
+ {
+       struct address_space *mapping;
++      bool skip_broadcast = true;
+ 
+       /*
+        * The zero page is never written to, so never has any dirty
+@@ -314,7 +315,10 @@ void flush_dcache_page(struct page *page
+ 
+       mapping = page_mapping(page);
+ 
+-      if (!cache_ops_need_broadcast() &&
++#ifndef CONFIG_DMA_CACHE_FIQ_BROADCAST
++      skip_broadcast = !cache_ops_need_broadcast();
++#endif
++      if (skip_broadcast &&
+           mapping && !page_mapped(page))
+               clear_bit(PG_dcache_clean, &page->flags);
+       else {