ARM: make cr_alignment read-only #ifndef CONFIG_CPU_CP15
This makes cr_alignment a constant 0 to break code that tries to modify
the value as it's likely that it's built on wrong assumption when
CONFIG_CPU_CP15 isn't defined. For code that is only reading the value 0
is more or less a fine value to report.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Message-Id: 1358413196-5609-2-git-send-email-u.kleine-koenig@pengutronix.de (v8)
diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c
index b820eda..feeb3ea 100644
--- a/arch/arm/mm/alignment.c
+++ b/arch/arm/mm/alignment.c
@@ -964,12 +964,14 @@
return -ENOMEM;
#endif
+#ifdef CONFIG_CPU_CP15
if (cpu_is_v6_unaligned()) {
cr_alignment &= ~CR_A;
cr_no_alignment &= ~CR_A;
set_cr(cr_alignment);
ai_usermode = safe_usermode(ai_usermode, false);
}
+#endif
hook_fault_code(FAULT_CODE_ALIGNMENT, do_alignment, SIGBUS, BUS_ADRALN,
"alignment exception");
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index ce328c7..7c347bc 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -97,6 +97,7 @@
}
};
+#ifdef CONFIG_CPU_CP15
/*
* These are useful for identifying cache coherency
* problems by allowing the cache or the cache and
@@ -195,6 +196,22 @@
}
#endif
+#else /* ifdef CONFIG_CPU_CP15 */
+
+static int __init early_cachepolicy(char *p)
+{
+ pr_warning("cachepolicy kernel parameter not supported without cp15\n");
+}
+early_param("cachepolicy", early_cachepolicy);
+
+static int __init noalign_setup(char *__unused)
+{
+ pr_warning("noalign kernel parameter not supported without cp15\n");
+}
+__setup("noalign", noalign_setup);
+
+#endif /* ifdef CONFIG_CPU_CP15 / else */
+
#define PROT_PTE_DEVICE L_PTE_PRESENT|L_PTE_YOUNG|L_PTE_DIRTY|L_PTE_XN
#define PROT_SECT_DEVICE PMD_TYPE_SECT|PMD_SECT_AP_WRITE