[MIPS] Setup min_low_pfn/max_low_pfn correctly

This patch makes a better usage of these two globals.
'min_low_pfn' is now correctly setup for all configs, which
allow us to rely on it in boot memory code init.

Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 11 insertions, 12 deletions

diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index fb427dbfe71e..5257f7b42fd2 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -341,7 +341,6 @@ static int __init page_is_ram(unsigned long pagenr)
 void __init paging_init(void)
 {
         unsigned long zones_size[MAX_NR_ZONES] = { 0, };
-        unsigned long max_dma, low;
 #ifndef CONFIG_FLATMEM
         unsigned long zholes_size[MAX_NR_ZONES] = { 0, };
         unsigned long i, j, pfn;
@@ -354,19 +353,19 @@ void __init paging_init(void)
 #endif
         kmap_coherent_init();
 
-        max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
-        low = max_low_pfn;
-
 #ifdef CONFIG_ISA
-        if (low < max_dma)
-                zones_size[ZONE_DMA] = low;
-        else {
-                zones_size[ZONE_DMA] = max_dma;
-                zones_size[ZONE_NORMAL] = low - max_dma;
-        }
-#else
-        zones_size[ZONE_DMA] = low;
+        if (max_low_pfn >= MAX_DMA_PFN)
+                if (min_low_pfn >= MAX_DMA_PFN) {
+                        zones_size[ZONE_DMA] = 0;
+                        zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
+                } else {
+                        zones_size[ZONE_DMA] = MAX_DMA_PFN - min_low_pfn;
+                        zones_size[ZONE_NORMAL] = max_low_pfn - MAX_DMA_PFN;
+                }
+        else
 #endif
+        zones_size[ZONE_DMA] = max_low_pfn - min_low_pfn;
+
 #ifdef CONFIG_HIGHMEM
         zones_size[ZONE_HIGHMEM] = highend_pfn - highstart_pfn;