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-rw-r--r--arch/arc/mm/cache.c17
-rw-r--r--arch/arc/mm/dma.c49
2 files changed, 61 insertions, 5 deletions
diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index 9dbe645ee127..25c631942500 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -1038,7 +1038,7 @@ void flush_cache_mm(struct mm_struct *mm)
void flush_cache_page(struct vm_area_struct *vma, unsigned long u_vaddr,
unsigned long pfn)
{
- unsigned int paddr = pfn << PAGE_SHIFT;
+ phys_addr_t paddr = pfn << PAGE_SHIFT;
u_vaddr &= PAGE_MASK;
@@ -1058,8 +1058,9 @@ void flush_anon_page(struct vm_area_struct *vma, struct page *page,
unsigned long u_vaddr)
{
/* TBD: do we really need to clear the kernel mapping */
- __flush_dcache_page(page_address(page), u_vaddr);
- __flush_dcache_page(page_address(page), page_address(page));
+ __flush_dcache_page((phys_addr_t)page_address(page), u_vaddr);
+ __flush_dcache_page((phys_addr_t)page_address(page),
+ (phys_addr_t)page_address(page));
}
@@ -1246,6 +1247,16 @@ void __init arc_cache_init_master(void)
}
}
+ /*
+ * Check that SMP_CACHE_BYTES (and hence ARCH_DMA_MINALIGN) is larger
+ * or equal to any cache line length.
+ */
+ BUILD_BUG_ON_MSG(L1_CACHE_BYTES > SMP_CACHE_BYTES,
+ "SMP_CACHE_BYTES must be >= any cache line length");
+ if (is_isa_arcv2() && (l2_line_sz > SMP_CACHE_BYTES))
+ panic("L2 Cache line [%d] > kernel Config [%d]\n",
+ l2_line_sz, SMP_CACHE_BYTES);
+
/* Note that SLC disable not formally supported till HS 3.0 */
if (is_isa_arcv2() && l2_line_sz && !slc_enable)
arc_slc_disable();
diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
index 8c1071840979..ec47e6079f5d 100644
--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c
@@ -129,14 +129,59 @@ int arch_dma_mmap(struct device *dev, struct vm_area_struct *vma,
return ret;
}
+/*
+ * Cache operations depending on function and direction argument, inspired by
+ * https://lkml.org/lkml/2018/5/18/979
+ * "dma_sync_*_for_cpu and direction=TO_DEVICE (was Re: [PATCH 02/20]
+ * dma-mapping: provide a generic dma-noncoherent implementation)"
+ *
+ * | map == for_device | unmap == for_cpu
+ * |----------------------------------------------------------------
+ * TO_DEV | writeback writeback | none none
+ * FROM_DEV | invalidate invalidate | invalidate* invalidate*
+ * BIDIR | writeback+inv writeback+inv | invalidate invalidate
+ *
+ * [*] needed for CPU speculative prefetches
+ *
+ * NOTE: we don't check the validity of direction argument as it is done in
+ * upper layer functions (in include/linux/dma-mapping.h)
+ */
+
void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
size_t size, enum dma_data_direction dir)
{
- dma_cache_wback(paddr, size);
+ switch (dir) {
+ case DMA_TO_DEVICE:
+ dma_cache_wback(paddr, size);
+ break;
+
+ case DMA_FROM_DEVICE:
+ dma_cache_inv(paddr, size);
+ break;
+
+ case DMA_BIDIRECTIONAL:
+ dma_cache_wback_inv(paddr, size);
+ break;
+
+ default:
+ break;
+ }
}
void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
size_t size, enum dma_data_direction dir)
{
- dma_cache_inv(paddr, size);
+ switch (dir) {
+ case DMA_TO_DEVICE:
+ break;
+
+ /* FROM_DEVICE invalidate needed if speculative CPU prefetch only */
+ case DMA_FROM_DEVICE:
+ case DMA_BIDIRECTIONAL:
+ dma_cache_inv(paddr, size);
+ break;
+
+ default:
+ break;
+ }
}