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

[mirror_ubuntu-bionic-kernel.git] / arch / powerpc / kernel / traps.c

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index cad64840fce49409c80d0dd0a9f970dd056ca15a..848a20475db8c29deafdfe12380b746d0d4613ad 100644 (file)
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -334,18 +334,25 @@ static inline int check_io_access(struct pt_regs *regs)
 #define clear_single_step(regs)        ((regs)->msr &= ~MSR_SE)
 #endif
 
-static int generic_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 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");
@@ -375,7 +382,13 @@ static int generic_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);
 
@@ -403,7 +416,14 @@ static int generic_machine_check_exception(struct pt_regs *regs)
                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);
 
@@ -421,7 +441,14 @@ static int generic_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) {
@@ -451,22 +478,26 @@ static int generic_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;
 
-       /* See if any machine dependent calls */
+       /* See if any machine dependent calls. In theory, we would want
+        * to call the CPU first, and call the ppc_md. one if the CPU
+        * one returns a positive number. However there is existing code
+        * that assumes the board gets a first chance, so let's keep it
+        * that way for now and fix things later. --BenH.
+        */
        if (ppc_md.machine_check_exception)
                recover = ppc_md.machine_check_exception(regs);
-       else
-               recover = generic_machine_check_exception(regs);
+       else if (cur_cpu_spec->machine_check)
+               recover = cur_cpu_spec->machine_check(regs);
 
-       if (recover)
+       if (recover > 0)
                return;
 
        if (user_mode(regs)) {
@@ -476,7 +507,12 @@ void machine_check_exception(struct pt_regs *regs)
        }
 
 #if defined(CONFIG_8xx) && defined(CONFIG_PCI)
-       /* the qspan pci read routines can cause machine checks -- Cort */
+       /* the qspan pci read routines can cause machine checks -- Cort
+        *
+        * yuck !!! that totally needs to go away ! There are better ways
+        * to deal with that than having a wart in the mcheck handler.
+        * -- BenH
+        */
        bad_page_fault(regs, regs->dar, SIGBUS);
        return;
 #endif