csky/dma: Fixup cache_op failed when cross memory ZONEs

If the paddr and size are cross between NORMAL_ZONE and HIGHMEM_ZONE
memory range, cache_op will panic in do_page_fault with bad_area.

Optimize the code to support the range which cross memory ZONEs.

Changes for V2:
 - Revert back to postcore_initcall

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>

diff --git a/arch/csky/mm/dma-mapping.c b/arch/csky/mm/dma-mapping.c
index 80783bb71c5cb8395b3c8baee713b310af89a396..65f531d54814738890e50334cf712ad926eda3a5 100644 (file)
--- a/arch/csky/mm/dma-mapping.c
+++ b/arch/csky/mm/dma-mapping.c
@@ -20,69 +20,50 @@ static int __init atomic_pool_init(void)
 }
 postcore_initcall(atomic_pool_init);
 
-void arch_dma_prep_coherent(struct page *page, size_t size)
-{
-       if (PageHighMem(page)) {
-               unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
-
-               do {
-                       void *ptr = kmap_atomic(page);
-                       size_t _size = (size < PAGE_SIZE) ? size : PAGE_SIZE;
-
-                       memset(ptr, 0, _size);
-                       dma_wbinv_range((unsigned long)ptr,
-                                       (unsigned long)ptr + _size);
-
-                       kunmap_atomic(ptr);
-
-                       page++;
-                       size -= PAGE_SIZE;
-                       count--;
-               } while (count);
-       } else {
-               void *ptr = page_address(page);
-
-               memset(ptr, 0, size);
-               dma_wbinv_range((unsigned long)ptr, (unsigned long)ptr + size);
-       }
-}
-
 static inline void cache_op(phys_addr_t paddr, size_t size,
                            void (*fn)(unsigned long start, unsigned long end))
 {
-       struct page *page = pfn_to_page(paddr >> PAGE_SHIFT);
-       unsigned int offset = paddr & ~PAGE_MASK;
-       size_t left = size;
-       unsigned long start;
+       struct page *page    = phys_to_page(paddr);
+       void *start          = __va(page_to_phys(page));
+       unsigned long offset = offset_in_page(paddr);
+       size_t left          = size;
 
        do {
                size_t len = left;
 
+               if (offset + len > PAGE_SIZE)
+                       len = PAGE_SIZE - offset;
+
                if (PageHighMem(page)) {
-                       void *addr;
+                       start = kmap_atomic(page);
 
-                       if (offset + len > PAGE_SIZE) {
-                               if (offset >= PAGE_SIZE) {
-                                       page += offset >> PAGE_SHIFT;
-                                       offset &= ~PAGE_MASK;
-                               }
-                               len = PAGE_SIZE - offset;
-                       }
+                       fn((unsigned long)start + offset,
+                                       (unsigned long)start + offset + len);
 
-                       addr = kmap_atomic(page);
-                       start = (unsigned long)(addr + offset);
-                       fn(start, start + len);
-                       kunmap_atomic(addr);
+                       kunmap_atomic(start);
                } else {
-                       start = (unsigned long)phys_to_virt(paddr);
-                       fn(start, start + size);
+                       fn((unsigned long)start + offset,
+                                       (unsigned long)start + offset + len);
                }
                offset = 0;
+
                page++;
+               start += PAGE_SIZE;
                left -= len;
        } while (left);
 }
 
+static void dma_wbinv_set_zero_range(unsigned long start, unsigned long end)
+{
+       memset((void *)start, 0, end - start);
+       dma_wbinv_range(start, end);
+}
+
+void arch_dma_prep_coherent(struct page *page, size_t size)
+{
+       cache_op(page_to_phys(page), size, dma_wbinv_set_zero_range);
+}
+
 void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
                              size_t size, enum dma_data_direction dir)
 {