MN10300: Add built-in testing for misalignment handler

Add configurable built-in testing for the MN10300 misalignment handler.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 170 insertions, 0 deletions

diff --git a/arch/mn10300/Kconfig.debug b/arch/mn10300/Kconfig.debug
index 524e33819f32..ff80e86b9bd2 100644
--- a/arch/mn10300/Kconfig.debug
+++ b/arch/mn10300/Kconfig.debug
@@ -15,6 +15,15 @@ config DEBUG_DECOMPRESS_KERNEL
           decompressing Linux seeing "Uncompressing Linux... " and
           "Ok, booting the kernel.\n" on console.
 
+config TEST_MISALIGNMENT_HANDLER
+        bool "Run tests on the misalignment handler"
+        depends on DEBUG_KERNEL
+        default n
+        help
+          If you say Y here the kernel will execute a list of misaligned memory
+          accesses to make sure the misalignment handler deals them with
+          correctly.  If it does not, the kernel will throw a BUG.
+
 config KPROBES
         bool "Kprobes"
         depends on DEBUG_KERNEL
diff --git a/arch/mn10300/mm/misalignment.c b/arch/mn10300/mm/misalignment.c
index 416c43baaa21..93e09c4be1db 100644
--- a/arch/mn10300/mm/misalignment.c
+++ b/arch/mn10300/mm/misalignment.c
@@ -650,3 +650,164 @@ static int misalignment_reg(unsigned long *registers, unsigned params,
 
