Commit f86593be authored by Mahesh Salgaonkar's avatar Mahesh Salgaonkar Committed by Michael Ellerman
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powerpc/fadump: Throw proper error message on fadump registration failure 



fadump fails to register when there are holes in reserved memory area.
This can happen if user has hot-removed a memory that falls in the
fadump reserved memory area. Throw a meaningful error message to the
user in such case.

Signed-off-by: default avatarMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
[mpe: is_reserved_memory_area_contiguous() returns bool, unsplit string]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent a4e92ce8

arch/powerpc/kernel/fadump.c

+33 −2
Original line number Diff line number Diff line
@@ -237,6 +237,35 @@ static int is_boot_memory_area_contiguous(void) 
	return ret;

}



/*

 * Returns true, if there are no holes in reserved memory area,

 * false otherwise.

 */

static bool is_reserved_memory_area_contiguous(void)

{

	struct memblock_region *reg;

	unsigned long start, end;

	unsigned long d_start = fw_dump.reserve_dump_area_start;

	unsigned long d_end = d_start + fw_dump.reserve_dump_area_size;



	for_each_memblock(memory, reg) {

		start = max(d_start, (unsigned long)reg->base);

		end = min(d_end, (unsigned long)(reg->base + reg->size));

		if (d_start < end) {

			/* Memory hole from d_start to start */

			if (start > d_start)

				break;



			if (end == d_end)

				return true;



			d_start = end + 1;

		}

	}



	return false;

}



/* Print firmware assisted dump configurations for debugging purpose. */

static void fadump_show_config(void)

{
@@ -603,7 +632,9 @@ static int register_fw_dump(struct fadump_mem_struct *fdm) 
		break;

	case -3:

		if (!is_boot_memory_area_contiguous())

			pr_err("Can't have holes in boot memory area while "

			pr_err("Can't have holes in boot memory area while registering fadump\n");

		else if (!is_reserved_memory_area_contiguous())

			pr_err("Can't have holes in reserved memory area while"

			       " registering fadump\n");



		printk(KERN_ERR "Failed to register firmware-assisted kernel"

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