Blackfin arch: ensure we work around ANOMALY_05000261 for null pointers

 We currently do not. Also make it easier to handle cplb violations - in traps.c

Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>

2 files changed, 33 insertions, 15 deletions

diff --git a/arch/blackfin/kernel/traps.c b/arch/blackfin/kernel/traps.c
index cfa05436c972..aaddb724a5fb 100644
--- a/arch/blackfin/kernel/traps.c
+++ b/arch/blackfin/kernel/traps.c
@@ -311,11 +311,10 @@ asmlinkage void trap_c(struct pt_regs *fp)
                 printk(KERN_NOTICE EXC_0x22);
                 CHK_DEBUGGER_TRAP();
                 break;
-        /* 0x23 - Data CPLB Protection Violation,
-                 normal case is handled in _cplb_hdr */
+        /* 0x23 - Data CPLB protection violation, handled here */
         case VEC_CPLB_VL:
                 info.si_code = ILL_CPLB_VI;
-                sig = SIGILL;
+                sig = SIGBUS;
                 printk(KERN_NOTICE EXC_0x23);
                 CHK_DEBUGGER_TRAP();
                 break;
@@ -382,11 +381,10 @@ asmlinkage void trap_c(struct pt_regs *fp)
                 printk(KERN_NOTICE EXC_0x2A);
                 CHK_DEBUGGER_TRAP();
                 break;
-        /* 0x2B - Instruction CPLB protection Violation,
-                handled in _cplb_hdr */
+        /* 0x2B - Instruction CPLB protection violation, handled here */
         case VEC_CPLB_I_VL:
                 info.si_code = ILL_CPLB_VI;
-                sig = SIGILL;
+                sig = SIGBUS;
                 printk(KERN_NOTICE EXC_0x2B);
                 CHK_DEBUGGER_TRAP();
                 break;
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index 1b13fa470977..54712f9a60ac 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -71,13 +71,18 @@ ENDPROC(_safe_speculative_execution)
  * This one does not lower the level to IRQ5, and thus can be used to
  * patch up CPLB misses on the kernel stack.
  */
-ENTRY(_ex_dcplb)
 #if ANOMALY_05000261
+#define _ex_dviol _ex_workaround_261
+#define _ex_dmiss _ex_workaround_261
+#define _ex_dmult _ex_workaround_261
+
+ENTRY(_ex_workaround_261)
         /*
          * Work around an anomaly: if we see a new DCPLB fault, return
          * without doing anything.  Then, if we get the same fault again,
          * handle it.
          */
+        P4 = R7;        /* Store EXCAUSE */
         p5.l = _last_cplb_fault_retx;
         p5.h = _last_cplb_fault_retx;
         r7 = [p5];
@@ -86,10 +91,24 @@ ENTRY(_ex_dcplb)
         cc = r6 == r7;
         if !cc jump _return_from_exception;
         /* fall through */
+        R7 = P4;
+        R6 = 0x26;      /* Data CPLB Miss */
+        cc = R6 == R7;
+        if cc jump _ex_dcplb_miss (BP);
+        /* Handle 0x23 Data CPLB Protection Violation
+         * and Data CPLB Multiple Hits - Linux Trap Zero
+         */
+        jump _ex_trap_c;
+ENDPROC(_ex_workaround_261)
+
+#else
+#define _ex_dviol _ex_trap_c
+#define _ex_dmiss _ex_dcplb_miss
+#define _ex_dmult _ex_trap_c
 #endif
-ENDPROC(_ex_dcplb)
 
-ENTRY(_ex_icplb)
+ENTRY(_ex_dcplb_miss)
+ENTRY(_ex_icplb_miss)
         (R7:6,P5:4) = [sp++];
         ASTAT = [sp++];
         SAVE_ALL_SYS
@@ -98,7 +117,7 @@ ENTRY(_ex_icplb)
         RESTORE_ALL_SYS
         SP = EX_SCRATCH_REG;
         rtx;
-ENDPROC(_ex_icplb)
+ENDPROC(_ex_icplb_miss)
 
 ENTRY(_ex_syscall)
         DEBUG_START_HWTRACE(p5, r7)
@@ -908,6 +927,7 @@ ENDPROC(_early_trap)
 #else
 .data
 #endif
+
 ENTRY(_ex_table)
         /* entry for each EXCAUSE[5:0]
          * This table must be in sync with the table in ./kernel/traps.c
@@ -952,16 +972,16 @@ ENTRY(_ex_table)
         .long _ex_trap_c        /* 0x20 - Reserved */
         .long _ex_trap_c        /* 0x21 - Undefined Instruction */
         .long _ex_trap_c        /* 0x22 - Illegal Instruction Combination */
-        .long _ex_dcplb         /* 0x23 - Data CPLB Protection Violation */
+        .long _ex_dviol         /* 0x23 - Data CPLB Protection Violation */
         .long _ex_trap_c        /* 0x24 - Data access misaligned */
         .long _ex_trap_c        /* 0x25 - Unrecoverable Event */
-        .long _ex_dcplb         /* 0x26 - Data CPLB Miss */
-        .long _ex_trap_c        /* 0x27 - Data CPLB Multiple Hits - Linux Trap Zero */
+        .long _ex_dmiss         /* 0x26 - Data CPLB Miss */
+        .long _ex_dmult         /* 0x27 - Data CPLB Multiple Hits - Linux Trap Zero */
         .long _ex_trap_c        /* 0x28 - Emulation Watchpoint */
         .long _ex_trap_c        /* 0x29 - Instruction fetch access error (535 only) */
         .long _ex_trap_c        /* 0x2A - Instruction fetch misaligned */
-        .long _ex_icplb         /* 0x2B - Instruction CPLB protection Violation */
-        .long _ex_icplb         /* 0x2C - Instruction CPLB miss */
+        .long _ex_trap_c        /* 0x2B - Instruction CPLB protection Violation */
+        .long _ex_icplb_miss    /* 0x2C - Instruction CPLB miss */
         .long _ex_trap_c        /* 0x2D - Instruction CPLB Multiple Hits */
         .long _ex_trap_c        /* 0x2E - Illegal use of Supervisor Resource */
         .long _ex_trap_c        /* 0x2E - Illegal use of Supervisor Resource */