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Commit 8f0afaa5 authored by Yinghai Lu's avatar Yinghai Lu Committed by Ingo Molnar
Browse files

x86: mtrr_cleanup hole size should be less than half of chunk_size, v2 



v2: should check with half of range0 size instead of chunk_size

So don't have silly big hole.

in hpa's case we could auto detect instead of adding mtrr_chunk_size in
command line.

Signed-off-by: default avatarYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 54d45ff4

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

+43 −31
Original line number Diff line number Diff line
@@ -992,22 +992,17 @@ range_to_mtrr_with_hole(struct var_mtrr_state *state, unsigned long basek, 
	/* only cut back, when it is not the last */

	if (sizek) {

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

			if (range0_sizek >= chunk_sizek)

				range0_sizek -= chunk_sizek;

			else

				range0_sizek = 0;



			if (!range0_sizek)

				break;

		}

	}



	if (range0_sizek) {

		if (debug_print)

			printk(KERN_DEBUG "range0: %016lx - %016lx\n",

				range0_basek<<10,

				(range0_basek + range0_sizek)<<10);

		state->reg = range_to_mtrr(state->reg, range0_basek,

				range0_sizek, MTRR_TYPE_WRBACK);



	}



second_try:

	range_basek = range0_basek + range0_sizek;



	/* one hole in the middle */
@@ -1015,33 +1010,50 @@ range_to_mtrr_with_hole(struct var_mtrr_state *state, unsigned long basek, 
		second_sizek = range_basek - basek;



	if (range0_sizek > state->range_sizek) {

		unsigned long hole_basek, hole_sizek;



		/* 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;



		/* hole size should be less than half of range0 size */

		if (hole_sizek > (range0_sizek >> 1) &&

		    range0_sizek >= chunk_sizek) {

			range0_sizek -= chunk_sizek;

			second_sizek = 0;

			hole_sizek = 0;



			goto second_try;

		}

	}



	if (range0_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,

						   MTRR_TYPE_UNCACHABLE);

			printk(KERN_DEBUG "range0: %016lx - %016lx\n",

				range0_basek<<10,

				(range0_basek + range0_sizek)<<10);

		state->reg = range_to_mtrr(state->reg, range0_basek,

				range0_sizek, MTRR_TYPE_WRBACK);

	}

	} else  {



	if (range0_sizek < state->range_sizek) {

		/* 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);

				 range_sizek, MTRR_TYPE_WRBACK);

	}



	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, MTRR_TYPE_UNCACHABLE);

	}



	return second_sizek;