Commit 28b1c57d authored by Yinghai Lu's avatar Yinghai Lu Committed by H. Peter Anvin
Browse files

x86: Dynamically increase early_res array size 



Use early_res_count to track the num, and use find_e820 to get a new
buffer, then copy from the old to the new one.

Also, clear early_res to prevent later invalid usage.

-v2 _check_and_double_early_res should take new start

Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
LKML-Reference: <1265793639-15071-14-git-send-email-yinghai@kernel.org>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 264ebb18

arch/x86/kernel/e820.c

+53 −0
Original line number Diff line number Diff line
@@ -916,6 +916,48 @@ void __init reserve_early_overlap_ok(u64 start, u64 end, char *name) 
	__reserve_early(start, end, name, 1);

}



static void __init __check_and_double_early_res(u64 start)

{

	u64 end, size, mem;

	struct early_res *new;



	/* do we have enough slots left ? */

	if ((max_early_res - early_res_count) > max(max_early_res/8, 2))

		return;



	/* double it */

	end = max_pfn_mapped << PAGE_SHIFT;

	size = sizeof(struct early_res) * max_early_res * 2;

	mem = find_e820_area(start, end, size, sizeof(struct early_res));



	if (mem == -1ULL)

		panic("can not find more space for early_res array");



	new = __va(mem);

	/* save the first one for own */

	new[0].start = mem;

	new[0].end = mem + size;

	new[0].overlap_ok = 0;

	/* copy old to new */

	if (early_res == early_res_x) {

		memcpy(&new[1], &early_res[0],

			 sizeof(struct early_res) * max_early_res);

		memset(&new[max_early_res+1], 0,

			 sizeof(struct early_res) * (max_early_res - 1));

		early_res_count++;

	} else {

		memcpy(&new[1], &early_res[1],

			 sizeof(struct early_res) * (max_early_res - 1));

		memset(&new[max_early_res], 0,

			 sizeof(struct early_res) * max_early_res);

	}

	memset(&early_res[0], 0, sizeof(struct early_res) * max_early_res);

	early_res = new;

	max_early_res *= 2;

	printk(KERN_DEBUG "early_res array is doubled to %d at [%llx - %llx]\n",

		max_early_res, mem, mem + size - 1);

}



/*

 * Most early reservations come here.

 *
@@ -929,6 +971,8 @@ void __init reserve_early(u64 start, u64 end, char *name) 
	if (start >= end)

		return;



	__check_and_double_early_res(end);



	drop_overlaps_that_are_ok(start, end);

	__reserve_early(start, end, name, 0);

}
@@ -957,6 +1001,10 @@ void __init early_res_to_bootmem(u64 start, u64 end) 
	for (i = 0; i < max_early_res && early_res[i].end; i++)

		count++;



	/* need to skip first one ?*/

	if (early_res != early_res_x)

		idx = 1;



	printk(KERN_INFO "(%d/%d early reservations) ==> bootmem [%010llx - %010llx]\n",

			 count - idx, max_early_res, start, end);

	for (i = idx; i < count; i++) {
@@ -974,6 +1022,11 @@ void __init early_res_to_bootmem(u64 start, u64 end) 
		reserve_bootmem_generic(final_start, final_end - final_start,

				BOOTMEM_DEFAULT);

	}

	/* clear them */

	memset(&early_res[0], 0, sizeof(struct early_res) * max_early_res);

	early_res = NULL;

	max_early_res = 0;

	early_res_count = 0;

}



/* Check for already reserved areas */

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