[PATCH v2 2/2] fadump: reserve param area if below boot_mem_top

[Sourabh Jain]

The param area is a memory region where the kernel places additional
command-line arguments for fadump kernel. Currently, the param memory
area is reserved in fadump kernel if it is above boot_mem_top. However,
it should be reserved if it is below boot_mem_top because the fadump
kernel already reserves memory from boot_mem_top to the end of DRAM.

Currently, there is no impact from not reserving param memory if it is
below boot_mem_top, as it is not used after the early boot phase of the
fadump kernel. However, if this changes in the future, it could lead to
issues in the fadump kernel.

Fixes: 3416c9daa6b1 ("powerpc/fadump: pass additional parameters when fadump is active")
Cc: Mahesh Salgaonkar <mahesh at linux.ibm.com>
Cc: Michael Ellerman <mpe at ellerman.id.au>
Acked-by: Hari Bathini <hbathini at linux.ibm.com>
Signed-off-by: Sourabh Jain <sourabhjain at linux.ibm.com>
---

Changelog:

Since v1: https://lore.kernel.org/all/20241104083528.99520-1-sourabhjain@linux.ibm.com/
  - Include Fixes and Acked-by tag in the commit message
  - No functional changes

---
 arch/powerpc/kernel/fadump.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 3a2863307863..3f3674060164 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -143,7 +143,7 @@ void __init fadump_append_bootargs(void)
 	if (!fw_dump.dump_active || !fw_dump.param_area_supported || !fw_dump.param_area)
 		return;
 
-	if (fw_dump.param_area >= fw_dump.boot_mem_top) {
+	if (fw_dump.param_area < fw_dump.boot_mem_top) {
 		if (memblock_reserve(fw_dump.param_area, COMMAND_LINE_SIZE)) {
 			pr_warn("WARNING: Can't use additional parameters area!\n");
 			fw_dump.param_area = 0;
-- 
2.46.2