microblaze_mmu_v2: Add MMU related exceptions handling

Signed-off-by: Michal Simek <monstr@monstr.eu>

1 files changed, 37 insertions, 8 deletions

diff --git a/arch/microblaze/kernel/exceptions.c b/arch/microblaze/kernel/exceptions.c
index 4a8a4064c7ee..0cb64a31e89a 100644
--- a/arch/microblaze/kernel/exceptions.c
+++ b/arch/microblaze/kernel/exceptions.c
@@ -21,9 +21,9 @@
 
 #include <asm/exceptions.h>
 #include <asm/entry.h>          /* For KM CPU var */
-#include <asm/uaccess.h>
-#include <asm/errno.h>
-#include <asm/ptrace.h>
+#include <linux/uaccess.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
 #include <asm/current.h>
 
 #define MICROBLAZE_ILL_OPCODE_EXCEPTION 0x02
@@ -31,7 +31,7 @@
 #define MICROBLAZE_DBUS_EXCEPTION       0x04
 #define MICROBLAZE_DIV_ZERO_EXCEPTION   0x05
 #define MICROBLAZE_FPU_EXCEPTION        0x06
-#define MICROBLAZE_PRIVILEG_EXCEPTION   0x07
+#define MICROBLAZE_PRIVILEGED_EXCEPTION 0x07
 
 static DEFINE_SPINLOCK(die_lock);
 
@@ -66,6 +66,11 @@ void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
 asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
                                                         int fsr, int addr)
 {
+#ifdef CONFIG_MMU
+        int code;
+        addr = regs->pc;
+#endif
+
 #if 0
         printk(KERN_WARNING "Exception %02x in %s mode, FSR=%08x PC=%08x ESR=%08x\n",
                         type, user_mode(regs) ? "user" : "kernel", fsr,
@@ -74,7 +79,13 @@ asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
 
         switch (type & 0x1F) {
         case MICROBLAZE_ILL_OPCODE_EXCEPTION:
-                _exception(SIGILL, regs, ILL_ILLOPC, addr);
+                if (user_mode(regs)) {
+                        printk(KERN_WARNING "Illegal opcode exception in user mode.\n");
+                        _exception(SIGILL, regs, ILL_ILLOPC, addr);
+                        return;
+                }
+                printk(KERN_WARNING "Illegal opcode exception in kernel mode.\n");
+                die("opcode exception", regs, SIGBUS);
                 break;
         case MICROBLAZE_IBUS_EXCEPTION:
                 if (user_mode(regs)) {
@@ -95,11 +106,16 @@ asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
                 die("bus exception", regs, SIGBUS);
                 break;
         case MICROBLAZE_DIV_ZERO_EXCEPTION:
-                printk(KERN_WARNING "Divide by zero exception\n");
-                _exception(SIGILL, regs, ILL_ILLOPC, addr);
+                if (user_mode(regs)) {
+                        printk(KERN_WARNING "Divide by zero exception in user mode\n");
+                        _exception(SIGILL, regs, ILL_ILLOPC, addr);
+                        return;
+                }
+                printk(KERN_WARNING "Divide by zero exception in kernel mode.\n");
+                die("Divide by exception", regs, SIGBUS);
                 break;
-
         case MICROBLAZE_FPU_EXCEPTION:
+                printk(KERN_WARNING "FPU exception\n");
                 /* IEEE FP exception */
                 /* I removed fsr variable and use code var for storing fsr */
                 if (fsr & FSR_IO)
@@ -115,7 +131,20 @@ asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
                 _exception(SIGFPE, regs, fsr, addr);
                 break;
 
+#ifdef CONFIG_MMU
+        case MICROBLAZE_PRIVILEGED_EXCEPTION:
+                printk(KERN_WARNING "Privileged exception\n");
+                /* "brk r0,r0" - used as debug breakpoint */
+                if (get_user(code, (unsigned long *)regs->pc) == 0
+                        && code == 0x980c0000) {
+                        _exception(SIGTRAP, regs, TRAP_BRKPT, addr);
+                } else {
+                        _exception(SIGILL, regs, ILL_PRVOPC, addr);
+                }
+                break;
+#endif
         default:
+        /* FIXME what to do in unexpected exception */
                 printk(KERN_WARNING "Unexpected exception %02x "
                         "PC=%08x in %s mode\n", type, (unsigned int) addr,
                         kernel_mode(regs) ? "kernel" : "user");