[PATCH 1/2] powerpc/fadump: add a warning when 'fadump_reserve_mem=' is used

[Hari Bathini]

With commit 11550dc0a00b ("powerpc/fadump: reuse crashkernel parameter
for fadump memory reservation"), 'fadump_reserve_mem=' parameter is
deprecated in favor of 'crashkernel=' parameter. Add a warning if
'fadump_reserve_mem=' is still used.

Suggested-by: Prarit Bhargava <pra...@redhat.com>
Signed-off-by: Hari Bathini <hbath...@linux.vnet.ibm.com>
---
 arch/powerpc/kernel/fadump.c |   27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 466569e..c0db844 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -212,6 +212,10 @@ static inline unsigned long 
fadump_calculate_reserve_size(void)
        int ret;
        unsigned long long base, size;
 
+       if (fw_dump.reserve_bootvar)
+               pr_warn("'fadump_reserve_mem=' parameter is deprecated in "
+                       "favor of 'crashkernel=' parameter.\n");
+
        /*
         * Check if the size is specified through crashkernel= cmdline
         * option. If yes, then use that but ignore base as fadump
@@ -220,8 +224,18 @@ static inline unsigned long 
fadump_calculate_reserve_size(void)
        ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
                                &size, &base);
        if (ret == 0 && size > 0) {
+               if (fw_dump.reserve_bootvar)
+                       pr_info("Using 'crashkernel=' parameter for"
+                               " memory reservation.\n");
+
                fw_dump.reserve_bootvar = (unsigned long)size;
                return fw_dump.reserve_bootvar;
+       } else if (fw_dump.reserve_bootvar) {
+               /*
+                * 'fadump_reserve_mem=' is being used to reserve memory
+                * for firmware-assisted dump.
+                */
+               return fw_dump.reserve_bootvar;
        }
 
        /* divide by 20 to get 5% of value */
@@ -377,6 +391,19 @@ static int __init early_fadump_param(char *p)
 }
 early_param("fadump", early_fadump_param);
 
+/*
+ * Look for fadump_reserve_mem= cmdline option
+ * TODO: Remove references to 'fadump_reserve_mem=' parameter,
+ *       the sooner 'crashkernel=' parameter is accustomed to.
+ */
+static int __init early_fadump_reserve_mem(char *p)
+{
+       if (p)
+               fw_dump.reserve_bootvar = memparse(p, &p);
+       return 0;
+}
+early_param("fadump_reserve_mem", early_fadump_reserve_mem);
+
 static void register_fw_dump(struct fadump_mem_struct *fdm)
 {
        int rc;