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Commit 5bf65b9b authored by Yinghai Lu's avatar Yinghai Lu Committed by H. Peter Anvin
Browse files

x86, mtrr: Fix sorting of mtrr after subtracting 



In some cases we can coalesce MTRR entries after cleanup; this may
allow us to have more entries.  As such, introduce clean_sort_range to
to sort and coaelsce the MTRR entries.

Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
LKML-Reference: <4B0BB9A3.5020908@kernel.org>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent b24c2a92

arch/x86/kernel/cpu/mtrr/cleanup.c

+40 −9
Original line number Diff line number Diff line
@@ -170,6 +170,41 @@ static int __init cmp_range(const void *x1, const void *x2) 
	return start1 - start2;

}



static int __init clean_sort_range(struct res_range *range, int az)

{

	int i, j, k = az - 1, nr_range = 0;



	for (i = 0; i < k; i++) {

		if (range[i].end)

			continue;

		for (j = k; j > i; j--) {

			if (range[j].end) {

				k = j;

				break;

			}

		}

		if (j == i)

			break;

		range[i].start = range[k].start;

		range[i].end   = range[k].end;

		range[k].start = 0;

		range[k].end   = 0;

		k--;

	}

	/* count it */

	for (i = 0; i < az; i++) {

		if (!range[i].end) {

			nr_range = i;

			break;

		}

	}



	/* sort them */

	sort(range, nr_range, sizeof(struct res_range), cmp_range, NULL);



	return nr_range;

}



#define BIOS_BUG_MSG KERN_WARNING \

	"WARNING: BIOS bug: VAR MTRR %d contains strange UC entry under 1M, check with your system vendor!\n"
@@ -223,22 +258,18 @@ x86_get_mtrr_mem_range(struct res_range *range, int nr_range, 
		subtract_range(range, extra_remove_base,

				 extra_remove_base + extra_remove_size  - 1);



	/* get new range num */

	nr_range = 0;

	if  (debug_print) {

		printk(KERN_DEBUG "After UC checking\n");

		for (i = 0; i < RANGE_NUM; i++) {

			if (!range[i].end)

				continue;

		nr_range++;

	}

	if  (debug_print) {

		printk(KERN_DEBUG "After UC checking\n");

		for (i = 0; i < nr_range; i++)

			printk(KERN_DEBUG "MTRR MAP PFN: %016lx - %016lx\n",

				 range[i].start, range[i].end + 1);

		}

	}



	/* sort the ranges */

	sort(range, nr_range, sizeof(struct res_range), cmp_range, NULL);

	nr_range = clean_sort_range(range, RANGE_NUM);

	if  (debug_print) {

		printk(KERN_DEBUG "After sorting\n");

		for (i = 0; i < nr_range; i++)