Parameters 'mem=', 'iommu=' and the like, which affect the iommu are
parsed early in the boot process. This parser looks for a parameter
substring like 'iommu=' in the cmdline string but it could also succeed
when cmdline string contains parameters like 'x_iommu=' or such leading
to undesired results. Add support to skip proceeding in such cases.
Fixes: 9b6b563c0d2d ("powerpc: Merge in the ppc64 version of the prom code.")
Cc: sta...@vger.kernel.org # 2.6.15+
Cc: Paul Mackerras <pau...@samba.org>
Signed-off-by: Hari Bathini <hbath...@linux.vnet.ibm.com>
---
arch/powerpc/kernel/prom_init.c | 22 +++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 723df83..7030145 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -594,6 +594,26 @@ static unsigned long prom_memparse(const char *ptr, const
char **retptr)
}
/*
+ * Check if str is a suffix of another param as "mem=" could
+ * be "iomem=" as well.
+ */
+static bool is_substring_param(const char *cmdline, const char *str)
+{
+ char *p;
+ bool ret = false;
+
+ if (cmdline == str)
+ ret = true;
+ else {
+ p = (char *)(str - 1);
+ if (*p == ' ' || *p == '"')
+ ret = true;
+ }
+
+ return ret;
+}
+
+/*
* Early parsing of the command line passed to the kernel, used for
* "mem=x" and the options that affect the iommu
*/
@@ -617,7 +637,7 @@ static void __init early_cmdline_parse(void)
#ifdef CONFIG_PPC64
opt = strstr(prom_cmd_line, "iommu=");
- if (opt) {
+ if (opt && is_substring_param(prom_cmd_line, opt)) {
prom_printf("iommu opt is: %s\n", opt);
opt += 6;
while (*opt && *opt == ' ')
