arch/x86/arch_vm.cpp

97 static mutex sMemoryTypeLock = MUTEX_INITIALIZER("memory type ranges");
181 optimize_memory_ranges(MemoryTypeRangeList& ranges, uint32 type,
186 	MemoryTypeRangeList::Iterator it = ranges.GetIterator();
249 		// Skip the subsequent ranges we have swallowed and possible cut one
282 	// resize ranges array
284 		memory_type_range* ranges = new(std::nothrow) memory_type_range[count];
285 		if (ranges == NULL)
290 		sTemporaryRanges = ranges;
314 	// resize the temporary points/ranges arrays, if necessary
324 			// Ignore uncacheable ranges below a certain size, if requested.
350 	// Compute the effective ranges. When ranges overlap, we go with the
354 	// memory ranges with uncomparable types.
356 	memory_type_range* ranges = sTemporaryRanges;
385 			ranges[rangeCount].size = point->address - ranges[rangeCount].base;
402 			? &ranges[rangeCount - 1] : NULL;
407 			ranges[rangeCount].base = point->address;
408 			ranges[rangeCount].type = activeRange->type;
414 	TRACE_MTRR2("effective memory type ranges:\n");
417 			ranges[i].base, ranges[i].base + ranges[i].size, ranges[i].type);
421 	// Extend ranges to be more MTRR-friendly. A range is MTRR friendly, when it
423 	// ranges without this property we need more than one MTRR. We improve
427 	// equally typed ranges, if possible. There are two exceptions to the
428 	// intersection requirement: Uncached ranges may intersect with any other
430 	// uncached ranges when extending the other ranges. Write-through ranges may
431 	// intersect with write-back ranges; the resulting type will be
432 	// write-through. Hence we can ignore write-through ranges when extending
433 	// write-back ranges.
437 		rangeList.Add(&ranges[i]);
452 		// Remove uncached and write-through ranges after processing them. This
454 		// respectively write-back ranges.
462 	TRACE_MTRR2("optimized memory type ranges:\n");
464 		if (ranges[i].size > 0) {
466 				ranges[i].base, ranges[i].base + ranges[i].size,
467 				ranges[i].type);
472 	// compute the mtrrs from the ranges
477 		// skip write-back ranges -- that'll be the default type anyway
482 			if (ranges[i].size == 0 || ranges[i].type != type)
485 			if (!add_mtrrs_for_range(ranges[i].base, ranges[i].size, type))
515 					"ignoring uncacheable ranges up to size %#" B_PRIx64 ".\n",
521 		// Not enough MTRRs. Retry with less uncacheable ranges.
523 			// Ugh, even without any uncacheable ranges the available MTRRs do
699 	// set the physical memory ranges to write-back mode