Merge tag 'spi-v3.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

[linux-imx.git] / arch / arm / include / asm / cputype.h

diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h
index 8c25dc4e98514d85db8ce77f4d9e7fa8f828262d..9672e978d50df67d94c3dd86d23f3bcdd187c54d 100644 (file)
--- a/arch/arm/include/asm/cputype.h
+++ b/arch/arm/include/asm/cputype.h
@@ -89,13 +89,18 @@ extern unsigned int processor_id;
                __val;                                                  \
        })
 
+/*
+ * The memory clobber prevents gcc 4.5 from reordering the mrc before
+ * any is_smp() tests, which can cause undefined instruction aborts on
+ * ARM1136 r0 due to the missing extended CP15 registers.
+ */
 #define read_cpuid_ext(ext_reg)                                                \
        ({                                                              \
                unsigned int __val;                                     \
                asm("mrc        p15, 0, %0, c0, " ext_reg               \
                    : "=r" (__val)                                      \
                    :                                                   \
-                   : "cc");                                            \
+                   : "memory");                                        \
                __val;                                                  \
        })