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: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
[mpe: is_reserved_memory_area_contiguous() returns bool, unsplit string]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index ec937c7..b7f83d6 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -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)
{
@@ -603,8 +632,10 @@ 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 "
- "registering fadump\n");
+ 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"
" dump. Parameter Error(%d).\n", rc);