Re: [PATCH] PPC40x: Limit Allocable RAM During Early Mapping
From: Grant Erickson <hidden>
Date: 2008-10-30 14:33:56
From: Grant Erickson <hidden>
Date: 2008-10-30 14:33:56
On 10/30/08 7:03 AM, Josh Boyer wrote:
On Wed, 29 Oct 2008 14:41:14 -0700 Grant Erickson [off-list ref] wrote:quoted
If the size of RAM is not an exact power of two, we may not have covered RAM in its entirety with large 16 and 4 MiB pages. Consequently, restrict the top end of RAM currently allocable by updating '__initial_memory_limit_addr' so that calls to the LMB to allocate PTEs for "tail" coverage with normal-sized pages (or other reasons) do not attempt to allocate outside the allowed range.Nice catch. I was looking to see if 44x had the same problem, but I don't think it does because we simply over-map DRAM there. Does that seem correct to you, or am I missing something on 44x that would cause this same problem?
Josh, Because I do not have 44x hardware to validate against and because this particular fix was localized to the 40x path, I did not take the time to walk through the 44x path. Regards, Grant