Make swiotlb_bounce test each page for highness rather than relying on
CONFIG_HIGHMEM, and a couple of other cleanups.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
---
 lib/swiotlb.c | 61 +++++++++++++++++++++++++++++----------------------------
 1 file changed, 32 insertions(+), 29 deletions(-)
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -25,6 +25,7 @@
 #include <linux/swiotlb.h>
 #include <linux/string.h>
 #include <linux/swiotlb.h>
+#include <linux/pfn.h>
 #include <linux/types.h>
 #include <linux/ctype.h>
 #include <linux/highmem.h>
@@ -330,40 +331,42 @@
 /*
 * Bounce: copy the swiotlb buffer back to the original dma location
 */
-void swiotlb_bounce(phys_addr_t phys, char *dma_addr, size_t size,
- enum dma_data_direction dir)
+static void swiotlb_bounce(phys_addr_t phys, char *dma_addr, size_t size,
+ enum dma_data_direction dir)
 {
-#ifdef CONFIG_HIGHMEM
- /* The buffer may not have a mapping. Map it in and copy */
- unsigned int offset = ((unsigned long)phys &
- ((1 << PAGE_SHIFT) - 1));
- char *buffer;
- unsigned int sz = 0;
- unsigned long flags;
+ unsigned long pfn = PFN_DOWN(phys);
 
- while (size) {
- sz = ((PAGE_SIZE - offset) > size) ? size :
- PAGE_SIZE - offset;
- local_irq_save(flags);
- buffer = kmap_atomic(pfn_to_page(phys >> PAGE_SHIFT),
- KM_BOUNCE_READ);
+ if (PageHighMem(pfn_to_page(pfn))) {
+ /* The buffer does not have a mapping. Map it in and copy */
+ unsigned int offset = phys & ~PAGE_MASK;
+ char *buffer;
+ unsigned int sz = 0;
+ unsigned long flags;
+
+ while (size) {
+ sz = min(PAGE_SIZE - offset, size);
+
+ local_irq_save(flags);
+ buffer = kmap_atomic(pfn_to_page(pfn),
+ KM_BOUNCE_READ);
+ if (dir == DMA_TO_DEVICE)
+ memcpy(dma_addr, buffer + offset, sz);
+ else
+ memcpy(buffer + offset, dma_addr, sz);
+ kunmap_atomic(buffer, KM_BOUNCE_READ);
+ local_irq_restore(flags);
+
+ size -= sz;
+ pfn++;
+ dma_addr += sz;
+ offset = 0;
+ }
+ } else {
 if (dir == DMA_TO_DEVICE)
- memcpy(dma_addr, buffer + offset, sz);
+ memcpy(dma_addr, phys_to_virt(phys), size);
 else
- memcpy(buffer + offset, dma_addr, sz);
- kunmap_atomic(buffer, KM_BOUNCE_READ);
- local_irq_restore(flags);
- size -= sz;
- phys += sz;
- dma_addr += sz;
- offset = 0;
+ memcpy(phys_to_virt(phys), dma_addr, size);
 }
-#else
- if (dir == DMA_TO_DEVICE)
- memcpy(dma_addr, phys_to_virt(phys), size);
- else
- memcpy(phys_to_virt(phys), dma_addr, size);
-#endif
 }
 
 /*
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