         return 1;
 }
+
+/*
+ * misalignment handler tests
+ */
+#ifdef CONFIG_TEST_MISALIGNMENT_HANDLER
+static u8 __initdata testbuf[512] __attribute__((aligned(16))) = {
+        [257] = 0x11,
+        [258] = 0x22,
+        [259] = 0x33,
+        [260] = 0x44,
+};
+
+#define ASSERTCMP(X, OP, Y)                                             \
+do {                                                                    \
+        if (unlikely(!((X) OP (Y)))) {                                  \
+                printk(KERN_ERR "\n");                                  \
+                printk(KERN_ERR "MISALIGN: Assertion failed at line %u\n", \
+                       __LINE__);                                       \
+                printk(KERN_ERR "0x%lx " #OP " 0x%lx is false\n",       \
+                       (unsigned long)(X), (unsigned long)(Y));         \
+                BUG();                                                  \
+        }                                                               \
+} while(0)
+
+static int __init test_misalignment(void)
+{
+        register void *r asm("e0");
+        register u32 y asm("e1");
+        void *p = testbuf, *q;
+        u32 tmp, tmp2, x;
+
+        printk(KERN_NOTICE "==>test_misalignment() [testbuf=%p]\n", p);
+        p++;
+
+        printk(KERN_NOTICE "___ MOV (Am),Dn ___\n");
+        q = p + 256;
+        asm volatile("mov       (%0),%1" : "+a"(q), "=d"(x));
+        ASSERTCMP(q, ==, p + 256);
+        ASSERTCMP(x, ==, 0x44332211);
+
+        printk(KERN_NOTICE "___ MOV (256,Am),Dn ___\n");
+        q = p;
+        asm volatile("mov       (256,%0),%1" : "+a"(q), "=d"(x));
+        ASSERTCMP(q, ==, p);
+        ASSERTCMP(x, ==, 0x44332211);
+
+        printk(KERN_NOTICE "___ MOV (Di,Am),Dn ___\n");
+        tmp = 256;
+        q = p;
+        asm volatile("mov       (%2,%0),%1" : "+a"(q), "=d"(x), "+d"(tmp));
+        ASSERTCMP(q, ==, p);
+        ASSERTCMP(x, ==, 0x44332211);
+        ASSERTCMP(tmp, ==, 256);
+
+        printk(KERN_NOTICE "___ MOV (256,Rm),Rn ___\n");
+        r = p;
+        asm volatile("mov       (256,%0),%1" : "+r"(r), "=r"(y));
+        ASSERTCMP(r, ==, p);
+        ASSERTCMP(y, ==, 0x44332211);
+
+        printk(KERN_NOTICE "___ MOV (Rm+),Rn ___\n");
+        r = p + 256;
+        asm volatile("mov       (%0+),%1" : "+r"(r), "=r"(y));
+        ASSERTCMP(r, ==, p + 256 + 4);
+        ASSERTCMP(y, ==, 0x44332211);
+
+        printk(KERN_NOTICE "___ MOV (Rm+,8),Rn ___\n");
+        r = p + 256;
+        asm volatile("mov       (%0+,8),%1" : "+r"(r), "=r"(y));
+        ASSERTCMP(r, ==, p + 256 + 8);
+        ASSERTCMP(y, ==, 0x44332211);
+
+        printk(KERN_NOTICE "___ MOV (7,SP),Rn ___\n");
+        asm volatile(
+                "add    -16,sp          \n"
+                "mov    +0x11,%0        \n"
+                "movbu  %0,(7,sp)       \n"
+                "mov    +0x22,%0        \n"
+                "movbu  %0,(8,sp)       \n"
+                "mov    +0x33,%0        \n"
+                "movbu  %0,(9,sp)       \n"
+                "mov    +0x44,%0        \n"
+                "movbu  %0,(10,sp)      \n"
+                "mov    (7,sp),%1       \n"
+                "add    +16,sp          \n"
+                : "+a"(q), "=d"(x));
+        ASSERTCMP(x, ==, 0x44332211);
+
+        printk(KERN_NOTICE "___ MOV (259,SP),Rn ___\n");
+        asm volatile(
+                "add    -264,sp         \n"
+                "mov    +0x11,%0        \n"
+                "movbu  %0,(259,sp)     \n"
+                "mov    +0x22,%0        \n"
+                "movbu  %0,(260,sp)     \n"
+                "mov    +0x33,%0        \n"
+                "movbu  %0,(261,sp)     \n"
+                "mov    +0x55,%0        \n"
+                "movbu  %0,(262,sp)     \n"
+                "mov    (259,sp),%1     \n"
+                "add    +264,sp         \n"
+                : "+d"(tmp), "=d"(x));
+        ASSERTCMP(x, ==, 0x55332211);
+
+        printk(KERN_NOTICE "___ MOV (260,SP),Rn ___\n");
+        asm volatile(
+                "add    -264,sp         \n"
+                "mov    +0x11,%0        \n"
+                "movbu  %0,(260,sp)     \n"
+                "mov    +0x22,%0        \n"
+                "movbu  %0,(261,sp)     \n"
+                "mov    +0x33,%0        \n"
+                "movbu  %0,(262,sp)     \n"
+                "mov    +0x55,%0        \n"
+                "movbu  %0,(263,sp)     \n"
+                "mov    (260,sp),%1     \n"
+                "add    +264,sp         \n"
+                : "+d"(tmp), "=d"(x));
+        ASSERTCMP(x, ==, 0x55332211);
+
+
+        printk(KERN_NOTICE "___ MOV_LNE ___\n");
+        tmp = 1;
+        tmp2 = 2;
+        q = p + 256;
+        asm volatile(
+                "setlb                  \n"
+                "mov    %2,%3           \n"
+                "mov    %1,%2           \n"
+                "cmp    +0,%1           \n"
+                "mov_lne        (%0+,4),%1"
+                : "+r"(q), "+d"(tmp), "+d"(tmp2), "=d"(x)
+                :
+                : "cc");
+        ASSERTCMP(q, ==, p + 256 + 12);
+        ASSERTCMP(x, ==, 0x44332211);
+
+        printk(KERN_NOTICE "___ MOV in SETLB ___\n");
+        tmp = 1;
+        tmp2 = 2;
+        q = p + 256;
+        asm volatile(
+                "setlb                  \n"
+                "mov    %1,%3           \n"
+                "mov    (%0+),%1        \n"
+                "cmp    +0,%1           \n"
+                "lne                    "
+                : "+a"(q), "+d"(tmp), "+d"(tmp2), "=d"(x)
+                :
+                : "cc");
+
+        ASSERTCMP(q, ==, p + 256 + 8);
+        ASSERTCMP(x, ==, 0x44332211);
+
+        printk(KERN_NOTICE "<==test_misalignment()\n");
+        return 0;
+}
+
+arch_initcall(test_misalignment);
+
+#endif /* CONFIG_TEST_MISALIGNMENT_HANDLER */