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authorMax Filippov <jcmvbkbc@gmail.com>2014-03-21 21:04:40 +0400
committerMax Filippov <jcmvbkbc@gmail.com>2014-04-02 01:35:54 +0400
commit06bd2824f7dcbfb8dcd13519239a53d13298d238 (patch)
tree249b0b2ae6c1b088c358b8b150dabe2b839c16db /arch/xtensa/mm
parent6232791833785ae591b211609f6f7c4faa7c6e55 (diff)
downloadop-kernel-dev-06bd2824f7dcbfb8dcd13519239a53d13298d238.zip
op-kernel-dev-06bd2824f7dcbfb8dcd13519239a53d13298d238.tar.gz
xtensa: handle memmap kernel option
This option is useful for reserving memory regions for secondary cores in AMP configurations. Implement the following memmap variants: - memmap=nn[KMG]@ss[KMG]: force usage of a specific region of memory; - memmap=nn[KMG]$ss[KMG]: mark specified memory as reserved; - memmap=nn[KMG]: set end of memory. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch/xtensa/mm')
-rw-r--r--arch/xtensa/mm/init.c50
1 files changed, 50 insertions, 0 deletions
diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c
index 5d23697..d70ba93 100644
--- a/arch/xtensa/mm/init.c
+++ b/arch/xtensa/mm/init.c
@@ -332,3 +332,53 @@ void free_initmem(void)
{
free_initmem_default(-1);
}
+
+static void __init parse_memmap_one(char *p)
+{
+ char *oldp;
+ unsigned long start_at, mem_size;
+
+ if (!p)
+ return;
+
+ oldp = p;
+ mem_size = memparse(p, &p);
+ if (p == oldp)
+ return;
+
+ switch (*p) {
+ case '@':
+ start_at = memparse(p + 1, &p);
+ add_sysmem_bank(start_at, start_at + mem_size);
+ break;
+
+ case '$':
+ start_at = memparse(p + 1, &p);
+ mem_reserve(start_at, start_at + mem_size, 0);
+ break;
+
+ case 0:
+ mem_reserve(mem_size, 0, 0);
+ break;
+
+ default:
+ pr_warn("Unrecognized memmap syntax: %s\n", p);
+ break;
+ }
+}
+
+static int __init parse_memmap_opt(char *str)
+{
+ while (str) {
+ char *k = strchr(str, ',');
+
+ if (k)
+ *k++ = 0;
+
+ parse_memmap_one(str);
+ str = k;
+ }
+
+ return 0;
+}
+early_param("memmap", parse_memmap_opt);
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