[POWERPC] Reworking machine check handling and Fix 440/440A

This adds a cputable function pointer for the CPU-side machine
check handling. The semantic is still the same as the old one,
the one in ppc_md. overrides the one in cputable, though
ultimately we'll want to change that so the CPU gets first.

This removes CONFIG_440A which was a problem for multiplatform
kernels and instead fixes up the IVOR at runtime from a setup_cpu
function. The "A" version of the machine check also tweaks the
regs->trap value to differenciate the 2 versions at the C level.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>

1 files changed, 67 insertions, 31 deletions

diff --git a/arch/ppc/kernel/traps.c b/arch/ppc/kernel/traps.c
index c78568905c3b..25a1085fbd01 100644
--- a/arch/ppc/kernel/traps.c
+++ b/arch/ppc/kernel/traps.c
@@ -231,39 +231,25 @@ platform_machine_check(struct pt_regs *regs)
 {
 }
 
-void machine_check_exception(struct pt_regs *regs)
+#if defined(CONFIG_4xx)
+int machine_check_4xx(struct pt_regs *regs)
 {
         unsigned long reason = get_mc_reason(regs);
 
-        if (user_mode(regs)) {
-                regs->msr |= MSR_RI;
-                _exception(SIGBUS, regs, BUS_ADRERR, regs->nip);
-                return;
-        }
-
-#if defined(CONFIG_8xx) && defined(CONFIG_PCI)
-        /* the qspan pci read routines can cause machine checks -- Cort */
-        bad_page_fault(regs, regs->dar, SIGBUS);
-        return;
-#endif
-
-        if (debugger_fault_handler) {
-                debugger_fault_handler(regs);
-                regs->msr |= MSR_RI;
-                return;
-        }
-
-        if (check_io_access(regs))
-                return;
-
-#if defined(CONFIG_4xx) && !defined(CONFIG_440A)
         if (reason & ESR_IMCP) {
                 printk("Instruction");
                 mtspr(SPRN_ESR, reason & ~ESR_IMCP);
         } else
                 printk("Data");
         printk(" machine check in kernel mode.\n");
-#elif defined(CONFIG_440A)
+
+        return 0;
+}
+
+int machine_check_440A(struct pt_regs *regs)
+{
+        unsigned long reason = get_mc_reason(regs);
+
         printk("Machine check in kernel mode.\n");
         if (reason & ESR_IMCP){
                 printk("Instruction Synchronous Machine Check exception\n");
@@ -293,7 +279,13 @@ void machine_check_exception(struct pt_regs *regs)
                 /* Clear MCSR */
                 mtspr(SPRN_MCSR, mcsr);
         }
-#elif defined (CONFIG_E500)
+        return 0;
+}
+#elif defined(CONFIG_E500)
+int machine_check_e500(struct pt_regs *regs)
+{
+        unsigned long reason = get_mc_reason(regs);
+
         printk("Machine check in kernel mode.\n");
         printk("Caused by (from MCSR=%lx): ", reason);
 
@@ -305,8 +297,6 @@ void machine_check_exception(struct pt_regs *regs)
                 printk("Data Cache Push Parity Error\n");
         if (reason & MCSR_DCPERR)
                 printk("Data Cache Parity Error\n");
-        if (reason & MCSR_GL_CI)
-                printk("Guarded Load or Cache-Inhibited stwcx.\n");
         if (reason & MCSR_BUS_IAERR)
                 printk("Bus - Instruction Address Error\n");
         if (reason & MCSR_BUS_RAERR)
@@ -318,12 +308,19 @@ void machine_check_exception(struct pt_regs *regs)
         if (reason & MCSR_BUS_RBERR)
                 printk("Bus - Read Data Bus Error\n");
         if (reason & MCSR_BUS_WBERR)
-                printk("Bus - Write Data Bus Error\n");
+                printk("Bus - Read Data Bus Error\n");
         if (reason & MCSR_BUS_IPERR)
                 printk("Bus - Instruction Parity Error\n");
         if (reason & MCSR_BUS_RPERR)
                 printk("Bus - Read Parity Error\n");
-#elif defined (CONFIG_E200)
+
+        return 0;
+}
+#elif defined(CONFIG_E200)
+int machine_check_e200(struct pt_regs *regs)
+{
+        unsigned long reason = get_mc_reason(regs);
+
         printk("Machine check in kernel mode.\n");
         printk("Caused by (from MCSR=%lx): ", reason);
 
@@ -341,7 +338,14 @@ void machine_check_exception(struct pt_regs *regs)
                 printk("Bus - Read Bus Error on data load\n");
         if (reason & MCSR_BUS_WRERR)
                 printk("Bus - Write Bus Error on buffered store or cache line push\n");
-#else /* !CONFIG_4xx && !CONFIG_E500 && !CONFIG_E200 */
+
+        return 0;
+}
+#else
+int machine_check_generic(struct pt_regs *regs)
+{
+        unsigned long reason = get_mc_reason(regs);
+
         printk("Machine check in kernel mode.\n");
         printk("Caused by (from SRR1=%lx): ", reason);
         switch (reason & 0x601F0000) {
@@ -371,7 +375,39 @@ void machine_check_exception(struct pt_regs *regs)
         default:
                 printk("Unknown values in msr\n");
         }
-#endif /* CONFIG_4xx */
+        return 0;
+}
+#endif /* everything else */
+
+void machine_check_exception(struct pt_regs *regs)
+{
+        int recover = 0;
+
+        if (cur_cpu_spec->machine_check)
+                recover = cur_cpu_spec->machine_check(regs);
+        if (recover > 0)
+                return;
+
+        if (user_mode(regs)) {
+                regs->msr |= MSR_RI;
+                _exception(SIGBUS, regs, BUS_ADRERR, regs->nip);
+                return;
+        }
+
+#if defined(CONFIG_8xx) && defined(CONFIG_PCI)
+        /* the qspan pci read routines can cause machine checks -- Cort */
+        bad_page_fault(regs, regs->dar, SIGBUS);
+        return;
+#endif
+
+        if (debugger_fault_handler) {
+                debugger_fault_handler(regs);
+                regs->msr |= MSR_RI;
+                return;
+        }
+
+        if (check_io_access(regs))
+                return;
 
         /*
          * Optional platform-provided routine to print out