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SubjectRe: [PATCH 3/5] x86: Only direct map addresses that are marked as E820_RAM
On 08/24/2012 04:55 PM, Jacob Shin wrote:
> +
> + for (i = 0; i < e820.nr_map; i++) {
> + struct e820entry *ei = &e820.map[i];
> + u64 start = ei->addr;
> + u64 end = ei->addr + ei->size;
> +
> + /* we only map E820_RAM */
> + if (ei->type != E820_RAM)
> + continue;
> +
> + if (end <= ISA_END_ADDRESS)
> + continue;
> +
> + if (start <= ISA_END_ADDRESS)
> + start = 0;
> +#ifdef CONFIG_X86_32
> + /* on 32 bit, we only map up to max_low_pfn */
> + if ((start >> PAGE_SHIFT) >= max_low_pfn)
> + continue;
> +
> + if ((end >> PAGE_SHIFT) > max_low_pfn)
> + end = max_low_pfn << PAGE_SHIFT;
> +#endif
> + /* the ISA range is always mapped regardless of holes */
> + if (!pfn_range_is_mapped(0, ISA_END_ADDRESS << PAGE_SHIFT) &&
> + start != 0)
> + init_memory_mapping(0, ISA_END_ADDRESS);
> +
> + init_memory_mapping(start, end);
> + }
> +

The ISA range mapping doesn't really make sense *inside* the loop, no?
It seems you could do that before you enter the loop and then simply have:

+ if (end <= ISA_END_ADDRESS)
+ continue;
+
+ if (start <= ISA_END_ADDRESS)
+ start = ISA_END_ADDRESS;

... no?

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.



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