From: Miodrag Dinic <miodrag.dinic@xxxxxxxxxx>
Implement support for parsing 'memmap' kernel command line parameter.
This patch covers parsing of the following two formats for 'memmap'
parameter values:
- nn[KMG]@ss[KMG]
- nn[KMG]$ss[KMG]
([KMG] = K M or G (kilo, mega, giga))
These two allowed formats for parameter value are already documented
in file kernel-parameters.txt in Documentation/admin-guide folder.
Some architectures already support them, but Mips did not prior to
this patch.
Excerpt from Documentation/admin-guide/kernel-parameters.txt:
memmap=nn[KMG]@ss[KMG]
[KNL] Force usage of a specific region of memory.
Region of memory to be used is from ss to ss+nn.
memmap=nn[KMG]$ss[KMG]
Mark specific memory as reserved.
Region of memory to be reserved is from ss to ss+nn.
Example: Exclude memory from 0x18690000-0x1869ffff
memmap=64K$0x18690000
or
memmap=0x10000$0x18690000
There is no need to update this documentation file with respect to
this patch.
Signed-off-by: Miodrag Dinic <miodrag.dinic@xxxxxxxxxx>
Signed-off-by: Goran Ferenc <goran.ferenc@xxxxxxxxxx>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@xxxxxxxxxx>
---
arch/mips/kernel/setup.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index ccea90f..5a86da93 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -713,6 +713,46 @@ static int __init early_parse_mem(char *p)
}
early_param("mem", early_parse_mem);
+static int __init early_parse_memmap(char *p)
+{
+ char *oldp;
+ u64 start_at, mem_size;
+
+ if (!p)
+ return -EINVAL;
+
+ if (!strncmp(p, "exactmap", 8)) {
+ pr_err("\"memmap=exactmap\" invalid on MIPS\n");
+ return 0;
+ }
+
+ oldp = p;
+ mem_size = memparse(p, &p);
+ if (p == oldp)
+ return -EINVAL;
+
+ if (*p == '@') {
+ start_at = memparse(p+1, &p);
+ add_memory_region(start_at, mem_size, BOOT_MEM_RAM);
+ } else if (*p == '#') {
+ pr_err("\"memmap=nn#ss\" (force ACPI data) invalid on MIPS\n");
+ return -EINVAL;
+ } else if (*p == '$') {
+ start_at = memparse(p+1, &p);
+ add_memory_region(start_at, mem_size, BOOT_MEM_RESERVED);
+ } else {
+ pr_err("\"memmap\" invalid format!\n");
+ return -EINVAL;
+ }
+
+ if (*p == '\0') {
+ usermem = 1;
+ return 0;
+ } else
+ return -EINVAL;
+}
+early_param("memmap", early_parse_memmap);
+
#ifdef CONFIG_PROC_VMCORE
unsigned long setup_elfcorehdr, setup_elfcorehdr_size;
static int __init early_parse_elfcorehdr(char *p)
--
2.7.4
