Commit 2313c279 authored by Yinghai Lu's avatar Yinghai Lu Committed by Ingo Molnar
Browse files

x86: mtrr_cleanup optimization, v2 



fix hpa's t61 with 4g ram:

   change layout from
	(n - 1)*chunksize + chunk_size - NC
   to
	n*chunksize - NC

Signed-off-by: default avatarYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 7fc2368d

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

+37 −42
Original line number Diff line number Diff line
@@ -970,6 +970,8 @@ range_to_mtrr_with_hole(struct var_mtrr_state *state, unsigned long basek, 
	/* try to append some small hole */

	range0_basek = state->range_startk;

	range0_sizek = ALIGN(state->range_sizek, chunk_sizek);



	/* no increase */

	if (range0_sizek == state->range_sizek) {

		if (debug_print)

			printk(KERN_DEBUG "rangeX: %016lx - %016lx\n",
@@ -980,8 +982,8 @@ range_to_mtrr_with_hole(struct var_mtrr_state *state, unsigned long basek, 
		return 0;

	}



	range0_sizek -= chunk_sizek;

	if (range0_sizek && sizek) {

	/* only cut back, when it is not the last */

	if (sizek) {

		while (range0_basek + range0_sizek > (basek + sizek)) {

			range0_sizek -= chunk_sizek;

			if (!range0_sizek)
@@ -1000,46 +1002,39 @@ range_to_mtrr_with_hole(struct var_mtrr_state *state, unsigned long basek, 
	}



	range_basek = range0_basek + range0_sizek;

	range_sizek = chunk_sizek;



	if (range_basek + range_sizek > basek &&

	    range_basek + range_sizek <= (basek + sizek)) {

		/* one hole */

		second_basek = basek;

		second_sizek = range_basek + range_sizek - basek;

	}

	/* one hole in the middle */

	if (range_basek > basek && range_basek <= (basek + sizek))

		second_sizek = range_basek - basek;



	/* if last piece, only could one hole near end */

	if ((second_basek || !basek) &&

	    range_sizek - (state->range_sizek - range0_sizek) - second_sizek <

	    (chunk_sizek >> 1)) {

		/*

		 * one hole in middle (second_sizek is 0) or at end

		 * (second_sizek is 0 )

		 */

		hole_sizek = range_sizek - (state->range_sizek - range0_sizek)

				 - second_sizek;

		hole_basek = range_basek + range_sizek - hole_sizek

				 - second_sizek;

	} else {

		/* fallback for big hole, or several holes */

		range_sizek = state->range_sizek - range0_sizek;

		second_basek = 0;

		second_sizek = 0;

	}

	if (range0_sizek > state->range_sizek) {

		unsigned long hole_basek, hole_sizek;



	if (debug_print)

		printk(KERN_DEBUG "range: %016lx - %016lx\n", range_basek<<10,

			 (range_basek + range_sizek)<<10);

	state->reg = range_to_mtrr(state->reg, range_basek, range_sizek,

					 MTRR_TYPE_WRBACK);

		/* one hole in middle or at end */

		hole_sizek = range0_sizek - state->range_sizek - second_sizek;

		if (hole_sizek) {

			hole_basek = range_basek - hole_sizek - second_sizek;

			if (debug_print)

				printk(KERN_DEBUG "hole: %016lx - %016lx\n",

				 hole_basek<<10, (hole_basek + hole_sizek)<<10);

		state->reg = range_to_mtrr(state->reg, hole_basek, hole_sizek,

					 hole_basek<<10,

					 (hole_basek + hole_sizek)<<10);

			state->reg = range_to_mtrr(state->reg, hole_basek,

						   hole_sizek,

						   MTRR_TYPE_UNCACHABLE);

		}

	} else  {

		/* need to handle left over */

		range_sizek = state->range_sizek - range0_sizek;



		if (range_sizek) {

			if (debug_print)

				printk(KERN_DEBUG "range: %016lx - %016lx\n",

					 range_basek<<10,

					 (range_basek + range_sizek)<<10);

			state->reg = range_to_mtrr(state->reg, range_basek,

					 range_sizek,

					 MTRR_TYPE_WRBACK);

		}

	}



	return second_sizek;