From: David S. Miller <davem@sunset.davemloft.net>
Date: Wed, 8 Mar 2006 23:57:03 +0000 (-0800)
Subject: [SPARC64]: Fix 32-bit truncation which broke sparsemem.
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=17b0e199a10184d8c5bbbd79a4cee993bb1fb257;p=linux-beck.git

[SPARC64]: Fix 32-bit truncation which broke sparsemem.

The page->flags manipulations done by the D-cache dirty
state tracking was broken because the constants were not
marked with "UL" to make them 64-bit, which means we were
clobbering the upper 32-bits of page->flags all the time.

This doesn't jive well with sparsemem which stores the
section and indexing information in the top 32-bits of
page->flags.

This is yet another sparc64 bug which has been with us
forever.

While we're here, tidy up some things in bootmem_init()
and paginig_init():

1) Pass min_low_pfn to init_bootmem_node(), it's identical
   to (phys_base >> PAGE_SHIFT) but we should use consistent
   with the variable names we print in CONFIG_BOOTMEM_DEBUG

2) max_mapnr, although no longer used, was being set
   inaccurately, we shouldn't subtract pfn_base any more.

3) All the games with phys_base in the zones_*[] arrays
   we pass to free_area_init_node() are no longer necessary.

Thanks to Josh Grebe and Fabbione for the bug reports
and testing.  Fix also verified locally on an SB2500
which had a memory layout that triggered the same problem.

Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/arch/sparc64/mm/init.c b/arch/sparc64/mm/init.c
index 5f67b53b3a5b..b40f6477dea0 100644
--- a/arch/sparc64/mm/init.c
+++ b/arch/sparc64/mm/init.c
@@ -205,8 +205,8 @@ inline void flush_dcache_page_impl(struct page *page)
 }
 
 #define PG_dcache_dirty		PG_arch_1
-#define PG_dcache_cpu_shift	24
-#define PG_dcache_cpu_mask	(256 - 1)
+#define PG_dcache_cpu_shift	24UL
+#define PG_dcache_cpu_mask	(256UL - 1UL)
 
 #if NR_CPUS > 256
 #error D-cache dirty tracking and thread_info->cpu need fixing for > 256 cpus
@@ -901,8 +901,7 @@ static unsigned long __init bootmem_init(unsigned long *pages_avail,
 		    min_low_pfn, bootmap_pfn, max_low_pfn);
 #endif
 	bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap_pfn,
-					 (phys_base >> PAGE_SHIFT),
-					 end_pfn);
+					 min_low_pfn, end_pfn);
 
 	/* Now register the available physical memory with the
 	 * allocator.
@@ -1311,25 +1310,24 @@ void __init paging_init(void)
 	pages_avail = 0;
 	last_valid_pfn = end_pfn = bootmem_init(&pages_avail, phys_base);
 
-	max_mapnr = last_valid_pfn - (phys_base >> PAGE_SHIFT);
+	max_mapnr = last_valid_pfn;
 
 	kernel_physical_mapping_init();
 
 	{
 		unsigned long zones_size[MAX_NR_ZONES];
 		unsigned long zholes_size[MAX_NR_ZONES];
-		unsigned long npages;
 		int znum;
 
 		for (znum = 0; znum < MAX_NR_ZONES; znum++)
 			zones_size[znum] = zholes_size[znum] = 0;
 
-		npages = end_pfn - (phys_base >> PAGE_SHIFT);
-		zones_size[ZONE_DMA] = npages;
-		zholes_size[ZONE_DMA] = npages - pages_avail;
+		zones_size[ZONE_DMA] = end_pfn;
+		zholes_size[ZONE_DMA] = end_pfn - pages_avail;
 
 		free_area_init_node(0, &contig_page_data, zones_size,
-				    phys_base >> PAGE_SHIFT, zholes_size);
+				    __pa(PAGE_OFFSET) >> PAGE_SHIFT,
+				    zholes_size);
 	}
 
 	device_scan();