Currently, memory for fadump can be specified with fadump_reserve_mem=size,
where only a fixed size can be specified. This patch tries to extend this
syntax to support conditional reservation based on memory size, with the
below syntax:
fadump_reserve_mem=<range1>:<size1>[,<range2>:<size2>,...]
This syntax helps using the same commandline parameter for different system
memory sizes.
Signed-off-by: Hari Bathini <hbath...@linux.vnet.ibm.com>
---
arch/powerpc/kernel/fadump.c | 127 +++++++++++++++++++++++++++++++++++++++---
1 file changed, 118 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index d0af58b..a7fef3e 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -193,6 +193,121 @@ static unsigned long init_fadump_mem_struct(struct
fadump_mem_struct *fdm,
return addr;
}
+#define FADUMP_MEM_CMDLINE_PREFIX "fadump_reserve_mem="
+
+static __init char *get_last_fadump_reserve_mem(void)
+{
+ char *p = boot_command_line, *fadump_cmdline = NULL;
+
+ /* find fadump_reserve_mem and use the last one if there are more */
+ p = strstr(p, FADUMP_MEM_CMDLINE_PREFIX);
+ while (p) {
+ fadump_cmdline = p;
+ p = strstr(p+1, FADUMP_MEM_CMDLINE_PREFIX);
+ }
+
+ return fadump_cmdline;
+}
+
+#define parse_fadump_print(fmt, arg...) \
+ printk(KERN_INFO "fadump_reserve_mem: " fmt, ##arg)
+
+/*
+ * This function parses command line for fadump_reserve_mem=
+ *
+ * Supports the below two syntaxes:
+ * 1. fadump_reserve_mem=size
+ * 2. fadump_reserve_mem=ramsize-range:size[,...]
+ *
+ * Sets fw_dump.reserve_bootvar with the memory size
+ * provided, 0 otherwise
+ *
+ * The function returns -EINVAL on failure, 0 otherwise.
+ */
+static int __init parse_fadump_reserve_mem(void)
+{
+ char *cur, *tmp;
+ char *first_colon, *first_space;
+ char *fadump_cmdline;
+ unsigned long long system_ram;
+
+ fw_dump.reserve_bootvar = 0;
+ fadump_cmdline = get_last_fadump_reserve_mem();
+
+ /* when no fadump_reserve_mem= cmdline option is provided */
+ if (!fadump_cmdline)
+ return 0;
+
+ first_colon = strchr(fadump_cmdline, ':');
+ first_space = strchr(fadump_cmdline, ' ');
+ cur = fadump_cmdline + strlen(FADUMP_MEM_CMDLINE_PREFIX);
+
+ /* for fadump_reserve_mem=size cmdline syntax */
+ if (!first_colon || (first_space && (first_colon > first_space))) {
+ fw_dump.reserve_bootvar = memparse(cur, &cur);
+ return 0;
+ }
+
+ /* for fadump_reserve_mem=ramsize-range:size[,...] cmdline syntax */
+ system_ram = memblock_phys_mem_size();
+ /* for each entry of the comma-separated list */
+ do {
+ unsigned long long start, end = ULLONG_MAX, size;
+
+ /* get the start of the range */
+ start = memparse(cur, &tmp);
+ if (cur == tmp) {
+ parse_fadump_print("Memory value expected\n");
+ return -EINVAL;
+ }
+ cur = tmp;
+ if (*cur != '-') {
+ parse_fadump_print("'-' expected\n");
+ return -EINVAL;
+ }
+ cur++;
+
+ /* if no ':' is here, than we read the end */
+ if (*cur != ':') {
+ end = memparse(cur, &tmp);
+ if (cur == tmp) {
+ parse_fadump_print("Memory value expected\n");
+ return -EINVAL;
+ }
+ cur = tmp;
+ if (end <= start) {
+ parse_fadump_print("end <= start\n");
+ return -EINVAL;
+ }
+ }
+
+ if (*cur != ':') {
+ parse_fadump_print("':' expected\n");
+ return -EINVAL;
+ }
+ cur++;
+
+ size = memparse(cur, &tmp);
+ if (cur == tmp) {
+ parse_fadump_print("Memory value expected\n");
+ return -EINVAL;
+ }
+ cur = tmp;
+ if (size >= system_ram) {
+ parse_fadump_print("invalid size\n");
+ return -EINVAL;
+ }
+
+ /* match ? */
+ if (system_ram >= start && system_ram < end) {
+ fw_dump.reserve_bootvar = size;
+ break;
+ }
+ } while (*cur++ == ',');
+
+ return 0;
+}
+
/**
* fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
*
@@ -212,6 +327,9 @@ static inline unsigned long
fadump_calculate_reserve_size(void)
{
unsigned long size;
+ /* sets fw_dump.reserve_bootvar */
+ parse_fadump_reserve_mem();
+
/*
* Check if the size is specified through fadump_reserve_mem= cmdline
* option. If yes, then use that.
@@ -352,15 +470,6 @@ static int __init early_fadump_param(char *p)
}
early_param("fadump", early_fadump_param);
-/* Look for fadump_reserve_mem= cmdline option */
-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;
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