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Diffstat (limited to 'arch/powerpc/mm/mem.c')
-rw-r--r--arch/powerpc/mm/mem.c20
1 files changed, 15 insertions, 5 deletions
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index be941d382c8d..c95b7fe9f298 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -31,6 +31,7 @@
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/memremap.h>
+#include <linux/dma-direct.h>
#include <asm/pgalloc.h>
#include <asm/prom.h>
@@ -201,10 +202,10 @@ static int __init mark_nonram_nosave(void)
* everything else. GFP_DMA32 page allocations automatically fall back to
* ZONE_DMA.
*
- * By using 31-bit unconditionally, we can exploit ARCH_ZONE_DMA_BITS to
- * inform the generic DMA mapping code. 32-bit only devices (if not handled
- * by an IOMMU anyway) will take a first dip into ZONE_NORMAL and get
- * otherwise served by ZONE_DMA.
+ * By using 31-bit unconditionally, we can exploit zone_dma_bits to inform the
+ * generic DMA mapping code. 32-bit only devices (if not handled by an IOMMU
+ * anyway) will take a first dip into ZONE_NORMAL and get otherwise served by
+ * ZONE_DMA.
*/
static unsigned long max_zone_pfns[MAX_NR_ZONES];
@@ -237,9 +238,18 @@ void __init paging_init(void)
printk(KERN_DEBUG "Memory hole size: %ldMB\n",
(long int)((top_of_ram - total_ram) >> 20));
+ /*
+ * Allow 30-bit DMA for very limited Broadcom wifi chips on many
+ * powerbooks.
+ */
+ if (IS_ENABLED(CONFIG_PPC32))
+ zone_dma_bits = 30;
+ else
+ zone_dma_bits = 31;
+
#ifdef CONFIG_ZONE_DMA
max_zone_pfns[ZONE_DMA] = min(max_low_pfn,
- 1UL << (ARCH_ZONE_DMA_BITS - PAGE_SHIFT));
+ 1UL << (zone_dma_bits - PAGE_SHIFT));
#endif
max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
#ifdef CONFIG_HIGHMEM