[ARM] Fix virtual to physical translation macro corner cases
Russell King [Thu, 12 Mar 2009 17:03:48 +0000 (17:03 +0000)]
The current use of these macros works well when the conversion is
entirely linear.  In this case, we can be assured that the following
holds true:

__va(p + s) - s = __va(p)

However, this is not always the case, especially when there is a
non-linear conversion (eg, when there is a 3.5GB hole in memory.)
In this case, if 's' is the size of the region (eg, PAGE_SIZE) and
'p' is the final page, the above is most definitely not true.

So, we must ensure that __va() and __pa() are only used with valid
kernel direct mapped RAM addresses.  This patch tweaks the code
to achieve this.

Tested-by: Charles Moschel <fred99@carolina.rr.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/dma-mapping.c
arch/arm/mm/init.c
arch/arm/mm/mmap.c

index 310e479..f1ef561 100644 (file)
@@ -490,26 +490,30 @@ core_initcall(consistent_init);
  */
 void dma_cache_maint(const void *start, size_t size, int direction)
 {
-       const void *end = start + size;
+       void (*inner_op)(const void *, const void *);
+       void (*outer_op)(unsigned long, unsigned long);
 
-       BUG_ON(!virt_addr_valid(start) || !virt_addr_valid(end - 1));
+       BUG_ON(!virt_addr_valid(start) || !virt_addr_valid(start + size - 1));
 
        switch (direction) {
        case DMA_FROM_DEVICE:           /* invalidate only */
-               dmac_inv_range(start, end);
-               outer_inv_range(__pa(start), __pa(end));
+               inner_op = dmac_inv_range;
+               outer_op = outer_inv_range;
                break;
        case DMA_TO_DEVICE:             /* writeback only */
-               dmac_clean_range(start, end);
-               outer_clean_range(__pa(start), __pa(end));
+               inner_op = dmac_clean_range;
+               outer_op = outer_clean_range;
                break;
        case DMA_BIDIRECTIONAL:         /* writeback and invalidate */
-               dmac_flush_range(start, end);
-               outer_flush_range(__pa(start), __pa(end));
+               inner_op = dmac_flush_range;
+               outer_op = outer_flush_range;
                break;
        default:
                BUG();
        }
+
+       inner_op(start, start + size);
+       outer_op(__pa(start), __pa(start) + size);
 }
 EXPORT_SYMBOL(dma_cache_maint);
 
index 34df4d9..80fd3b6 100644 (file)
@@ -382,7 +382,7 @@ void __init bootmem_init(void)
        for_each_node(node)
                bootmem_free_node(node, mi);
 
-       high_memory = __va(memend_pfn << PAGE_SHIFT);
+       high_memory = __va((memend_pfn << PAGE_SHIFT) - 1) + 1;
 
        /*
         * This doesn't seem to be used by the Linux memory manager any
index 5358fcc..f7457fe 100644 (file)
@@ -124,7 +124,7 @@ int valid_phys_addr_range(unsigned long addr, size_t size)
 {
        if (addr < PHYS_OFFSET)
                return 0;
-       if (addr + size > __pa(high_memory))
+       if (addr + size >= __pa(high_memory - 1))
                return 0;
 
        return 1;