Merge tag 'xtensa-20151108' of git://github.com/czankel/xtensa-linux

Pull xtensa updates from Chris Zankel:

 - fix remaining issues with noMMU cores
 - fix build for cores w/o cache or zero overhead loop options
 - fix boot of secondary cores in SMP configuration
 - add support for DMA to high memory pages
 - add dma_to_phys and phys_to_dma functions.

* tag 'xtensa-20151108' of git://github.com/czankel/xtensa-linux:
  xtensa: implement dma_to_phys and phys_to_dma
  xtensa: support DMA to high memory
  Revert "xtensa: cache inquiry and unaligned cache handling functions"
  xtensa: drop unused sections and remapped reset handlers
  xtensa: fix secondary core boot in SMP
  xtensa: add FORCE_MAX_ZONEORDER to Kconfig
  xtensa: nommu: provide defconfig for de212 on kc705
  xtensa: nommu: xtfpga: add kc705 DTS
  xtensa: add de212 core variant
  xtensa: nommu: select HAVE_FUTEX_CMPXCHG
  xtensa: nommu: fix default memory start address
  xtensa: nommu: provide correct KIO addresses
  xtensa: nommu: fix USER_RING definition
  xtensa: xtfpga: fix integer overflow in TASK_SIZE
  xtensa: fix build for configs without cache options
  xtensa: fixes for configs without loop option

1 files changed, 31 insertions, 14 deletions

diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c
index fb75ebf..cd66698 100644
--- a/arch/xtensa/kernel/pci-dma.c
+++ b/arch/xtensa/kernel/pci-dma.c
@@ -15,14 +15,15 @@
  * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
  */
 
-#include <linux/types.h>
-#include <linux/mm.h>
-#include <linux/string.h>
-#include <linux/pci.h>
 #include <linux/gfp.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
 #include <linux/module.h>
-#include <asm/io.h>
+#include <linux/pci.h>
+#include <linux/string.h>
+#include <linux/types.h>
 #include <asm/cacheflush.h>
+#include <asm/io.h>
 
 void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
 		    enum dma_data_direction dir)
@@ -47,17 +48,36 @@ void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
 }
 EXPORT_SYMBOL(dma_cache_sync);
 
+static void do_cache_op(dma_addr_t dma_handle, size_t size,
+			void (*fn)(unsigned long, unsigned long))
+{
+	unsigned long off = dma_handle & (PAGE_SIZE - 1);
+	unsigned long pfn = PFN_DOWN(dma_handle);
+	struct page *page = pfn_to_page(pfn);
+
+	if (!PageHighMem(page))
+		fn((unsigned long)bus_to_virt(dma_handle), size);
+	else
+		while (size > 0) {
+			size_t sz = min_t(size_t, size, PAGE_SIZE - off);
+			void *vaddr = kmap_atomic(page);
+
+			fn((unsigned long)vaddr + off, sz);
+			kunmap_atomic(vaddr);
+			off = 0;
+			++page;
+			size -= sz;
+		}
+}
+
 static void xtensa_sync_single_for_cpu(struct device *dev,
 				       dma_addr_t dma_handle, size_t size,
 				       enum dma_data_direction dir)
 {
-	void *vaddr;
-
 	switch (dir) {
 	case DMA_BIDIRECTIONAL:
 	case DMA_FROM_DEVICE:
-		vaddr = bus_to_virt(dma_handle);
-		__invalidate_dcache_range((unsigned long)vaddr, size);
+		do_cache_op(dma_handle, size, __invalidate_dcache_range);
 		break;
 
 	case DMA_NONE:
@@ -73,13 +93,11 @@ static void xtensa_sync_single_for_device(struct device *dev,
 					  dma_addr_t dma_handle, size_t size,
 					  enum dma_data_direction dir)
 {
-	void *vaddr;
-
 	switch (dir) {
 	case DMA_BIDIRECTIONAL:
 	case DMA_TO_DEVICE:
-		vaddr = bus_to_virt(dma_handle);
-		__flush_dcache_range((unsigned long)vaddr, size);
+		if (XCHAL_DCACHE_IS_WRITEBACK)
+			do_cache_op(dma_handle, size, __flush_dcache_range);
 		break;
 
 	case DMA_NONE:
@@ -171,7 +189,6 @@ static dma_addr_t xtensa_map_page(struct device *dev, struct page *page,
 {
 	dma_addr_t dma_handle = page_to_phys(page) + offset;
 
-	BUG_ON(PageHighMem(page));
 	xtensa_sync_single_for_device(dev, dma_handle, size, dir);
 	return dma_handle;
 }